losartan-potassium and Fibrosis

Historically, the identity of O2-sensing renal erythropoietin (Epo)-producing (REP) cells was a matter of debate. This review summarizes how recent breakthroughs in transgenic mouse and in-situ hybridization techniques have facilitated sensitive and specific detection of REP cells and accelerated advancements in the understanding of the regulation of renal Epo production in health and disease.. REP cells are a dynamically regulated unique subpopulation of tubulointerstitial cells with features of fibroblasts, pericytes and neurons. Under normal conditions, REP cells are located in the corticomedullary border region within a steep decrement in O2 availability. During the progression of chronic kidney disease (CKD), REP cells cease Epo production, dedifferentiate and contribute to the progression of renal fibrosis. However, CKD patients with renal anaemia still respond with elevated Epo production following treatment with hypoxia-mimicking agents.. We hypothesize that REP cells are neuron-like setpoint providers and controllers, which integrate information about blood O2 concentration and local O2 consumption via tissue pO2, and combine these inputs with intrinsic negative feedback loops and perhaps tubular cross-talk, converging in Epo regulation.

Topics: Anemia; Animals; Cell Dedifferentiation; Erythropoietin; Fibrosis; Humans; Kidney; Mice, Transgenic; Oxygen; Renal Insufficiency, Chronic

Renal fibrosis is a major hallmark of chronic kidney disease that is considered to be a common end point of various types of renal disease. To date, the biological meaning of fibrosis during the progression of chronic kidney diseases is unknown and possibly depends on the cell type contributing to extracellular matrix production. During the past decade, the origin of myofibroblasts in the kidney has been intensively investigated. Determining the origins of renal myofibroblasts is important because these might account for the heterogeneous characteristics and behaviors of myofibroblasts. Current data strongly suggest that collagen-producing myofibroblasts in the kidney can be derived from various cellular sources. Resident renal fibroblasts and cells of hematopoietic origin migrating into the kidney seem to be the most important ancestors of myofibroblasts. It is likely that both cell types communicate with each other and also with other cell types in the kidney. In this review, we will discuss the current knowledge on the origin of scar-producing myofibroblasts and cellular events triggering fibrosis.

Topics: Actins; Anemia; Animals; Cell Movement; Disease Progression; Epithelial-Mesenchymal Transition; Erythropoietin; Extracellular Matrix; Fibroblasts; Fibrosis; Humans; Kidney; Models, Biological; Myofibroblasts; Pericytes; Renal Insufficiency, Chronic

Renal pericytes have been neglected for many years, but recently they have become an intensively studied cell population in renal biology and pathophysiology. Pericytes are stromal cells that support vasculature, and a subset of pericytes are mesenchymal stem cells. In kidney, pericytes have been reported to play critical roles in angiogenesis, regulation of renal medullary and cortical blood flow, and serve as progenitors of interstitial myofibroblasts in renal fibrogenesis. They interact with endothelial cells through distinct signaling pathways and their activation and detachment from capillaries after acute or chronic kidney injury may be critical for driving chronic kidney disease progression. By contrast, during kidney homeostasis it is likely that pericytes serve as a local stem cell population that replenishes differentiated interstitial and vascular cells lost during aging. This review describes both the regenerative properties of pericytes as well as involvement in pathophysiologic conditions such as fibrogenesis.

Topics: Acute Kidney Injury; Erythropoietin; Fibrosis; Humans; Kidney; Mesenchymal Stem Cells; Neovascularization, Physiologic; Pericytes; Regeneration; Renal Insufficiency, Chronic

Erythropoietin(EPO) is an indispensable erythropoietic hormone, produced mainly from kidneys in adult, and the production declines with progression of chronic kidney disease(CKD). Renal EPO-producing cells(REPs) are peri-tubular interstitial fibroblasts. Dysfunction and myofibroblast transformation of REPs have been reported in rodent models of kidney injuries. Despite the crucial importance of EPO in health and diseases, many aspects of REPs remain to be elucidated because of technical difficulties to investi- gate the cells in vivo. This review will summarize our recent progress in characterization of REPs. We also summarize the role REPs play in kidney fibrosis and their unique character "plasticity". Future therapeutic approach targeting REPs to treat both anemia and fibrosis in CKD will also be discussed.

Topics: Animals; Erythropoietin; Fibrosis; Humans; Introns; Kidney Diseases; Oxygen

Topics: Animals; Epoetin Alfa; Erythropoietin; Fibrosis; Hematinics; Humans; Kidney; Recombinant Proteins; Renal Insufficiency, Chronic

Hypoxia-inducible factor (HIF) is a transcriptional master regulator that takes control of the gene expressions under hypoxia. Several lines of evidence have shown that chronic hypoxia in tubulointerstitium results in irreversible renal disease. Recently, HIF1 was reported to organize a cluster of histone-modifying enzymes by binding to their promoter regions in various kinds of cell lines. However, its function in renal disease remains largely unknown. We focused on the epigenetic regulation on the progression of chronic kidney disease and have reviewed the latest knowledge in this area with special emphasis on the involvement of HIF. For example, a set of HIF1 downstream target genes also were reported to be regulated by cooperative combination of HIF1 and histone demethylase. We suggest a novel epigenetic pathway that affects the final common pathway to end-stage renal disease in addition to the tubulointerstitial hypoxia. We emphasize the importance of figuring out the epigenetic mechanisms of renal failure to find the novel therapeutic approach of chronic kidney disease.

Topics: Chromatin Assembly and Disassembly; Diabetic Nephropathies; Epigenesis, Genetic; Erythropoietin; Fibrosis; Humans; Hypoxia-Inducible Factor 1; Kidney Failure, Chronic; Kidney Tubules

Kidneys are among the organs affected by the aging process. Aging kidneys are characterized by progressive scarring and measurable declines in renal function. Deficiencies in renal function are associated with mortality in all populations. Therefore, if the kidneys age at an accelerated rate relative to the other organs in a particular individual, then slowing or reversing the kidney aging process may be a therapeutically useful strategy. In this review, we will discuss the physiology and pathogenesis of kidney aging and analyze potential therapeutic strategies for halting the aging process in the kidneys.

Topics: Aging; Animals; Caloric Restriction; Erythropoietin; Fibrosis; Glucuronidase; Humans; Insulin; Insulin Secretion; Kidney; Klotho Proteins; Nephrons; Signal Transduction; Sirtuin 1; Vitamin D

Multiple and complex abnormalities of hemostasis are revealed by laboratory tests in such common diseases as cirrhosis and end-stage renal insufficiency. Because these abnormalities are associated with a bleeding tendency, a causal relationship is plausible. Accordingly, an array of transfusional and nontransfusional medications that improve or correct these abnormalities is used to prevent or stop hemorrhage. However, recent data indicate that the use of hemostatic drugs is scarcely justified mechanistically or clinically. In patients with uremia, the bleeding tendency (mainly expressed by gastrointestinal bleeding and hematoma formation at kidney biopsy) is reduced dramatically by the improvement of anemia obtained with the regular use of erythropoietin. In cirrhosis, the most severe and frequent hemorrhagic symptom (acute bleeding from esophageal varices) is not explained by abnormalities in such coagulation screening tests as the prothrombin and partial thromboplastin times, because formation of thrombin the final coagulation enzyme is rebalanced by low naturally occurring anticoagulant factors in plasma that compensate for the concomitant decrease of procoagulants. Rebalance also occurs for hyperfibrinolysis and platelet abnormalities. These findings are consistent with clinical observations that transfusional and nontransfusional hemostatic medications are of little value as adjuvants to control bleeding in advanced liver disease. Particularly in uremia, but also in cirrhosis, thrombosis is becoming a cogent problem.

Topics: Anemia; Anticoagulants; Blood Coagulation; Blood Coagulation Disorders; Coagulants; Erythropoietin; Fibrosis; Hemorrhage; Hemostasis; Humans; Kidney Diseases; Liver Diseases; Partial Thromboplastin Time; Risk Factors; Uremia

The use of erythropoietin (EPO) has revolutionized the treatment of anaemia associated with many conditions including chronic kidney disease (CKD). However, little is known of the cellular impact of EPO on the uraemic heart. The discovery that the EPO receptor (EPOR) is also expressed on non-haematopoietic cells including cardiomyocytes highlights a role of EPO beyond haematopoiesis. Animal models of heart failure have shown EPO can potentially reverse cardiac remodelling and improve myocardial function. Damage to the kidney, during uraemia, results in a decreased EPO production, which may render the uraemic heart more susceptible to damage and heart failure. Here we review current data on the cellular actions of EPO in models of left ventricular hypertrophy and heart failure and highlight parallels with the uraemic heart.

Topics: Cardiomyopathies; Erythropoietin; Fibrosis; Humans; Hypertrophy, Left Ventricular; Myocardium; Receptors, Erythropoietin; Risk Factors; Signal Transduction; Uremia; Ventricular Remodeling

The renal interstitial compartment, situated between basement membranes of epithelia and vessels, contains two contiguous cellular networks. One network is formed by interstitial fibroblasts, the second one by dendritic cells. Both are in intimate contact with each other. Fibroblasts are interconnected by junctions and connected to basement membranes of vessels and tubules by focal adhesions. Fibroblasts constitute the "skeleton" of the kidney. In the renal cortex, fibroblasts produce erythropoietin and are distinguished from other interstitial cells by their prominent F-actin cytoskeleton, abundance of rough endoplasmic reticulum, and by ecto-5'-nucleotidase expression in their plasma membrane. The resident dendritic cells belong to the mononuclear phagocyte system and fulfil a sentinel function. They are characterized by their expression of MHC class II and CD11c. The central situation of fibroblasts suggests that signals from tubules, vessels, and inflammatory cells converge in fibroblasts and elicit an integrated response. Following tubular damage and inflammatory signals fibroblasts proliferate, change to the myofibroblast phenotype and increase their collagen production, potentially resulting in renal fibrosis. The acquisition of a profibrotic phenotype by fibroblasts in renal diseases is generally considered a main causal event in the progression of chronic renal failure. However, it might also be seen as a repair process.

Topics: 5'-Nucleotidase; Actins; Animals; Dendritic Cells; Erythropoietin; Fibroblasts; Fibrosis; Humans; Kidney Cortex; Kidney Failure, Chronic; Mice; Nephritis, Interstitial

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Disease Progression; Drug Design; Erythropoietin; Fibrosis; Humans; Hypoxia-Inducible Factor 1; Kidney; Kidney Diseases; Nephrology; Renin-Angiotensin System

Nephrogenic systemic fibrosis is a new disorder reported almost exclusively in patients who have renal insufficiency and are exposed to contrast media formulated with gadolinium. High morbidity and mortality are associated with this severely disabling and painful condition. The acute phase begins upon exposure to gadolinium contrast media, characterized by a systemic inflammatory response involving iron mobilization, and then as a progressive, chronic phase in which fibrosis develops. Proposed is a unifying model of cumulative risk factors in which the interplay of systemic inflammation and stimulated hematopoietic environment associated with hyperparathyroidism and erythropoietin may tie to a common pathogenic mechanism of fibrogenesis. Because there are no uniformly effective interventions to treat nephrogenic systemic fibrosis other than successful renal transplantation, prevention by avoiding gadolinium contrast media in patients with chronic kidney disease is vital. On the basis of suspected pathogenesis, it is also reasonable to limit erythropoietin and iron therapy to dosages ensuring recommended targets and adequately control hyperparathyroidism. Herein is reviewed what is currently known about this subject.

Topics: Blood Vessels; Erythropoietin; Fibrosis; Gadolinium; Humans; Inflammation; Iron; Renal Insufficiency

Renal cortical fibroblasts have key roles in mediating intercellular communication with neighboring/infiltrating cells and extracellular matrix (ECM) and maintenance of renal tissue architecture. They express a variety of cytokines, chemokines, growth factors and cell adhesion molecules, playing an active role in paracrine and autocrine interactions and regulating both fibrogenesis and the interstitial inflammatory response. They additionally have an endocrine function in the production of epoetin. Tubulointerstitial fibrosis, the common pathological consequence of renal injury, is characterized by the accumulation of extracellular matrix largely due to excessive production in parallel with reduced degradation, and activated fibroblasts characterized by a myofibroblastic phenotype. Fibroblasts in the kidney may derive from resident fibroblasts, from the circulating fibroblast population or from haemopoetic progenitor or stromal cells derived from the bone marrow. Cells exhibiting a myofibroblastic phenotype may derive from these sources and from tubular cells undergoing epithelial to mesenchymal transformation in response to renal injury. The number of interstitial myofibroblasts correlates closely with tubulointerstitial fibrosis and progressive renal failure. Hence inhibiting myofibroblast formation may be an effective strategy in attenuating the development of renal failure in kidney disease of diverse etiology.

Topics: Animals; Bone Marrow Cells; Cell Communication; Erythropoietin; Fibroblasts; Fibrosis; Humans; Kidney Cortex; Kidney Tubules; Renal Insufficiency; Stromal Cells

Several factors are involved in conditioning renal anemia, and a critical role is attributed to parathyroid hormone (PTH) oversecretion, which has some direct effects on endogenous erythropoietin (EPO) synthesis, bone marrow erythroid progenitors, and red cell survival. Indirect effects are mainly based on the induction of bone marrow fibrosis. Indirect evidence of the role of PTH is based on the observation that parathyroidectomy, when performed in uremic patients, is often followed by restoration of the hematocrit. The interpretations of such positive results are based on the observation of the restored bone marrow space after operation and also in a rise of immunoreactive EPO serum concentrations observed in the first weeks after gland removal. Another field of clinical interest is the possible beneficial effects of vitamin D therapy in controlling PTH secretion, which in turn determines an improvement of anemia of uremic subjects. Several uncontrolled studies confirmed this possibility, indicating that patients who respond to calcitriol or its analogs also show an increase of their hemoglobin levels. Thus, a combined therapeutic approach to PTH oversecretion and anemia is possible by intravenous calcitriol or parathyroidectomy pointing to the possible reversibility of bone marrow fibrosis, which is a common feature of secondary hyperparathyroidism. The increased sensitivity to EPO therapy can also induce a successful reduction of its dosage, thus allowing an interesting reduction of costs.

