Prevention of early renal injury by mycophenolate mofetil and its mechanism in experimental diabetes

Bioinformatics Analysis Reveals Crosstalk Among Platelets, Immune Cells, and the Glomerulus That May Play an Important Role in the Development of Diabetic Nephropathy

Diabetic nephropathy (DN) is the main cause of end stage renal disease (ESRD). Glomerulus damage is one of the primary pathological changes in DN. To reveal the gene expression alteration in the glomerulus involved in DN development, we screened the Gene Expression Omnibus (GEO) database up to December 2020. Eleven gene expression datasets about gene expression of the human DN glomerulus and its control were downloaded for further bioinformatics analysis. By using R language, all expression data were extracted and were further cross-platform normalized by Shambhala. Differentially expressed genes (DEGs) were identified by Student's t-test coupled with false discovery rate (FDR) (P < 0.05) and fold change (FC) ≥1.5. DEGs were further analyzed by the Database for Annotation, Visualization, and Integrated Discovery (DAVID) to enrich the Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. We further constructed a protein-protein interaction (PPI) network of DEGs to identify the core genes. We used digital cytometry software CIBERSORTx to analyze the infiltration of immune cells in DN. A total of 578 genes were identified as DEGs in this study. Thirteen were identified as core genes, in which LYZ, LUM, and THBS2 were seldom linked with DN. Based on the result of GO, KEGG enrichment, and CIBERSORTx immune cells infiltration analysis, we hypothesize that positive feedback may form among the glomerulus, platelets, and immune cells. This vicious cycle may damage the glomerulus persistently even after the initial high glucose damage was removed. Studying the genes and pathway reported in this study may shed light on new knowledge of DN pathogenesis.

Betulinic acid reduces the complications of autoimmune diabetes on the body and kidney through effecting on inflammatory cytokines in C57BL/6 mice

Autoimmune diabetes is one of the most common metabolic diseases with increasing prevalence in the past decades in which pancreatic Langerhans β cells are destroyed and lead to lack of insulin due to increased blood sugar. One of the consequences of diabetes is glomerular disease of the kidney, also called diabetes nephropathy. Different studies have been carried out on the effects of triterpenoids and their medicinal effects on diabetes mellitus. betulinic acid, a pentacyclic triterpenoid of Terpenes, is found in bushes and trees. Its medical effects are also approved by many studies. In this survey, we studied the effect of betulinic acid on diabetic inbred C57BL/6 male mice. They were randomly divided to three groups. Group A: Consisted of healthy mice which received citrate buffer. Group B: Diabetic mice without any treatment and group C: Treated diabetic mice with betulinic acid. The level of blood insulin level, fasting blood glucose, C-peptide, TNF-α, IFN-γ, and IL-1 cytokines were measured and pathologic studies of the kidney were performed. The results showed that betulinic acid could increase insulin and C-peptide, and decrease fasting blood sugar, kidney lesions and TNF-α, IFN-γ, IL-1 in the treated groups. The differences were significant except for IL-1. Betulinic acid through reduction of inflammatory cytokines could have positive effects on inflammatory and autoimmune disease including autoimmune diabetes.

The influence of exposure to immunosuppressive treatment during pregnancy on renal function and rate of apoptosis in native kidneys of female Wistar rats

Pregnancy puts a significant additional strain on kidneys. The aim of our study was to investigate the impact of immunosuppressive drugs on changes in native kidneys in female Wistar rats after exposure during pregnancy. The study was conducted on 32 dams, subjected to immunosuppressive regimens commonly used in the therapy of human kidney transplant recipients (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; cyclosporine A, everolimus and prednisone). The animals received drugs for 2 weeks before pregnancy and during 3 weeks of pregnancy. In all treated dams lower body weight (but not kidney mass) and alterations in serum sodium and chloride ions were found; serum creatinine concentration was increased in dams treated with cyclosporine A, everolimus and prednisone. All treatment groups of dams showed increased apoptosis in the distal tubules. In histological examination the changed intensity of acidophilic or basophilic cytoplasm of epithelial cells was found in kidneys of rats treated with calcineurin inhibitors, mycophenolate mofetil and prednisone. All immunosuppressive regimens caused abnormalities affecting nephron tubules. Regimens containing calcineurin inhibitors and mycophenolate mofetil caused higher rate of apoptosis and more pronounced histopathological changes. Regimen based on everolimus despite the lower rate of apoptosis in the proximal tubules and lower accumulation of kidney injury markers revealed higher serum creatinine concentration. Thus, interpretation which combination of drugs is better or worse for long-lasting functioning of kidneys in pregnant females requires further studies.

