mycophenolic-acid and Reperfusion-Injury

Liver transplantation has been widely accepted as an effective intervention for end-stage liver diseases and early hepatocellular carcinomas. However, a variety of postoperative complications and adverse reactions have baffled medical staff and patients. Currently, transplantation monitoring relies primarily on nonspecific biochemical tests, whereas diagnosis of multiple complications depends on invasive pathological examination. Therefore, a noninvasive monitoring method with high selectivity and specificity is desperately needed. This review summarized the potential of endogenous small-molecule metabolites as biomarkers for assessing graft function, ischemia-reperfusion injury and liver rejection. Exogenous metabolites, mainly those immunosuppressive agents with high intra- and inter-individual variability, were also discussed for transplantation monitoring.

Topics: Biomarkers; Carcinoma, Hepatocellular; Everolimus; Graft Rejection; Humans; Immunosuppressive Agents; Liver Neoplasms; Liver Transplantation; Metabolome; Mycophenolic Acid; Postoperative Complications; Prognosis; Reperfusion Injury; Tacrolimus

This review summarizes the focus shift from ischemia-reperfusion injury and avoidance of rejection to long-term outcome after pediatric renal transplantation over the past decade. Although there has been excellent 1-year graft and patient survival, low rejection rates can be achieved with modern immunosuppression after pediatric renal transplantation, and patient survival is improved substantially in comparison with dialysis, pediatric renal transplant recipients experience a high prevalence of infections, malignancies, medication side effects, nonadherence, and, most importantly, cardiovascular morbidity and mortality. Additional challenges occur because of a high prevalence of obesity after transplantation and vascular calcifications. There is also in an underappreciation of chronic kidney disease (CKD) in transplant recipients. The etiology of CKD is multifactorial and can affect graft and patient survival. The rigors of treatment for CKD are less compared with CKD in nontransplant recipients. Almost all immunosuppressive drugs are implicated with a risk of hypertension, hyperlipidemia, and diabetogenicity, all of which contribute to cardiovascular morbidity. Corticosteroids exhibit the most substantial risk and also stunt growth. Effective new treatment protocols such as the recent European Tacrolimus and WIthdrawal of STeroids (TWIST) study with rapid steroid withdrawal after 5 days provide promising results without increasing the rejection risk. The shift in focus on long-term complications allows for improved graft outcome. Side effects of immunosuppressive medications require continued attention to further improve long-term outcomes.

Topics: Child; Graft Rejection; Humans; Hypertension; Immunosuppression Therapy; Immunosuppressive Agents; Kidney Failure, Chronic; Kidney Transplantation; Mycophenolic Acid; Reperfusion Injury

Mycophenolate mofetil (MMF), an immunosuppressive drug, exerts anti-inflammatory effects on organs during ischemia/reperfusion (I/R) injury. However, the exact function of MMF in hepatic I/R injury remains largely unknown. The purpose of this study was to explore the role and potential mechanism of MMF protection in hepatic I/R injury.. Male wild type (WT) and TLR4 knockout (KO) mice were injected intraperitoneally with MMF or normal saline. Animals underwent 90 min of partial hepatic ischemia, followed by 1, 6, or 24 h of reperfusion. Hepatic histology, serum amiotransferase, inflammatory cytokines, hepatocyte apoptosis, and hepatocyte autophagy were examined to assess liver injury.. Treatment with MMF significantly decreased hepatic I/R injury as indicated by a reduction in serum aminotransferase levels, Suzuki scores, and the overall degree of necrosis. MMF treatment inhibited TLR4 activation dramatically. MMF administration also significantly inhibited the activation of the NF-κB pathway and the expression of pro-inflammatory cytokines. In TLR4 KO mice, MMF still exerted protection from hepatic I/R injury. MMF treatment inhibited hepatocyte apoptosis, as indicated by reduced TUNEL staining, and reduced the accumulation of cleaved caspase-3. In addition, MMF may induce autophagy and increase autophagic flux before and after hepatic reperfusion by augmenting the expression of LC3-II, P62, and Beclin-1. The induction of autophagy by MMF treatment may be related to TLR4 activation.. Our results indicate that MMF treatment ameliorates hepatic I/R injury. The mechanism of action likely involves the ability of MMF to decrease apoptosis and the inflammatory response while inducing autophagy.

Topics: Animals; Apoptosis; Liver; Male; Mice; Mice, Knockout; Mycophenolic Acid; Reperfusion Injury; Signal Transduction; Toll-Like Receptor 4

Tacrolimus and mycophenolate mofetil are immunosuppressive agents widely used on the postoperative period of the transplants.. To evaluate the influence of the association of them on the abdominal wall healing in rats.. Thirty-six Wistar rats were randomly assigned in three groups of 12. On the early postoperative period, four of the control group and three of the experimental groups died. The three groups were nominated as follow: control group (GC, n=8); group I (GI, n=11, standard operation, mycophenolate mofetil and tacrolimus); group II (GII, n=10, standard operation, mycophenolate mofetil and tacrolimus). The standard operation consisted of right total nephrectomy and 20 min ischemia of the left kidney followed by reperfusion. Both NaCl 0.9% and the immunosuppressive agents were administered starting on the first postoperative day and continuing daily until the day of death on the 14th day. On the day of their deaths, two strips of the anterior abdominal wall were collected and submitted to breaking strength measurement and histological examination.. There were no significant differences in wound infection rates (p=0,175), in the breaking strength measurement and in the histological examination among the three groups.. The combination of the immunosuppressive agents used in the study associated with renal ischemia and reperfusion does not interfere in the abdominal wall healing of rats.

Topics: Abdominal Wall; Animals; Immunosuppressive Agents; Ischemia; Kidney; Mycophenolic Acid; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury; Tacrolimus

Ischaemia/reperfusion (I/R) is one of the main causes of acute kidney injury (AKI), which is characterized by sterile inflammation and oxidative stress. Immune cell activation can provoke overproduction of inflammatory mediators and reactive oxygen species (ROS), leading to perturbation of the microcirculation and tissue oxygenation associated with local and remote tissue injury. This study investigated whether the clinically employed immunosuppressant mycophenolate mofetil (MMF) was able to reduce I/R-induced renal oxygenation defects and oxidative stress by preventing sterile inflammation. Rats were divided into three groups (n=6/group): (1) a sham-operated control group; (2) a group subjected to renal I/R alone (I/R); and (3) a group subjected to I/R and MMF treatment (20 mg/kg prior to I/R) (I/R+MMF). Ischaemia was induced by a vascular occluder placed on the abdominal aorta for 30 minutes, followed by 120 minutes of reperfusion. Renal I/R deteriorated renal oxygenation (P<.001) and oxygen delivery (P<.01), reduced creatinine clearance (P<.01) and tubular sodium reabsorption (P<.001), and increased iNOS, renal tissue injury markers (P<.001), and IL-6 (P<.001). Oral MMF administration prior to insult restored renal cortical oxygenation (P<.05) and iNOS, renal injury markers, and inflammation parameters (P<.001) to near-baseline levels without affecting renal function. MMF exerted a prophylactic effect on renal microvascular oxygenation and abrogated tissue inflammation and renal injury following lower body I/R-induced AKI. These findings may have clinical implications during major vascular or renal transplant surgery.