Topics: Anemia; Bone Marrow; Erythropoiesis; Erythropoietin; Fibrosis; Humans; Hyperparathyroidism; Parathyroid Hormone; Parathyroidectomy; Uremia; Vitamin D

Somatic cell gene therapy has made considerable progress last five years and has shown clear success in some clinical trials. In the field of nephrology, both the elucidation of pathophysiology of renal diseases and the development of gene transfer technique have become driving force for new therapy of incurable renal diseases, such as Alport syndrome and polycystic kidney disease. Gene therapy of renal cancer, although its application is limited to advanced cancer, is the front-runner of clinical application. Erythropoietin gene therapy has provided encouraging results for the treatment of anemia in uremic rats and recently progressed to the inducible one in response to hypoxia. Gene therapy for glomerulonephritis and renal fibrosis showed prominent impact on experimental models, although the safety must be confirmed for prolonged treatment. Transplant kidney is an ideal material for gene modification and induction of tolerance in the transplant kidney is an attractive challenge. Emerging techniques are becoming available such as stem cell technology and messenger RNA silencing strategies. We believe that the future of gene therapy research is exciting and promising and it holds an enormous potential for clinical application.

Topics: Adenoviridae; Anemia; Erythropoietin; Fibrosis; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Glomerulonephritis; Humans; Kidney Diseases; Kidney Transplantation; Lentivirus; Polycystic Kidney Diseases; Recombinant Proteins

Topics: Acute Kidney Injury; Animals; Biomarkers; Contrast Media; Endothelin Receptor Antagonists; Endothelin-1; Endotoxemia; Erythropoietin; Fibrosis; Glycopeptides; Heart Failure; Humans; Hypotension; Kidney Failure, Chronic; Peptides, Cyclic; Peritoneal Dialysis; Peritoneum; Prognosis; Recombinant Proteins; Renal Dialysis

Topics: Anemia; Apoptosis; Erythropoietin; Fibrosis; Humans; Hypoxia; Kidney Failure, Chronic; Kidney Tubules; Models, Biological; Oxidative Stress; Recombinant Proteins

Atherosclerotic renal artery stenosis (ARAS) is common in cardiovascular diseases and associated with hypertension, renal dysfunction and/or heart failure. There is a paucity of data about the prevalence and the role of ARAS in the pathophysiology of combined chronic heart failure (CHF) and chronic kidney disease (CKD). We investigated the prevalence in patients with combined CHF/CKD and its association with renal function, cardiac dysfunction and the presence and extent of myocardial fibrosis.. The EPOCARES study (ClinTrialsNCT00356733) investigates the role of erythropoietin in anaemic patients with combined CHF/CKD. Eligible subjects underwent combined cardiac magnetic resonance imaging (cMRI), including late gadolinium enhancement, with magnetic resonance angiography of the renal arteries (MRA).. MR study was performed in 37 patients (median age 74 years, eGFR 37.4 ± 15.6 ml/min, left ventricular ejection fraction (LVEF) 43.3 ± 11.2%), of which 21 (56.8%) had ARAS (defined as stenosis >50%). Of these 21 subjects, 8 (21.6%) had more severe ARAS >70% and 8 (21.6%) had a bilateral ARAS >50% (or previous bilateral PTA). There were no differences in age, NT-proBNP levels and medication profile between patients with ARAS versus those without. Renal function declined with the severity of ARAS (p = 0.03), although this was not significantly different between patients with ARAS versus those without. Diabetes mellitus was more prevalent in patients without ARAS (56.3%) against those with ARAS (23.8%) (p = 0.04). The presence and extent of late gadolinium enhancement, depicting myocardial fibrosis, did not differ (p = 0.80), nor did end diastolic volume (p = 0.60), left ventricular mass index (p = 0.11) or LVEF (p = 0.15). Neither was there a difference in the presence of an ischemic pattern of late enhancement in patients with ARAS versus those without.. ARAS is prevalent in combined CHF/CKD and its severity is associated with a decline in renal function. However, its presence does not correlate with a worse LVEF, a higher left ventricular mass or with the presence and extent of myocardial fibrosis. Further research is required for the role of ARAS in the pathophysiology of combined chronic heart and renal failure.

Topics: Aged; Aged, 80 and over; Analysis of Variance; Atherosclerosis; Cardio-Renal Syndrome; Chi-Square Distribution; Contrast Media; Erythropoietin; Female; Fibrosis; Glomerular Filtration Rate; Heart Failure; Hematinics; Humans; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Male; Meglumine; Middle Aged; Myocardium; Netherlands; Organometallic Compounds; Predictive Value of Tests; Prevalence; Prognosis; Renal Artery; Renal Artery Obstruction; Renal Insufficiency, Chronic; Risk Assessment; Risk Factors; Severity of Illness Index; Stroke Volume; Ventricular Function, Left

Hypoxia-inducible factor-prolyl hydroxylase (HIF-PHD) inhibitors are therapeutic agents for renal anemia that work through HIF2-mediated upregulation of erythropoietin (EPO) and have also been reported to suppress renal fibrosis. Group 2 innate lymphoid cells (ILC2s) have been proven to be involved in the pathogenesis of fibrosis in various organs, including the kidney. However, the relationship between the HIF pathway, renal fibrosis, and kidney ILC2s remains unclear. In the present study, we found that HIF activation by HIF-PHD inhibitors suppressed type 2 cytokine production from kidney ILC2s. The enhanced HIF pathway downregulated the IL-33 receptor ST2L on ILC2s, and phosphorylation of downstream p38 MAPK was attenuated. M2 macrophages that promote renal fibrosis were polarized by ILC2 supernatants, but reduced cytokine production from ILC2s treated with HIF-PHD inhibitors suppressed this polarization. Our findings suggest that HIF-PHD inhibitors are potential therapeutic agents for renal fibrosis that are mediated by the alteration of ILC2 function.

Topics: Erythropoietin; Fibrosis; Humans; Hypoxia-Inducible Factor-Proline Dioxygenases; Immunity, Innate; Kidney; Kidney Diseases; Lymphocytes; Macrophage Activation; Prolyl Hydroxylases; Prolyl-Hydroxylase Inhibitors

Renal fibrosis is the final manifestation of chronic kidney disease (CKD); its prevention is vital for controlling CKD progression. Indoxyl sulfate (IS), a typical sulfate-conjugated uremic solute, is produced in the liver via the enzyme sulfotransferase (SULT) 1A1 and accumulates significantly during CKD. We investigated the toxicopathological role of IS in renal fibrosis using

Topics: Animals; Disease Models, Animal; Erythropoietin; Fibrosis; Humans; Indican; Inflammation; Kidney; Mice; Mice, Inbred C57BL; Renal Insufficiency, Chronic; Sulfotransferases; Ureteral Obstruction

Chronic kidney disease involves disturbances in iron metabolism including anemia caused by insufficient erythropoietin (EPO) production. However, underlying mechanisms responsible for the dysregulation of cellular iron metabolism are incompletely defined. Using the unilateral ureteral obstruction (UUO) model in

Topics: Anemia; Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Hypoxia; Disease Models, Animal; Erythropoietin; Ferritins; Fibrosis; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-Inducible Factor-Proline Dioxygenases; Iron; Iron Regulatory Protein 1; Kidney; Male; Mice, Inbred C57BL; Mice, Knockout; Procollagen-Proline Dioxygenase; Receptors, Transferrin; Renal Insufficiency; Ureteral Obstruction

Erythropoietin (EPO) is regulated by hypoxia-inducible factor (HIF)-2. In the kidney, it is produced by cortico-medullary perivascular interstitial cells, which transdifferentiate into collagen-producing myofibroblasts in response to injury. Inhibitors of prolyl hydroxylase domain (PHD) dioxygenases (HIF-PHIs) activate HIF-2 and stimulate kidney and liver EPO synthesis in patients with anemia of chronic kidney disease (CKD). We examined whether HIF-PHIs can reactivate EPO synthesis in interstitial cells that have undergone myofibroblast transdifferentiation in established kidney fibrosis.. We investigated Epo transcription in myofibroblasts and characterized the histological distribution of kidney Epo transcripts by RNA in situ hybridization combined with immunofluorescence in mice with adenine nephropathy (AN) treated with HIF-PHI molidustat.  Lectin absorption chromatography was used to assess liver-derived EPO.  In addition, we examined kidney Epo transcription in Phd2 knockout mice with obstructive nephropathy.. In AN, molidustat-induced Epo transcripts were not found in areas of fibrosis and did not colocalize with interstitial cells that expressed α-smooth muscle actin, a marker of myofibroblast transdifferentiation. Epo transcription was associated with megalin-expressing, kidney injury molecule 1-negative nephron segments and contingent on residual renal function. Liver-derived EPO did not contribute to serum EPO in molidustat-treated mice. Epo transcription was not associated with myofibroblasts in Phd2 knockout mice with obstructive nephropathy.. Our studies suggest that HIF-PHIs do not reactivate Epo transcription in interstitial myofibroblasts and that their efficacy in inducing kidney EPO in CKD is dependent on the degree of myofibroblast formation, the preservation of renal parenchyma and the level of residual renal function.

Topics: Animals; Cell Transdifferentiation; Erythropoietin; Fibrosis; Hypoxia-Inducible Factor-Proline Dioxygenases; Kidney; Mice; Mice, Knockout; Myofibroblasts; Nephrons; Prolyl Hydroxylases; Renal Insufficiency, Chronic

Erythropoietin (Epo) is produced by a subpopulation of resident fibroblasts in the healthy kidney. We have previously demonstrated that, during kidney fibrosis, kidney fibroblasts including Epo-producing cells transdifferentiate into myofibroblasts and lose their Epo-producing ability. However, it remains unclear whether Epo-producing cells survive and transform into myofibroblasts during fibrosis because previous studies did not specifically label Epo-producing cells in pathophysiological conditions. Here, we generated Epo

Topics: Animals; Erythropoietin; Fibroblasts; Fibrosis; Kidney; Mice; Ureteral Obstruction

Erythrocyte mass contributes to maintaining systemic oxygen delivery and blood viscosity, with the latter being one of the determinants of blood pressure. However, the physiological response to blood pressure changes under anaemic conditions remain unknown.. We show that anaemia decreases blood pressure in human patients and mouse models. Analyses of pathways related to blood pressure regulation demonstrate that anaemia enhances the expression of the gene encoding the vasopressor substance renin in kidneys. Although kidney juxtaglomerular cells are known to continuously produce renin, renal interstitial fibroblasts are identified in the present study as a novel site of renin induction under anaemic hypotensive conditions in mice and rats. Notably, some renal interstitial fibroblasts are found to simultaneously express renin and the erythroid growth factor erythropoietin in the anaemic mouse kidney. Antihypertensive agents but not hypoxic stimuli induced interstitial renin expression, suggesting that blood pressure reduction triggers interstitial renin induction in anaemic mice. The interstitial renin expression was also detected in injured fibrotic kidneys of the mouse and human, and the renin-expressing interstitial cells in murine fibrotic kidneys were identified as myofibroblasts originating from renal interstitial fibroblasts. Since the elevated expression levels of renin in fibrotic kidneys along with progression of renal fibrosis were well correlated to the systemic blood pressure increase, the renal interstitial renin production seemed to affect systemic blood pressure.. Renal interstitial fibroblasts function as central controllers of systemic oxygen delivery by producing both renin and erythropoietin.. Grants-in-Aid from Japan Society for the Promotion of Science (JSPS) KAKENHI (17K19680, 15H04691, and 26111002) and the Takeda Science Foundation.

Topics: Aged; Anemia; Animals; Biomarkers; Blood Pressure; Chronic Disease; Disease Models, Animal; Erythropoietin; Female; Fibroblasts; Fibrosis; Gene Expression; Humans; Hypotension; Hypoxia; Kidney; Kidney Diseases; Male; Mice; Mice, Knockout; Mice, Transgenic; Middle Aged; Renin; Signal Transduction

Kidney fibrosis is characterized by the development of myofibroblasts originating from resident kidney and immigrating cells. Myofibroblast formation and extracellular matrix production during kidney damage are triggered by various cytokines. Among these, transforming growth factor β1 (TGFβ1) is considered a central trigger for kidney fibrosis. We found a highly upregulated expression of TGFβ1 and TGFβ receptor 2 (TGFβ-R2) mRNAs in kidney interstitial cells in experimental fibrosis. Here, we investigated the contribution of TGFβ1 signaling in resident kidney interstitial cells to organ fibrosis using the models of adenine induced nephropathy and unilateral ureteral occlusion in mice. For this purpose TGFβ1 signaling was interrupted by inducible deletion of the TGFβ-R2 gene in interstitial cells expressing the fibroblast marker platelet derived growth factor receptor-β. Expression of profibrotic genes was attenuated up to 50% in kidneys lacking TGFβ-R2 in cells positive for platelet derived growth factor receptor-β. Additionally, deletion of TGFβ-R2 prevented the decline of erythropoietin production in ureter ligated kidneys. Notably, fibrosis associated expression of α-smooth muscle actin as a myofibroblast marker and deposits of extracellular collagens were not altered in mice with targeted deletion of TGFβ-R2. Thus, our findings suggest an enhancing effect of TGFβ1 signaling in resident interstitial cells that contributes to profibrotic gene expression and the downregulation of erythropoietin production, but not to the development of myofibroblasts during kidney fibrosis.