Value of the combined examination of Cys-C and HbA1c for diagnosis of early renal injury in pediatric diabetes

The objective of the present study was to evaluate the combined application of measuring cystatin C (Cys-C) and hemoglobin A1c (HbA1c) levels for early renal injury in pediatric patients with type 2 diabetes. A total of 130 children with type 2 diabetes admitted to our hospital from May 2013 to July 2015 were selected. Patients were divided according to whether there was complication of renal injury. In group A (n=65), the patients had renal injury and in group B (n=65), the patients did not have renal injury. The levels of Cys-C and HbA1c in the two groups were examined. The results showed that the levels of Cys-C and HbA1c of patients in group A were significantly higher than those in group B (P<0.05), and the positive rate of the combined examination of Cys-C and HbA1c in group A was 92.3%, and was higher than that of the individual examinations of either Cys-C or HbA1c (P<0.05). The Spearman's correlation coefficient analysis was applied to group B and showed that Cys-C was positively correlated with HbA1c (r=0.842, P<0.05). From analysis of the receiver operating characteristic curves, the combined examination of Cys-C and HbA1c surpassed the individual examinations of Cys-C or HbA1c in sensitivity and specificity (P<0.05). In conclusion, the positive detection rate of early renal injury was significantly increased by the combined examination of Cys-C and HbA1c in pediatric patients with type 2 diabetes, which is beneficial for early identification and diagnosis of this diseases and is worthy of clinical application.

Mycophenolate mofetil as an immunomodulatory silver bullet in atherogenesis?

Atherosclerotic vascular disease is a chronic disorder of the vasculature with a substantial impact on society. Although the availability of statins has represented an unparalleled improvement in the treatment of patients with such cardiovascular disease, even more effective measures are required to reverse this disorder with a continuously growing incidence. The classification of atherosclerosis as an inflammatory disorder has prompted the hypothesis that immunomodulation could comprise a novel anti-atherosclerotic strategy. Mycophenolate mofetil (MMF) has various anti-atherogenic effects on major components of the atherosclerotic plaque such as T-lymphocytes, monocytes/macrophages and the endothelium. MMF can inhibit leukocyte recruitment to the subendothelium and the subsequent reduced activation of leukocytes will translate into attenuation of subendothelial crosstalk between T-cells and macrophages. This cascade of events will interrupt the self-perpetuating pro-inflammatory environment within the arterial wall, the hallmark of atherosclerotic vascular disease.

Effect of Immunosuppressive Therapy on Proteinogram in Rats

BACKGROUND It has been observed that the use of immunosuppressive drugs in patients after transplantation of vascularized organs may be associated with changes in the concentration of certain fractions of plasma proteins. The concentration of these proteins was correlated with an increased risk of occurrence of stage 3 chronic kidney disease (CKD). This article examines the effect of the most commonly used immunosuppressive drugs on the concentration of plasma proteins in Wistar rats. MATERIAL AND METHODS The study involved 36 rats grouped according to the immunosuppressive regimen used (tacrolimus, mycophenolate mofetil, cyclosporine A, rapamycin, and prednisone). The rats in all study groups were treated with a 3-drug protocol for 6 months. The treatment dose was adjusted based on available data in the literature. No drugs were administered to the control group. The rats were sacrificed and blood samples collected to determine the concentration of plasma proteins using electrophoresis technique. RESULTS Statistically significant differences were observed between protein concentrations within the studied groups. The differences related to the proteins with masses of 195 kDa, 170 kDa, 103 kDa, and 58 kDa. CONCLUSIONS (1) Immunosuppressive drugs caused changes in the proteinogram of plasma proteins. (2) The strongest effect on rat plasma proteins was exerted by a regimen based on rapamycin. Intermediate, weak, and weakest effects were observed in regimens based on cyclosporine A, tacrolimus, and mycophenolate mofetil, respectively.