Topics: Acute Kidney Injury; Animals; Aorta, Abdominal; Disease Models, Animal; Hemodynamics; Immunosuppressive Agents; Ischemia; Kidney; Male; Microcirculation; Microvessels; Mycophenolic Acid; Oxygen Consumption; Rats, Wistar; Renal Circulation; Reperfusion Injury

This study evaluated the effect of mycophenolate mofetil (MMF) on uterine tissue preservation following ischaemia/reperfusion (I/R) injury. Uterine I/R injury was induced in rats by clamping the lower abdominal aorta and ovarian arteries for 30 min. Group I/R + V (n = 7) received vehicle alone while Group I/R + M (n = 7) received 20 mg/kg/day MMF. Control groups underwent sham surgery and received vehicle (Group C) or 20 mg/kg/day MMF (Group M) (n = 7 for both). Four hours after detorsion, uterine tissue 8-hydroxy-2'-deoxyguanosine (8-OHdG), glutathione, malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD) and serum ischaemia modified albumin (IMA) concentrations were measured. Histopathological analyses were performed. The I/R + M group showed significant reduction in serum IMA and uterine tissue 8-OHdG, MDA and MPO and significant increase in SOD concentrations compared with the I/R + V group, indicating a protective effect against I/R oxidative damage (P = 0.009, P = 0.006, P = 0.002, P = 0.003 and P = 0.009, respectively). Histopathological evaluation revealed MMF treatment resulted in significantly less tissue and cellular damage and apoptosis compared with the I/R + V group. These results indicate MMF is effective in attenuating uterine tissue damage and preventing apoptosis following uterine I/R injury, probably via anti-inflammatory and anti-oxidative action.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Albumins; Animals; Antibiotics, Antineoplastic; Antioxidants; Aorta, Abdominal; Arteries; Deoxyguanosine; Disease Models, Animal; Female; Glutathione; Immunosuppressive Agents; Mycophenolic Acid; Ovary; Peroxidase; Rats; Rats, Wistar; Reperfusion Injury; Superoxide Dismutase; Uterus

To evaluate renal histological changes and renal function in single kidney rats submitted to renal ischemia-reperfusion and to immunosuppression with tacrolimus and mycophenolate-mofetil.. Experimental study with 80 Wistar rats distributed into control, Sham and six other groups treated with immunosuppressive drugs. Animals undergoing surgery, right nephrectomy and left renal clamping, killed on the 14th day and analyzed for renal histology, urea and creatinine.. The group receiving tacrolimus at higher doses (T3) showed renal histological lesions indicative of early nephrotoxicity, and significant increase in urea and creatinine. The group M (mycophenolate-mofetil alone) and the group M2 (mycophenolate-mofetil combined with half the usual dose of tacrolimus) presented a slight rise in serum urea. The groups using mycophenolate-mofetil alone or combined with tacrolimus showed creatinine levels similar to that of the group T3.. Histologically, the association of injury by ischemia-reperfusion with the use of tacrolimus or mycophenolate-mofetil alone demonstrated a higher rate of renal changes typical of early nephrotoxicity. In laboratory, the combination of injury by ischemia-reperfusion with tacrolimus at higher doses proved to be nephrotoxic.

Topics: Animals; Calcineurin Inhibitors; Creatinine; Immunosuppression Therapy; Immunosuppressive Agents; Ischemia; Kidney; Kidney Diseases; Male; Mycophenolic Acid; Nephrons; Random Allocation; Rats, Wistar; Reperfusion Injury; Tacrolimus; Time Factors; Urea

Renal ischemia/reperfusion (I/R) injury causes high mortality and morbidity during renal procedures, yet current drugs should be used at high doses or for long periods due to lack of tissue specificity. In previous work we described a novel mycophenolic acid-glucosamine conjugate (MGC) that targets the proximal tubule epithelium, where it efficiently reduces renal I/R injury in rats and promotes recovery from reperfusion. Here we perform mechanistic studies of MGC in rats that suggest that the conjugate works by repressing the activation of renal inosine-5'-monophosphate dehydrogenase 2 (IMPDH2), thereby inhibiting the proliferation and accumulation of lympholeukocytes in the proximal tubules. In addition, MGC appears to inhibit inflammation through various pathways, including inhibition of free oxygen radical production, upregulation of bone morphogenetic protein-7, and downregulation of complement protein 3, TLR 4, intracellular adhesion molecules in the endothelium, proinflammatory cytokines (e.g., TNF-α, IL-6, IL-1, TGF-β), and chemotactic cytokines [e.g., monocyte chemoattractant protein-1 (MCP-1) and IL-8]. These findings suggest that MGC specifically targets the proximal tubules and acts through numerous mechanisms to substantially mitigate I/R injury in rats; this conjugate may provide a more effective alternative to current combination therapy.

Topics: Animals; Anti-Inflammatory Agents; Glucosamine; IMP Dehydrogenase; Interleukin-6; Kidney; Male; Mycophenolic Acid; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tumor Necrosis Factor-alpha

Mycophenolate mofetil (MMF) has been used to prevent transplant rejection for many years and has been shown to have protective effects against renal failure. The objective was to investigate the effect of MMF on monocyte Toll-like receptor 4 (TLR4) signaling in the early stages of renal ischemia/reperfusion injury (IRI) of mice.. Sixty BALB/C mice were randomly divided into two groups: an IRI group, in which renal IRI was induced by clamping the renal pedicles for 45 minutes, and an MMF group, in which MMF was given (40 mg×kg(-1)×d(-1), intraperitoneally) from 2 days before renal IRI. The plasma creatinine level and renal tissue damage of each group mice were observed 6, 12, 24, and 48 hours after reperfusion. The concentration of plasma high-mobility group box 1 (HMGB-1) (TLR4 ligand), interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor α (TNF-α) and the expression of TLR-4 on monocytes were determined.. The plasma creatinine concentration in the MMF group was lower compared to the IRI group (after reperfusion of 6, 12, 24, or 48 hours, P < 0.05). Pathological analysis showed that the renal damage was slighter, TLR-4 expression was reduced (after reperfusion of 6, 12, 24, or 48 hours, P < 0.05), and the concentration of cytokines in the plasma was lower (P < 0.05) in the MMF group. No differences in the concentrations of HMGB-1 were observed (P > 0.05).. Monocyte TLR4 signaling is important in the early stage of kidney IRI, but MMF can inhibit it and improve renal function.

Topics: Acute Kidney Injury; Animals; Chemokine CCL2; Creatinine; Cytokines; HMGB1 Protein; Male; Mice; Mice, Inbred BALB C; Monocytes; Mycophenolic Acid; Random Allocation; Reperfusion Injury; Signal Transduction; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Mycophenolic acid has played an important role in treating immunosuppression and autoimmune diseases. Nevertheless, the agent needs a high dosage in treatment, following some side effects. To tackle this problem, in this study, mycophenolic acid-glucosamine conjugate (MGC), modified by 2-glucosamine, was synthesized to achieve kidney targeting and improved drug efficacy with a lower dosage. (1)H NMR, (13)C NMR and HRMS spectroscopy were used to verify the conjugate whose stability was good in vitro. The transport of MGC by human proximal renal tubular epithelial HK-2 cells was temperature-, time-, concentration-dependent and saturable, suggesting the involvement of carrier-mediated uptake. In addition, the cellular uptake of MGC dropped substantially with the inhibition of megalin receptor. The specific tissue distribution indicated the commendable renal-targeting capability of MGC. The concentration of MGC was improved in the kidney except for other tissues, about 6.76 times higher than that of MPA. Further, the bioavailability of MGC in plasma decreased as compared with mycophenolic acid. Moreover, therapeutic effect of MGC was enhanced significantly compared with MPA in the acute kidney injury model. All the findings suggested the potential of mycophenolic acid-glucosamine conjugate in kidney targeted drug delivery.