Topics: Animals; Erythropoietin; Fibroblasts; Fibrosis; Gene Expression; Kidney; Mice; Myofibroblasts; Transforming Growth Factor beta; Transforming Growth Factor beta1

Prolyl hydroxylase domain enzyme (PHD) inhibitors are effective in the treatment of chronic kidney disease (CKD)-associated anemia by stabilizing hypoxia inducible factor (HIF), thereby increasing erythropoietin and consequently erythropoiesis. However, concern for CKD progression needs to be addressed in clinical trials. Although pre-clinical studies showed an anti-inflammatory effect in kidney disease models, the effect of PHD inhibitors on kidney fibrosis was inconsistent probably because the effects of HIF are cell type and context dependent. The major kidney erythropoietin-producing cells are pericytes that produce erythropoietin through HIF-2α-dependent gene transcription. The concern for the impact of HIF in pericytes on kidney fibrosis arises from the fact that pericytes are the major precursor cells of myofibroblasts in CKD. Since cells expressing Gli1 fulfill the morphologic and anatomic criteria for pericytes, we induced Gli1

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Erythropoiesis; Erythropoietin; Fibrosis; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-Inducible Factor-Proline Dioxygenases; Kidney; Mice; Pericytes

The number of patients with end stage kidney disease (ESKD) are increasing world-side. While interstitial fibrosis (IF) is a common step for the progression to ESKD, therapeutic options for IF is still limited in clinical settings. We have reported that bone marrow-derived fibrotic cell, fibrocyte, is involved in the pathogenesis of kidney fibrosis. Also recent studies revealed that erythropoietin has protective effect on kidney diseases. However, it is unknown whether erythropoietin (EPO) inhibits fibrosis in progressive kidney injury. Therefore, we explored the impacts of EPO on kidney fibrosis with focusing on fibrocyte.. Fibrocyte was differentiated from peripheral mononuclear cells of healthy donor. Fibrocyte was stimulated with transforming growth factor beta (TGF)-β with/without EPO treatment. Moreover, the therapeutic effect of EPO was evaluated in murine unilateral ureteral obstruction (UUO) model.. TGF-β stimulation increased the expression of COL1 mRNA in fibrocyte. EPO signal reduced the expression of COL1 mRNA in dose dependent manner. EPO reduced mitochondrial oxidative stress and ameliorated mitochondrial membrane depolarization induced by TGF-β stimulation. Moreover, EPO reduced the mRNA expression of mitochondria related molecules, TRAF6, in fibrocyte. In addition, the count of CD45+/αSMA + double-positive fibrocyte was decreased in the EPO-administered UUO kidneys.. EPO signals function to prevent kidney fibrosis, particularly in fibrocyte. Regulating the renal accumulation of fibrocyte is a part of the anti-fibrotic functions of EPO.

Topics: Animals; Bone Marrow Cells; Cells, Cultured; Collagen; Disease Models, Animal; Disease Progression; Erythropoietin; Fibrosis; Humans; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; RNA, Messenger; Transforming Growth Factor beta

Prolyl hydroxylase (PHD) inhibitors are being developed as alternatives to recombinant human erythropoietin (rHuEPO) for the treatment of anemia in patients with chronic kidney disease (CKD). However, the effects of PHD inhibitors and rHuEPO on blood pressure and CKD in animal models susceptible to hypertension and nephropathy have not been studied. The present study compared the effects of dimethyloxaloylglycine (DMOG), a PHD inhibitor, and rHuEPO on the development of hypertension and renal injury in Dahl salt-sensitive rats fed an 8% salt diet for 3 weeks. DMOG and rHuEPO were equally effective at raising hemoglobin levels. Systolic blood pressure rose to a greater extent in rHuEPO-treated rats (267 ± 10 vs. 226 ± 4 mm Hg) than in rats given DMOG (189 ± 8 mm Hg). Urinary protein excretion increased to 568 ± 54 versus 353 ± 25 mg/day in rats treated with rHuEPO and vehicle; however, it only rose to 207 ± 21 mg/day in rats receiving DMOG. DMOG significantly attenuated the degree of glomerulosclerosis and renal interstitial fibrosis as compared with that in vehicle and rHuEPO-treated rats. This was associated with lower renal levels of monocyte chemoattractant protein-1 and interleukin-1

Topics: Amino Acids, Dicarboxylic; Anemia; Animals; Blood Pressure; Dose-Response Relationship, Drug; Erythropoietin; Fibrosis; Hemoglobins; Hypertension; Kidney; Male; Oxidative Stress; Prolyl Hydroxylases; Prolyl-Hydroxylase Inhibitors; Rats; Rats, Inbred Dahl; Recombinant Proteins; Renal Insufficiency, Chronic; Sodium Chloride, Dietary; Vascular Endothelial Growth Factor A

Topics: Animals; Cyclosporine; Cytokines; Erythropoietin; Fibrosis; Inflammation; Kidney; Male; PPAR gamma; Rats; Rats, Sprague-Dawley; Renal Insufficiency, Chronic; Toll-Like Receptor 4; Transforming Growth Factor beta1

Mesenchymal stem cell (MSC)-based cell transplantation is an effective means of treating chronic liver injury, fibrosis and end-stage liver disease. However, extensive studies have found that only a small number of transplanted cells migrate to the site of injury or lesion, and repair efficacy is very limited.. Bone marrow-derived MSCs (BM-MSCs) were generated that overexpressed the erythropoietin (EPO) gene using a lentivirus. Cell Counting Kit-8 was used to detect the viability of BM-MSCs after overexpressing EPO. Cell migration and apoptosis were verified using Boyden chamber and flow cytometry, respectively. Finally, the anti-fibrosis efficacy of EPO-MSCs was evaluated in vivo using immunohistochemical analysis.. EPO overexpression promoted cell viability and migration of BM-MSCs without inducing apoptosis, and EPO-MSC treatment significantly alleviated liver fibrosis in a carbon tetrachloride (CCl. EPO-MSCs enhance anti-fibrotic efficacy, with higher cell viability and stronger migration ability compared with treatment with BM-MSCs only. These findings support improving the efficiency of MSCs transplantation as a potential therapeutic strategy for liver fibrosis.

Topics: Animals; Erythropoietin; Fibrosis; Liver Cirrhosis; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice

Renal tubulointerstitial fibrosis (TIF) plays an important role in the progression of chronic kidney disease (CKD) and its pathogenesis involves epithelial-to-mesenchymal transition (EMT) upon renal injury. Recombinant human erythropoietin (rhEPO) has been shown to display novel cytoprotective effects, in part by inhibiting transforming growth factor (TGF)-β1-induced EMT. Here, we evaluated the inhibitory effects of microparticles (MPs) derived from human EPO gene-transfected kidney mesenchymal stem cells (hEPO-KMSCs) against TGF-β1-induced EMT in Madin-Darby canine kidney (MDCK) cells and against TIF in mouse kidneys with unilateral ureteral obstruction (UUO).. EMT was induced in MDCK cells by treatment with TGF-β1 (5 ng/mL) for 48 h and then inhibited by co-treatment with rhEPO (100 IU/mL), mock gene-transfected KMSC-derived MPs (MOCK-MPs), or hEPO-KMSC-derived MPs (hEPO-MPs) for a further 48 h. UUO was induced in FVB/N mice, which were then treated with rhEPO (1000 IU/kg, intraperitoneally, every other day for 1 week), MOCK-MPs, or hEPO-MPs (80 μg, intravenously). Alpha-smooth muscle actin (α-SMA), fibronectin, and E-cadherin expression were evaluated in MDCK cells and kidney tissues, and the extent of TIF in UUO kidneys was assessed by immunohistochemical staining.. TGF-β1 treatment significantly increased α-SMA and fibronectin expression in MDCK cells and decreased that of E-cadherin, while co-treatment with rhEPO, MOCK-MPs, or hEPO-MPs markedly attenuated these changes. In addition, rhEPO and hEPO-MP treatment effectively decreased phosphorylated Smad2 and Smad3, as well as phosphorylated p38 mitogen-activated protein kinase (MAPK) expression, suggesting that rhEPO and rhEPO-MPs can inhibit TGF-β1-induced EMT via both Smad and non-Smad pathways. rhEPO and hEPO-MP treatment also significantly attenuated the extent of renal TIF after 1 week of UUO compared to MOCK-MPs, with hEPO-MPs significantly reducing myofibroblast and F4/80+ macrophage infiltration as well as EMT marker expression in UUO renal tissues in a similar manner to rhEPO.. Our results demonstrate that hEPO-MPs modulate TGF-β1-induced EMT in MDCK cells via the Smad2, Smad3, and p38 MAPK pathways and significantly attenuated renal TIF in UUO kidneys.

Topics: Animals; Dogs; Epithelial-Mesenchymal Transition; Erythropoietin; Fibrosis; Humans; Kidney; Madin Darby Canine Kidney Cells; Mesenchymal Stem Cells; RNA, Messenger; Transforming Growth Factor beta1; Ureteral Obstruction

To determine the effects of intraurethral erythropoietin (EPO) on an experimentally induced urethral injury in a rat model with respect to wound healing enhancement and the prevention of spongiofibrosis MATERIAL AND METHODS: A urethral injury model was created by traumatizing the urethra of male rats with a tilted-tip insulin injector. Thirty rats were randomly separated into 3 groups of 10; Group 1 (control) received 0.9% saline solution twice a day, Group II received EPO 25 IU/kg once a day and 0.9% saline solution once a day, and Group III received EPO 25 IU/kg twice a day. All applications were made intraurethrally via a 24 ga catheter sheath. To investigate inflammation and spongiofibrosis and congestion of vessels in the lamina propria, the penises of the rats were harvested for histopathologic evaluation after a follow-up period of 14 days.. Histopathologic analysis revealed less fibrosis and inflammation and higher congestion of vessels in Group III that had received high-dose EPO. There was a significant decrease in both spongiofibrosis and inflammation and an increase in congestion in Groups II and III compared to the control group (P = .001, for all). In the comparison of Group II with Group III, no statistically significant differences were found in terms of these 3 parameters (P = .5, P = .6, P = .27, respectively).. The results of this study have shown that EPO has a preventive effect on spongiofibrosis and improve urethral wound healing in a rat model of urethral injury.

Topics: Animals; Disease Models, Animal; Erythropoietin; Fibrosis; Injections, Intralesional; Male; Random Allocation; Rats; Rats, Wistar; Urethra; Wound Healing

The erythroid growth factor erythropoietin (Epo) is produced by renal interstitial fibroblasts, called REP (renal Epo-producing) cells, in a hypoxia-inducible manner. In chronic kidney disease (CKD), REP cells lose their Epo-production ability, leading to renal anaemia. Concurrently, REP cells are suggested to be transformed into myofibroblasts, which are the major player of renal fibrosis. Although establishment of cultured cell lines derived from REP cells has been a long-term challenge, we here successfully established a REP-cell-derived immortalized and cultivable cell line (Replic cells) by using a genetically modified mouse line. Replic cells exhibited myofibroblastic phenotypes and lost their Epo-production ability, reflecting the situation in renal fibrosis. Additionally, we found that cell-autonomous TGFβ signalling contributes to maintenance of the myofibroblastic features of Replic cells. Furthermore, the promoters of genes for Epo and HIF2α, a major activator of Epo gene expression, were highly methylated in Replic cells. Thus, these results strongly support our contention that REP cells are the origin of myofibroblasts in fibrotic kidneys and demonstrate that cell-autonomous TGFβ signalling and epigenetic silencing are involved in renal fibrosis and renal anaemia, respectively, in CKD. The Replic cell line is a useful tool to further investigate the molecular mechanisms underlying renal fibrosis.

Topics: Anemia; Animals; Cell Line; Disease Models, Animal; Embryo, Mammalian; Epigenesis, Genetic; Erythropoietin; Fibroblasts; Fibrosis; Humans; Kidney; Male; Mice; Mice, Transgenic; Myofibroblasts; Renal Insufficiency, Chronic; Signal Transduction; Transforming Growth Factor beta1

Renal fibrosis and anaemia are two of the most relevant events in chronic kidney disease. Fibrosis is characterized by the accumulation of extracellular matrix proteins in the glomeruli and tubular interstitium. Anaemia is the consequence of a decrease in erythropoietin production in fibrotic kidneys. This work analyses the possibility that the accumulation of abnormal collagens in kidney interstitium could be one of the mechanisms responsible for erythropoietin decreased synthesis. In renal interstitial fibroblast grown on collagen I, erythropoietin mRNA expression and HIF-2α protein decreased, whereas focal adhesion kinase protein (FAK) phosphorylation and proteasome activity increased, compared to cells grown on collagen IV. Proteasome inhibition or FAK inactivation in cells plated on collagen I restored erythropoietin and HIF-2α expression. FAK inhibition also decreased the collagen I-dependent proteasome activation. In a model of tubulointerstitial fibrosis induced by unilateral ureteral obstruction in mice, increased collagen I protein content and an almost complete disappearance of erythropoietin mRNA expression were observed in the ureteral ligated kidney with respect to the contralateral control. Interestingly, erythropoietin synthesis was recovered in obstructed mice treated with proteasome inhibitor. These data suggest that reduced kidney erythropoietin synthesis could be caused by the accumulation of abnormal extracellular matrix proteins.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Line; Collagen Type I; Down-Regulation; Erythropoietin; Extracellular Matrix; Fibroblasts; Fibrosis; Focal Adhesion Protein-Tyrosine Kinases; Humans; Kidney; Mice, Inbred C57BL; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Proteolysis; Renal Insufficiency, Chronic; RNA, Messenger; Ureteral Obstruction

Chronic kidney disease (CKD) is accompanied by a variety of complications, typically renal anemia and kidney fibrosis. Accordingly, it is desirable to develop the novel therapeutics that can treat these CKD conditions. Since nitric oxide (NO) has multiple functions including hypoxia inducible factor stabilizing, anti-inflammatory, anti-oxidative, and anti-apoptoic activities, the use of NO for the CKD therapy has attracted considerable interest. Here, we evaluate the therapeutic impacts of S-nitrosated human serum albumin (SNO-HSA), a long-lasting NO donor, on 2 animal models of CKD. SNO-HSA increased the expression of erythropoietin (EPO), VEGF, and eNOS by stabilizing hypoxia inducible factor-1α in HepG2 and HK-2 cells. SNO-HSA increased hematopoiesis in both healthy and renal anemia rats, suggesting the promotion of EPO production. In unilateral ureteral obstruction-treated mice, SNO-HSA ameliorated kidney fibrosis by suppressing the accumulation of renal extracellular matrix. SNO-HSA also inhibited unilateral ureteral obstruction-induced α-smooth muscle actin increase and E-cadherin decrease, suggesting that SNO-HSA might suppress the accumulation of myofibroblasts, an important factor of fibrosis. SNO-HSA also inhibited the elevations of fibrosis factors, such as transforming growth factor-β, interleukin-6, and oxidative stress, while it increased EPO production, an anti-fibrosis factor. In conclusion, SNO-HSA has the potential to function as a dual therapeutics for renal anemia and kidney fibrosis.

