Zhangfei Shou

Rapamycin Prevents Early Steps of the Development of Diabetic Nephropathy in Rats

Background/Aims: Recent studies suggested the involvement of the Akt/mammalian target of rapamycin (mTOR) pathway in the pathogenesis of diabetic nephropathy. The effect of mTOR blockade by rapamycin in diabetic nephropathy was investigated, but in vivo study of rapamycin treatment in the course of early diabetes is still insufficient. This study was designed to determine the therapeutic effects of rapamycin on diabetic nephropathy at an early stage. Methods: Diabetes was induced in Sprague-Dawley rats with streptozotocin, and rapamycin (1 mg/kg) was administered by daily gavage for 4 weeks. Renal structural changes and some factors involved in the early pathogenesis of diabetic nephropathy were tested. The activation level of the Akt/mTOR pathway was also determined. Results: Rapamycin treatment reduced albuminuria, glomerular enlargement, glomerular basement membrane thickening, renal macrophage recruitment, and levels of renal mRNA expression of proliferating cell nuclear antigen, transforming growth factor-β1, vascular endothelial growth factor, and monocyte chemoattractant protein-1 without change in blood glucose level and blood pressure in experimental diabetic rats. In addition, treatment with rapamycin also down-regulated the enhanced levels of renal p-Akt, phospho-p70S6 kinase, and phospho-ribosomal S6 protein in diabetic rats. Conclusions: Rapamycin treatment can prevent the early renal structural changes of diabetes in experimental rats, and thus halt the early steps of the development of diabetic nephropathy. mTOR blockade might be beneficial for the treatment of diabetic nephropathy.

Urinary fractalkine is a marker of acute rejection

Chemokines and their receptors play an important role in the development of allograft rejection through directing mononuclear cell invasion of the graft. To study whether chemokine assays in the urine could prove to be predictive of acute rejection, we measured the urinary excretion of several chemokines, including fractalkine, chemokine monokine induced by interferon-gamma, interferon-gamma-inducible protein 10, macrophage inflammatory protein-3 alpha, granzyme B, and perforin in 215 allograft recipients and in 80 healthy control subjects. The 67 patients with acute rejection had significantly higher levels of all urinary chemokines compared to the healthy controls or patients having chronic allograft nephropathy but with stable renal function. Only changes in urinary fractalkine differentiated patients with acute rejection from those with acute tubular necrosis. The 7 patients who lost their grafts had greater urinary fractalkine, interferon-gamma, and macrophage inflammatory protein-3 alpha concentrations than those patients with reversible acute rejection. The area under the receiver operating characteristic curve for fractalkine was the best indicator among all of the markers differentiating 39 patients diagnosed with steroid-resistant from the 28 patients with steroid-sensitive acute rejection and in predicting graft loss. Our study shows that measuring urinary fractalkine levels is a noninvasive approach for detecting acute rejection where high levels were associated with steroid-resistance and poor outcome.

Mitochondrial DNA haplogroup R predicts survival advantage in severe sepsis in the Han population

Purpose: To determine whether the main mitochondrial DNA (mtDNA) haplogroups of the Han people have an impact on long-term clinical outcome.Methods: We prospectively studied 181 individuals who were sequentially admitted to the intensive care unit. Demographic and clinical data were recorded along with clinical outcome over 180 days. Follow-up was completed for all study participants. We then determined the mtDNA haplogroups of the patients and 570 healthy, age-matched Han people from Zhejiang province, Southeast China, by analyzing sequences of hypervariable mtDNA segments and testing diagnostic polymorphisms in the mtDNA coding region with DNA probes.Result: The frequency of the main subhaplogroups of the Han population in the study cohort did not differ significantly from the control group. mtDNA haplogroup R, one of the three main mtDNA haplogroups of the Han people, was a strong independent predictor for the outcome of severe sepsis, conferring a 4.68-fold (95% CI 1.903–10.844, P = 0.001) increased chance of survival at 180 days compared with those without the haplogroup R.Conclusion: In the Han population, mtDNA haplogroup R was a strong independent predictor for the outcome of severe sepsis, conferring an increased chance of long-term survival compared with individuals without the R haplogroup.