Anti-Inflammatory Therapy Modulates Nrf2-Keap1 in Kidney from Rats with Diabetes

This study addressed the relationship of proinflammatory cytokines and Nrf2-Keap1 system in diabetic nephropathy. The experimental groups were control, diabetic, and diabetic treated with mycophenolate mofetil (MMF). The renal function, proinflammatory and profibrotic cytokines, oxidative stress, morphology, and nephrin expression were assessed. Diabetic group showed impaired renal function in association with oxidative stress and decreased Nrf2 nuclear translocation. These results were associated with increased mesangial matrix index, interstitial fibrosis, and increased nephrin expression in cortex and urine excretion. Additionally, interleukin-1β, IL-6, and transforming growth factor-β1 were increased in plasma and kidney. MMF treatment conserved renal function, prevented renal structural alterations, and partially prevented the proinflammatory and profibrotic cytokines overexpression. Despite that MMF treatment induced nephrin overexpression in renal tissue, preventing its urinary loss. MMF salutary effects were associated with a partial prevention of oxidative stress, increased Nrf2 nuclear translocation, and conservation of antioxidant enzymes in renal tissue. In conclusion, our results confirm that inflammation is a key factor in the progression of diabetic nephropathy and suggest that treatment with MMF protects the kidney by an antioxidant mechanism, possibly regulated at least in part by the Nrf2/Keap1 system, in addition to its well-known anti-inflammatory effects.

Management of immunosuppressant agents following liver transplantation: Less is more

Immunosuppression in organ transplantation was revolutionary for its time, but technological and population changes cast new light on its use. First, metabolic syndrome (MS) is increasing as a public health issue, concomitantly increasing as an issue for post-orthotopic liver transplantation patients; yet the medications regularly used for immunosuppression contribute to dysfunctional metabolism. Current mainstay immunosuppression involves the use of calcineurin inhibitors; these are potent, but nonspecifically disrupt intracellular signaling in such a way as to exacerbate the impact of MS on the liver. Second, the impacts of acute cellular rejection and malignancy are reviewed in terms of their severity and possible interactions with immunosuppressive medications. Finally, immunosuppressive agents must be considered in terms of new developments in hepatitis C virus treatment, which undercut what used to be inevitable viral recurrence. Overall, while traditional immunosuppressive agents remain the most used, the specific side-effect profiles of all immunosuppressants must be weighed in light of the individual patient.

Renal Protection by Genetic Deletion of the Atypical Chemokine Receptor ACKR2 in Diabetic OVE Mice

In diabetic nephropathy (DN) proinflammatory chemokines and leukocyte infiltration correlate with tubulointerstitial injury and declining renal function. The atypical chemokine receptor ACKR2 is a chemokine scavenger receptor which binds and sequesters many inflammatory CC chemokines but does not transduce typical G-protein mediated signaling events. ACKR2 is known to regulate diverse inflammatory diseases but its role in DN has not been tested. In this study, we utilized ACKR2(-/-) mice to test whether ACKR2 elimination alters progression of diabetic kidney disease. Elimination of ACKR2 greatly reduced DN in OVE26 mice, an established DN model. Albuminuria was significantly lower at 2, 4, and 6 months of age. ACKR2 deletion did not affect diabetic blood glucose levels but significantly decreased parameters of renal inflammation including leukocyte infiltration and fibrosis. Activation of pathways that increase inflammatory gene expression was attenuated. Human biopsies stained with ACKR2 antibody revealed increased staining in diabetic kidney, especially in some tubule and interstitial cells. The results demonstrate a significant interaction between diabetes and ACKR2 protein in the kidney. Unexpectedly, ACKR2 deletion reduced renal inflammation in diabetes and the ultimate response was a high degree of protection from diabetic nephropathy.

Mycophenolate Mofetil Ameliorates Diabetic Nephropathy in db/db Mice

Chronic low-grade inflammation is an important factor in the pathogenesis of diabetic complication. Mycophenolate mofetil (MMF) has an anti-inflammatory effect, inhibiting lymphocyte proliferation. Previous studies showed attenuation of diabetic nephropathy with MMF, but the underlying mechanisms were unclear. This study aimed to identify the effect of MMF on diabetic nephropathy and investigate its action mechanisms in type 2 diabetic mice model. Eight-week-old db/db and control mice (db/m mice) received vehicle or MMF at a dose of 30 mg/kg/day for 12 weeks. MMF-treated diabetic mice showed decreased albuminuria, attenuated mesangial expansion, and profibrotic mRNA expressions despite the high glucose level. The number of infiltrated CD4⁺ and CD8⁺ T cells in the kidney was significantly decreased in MMF-treated db/db mice and it resulted in attenuating elevated intrarenal TNF-α and IL-17. The renal chemokines expression and macrophages infiltration were also attenuated by MMF treatment. The decreased expression of glomerular nephrin and WT1 was recovered with MMF treatment. MMF prevented the progression of diabetic nephropathy in db/db mice independent of glycemic control. These results suggest that the effects of MMF in diabetic nephropathy are mediated by CD4⁺ T cell regulation and related cytokines.