Topics: Anemia; Animals; Cell Line, Tumor; Erythropoietin; Fibrosis; Hep G2 Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Kidney; Male; Mice; Mice, Inbred ICR; Models, Theoretical; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase Type III; Nitroso Compounds; Rats; Rats, Wistar; Renal Insufficiency, Chronic; Serum Albumin, Human; Vascular Endothelial Growth Factor A

The erythropoietin receptor (EpoR) is widely expressed but its renoprotective action is unexplored. To examine the role of EpoR in vivo in the kidney, we induced acute kidney injury (AKI) by ischemia-reperfusion in mice with different EpoR bioactivities in the kidney. EpoR bioactivity was reduced by knockin of wild-type human EpoR, which is hypofunctional relative to murine EpoR, and a renal tubule-specific EpoR knockout. These mice had lower EPO/EpoR activity and lower autophagy flux in renal tubules. Upon AKI induction, they exhibited worse renal function and structural damage, more apoptosis at the acute stage (<7 days), and slower recovery with more tubulointerstitial fibrosis at the subacute stage (14 days). In contrast, mice with hyperactive EpoR signaling from knockin of a constitutively active human EpoR had higher autophagic flux, milder kidney damage, and better renal function at the acute stage but, surprisingly, worse tubulointerstitial fibrosis and renal function at the subacute stage. Either excess or deficient EpoR activity in the kidney was associated with abnormal peritubular capillaries and tubular hypoxia, creating a "U-shaped" relationship. The direct effects of EpoR on tubular cells were confirmed in vitro by a hydrogen peroxide model using primary cultured proximal tubule cells with different EpoR activities. In summary, normal erythropoietin (EPO)/EpoR signaling in renal tubules provides defense against renal tubular injury maintains the autophagy-apoptosis balance and peritubular capillary integrity. High and low EPO/EpoR bioactivities both lead to vascular defect, and high EpoR activity overides the tubular protective effects in AKI recovery.

Topics: Acute Kidney Injury; Animals; Apoptosis; Autophagy; Capillaries; Cell Hypoxia; Cells, Cultured; Disease Models, Animal; Erythropoietin; Fibrosis; Humans; Kidney Tubules, Proximal; Mice, 129 Strain; Mice, Transgenic; Neovascularization, Physiologic; Receptors, Erythropoietin; Signal Transduction

The mechanism underlying the anti‑inflammatory or antifibrotic activity of erythropoietin (EPO) in myocardial fibrosis (MF) remains elusive. In the current study, abdominal aortic constriction (AAC) was performed on rats and EPO and/or Toll‑like receptor (TLR)4 were overexpressed in rat hearts through intramyocardial administration of lentivirus expressing the EPO and TLR4 genes. Hematoxylin and eosin staining and Masson's trichrome staining were performed on tissue sections from rat hearts for histopathological examination. ELISA was used to determine the levels of inflammatory mediators in serum. Gene expression levels were determined by quantitative polymerase chain reaction analysis and protein expression levels were determined by western blot analysis and immunofluorescence staining. The results indicated that EPO overexpression improved MF in rat hearts, by inhibiting the release of transforming growth factor (TGF)‑β1, tumor necrosis factor (TNF)‑α, interleukin (IL)‑6, IL‑1β, IL‑17A, matrix metalloproteinase (MMP)‑9 and MMP‑2. Moreover, EPO overexpression suppressed the expression of TLR4, while promoting phosphoinositide 3‑kinase (PI3K) and phosphorylated AKT serine/threonine kinase 1 (Akt) expression levels. However, the beneficial effects of EPO were attenuated by overexpression of TLR4. In addition, inhibition of PI3K/Akt signaling activity by treatment with LY294002 markedly reversed the protective effect of EPO on the AAC‑induced MF. Taken together, the present study demonstrated that EPO may have a critical role against MF by activating PI3K/Akt signaling and by downregulating TLR4 expression, thereby inhibiting the release of TGF‑β1, TNF‑α, IL‑6, IL‑1β, IL‑17A, MMP‑9 and MMP‑2. These findings suggest that the PI3K/Akt/TLR4 signaling pathway is associated with the anti‑inflammatory effects of EPO and may play a role in attenuating AAC‑induced MF.

Topics: Animals; Cardiomegaly; Cytokines; Erythropoietin; Fibrosis; Gene Expression Regulation; Inflammation; Inflammation Mediators; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Myocardium; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats, Sprague-Dawley; Toll-Like Receptor 4; Transforming Growth Factor beta1

Low birthweight infants have a reduced number of nephrons and are at high risk of chronic kidney disease. Preterm birth and/or intrauterine growth restriction (IUGR) may also affect peritubular capillary development, as has been shown in other organs.. We report two patients with a history of preterm birth and extremely low birthweight who showed polycythemia and renal capillary rarefaction. Patient 1 and 2, born at 25 weeks of gestation with a birthweight of 728 and 466 g, showed mild proteinuria at age 8 and 6 years, respectively. In addition to increasing proteinuria, hemoglobin levels became elevated towards adolescence and their serum erythropoietin (EPO) was high despite polycythemia. Light microscopic examination of renal biopsy specimens showed glomerular hypertrophy, focal segmental glomerulosclerosis, and only mild tubulointerstitial fibrosis. A decrease in the immunohistochemical staining of CD31 and CD34 endothelial cells in renal biopsy specimens was consistent with peritubular capillary rarefaction.. Since kidney function was almost normal and fibrosis was not severe, we consider that the capillary rarefaction and polycythemia associated with elevated EPO levels were largely attributable to preterm birth and/or IUGR.

Topics: Adolescent; Angiotensin II Type 1 Receptor Blockers; Antigens, CD34; Apgar Score; Biopsy; Child; Endothelial Cells; Erythropoietin; Female; Fibrosis; Glomerulosclerosis, Focal Segmental; Hemoglobins; Humans; Infant, Extremely Premature; Infant, Newborn; Infant, Premature, Diseases; Infant, Very Low Birth Weight; Kidney Glomerulus; Kidney Tubules; Male; Microvascular Rarefaction; Nephrons; Platelet Endothelial Cell Adhesion Molecule-1; Polycythemia; Pregnancy; Premature Birth; Proteinuria; Valsartan

The erythropoiesis in hepatitis C virus infection is unclear. We aimed to evaluate the erythropoietic components in chronic hepatitis C (CHC) patients.. The red blood cell (RBC) components, serum erythropoietin (EPO) levels, and their relationship to clinical characteristics were evaluated between 124 age-matched and sex-matched healthy controls and 248 histology-proven CHC patients.. Chronic hepatitis C patients had significantly higher serum levels of EPO (1.44 ± 0.36 log mIU/mL versus 1.03 ± 0.31 log mIU/mL, P < 0.0001) and lower hemoglobin (Hb) concentrations (14.6 ± 1.4 g/dL versus 15.3 ± 1.2 g/dL, P < 0.001) as compared with healthy controls. Among the CHC patients, the serum EPO level was negatively associated with the Hb concentration (β = -0.227; 95% confidence intervals [CI]: -0.09-0.027; P < 0.001) and RBC counts (β = -0.204; 95% CI: -0.245-0.061; P = 0.001) and was positively correlated with necroinflammatory activity (β = 0.201; 95% CI: 0.009-0.046; P = 0.003) and fibrosis (β = 0.143; 95% CI: 0.003-0.076; P = 0.04) of liver histopathology. For non-cirrhotic CHC patients, the severity of liver necroinflammatory activity was positively correlated with the reticulocyte and serum EPO levels (P = 0.001 and 0.008, respectively), and negatively related to the RBC counts (P = 0.03). Using stepwise multivariate linear regression analysis, the grade of necroinflammatory activity was positive (β = 0.214; 95% CI: 0.046-0.209, P = 0.002), whereas the Hb concentration was inversely (β = -0.205; 95% CI: -0.09-0.018, P = 0.004) associated with the serum EPO levels in CHC patients.. The disease activity in CHC patients had a negative impact on erythropoiesis with compensatory higher but blunted EPO responses.

Topics: Adult; Erythrocyte Count; Erythropoiesis; Erythropoietin; Female; Fibrosis; Hemoglobins; Hepatitis C, Chronic; Humans; Inflammation; Liver; Male; Middle Aged; Severity of Illness Index

Renal fibrosis is an inevitable outcome of chronic kidney disease (CKD). Erythropoietin (EPO) has been recently reported to be able to mitigate renal fibrosis. The mechanism underlying the protective effect of EPO, however, remains elusive. In the present study, employing a mouse model of renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction (UUO), we demonstrated that EPO markedly reduced the disruption of the tubular basement membrane (TBM) through attenuating the activation of tissue plasminogen activator (tPA) and matrix metalloproteinase 9 (MMP9), the major matrix proteolytic network in the obstructed kidney. Instead of acting directly on tPA in the kidney, EPO strongly increased the level of circulating microRNA (miR)-144, which was delivered to the injured renal fibroblasts via extracellular vesicles (EVs) to target the tPA 3'-untranslated region and suppress tPA expression. The protective effect of EPO on mouse TBM was inhibited by miR-144 antagomir. Furthermore, in vitro results confirmed that EPO could stimulate bone marrow-derived Sca-1(+)CD44(+)CD11b(-)CD19(-) cells to secrete miR-144-containing EVs, which markedly suppressed tPA expression, as well as metalloproteinase 9 (MMP9) level and activity, in cultured renal fibroblasts. In conclusion, our study provides the first evidence that EPO protects mouse renal TBM through promoting bone marrow cells to generate and secrete miR-144, which, in turn, is efficiently delivered into the mouse kidney via EVs to inhibit the activation of the tPA/MMP9-mediated proteolytic network. This finding thus suggests that EPO, a hormone widely used to treat anemia in CKD, is a potential therapeutic strategy for renal fibrosis.

Topics: 3' Untranslated Regions; Animals; Binding Sites; Bone Marrow Cells; Cell Line; Cytoprotection; Disease Models, Animal; Enzyme Activation; Enzyme Repression; Erythropoietin; Extracellular Vesicles; Fibroblasts; Fibrosis; Glomerular Basement Membrane; Kidney Diseases; Kidney Tubules; Male; Matrix Metalloproteinase 9; Mice; MicroRNAs; Rats; Recombinant Proteins; Signal Transduction; Tissue Plasminogen Activator; Ureteral Obstruction

Renal erythropoietin-producing cells (REPCs) remain in the kidneys of patients with chronic kidney disease, but these cells do not produce sufficient erythropoietin in response to hypoxic stimuli. Treatment with HIF stabilizers rescues erythropoietin production in these cells, but the mechanisms underlying the decreased response of REPCs in fibrotic kidneys to anemic stimulation remain elusive. Here, we show that fibroblast-like FOXD1+ progenitor-derived kidney pericytes, which are characterized by the expression of α1 type I collagen and PDGFRβ, produce erythropoietin through HIF2α regulation but that production is repressed when these cells differentiate into myofibroblasts. DNA methyltransferases and erythropoietin hypermethylation are upregulated in myofibroblasts. Exposure of myofibroblasts to nanomolar concentrations of the demethylating agent 5-azacytidine increased basal expression and hypoxic induction of erythropoietin. Mechanistically, the profibrotic factor TGF-β1 induced hypermethylation and repression of erythropoietin in pericytes; these effects were prevented by 5-azacytidine treatment. These findings shed light on the molecular mechanisms underlying erythropoietin repression in kidney myofibroblasts and demonstrate that clinically relevant, nontoxic doses of 5-azacytidine can restore erythropoietin production and ameliorate anemia in the setting of kidney fibrosis in mice.

Topics: Animals; Azacitidine; Basic Helix-Loop-Helix Transcription Factors; Collagen Type I; Collagen Type I, alpha 1 Chain; DNA Modification Methylases; Erythropoietin; Fibrosis; Mice; Mice, Transgenic; Myofibroblasts; Pericytes; Receptor, Platelet-Derived Growth Factor beta; Renal Insufficiency, Chronic

Renal hypoplasia due to a congenitally reduced number of nephrons progresses to chronic kidney disease and may cause renal anemia, given that the kidneys are a major source of erythropoietin in adults. Hypoplastic kidney (HPK) rats have only about 20% of the normal number of nephrons and develop CKD. This study assessed the renal function and hematologic changes in HPK rats from 70 to 210 d of age. HPK rats demonstrated deterioration of renal excretory function, slightly macrocytic erythropenia at all days examined, age-related increases in splenic hemosiderosis accompanied by a tendency toward increased hemolysis, normal plasma erythropoietin levels associated with increased hepatic and decreased renal erythropoietin production, and maintenance of the response for erythropoietin production to hypoxic conditions, with increased interstitial fibrosis at 140 d of age. These results indicate that increases in splenic hemosiderosis and the membrane fragility of RBC might be associated with erythropenia and that hepatic production of erythropoietin might contribute to maintaining the blood Hgb concentration in HPK rats.

Topics: Age Factors; Anemia; Animals; Biomarkers; Carrier Proteins; Disease Models, Animal; Disease Progression; Erythrocytes; Erythropoietin; Fibrosis; Genetic Predisposition to Disease; Hemolysis; Hemosiderosis; Iron; Kidney; Kidney Diseases; Male; Mutation; Osmotic Fragility; Phenotype; Rats; Rats, Inbred Strains; Renal Insufficiency, Chronic; Spleen

Clinical studies showed that high doses of recombinant human erythropoietin (rHuEPO) used to correct anaemia in chronic kidney disease (CKD) hyporesponsive patients may lead to deleterious effects. The aim of this study was to analyze the effects of rHuEPO in doses usually used to correct CKD-anaemia (100, 200 IU/kg body weight (BW) per week) and in higher doses used in the treatment of hyporesponsive patients (400, 600 IU/kg BW per week), focusing on renal damage, hypoxia, inflammation and fibrosis. Male Wistar rats with chronic renal failure (CRF) induced by 5/6 nephrectomy were treated with rHuEPO or with vehicle, over a 3-week period. Haematological, biochemical and renal function analyses were performed. Kidney and liver mRNA levels were evaluated by quantitative real-time polymerase chain reaction (qPCR) and protein expression by Western blot and immunohistochemistry. Kidney histopathological evaluations were also performed. The CRF group developed anaemia, hypertension and a high score of renal histopathologic lesions. Correction of anaemia was achieved with all rHuEPO doses, with improvement in hypertension, renal function and renal lesions. In addition, the higher rHuEPO doses also improved inflammation. Blood pressure was reduced in all rHuEPO-treated groups, compared to the CRF group, but increased in a dose-dependent manner. The current study showed that rHuEPO treatment corrected anaemia and improved urinary albumin excretion, particularly at lower doses. In addition, it is suggested that a short-term treatment with high doses, used to overcome an episode of hyporesponsiveness to rHuEPO therapy, can present benefits by reducing inflammation, without worsening of renal lesions; however, the pro-hypertensive effect should be considered, and carefully managed to avoid a negative cardiorenal impact.

