糖尿病肾病肾组织胰淀素沉积及其致病意义

目的观察胰淀素(amylin)在糖尿病肾病(DN)患者肾组织的沉积和分布特征,探讨肾脏Amylin沉积的致病意义及其影响因素。方法149例经肾活检证实的2型DN患者,免疫组化方法检测肾组织Amylin的沉积,同时行肾组织ApoE检测及电镜观察。竞争性ELISA方法检测血浆Amylin水平,结合患者肾脏病理和临床相关指标进行分析。选择同期经肾活检确诊的肾淀粉样变性、肥胖相关性肾病、轻链沉积病和原发性肾小球肾炎(系膜增生性病变)患者作为相关疾病对照组。结果72例DN患者(48.3%)肾组织Amylin染色阳性,Amylin主要沉积在肾小球系膜基质增多而扩张的系膜区、K-W结节内、增厚的球囊壁和病变的血管壁。肾组织电镜可见无分支、长直线形丝状结构,随意分布于肾小球系膜区、内皮下或基膜内,直径(10.30±1.77)nm。DN患者肾组织Amylin沉积者其肾小球系膜增生,结节病变及肾小球硬化的发生率较无Amylin沉积患者明显增高而小管间质病变程度亦较无Amylin沉积患者重(P<0.05)。肾脏Amylin沉积DN患者24h尿蛋白定量、高血压、肾小管功能受损以及肾功能损伤的程度和贫血均较无Amylin肾组织沉积组更加严重(P<0.05)。DN患者血浆Amylin水平均显著增高(P<0.01),但Amylin肾组织染色阳性和阴性组二者之间并无明显差异(P>0.05)。结论DN患者血浆Amylin水平较正常人明显升高,肾脏可发生Amylin沉积。肾组织Amylin沉积不仅可加重肾组织损伤,而且还与疾病临床表现的严重程度有一定的联系。Amylin在肾脏的沉积参与了DN组织损伤的发生和发展。     

中药在慢性肾小球肾炎治疗中的应用进展

慢性肾小球肾炎（CGN）是一种肾脏常见病，主要包括系膜增生性肾炎、膜性肾病、局灶性阶段性肾小球硬化、系膜毛细血管性肾小球肾炎、增生硬化性肾小球肾炎五种。CGN长期反复发作使肾小管和肾间质出现继发病变，肾皮质变薄、肾脏体积逐渐变小。现代研究表明，某些中药及复方制剂具有抑制系膜细胞增生、减轻炎症反应、抑制过氧化反应、减少免疫复合物沉积等作用。现将中药在慢性肾小球肾炎治疗中的应用进展综述如下。     

肾小球疾病中肾小管间质纤维化的研究

目的 研究肾小球疾病中肾小管间质纤维化的发生机制。方法 通过对44例病因、病理类型和肾功能损伤程度不同的原发性和继发性肾小球疾病的临床和病理分析研究(包括硬化性肾小球肾炎15例、结节性硬化性糖尿病肾病10例，膜性肾病19例)肾小球、肾小管和肾间质的损伤，并进行TGFβ1、α-SMA、I、Ⅲ型胶原蛋白表达的回顾性分析，探讨它们与肾小管间质损伤之间的关系。结果 肾小球的损伤与肾小管间质纤维化密切相关;TGFβ1的表达位于损伤的肾小管上皮细胞，Ⅰ、Ⅲ型胶原和肌纤维母细胞(α—SMA阳性细胞)主要位于增生的肾间质，其中，Ⅰ、Ⅲ型胶原还见于部分肾小管上皮细胞。它们的表达均与肾小管间质损伤程度相关。肾小管TGFβ1的表达还与肾间质肌纤维母细胞及Ⅲ型胶原的表达相关。肾间质肌纤维母细胞的表达又与肾间质Ⅰ、Ⅲ型胶原表达相关。结论 损伤的肾小管是肾小管间质纤维化的中心环节。受缺血缺氧、尿蛋白和尿糖损伤的肾小管上皮细胞通过自分泌和旁分泌的途径，产生多种细胞因子(TGFβ1等)和表型转化(产生Ⅰ、Ⅲ型胶原等)，在人类肾小球疾病进行性发展至肾纤维化的过程中起重要作用。     

肾脏纤维化的发生机制及治疗新观点

肾脏纤维化，以肾小球硬化和肾小管间质纤维化为特征，是多种慢性肾脏疾病最终结局。本质上，肾纤维化是以细胞外基质的过度积聚和沉积为特征的过程。产生基质的细胞活化是肾纤维化形成的关键。生理情况下，成纤维细胞（fibroblasts）产生适量的胶原基质充填肾单位、血管和肾被膜之间的空隙。随年龄增长肾脏体积逐渐增大，成纤维细胞主要起肾间质重塑作用。当损伤及炎症因素持续存在时，成纤维细胞增殖并产生过量的细胞外基质。新合成的成纤维胶原成分在肾组织沉积。此外，肾小球系膜细胞和肾小管上皮细胞是主要的产生细胞外基质的细胞。肾纤维化早期，     

糖尿病肾病大鼠肾脏纤维化逆转可能性的研究

目的 动态观察α-平滑肌肌动蛋白(α-SMA)和E-钙黏素(E-cadherin)在糖尿病(DM)大鼠肾组织中的表达,探讨糖尿病肾病(DN)大鼠肾脏纤维化逆转的可能性.方法 选择SD大鼠随机分为正常对照组、DM组和胰岛素治疗组,链脲佐菌素(STZ)诱发大鼠DM.正常对照组和DM组按病程分为2、4、8、12、16、20和24 w组,胰岛素治疗组从第13周起用胰岛素控制血糖至正常水平,分为16、20和24 w组.检测各组血糖、24 h尿蛋白、血肌酐(Scr)和肾脏指数(RI);PAS染色光镜观察肾脏病理改变;免疫组化检测肾皮质α-SMA和纤连蛋白(FN)的表达;Western印迹检测肾皮质α-SMA和E-cadherin蛋白表达量;RT-PCR检测肾皮质α-SMA和FN mRNA水平.结果 DM组大鼠血糖、24 h尿蛋白、Scr、RI均较正常对照组明显升高(P＜0.05,P＜0.01),胰岛素治疗组上述指标均较DM组显著降低(P＜0.05,P＜0.01).正常大鼠α-SMA只在血管壁表达,DM组2 w开始有少量间质细胞胞浆内有阳性染色,随病程进展间质细胞阳性染色增多;8 w时肾小球系膜细胞胞浆内见阳性表达;从16 w开始在DM大鼠肾小管上皮细胞可见α-SMA蛋白阳性表达,胰岛素治疗组未见表达;DM组肾皮质α-SMA和FN蛋白与mRNA表达水平较正常对照组显著增多(P＜0.01),胰岛素治疗组则显著低于DM组(P＜0.01);DM组E-cadherin蛋白的表达水平较正常对照组显著降低(P＜0.01),而胰岛素治疗组显著高于DM组(P＜0.01).结论 控制血糖可使DN大鼠肾脏一定程度的纤维化逆转,其机制可能与肾脏固有细胞表型转变被抑制或反转有关.     

TGF-β1与糖尿病肾病

糖尿病肾病（DN）的基本病理改变首先是肾脏的肥大,继而出现肾小管、肾小球毛细血管基底膜增厚,小球系膜细胞与小管间质细胞外基质（ECM）沉积,最后出现典型的肾小球硬化性病变。近年来,转化生长因子β1（TGF-β1）在患者肾脏肥大、肾小球ECM沉积中的作用备受关注,本文就其与DN的关系综述如下。     

肾小球疾病患者肾间质泡沫细胞的分布及其临床意义

目的：观察肾小球疾病患者肾间质泡沫细胞的分布特点,分析其与临床表现及肾组织病理改变之间的联系.方法：选取经临床病理明确诊断的Alport综合征（AS）125例,特发性膜性肾病（IMN）192例,IgA肾病（IgAN）388例,局灶节段性肾小球硬化（FSGS）137例.观察肾组织泡沫细胞的分布,并对肾间质有无泡沫细胞患者的临床和病理进行比较.结果：（1）AS、IMN、IgAN、FSGS四种疾病肾组织中均存在肾间质泡沫细胞,发生率分别为64.8%、21.4%、12.4%、36.5%,其中以AS中最为多见.（2）肾间质泡沫细胞组肾小球节段硬化的发生率及硬化比例均显著高于无泡沫细胞的对照组,AS、IgAN患者泡沫细胞组间质纤维化程度重于对照组.（3）AS、IgAN患者肾间质泡沫细胞组尿蛋白、血脂水平显著高于对照组（P＜0.01）.FSGS患者肾间质泡沫细胞组三酰甘油水平显著高于对照组,但两组间尿蛋白水平未见差异.结论：肾间质泡沫细胞在AS、IMN、IgAN、FSGS患者中均可以发现,但以AS患者最多见.肾间质泡沫细胞的形成与尿蛋白、血脂的水平有关.肾间质泡沫细胞的存在可能与肾组织慢性化病变形成有关.     

CD40/CD40L在肾小管上皮细胞转分化中的作用及其可能机制

目的 探讨CD40/CD40L在肾小管上皮细胞转分化中的作用及其可能机制.方法 将74例IgA肾病患者肾穿活检组织分为轻度系膜增生组27例、局灶增生组28例和增生硬化组19例,采用免疫组化及Masson方法观察各组肾小管间质内CD40、CD40L、TGF-β、α-SMA、Vimentin和胶原纤维的表达.结果 IgA肾病组织中小管上皮细胞高表达CD40和CD40L,肾小管间质中TGF-β、α-SMA、Vimentin及胶原纤维表达随分级变化而变化,三组间以上指标比较有统计学差异（P＜0.05或＜0.01）.结论 IgA肾病中,CD40和CD40L可能通过TGF-β启动并调节肾小管上皮细胞转分化,参与肾小管间质纤维化.     

基质金属蛋白酶-9和金属蛋白酶组织抑制物-1在IgA肾病肾组织中的表达

目的 探讨基质金属蛋白酶－9（MMP－9）／金属蛋白酶组织抑制物－1（TIMP－1）系统在IgA肾病肾组织中的表达及其对IgA肾病的进展的影响。方法 采用免疫组织化学和原位杂交技术,分别在蛋白质和基因水平检测38例IgA肾病患者肾组织中的MMP－9和TIMP－1的变化。结果 MMP－9在正常肾脏肾小球的脏层上皮细胞和内皮细胞有少量表达,在肾小管上皮细胞和间质血管壁也有少量表达;在IgA肾病中,MMP－9在系膜增殖性肾小球和间质血管壁的表达均明显增多（P＜0．001）,而在硬化肾小球内的表达则明显减少,肾小管细胞的MMP－9表达无明显变化。TIMP－1在正常肾组织中不能检出,在IgA肾病患者具有系膜增殖性病变的肾小球中有微量表达,在增殖在很重但尚未完全硬化的肾小球内表达增多,在肾小管间质表达最为明显（P＜0．001）,其主要见于肾小管细胞、间质细胞和血管内皮细胞。肾组织中的TIMP－1表达与血清肌酐水平呈显著相关（P＜0．05）,与肾小管间质的纤维化和炎细胞浸润程度亦明显相关（P值均＜0．01）。肾小球中的MMP－9表达与尿蛋白无明显相关性,但与血清肌酐水平呈显著负相关（P＜0．05）。结论 MMP－9和TIMP－1的异常表达可能是影响IgA肾病进展的因素之一。     

补体膜攻击复合物和CD59在不同免疫病理类型IgA肾病发病机理中的作用

为进一步阐明导致不同免疫病理类型ＩｇＡ肾病（ＩｇＡＮ）患者预后不同的机理，应用ＰＡＰ四层法对２８例肾小球单纯ＩｇＡ沉积（单纯ＩｇＡ组）及３２例ＩｇＧ、ＩｇＡ、ＩｇＭ共同沉积（ＧＡＭ组）ＩｇＡＮ患者肾组织膜攻击复合物（ＭＡＣ）和ＣＤ５９的分布情况，结合其肾小球内沉积的补体成分以及病理改变和临床特点进行了分析，结果表明：单纯ＩｇＡ组临床表现、病理改变轻，ＧＡＭ组临床表现、病理改变重。ＧＡＭ组肾组织经典途径补体成分Ｃｌｑ、Ｃ４沉积（均为Ｐ＜０．０１），肾小球系膜区及毛细血管袢ＭＡＣ沉积（分别为Ｐ＜０．０５、Ｐ＜０．０１），肾小球硬化＞２５％（Ｐ＜０．０５）和中重度小管间质病变的发生率（Ｐ＜０．０５），均较单纯ＩｇＡ组明显增多，且ＧＡＭ组皮质区域间质面积较单纯ＩｇＡ组明显增宽（Ｐ＜０．０１）。尽管ＣＤ５９在两组中分布无统计学差异，但若按肾小球ＣＤ５９分布强度将患者分为Ａ组（＋）和Ｂ组（２＋），结果发现ＣＤ５９Ａ组肾小球硬化＞２５％（Ｐ＜０．０５），中重度小管间质病变的发生率明显增多（Ｐ＜０．０１），皮质区域间质面积明显增宽（Ｐ＜０．０１）。在硬化的肾小球内ＭＡＣ分布多而ＣＤ５９分布少     

格列喹酮对糖基化终产物诱导的人肾系膜细胞RANTES表达的影响

目的探讨格列喹酮对糖基化终产物（AGEs）诱导的人肾系膜细胞（HRMC）正常T细胞表达分泌的调节活化蛋白（RANTES）表达的影响。方法运用糖基化修饰的牛血清白蛋白（AGE-BSA）和格列喹酮干预体外培养的HRMC,用半定量RT-PCR检测细胞中RANTES mRNA水平,用ELISA法测定细胞培养上清中RANTES蛋白水平。结果格列喹酮干预组HRMC RANTES的mRNA表达和蛋白分泌低于AGE-BSA组（P〈0.05）,且降低水平呈浓度和时间依赖性。结论格列喹酮能抑制糖基化终产物诱导的HRMC RANTES的表达和分泌。     

Deletion of bone-marrow-derived receptor for AGEs (RAGE) improves renal function in an experimental mouse model of diabetes

Aims/hypothesis

The AGEs and the receptor for AGEs (RAGE) are known contributors to diabetic complications. RAGE also has a physiological role in innate and adaptive immunity and is expressed on immune cells. The aim of this study was to determine whether deletion of RAGE from bone-marrow-derived cells influences the pathogenesis of experimental diabetic nephropathy.

Methods

Groups (n?=?8/group) of lethally irradiated 8 week old wild-type (WT) mice were reconstituted with bone marrow from WT (WT?→?WT) or RAGE-deficient (RG) mice (RG?→?WT). Diabetes was induced using multiple low doses of streptozotocin after 8 weeks of bone marrow reconstitution and mice were followed for a further 24 weeks.

Results

Compared with diabetic WT mice reconstituted with WT bone marrow, diabetic WT mice reconstituted with RG bone marrow had lower urinary albumin excretion and podocyte loss, more normal creatinine clearance and less tubulo-interstitial injury and fibrosis. However, glomerular collagen IV deposition, glomerulosclerosis and cortical levels of TGF-β were not different among diabetic mouse groups. The renal tubulo-interstitium of diabetic RG?→?WT mice also contained fewer infiltrating CD68⁺ macrophages that were activated. Diabetic RG?→?WT mice had lower renal cortical concentrations of CC chemokine ligand 2 (CCL2), macrophage inhibitory factor (MIF) and IL-6 than diabetic WT?→?WT mice. Renal cortical RAGE ligands S100 calgranulin (S100A)8/9 and AGEs, but not high mobility box protein B-1 (HMGB-1) were also decreased in diabetic RG?→?WT compared with diabetic WT?→?WT mice. In vitro, bone-marrow-derived macrophages from WT but not RG mice stimulated collagen IV production in cultured proximal tubule cells.

Conclusions/interpretation

These studies suggest that RAGE expression on haemopoietically derived immune cells contributes to the functional changes seen in diabetic nephropathy by promoting macrophage infiltration and renal tubulo-interstitial damage.     

Role of advanced glycation end products (AGEs) and receptor for AGEs (RAGE) in vascular damage in diabetes

A non-enzymatic reaction between ketones or aldehydes and the amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules and to the development and progression of various age-related disorders such as vascular complications of diabetes, Alzheimer's disease, cancer growth and metastasis, insulin resistance and degenerative bone disease. Under hyperglycemic and/or oxidative stress conditions, this process begins with the conversion of reversible Schiff base adducts, and then to more stable, covalently-bound Amadori rearrangement products. Over a course of days to weeks, these early glycation products undergo further reactions and rearrangements to become irreversibly crossed-linked, fluorescent protein derivatives termed advanced glycation end products (AGEs). There is a growing body of evidence that AGE and their receptor RAGE (receptor for AGEs) interaction elicits oxidative stress, inflammatory reactions and thrombosis, thereby being involved in vascular aging and damage. These observations suggest that the AGE-RAGE system is a novel therapeutic target for preventing diabetic vascular complications. In this paper, we review the pathophysiological role of the AGE-RAGE-oxidative stress system and its therapeutic intervention in vascular damage in diabetes. We also discuss here the potential utility of the restriction of food-derived AGEs in diabetic vascular complications.     

AGEs对免疫细胞作用的研究进展

糖尿病患者长期高血糖导致晚期糖基化终末产物（AGEs）在体内过多蓄积，引起体内免疫系统一系列病理生理变化。AGEs可作用于巨噬细胞、淋巴细胞、树突状细胞等多种细胞，激活细胞内信号途径，促进免疫细胞分化，分泌多种细胞因子。同时，AGEs诱发体液免疫，产生抗AGEs自身抗体，共同参与糖尿病急慢性并发症的发生。     

The role of AGEs in aging: causation or correlation

Over a dozen advanced glycation end-products (AGEs) have been identified in tissue proteins by chemical or immunological methods. Of these, about half are known to accumulate with age in collagen at a rate that correlates with the half-life of the collagen. AGEs may be formed by oxidative and non-oxidative reactions and are in some cases identical to advanced lipoxidation end-products (ALEs) formed in protein during lipid peroxidation reactions. AGEs affect the biochemical and physical properties of proteins and the extracellular matrix (ECM), including the charge, hydrophobicity, turnover and elasticity of collagen, and the cell adhesion, permeability and pro-inflammatory properties of the ECM. A number of scavenger and AGE-specific receptors have been identified that may mediate the turnover of AGE-proteins, catalyze the local production of reactive oxygen species and attract and activate tissue macrophages. Although AGEs in proteins are probably correlative, rather than causative, with respect to aging, they accumulate to high levels in tissues in age-related chronic diseases, such as atherosclerosis, diabetes, arthritis and neurodegenerative disease. Inhibition of AGE formation in these diseases may limit oxidative and inflammatory damage in tissues, retarding the progression of pathophysiology and improve the quality of life during aging.     

AGEs,RAGE, and Diabetic Retinopathy

Diabetic retinopathy is a major diabetic complication with a highly complex etiology. Although there are many pathways involved, it has become established that chronic exposure of the retina to hyperglycemia gives rise to accumulation of advanced glycation end products (AGEs) that play an important role in retinopathy. In addition, the receptor for AGEs (RAGE) is ubiquitously expressed in various retinal cells and is upregulated in the retinas of diabetic patients, resulting in activation of pro-oxidant and proinflammatory signaling pathways. This AGE-RAGE axis appears to play a central role in the sustained inflammation, neurodegeneration, and retinal microvascular dysfunction occurring during diabetic retinopathy. The nature of AGE formation and RAGE signaling bring forward possibilities for therapeutic intervention. The multiple components of the AGE-RAGE axis, including signal transduction, formation of ligands, and the end-point effectors, may be promising targets for strategies to treat diabetic retinopathy.     

Olmesartan blocks advanced glycation end products (AGEs)-induced angiogenesis in vitro by suppressing receptor for AGEs (RAGE) expression

We have previously shown that advanced glycation end products (AGEs)-their receptor (RAGE) interaction elicits angiogenesis through autocrine production of vascular endothelial growth factor (VEGF), thus suggesting the active involvement of the AGEs-RAGE system in proliferative diabetic retinopathy (PDR). Since the crosstalk between the AGEs-RAGE and the renin-angiotensin system has also been proposed in the pathogenesis of PDR, we investigated here whether olmesartan, an angiotensin II type 1 receptor blocker, inhibited the AGEs-elicited angiogenesis in vitro by suppressing the NF-kappaB-mediated RAGE expression. Olmesartan significantly inhibited the AGEs-induced NF-kappaB promoter activity and RAGE gene expression in cultured microvascular endothelial cells (ECs). Further, olmesartan was found to block the AGEs-induced up-regulation of VEGF mRNA levels and consequent increase in DNA synthesis in ECs. These results demonstrated for the first time that olmesartan inhibited the AGEs signaling to angiogenesis by suppressing RAGE expression in ECs. Our present study suggests that blockade of the renin-angiotensin system by olmesartan may play a protective role against PDR by attenuating the deleterious effects of AGEs via down-regulation of RAGE.     

糖基化终末产物对人脐静脉内皮细胞凋亡及其受体表达的影响

目的 研究糖基化终末产物(AGEs)对人脐静脉内皮细胞(HUVEC)凋亡及其受体(RAGE)表达的影响。方法 采用流式细胞仪技术，荧光显微镜，电镜观察AGEs对培养的HUVEC凋亡的影响，同时用RT-PCR方法检测RAGE的mRNA的表达。结果 AGEs加入细胞培养中，可明显诱导HUVEC凋亡，并呈剂量依赖效应关系。在发生凋亡的同时有RAGE mRNA表达的增强。结论 AGEs对HUVEC有诱导凋亡的作用，该作用可能通过RAGE介导。