transforming-growth-factor-beta and Cardio-Renal-Syndrome

In recent years, there has been considerable interest in cellular and tissue responses to injury that result in the deposition of extracellular matrix, collagen, elastic fibers, and the histopathological development of fibrosis. In the myocardium, fibrosis results in many recognizable clinical features, including PR interval prolongation, heart block, bundle branch block, left ventricular dyssynergy, anisotropy, atrial fibrillation, ventricular arrhythmias, systolic and diastolic dysfunction, heart failure, and cardiac death. In the kidneys, fibrosis in the glomerulus leads to glomerular sclerosis, and in the inner cortex and medulla, tubulointerstitial fibrosis leads to a reduction in renal filtration function and rapidly progressive chronic kidney disease. There are a great number of potential early mediators of cellular damage in response to events such as ischemia, neurohormonal activation, biomechanical stretch, and abnormal cell signaling. However, many studies suggest that interstitial cells in both organs, including macrophages, T lymphocytes, fibroblasts, and myofibroblasts, have common communication systems that utilize galectin-3 and transforming growth factor-β that result in the upregulation and proliferation of fibroblasts and myofibroblasts, which produce and secrete procollagen I. Procollagen I cross-links in the extracellular space to form mature collagen, which is a fundamental unit of organ fibrosis. Future research will be concentrating on the pathogenic mechanisms that turn on fibrosis and on therapeutic targets that can either prevent the activation of fibroblasts or limit their repair response to injury.

Topics: Acute Kidney Injury; Animals; Cardio-Renal Syndrome; Chronic Disease; Collagen Type I; Extracellular Matrix; Fibrosis; Galectin 3; Heart; Heart Failure; Humans; Inflammation; Interleukin-1 Receptor-Like 1 Protein; Kidney; Models, Biological; Myocardium; Myofibroblasts; Natriuretic Agents; Receptors, Cell Surface; Stress, Mechanical; Transforming Growth Factor beta

BACKGROUNDCardiorenal syndrome (CRS) - renal injury during heart failure (HF) - is linked to high morbidity. Whether circulating extracellular vesicles (EVs) and their RNA cargo directly impact its pathogenesis remains unclear.METHODSWe investigated the role of circulating EVs from patients with CRS on renal epithelial/endothelial cells using a microfluidic kidney-on-chip (KOC) model. The small RNA cargo of circulating EVs was regressed against serum creatinine to prioritize subsets of functionally relevant EV-miRNAs and their mRNA targets investigated using in silico pathway analysis, human genetics, and interrogation of expression in the KOC model and in renal tissue. The functional effects of EV-RNAs on kidney epithelial cells were experimentally validated.RESULTSRenal epithelial and endothelial cells in the KOC model exhibited uptake of EVs from patients with HF. HF-CRS EVs led to higher expression of renal injury markers (IL18, LCN2, HAVCR1) relative to non-CRS EVs. A total of 15 EV-miRNAs were associated with creatinine, targeting 1,143 gene targets specifying pathways relevant to renal injury, including TGF-β and AMPK signaling. We observed directionally consistent changes in the expression of TGF-β pathway members (BMP6, FST, TIMP3) in the KOC model exposed to CRS EVs, which were validated in epithelial cells treated with corresponding inhibitors and mimics of miRNAs. A similar trend was observed in renal tissue with kidney injury. Mendelian randomization suggested a role for FST in renal function.CONCLUSIONPlasma EVs in patients with CRS elicit adverse transcriptional and phenotypic responses in a KOC model by regulating biologically relevant pathways, suggesting a role for EVs in CRS.TRIAL REGISTRATIONClinicalTrials.gov NCT03345446.FUNDINGAmerican Heart Association (AHA) (SFRN16SFRN31280008); National Heart, Lung, and Blood Institute (1R35HL150807-01); National Center for Advancing Translational Sciences (UH3 TR002878); and AHA (23CDA1045944).