Topics: Anemia; Animals; Blood Pressure; Body Weight; Cell Hypoxia; Disease Models, Animal; Dose-Response Relationship, Drug; Erythropoietin; Fibrosis; Gene Expression Regulation; Humans; Hypertension; Inflammation; Kidney; Kidney Failure, Chronic; Male; Organ Size; Rats; Recombinant Proteins; Risk; Risk Assessment

In proliferative diabetic retinopathy (PDR), Müller glial cells (MGCs) acquire migratory ability and exhibit a fibroblast-like phenotype. These activated MGCs contribute to the formation of epiretinal membrane, which will stretch the retina, and cause retinal detachment and vitreous hemorrhage. Erythropoietin (Epo) is now found effective in ameliorating renal fibrosis by inhibiting epithelial-to-mesenchymal transition of tubular epithelial cells. This study is undertaken to determine whether Epo has an effect in inhibiting MGCs activation to attenuate epiretinal membrane formation in PDR.. MIO-M1 cell line was used in this study. As a pilot test to determine the most efficient treatment time and concentration of Epo, levels of connective tissue growth factor (CTGF) and transforming growth factor-β (TGF-β) were measured by real-time PCR, after treatment with Epo on MGCs cultured in high glucose. MGCs were cultured in high glucose and normal glucose for 2 days, with or without TGF-β as a pro-fibrogenic cytokine. Epo was introduced at the same time. Immunofluorescence targeting α-smooth muscle actin (α-SMA), fibronectin, and glial fibrillary acidic protein (GFAP) was performed to explore the cell phenotype. Matrix metalloproteinase 9 (MMP9) mRNA level was detected by real-time PCR. Protein levels of CTGF and cytoskeletal proteins like α-SMA and fibronectin were measured by enzyme-linked immunosorbent assay (ELISA) and Western blot respectively. Wound-healing assay was applied to evaluate the migratory ability of MGCs, and actin-tracker green was used to draw the structure of F-actin in MGCs.. After being seeded into high-glucose medium containing TGF-β, MGCs expressed a larger amount of MMP9 mRNA as well as α-SMA, fibronectin at protein level. They secreted more CTGF, and their F-actin reorganized in a parallel manner and showed a stronger ability to migrate. In addition, these changes, including mRNA and protein expression, F-actin assembling, and cell migration, could be attenuated significantly by Epo treatment.. High glucose together with TGF-β promote MGCs to exhibit a fibroblast-like phenotype and develop a greater migratory ability. These changes can be inhibited by Epo, which therefore may contribute to the controlling of epiretinal membrane formation.

Topics: Actins; Blotting, Western; Cell Line; Cell Movement; Connective Tissue Growth Factor; Enzyme-Linked Immunosorbent Assay; Ependymoglial Cells; Erythropoietin; Fibronectins; Fibrosis; Fluorescent Antibody Technique, Indirect; Glial Fibrillary Acidic Protein; Glucose; Humans; Matrix Metalloproteinase 9; Real-Time Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta

The aim of the present study is to investigate the protection effects of bone marrow mesenchymal stem cells (MSCs) in combination with EPO against hyperoxia-induced bronchopulmonary dysplasia (BPD) injury in neonatal mice. BPD model was prepared by continuous high oxygen exposure, 1×106 bone marrow MSCs and 5000U/kg recombinant human erythropoietin (EPO) were injected respectively. Results showed that administration of MSCs, EPO especially MSCs+EPO significant attenuated hyperoxia-induced lung damage with a decrease of fibrosis, radical alveolar counts and inhibition of the occurrence of epithelial-mesenchymal transition (EMT). Furthermore, MSCs+EPO co-treatment more significantly suppressed the levels of transforming growth factor-β1(TGF-β1) than MSCs or EPO alone. Collectively, these results suggested that MSCs, EPO in particular MSCs+EPO co-treatment could promote lung repair in hyperoxia-induced alveoli dysplasia injury via inhibition of TGF-β1 signaling pathway to further suppress EMT process and may be a promising therapeutic strategy.

Topics: Animals; Bronchopulmonary Dysplasia; Cells, Cultured; Combined Modality Therapy; Disease Models, Animal; Epithelial-Mesenchymal Transition; Erythropoietin; Female; Fibrosis; Humans; Hyperoxia; Mesenchymal Stem Cell Transplantation; Mice; Mice, Inbred C57BL; Pulmonary Alveoli; Recombinant Proteins; Signal Transduction; Transforming Growth Factor beta1

Chronic kidney disease (CKD) is often accompanied by impairment of cardiac function that may lead to major cardiac events. Erythropoietin (EPO), a kidney-produced protein, was shown to be beneficial to heart function. It was suggested that reduced EPO secretion in CKD may play a role in the initiation of heart damage.. To investigate molecular changes in the EPO/ erythropoietin receptor (EPO-R) axis in rat cardiomyocytes using a rat model for CKD.. We established a rat model for CKD by kidney resection. Cardiac tissue sections were stained with Masson's trichrome to assess interstitial fibrosis indicating cardiac damage. To evaluate changes in the EPO/EPO-R signaling cascade in the myocardium we measured cardiac EPO and EPO-R as well as the phosphorylation levels of STAT-5, a downstream element in this cascade.. At 11 weeks after resection, animals presented severe renal failure reflected by reduced creatinine clearance, elevated blood urea nitrogen and presence of anemia. Histological analysis revealed enhanced fibrosis in cardiac sections of CKD animals compared to the sham controls. Parallel to these changes, we found that although cardiac EPO levels were similar in both groups, the expression of EPO-R and the activated form of its downstream protein STAT-5 were significantly lower in CKD animals.. CKD results in molecular changes in the EPO/EPO-R axis. These changes may play a role in early cardiac damage observed in the cardiorenal syndrome.

Topics: Anemia; Animals; Disease Models, Animal; Down-Regulation; Erythropoietin; Fibrosis; Kidney Function Tests; Male; Myocardium; Rats; Receptors, Erythropoietin; Renal Insufficiency, Chronic; Signal Transduction; STAT5 Transcription Factor

Persistent alterations of the renal tissue due to maladaptive repair characterize the outcome of acute kidney injury (AKI), despite a clinical recovery. Acute damage may also limit the renal production of erythropoietin, with impairment of the hemopoietic response to ischemia and possible lack of its reno-protective action. We aimed to evaluate the effect of a cell therapy using human CD133

Topics: AC133 Antigen; Acute Kidney Injury; Animals; Disease Models, Animal; Erythropoietin; Fibrosis; Heterografts; Humans; Kidney Tubules; Mice; Mice, SCID; Stem Cell Transplantation; Stem Cells

Erythropoietin (EPO) is a hematopoietic hormone that protects against renal interstitial fibrosis in animal models; however, the mechanism underlying the anti‑fibrotic activity of EPO has remained elusive. The present study aimed to elucidate this mechanism. Twenty‑four male C57BL6 mice were randomly divided into four groups, each comprising six mice: (i) control group (Sh); (ii) unilateral ureteral obstruction (UUO) plus vehicle group (U+V); (ⅲ) UUO plus 300 U/kg body weight recombinant human (rh)EPO (U+E1) and (ⅳ) UUO plus 1,000 U/kg body weight rhEPO (U+E2). Seven days post‑surgery, the mice were sacrificed for examination. UUO induced significant deposition of extracellular matrix, detected by picro‑sirius red staining, which was decreased following rhEPO treatment. UUO also induced deposition of collagen I and fibronectin, rhEPO treatment was able to attenuate this effect at protein and mRNA levels. Compared with the control groups, UUO resulted in the accumulation of α‑smooth muscle actin‑positive cells in the interstitium, an effect which was ameliorated by rhEPO. Furthermore, rhEPO abrogated the UUO‑induced increase in the number of bone marrow‑derived myofibroblasts. Mechanistically, it was discovered that rhEPO decreased CXC chemokine ligand 16 (CXCL16) expression at protein level. However, treatment with rhEPO did not alter the protein expression of CC chemokine ligand 21 or CXCL12. These results suggested that rhEPO decreased fibrocyte accumulation via the suppression of renal CXCL16, which resulted in the attenuation of renal fibrosis.

Topics: Animals; Chemokine CXCL16; Chemokines, CXC; Disease Models, Animal; Disease Progression; Erythropoietin; Fibrosis; Humans; Kidney Diseases; Male; Mice; Myofibroblasts; Receptors, Scavenger; Recombinant Proteins

Anemia is a common complication of chronic kidney disease (CKD) that develops early and its severity increases as renal function declines. It is mainly due to a reduced production of erythropoietin (EPO) by the kidneys; however, there are evidences that iron metabolism disturbances increase as CKD progresses. Our aim was to study the mechanisms underlying the development of anemia of CKD, as well as renal damage, in the remnant kidney rat model of CKD induced by 5/6 nephrectomy. This model of CKD presented a sustained degree of renal dysfunction, with mild and advanced glomerular and tubulointerstitial lesions. Anemia developed 3 weeks after nephrectomy and persisted throughout the protocol. The remnant kidney was still able to produce EPO and the liver showed an increased EPO gene expression. In spite of the increased EPO blood levels, anemia persisted and was linked to low serum iron and transferrin levels, while serum interleukin (IL)-6 and high sensitivity C-reactive protein (hs-CRP) levels showed the absence of systemic inflammation. The increased expression of duodenal ferroportin favours iron absorption; however, serum iron is reduced which might be due to iron leakage through advanced kidney lesions, as showed by tubular iron accumulation. Our data suggest that the persistence of anemia may result from disturbances in iron metabolism and by an altered activity/function of EPO as a result of kidney cell damage and a local inflammatory milieu, as showed by the increased gene expression of different inflammatory proteins in the remnant kidney. In addition, this anemia and the associated kidney hypoxia favour the development of fibrosis, angiogenesis and inflammation that may underlie a resistance to EPO stimuli and reduced iron availability. These findings might contribute to open new windows to identify putative therapeutic targets for this condition, as well as for recombinant human EPO (rHuEPO) resistance, which occurs in a considerable percentage of CKD patients.

Topics: Anemia; Animals; Blood Pressure; Body Weight; Disease Models, Animal; Erythropoietin; Fibrosis; Hepcidins; Inflammation; Iron; Kidney; Liver; Male; Organ Size; Rats; Rats, Wistar; Receptors, Erythropoietin; RNA, Messenger

Mesenchymal stem cells (MSCs) play a central role in the remediation of cell and tissue damage. Erythropoietin (EPO) may enhance the beneficial influence of MSCs during recovery from tissue and organ injuries. Microvesicles (MVs) released from MSCs contribute to the restoration of kidney damage. We studied the influence of EPO on MVs derived from MSCs, and the protective effects of these factors in subjects with chronic kidney disease (CKD).. The MVs derived from untreated MSCs (MSC-MVs) or from MSCs incubated in different concentrations of EPO (1, 10, 100, and 500 IU/ml EPO-MVs) were used to treat renal injury of unilateral ureteral obstruction (UUO) in vivo, and transforming growth factor-β1 (TGF-β1)-induced fibrosis in a human renal proximal tubular epithelial (HK2) cell line in vitro. Western blot and reverse transcription polymerase chain reaction (RT-PCR) analyses were used to evaluate the expression of epithelial and mesenchymal markers in the renal tissue and HK2 cells. Flow cytometry was used to assess apoptosis within the HK2 cells, and microRNA (miRNA) microarray assays were used to determine the expression profiles of miRNA in the MSC-MVs and EPO-MVs.. Compared to MSC-MVs (untreated), there was a significant increase in the number of EPO-MVs derived from MSCs treated with 1-100 IU/ml EPO, and these EPO-MVs had a greater benefit in UUO mice on days 7 and 14. Moreover, the EPO-MVs had a better restorative effect following TGF-β1-induced fibrosis in HK2 cells at 24 h and 48 h. The flow cytometry results revealed that both types of MVs, especially EPO-MVs, play an important anti-apoptotic role in HK2 cells treated with TGF-β1. The miRNA profiles of the MVs revealed that EPO-MVs changed 212 miRNAs (fold-change ≥ 1.5), including miR-299, miR-499, miR-302, and miRNA-200, and that 70.28 % of these changes involved upregulation. The changed miRNA in EPO-MVs may have contributed to their enhanced protective effects following renal injury compared to MSC-MVs.. There was a dose-dependent increase in the level of EPO-MVs within the range of 1-100 IU/ml EPO. Although both MSC-MVs and EPO-MVs protect the kidney from fibrosis-related damage, there is a superior effect of EPO-MVs.