Topics: Animals; Biological Availability; Blood Urea Nitrogen; Cell Line; Cell Survival; Creatinine; Drug Delivery Systems; Glucosamine; Humans; Kidney; Male; Mice; Mycophenolic Acid; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tissue Distribution

Stroke is a major cause of mortality and disability worldwide. Presently, recombinant tissue plasminogen activator is the only approved drug for the management of acute ischemic stroke. However, it has limitations like narrow therapeutic window and increased risk of intracranial hemorrhage. In previous studies, immunosuppressive agents such as cyclosporine A and tacrolimus have shown neuroprotection by improving neurological functions and infarct volume in models of ischemic stroke. Therefore, the present study was designed to evaluate the effect of mycophenolate mofetil (MMF) on the cerebral ischemic injury in the middle cerebral artery occlusion (MCAo) model in rats. MCAo was carried out in male Wistar rats by inserting an intraluminal thread. One hour after MCAo, the animals were treated with MMF (50, 100, 200mg/kg, i.p.). Reperfusion was done after 2h of occlusion. Thirty minutes after reperfusion, animals were subjected to diffusion-weighted magnetic resonance imaging for assessment of neuroprotective effect of MMF. Twenty four hours after MCAo, motor performance was assessed and the animals were euthanized for estimation of brain malondialdehyde, glutathione, myeloperoxidase and nitric oxide levels. The effect of MMF on apoptosis was also evaluated. MMF significantly attenuated the percent infarct area, apparent diffusion coefficient and signal intensity as compared to a vehicle treated group. Treatment with MMF prevented the motor impairment and significantly reversed the changes in levels of malondialdehyde, glutathione, myeloperoxidase and nitric oxide. MMF treatment significantly reduced the apoptosis. Data of the present study indicate neuroprotective effect of MMF in the experimental model of ischemic stroke.

Topics: Animals; Glutathione; Hand Strength; Infarction, Middle Cerebral Artery; Magnetic Resonance Imaging; Male; Malondialdehyde; Mycophenolic Acid; Neuroimaging; Neuroprotective Agents; Oxidative Stress; Peroxidase; Rats; Rats, Wistar; Reperfusion Injury; Rotarod Performance Test

Immunosuppressants have been widely used in renal transplantation, in which ischemia-reperfusion injury is inevitable. Mycophenolate mofetil (MMF) is a relative novel immunosuppressant and also attenuates ischemia-reperfusion injury in the acute phase, but its long-term effects are still obscure. Unilateral renal ischemia-reperfusion injury model was established in Sprague-Dawley rats and 30 mg/kg/day MMF or natural saline was administered a day before the surgery. Renal function was monitored, and histological changes and fibrosis in the kidney were evaluated in both short and long terms. TGF-β1 secretion and MCP-1 expression were determined by immunohistochemistry and real-time PCR respectively. The infiltration of macrophages in renal tissues was also assessed by fluorescence activated cell sorting (FACS). MMF treatment significantly improved renal function in ischemia-reperfusion injury rats in the short and long-term and also effectively prevented interstitial fibrosis. TGF-β1 secretion and MCP-1 expression in the renal tissue of MMF-treated rats were much lower than those in natural saline-treated rats, with much less macrophage infiltration as well. MMF treatment effectively prevented the deterioration of renal function and interstitial fibrosis in ischemia-reperfusion injury rats, which may be associated with decreased TGF-β1, MCP-1 and macrophages. These results provide evidence for the choice of MMF in the renal transplant patients not only for acute renal injury but also for long-term survival of renal allograft.

Topics: Animals; Chemokine CCL2; Dose-Response Relationship, Drug; Fibrosis; Gene Expression Regulation; Immunosuppressive Agents; Kidney; Lymphocytes; Macrophages; Male; Mycophenolic Acid; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Time Factors; Transforming Growth Factor beta1

Prolonged cold preservation frequently causes delayed renal graft function resulting from tubular epithelial injury. Inhibition of signal transduction downstream from protein kinase C (PKC) may reduce renal ischemia-reperfusion injury and confer renal graft protection. We therefore evaluated the effect of sotrastaurin, a small-molecule inhibitor of Ca²⁺-dependent and Ca²⁺-independent PKC isoforms, in comparison with mycophenolic acid (MPA) on rat renal transplants with prolonged cold preservation.. Donor kidneys from male Lewis rats were cold stored in University of Wisconsin solution for 24 hr before syngeneic grafting. Recipients received sotrastaurin (30 mg/kg twice daily), MPA (20 mg/kg/day), or vehicle through gavage starting 1 hr after surgery. Renal function was evaluated by serum creatinine and histology on day 2 (acute injury) and day 7 (repair phase) after transplantation. Postreperfusion inflammation was determined by real-time polymerase chain reaction of proinflammatory genes and histology. Signaling mechanisms were studied by Western blotting and immunohistochemistry.. Sotrastaurin enhanced immediate transplant function, attenuated epithelial injury, and accelerated renal function recovery compared with MPA. Despite the stronger anti-inflammatory capacity of MPA, only sotrastaurin treatment achieved significant cellular protection with persisting reduced apoptosis of tubular epithelial cells. Decreased phosphorylation of extracellular signal-regulated protein kinase and p66Shc adaptor protein, both involved in cellular stress and apoptosis, were likely the responsible mechanism of action.. The PKC inhibitor sotrastaurin effectively ameliorated ischemia-reperfusion organ damage and promoted cytoprotection in a clinically relevant model of extended renal cold preservation followed by transplantation. Pharmacologic targeting of PKC may be beneficial for recipients receiving renal transplants at risk for delayed graft function.

Topics: Adenosine; Allopurinol; Animals; Apoptosis; Biomarkers; Blotting, Western; Cell Proliferation; Cold Temperature; Creatinine; Cytokines; Cytoprotection; Delayed Graft Function; Glutathione; Immunohistochemistry; Inflammation Mediators; Insulin; Kidney; Kidney Transplantation; Male; Mycophenolic Acid; Organ Preservation; Organ Preservation Solutions; Protein Kinase C; Protein Kinase Inhibitors; Pyrroles; Quinazolines; Raffinose; Rats; Rats, Inbred Lew; Real-Time Polymerase Chain Reaction; Reperfusion Injury; Signal Transduction; Time Factors

Ischemia reperfusion injury (IRI) is one of the risk factors for delayed graft function, acute rejection and long term allograft survival after kidney transplantation. IRI is an independent antigen inflammatory process that produces tissue damage. Our objective was to study the impact of immunosuppressive treatment (IS) on IRI applying only one dose of IS before orthotopic kidney autotransplantation.. Twenty-four rats allocated in four groups were studied. One group served as control (G1: autotransplanted rats without IS) and the rest received IS 12 h before kidney autotransplantation (G2: Rapamycin, G3: Mycophenolate mofetil and G4: Tacrolimus).. Improved renal function and systemic inflammatory response were found among IS groups compared to the control group (Delta Urea p<0.0001; Delta Creatinine p<0.0001; Delta C3 p<0.001). The number of apoptotic nuclei in renal medulla in G1 was higher than in IS groups (p<0.0001). Tubular damage was less severe in IS groups respecting G1 (p<0.001). C3, TNF-α and IL-6 expression in kidney samples was reduced when IS was used compared to the control group. No differences were observed among the different immunosuppressive drugs tested. However, Heme oxygenase-1(HO-1) was increased only in Rapamycin treatment.. These data suggest that the use of IS administered before transplant attenuates the IRI process after kidney transplantation in an animal model.