Urinary monocyte chemoattractant protein-1 and vitamin D-binding protein as biomarkers for early detection of diabetic nephropathy in type 2 diabetes mellitus

Diabetic nephropathy is a serious complication of both type 1 and type 2 diabetes and, unless arrested, leads to end-stage renal disease. Therefore, early prediction and detection of DN would greatly benefit the disease management and delay its progression. The aim of this study is to evaluate the levels of urinary monocyte chemoattractant protein-1 (uMCP-1) and urinary vitamin D-binding protein (uVDBP) in type 2 diabetic patients with different degrees of diabetic nephropathy (DN) and to assess the value of uMCP-1 and uVDBP in the early detection of DN. Seventy-five type 2 diabetic patients with normoalbuminuria (n = 25), microalbuminuria (n = 25), macroalbuminuria (n = 25), and 25 healthy controls were included in this study. Urinary MCP-1 and VDBP levels were evaluated by enzyme-linked immunosorbent assay. A significant elevation in the uMCP-1 and uVDBP levels was found in macroalbuminuric (p < 0.001) and microalbuminuric (p < 0.01) diabetic patients compared to that in normoalbuminuric diabetic patients and control subjects (p < 0.001). Correlation study revealed that both uMCP-1 and uVDBP were significantly positively correlated to urinary albumin/creatinine ratio (r = 0.968, p < 0.001 and r = 0.973, p < 0.001, respectively), serum urea (r = 0.461, p = 0.001 and r = 0.456, p = 0.002, respectively), and serum creatinine (r = 0.475, p = 0.001 and r = 0.448, p = 0.004, respectively) and significantly inversely correlated to glomerular filtration rate (r = -0.983, p < 0.001 and r = -0.988, p < 0.001, respectively). Receiver operating characteristic (ROC) curve analysis of uMCP-1 and uVDBP levels for early diagnosis and detection of DN revealed that the cut-off value of uMCP-1 was 110 pg/mg with 92% sensitivity and 100% specificity; whereas, the cut-off value of uVDBP was 550 ng/mg with 96% sensitivity and 84% specificity. The findings of the present study suggest that uMCP-1 and uVDBP may be considered as novel potential diagnostic biomarkers for the early detection of diabetic nephropathy.

Renal injury induced in alloxan diabetic rats. Role of Mycophenolate Mofetil as therapeutic agent

BACKGROUND

Renal injury may develop in uncontrolled chronic hyperglycemia due to increased oxidative stress and release of pro-inflammatory mediators, leading to diabetic complications.

METHODS

Mycophenolate Mofetil (MMF) is an immunosuppressant drug, an inhibitor of inosine monophosphate dehydrogenase (IMPDH), relevant to inflammation processes. MMF effect was tested in alloxan-diabetic rats on selected parameters like oxidative stress, gene expression of tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1), in relation to microalbuminuria and renal function.

RESULTS

We found that the onset of microalbuminuria preceded the increase in serum glucose after alloxan treatment. Gene expression of TNF-α and TGF-β1 showed gradual increase after one and two weeks of alloxan administration as compared to the normal group. MMF administration decreased the gene expression of TNF-α and TGF-β1 in kidney tissues, serum glucose, fructosamine, urea, creatinine, C-reactive protein, malondialdehyde, urinary microalbumin and total protein. Histological examination of kidney tissues showed significant improvement in MMF treated rats as compared to diabetic control.

CONCLUSIONS

MMF modulated renal injury of alloxan diabetic rats. Collective data may support its therapeutic effect but further clinical trials may be requested.

Sitagliptin prevents inflammation and apoptotic cell death in the kidney of type 2 diabetic animals

This study aimed to evaluate the efficacy of sitagliptin, a dipeptidyl peptidase IV (DPP-IV) inhibitor, in preventing the deleterious effects of diabetes on the kidney in an animal model of type 2 diabetes mellitus; the Zucker diabetic fatty (ZDF) rat: 20-week-old rats were treated with sitagliptin (10 mg/kg bw/day) during 6 weeks. Glycaemia and blood HbA1c levels were monitored, as well as kidney function and lesions. Kidney mRNA and/or protein content/distribution of DPP-IV, GLP-1, GLP-1R, TNF-α, IL-1β, BAX, Bcl-2, and Bid were evaluated by RT-PCR and/or western blotting/immunohistochemistry. Sitagliptin treatment improved glycaemic control, as reflected by the significantly reduced levels of glycaemia and HbA1c (by about 22.5% and 1.2%, resp.) and ameliorated tubulointerstitial and glomerular lesions. Sitagliptin prevented the diabetes-induced increase in DPP-IV levels and the decrease in GLP-1 levels in kidney. Sitagliptin increased colocalization of GLP-1 and GLP-1R in the diabetic kidney. Sitagliptin also decreased IL-1β and TNF-α levels, as well as, prevented the increase of BAX/Bcl-2 ratio, Bid protein levels, and TUNEL-positive cells which indicates protective effects against inflammation and proapoptotic state in the kidney of diabetic rats, respectively. In conclusion, sitagliptin might have a major role in preventing diabetic nephropathy evolution due to anti-inflammatory and antiapoptotic properties.