Topics: Actins; Animals; Apoptosis; Bone Marrow Cells; Cadherins; Cell-Derived Microparticles; Cells, Cultured; Disease Models, Animal; Erythropoietin; Fibrosis; Humans; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Renal Insufficiency, Chronic; Transcriptome; Transforming Growth Factor beta1; Ureteral Obstruction

Topics: Anemia; Animals; Cell Hypoxia; Erythropoietin; Fibrosis; Humans; Kidney Diseases; Oxygen

Prevention of fibrosis is a very important therapeutic strategy in the treatment of obstructive nephropathy (ON). The aim of this study is to show and compare the actions of Simvastatin (Simv) and Erythropoietin (Epo) in renal expression of nuclear factor kappa B (NFκB), transforming growth factor-β (TGF-β), basic fibroblast growth factor (bFGF), platelet-derived growth factor B (PDGF-B), fibronectin and development of interstitial fibrosis in rats with unilateral ureteral obstruction (UUO). A total of 48 Sprague-Dawley rats were allocated to 4 groups of sham, Epo, Simv and control. Unilateral ureteral ligation was performed on all rats except the Sham group. For interstitial fibrosis Masson's trichrome stain and for the expression of TGF-β, PDGF-B, bFGF, NFκB and fibronectin, immunohistochemical methods were used. In the Epo and Simv groups, expression of TGF-β and fibronectin and staining with Masson's trichrome were less compared to the control group. In addition, fibronectin expression in the Epo group was less than the Simv group. Unlike the Simv group, NFκB and bFGF expression in the Epo group were less when compared to the control group. Consequently, it was seen that both Epo and Simv prevented fibrosis in ON. Epo was superior in this effect by suppressing the expressions of NFκB and bFGF more effectively than Simv. Based on this finding, Epo might be a better agent than Simv in the prevention of fibrosis in ON.

Topics: Animals; Epoetin Alfa; Erythropoietin; Fibroblast Growth Factor 2; Fibronectins; Fibrosis; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Immunohistochemistry; Kidney; Male; NF-kappa B; Proto-Oncogene Proteins c-sis; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Simvastatin; Transforming Growth Factor beta; Ureteral Obstruction

Treatment of renal ischemia-reperfusion (IR) injury with recombinant human erythropoietin (rhEPO) reduces acute kidney injury and improves function. We aimed to investigate whether progression to chronic kidney disease associated with acute injury was also reduced by rhEPO treatment, using in vivo and in vitro models. Rats were subjected to bilateral 40-min renal ischemia, and kidneys were studied at 4, 7, and 28 days postreperfusion for renal function, tubular injury and repair, inflammation, and fibrosis. Acute injury was modulated using rhEPO (1,000 or 5,000 IU/kg, intraperitoneally) at the time of reperfusion. Renal tubular epithelial cells or fibroblasts in culture were subjected to hypoxia or oxidative stress, with or without rhEPO (200 IU/ml), and fibrogenesis was studied. The results of the in vivo model confirmed functional and structural improvement with rhEPO at 4 days post-IR (P < 0.05). At 7 days post-IR, fibrosis and myofibroblast stimulation were increased with IR with and without rhEPO (P < 0.01). However, at 28 days post-IR, renal fibrosis and myofibroblast numbers were significantly greater with IR plus rhEPO (P < 0.01) compared with IR only. Mechanistically, rhEPO stimulated profibrotic transforming growth factor-β, oxidative stress (marker 8-hydroxy-deoxyguanosine), and phosphorylation of the signal transduction protein extracellular signal-regulated kinase. In vitro, rhEPO protected tubular epithelium from apoptosis but stimulated epithelial-to-mesenchymal transition and also protected and activated fibroblasts, particularly with oxidative stress. In summary, although rhEPO was protective of renal function and structure in acute kidney injury, the supraphysiological dose needed for renoprotection contributed to fibrogenesis and stimulated chronic kidney disease in the long term.

Topics: Acute Kidney Injury; Animals; Apoptosis; Cells, Cultured; Disease Progression; Epoetin Alfa; Erythropoietin; Extracellular Signal-Regulated MAP Kinases; Fibrosis; Humans; Kidney; Kidney Diseases; Male; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Reperfusion Injury; Treatment Outcome

Doxorubicin (DOX) is a highly effective anti-cancer drug with limited clinical use due to its serious cardiotoxicity. Recent studies reported that erythropoietin (EPO) could exert a cardioprotective effect by non-erythropoietic effects. This study was to investigate fibrosis of DOX-induced cardiotoxicity and determine mechanisms of EPO against extracellular matrix (ECM) remodelling.. Rats were grouped as the control group, the DOX group and the DOX+EPO group. DOX (2.5 mg/kg/dose, six doses for two weeks) was administered to induce cardiotoxicity by intraperitoneal injections in the DOX group and the DOX+EPO group, and EPO (2500U/kg/dose, six doses for two weeks) was administered simultaneously in the DOX+EPO group. Two weeks after the last administration, rats were killed with cardiac tissues used for histological analyses and immunological detections for matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2).. Rats treated with DOX showed degenerative changes with cardiac fibrosis. Compared to the control group, the expression of MMP-2 was up-regulated whereas that of TIMP-2 was down-regulated in the DOX group. EPO administration improved cardiac fibrosis, decreased MMP-2 expression, increased TIMP-2 expression and ameliorated imbalance of MMP-2/TIMP-2 ratio.. The present study suggests that EPO can exert a cardioprotective effect on DOX-induced cardiotoxicity which may be associated with improving MMP-2/TIMP-2 imbalance.

Topics: Animals; Antibiotics, Antineoplastic; Cardiotoxins; Down-Regulation; Doxorubicin; Erythropoietin; Fibrosis; Heart Diseases; Male; Matrix Metalloproteinase 2; Rats; Rats, Wistar; Time Factors; Tissue Inhibitor of Metalloproteinase-2; Up-Regulation

Topics: Abdominal Neoplasms; Adolescent; Adult; Basic Helix-Loop-Helix Transcription Factors; Child; DNA Mutational Analysis; Erythropoietin; Exudates and Transudates; Female; Fibrosis; Fluorescein Angiography; Humans; Male; Optic Disk; Pancreatic Neoplasms; Paraganglioma; Polycythemia; Retinal Neovascularization; Somatostatinoma

Cardiovascular disease is the primary cause of mortality in patients with chronic kidney disease (CKD). Heart remodeling in CKD comprises mainly interstitial fibrosis and capillary loss. Beyond correcting renal anemia, erythropoietin (Epo) has potentially beneficial pleiotropic effects on heart remodeling.. 12-week-old male Sprague-Dawley rats were randomized to 5/6 nephrectomy (NX) or sham operation (sham-op); subsequently, they received murine Epo (2.5 μg/kg/week), enalapril (12 mg/kg/day), Epo + enalapril, Epo + dihydralazine (25 mg/kg/day), or vehicle. Heart function and morphology was assessed after 16 weeks of treatment.. Compared with sham-op (81.2%), left ventricle fractional shortening was reduced in vehicle-treated NX (66.3%) and this was ameliorated by Epo (72.6%) and even prevented by enalapril (80.6%). Capillary length density was lower and the area of fibrosis more marked in vehicle-treated NX compared to sham-op. Capillary rarefaction and heart fibrosis were prevented in NX treated with Epo + enalapril and reduced in NX treated with enalapril and Epo + dihydralazine. Despite higher blood pressure, treatment with Epo reduced heart fibrosis but failed to prevent capillary loss. In parallel, expression of the p47phox NADPH oxidase was higher in untreated NX and was effectively reduced in NX treated with Epo + enalapril. Under basal conditions there was no difference between the groups regarding myocardial hypoxia as reflected by pimonidazole staining.. Epo in combination with enalapril caused additive reduction of cardiac fibrosis and microvessel disease in 5/6 nephrectomized rats presumably by decreasing myocardial oxidative stress.

Topics: Albumins; Angiotensin-Converting Enzyme Inhibitors; Animals; Aorta; Apoptosis; Blood Pressure; Drug Synergism; Echocardiography; Enalapril; Erythropoietin; Fibrosis; Heart; Heart Rate; Hemoglobins; Kidney; Kidney Failure, Chronic; Male; Microcirculation; Myocardium; Nephrectomy; Oxidative Stress; Rats; Rats, Sprague-Dawley; Time Factors

Ischemia reperfusion (IR) and cyclosporine A (CsA) injuries are unavoidable in kidney transplantation and are associated with allograft dysfunction. Herein, the effect and mechanism of a novel tissue protective peptide, helix B surface peptide (HBSP) derived from erythropoietin, were investigated in a rat model. The right kidney was subjected to 45 min ischemia, followed by left nephrectomy and 2-week reperfusion, with or without daily treatment of CsA 25 mg/kg and/or HBSP 8 nmol/kg. Blood urea nitrogen was increased by CsA but decreased by HBSP at 1 week and 2 weeks, while the same changes were revealed in urinary protein/creatinine only at 2 weeks. HBSP also significantly ameliorated tubulointerstitial damage and interstitial fibrosis, which were gradually increased by IR and CsA. In addition, apoptotic cells, infiltrated inflammatory cells, and active caspase-3+ cells were greatly reduced by HBSP in the both IR and IR + CsA groups. The 17 kD active caspase-3 protein was decreased by HBSP in the IR and IR + CsA kidneys, with decreased mRNA only in the IR + CsA kidneys. Taken together, it has been demonstrated, for the first time, that HBSP effectively improved renal function and tissue damage caused by IR and/or CsA, which might be through reducing caspase-3 activation and synthesis, apoptosis, and inflammation.

Topics: Acute Kidney Injury; Animals; Apoptosis; Caspase 3; Cyclosporine; Enzyme Activation; Erythropoietin; Fibrosis; Gene Expression; Inflammation; Kidney; Kidney Function Tests; Male; Peptide Fragments; Protective Agents; Rats; Reperfusion Injury; RNA, Messenger

This study aims to investigate the renoprotective effect of recombinant human erythropoietin (rhEPO) treatment could preserve tubular epithelial cell regeneration and ameliorate renal fibrosis by dual inhibition of stress-induced senescence and EMT in unilateral ureteric obstruction (UUO) mouse model. UUO or sham-operated mice were randomly assigned to receive rhEPO or vehicle treatment and were sacrificed on days 3, 7, and 14. Kidney specimens were fixed for histopathological and immunohistochemical study. The expression of S100A4, TGF-β1, BMP-7, Smad2/3, Smad1/5/8, and p16(INK4a) was determined by western blot and real-time RT-PCR. Vehicle treated UUO mice had increased tubular atrophy and interstitial fibrosis within 3 to 14 days. An increase in TGF-β1, Smad2/3, S100A4, and p16(INK4a) expression and a decrease in BMP-7 and Smad1/5/8 expression were observed in the obstructed kidneys. p16(INK4a) was positively correlated with TGF-β1/Smad2/3 and negatively correlated with BMP-7/Smad1/5/8 in UUO mice. rhEPO treatment significantly suppressed the upregulation of TGF-β, Smad2/3, S100A4, and p16(INK4a) and preserved the downregulation of BMP-7 and Smad1/5/8, resulting in markedly reduced TA/IF compared to the vehicle treated mice. The renoprotective effects of rhEPO could ameliorate renal TA/IF by modulating senescence and EMT which could be a part of therapeutic option in patients with chronic kidney disease.

Topics: Animals; Bone Morphogenetic Protein 7; Cellular Senescence; Cyclin-Dependent Kinase Inhibitor p16; Down-Regulation; Epithelial Cells; Epithelial-Mesenchymal Transition; Erythropoietin; Fibrosis; Humans; Kidney Tubules; Male; Mice; Mice, Inbred ICR; Recombinant Proteins; Regeneration; Smad Proteins; Transforming Growth Factor beta1; Up-Regulation; Ureteral Obstruction

The introduction of cyclosporine (CsA) has improved graft survival, but it causes nephropathy, which limits its clinical utility. Recently, we reported that carbamylated erythropoietin (CEPO) protected kidneys from ischemia reperfusion injury as well as EPO. To investigate the clinical applications of CEPO, we next evaluated the long-term therapeutic effect of CEPO using a CsA-induced nephropathy model. CsA caused renal dysfunction, while EPO/CEPO administration significantly improved renal function. EPO treatment significantly increased Hb concentration, while CEPO treatment neither enhanced nor reduced Hb concentration. CsA treatment induced tubular apoptosis, while EPO/CEPO administration inhibited it and increased PI3 kinase activation and Akt phosphorylation. In parallel, morphological assessment revealed that EPO/CEPO significantly reduced CsA-induced interstitial fibrosis and inhibited interstitial macrophage infiltration. In addition, real-time RT-PCR demonstrated that cortical mRNA levels of TGF-β1 and type I collagen were suppressed in the EPO/CEPO group. These results suggest a new therapeutic approach using CEPO to protect kidneys from CsA-induced nephropathy.

Topics: Animals; Apoptosis; Collagen Type I; Cyclosporine; Disease Models, Animal; Dogs; Erythropoiesis; Erythropoietin; Fibrosis; Hemoglobins; Humans; Immunosuppressive Agents; Kidney; Kidney Diseases; Macrophages; Male; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Transforming Growth Factor beta1

The tissue-protective effects of erythropoietin (EPO) have been extensively investigated, and EPO administration can raise the hemoglobin (Hb) concentration. Recently, we reported that carbamylated erythropoietin (CEPO) protected kidneys from ischemia-reperfusion injury as well as EPO.. To investigate the clinical applications of CEPO, we next evaluated the long-term therapeutic effect of CEPO using a tubulointerstitial model rat. We randomized remnant kidney model rats to receive saline, EPO, or CEPO for 8 weeks.. CEPO- and EPO-treated rats had improved serum creatinine levels compared with saline-treated remnant kidney model rats, although the Hb level was significantly increased in EPO-treated rats. Two-photon microscopy revealed that EPO/CEPO significantly ameliorated tubular epithelial cell damage assessed by endocytosis. In addition, CEPO or EPO protected endothelial cells with a sustained blood flow rate. EPO or CEPO suppressed the number of TUNEL-positive apoptotic cells with weak αSMA staining. Furthermore, PCR analysis demonstrated that TGF-β and type I collagen expression was attenuated in EPO- or CEPO-treated rats, accompanied by a significant decrease in interstitial fibrosis.. We established a long-term therapeutic approach to protect tubulointerstitial injury with CEPO, and thus, the therapeutic value of this approach warrants further attention and preclinical studies.

