法尼酯衍生物X受体（FXR）在糖尿病肾病中的研究进展

糖尿病肾病（DN）是糖尿病常见的慢性微血管并发症,最初是由高血糖引起的肾脏适应性高滤过率,进而导致肾脏细胞的代偿性增生、炎症以及纤维化。法尼酯X受体（FXR）被证明对糖尿病肾病有负性调节的作用,FXR可以通过不同的方面（血糖、血脂、炎症以及纤维化）对糖尿病肾病进行调控,从而有效的控制糖尿病肾病的发生和发展。本文将对FXR以及FXR调控糖尿病肾病的不同方面予以综述。     

老年2型糖尿病早期肾病患者肠道菌群多样性

目的探讨老年2型糖尿病早期肾病患者肠道菌群的多样性。方法选取2018年1月至2019年10月我院收治的47例2型糖尿病早期肾脏并发症患者(糖尿病肾病组)和53例2型糖尿病无并发症患者(2型糖尿病组)作为研究对象,另将同期在我院行体检的42例健康者作为对照组,采集3组对象粪便标本,提取并扩增粪便样本中细菌的16S rDNA,利用高通量测序技术对16S rDNA进行测序,进行可操作分类单元(OTU)划分,并对比分析各样本的Alpha多样性及菌群门类组成。结果糖尿病肾病组独有的OTU有441个,2型糖尿病组独有的OTU有708个,对照组独有的OTU有559个,3组共有的OTU有1 847个。3组对象肠道菌群Ace、Chao1、Simpson和Shannon等指数相比差异均无统计学意义(均P0.05)。糖尿病肾病组、2型糖尿病组、对照组对象肠道菌群Ace指数和Chao1指数依次升高,糖尿病肾病组和2型糖尿病组患者Simpson指数和Shannon指数均低于对照组(均P0.05)。3组对象肠道菌群主要组成门类为厚壁菌门、变形菌门、放线菌门和拟杆菌门。糖尿病肾病组、2型糖尿病组、对照组对象肠道厚壁菌门与拟杆菌门的比值依次升高。结论老年2型糖尿病早期肾病患者的肠道菌群多样性下降,肠道菌群失调可能与2型糖尿病肾病的发生发展存在一定的关系。     

Hypoglycaemic, antioxidative and nephroprotective effects of taurine in alloxan diabetic rabbits

The therapeutic potential of taurine was investigated under diabetic conditions. Alloxan diabetic rabbits were treated daily for three weeks with 1% taurine in drinking water. The following parameters were measured: 1) serum glucose, urea, creatinine and hydroxyl free radical (HFR) levels; 2) blood glutathione redox state; 3) urine albumin concentration; 4) hepatic and renal HFR levels, GSH/GSSG ratios and the activities of catalase, superoxide dismutase and the enzymes of glutathione metabolism; 5) renal NADPH oxidase activity; 6) the rates of renal and hepatic gluconeogenesis. Histological studies of kidneys were also performed. Taurine administration to diabetic rabbits resulted in 30% decrease in serum glucose level and the normalisation of diabetes-elevated rate of renal gluconeogenesis. It also decreased serum urea and creatinine concentrations, attenuated diabetes-evoked decline in GSH/GSSG ratio and abolished hydroxyl free radicals accumulation in serum, liver and kidney cortex. Animals treated with taurine exhibited elevated activities of hepatic gamma-glutamylcysteine syntetase and renal glutathione reductase and catalase. Moreover, taurine treatment evoked the normalisation of diabetes-stimulated activity of renal NADPH oxidase and attenuated both albuminuria and glomerulopathy characteristic of diabetes. In view of these data, it is concluded that: 1) diminished rate of renal gluconeogenesis seems to contribute to hypoglycaemic effect of taurine; 2) taurine-induced increase in the activities of catalase and the enzymes of glutathione metabolism is of importance for antioxidative action of this amino acid and 3) taurine nephroprotective properties might result from diminished renal NADPH oxidase activity. Thus, taurine seems to be beneficial for the therapy of both diabetes and diabetic nephropathy.     