Topics: Animals; Apoptosis; Complement C3; Creatinine; Graft Survival; Heme Oxygenase-1; Immunosuppressive Agents; Interleukin-6; Kidney Function Tests; Kidney Transplantation; Kidney Tubules; Male; Mycophenolic Acid; Rats; Rats, Wistar; Reperfusion Injury; Sirolimus; Tacrolimus; Transplantation, Autologous; Urea

Renal ischaemia-reperfusion injury (IRI) acutely decreases glomerular filtration rate (GFR) and impairs kidney function in the long term. Pre-treatment with chaetomellic acid (KM), an inhibitor of membrane-bound Ha-Ras, has demonstrated beneficial effects on acute renal ischaemia.. We tested whether mycophenolate mofetil (MMF, 20 mg/day for 4 days before IRI), an immunosuppressor with anti-inflammatory properties, improved renal outcome in uninephrectomized rats after IRI (45 min of renal ischaemia), alone or in combination with KM.. One day after ischaemia, GFR was markedly depressed in untreated rats (-75% vs. normal rats, P < 0.001), and pre-treatment with MMF did not modify this fall (-75%, P < 0.001 vs. normal). KM (0.23 microg/kg before IRI) greatly prevented GFR loss (-39% vs. normal, P < 0.05), but its action was not further improved by the combined administration with MMF (GFR, -45% vs. normal, P < 0.05). MMF significantly reduced ICAM-1 expression and monocyte recruitment (P < 0.05 vs. untreated rats); nevertheless, renal histology of MMF rats was similar to that of untreated rats. Additional rats were examined 6 months after IRI: untreated rats with IRI showed reduced renal function (-42% vs. normal, P < 0.01) and proteinuria (P < 0.001 vs. normal); rats pre-treated with MMF showed a similar pattern, whereas rats treated with KM before IRI presented a better GFR (-20% vs. normal, not significant) and near-normal values of proteinuria. The combination of KM + MMF gained the same results.. Pre-treatment with MMF before IRI does not confer functional or morphological protection to the kidney, despite the reduced expression of some inflammatory markers. The combination of MMF + KM does not offer additional advantages to solitary KM treatment.

Topics: Animals; Glomerular Filtration Rate; Immunohistochemistry; Immunosuppressive Agents; Intercellular Adhesion Molecule-1; Kidney; Male; Maleates; Mycophenolic Acid; ras Proteins; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Lymphocytes participate in the early pathogenesis of ischemia-reperfusion injury (IRI) in kidney; however, their role during repair is largely unknown. Recent data have shown that Foxp3(+) regulatory T cells (Tregs) traffic into kidney during healing from IRI and directly participate in repair. Since lymphocyte-targeting therapy is currently administered to prevent rejection during recovery from IRI in renal transplants, we hypothesized that mycophenolate mofetil (MMF) would alter Treg trafficking and kidney repair. C57BL/6J and T cell deficient mice underwent unilateral clamping of renal pedicle for 45 min, followed by reperfusion, and were sacrificed at day 10. Mice were treated with saline (C) or MMF (100mg/kg) i.p. daily starting at day 2 until sacrifice (n=5-12/group). MMF worsened kidney tubular damage compared to C at 10 days (cortex and outer medulla: p<0.05) in wild-type mice; tubular apoptotic index was increased in cortex in MMF group as well (p=0.01). MMF reduced the total number of kidney-infiltrating mononuclear cells (p<0.001 versus C) and the percentages of TCRbeta(+)CD4(+) and TCRbeta(+)CD8(+) T cells (p<0.01), but not natural killer (NK), NKT or B lymphocytes. MMF specifically reduced kidney Foxp3(+) Tregs (0.82+/-0.11% versus 1.75+/-0.17%, p<0.05). Tubular proliferative index and tissue levels of basic FGF were increased in MMF group (p<0.05), IL-10 and IL-6 were decreased (p<0.05). To evaluate if MMF effect occurred through non-lymphocytic cells, T cell deficient mice were treated with MMF. Tubular injury in T cell deficient mice was not affected by MMF treatment, though MMF-treated animals had increased VEGF and decreased PDGF-BB protein tissue levels compared to controls (p<0.05). Thus, MMF modifies the structural, epithelial proliferative and inflammatory response during healing, likely through effects on T cells and possibly Tregs. Kidney repair after IRI can be altered by agents that target lymphocytes.

Topics: Animals; Disease Models, Animal; Forkhead Transcription Factors; Immunosuppressive Agents; Kidney; Kidney Tubular Necrosis, Acute; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mycophenolic Acid; Reperfusion Injury; T-Lymphocytes, Regulatory

Ischemia reperfusion injury (IRI) represents a serious problem of transplanted kidneys from a non-heart-beating donor (NHBD). It is probably the main cause of primary a function or delayed graft function. The aim of the experimental study was to demonstrate on an experimental model the possibilities of reduction of IRI by intravenous application of antioxidants or immunosuppressives to the recipient before the kidney transplantation.. Piglets weighing between 20-25 kg were used (N = 45) for the experiment. Intravenous application of multivitamins (GI) and a combination of immunosuppressives (GII) was tested one hour before the kidney transplantation from the NHBD. As a control a group (GIII) with simple NHBD modelling was used. At intervals of 0, 20, 60 and 120 minutes after the kidney transplantation, plasma levels of malondiadehyde (MDA) and reduced glutathione (GSH) were assessed. Before and 120 minutes after transplantation tissue concentrations of both factors were assessed in the transplanted kidney.. A permanent increase in MDA plasma concentrations occurred in GIII. In GI and GII, after a temporary increase of MDA plasma levels in the first 20 minutes after reperfusion, there was their permanent decrease then. (p < 0.05, resp. p < 0.01). The differences in the MDA plasma levels of GI and GII groups did not reach statistical significance. The both groups differed from GIII (p < 0.001). GSH plasma levels and also tissue concentrations of MDA and GSH were not statistically significant in any group in the course of the experiment.. Intravenous application of multivitamins or immunosuppressives before kidney transplantation could have a significant influence on the immediate function of transplanted kidneys from a NHBD.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Glutathione; Hydrocortisone; Immunosuppressive Agents; Infusions, Intravenous; Kidney Transplantation; Male; Malondialdehyde; Mycophenolic Acid; Reperfusion Injury; Sus scrofa; Vitamins

Mycophenolate mofetil (MMF) has been gradually introduced into clinical liver transplantation in recent years. However, the effects of MMF on hepatic ischemia/reperfusion (I/R) injury and the potential mechanisms involved are not totally understood. We aimed to evaluate whether MMF could attenuate hepatic I/R injury. MMF (20 mg/kg) or vehicle was administered to Wistar rats by gavage. The rats were then subjected to hepatic ischemia. Liver cell apoptosis and the levels of aspartate aminotransferase, myeloperoxidase (MPO), xanthine oxidase (XOD) and malondialdehyde (MDA) were determined. Expression of vascular cell adhesion molecule-1 (VCAM-1) and activation of mitogen-activated protein kinases (MAPKs) were also investigated. Furthermore, the hepatic microcirculation was observed by intravital fluorescence microscopy. Rats pretreated with MMF exhibited significant alleviation of their postischemic liver function. Liver cell apoptosis and the tissue MPO, XOD and MDA levels were decreased by MMF pretreatment. MMF also improved I/R-induced hemodynamic turbulence, as evidenced by reduced hepatic perfusion failure and decreased numbers of rolling and adherent leukocytes. I/R injury induced activation of the MAPKs pathway while expression of VCAM-1 was downregulated by MMF pretreatment. In summary, MMF attenuates hepatic I/R injury through suppression of the production of reactive oxygen species and amelioration of postischemic microcirculatory disturbances.