Topics: Animals; Collagen Type I; Creatinine; Disease Models, Animal; Erythropoietin; Fibrosis; Hemoglobins; Kidney; Kidney Diseases; Male; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Transforming Growth Factor beta

Recent studies revealed that erythropoietin (EPO) has tissue-protective effects in the heart by increasing vascular endothelial growth factor (VEGF) expression and attenuating myocardial fibrosis in ischemia models. In this study, we investigated the effect of EPO on ventricular remodeling and blood vessel growth in diabetic rats.. Male SD rats were randomly divided into 3 groups: control rats, streptozotocin (STZ)-induced diabetic rats, and diabetic rats treated with 1000 U/kg EPO by subcutaneous injection once per week. Twelve weeks later, echocardiography was conducted, and blood samples were collected for counting of peripheral blood endothelial progenitor cells (EPCs). Myocardial tissues were collected, quantitative real-time PCR (RT-PCR) was used to detect the mRNA expression of VEGF and EPO-receptor (EPOR), and Western blotting was used to detect the protein expression of VEGF and EPOR. VEGF, EPOR, transforming growth factor beta (TGF-β), and CD31 levels in the myocardium were determined by immunohistochemistry. To detect cardiac hypertrophy, immunohistochemistry of collagen type I, collagen type III, and Picrosirius Red staining were performed, and cardiomyocyte cross-sectional area was measured.. After 12 weeks STZ injection, blood glucose increased significantly and remained consistently elevated. EPO treatment significantly improved cardiac contractility and reduced diastolic dysfunction. Rats receiving the EPO injection showed a significant increase in circulating EPCs (27.85 ± 3.43%, P < 0.01) compared with diabetic untreated animals. EPO injection significantly increased capillary density as well as EPOR and VEGF expression in left ventricular myocardial tissue from diabetic rats. Moreover, EPO inhibited interstitial collagen deposition and reduced TGF-β expression.. Treatment with EPO protects cardiac tissue in diabetic animals by increasing VEGF and EPOR expression levels, leading to improved revascularization and the inhibition of cardiac fibrosis.

Topics: Animals; Blotting, Western; Collagen Type I; Collagen Type III; Diabetes Mellitus, Experimental; Endothelial Cells; Erythropoietin; Fibrosis; Gene Expression Regulation; Hypertrophy, Left Ventricular; Immunohistochemistry; Injections, Subcutaneous; Male; Myocardial Contraction; Myocardium; Neovascularization, Physiologic; Platelet Endothelial Cell Adhesion Molecule-1; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptors, Erythropoietin; Recovery of Function; RNA, Messenger; Stem Cells; Time Factors; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Ventricular Dysfunction, Left; Ventricular Function, Left; Ventricular Remodeling

In chronic kidney disease, fibroblast dysfunction causes renal fibrosis and renal anemia. Renal fibrosis is mediated by the accumulation of myofibroblasts, whereas renal anemia is mediated by the reduced production of fibroblast-derived erythropoietin, a hormone that stimulates erythropoiesis. Despite their importance in chronic kidney disease, the origin and regulatory mechanism of fibroblasts remain unclear. Here, we have demonstrated that the majority of erythropoietin-producing fibroblasts in the healthy kidney originate from myelin protein zero-Cre (P0-Cre) lineage-labeled extrarenal cells, which enter the embryonic kidney at E13.5. In the diseased kidney, P0-Cre lineage-labeled fibroblasts, but not fibroblasts derived from injured tubular epithelial cells through epithelial-mesenchymal transition, transdifferentiated into myofibroblasts and predominantly contributed to fibrosis, with concomitant loss of erythropoietin production. We further demonstrated that attenuated erythropoietin production in transdifferentiated myofibroblasts was restored by the administration of neuroprotective agents, such as dexamethasone and neurotrophins. Moreover, the in vivo administration of tamoxifen, a selective estrogen receptor modulator, restored attenuated erythropoietin production as well as fibrosis in a mouse model of kidney fibrosis. These findings reveal the pathophysiological roles of P0-Cre lineage-labeled fibroblasts in the kidney and clarify the link between renal fibrosis and renal anemia.

Topics: Anemia; Animals; Benserazide; Cell Differentiation; Cell Lineage; Disease Models, Animal; Drug Combinations; Erythropoietin; Female; Fibroblasts; Fibrosis; Kidney; Levodopa; Mice; Mice, Transgenic; Myofibroblasts; Pregnancy

Aristolochic acid (AA) nephropathy, first reported as Chinese herbs nephropathy, is a rapidly progressive tubulointerstitial nephropathy that results in severe anemia, interstitial fibrosis and end-stage renal disease. Tubulointerstitial injury was studied in a mouse model of AA nephropathy to determine whether low-dose darbepoetin alpha (DPO) treatment prevents acute tubular necrosis and interstitial fibrosis.. AA was administered to C3H/He mice intraperitoneally and some mice were also treated with 0.1 microg/kg of DPO weekly starting on the day of AA administration or on day 28. At 28, 56 or 84 days, blood and urine samples were collected and mice were sacrificed for histological assessment of the kidneys.. AA-treated mice developed anemia, elevation of serum creatinine, severe tubular injury similar to acute tubular necrosis and progressive interstitial fibrosis. Although early treatment with low-dose DPO had minimal effects on the hematocrit, it significantly ameliorated acute tubular injury and interstitial inflammation through increasing the survival of tubular cells. As a result, it contributed to preservation of peritubular capillaries and reduction of interstitial fibrosis.. Low-dose DPO treatment conferred protection against acute tubular damage and attenuated interstitial fibrosis in a mouse model of AA nephropathy. Early administration of low-dose DPO may prevent the progression of acute tubular necrosis and the subsequent renal fibrosis in human AA nephropathy.

Topics: Animals; Apoptosis; Aristolochic Acids; Cell Proliferation; Darbepoetin alfa; Disease Models, Animal; Erythropoietin; Fibrosis; Kidney Tubular Necrosis, Acute; Kidney Tubules; Male; Mice; Mice, Inbred C3H

Erythropoiesis-stimulating agents (ESAs) may have therapeutic benefits beyond ameliorating anemia. Although ESAs have renoprotective effects in acute/chronic renal injury models, their effects on blood pressure could also worsen chronic renal failure (CRF). The development of human cell-derived erythropoietin analogue epoetin delta prompted us (1) to investigate whether in a 5/6th nephrectomy-induced CRF rat model, epoetin delta-mediated renoprotective effects occur independently of its hematopoietic effects and (2) to unravel the involvement of particular factors herein.. After induction of CRF in Wistar rats, epoetin delta was administered for 8 weeks at different doses: 0 IU/kg (uremic control); 48, 100 or 300 IU/kg 1x/week, and 16 or 100 IU/kg 3x/week. During this period hematopoietic and renal functional parameters as well as systolic blood pressure (SBP) were monitored.. After 8 weeks, control CRF rats showed reduced hematocrit (Hct)/hemoglobin (Hb) levels and increased SBP. Epoetin delta dose-dependently attenuated the reduction in Hct/Hb. Furthermore, epoetin delta treatment resulted in reduced deterioration of renal function in CRF rats after 8 weeks which was accompanied by decreased collagen deposition, renal fibrosis and interstitial macrophage infiltration. Remarkably, these renoprotective effects did not show the same dose dependency as compared to that seen for the hematopoietic response and were also seen at subhematopoietic doses. Interestingly, epoetin delta treatment resulted in a dose-dependent decrease of profibrotic (TGF-beta) and proapoptotic (Bcl-2-associated X protein) genes together with a significant dose-dependent increase of antifibrotic (hepatocyte growth factor) and antiapoptotic (Bcl-2) genes. Epoetin delta treatment had no effect on VEGF expression.. Epoetin delta treatment could delay the progression of CRF through antiapoptotic and antifibrotic mechanisms. This protective action of epoetin delta on the kidney probably is not directly related to its hematopoietic effects.

Topics: Anemia; Animals; Apoptosis; bcl-2-Associated X Protein; Blood Pressure; Disease Models, Animal; Disease Progression; Erythropoietin; Fibrosis; Hematinics; Hepatocyte Growth Factor; Humans; Kidney; Kidney Failure, Chronic; Male; Nephrectomy; Rats; Rats, Wistar; Recombinant Proteins; Transforming Growth Factor beta

Darbepoetin, a long-acting erythropoietin derivative, attenuates cardiomyocyte apoptosis and improves short-term (3 days) cardiac function, but the mechanisms responsible are unknown. We investigated potential mechanisms by which darbepoetin exerts cardioprotection following myocardial infarction in mice and the significance of the erythropoietin receptor (EPOR)-common beta-chain (c-beta-chain) heteroreceptor.. Mice underwent 60 min coronary occlusion followed by treatment with vehicle or a single dose of darbepoetin. Effects on gene expression, apoptosis and neutrophil accumulation in infarcted left ventricle were assessed 24 h later. Cardiac function, effects on vascularization and fibrosis were assessed 28 days later. The significance of EPOR-c-beta-chain heteroreceptor was examined 28 days after infarction using mice deficient in c-beta-chain.. Twenty-four hours after darbepoetin, mRNAs encoding haeme oxygenase-1 (HO-1), iNOS and brain natriuretic peptide (BNP) were markedly elevated only in infarcted regions, and the frequency of apoptotic cells attenuated. Inflammation was also attenuated with reductions in neutrophil numbers. Darbepoetin also elevated mRNAs encoding angiogenic factors: placental growth factor, monocyte chemoattractant protein-1 and interleukin-1beta. Twenty-eight days after treatment, CD31+ vessels in the infarct zone doubled and fibrosis reduced. Cardiac haemodynamics were improved. Darbepoetin also improved cardiac haemodynamics in c-beta-chain-deficient mice, increased HO-1 and iNOS expression and vessel numbers and attenuated fibrosis.. Darbepoetin stimulates expression of haeme oxygenase, iNOS, BNP and angiogenic factors specifically in infarcted left ventricle that attenuates inflammation, apoptosis and fibrosis; elevate vessel numbers; and improve cardiac function. The EPOR-c-beta-chain heteroreceptor is not essential for these effects.

Topics: Animals; Apoptosis; Cardiotonic Agents; Darbepoetin alfa; Disease Models, Animal; Dose-Response Relationship, Drug; Erythropoietin; Fibrosis; Gene Expression Regulation; Heme Oxygenase-1; Hemodynamics; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardial Infarction; Myocardium; Natriuretic Peptide, Brain; Neovascularization, Physiologic; Neutrophil Infiltration; Nitric Oxide Synthase Type II; Receptors, Erythropoietin; Time Factors; Ventricular Function, Left

Peritoneal dialysis (PD) is an alternative treatment of patients with end-stage renal disease. Unfortunately, long term peritoneal dialysis causes injury of the peritoneum associated with ultra filtration failure. Erythropoietin (EPO) is a potent stimulator of elytroid progenitor cells and its expression is enhanced by hypoxia. The aim of the present study was to evaluate the effect of EPO on the development of experimental peritoneal fibrosis induced by chlorhexidine gluconate (CG). A peritoneal fibrosis model was established using rats treated intraperitoneally with injection of CG. EPO was administered at the dose of 5000 U/kg i.p. three time per week for three weeks. When compared to CG-treated rats, EPO (5000 U/kg i.p. three time per week for three weeks) treated rats subjected to GC-induced peritoneal fibrosis experienced a significantly lower rate in the extent and severity of the histological signs of peritoneal injury. EPO also caused a substantial reduction of (i) the rise in myeloperoxidase activity (mucosa), (ii) the expression in the tissue of TNF-alpha, TGFbeta and VEGF (iii) the increase in staining (immunohistochemistry) for nitrotyrosine and for PAR, as well as (iv) the NF-kappaB activation caused by CG in the peritoneum. Thus, EPO treatment reduces the degree of peritoneal fibrosis caused by CG. We propose that this evidence may help to clarify the potential therapeutic actions of EPO in patients with peritoneal fibrosis.

Topics: Animals; Blotting, Western; Chlorhexidine; Disease Models, Animal; Erythropoietin; Fibrosis; Peritoneal Dialysis; Peritoneal Diseases; Peritoneum; Rats; Rats, Inbred Strains; Thiobarbituric Acid Reactive Substances

We investigated the effect of an erythropoietin (EPO)-gelatin hydrogel drug delivery system (DDS) applied to the heart on myocardial infarct (MI) size, left ventricular (LV) remodelling and function.. Experiments were performed in a rabbit model of MI. The infarct size was reduced, and LV remodelling and function were improved 14 days and 2 months after MI but not at 2 days after MI in the EPO-DDS group. The number of cluster of differentiation 31(CD31)-positive microvessels and the expression of erythropoietin receptor (EPO-R), phosphorylated-Akt (p-Akt), phosphorylated glycogen synthase kinase 3beta (p-GSK-3beta), phosphorylated extracellular signal-regulated protein kinase (p-ERK), phosphorylated signal transducer and activator of transcription 3 (p-Stat3), vascular endothelial growth factor (VEGF), and matrix metalloproteinase-1 (MMP-1) were significantly increased in the myocardium of the EPO-DDS group.. Post-MI treatment with an EPO-DDS improves LV remodelling and function by activating prosurvival signalling, antifibrosis, and angiogenesis without causing any side effect.

Topics: Animals; Blotting, Western; Cardiovascular Agents; Cell Survival; Chemistry, Pharmaceutical; Disease Models, Animal; Dosage Forms; Drug Carriers; Erythropoietin; Fibrosis; Gelatin; Humans; Hydrogels; Immunohistochemistry; Injections, Subcutaneous; Intracellular Signaling Peptides and Proteins; Myocardial Infarction; Myocardium; Neovascularization, Physiologic; Rabbits; Recombinant Proteins; Signal Transduction; Time Factors; Ventricular Function, Left; Ventricular Remodeling

Topics: Erythropoietin; Fibrosis; Humans; Kidney Transplantation; Recombinant Proteins; Skin Diseases

Topics: Acute Kidney Injury; Amlodipine; Epoetin Alfa; Erythropoietin; Female; Fibrosis; Humans; Inflammation; Middle Aged; Prednisone; Recombinant Proteins; Sarcoidosis; Treatment Outcome

We postulated that combining erythropoietin (EPO) infusion with bone marrow mesenchymal stem cells (MSC) delivery may give better prognosis in a rat infarcted heart. Acute myocardial infarction (MI) model was developed by coronary artery ligation. Animals were grouped (n=18) to receive intramyocardial injection of 30 microl saline solution without cells (EPO and control groups) or with 3x10(6) MSC from transgenic green fluorescent protein (GFP)+ male mice (MSC and MSC-EPO groups). The animals received either 5000 U/kg body weight EPO (EPO and MSC-EPO groups) or saline solution (MSC and control groups) for 7 days after MI. Cardiac functions were measured by echocardiography and cardiac tissue was harvested for immunohistological studies 3 weeks after surgery. We observed regeneration of MSC in and around the infarcted myocardium in MSC and MSC-EPO groups. Capillary density was markedly enhanced with significantly smaller infarct size and reduced fibrotic area in MSC-EPO group as compared with other three groups. A smaller left ventricular (LV) diastolic dimension and a higher LV fractional shortening were observed in MSC-EPO group than in other three groups. Transplantation of MSC combined with cytokine EPO is superior to either of the monotherapy approach for angiomyogenesis and cardiac function recovery.

