系膜细胞丝裂原活化蛋白激酶在糖尿病肾病发病中的作用

蛋白激酶Ｃ(ＰＫＣ)在糖尿病肾病发病中的作用已受到广泛重视和研究〔1〕。本研究采用免疫组化和激光共聚焦显微镜技术 ,观察丝裂原活化蛋白激酶 (ＭＡＰＫ)在糖尿病大鼠肾脏中的表达和作用 ,并探讨其激活机制。一、材料和方法1.试剂和仪器 :链脲佐菌素 (ＳＴＺ)、血管紧张素Ⅱ (ＡｎｇⅡ )购自Ｓｉｇｍａ公司 ,ｐ4 2ＭＡＰＫ抗体购自ＳａｎｔａＣｒｕｚ公司 ,激光共聚焦显微镜购自美国Ｂｉｏ Ｒａｄ公司 (10 2 4型 )。2 .糖尿病大鼠模型的建立和ＭＡＰＫ在肾脏的表达 :将Ｗｉｓｔａｒ大鼠分成糖尿病组和对照组 ,ＳＴＺ复制糖尿病模型 ,喂养…     

足细胞自噬与糖尿病肾病

自噬是机体主要防御机制之一,在代谢器官和疾病的发展中发挥重要的作用.高糖状态可抑制足细胞自噬活性,导致糖尿病肾病的发生、发展.研究表明,哺乳动物雷帕霉素靶蛋白(mTOR)、AMP活化蛋白激酶(AMPK)、沉默信息调节因子1(Sirt1)、内质网应激(ERS)和晚期糖基化终末产物(AGE)等营养信号通路对自噬有重要的调控作用,可能参与糖尿病肾病的发生、发展,有望成为糖尿病肾病防治新的靶点.     

糖尿病肾病足细胞损伤的表观遗传调控

表观遗传修饰是糖尿病肾病的重要机制之一,足细胞损伤是疾病进展的核心事件。不同表观遗传修饰方式可通过单独作用或交叉对话,改变足细胞结构和功能、促进足细胞凋亡及上皮间充质转化、影响足细胞自噬,以及参与足细胞内质网应激和线粒体功能障碍等过程,参与足细胞损伤。表观遗传是可逆的,通过治疗干预改变表观遗传修饰可能是防治糖尿病肾病的一个重要方向。     

艾塞那肽对糖尿病肾病小鼠足细胞的保护作用

目的:探讨艾塞那肽对糖尿病肾病小鼠足细胞的作用。方法:通过给予C57BL/6J小鼠高脂饮食并注射链脲佐菌素建立糖尿病肾病模型,按随机数字表法将其分为糖尿病肾病对照组(DN组, n＝8)、艾塞那肽干预组(DN＋Ex组, n＝8)。同时将普通饲料喂养的C57BL/6J小鼠作为正常对照组(NC组, ...     

The glomerular podocyte as a target of growth hormone action: implications for the pathogenesis of diabetic nephropathy

Involvement of the growth hormone (GH) / insulin-like growth factor 1 (IGF-I) axis in the pathogenesis of diabetic nephropathy (DN) is strongly suggested by studies investigating the impact of GH excess and deficiency on renal structure and function. GH excess in both the human (acromegaly) and in transgenic animal models is characterized by significant structural and functional changes in the kidney. In the human a direct relationship has been noted between the activity of the GH/IGF-1 axis and renal hypertrophy, microalbuminuria, and glomerulosclerosis. Conversely, states of GH deficiency or deficiency or inhibition of GH receptor (GHR) activity confer a protective effect against DN. The glomerular podocyte plays a central and critical role in the structural and functional integrity of the glomerular filtration barrier and maintenance of normal renal function. Recent studies have revealed that the glomerular podocyte is a target of GH action and that GH's actions on the podocyte could be detrimental to the structure and function of the podocyte. These results provide a novel mechanism for GH's role in the pathogenesis of DN and offer the possibility of targeting the GH/IGF-1 axis for the prevention and treatment of DN.     

The pathogenesis of diabetic nephropathy

Between 20% and 40% of patients with diabetes ultimately develop diabetic nephropathy, which in the US is the most common cause of end-stage renal disease requiring dialysis. Diabetic nephropathy has several distinct phases of development and multiple mechanisms contribute to the development of the disease and its outcomes. This Review provides a summary of the latest published data dealing with these mechanisms; it focuses not only on candidate genes associated with susceptibility to diabetic nephropathy but also on alterations in various cytokines and their interaction with products of advanced glycation and oxidant stress. Additionally, the interactions between fibrotic and hemodynamic cytokines, such as transforming growth factor beta1 and angiotensin II, respectively, are discussed in the context of new information concerning nephropathy development. We touch on the expanding clinical data regarding markers of nephropathy, such as microalbuminuria, and put them into context; microalbuminuria reflects cardiovascular and not renal risk. If albuminuria levels continue to increase over time then nephropathy is present. Lastly, we look at advances being made to enable identification of genetically predisposed individuals.     

Microinflammation in the pathogenesis of diabetic nephropathy

Diabetic nephropathy is the leading cause of end‐stage renal failure in developed countries. Furthermore, diabetic nephropathy is related to the risk of cardiovascular diseases and an increase in mortality of diabetic patients. Several factors are involved in the development of nephropathy, including glomerular hyperfiltration, oxidative stress, accumulation of advanced glycation end‐products, activation of protein kinase C, acceleration of the polyol pathway and over‐expression of transforming growth factor‐β. Recently, accumulated data have emphasized the critical roles of chronic low‐grade inflammation, ‘microinflammation’, in the pathogenesis of diabetic nephropathy, suggesting that microinflammation is a common mechanism in the development of diabetic vascular complications. Expression of cell adhesion molecules, chemokines and pro‐inflammatory cytokines are increased in the renal tissues of diabetic patients and animals. Deficiency of pro‐inflammatory molecules results in amelioration of renal injuries after induction of diabetes in mice. Plasma and urinary levels of cytokines, chemokines and cell adhesion molecules, are elevated and correlated with albuminuria. Several kinds of drugs that have anti‐inflammatory actions as their pleiotropic effects showed renoprotective effects on diabetic animals. Modulation of the inflammatory process prevents renal insufficiency in diabetic animal models, suggesting that microinflammation is one of the promising therapeutic targets for diabetic nephropathy, as well as for cardiovascular diseases.     

糖尿病肾病患者尿足细胞脱落及其与尿蛋白的关系

目的 通过观察糖尿病肾病(DN)患者尿中足细胞及肾活检标本足细胞脱落情况,探讨尿中足细胞脱落与尿蛋白、空腹血糖、肌酐的关系.方法 选取2005年1月至2006年12月间天津医科大学总医院收治的DN患者50例,微小病变(MCD)患者25例及正常人对照组10例,按照慢性肾脏病(CKD)分期将DN患者分为5组,其中CKD I期15例,CKD Ⅱ期10例,CKD Ⅲ期8例,CKD IV期9例,CKD V期8例;另按尿蛋白量将DN患者分为3组,其中少量蛋白尿组(<1.0 g/d)13例,中量蛋白尿组(1-3.5 g/d)20例,大量蛋白尿组(>3.5 g/d)17例,采用间接免疫荧光法检测尿足细胞数目及肾小球足细胞特异性蛋白(podocalyxin,PCX)表达;分别统计各组中尿足细胞数目;同时检测各组患者24h尿蛋白、肌酐、空腹血糖,多组计量指标比较采用单因素方差分析,双变量分析采用Pearson相关分析.结果 DN组尿中足细胞的阳性率为88%(44/50);微小病变(MCD)组及正常对照组中阳性率为0;DN组患者的肾活检标本中,肾小球足细胞PCX表达缺失,MCD组肾活检标本足细胞PCX呈完整连续性表达.少量蛋白尿组尿足细胞数目(1.5±1.0)个/ml,中等量蛋白尿组(2.2±0.7)个/ml及大量蛋白尿组(3.5±1.3)个/ml,除少量蛋白尿与中量蛋白尿组差别不具有统计学意义外,其他组间差别均具有统计学意义(P<0.05).DN患者尿足细胞数目与蛋白尿(r=0.785,P<0.05)、I-Ⅲ期患者同期SCr呈正相关(r=0.466,P<0.05);而与FBG无相关性(P>0.05).结论 DN进展过程中存在足细胞损伤.DN足细胞脱落与尿蛋白、CKD I至Ⅲ期同期SCr呈正相关,与Ⅳ至V期SCr、FBG无关.     

Mindin:糖尿病肾病足细胞损伤的新型标记物

Mindin(也称spondin-2)是一个高度同源的细胞外基质蛋白,既往研究发现,mindin可作为病原微生物模式识别分子和整合素配体参与非特异性和特异性免疫反应,并有促进神经元的黏附和生长的功能.近年研究发现,mindin可由损伤的足细胞合成,其参与糖尿病肾病的发生、发展,并与糖尿病足细胞损伤密切相关.与健康人相比,2型糖尿病患者的尿液mindin表达增加,并能反映糖尿病肾病严重程度.因此,mindin有望成为糖尿病肾病足细胞损伤新标记物.     

糖尿病肾病的发病机制及治疗进展

糖尿病肾病是糖尿病的主要微血管并发症之一,其发病机制仍未完全阐明,可能与糖代谢紊乱、炎症反应、遗传、血流动力学异常、氧化应激等多种因素有关,在治疗上主要通过饮食、血糖、血压、血脂的控制等方法来加以干预,以延缓病情进展和提高患者生活质量。该文就近年来关于糖尿病肾病的发病机制和治疗进展作一综述。     

Visfatin与胰岛素抵抗及糖尿病肾病的发病机制

Visfatin是哺乳动物合成烟酰胺腺嘌呤二核苷酸(NAD)的限速酶,同时具有类炎性反应因子样作用,可通过cAMP反应元件结合蛋白/蛋白激酶A途径调控肝脏糖异生及葡萄糖代谢,通过NAD、沉默信息调节因子1参与调节胰岛素敏感性及胰岛β细胞功能.此外,visfatin还可调节肾细胞的胰岛素信号转导及葡萄糖代谢,与炎性因子、肾素-血管紧张素系统相互作用,参与糖尿病肾病的发生、发展,为糖尿病及糖尿病肾病的治疗提供新思路.     

Carbonyl stress in the pathogenesis of diabetic nephropathy.

Diabetic nephropathy is a major chronic complication of diabetes mellitus and an important cause of increased morbidity and mortality in diabetic patients. Although several lines of evidence have suggested that poor glycemic control undoubtedly plays a significant role, the metabolic events responsible for its development are not understood well. Possible mediators of untowards effects of hyperglycemia include the advanced glycation end products (AGEs). AGEs, carboxymethyllysine and pentosidine, whose formation is closely linked to oxidation, accumulate in the characteristic diabetic glomerular lesions, such as the expanded mesangial matrix and nodular lesions, in co-localization with other oxidation-specific protein adducts, such as malondialdehyde-lysine, 4-hydroxynonenal-protein adduct, and acrolein-protein adduct. These five biomarkers are formed under oxidative stress by carbonyl amine chemistry between protein amino group and carbonyl compounds derived from carbohydrates, lipids, and amino acids. This article focuses on new aspects of the pathology of diabetic nephropathy, implicating an increased oxidative stress and carbonyl modification of proteins by autoxidation products of carbohydrates, lipids, and amino acids in diabetic glomerular tissue damage ("carbonyl stress").     

Association analysis of podocyte slit diaphragm genes as candidates for diabetic nephropathy

Aims/hypothesis The slit diaphragm is an adhesion and signalling protein complex linking the interdigitating podocyte foot processes in the kidney glomerulus, and mutations in slit diaphragm-associated genes result in severe proteinuria. Here we report a genetic association analysis of four slit diaphragm genes, LRRC7, KIRREL, NPHS2 and ACTN4, in a Finnish diabetic nephropathy cohort. Materials and methods A total of 40 single nucleotide polymorphisms (SNPs) were genotyped in 1103 patients with type 1 diabetes. The patients were classified according to their renal status, and the genotype data were analysed in a cross-sectional case–control setting. To confirm positive associations, four SNPs were genotyped in 1,025 additional patients with type 1 diabetes. Results No associations with diabetic nephropathy were observed for any of the analysed SNPs. The SNPs were not associated with the time from the onset of diabetes to the diagnosis of nephropathy or with glomerular filtration rate or AER as quantitative variables. In a sex-specific sub-analysis, the variants rs979972 and rs749701 in the first intron of ACTN4 were nominally associated with diabetic nephropathy in females, with odds ratios of 1.81 (95% CI 1.18–2.79, p = 0.007) and 1.93 (95% CI 1.26–2.96, p = 0.003) respectively. Conclusions/interpretation Our study has not found any evidence that common variants in LRRC7, KIRREL, NPHS2 and ACTN4 contribute to susceptibility to diabetic nephropathy in Finnish patients with type 1 diabetes. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users.     

雷公藤多甙联合厄贝沙坦对糖尿病肾病大鼠足细胞nephrin和podocin表达的影响

目的 观察雷公藤多甙联合厄贝沙坦对糖尿病肾病大鼠足细胞nephrin和podocinmRNA和蛋白表达的影响.方法 将体重200 ～ 260 g的50只SD大鼠按随机数字表法分为正常对照组和4个模型组（n=10）,后者分别应用链脲佐菌素造模成功后分为糖尿病肾病组（DN组）、厄贝沙坦组、雷公藤多甙组和雷公藤多甙联合厄贝沙坦组.给予相应干预8周后,检测血尿指标,HE染色观察肾组织病理变化,逆转录-多聚酶链反应（RT-PCR）法检测各组大鼠肾皮质中nephrin和podocinmRNA和蛋白表达.结果 （1）与DN组大鼠比较,雷公藤多甙联合厄贝沙坦组大鼠肾皮质nephrin mRNA （0.507±0.024比0.276 ±0.015,P ＜0.01）和podocin mRNA （0.533±0.024比0.463±0.022,P＜0.01）表达上调.（2）与DN组大鼠比较,雷公藤多甙联合厄贝沙坦组大鼠肾皮质nephrin蛋白（0.738±0.029比0.199±0.012,P＜0.01）和podocin蛋白（0.811 ±0.032比0.227±0.014,P＜0.01）表达上调.（3） HE染色和Masson染色显示,糖尿病组大鼠肾脏肾小球体积增大,系膜基质弥漫增多,系膜细胞明显增多,基底膜弥漫增厚,间质可见灶性淋巴细胞及单核细胞浸润,厄贝沙坦组和雷公藤多甙组病变较糖尿病组减轻,雷公藤多甙联合厄贝沙坦组大鼠肾脏组织病变较厄贝沙坦组和雷公藤多甙组进一步减轻.结论 雷公藤多甙联合厄贝沙坦对糖尿病大鼠的肾脏足细胞具有保护作用,这种保护作用可能是通过上调足细胞nephrin和podocin mRNA和蛋白表达有关.