Pyridoxamine, an inhibitor of protein glycation, in relation to microalbuminuria and proinflammatory cytokines in experimental diabetic nephropathy

Diabetic nephropathy (DN) is one of the major complications that develop as consequence of chronic and uncontrolled hyperglycaemia. Hyperglycaemia initiates various processes, one of which is protein glycation, leading to the formation of advanced glycation end products. Alteration of intracellular signalling, gene expression, release of proinflammatory molecules and free radicals are examples of such changes and they contribute to the initiation of diabetic complications. In the current manuscript, we studied the effect of pyridoxamine (PM) on protein glycation, oxidative stress, interleukin-1α (IL-1α), IL-6, C-reactive protein (CRP), gene expression of tumour necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) in relation to microalbuminuria and kidney functions in a model of alloxan-induced diabetic rats. We have observed that onset of microalbuminuria has preceded the gradual increase of blood sugar level in diabetic rats. In diabetic rats, gene expression of TNF-α and TGF-β1 recorded a gradual increase and marked increase was observed after one and two weeks of alloxan administration, in comparison with normal rats. PM induced significant decrease in kidney malondialdehyde content and the gene expression of TNF-α and TGF-β1, in addition to levels of serum glucose, fructosamine, urea, creatinine, IL-1α, IL-6, CRP and urine microalbumin. Histopathological examination of kidney tissues showed certain improvements as compared with diabetic control. In conclusion, our results may provide a supporting evidence for the therapeutic benefit of PM in DN.

Mycophenolate mofetil and valsartan inhibit podocyte apoptosis in streptozotocin-induced diabetic rats

AIM

To investigate the effects of mycophenolate mofetil on apoptosis and the expression of Bax and Bcl-2 of podocytes in rats with diabetic nephropathy.

METHODS

A total of 40 male rats were randomly divided into two groups: healthy control group (NC, n = 8) and diabetic nephropathy group (DN, n = 32). The diabetic rat models were induced by streptozotocin, which was injected intraperitoneally. After the DN model was established successfully, the DN group was subdivided into four groups: (1) group treated with the dissolvent (DN), (2) group treated with mycophenolate mofetil (DN + M), (3) group treated with valsartan (DN + V) and (4) group treated with mycophenolate mofetil and valsartan (DN + MV). After 16 weeks of treatment, kidney and body weight, urinary protein level and serum glucose were measured. Histomorphology of renal tissue was observed by an optical microscope. Apoptosis of podocytes was determined by transferase-mediated dUTP nick-end labeling (TUNEL) test. The expression of nephrin and Wilms' tumor suppressor gene (WT1) were detected by immunohistochemistry and real-time PCR, and the protein expression of Bax and Bcl-2 were examined by Western blot.

RESULTS

The mRNA and protein expression of nephrin and WT1 were both downregulated. The apoptosis rate, the expression of Bax, caspase-3 activity and cleavage increased, while the expression of Bcl-2 decreased in the DN group compared with the NC group. However, they were all improved in the groups treated with either mycophenolate mofetil or valsartan.

CONCLUSION

Mycophenolate mofetil can protect renal function by increasing Bcl-2 expression and decreasing Bax expression and podocyte apoptosis rate, thereby reducing proteinuria.

Monocyte Chemoattractant Protein 1 (MCP-1) in obesity and diabetes

Monocyte Chemoattractant Protein-1 (MCP-1) is the first discovered and most extensively studied CC chemokine, and the amount of studies on its role in the etiologies of obesity- and diabetes-related diseases have increased exponentially during the past two decades. This review attempted to provide a panoramic perspective of the history, regulatory mechanisms, functions, and therapeutic strategies of this chemokine. The highlights of this review include the roles of MCP-1 in the development of obesity, diabetes, cardiovascular diseases, insulitis, diabetic nephropathy, and diabetic retinopathy. Therapies that specifically or non-specifically inhibit MCP-1 overproduction have been summarized.