Topics: Animals; Bone Marrow Transplantation; Capillaries; Cell Differentiation; Cells, Cultured; Combined Modality Therapy; Echocardiography; Erythropoietin; Female; Fibrosis; Injections, Intralesional; Male; Mesenchymal Stem Cell Transplantation; Mice; Myocardial Infarction; Neovascularization, Physiologic; Rats; Rats, Wistar

Topics: Erythropoietin; Fibrosis; Gadolinium; Humans; Recombinant Proteins; Renal Insufficiency; Skin Diseases

The inhibitory effects of recombinant human erythropoietin (rhEPO) were examined against (1) the progression of renal fibrosis in mice with complete unilateral ureteral obstruction and (2) the TGF-beta1-induced epithelial-to-mesenchymal transition (EMT) in MDCK cells. Unilateral ureteral obstruction was induced in BALB/c mice and rhEPO (100 or 1000 U/kg, intraperitoneally, every other day) or vehicle was administered from day 3 to day 14. Immunoblotting and immunohistochemistry revealed increased expressions of TGF-beta1, alpha-smooth muscle actin (alpha-SMA), and fibronectin and decreased expression of E-cadherin in the obstructed kidneys. In contrast, rhEPO treatment significantly attenuated the upregulation of TGF-beta1 and alpha-SMA and the downregulation of E-cadherin. MDCK cells were treated with TGF-beta1 (5 ng/ml) for 48 h to induce EMT, and the cells were then co-treated with TGF-beta1 and rhEPO for another 48 h. Increased expressions of alpha-SMA and vimentin and decreased expressions of zona occludens-1 and E-cadherin were observed after TGF-beta1 treatment, and these changes were markedly attenuated by rhEPO co-treatment. TGF-beta1 increased phosphorylated Smad-2 expression in MDCK cells, which was decreased by rhEPO co-treatment. In conclusion, rhEPO treatment inhibits the progression of renal fibrosis in obstructed kidney and attenuates the TGF-beta1-induced EMT. It is suggested that the renoprotective effects of rhEPO could be mediated, at least partly, by inhibition of TGF-beta1-induced EMT.

Topics: Actins; Animals; Cells, Cultured; Disease Progression; Dogs; Epithelial Cells; Erythropoietin; Fibronectins; Fibrosis; Humans; Kidney; Kidney Diseases; Male; Mesoderm; Mice; Mice, Inbred BALB C; Recombinant Proteins; Transforming Growth Factor beta1; Ureteral Obstruction

Nephrogenic systemic fibrosis is a rare fibrosing condition that occurs in patients with renal insufficiency. While its histologic characteristics have been well described, the etiology and pathogenesis have not been fully characterized. Several recent studies support the theory that gadolinium-based contrast agents play a causative role in the development of the disease. Erythropoietin therapy and endothelial damage from surgical procedures have also been suggested as potential contributing factors.. This study attempts to help contribute to the understanding of this novel disorder.. We performed a retrospective chart review of 6 patients diagnosed with nephrogenic systemic fibrosis at our institution. Emphasis was placed on identification of potential putative etiologic agents including gadolinium, erythropoietin therapy, and previous surgical procedures.. All patients had documented exposure to gadolinium-based contrast agents. Three of the 6 patients were treated with erythropoietin, and all patients underwent a previous surgical procedure.. This study is limited by its small size; therefore, the findings and results may not be applicable to all patients with this disorder.. Our data suggest that gadolinium plays a primary role in nephrogenic systemic fibrosis and that prior surgery may be a contributory factor.

Topics: Adult; Aged; Contrast Media; Erythropoietin; Female; Fibrosis; Gadolinium; Humans; Male; Middle Aged; Renal Dialysis; Renal Insufficiency; Retrospective Studies; Skin Diseases; Surgical Procedures, Operative

Topics: Adult; Case-Control Studies; Drug Interactions; Erythropoietin; Female; Fibrosis; Gadolinium; Hematinics; Humans; Kidney Failure, Chronic; Male; Middle Aged; Radiopharmaceuticals; Recombinant Proteins; Risk Factors; Skin; Skin Diseases

Identification of isolated congenital heart block (CHB) predicts, with near certainty, the presence of maternal anti-SSA/Ro antibodies; however, the 2% incidence of CHB in first offspring of anti-SSA/Ro+ mothers, 20% recurrence in subsequent pregnancies, and discordance in identical twins suggest that an environmental factor amplifies the effect of the antibody. Accordingly, this study was carried out to explore the hypothesis that hypoxia potentiates a profibrosing phenotype of the fetal cardiac fibroblast.. Evidence of an effect of hypoxia was sought by immunohistologic evaluation of CHB-affected fetal heart tissue and by determination of erythropoietin levels in cord blood. The in vitro effect of hypoxia on gene expression and phenotype in fibroblasts derived from fetal hearts and lungs was investigated by Affymetrix arrays, quantitative polymerase chain reaction (PCR), immunofluorescence, and immunoblotting.. In vivo hypoxic exposure was supported by the prominent intracellular fibroblast expression of hypoxia-inducible factor 1alpha in conduction tissue from 2 fetuses in whom CHB led to death. The possibility that hypoxia was sustained was suggested by significantly elevated erythropoietin levels in cord blood from CHB-affected, as compared with unaffected, anti-SSA/Ro-exposed neonates. In vitro exposure of cardiac fibroblasts to hypoxia resulted in transdifferentiation to myofibroblasts (a scarring phenotype), as demonstrated on immunoblots and immunofluorescence by increased expression of smooth muscle actin (SMA), an effect not seen in lung fibroblasts. Hypoxia-exposed cardiac fibroblasts expressed adrenomedullin at 4-fold increased levels, as determined by Affymetrix array, quantitative PCR, and immunofluorescence, thus focusing attention on cAMP as a modulator of fibrosis. MDL12,330A, an adenylate cyclase inhibitor that lowers the levels of cAMP, increased expression of fibrosis-related proteins (mammalian target of rapamycin, SMA, plasminogen activator inhibitor type 1, and type I collagen), while the cAMP activator forskolin attenuated transforming growth factor beta-elicited fibrosing end points in the cardiac fibroblasts.. These findings provide evidence that hypoxia may amplify the injurious effects of anti-SSA/Ro antibodies. Modulation of cAMP may be a key component in the scarring phenotype. Further assessment of the susceptibility of cardiac fibroblasts to cAMP modulation offers a new research direction in CHB.

Topics: Actins; Adrenomedullin; Antibodies, Antinuclear; Autoimmunity; Cell Hypoxia; Cell Transdifferentiation; Cells, Cultured; Cyclic AMP; Disease Progression; Erythropoietin; Fibroblasts; Fibrosis; Heart; Heart Block; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Lung; RNA, Messenger; Transforming Growth Factor beta

Topics: Erythropoietin; Fibrosis; Humans; Recombinant Proteins; Renal Insufficiency; Skin Diseases

The JAK2(V617F) mutation is present in almost all patients with polycythemia vera (PV), large proportions of patients with essential thrombocythemia and idiopathic myelofibrosis, and less frequently in atypical myeloproliferative disorders (MPD). We show that transplantation of JAK2(V617F)-transduced bone marrow into BALB/c mice induces MPD reminiscent of human PV, characterized by erythrocytosis, granulocytosis, extramedullary hematopoiesis, and bone marrow fibrosis, but not thrombocytosis. Fluorescence-activated cell sorting of bone marrow and spleen showed proportional expansion of common myeloid progenitors, granulocyte-monocyte and megakaryocyte-erythrocyte progenitors. Megakaryocyte and late erythroid progenitors were dramatically increased, with only modest expansion of early erythroid progenitors. Erythropoietin (Epo) receptor expression was reduced on early, but normal on late erythroblasts. Serum levels of Epo and granulocyte colony-stimulating factor, but not granulocyte macrophage colony-stimulating factor, were reduced, whereas tumor necrosis factor-alpha was increased, possibly exerting a negative effect on JAK2(V617F)-negative hematopoiesis. These data suggest that erythrocytosis and granulocytosis in JAK2(V617F) mice are the net result of a complex interplay between cell intrinsic and extrinsic factors. There were no thromboembolic events and no animals succumbed to their disease, implicating additional factors in the manifestation of human disease. The disease was not transplantable and prolonged observation showed normalization of blood counts in most JAK2(V617F) mice, suggesting that the mutation may not confer self-renewal capacity.

Topics: Animals; Bone Marrow; Bone Marrow Cells; Bone Marrow Transplantation; Cell Line; Clone Cells; Erythropoietin; Fibrosis; Granulocyte Colony-Stimulating Factor; Hematopoiesis, Extramedullary; Hematopoietic Stem Cells; Humans; Janus Kinase 2; Mice; Mice, Inbred BALB C; Mutation, Missense; Myeloproliferative Disorders; Polycythemia; Polycythemia Vera; Receptors, Erythropoietin; Spleen; Time Factors; Transfection; Tumor Necrosis Factor-alpha

Pulmonary oxygen toxicity is believed to play a prominent role in the lung injury that leads to the development of bronchopulmonary dysplasia (BPD). To determine whether human recombinant erythropoietin (rhEPO) treatment reduces the risk of developing BPD, we investigated the effect of rhEPO treatment on the histopathologic changes seen in hyperoxia-induced lung injury of BPD. Twenty-five rat pups were divided into four groups: air-exposed control group (n = 5), hyperoxia-exposed placebo group (n = 7), hyperoxia-exposed rhEPO-treated group (n = 6), and air-exposed rhEPO-treated group (n = 7). Measurement of alveolar surface area, quantification of secondary crest formation, microvessel count, evaluation of alveolar septal fibrosis, and smooth muscle actin immunostaining were performed to assess hyperoxia-induced changes in lung morphology. Treatment of hyperoxia-exposed animals with rhEPO resulted in a significant increase in the mean alveolar area, number of secondary crests formed, and the microvessel count in comparison with hyperoxia-exposed placebo-treated animals. There was significantly less fibrosis in rhEPO-treated animals. However, treatment of hyperoxia-exposed animals with rhEPO did not result in a significant change in smooth muscle content compared with hyperoxia-exposed placebo treated animals. Our results suggest treatment with rhEPO during hyperoxia exposure is associated with improved alveolar structure, enhanced vascularity, and decreased fibrosis. Therefore, we conclude that treatment of preterm infants with EPO might reduce the risk of developing BPD.

Topics: Animals; Animals, Newborn; Body Weight; Erythropoietin; Fibrosis; Hypoxia; Immunohistochemistry; Lung; Lung Injury; Microcirculation; Neovascularization, Pathologic; Oxygen; Pulmonary Alveoli; Rats; Rats, Wistar; Recombinant Proteins

Hepatitis C virus (HCV) recurrence is a serious problem after orthotopic liver transplantation (OLT). The role of ribavirin as a single agent to treat recurrent HCV is controversial. Our aim was to evaluate the correlation between alanine aminotransferase (ALT) levels and histological findings in OLT recipients treated with ribavirin monotherapy for recurrent HCV. The mean [+/- standard error (SE)] age of 11 patients was 50.1 (SE +/- 8.6) years. The estimated mean dose and duration of ribavirin treatment (+/- SE) was 661.5 (+/- 52.5) mg and 20.4 (+/- 1.7) months, respectively. Five patients required either dose reduction or erythropoietin. We found a significant decrease of mean (+/- SE) ALT value from 246 +/- 44.8 U/L to 109.4 +/- 49.1 U/L (p = 0.002) in patients treated with ribavirin. However, there was also significant worsening of interface activity (p = 0.03) and fibrosis (p = 0.02). No significant association was found between ALT values and (i) stage of hepatic fibrosis, (ii) interface activity, (iii) lobular activity and (iv) HCV RNA values. Our results suggest that HCV disease can progress despite a significant decrease in ALT values. ALT values are inadequate markers of the ribavirin monotherapy and can lead to erroneous conclusions of efficacy.

Topics: Adult; Aged; Alanine Transaminase; Antiviral Agents; Erythropoietin; Female; Fibrosis; Hepacivirus; Hepatitis C; Humans; Liver Transplantation; Male; Middle Aged; Recurrence; Ribavirin; Time Factors

Recombinant human erythropoietin (rhEPO) was administered intravenously to Beagle dogs in daily doses of 100, 500 and 3000 units/kg/day for 3 months. The high dose was more than 200-fold the therapeutic human maintenance dose. Such excessive rhEPO doses elicited extreme erythropoiesis. There was a dose-dependent stimulation of bone marrow fibroblasts, leading to bone marrow fibrosis in some of the high dose animals. The extent of myelofibrosis was intra- and interindividually different in various bones. Sternebrae proved to be practical for morphometric studies. The point-counting method was used for measurement. The portion of fatty tissue, sinusoids and fibrous tissue in the medullary space as well as the number of blood vessels and megakaryocytes were calculated. Such experimental conditions are not of relevance in human patients whose rhEPO therapy is interrupted as soon as their PCV reaches 35 vol%. Experimentally induced myelofibrosis should therefore not be considered as a risk in patients receiving therapeutic doses of rhEPO.

Topics: Adipose Tissue; Animals; Bone Marrow; Dogs; Dose-Response Relationship, Drug; Erythropoiesis; Erythropoietin; Fibroblasts; Fibrosis; Image Processing, Computer-Assisted; Injections, Intravenous; Recombinant Proteins