Topics: Animals; Apoptosis; Endothelial Cells; Enzyme Inhibitors; Leukocytes; Liver; Male; MAP Kinase Signaling System; Microcirculation; Microscopy, Fluorescence; Mycophenolic Acid; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury

Ischemia reperfusion injury (IRI) is a serious problem of transplanted kidneys from a non-heart-beating donor (NHBD). IRI is probably the main cause of primary disfunction or delayed graft function. The aim of this study was to demonstrate the reduction of IRI by intravenous application of antioxidants or immunosuppressives to the recipient before the kidney transplantation in an experimental model.. Piglets weighing between 20-25 kg were used (n=45) for the experiment. Intravenous application of multivitamins (GI) and a combination of immunosuppressives (GII) was tested one hour before the kidney transplantation from the NHBD. In control group (GIII) simple NHBD modelling was used. Plasma levels of malondiadehyde (MDA) and reduced glutathione (GSH) were assessed at intervals of 0, 20, 60 and 120 minutes after the kidney transplantation. Concentrations of both MDA and GSH were also assessed in the transplanted kidney before and 120 minutes after transplantation.. A permanent increase in MDA plasma concentrations occurred in GIII. In GI and GII, after a transient increase in MDA plasma levels within the first 20 minutes after reperfusion, it decreased permanently (p<0.05, p<0.01). MDA plasma levels were not significantly different between GI and GII groups, but both groups differed from GIII (p<0.001). GSH plasma levels and tissue concentrations of MDA and GSH were not statistically significant in any group in the course of the experiment.. Intravenous application of multivitamins or immunosuppressives before kidney transplantation could have a significant influence on the immediate function of transplanted kidneys from a NHBD (Tab. 3, Fig. 1, Ref. 13). Full Text (Free, PDF) www.bmj.sk.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Glutathione; Hydrocortisone; Immunosuppressive Agents; Infusions, Intravenous; Kidney Transplantation; Male; Malondialdehyde; Mycophenolic Acid; Reperfusion Injury; Sus scrofa; Vitamins

The present study determined the effect of immune suppression with mycophenolate mofetil (MMF) on sodium-sensitive hypertension following recovery from ischemia reperfusion (I/R)-induced acute renal failure. Male Sprague-Dawley rats fed 0.4% NaCl chow were subjected to 40 min bilateral I/R or control sham surgery. After 35 days of recovery, when plasma creatinine levels had returned to normal, the rats were switched to 4.0% NaCl chow for 28 days and administered vehicle or MMF (20 mg.kg(-1).day(-1) ip). High-salt mean arterial pressure was significantly higher in I/R rats (144 +/- 16 mmHg) compared with vehicle-treated sham rats (122 +/- 2 mmHg). Treatment of I/R rats with MMF during the period of high salt intake prevented the salt-induced increase in arterial pressure (114 +/- 3 mmHg). Conscious creatinine clearance was lower in I/R rats (0.27 +/- 0.07 ml.min(-1).100 g body wt(-1)) compared with vehicle-treated sham rats (0.58 +/- 0.04 ml.min(-1).100 g body wt(-1)); MMF treatment prevented the decrease in creatinine clearance in I/R rats (0.64 +/- 0.07 ml.min(-1).100 g body wt(-1)). I/R injury also significantly increased glomerular tissue damage and increased the presence of ED-1 positive (macrophages) and S100A4 positive cells (fibroblasts) in the renal interstitium. The I/R rats treated with MMF exhibited a significant reduction in infiltrating macrophages and fibroblasts and decreased histological damage. The present data indicate that infiltrating immune cells mediate or participate in the development of sodium-sensitive hypertension and renal damage in rats apparently recovered from renal I/R injury.

Topics: Acute Kidney Injury; Animals; Blood Pressure; Cell Movement; Creatinine; Disease Models, Animal; Fibroblasts; Hypertension; Immunosuppressive Agents; Ischemia; Kidney; Macrophages; Male; Mycophenolic Acid; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sodium Chloride, Dietary; Time Factors

This study is aiming to investigate the mechanism and drug intervention of chronic allograft nephropathy (CAN) induced by renal ischemia-reperfusion injury.. The closed colony strain Sprague-Dawley (SD) and Wistar Rats were used as donor and recipient, respectively. Orthotopic kidney transplantation was performed following the procedure of our previous study. The rats were divided into five groups: Group A only received CsA with 10 mg/(kg x d); except CsA, Group B,C,D received Yi Sheng injection with 4 mg/(kg x d), 8 mg/(kg x d), and MMF (20 mg/(kg x d)], respectively. Group E was control group. According to Banff standard, the serum creatinine (SCr) level and pathological change of rat grafted kidney were observed at the 4th, 8th and 12th weeks post-transplantation. The immunohistochemistry and real-time fluorescence quantitative polymerase chain reaction were used to comprehend the localization and expression of TGFbeta1 and Smad2, 7 in the transplant kidney.. Compared with the lower dosage group, the differences of SCr level and pathological changes of CAN at all the time points after 8th week were statistically significant in the high dosage Yi Sheng group. It was showed that the Yi Sheng injection had the protective effect on CAN with a dose-dependent fashion. After transplantation, the rat kidney-sclerosis model showed that the up-regulated expressions of TGF-P, and Smad2 and the down-regulated expression of Smad7 in Group A and Group B were statistically significant, which meant that the difference was obvious when Group A compared with the other 4 groups. The expressions of TGF-beta1, and Smad2 were strongly positive in tubular epithelial cell, interstitial cell and glomerulus, while the expression of Smad7 was weak. Thickening of endovascular could significantly be inhibited in high dosage of Yi Sheng and MMF group.. The up-regulated expressions of TGF-beta1 and Smad2 and the down-regulated expression of Smad7 may accelerate the progression of CAN alone or with immune factors. The traditional Chinese medicine Yi Sheng injection and MMF can down-regulate the expression of TGF-beta1 and Smad2 and block the down-regulated expression of Smad7, which may postpone and lessen the progression of CAN.

Topics: Animals; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Gene Expression Regulation; Immunosuppressive Agents; Kidney; Kidney Diseases; Kidney Transplantation; Mycophenolic Acid; Rats; Rats, Sprague-Dawley; Rats, Wistar; Reperfusion Injury; Smad2 Protein; Smad7 Protein; Transforming Growth Factor beta1; Transplantation, Homologous