Topics: Cardio-Renal Syndrome; Endothelial Cells; Extracellular Vesicles; Heart Failure; Humans; Kidney; MicroRNAs; Transforming Growth Factor beta

Cardiorenal syndrome is defined by primary heart failure conditions influencing or leading to renal injury or dysfunction. Dilated cardiomyopathy (DCM) is a major co-existing form of heart failure (HF) with renal diseases. Myocardin (MYOCD), a cardiac-specific co-activator of serum response factor (SRF), is increased in DCM porcine and patient cardiac tissues and plays a crucial role in the pathophysiology of DCM. Inhibiting the increased MYOCD has shown to be partially rescuing the DCM phenotype in porcine model. However, expression levels of MYOCD in the cardiac tissues of the cardiorenal syndromic patients and the effect of inhibiting MYOCD in a cardiorenal syndrome model remains to be explored. Here, we analyzed the expression levels of MYOCD in the DCM patients with and without renal diseases. We also explored, whether cardiac specific silencing of MYOCD expression could ameliorate the cardiac remodeling and improve cardiac function in a renal artery ligated rat model (RAL). We observed an increase in MYOCD levels in the endomyocardial biopsies of DCM patients associated with renal failure compared to DCM alone. Silencing of MYOCD in RAL rats by a cardiac homing peptide conjugated MYOCD siRNA resulted in attenuation of cardiac hypertrophy, fibrosis and restoration of the left ventricular functions. Our data suggest hyper-activation of MYOCD in the pathogenesis of the cardiorenal failure cases. Also, MYOCD silencing showed beneficial effects by rescuing cardiac hypertrophy, fibrosis, size and function in a cardiorenal rat model.

Topics: Angiotensin II; Animals; Cardio-Renal Syndrome; Cardiomyopathy, Dilated; Collagen Type I; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Fibroblasts; Fibrosis; Heart Ventricles; Male; Myocytes, Cardiac; Nuclear Proteins; Rats; RNA Interference; RNA, Small Interfering; Trans-Activators; Transforming Growth Factor beta; Ventricular Function

Increased endoplasmic reticulum (ER) stress contributes to development of cardiorenal syndrome (CRS), and Silent Information Regulator 1 (SIRT1), a class III histone deacetylase, may have protective effects on heart and renal disease, by reducing ER stress. We aimed to determine if SIRT1 alleviates CRS through ER stress reduction.. Wild type mice (n=37), mice with cardiac-specific SIRT1 knockout (n=29), or overexpression (n=29), and corresponding controls, were randomized into four groups: sham MI (myocardial infarction) +sham STNx (subtotal nephrectomy); MI+sham STNx; sham MI+STNx; and MI+STNx. To establish the CRS model, subtotal nephrectomy (5/6 nephrectomy, SNTx) and myocardial infarction (MI) (induced by ligation of the left anterior descending (LAD) coronary artery) were performed successively to establish CRS model. At week 8, the mice were sacrificed after sequential echocardiographic and hemodynamic studies, and then pathology and Western-blot analysis were performed.. Neither MI nor STNx alone significantly influenced the other healthy organ. However, in MI groups, STNx led to more severe cardiac structural and functional deterioration, with increased remodeling, increased BNP levels, and decreased EF, Max +dp/dt, and Max -dp/dt values than in sham MI +STNx groups. Conversely, in STNx groups, MI led to renal structural and functional deterioration, with more severe morphologic changes, augmented desmin and decreased nephrin expression, and increased BUN, SCr and UCAR levels. In MI+STNx groups, SIRT1 knockout led to more severe cardiac structural and functional deterioration, with higher Masson-staining score and BNP levels, and lower EF, FS, Max +dp/dt, and Max -dp/dt values; while SIRT1 overexpression had the opposite attenuating effects. In kidney, SIRT1 knockout resulted in greater structural and functional deterioration, as evidenced by more severe morphologic changes, higher levels of UACR, BUN and SCr, and increased desmin and TGF-β expression, while SIRT1 overexpression resulted in less severe morphologic changes and increased nephrin expression without significant influence on BUN or SCr levels. The SIRT1 knockout but not overexpression resulted in increased myocardial expression of CHOP and GRP78. Cardiac-specific SIRT1 knockout or overexpression resulted in increased or decreased renal expression of CHOP, Bax, and p53 respectively.. Myocardial SIRT1 activation appears protective to both heart and kidney in CRS models, probably through modulation of ER stress.