Angiotensin (1 7) prevent heart dysfunction and left ventricular remodeling caused by renal dysfunction in 5/6 nephrectomy mice

The renin–angiotensin system (RAS) plays a critical role in chronic renal failure associated with heart failure. In the past few years, angiotensin (Ang) (1–7) have been reported to counteract the effects of angiotensin II (Ang II) and were even considered as a new therapeutical target in RAS. The purposes of this study were to examine whether the Ang (1–7) improves the heart function and remodeling of the left ventricle (LV) in mice with 5/6 nephrectomy (NC). We used a 5/6 nephrectomy to induce significant renal dysfunction in wildtype mice (WT). Twelve weeks after NC, WT showed high blood pressure, significant left-ventricular dilation and dysfunction, which were accompanied by cardiomyocyte hypertrophy, diffuse interstitial fibrosis and oxidative damage of cardiomyocytes. Exogenous Ang (1–7) injection improved the heart function and remodeling of LV in mice with 5/6 NC accompanied by a reduction in cardiac interstitial fibrosis, inflammatory cytokine expression and oxidative damage levels of cardiomyocytes, decrease in the profibrotic signaling molecule transforming growth factor (TGF)-β and increase in the collagen degradation signaling molecule matrix metalloproteinase (MMP)-2, -9. However, these beneficial effects did not occur in hydralazine-treated mice. These findings suggest that (1) Exogenous Ang (1–7) injection improve the heart function and remodeling of LV in mice with 5/6 NC. (2) These beneficial effects are independent of its anti-blood pressure effect.

A pilot study of GC/MS-based serum metabolic profiling of acute rejection in renal transplantation.

AIMS Acute allograft rejection is one of the important complications after renal transplantation, and it is a deleterious factor for long-term graft survival. Rejection is a complex pathophysiologic process, which has been explained by transcriptome and proteome in RNA transcripts and proteins level respectively. How are serum metabolite levels in response to acute rejection? Can metabolite levels in serum be used to diagnose and explain acute renal allograft rejection? METHODS Gas chromatograph-mass spectrometry (GC-MS) was used to analyze serum metabolome in 22 recipients of acute rejection and 15 stable renal transplant recipients. RESULTS 46 endogenous metabolites included amino acid, fatty acid, carbohydrate and other intermediate metabolites were identified in 37 recipients. Principal component analysis based on these metabolites discriminated acute rejection group from stable recipients. Among these metabolites, the levels of 17 metabolites were significant higher in rejection group than those in stable group. These included amino acid (phenylalanine, serine, glycine, threonine, valine), carbohydrate (galactose oxime, glycose, fructose), carboxylic acid, lipids and other metabolite such as lactate, urea and myo-inositol. The levels of 5 metabolites of alanine, lysine, leucine, aminomalonic acid and tetradecanoic acid were low in rejection group compared to stable group. The prediction accuracy of acute rejection was 77.3% and stable function was 100% by supervised clustering based on these 22 metabolites. CONCLUSIONS This study demonstrated that metabolic profile was changed in response to rejection process and renal function can be reflected by serum metabolite levels. This study showed potential capability to diagnose acute rejection by metabolome analysis.

Acute renal allograft rejection is associated with increased levels of vascular endothelial growth factor in the urine

Aim:  The purpose of this study was to assess whether measurement of urinary vascular endothelial growth factor (VEGF) could be adopted as a new non‐invasive diagnostic tool for acute rejection following renal transplantation.