Renal ischemia and hypertension have been suggested to be involved in the progression of renal diseases. Recently, we developed a model of accelerated major histocompatibility complex-independent renal injury, where high-renin hypertension aggravates functional and morphological changes induced by ischemia/reperfusion (I/R). In this model, we evaluated the effect of immunosuppressant mycophenolate mofetil (MMF) to test its capability to slow the progression of accelerated nephropathy.. 34 anesthetized uninephrectomized hypertensive transgenic (mREN2)27 rats (TGR) received a clamp on the renal pedicle for 45 min. Animals were treated with MMF 10 mg/kg/day (n = 10), 20 mg/kg/day (n = 10) or placebo (n = 10) orally via gavage for 12 weeks. Four animals were sham operated and not treated. Proteinuria and blood pressure were evaluated throughout the experiment. At the end of the experiment, kidney function was evaluated and kidneys harvested for morphological analysis and immunohistochemistry (CD4+, CD8+ lymphocytes and specific rat monocyte/macrophage marker ED-1+ cells).. At week 12, both MMF-treated groups had lower proteinuria as compared to the placebo group (MMF 10: 22.4 +/- 9.8, MMF 20: 20.9 +/- 5.6 vs. 126.7 +/- 35.8; p < 0.01; sham 28.1 +/- 1.4 mg/day) and reduced glomerulosclerosis (MMF 10: 11.4 +/- 7.8, MMF 20: 5.2 +/- 2.7 vs. 20.9 +/- 10.9; p < 0.05; sham 15.7 +/- 9.2%). There were no differences in systolic blood pressure among groups. MMF-treated rats had lower CD4+ (MMF 10: 61.2 +/- 46.4, MMF 20: 29.3 +/- 18.2 vs. 125.3 +/- 42.8; p < 0.01, sham 84.9 +/- 6.1 cells/field of view) and CD8+ (MMF 10: 13.7 +/- 10.2, MMF 20: 10.0 +/- 8.1 vs. 37.8 +/- 14.3; p < 0.01; sham: 31.8 +/- 7.6 cells/field of view) lymphocytes infiltration and ED-1 macrophages infiltration (MMF 10: 5.5 +/- 6.4, MMF 20: 2.5 +/- 2.8 vs. 16.7 +/- 4.1; p < 0.01; sham 12.2 +/- 4.6 cells/field of view) than placebo-treated rats.. Our results thus support the hypothesis about the key role of immune mechanisms in progression of chronic nephropathies.

Topics: Animals; Animals, Genetically Modified; Disease Models, Animal; Disease Progression; Hypertension, Renal; Immunosuppressive Agents; Kidney; Kidney Function Tests; Male; Mycophenolic Acid; Rats; Reperfusion Injury

Ischemia-reperfusion injury affects posttransplant renal function, directly increases the probability of acute rejection, and is associated with chronic rejection and impaired long-term function. Animal studies suggest that ischemic preconditioning enhances resistance to ischemia and may be augmented by treating donors using immunosuppressant agents. This study sought to confirm the hypothesis that a combination of ischemic training and immunosuppression prior to renal harvest would maximize a transplanted kidney's resistance to ischemia-reperfusion injury.. Landrace pigs underwent either preharvest immunosuppression plus left kidney ischemic training (group 1, n=6) or ischemic training alone (group 2, n=6). Immunosuppression was composed of mycophenolate mofetil (20 mg/kg) and tacrolimus (0.1 mg/kg) administered intravenously 30 minutes before training. Training comprised 2 cycles of left renal pedicle occlusion for 5 minutes followed by release (reperfusion) for 10 minutes. Warm renal ischemia was then induced by clamping the left renal pedicle for 30 minutes, followed by heterotopic left kidney transplantation. Blood from the transplanted kidney renal vein was sampled directly at 0, 10, 20, 40, and 60 minutes posttransplantation for malondialdehyde (a reactive oxygen species marker), tumor necrosis factor-alpha (TNF-alpha), interleukins 6 and 8 (inflammatory cytokines), and erythrocyte-reduced glutathione (an antioxidant). Renal histology was graded on a 3-point scale.. Reperfusion levels of malondialdehyde, TNF-alpha, and interleukin 6 were significantly lower in group 1 at both 40 and 60 minutes. None of the animals in group 1 (0/6) that received preharvest immunosuppression showed severe interstitial inflammation, compared with 4 of 6 animals in group 2 that did (P<.03).. Preharvest immunosuppression with mycophenolate mofetil and tacrolimus significantly decreases immediate posttransplant reactive oxygen species and inflammatory cytokine production, enhances the protective effect of ischemic training, and should not only reduce ischemiareperfusion injury in transplanted kidneys but also should enhance immediate and long-term graft function while preventing acute rejection.

Topics: Animals; Immunosuppressive Agents; Kidney; Kidney Transplantation; Male; Malondialdehyde; Mycophenolic Acid; Preoperative Care; Reperfusion Injury; Swine; Tacrolimus; Treatment Outcome

We have previously shown the long-term influence of renal ischemia/reperfusion (I/R) injury and immunosuppression on fibrotic genes and apoptosis in a rat model. For the first time, we have now investigated the effects of I/R and immunosuppression on inflammation and caspase activation.. I/R injury was induced in the right kidney and the left was removed. Cyclosporin (CsA) (10 mg/kg), tacrolimus (0.2 mg/kg), rapamycin (1 mg/kg), or mycophenolate mofetil (MMF) (10 mg/kg) was then administered for 16 weeks. The effects of I/R and immunosuppressants on interstitial inflammation, interleukin (IL)-1beta expression, caspase-1 and caspase-3 activation, tubulointerstitial damage, and fibrosis were evaluated.. ED-1+ (a specific rat monocyte/macrophage marker) cells were mainly localized in the tubulointerstitium and periglomerular areas and increased in I/R group compared to controls (P < 0.01). This was further increased by CsA, but decreased by tacrolimus, rapamycin, or MMF (P < 0.05). The 17 kD active IL-1beta remained unchanged, but 35 kD IL-1beta precursor was decreased by rapamycin in comparison with I/R group (P < 0.05). The 45 kD or 20 kD caspase-1 was increased by I/R or CsA, respectively, and decreased by rapamycin (P < 0.05). The 24 kD caspase-3, which proved to be an active caspase-3 subunit, was increased in I/R and CsA groups and deceased by tacrolimus, rapamycin, or MMF (P < 0.05), but not 32 kD precursor or 17 kD active caspase-3. The activity data of caspase-1 and caspase-3 exhibited the same trend as Western blotting data. The staining of active caspase-3 was scattered in kidneys, mainly in tubular and interstitial areas, which was consistent with that of ED-1+ cells. There was a strong positive correlation between interstitial inflammation and 24 kD caspase-3 expression or caspase-3 activity (r = 0.814 or 0.484), all of which were also closely related with urinary protein (r = 0.537, 0.529, or 0.517), serum creatinine (r = 0.463, 0.573, or 0.539), tubulointerstitial damage (r = 0.794, 0.618, or 0.712) and fibrosis (r = 0.651, 0.567, or 0.469), all P < 0.01.. This study shows that the mechanisms of long-term I/R injury and immunosuppressants treatment include interstitial inflammation and caspase activation, most clearly demonstrated by the 24 kD active caspase-3.