In rat renal fibroblasts, mycophenolic acid inhibits proliferation and production of the chemokine CCL2, stimulated by tumour necrosis factor-alpha

BACKGROUND AND PURPOSE

Renal fibroblasts play a pivotal role in the development of tubulointerstitial fibrosis, a condition highly predictive of progression towards end-stage renal disease. The present study investigated the anti-mitogenic and anti-inflammatory effects of an inhibitor of inosine monophosphate dehydrogenase, mycophenolic acid (MPA) and the mechanisms underlying its action in normal rat kidney fibroblasts (49F cells).

EXPERIMENTAL APPROACH

Proliferation of 49F cells was studied by tetrazole 3-(4, 5-dimethylthiazol-2-yl-)-2,5-diphenyltetrazolium bromide (MTT) test, bromodeoxyuridine incorporation and flow cytometry. The cyclins, tumour suppressor genes and phospho-mitogen-activated protein kinases (MAPKs) were semiquantified by immunoblotting. Apoptosis was measured by quantifying the fragmented DNA and the activity of caspase 3. The monocyte chemokine CCL2 was measured by ELISA. The mRNA expression of CCL2 was measured by real-time PCR.

KEY RESULTS

Mycophenolic acid dose-dependently inhibited steady-state proliferation of 49F cells by up-regulation of p21, p27 and p53, in association with a decrease in cyclins D2 and E. Treatment with MPA also triggered apoptosis of 49F cells by activating the caspase 3 cascade. Furthermore, MPA attenuated tumour necrosis factor-alpha-induced CCL2 expression through down-regulation of p38 MAPK, but not that of ERK1/2 or JNK.

CONCLUSIONS AND IMPLICATIONS

The anti-mitogenic and anti-inflammatory effects of MPA were mediated by up-regulation of cell cycle inhibitors and pro-apoptotic signals, and by suppression of p38 MAPK pathway respectively. This dual effect of MPA may form the rationale for animal or clinical trials for the treatment of fibrotic renal diseases.

The renal benefit of mycophenolate mofetil after liver transplantation

BACKGROUND

The risk and benefit of adding mycophenolate mofetil (MMF) to a standard immunosuppressive regimen at the time of liver transplantation (LT) is not well described.

METHODS

We performed a retrospective case-control analysis comparing one-yr outcomes of all LT recipients at our institution treated with post-operative tacrolimus (TAC), MMF, and steroids vs. TAC and steroids.

RESULTS

A total of 101 LT recipients (50:51 case:control) were analyzed. Despite more renal dysfunction at LT, the MMF + TAC group had similar serum creatinine (Cr) and glomerular filtration rate (GFR) as the TAC group one-yr post-LT. In this time period, Cr decreased (1.57-1.22 mg/dL, p = 0.04) and GFR increased (57.5-65.1 mL/min per 1.73 m(2), p = 0.05) in the MMF + TAC group, while Cr increased (1.11-1.35, p < 0.01) and GFR declined (73.5-60.1, p < 0.001) in the TAC group. These findings occurred without a difference in absolute rejection episodes, hospitalizations, infections, deaths, or time to above events (p > 0.05). Subgroup analysis of patients stratified by pre-transplant renal dysfunction (Cr ≥ 1.2 mg/dL) supported the previous. MMF was reasonably well tolerated with a low rate of discontinuation.

CONCLUSIONS

The use of adjunctive MMF immediately after LT may protect against calcineurin inhibitor nephrotoxicity, potentially without the need for dose reduction or increased risk of adverse events.

Effect of the inosine 5'-monophosphate dehydrogenase inhibitor BMS-566419 on renal fibrosis in unilateral ureteral obstruction in rats

Chronic allograft nephropathy (CAN) is a major cause of late allograft loss. One morphological characteristic of CAN is renal interstitial fibrosis. Mycophenolate mofetil (MMF), the inosine 5'-monophosphate dehydrogenase (IMPDH) inhibitor, has been reported to attenuate the progression of renal interstitial fibrosis. However, the question of whether the newly synthesized IMPDH inhibitors with structures different from MMF have an antifibrotic effect remains unanswered. We evaluated the antifibrotic effects of BMS-566419, a chemically synthesized IMPDH inhibitor, using an experimental rat model, unilateral ureteral obstruction (UUO), in comparison with those of MMF. Expression levels of monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-beta1 (TGF-β1), which play important roles in UUO-induced renal fibrosis, were also investigated to determine the mechanism by which BMS-566419 affects the progression of renal fibrosis. After 14 days of UUO, interstitial fibrosis was frequently observed in the renal cortex of rats administered vehicle control. BMS-566419 by oral administration showed a significant and dose-dependent suppressive effect on UUO-induced renal fibrosis in histopathological experiments. BMS-566419 treatment also decreased collagen content, as indicated by hydroxyproline concentration, and the expression of collagen type 1 mRNA. BMS-566419 also decreased the expression of mRNA for both MCP-1 and TGF-β1. The antifibrotic effects of treatment with BMS-566419 at 60 mg/kg seemed comparable to those with MMF at 40 mg/kg. These results suggest that BMS-566419 and other chemically synthesized IMPDH inhibitors have beneficial pharmacological effects similar to those of MMF, and are potential pharmaceutical candidates in the treatment of fibrotic renal disease, including CAN.

Relationship between oxidative stress and inflammatory cytokines in diabetic nephropathy

The prevalence of diabetes has dramatically increased worldwide due to the vast increase in the obesity rate. Diabetic nephropathy is one of the major complications of type 1 and type 2 diabetes and it is currently the leading cause of end-stage renal disease. Hyperglycemia is the driving force for the development of diabetic nephropathy. It is well known that hyperglycemia increases the production of free radicals resulting in oxidative stress. While increases in oxidative stress have been shown to contribute to the development and progression of diabetic nephropathy, the mechanisms by which this occurs are still being investigated. Historically, diabetes was not thought to be an immune disease; however, there is increasing evidence supporting a role for inflammation in type 1 and type 2 diabetes. Inflammatory cells, cytokines, and profibrotic growth factors including transforming growth factor-β (TGF-β), monocyte chemoattractant protein-1 (MCP-1), connective tissue growth factor (CTGF), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-18 (IL-18), and cell adhesion molecules (CAMs) have all been implicated in the pathogenesis of diabetic nephropathy via increased vascular inflammation and fibrosis. The stimulus for the increase in inflammation in diabetes is still under investigation; however, reactive oxygen species are a primary candidate. Thus, targeting oxidative stress-inflammatory cytokine signaling could improve therapeutic options for diabetic nephropathy. The current review will focus on understanding the relationship between oxidative stress and inflammatory cytokines in diabetic nephropathy to help elucidate the question of which comes first in the progression of diabetic nephropathy, oxidative stress, or inflammation.

The accumulated experience with the use of mycophenolate mofetil in primary glomerulonephritis

IMPORTANCE OF THE FIELD

The use of mycophenolate mofetil (MMF) has been extended from renal transplantation to the treatment of glomerulonephritis. MMF has been used in patients with steroid- and ciclosporin A (CsA)-dependent or -resistant idiopathic nephrotic syndrome and in patients with deteriorating renal function or adverse reactions to other drugs. MMF has been also used in patients with membranous and IgA nephropathy after failure of other regimens as well as initial treatment.

AREAS COVERED IN THIS REVIEW

The rationale of MMF treatment in primary glomerulonephritis is based in its antifibrotic and antiproteinuric effects. The mechanism of action is described; the results of cohort and randomized trials in minimal change disease, focal segmental glomerulosclerosis, idiopathic membranous nephropathy and IgA nephropathy are presented along with the adverse reactions profile and the expert opinion.

WHAT THE READER WILL GAIN

This is an up-to-date review providing insight on this novel agent that is increasingly used in the therapeutics of primary glomerulonephritis.

TAKE HOME MESSAGE

Although the results are conflicting, MMF seems to be effective at least in some patients, who do not respond to corticosteroids, ciclosporin or cytotoxic drugs. However, the experience with MMF in primary glomerulonephritis is limited and further research is required in order to establish MMF in the treatment of patients with glomerular disease.

Preventive effects of syngeneic bone marrow transplantation on diabetic nephropathy in mice

Treatment with autologous bone marrow transplantation (ABMT) can change the natural history of diabetes in patients with new-onset Type 1 diabetes (T1D). Effects of syngeneic bone marrow transplantation (syn-BMT) on diabetic nephropathy were studied in streptozotocin-induced diabetic mice. Diabetic mice received sibling's bone marrow on days 3, 10, 20, or 40 after T1D onset, respectively. Renal pathology, levels of oxidative stress, and the expressions of angiotensinogen (AGT), monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor beta 1 (Tgf-beta1) mRNA were investigated. Treatment with syn-BMT when disease was early-onset reduced mesangial area expansion and kidney enlargement; besides, if it is given on day 10, syn-BMT attenuated glomerular hypertrophy. Oxidative stress factors such as catalase (CAT) and superoxide radical anion O(2-) (O(2-)) were markedly maintained by syn-BMT compared to mice without treatment. In diabetic mice without treatment, renal AGT and MCP-1 mRNA were increased, while they were effectively suppressed by syn-BMT. But it showed no changes or even increment in Tgf-beta1 mRNA after syn-BMT. Syn-BMT, if applied when disease was early-onset, ameliorated diabetic renal injury. These preventive effects could be partly via maintaining oxidative stress and expression of AGT and MCP-1 in kidney in streptozotocin-diabetic mice.

Pathogenic perspectives for the role of inflammation in diabetic nephropathy

Diabetes and its complications have become a public health problem. One of the most important complications is diabetic nephropathy, which is nowadays the main cause of chronic renal failure. In spite of our greater understanding of this complication, the intimate mechanisms leading to the development and progression of renal injury are not well understood. New perspectives in activated innate immunity and inflammation appear to be relevant factors in the pathogenesis of diabetes. Moreover, different inflammatory molecules, including adipokines, Toll-like receptors, chemokines, adhesion molecules and pro-inflammatory cytokines, may be critical factors in the development of microvascular diabetic complications, including nephropathy. This new pathogenic perspective leads to important therapeutic considerations, with new pathogenic pathways becoming important therapeutic targets that can be translated into clinical treatments for diabetic nephropathy.

Renoprotective effect of total glucosides of paeony (TGP) and its mechanism in experimental diabetes

Total glucosides of paeony (TGP), extracted from the root of Paeonia lactiflora pall, has been shown to have ant-inflammatory and antioxidative actions. The aims of this study were to elucidate the renoprotective effect of TGP and its mechanism in experimental diabetes. Streptozotocin-induced diabetic rats were treated with TGP for 8 weeks. Treatment with TGP at 50, 100, and 200 mg/kg significantly lowered 24-h urinary albumin excretion rate in diabetic rats. TGP treatment in all doses markedly attenuated glomerular volume, and treatment with TGP at 100 and 200 mg/kg markedly reduced indices for tubulointerstitial injury in diabetic rats. Western blot analysis showed that the expressions of 1 alpha (IV) collagen, intercellular adhesion molecule (ICAM)-1, interleukin (IL)-1, tumor necrosis factor (TNF)-alpha, NF-kappaB p65, and 3-nitrotyrosine (3-NT) protein were increased in the kidneys of diabetic rats; the increases in these proteins were all dose-dependently and significantly inhibited by TGP treatment. The expression of nephrin protein was significantly reduced in the kidneys from diabetic rats and markedly increased by TGP treatment. The expression of transforming growth factor (TGF)-beta1 protein in the kidney was also significantly increased in diabetic rats, which was significantly inhibited by treatment with TGP at all doses. Our data suggest that TGP treatment ameliorates early renal injury via the inhibition of expression of ICAM-1, IL-1, TNF-alpha, and 3-NT in the kidneys of diabetic rats.

Nephrin and podocin loss is prevented by mycophenolate mofetil in early experimental diabetic nephropathy

Several works in the setting of early experimental diabetic nephropathy using anti-inflammatory drugs, such as mycophenolate mofetil (MMF), have shown that prevention of the development or amelioration of renal injury including proteinuria. The exact mechanisms by which anti-inflammatory drugs lower the albuminuria have no still to clarify well. In this study, diabetes was induced by injection of streptozotocin after uninephrectomy. Rats were randomly divided into three groups: control group, diabetic group and diabetic group treated with MMF. Elevated 24h urinary albumin excretion rate was markedly attenuated by MMF treatment. In diabetic rats receiving no treatment, there were increase in ED-1+ cells in the glomeruli, which were effectively suppressed by MMF treatment. The expression of nephrin and podocin protein was reduced in the glomeruli from diabetic rats, and MMF treatment significantly increased the expression of nephrin and podocin. The expression of IL-1, TNF-alpha and 3-NT protein in the glomeruli were significantly increased in diabetic rats, which were all significantly inhibited by MMF treatment. Our results show that MMF could decrease urinary albumin excretion, which mechanism may be at least partly correlated with upregulated expression of nephrin and podocin in the glomeruli of diabetic rat.

Inflammation and diabetic nephropathy

Diabetic nephropathy has become the main cause of renal failure, but unfortunately the intimate mechanisms leading to the development and progression of renal injury are not yet fully known. Activated innate immunity and inflammation are relevant factors in the pathogenesis of diabetes. Moreover, different inflammatory molecules, including chemokines, adhesion molecules, and proinflammatory cytokines, may be critical factors in the development of microvascular diabetic complications, including nephropathy. This new pathogenic perspective leads to important therapeutic considerations, with new pathogenic pathways becoming important therapeutic targets that can be translated into clinical treatments for diabetic nephropathy.