Ochratoxin A and fumonisins (B1 and B2) in maize from Balkan nephropathy endemic and non endemic areas of Croatia

The occurrence of ochratoxin A, fumonisin B1 and B2 has been investigated in maize samples collected in 1996 (105 samples) and 1997 (104 samples) in 14 counties of Croatia, including Brodsko-Posavska county, the main area of Balkan endemic nephropathy in Croatia. Ochratoxin A and fumonisins co-occurred in 21% of the examined samples. In particular, ochratoxin A (OTA) was found in 10 samples (10%) of the 1996 and 36 samples (35%) of the 1997 crops with mean concentrations of positive samples of 37.9 ng/g and 57.1 ng/g, and highest concentrations at 223.6 ng/g and 613.7 ng/g, respectively. Similar incidence of OTA contamination was observed in 1996 samples from both endemic and non endemic areas of Balkan nephropathy, whereas a significant difference (P<0.01) was found between the two areas in 1997, with 50% and 20% incidence of contamination in the endemic and non endemic area, respectively, and relevant OTA mean concentration of positive samples of 73.4 ng/g and 20.2 ng/g. High incidence of infection byPenicillium spp. (potential OTA producers) was found in all tested samples, with mean values of 88% and 93% in samples of 1996 and 1997, respectively. With respect to fumonisin B1 (FB1) and B2 (FB2) all but one of the 1996 samples were contaminated, with highest and mean concentrations of positive samples (FB1+FB2) at 11661 ng/g and 645 ng/g, respectively. Similar incidence of positive samples (93%), but lower contamination levels (mean 134 ng/g, maximum 2524 ng/g) were found in 1997 samples. The results of fumonisin analysis were in agreement with the mycological analysis showing higher incidence of Fusarium infection in samples of 1996 with respect to those of 1997. These data provide additional information on the occurrence of ochratoxin A in Balkan endemic nephropathy areas and, for the first time, its co-occurrence with other nephrotoxic compounds, such as fumonisins, that may contribute to the disease development. However the finding of these mycotoxins in the non-endemic areas, also at high levels, do not allow to draw a conclusion about their role in the etiology of the disease.     

Different Sodium-Glucose Cotransporter-2 Inhibitors: Can They Prevent Death?

ObjectiveSodium-glucose cotransporter-2 inhibitors (SGLT2is) in cardiovascular outcome trials (CVOTs) demonstrate cardiovascular (CV) safety and benefits. Some dedicated randomized controlled trials (RCTs) demonstrate benefit in terms of renal outcomes and hospitalization due to heart failure (HF). RCTs report differences in the secondary outcomes with respect to mortality (CV and/or all-cause). We undertook a meta-analysis of all SGLT2is for which in addition to CVOT, HF outcome/renal outcome studies are available to establish whether individual SGLT2is were able to prevent death.MethodsWe included available event-driven randomized, placebo-controlled CVOTs and dedicated RCTs of SGLT2is exploring renal outcomes and HF. We included 3 trials of empagliflozin, 3 of dapagliflozin, 2 of canagliflozin, and 2 of sotagliflozin. The efficacy outcomes included all-cause mortality and CV mortality. Hazard ratios (HRs) with 95% CIs were pooled for individual molecules.ResultsThe HR for all-cause mortality including all trials was 0.86 (0.80-0.93). The HRs for all-cause mortality in empagliflozin (N = 16 738), dapagliflozin (N = 26 208), canagliflozin (N = 14 543), and sotagliflozin (N = 11 806) were 0.86 (0.69-1.08), 0.83 (0.72-0.97), 0.86 (0.75-0.97), and 0.95 (0.81-1.11), respectively. The HR for CV mortality including all trials was 0.85 (0.78-0.92). The HRs for CV mortality in empagliflozin, dapagliflozin, sotagliflozin, and canagliflozin were 0.81 (0.63-1.03), 0.88 (0.78-1.00), 0.89 (0.74-1.07), and 0.84 (0.72-0.98), respectively.ConclusionSGLT2is as a class reduce both all-cause mortality and CV mortality. Canagliflozin possibly reduces both all-cause mortality and CV mortality, whereas dapagliflozin may reduce all-cause mortality but not CV mortality. Empagliflozin and sotagliflozin may reduce neither.     