Topics: Animals; Apoptosis; Caspase 1; Caspase 3; Caspases; Chronic Disease; Cyclosporine; Electrophoresis, Polyacrylamide Gel; Extracellular Matrix; Fibrosis; Glomerulonephritis; Immunosuppressive Agents; Interleukin-1; Male; Mycophenolic Acid; Rats; Rats, Wistar; Reperfusion Injury; Sirolimus; Tacrolimus

Lung ischemia-reperfusion injury (LIRI) is associated with an increased incidence of both primary graft failure and obliterative bronchiolitis. The immunosuppressant mycophenolate mofetil (MMF) has recently been shown to attenuate inflammatory injury in acute ischemia-reperfusion models via a mechanism that is presently unclear. These experiments studied the effects of MMF in a warm, in situ LIRI model, focusing on transcriptional regulation of pro-inflammatory mediators.. Left lungs of rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received 10 mg/kg of intravenous MMF at 2 hours before ischemia. Left lung injury was quantitated by myeloperoxidase (MPO) content, permeability indices and bronchoalveolar lavage (BAL) inflammatory cell counts. Lungs were analyzed by electrophoretic mobility shift assay (EMSA) for transcription factor transactivation and by enzyme-linked immunoassay for BAL chemokine protein content.. MMF significantly reduced lung vascular permeability indices, MPO content and alveolar leukocyte counts at 4 hours of reperfusion. There was significant attenuation of activator protein 1 (AP-1) and early growth response 1 (EGR-1) transactivation, whereas nuclear factor-kappaB (NF-kappaB) was unaffected. Reductions in bronchoalveolar lavage monocyte chemoattractant protein 1 (MCP-1) and cytokine-induced neutrophil chemoattractant (CINC) protein content were found at 4 hours of reperfusion.. MMF limits lung ischemia-reperfusion-induced increases in vascular permeability and inflammatory cell sequestration in lung parenchyma and alveolar spaces. The protection is mediated at the transcriptional level via an attenuation of early EGR-1 and AP-1 transactivation, which was found to be associated with reduced late MCP-1 and CINC protein secretion. The use of MMF in concert with an agent that affects NF-kappaB activation may provide even further protection against lung reperfusion injury as multiple inflammatory pathways are inhibited.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bronchiolitis Obliterans; Bronchoalveolar Lavage Fluid; Chemokines; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Graft Rejection; Inflammation; Lung; Lung Transplantation; Male; Mycophenolic Acid; Permeability; Peroxidase; Postoperative Complications; Rats; Rats, Long-Evans; Reperfusion Injury; Transcription Factors; Transcription, Genetic

Grafts from so-called "marginal donors" are increasingly used for organ transplantation. The combination of reduced organ quality and additional inflammatory damages may be particularly detrimental in these grafts. In a previous study, we showed the beneficial effects on long-term graft outcome of "suboptimal" grafts by the induction of heme oxygenase-1. Here we tested the impact of short-term donor treatment with established immunosuppressants.. Twelve-month-old Fischer 344 donor rats either were treated with prednisolone, mycophenolate mofetil, RAD, or FK506 24 hr and 1 hr before organ harvesting or remained untreated. Renal allografts were perfused with University of Wisconsin solution and kept at 4 degrees C for an ischemic period of 2 hr. Morphologic, immunohistologic, and real time reverse transcriptase-polymerase chain reaction analyses for relevant markers were performed at serial intervals and at the end of the observation period (6 months).. All animals survived the observation period, although the ischemic time resulted in accelerated chronic graft dysfunction. Grafts from donors treated with prednisolone or FK506 demonstrated significantly improved graft function and structure by 6 months. Mononuclear infiltrates were significantly reduced by the end of the observation period, whereas intragraft mRNA levels of tumor necrosis factor-alpha and interleukin-10 were significantly altered during the early period after transplantation. Minor improvements in graft function and histologic alterations of suboptimal grafts were observed after pretreatment with mycophenolate mofetil and RAD.. Donor treatment with approved immunosuppressants, in particular prednisolone or FK506, represents a novel therapeutic strategy of clinical relevance, most importantly when using grafts from marginal donors.

Topics: Age Factors; Animals; Antigens, Surface; Cytokines; Gene Expression; Graft Survival; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Immunosuppressive Agents; Kidney Transplantation; Male; Mycophenolic Acid; Prednisolone; Protoporphyrins; Rats; Rats, Inbred F344; Reperfusion Injury; Tacrolimus; Tissue Donors; Transplantation, Homologous

Post-ischemia/reperfusion (I/R) damage, accompanied by leukocyte infiltration, is unavoidable in renal transplantation, as is the need for immunosuppressive treatment. Influence of immunosuppressive treatment on post-I/R renal damage, nonalloimmune cellular infiltration, and regeneration is not well studied.. Uninephrectomized inbred LEW rats were submitted to warm renal ischemia of 45 minutes/60 minutes, and received different immunosuppressive regimens: cyclosporine (CsA) 10 mg/kg/day subcutaneously in the neck daily, or mycophenolate mofetil (MMF) 20 mg/kg/day by daily oral gavage. Control animals underwent sham operation (unilateral nephrectomy) with immunosuppressive treatment or ischemia with vehicle administration. In addition the effect of MMF/mycophenolic acid (MPA) on renal tubule cell proliferation in culture was studied with bromodeoxyuridine incorporation.. The post-I/R interstitial cellular infiltration/proliferation consisted mainly of mononuclear leukocytes [first monocytes/macrophages (Mo/MPhi) followed by CD4+ cells]. This mononuclear cell infiltration became apparent 24 hours after injury at the time of acute tubular necrosis, and was most prominent during the phase of regeneration. Severe I/R combined with CsA aggravated morphologic damage and dysfunction, without effect on tubular cell proliferation and tubular regeneration. Early leukocyte infiltration was qualitatively and quantitatively comparable to control animals, yet decreased moderately later in time. In contrast, MMF in combination with severe I/R did not influence initial morphologic damage and dysfunction. Although the initial leukocyte infiltration was comparable to control animals, the subsequent mononuclear cell accumulation, especially CD4 T cells decreased dramatically during MMF treatment. This was concomitant with a decrease of tubular cell proliferation and hence tubular regeneration. Increasing MPA concentrations in renal tubular cell culture caused a significant decrease in total cell number, and an almost arrest of bromodeoxyuridine incorporation, as measurement of cell proliferation.. Immunosuppressive treatment with CsA or MMF affected significantly and in a different manner post-I/R renal morphologic damage, interstitial leukocyte, accumulation and regeneration.

Topics: Animals; Cell Division; Cyclosporine; Immunosuppression Therapy; Immunosuppressive Agents; Kidney; Kidney Tubular Necrosis, Acute; Leukocytes; Male; Mycophenolic Acid; Rats; Rats, Inbred Lew; Regeneration; Renal Circulation; Reperfusion Injury; Severity of Illness Index

Immunosuppressive agents may have an impact on ischemia/reperfusion (I/R) injury. The immunosuppressant mycophenolate mofetil (MMF) presents properties that can attenuate such injury. This study investigated the effects of MMF on renal I/R injury. Male Wistar rats received MMF (20 mg/kg per d) or vehicle by gavage beginning 2 d before ischemia and maintained during the entire study. Ischemic injury was induced by bilateral renal arteries occlusion for 60 min. Control rats received MMF and underwent sham operation. At days 1, 2, and 14, post-ischemia renal function was assessed and kidneys were removed for histologic and immunohistochemical studies. MMF given to nonischemic rats did not alter renal function. There was no functional protection at 24 h post-ischemia with MMF. At 2 d, post-ischemia rats pretreated with MMF presented higher inulin clearance compared with untreated rats (0.42 +/- 0.04 versus 0.15 +/- 0.02 ml/min per 100 g; P < 0.001) and attenuated renal blood flow decrease (5.23 +/- 0.28 versus 3.24 +/- 0.37 ml/min; P < 0.01). The immunostaining for intercellular adhesion molecule-1 (ICAM-1) was less intense in rats pretreated with MMF. These rats also presented an earlier decreased infiltrating macrophages/lymphocytes and cell proliferation at day 1 post-ischemia. The functional and immunohistochemical analyses performed at day 14 post-ischemia returned to values similar to controls in both groups of rats. To determine whether mycophenolic acid (MPA) could induce cytoprotection, the effects of MPA on normoxic and hypoxic/reoxygenated (H/R) isolated tubule suspensions were also investigated. MPA was not deleterious to normoxic tubules and it was not protective against H/R tubules. In conclusion, pretreatment with MMF attenuates I/R injury in rats and does not limit the recovery from ischemia. The protective effect of MMF by reducing inflammation precedes the hemodynamic changes and tubular injury.

Topics: Acute Kidney Injury; Animals; Ectodysplasins; Immunohistochemistry; Immunosuppressive Agents; Intercellular Adhesion Molecule-1; Ischemia; Kidney; Kidney Tubules, Proximal; L-Lactate Dehydrogenase; Lymphocytes; Male; Membrane Proteins; Mycophenolic Acid; Proliferating Cell Nuclear Antigen; Rats; Rats, Wistar; Renal Circulation; Reperfusion Injury

Topics: Animals; Cell Division; Cyclosporine; Immunosuppressive Agents; Kidney; Kidney Transplantation; Leukocytes; Mycophenolic Acid; Neutrophils; Proliferating Cell Nuclear Antigen; Rats; Rats, Inbred Lew; Regeneration; Reperfusion Injury

Mycophenolate mofetil (MMF) is a new immunosuppressive agent which has been used successfully after kidney and heart transplantation. Experience with MMF after liver transplantation is still limited. In particular, there is no information about influence on ischemia-reperfusion injury (IRI). Therefore, the aim of this investigation was to assess the effects of mycophenolic acid (MPA), the pharmacologically active metabolite of MMF, in the cold-preserved or normal rat liver. Livers of male Sprague-Dawley rats were subjected to cold ischemia in University of Wisconsin (UW) solution (24 h, 4 degrees C) and reperfused for 2 h in the absence or presence of MPA (100 microg/ml, n=5-6 each). Another group received MPA pretreatment for 20 min prior to ischemia ( n=7). In further experiments, livers were perfused with a bile salt-free Krebs-Henseleit buffer in a continuous fashion (controls, n=5). MPA was infused from 20-40 min after starting perfusion in therapeutic concentrations (5 microg/ml, 10 microg/ml, 40 microg/ml, and 100 microg/ml; n=3-6 each). There was no significant influence of MPA on portal pressure nor on postischemic efflux rates of LDH. MPA pretreatment resulted in a significant improvement of bile flow during reperfusion (0.32+/-0.05 microl/min x g liver) compared with controls (0.17+/-0.04 microl/min x g liver, mean+/-SEM). In contrast, postischemic bile flow was not influenced by continuous administration of MPA during the reperfusion period only (0.18+/-0.07 microl/min x g liver). In continuously perfused livers, MPA increased bile salt-independent bile flow (1.00+/-0.06 microl/min x g liver) in a dose-dependent manner, reaching half-maximal effects around 5 microg/ml (1.66+/-0.15 microl/min x g liver) and maximal effects at 40 microg/ml (2.61+/-0.28 microl/min x g liver). In conclusion, neither preischemic nor postischemic administration of MPA influences IRI to hepatocytes significantly after hypothermic liver preservation in UW solution. In contrast to other immunosuppressive agents, MPA exhibits strong choleretic effects, which are related to a stimulation of bile salt-independent bile formation.

Topics: Animals; Bile; Cold Temperature; Immunosuppressive Agents; Ischemia; L-Lactate Dehydrogenase; Liver; Male; Mycophenolic Acid; Organ Preservation; Perfusion; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Recent animal data suggest that inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) plays an important role in the pathogenesis of renal ischaemia-reperfusion injury (IRI) and that inhibition of iNOS ameliorates IRI. Mycophenolate mofetil (MMF), a lymphocyte selective anti-proliferative agent, has been shown to inhibit NO production in vitro. The aim of this study is to evaluate the effect of MMF on NO production and iNOS gene expression in vivo during renal IRI.. Renal IRI was induced by clamping the left renal pedicle of male BALB/c mice for 30 min, followed by 15 min of reperfusion. The mice received placebo or MMF at 40, 80 or 120 mg/kg/day by oral gavage for 5 days before the operation. Sham-operated mice served as the operation control. The amount of NO produced and the level of iNOS gene expression in the kidney tissue during IRI was assessed by spin trapping electron paramagnetic resonance (EPR) spectroscopy and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) respectively.. In the sham-operated kidneys, only low levels of NO and iNOS mRNA were detected. In mice with renal IRI, the amount of NO detected was significantly increased, which was reduced in a dose dependent fashion by pre-treatment with MMF. Pre-treatment with MMF also substantially reduced iNOS gene expression in the kidney tissue.. We conclude that pre-treatment with MMF inhibits the production of NO and the induction of iNOS gene expression in the kidney during IRI. These results suggest that MMF might have the potential to ameliorate renal IRI.

Topics: Animals; Gene Expression; Ischemia; Male; Mice; Mice, Inbred BALB C; Mycophenolic Acid; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Renal Circulation; Reperfusion Injury

Topics: Animals; Dogs; Graft Rejection; Heart Transplantation; Immunosuppressive Agents; Mycophenolic Acid; Rats; Reperfusion Injury; Tissue Donors; Transplantation Immunology

Mycophenolic acid, the active metabolite of mycophenolate mofetil, inhibits the glycosylation of cell membrane glycoproteins. We hypothesized that impaired glycosylation of cell adhesion molecules on endothelial cells in vivo results in decreased susceptibility to inflammation or immunogenicity after allogeneic transplantation.. The expression of mannose residues on cultured rat endothelial cells was examined after stimulation with interleukin 1 in the presence or absence of mycophenolic acid using labeled Galanthus nivalis agglutinin. The in vitro adhesion of blood leukocytes to heart tissue was examined using peripheral blood leukocytes of recipient origin and sections of donor heart tissue exposed to ischemia-reperfusion injury after pretreatment with vehicle or mycophenolic mofetil. (LEWxBN)F1 donor rats were treated with 20 or 60 mg/kg/day of mycophenolate mofetil for 1 or 2 weeks followed by transplantation of the heart into Lewis recipients after storage in heparin-containing normal saline for either 10 min at 4 degrees C or 120 min at room temperature.. Endothelial cells stimulated in vitro with interleukin 1 showed an increase in a population of strongly mannose-positive cells, which was prevented by the addition of mycophenolic acid during the culture. The in vitro adhesion of peripheral blood leukocytes to cardiac tissue sections exposed to prolonged storage and reperfusion was significantly less if the donor had been treated with mycophenolate mofetil. Treatment of cardiac graft donors with mycophenolate mofetil protected the graft against early graft failure after prolonged storage at room temperature, because the mean graft survival was 9.4+/-0.6 days for grafts that came from donors treated with mycophenolate mofetil versus 1.2+/-0.9 days (P<0.05) for grafts that came from vehicle-treated donors. Donor pretreatment with mycophenolate mofetil did not affect the survival time of heart grafts transplanted after 15 min of standard cold storage or the survival of grafts transplanted into presensitized recipients.. Donor treatment with mycophenolate mofetil protects cardiac grafts against primary nonfunction after prolonged tepid storage, which may be related to the inhibition of glycosylation of cell adhesion molecules involved in ischemia-reperfusion injury.

Topics: Animals; Cell Adhesion; Galanthus; Graft Rejection; Heart Transplantation; Immunosuppressive Agents; Leukocytes; Male; Mycophenolic Acid; Rats; Rats, Inbred BN; Rats, Inbred Lew; Reperfusion Injury; Tissue Donors; Transplantation Immunology

Topics: Animals; Curcumin; Drug Synergism; Flavonoids; Graft Rejection; Immunosuppressive Agents; Ischemia; Kidney; Male; Mycophenolic Acid; Quercetin; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Skin Transplantation