Dual effects of statins therapy in systemic lupus erythematosus and SLE-related atherosclerosis: The potential role for regulatory T cells

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease associated with accelerated atherosclerosis independent of traditional risk factors. Statins, the 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors, have been widely prescribed for hyperlipidemia, which could slow the atherosclerosis progression, and reduce cardiovascular disease events. Nonetheless, accumulated evidences suggested that statins exert immunomodulatory and anti-inflammatory functions independent of their lipid-lowering effects. By the virtue of pleiotropic immunomodulatory property, statins may be applied for the treatment of both autoimmunity and atherosclerosis in patients with SLE. Interestingly, it has been well documented that regulatory T cells (Tregs) are involved in the pathogenesis of SLE as well as atherosclerosis. Meanwhile, studies have shown that statins could induce augmented number of Tregs with increased functional inhibitory properties. Thus, we hypothesized that the effect of statins ameliorating lupus disease manifestations and lupus-mediated atherogenesis might be mediated, at least partly, via the activation of Tregs. To our knowledge, this is the first hypothesis focused on that Tregs might be involved in the immunomodulatory effect of statins on SLE and SLE-related atherosclerosis.

Non-invasive Detection of Acute Renal Allograft Rejection by Measurement of Vascular Endothelial Growth Factor in Urine

Urinary vascular endothelial growth factor (VEGF) was determined by enzyme-linked immunosorbent assay in 199 renal allograft recipients and 80 healthy controls. Urinary VEGF level did not change significantly during the first 8 weeks after transplantation in 119 patients with stable renal function and there were no abnormal histological findings (No-AR). In 67 patients with acute rejection, urinary VEGF was significantly higher (28.57 ± 6.21 pg/μmol creatinine) than in the No-AR patients (3.05 ± 0.45 pg/μmol creatinine) and healthy controls (2.87 ± 0.35 pg/μmol creatinine). At a cut-off point of 3.26 pg/μmol creatinine, sensitivity and specificity for diagnosis of acute rejection were 86.6 and 71.4%, respectively. The 13 patients with subclinical rejection excreted urinary VEGF (16.14 ± 4.09 pg/μmol creatinine) at a significantly higher level than No-AR patients (3.05 ± 0.45 pg/μmol creatinine). At a cut-off point of 4.69 pg/μmol creatinine, sensitivity and specificity for diagnosis of subclinical rejection were 84.6 and 79.8%, respectively. In conclusion, monitoring VEGF in urine might offer a new non-invasive way to detect acute and subclinical rejection in renal transplant recipients.

The regulatory/cytotoxic infiltrating T cells in early renal surveillance biopsies predicts acute rejection and survival

BACKGROUND To analyze the immune phenotype of T-lymphocyte infiltrations in surveillance renal biopsies with stable renal function early post-transplantation (median time 40 days, range from 18 to 85 days). METHODS One hundred and twenty-five surveillance biopsies with interstitial T-lymphocyte infiltration between non-atrophic tubules in the cortex (14 with subclinical rejection, 32 with borderline change and 79 with only interstitial T-lymphocyte infiltration but no obvious pathological abnormalities according to Banff criteria) were enrolled. All cases were classified into two groups: regulatory phenotype (RP) group, which was dominated by FOXP3-positive T lymphocytes in surveillance biopsies, and cytotoxic phenotype (CP) group, which was dominated by Granzyme B-positive T lymphocytes. RESULTS The RP group includes 83.2% (104/125) cases, none of which developed acute rejection during nearly 5 years of follow-up. The CP group includes 16.8% (21/125) cases, all of which developed biopsy-proven acute rejection or clinical diagnostic acute rejection within 1 year after biopsy. Glomerular filtration rate and cumulative graft survival time were superior in the RP group than in the CP group (P<0.001). CONCLUSION Analyzing the immunophenotype of graft-infiltrating T cells in renal surveillance biopsies during early post-transplantation could predict acute rejection and survival.

Pretreatment with granulocyte colony‐stimulating factor attenuated renal ischaemia and reperfusion injury via activation of PI3/Akt signal pathway

Aim:  Granulocyte colony‐stimulating factor (G‐CSF) has been shown to exert protective effects in various tissues and experimental models of ischaemia‐induced injury. However, the mechanism of renoprotective action in ischaemia/reperfusion (I/R) renal injury of G‐CSF was unknown.