In silico identification of potential drug compound against Peroxisome proliferator-activated receptor-gamma by virtual screening and toxicity studies for the treatment of Diabetic Nephropathy

Diabetic Nephropathy is a serious complication of diabetes mellitus. Current therapeutic strategies of Diabetic Nephropathy are based on control of modifiable risks like hypertension, glucose levels, and dyslipidemia. Peroxisome proliferator activated receptor-gamma (PPAR-γ) is implicated in several metabolic syndromes including Diabetic Nephropathy, besides obesity, insulin insensitivity, dislipidemia, inflammation, and hypertension. In the present study, virtual screening of 617 compounds from two different public databases was done against PPAR-γ with an objective to find a possible lead compound. Two softwares, PyRx and iGEMDOCK, were used to achieve the docking accuracy in order to avoid loss of candidate compounds. Rosiglitazone (used to treat Diabetic Nephropathy) was taken as the standard compound. A total of 30 compounds with good binding affinity with PPAR-γ were selected for further filtering, on the basis of absorption, distribution, metabolism, excretion, and toxicity (ADMET). The interaction profiling of these 30 compounds, showed a minimum of one and maximum of three interactions with reference to rosiglitazone (SER-289, HIS-449, HIS-323, TYR-473). The fulfilling of ADMET analysis criteria of 30 compounds led to the selection of four compounds (ZINC ID 00181552, 00276456, 00298314, 00448009). Molecular dynamics simulation of these lead compounds in complex with PPAR-γ revealed that three of the four compounds formed a stable complex in the ligand-binding pocket of PPAR-γ during 20-ns simulation. Hence, these three (ZINC ID 00181552, 00276456, 00298314) of the four compounds are potential candidates for experimental validation of biological activity against PPAR-γ in future drug discovery studies.     

Purinergic signalling and diabetes

The pancreas is an organ with a central role in nutrient breakdown, nutrient sensing and release of hormones regulating whole body nutrient homeostasis. In diabetes mellitus, the balance is broken—cells can be starving in the midst of plenty. There are indications that the incidence of diabetes type 1 and 2, and possibly pancreatogenic diabetes, is rising globally. Events leading to insulin secretion and action are complex, but there is emerging evidence that intracellular nucleotides and nucleotides are not only important as intracellular energy molecules but also as extracellular signalling molecules in purinergic signalling cascades. This signalling takes place at the level of the pancreas, where the close apposition of various cells—endocrine, exocrine, stromal and immune cells—contributes to the integrated function. Following an introduction to diabetes, the pancreas and purinergic signalling, we will focus on the role of purinergic signalling and its changes associated with diabetes in the pancreas and selected tissues/organ systems affected by hyperglycaemia and other stress molecules of diabetes. Since this is the first review of this kind, a comprehensive historical angle is taken, and common and divergent roles of receptors for nucleotides and nucleosides in different organ systems will be given. This integrated picture will aid our understanding of the challenges of the potential and currently used drugs targeted to specific organ/cells or disorders associated with diabetes.     

The role of extracellular vesicles in podocyte autophagy in kidney disease

Podocytes are the key cells involved in protein filtration in the glomerulus. Once proteins appear in the urine when podocytes fail, patients will end with renal failure due to the progression of glomerular damage if no proper treatment is applied. The injury and loss of podocytes can be attributed to diverse factors, such as genetic, immunologic, toxic, or metabolic disorders. Recently, autophagy has emerged as a key mechanism to eliminate the unwanted cytoplasmic materials and to prolong the lifespan of podocytes by alleviating cell damage and stress. Typically, the fundamental function of extracellular vesicles (EVs) is to mediate the intercellular communication. Recent studies have suggested that, EVs, especially exosomes, play a certain role in information transfer by communicating proteins, mRNAs, and microRNAs with recipient cells. Under physiological and pathological conditions, EVs assist in the bioinformation interchange between kidneys and other organs. It is suggested that EVs are related to the pathogenesis of acute kidney injury and chronic kidney disease, including glomerular disease, diabetic nephropathy, renal fibrosis and end-stage renal disease. However, the role of EVs in podocyte autophagy remains unclear so far. Here, this study integrated the existing information about the relevancy, diagnostic value and therapeutic potential of EVs in a variety of podocytes-related diseases. The accumulating evidence highlighted that autophagy played a critical role in the homeostasis of podocytes in glomerular disease.