Topics: Animals; Cardio-Renal Syndrome; Creatinine; Desmin; Disease Models, Animal; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Heart; Kidney; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardial Infarction; Myocardium; Nephrectomy; Sirtuin 1; Transcription Factor CHOP; Transforming Growth Factor beta

In cardiorenal syndrome (CRS) type 2, chronic heart failure (HF) results in the onset or progression of chronic kidney disease (CKD). Examples of CRS type 2 (CRS2) include progressive CKD resulting from chronic HF in congenital or acquired heart disease or from repeated bouts of acute decompensated HF. Animal data and clinical studies indicate that extended periods of chronic HF result in altered renal hemodynamics followed by progressive renal pathology. Experimental and clinical data indicate that CRS2 is characterized by mild to moderate proteinuria, a progressive decline of glomerular filtration rate, and an elevated expression of renal injury biomarkers. Important pathophysiological triggers of renal disease progression include chronic increases in renal venous pressure, maladaptive activation of the renin-angiotensin-aldosterone axis and the sympathetic nervous system, as well as a chronic inflammatory state. Intrarenal oxidative stress and proinflammatory signaling precipitate structural injury, including glomerulosclerosis and tubulointerstitial fibrosis. Yet, clinical interventional trials that directly test the impact of renin-angiotensin system antagonists and β-blockers on the progression of CKD in CRS2 are lacking. Secondary analyses of trials designed to assess the impact of these agents on cardiovascular endpoints have failed to show a consistent benefit regarding renal functional parameters. In contrast, left ventricular assist device placement and cardiac resynchronization therapy in HF patients consistently improved renal function, suggesting a marked potential for reversibility in many cases of CRS2. Future research should be directed towards the evaluation of novel biomarkers to improve the diagnosis, severity grading as well as our understanding of the pathophysiology of CRS2. In addition, there is a need for interventional trials in HF patients to address long-term renal endpoints incorporating clinical information and measures of renal function as well as renal injury.

Topics: Acute-Phase Proteins; Animals; Biomarkers; Cardio-Renal Syndrome; Chronic Disease; Disease Models, Animal; Heart Failure; Humans; Lipocalin-2; Lipocalins; Proto-Oncogene Proteins; Renin-Angiotensin System; Sympathetic Nervous System; Transforming Growth Factor beta

Progressive decline in renal function coexists with myocardial infarction (MI); however, little is known about its pathophysiology. This study aimed to systematically identify post-MI renal changes (functional, histological, and molecular) over time in a rat MI model and examine potential mechanisms that may underlie these changes. Rats were randomized into three groups: nonoperated, sham, and MI. Cardiac and renal function was assessed before death at 1, 4, 8, 12, and 16 wk with tissues collected for histological, protein, and gene studies. Tail-cuff blood pressure was lower in MI than sham and nonoperated animals only at 1 wk (P < 0.05). Systolic function was reduced (P < 0.0001) while heart/body weight and left ventricle/body weight were significantly greater in MI animals at all time points. Glomerular filtration rate decreased following MI at 1 and 4 wk (P < 0.05) but not at 8 and 12 wk and then deteriorated further at 16 wk (P = 0.052). Increased IL-6 gene and transforming growth factor (TGF)-β protein expression as well as macrophage infiltration in kidney cortex was detected at 1 wk (P < 0.05). Renal cortical interstitial fibrosis was significantly greater in MI animals from 4 wk, while TGF-β bioactivity (phospho-Smad2) was upregulated at all time points. The degree of fibrosis increased and was maximal at 16 wk. In addition, kidney injury molecule-1-positive staining in the tubules was more prominent in MI animals, maximal at 1 wk. In conclusion, renal impairment occurs early post-MI and is associated with hemodynamic and structural changes in the kidney possibly via activation of the Smad2 signaling pathway.

Topics: Animals; Biomarkers; Cardio-Renal Syndrome; Cell Adhesion Molecules; Disease Models, Animal; Fibrosis; Glomerular Filtration Rate; Hemodynamics; Interleukin-6; Kidney; Male; Myocardial Infarction; Rats; Rats, Sprague-Dawley; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta