CD2AP在肾脏病学的研究进展

CD2AP是新发现的一种肾小球足细胞裂孔膜蛋白。CD2AP / 小鼠表现为先天性肾病综合症,出生后6~7周将死于肾功能衰竭;CD2AP / 小鼠肾脏病理表现类似于人类FSGS。CD2AP基因突变可能与人类一些肾脏疾病的发病有关。此外,CD2AP还可能通过与其他裂孔膜蛋白相互作用,在足细胞信号转导和功能调节过程中发挥重要作用。     

miR-55表达变化对TGF-β损伤足细胞蛋白podocin、CD2AP、synaptopo-din的影响

目的:研究miR-155 mimics/inihibitor转染足细胞后微小RNA-155(miR-155)的表达变化及其对TGF-β1损伤足细胞的影响.方法:体外培养小鼠足细胞,细胞免疫荧光染色鉴定足细胞分化成熟;用TGF-β1处理足细胞构建足细胞损伤模型,RT-PCR和Western blot分别检测miR-155...     

CD2相关蛋白在肾病综合征中的表达及意义

目的观察不同病理类型的原发性肾病综合征(nephrotic syndrome,NS)患者肾小球足细胞中CD2相关蛋白(CD2AP)的表达,探讨其与足细胞损伤的关系。方法选取原发性NS患者54例,10例同期肾肿瘤切除患者正常肾组织作为对照。肾活检后常规染色观察肾脏组织病理改变,肾组织行免疫荧光法CD2AP和肾小球上皮细胞蛋白-1(GLEPP1)双重标记,对肾小球CD2AP的表达进行定位;分别用real time PCR和免疫组化SP法检测组织中CD2AP的表达,采用real time PCR检测nephrin的表达,透射电镜观察足细胞的结构变化,并定量测量足突密度。结果 (1)NS患者肾小球中CD2AP的表达及nephrin的表达下调,足细胞足突不同程度融合,足突密度降低。(2)病理表现为微小病变性肾病(minimal change disease,MCD)、局灶性节段性肾小球硬化(focal segmental glomerulosclerosis,FSGS)和膜性肾病(membranous nephropathy,MN)的NS患者CD2AP表达及nephrin表达较对照组明显降低,且CD2AP与nephrin表达呈正相关,病理表现为MCD和FSGS的NS患者CD2AP表达与足突密度呈正相关。结论本研究首次发现原发性NS患者肾小球足细胞中CD2AP的表达降低,且在MCD和FSGS中与足细胞病变程度相关,提示CD2AP低表达在足细胞病变为主的肾小球疾病中发挥重要作用。CD2AP有利于诊断足细胞病变的早期检测,对CD2AP表达减低进行早期干预可能有助于延缓疾病进展。     

CD2相关蛋白在肾脏细胞中的分布及其在足细胞中的作用

目的 观察CD2相关蛋白(cD2AP)在肾脏不同细胞系中的表达分布,及其与足细胞裂孔隔膜分子nephrin和细胞骨架蛋白F-actin之间的联系.方法 以DMEM培养基培养人肾小球系膜细胞(HMC)和人肾小管上皮细胞系(HK-2),RPMI 1640培养基培养条件永生化小鼠足细胞系.以RT-PCR及Western blotting方法检测足细胞内CD2AP和nephrin的表达.间接免疫荧光结合激光共焦方法观察CD2AP在HMC、HK-2、未分化及已分化足细胞中的表达情况,及CD2AP与nephtin在足细胞中的共存.直接免疫荧光结合激光共焦方法观察F-actin在足细胞的表达及其与CD2AP的共存.结果 CD2AP均匀分布于HK-2及未分化足细胞的核周及胞浆,而不表达于HMC细胞.在足细胞分化过程中,CD2AP的分布发生了变化,出现向周边聚集的现象.CD2AP与足细胞裂孔隔膜分子nephrin及细胞骨架蛋白F-actin在足细胞中存在共定位关系.结论 CD2AP表达于上皮来源的肾脏固有细胞.CD2AP在足细胞中的分布特点,提示CD2AP可能参与足细胞的分化过程,并与裂孔隔膜分子功能及细胞骨架凋节有关.     

蟾蜍干预对大鼠肾病模型CD2AP表达的影响

目的 探讨CD2-associated protein（CD2AP）在蟾蜍干预阿霉素肾病模型肾小球中的表达及意义。方法 通过建立阿霉素（ADR）肾病模型，用蟾蜍等干预后，采用免疫组织化学技术观察各组模型大鼠肾小球中CD2AP的表达变化。结果 蟾蜍能使肾小球足细胞CD2AP的表达上调。结论 蟾蜍对肾病大鼠模型病理损伤的修复可能与CD2AP表达上调有关。     

Podocin及其生物学意义

Podocin是一种新发现的肾小球足细胞跨膜蛋白 ,定位于足突裂孔隔膜 (SD)插入足突膜的部位。Podocin属于stomatin蛋白家族 ,可能具有离子通道、信号转导功能 ,在足细胞形态形成和SD结构组织与功能调节中发挥重要作用。     

CD3、CD4、COX-2在非小细胞肺癌中的表达及意义

目的:探讨非小细胞肺癌(NSCLC)组织中CD3、CD4及环氧化酶-2(COX-2)的表达及临床意义。方法:用免疫组化法检测37例NSCLC手术标本中CD3、CD4、COX-2的表达情况,用Spearman秩和检验分析它们与患者总生存(OS)间的关系。结果:NSCLC患者组织中CD3平均面密度、CD4平均光密度均与患者OS相关(P<0.05),CD3高表达者OS较长,CD4低表达者OS更长。COX-2表达与患者术后生存时间无关(P>0.05)。结论:CD3表达越强,患者术后OS时间越长;CD4表达越强,患者术后生存时间越短;COX-2的表达强度与患者生存时间无明显相关。     

Expression of CD2AP on podocytes with different pathological types of nephrotic syndrome

目的 观察不同病理类型的原发性肾病综合征(nephrotic syndrome,NS)患者肾小球足细胞中CD2相关蛋白(CD2AP)的表达,探讨其与足细胞损伤的关系.方法 选取原发性NS患者54例,10例同期肾肿瘤切除患者正常肾组织作为对照.肾活检后常规染色观察肾脏组织病理改变,肾组织行免疫荧光法CD2AP和肾小球上皮细胞蛋白-1(GLEPP1)双重标记,对肾小球CD2AP的表达进行定位;分别用real time PCR和免疫组化SP法检测组织中CD2AP的表达,采用real time PCR检测nephrin的表达,透射电镜观察足细胞的结构变化,并定量测量足突密度.结果 (1)NS患者肾小球中CD2AP的表达及nephrin的表达下调,足细胞足突不同程度融合,足突密度降低.(2)病理表现为微小病变性肾病(minimal change disease,MCD)、局灶性节段性肾小球硬化(focal segmental glomerulosclerosis,FSGS)和膜性肾病(membranous nephropathy,MN)的NS患者CD2AP表达及nephrin表达较对照组明显降低,且CD2AP与nephrin表达呈正相关,病理表现为MCD和FSGS的NS患者CD2AP表达与足突密度呈正相关.结论 本研究首次发现原发性NS患者肾小球足细胞中CD2AP的表达降低,且在MCD和FSGS中与足细胞病变程度相关,提示CD2AP低表达在足细胞病变为主的肾小球疾病中发挥重要作用.CD2AP有利于诊断足细胞病变的早期检测,对CD2AP表达减低进行早期干预可能有助于延缓疾病进展.     

T细胞CD2活化途径研究进展

Ｔ细胞ＣＤ２活化途径是Ｔ细胞激活的非特异途径，Ｔ细胞表面分化抗原ＣＤ２分子与其配体ＬＡＦ－３相互作用，不仅介导了Ｔ细胞与其他细胞之间非抗原依赖的粘附，激活，尚参与胸腺细胞的分化，发育，调控Ｔ细胞细胞因子产生及诱导免疫耐受。此外，ＣＤ２系统与某些疾病的发展，转归密切相关。     

T细胞CD2活化途径研究进展

Ｔ细胞ＣＤ２活化途径是Ｔ细胞激活的非特异途径，Ｔ细胞表面分化抗原ＣＤ２分子与其配体ＬＡＦ－３相互作用，不仅介导了Ｔ细胞与其他细胞之间非抗原依赖的粘附、激活，尚参与胸腺细胞的分化、发育，调控Ｔ细胞细胞因子产生及诱导免疫耐受。此外，ＣＤ２系统与某些疾病的发展、转归密切相关。     

Association of CD2AP neuronal deposits with Braak neurofibrillary stage in Alzheimer’s disease

Genome-wide association studies have described several genes as genetic susceptibility loci for Alzheimer's disease (AD). Among them, CD2AP encodes CD2-associated protein, a scaffold protein implicated in dynamic actin remodeling and membrane trafficking during endocytosis and cytokinesis. Although a clear link between CD2AP defects and glomerular pathology has been described, little is known about the function of CD2AP in the brain. The aim of this study was to analyze the distribution of CD2AP in the AD brain and its potential associations with tau aggregation and β-amyloid (Aβ) deposition. First, we performed immunohistochemical analysis of CD2AP expression in brain tissue from AD patients and controls (N = 60). Our results showed granular CD2AP immunoreactivity in the human brain endothelium in all samples. In AD cases, no CD2AP was found to be associated with Aβ deposits in vessels or parenchymal plaques. CD2AP neuronal inclusions similar to neurofibrillary tangles (NFT) and neuropil thread-like deposits were found only in AD samples. Moreover, immunofluorescence analysis revealed that CD2AP colocalized with pTau. Regarding CD2AP neuronal distribution, a hierarchical progression from the entorhinal to the temporal and occipital cortex was detected. We found that CD2AP immunodetection in neurons was strongly and positively associated with Braak neurofibrillary stage, independent of age and other pathological hallmarks. To further investigate the association between pTau and CD2AP, we included samples from cases of primary tauopathies (corticobasal degeneration [CBD], progressive supranuclear palsy [PSP], and Pick's disease [PiD]) in our study. Among these cases, CD2AP positivity was only found in PiD samples as neurofibrillary tangle-like and Pick body-like deposits, whereas no neuronal CD2AP deposits were detected in PSP or CBD samples, which suggested an association of CD2AP neuronal expression with 3R-Tau-diseases. In conclusion, our findings open a new road to investigate the complex cellular mechanism underlying the tangle conformation and tau pathology in the brain.     

Effects of the differential expression of ZO‐1 and ZO‐2 on podocyte structure and function

Glomerular podocytes in the kidney originate from columnar epithelial cells possessing tight junctions. During podocyte differentiation, tight junctions are replaced by slit diaphragms, which are formed between foot processes and function as a blood filtration barrier. Although the expression of most tight junction components is suppressed during podocyte differentiation, several components, including ZO‐1 and ZO‐2, are consistently expressed. We recently showed that podocyte‐specific deletion of ZO‐1 gene impaired slit diaphragm formation, leading to proteinuria and glomerular sclerosis. Here, we address the relevance of ZO‐2, whose sequence is highly similar to ZO‐1, in the maintenance of the structure and function of podocytes. In glomerular development, the spatiotemporal expression of ZO‐2 was similar to that of ZO‐1 until the capillary loop stage. Subsequently, the distribution patterns of ZO‐1 and ZO‐2 diverged at the maturation stage, when slit diaphragms are formed. This divergence could partly rely on the ability of ZO‐2 to interact with the slit diaphragm membrane proteins. Podocyte‐specific deletion of the ZO‐2 gene did not cause overt defects; however, double knockout of ZO‐1 and ZO‐2 genes accelerated the defects observed in ZO‐1 knockout mice. These results suggest that ZO‐2 plays supportive roles in the ZO‐1‐dependent regulation of podocyte filtration barrier.     

CD2-associated protein in human urogenital system and in adult kidney tumours

We studied expression of CD2-associated protein (CD2AP) in human urogenital system and in adult kidney tumours. In the cortex of normal kidney, CD2AP was expressed in all types of tubules and in the glomeruli. Labelling was more intense in cytokeratin 7- and in Tamm–Horsfall-positive tubules than in proximal tubules. In the medulla, expression was observed in the collecting ducts. Urothelium and the epithelium of prostatic acini, seminal vesicles, seminiferous tubules, epididymal ducts, Fallopian tube, endometrium and endocervix as well as granulosa cells showed moderate to strong CD2AP positivity. In syncytiotrophoblast, the expression was weaker than in cytotrophoblast. Endometrial stroma was negative, but decidualised stroma was weakly positive. Clear cell renal cell carcinoma (RCC) (n=63) showed a weak expression. Type-I papillary RCCs (n=4) and papillary adenomas (n=3) were negative. The epithelium lining the cysts in multilocular cystic RCCs (n=3) and in cystic nephroma (n=1) was strongly positive. Chromophobe RCCs (n=2), oncocytomas (n=3) and urothelial carcinomas (n=2) were moderately positive. The results show that CD2AP displays a specific expression pattern in human urogenital organs and that distinct expression is shown in several types of kidney tumours but not in type-I papillary RCCs or in papillary adenomas.     

Investigating the functional role of CD2BP2 in T cells

The adaptor protein CD2-binding protein 2 (CD2BP2) confers binding to proline-rich sequences (PRS) via its GYF domain. In addition to the cytoplasmic domain of CD2, several other proteins were identified as interaction partners of CD2BP2, but the in vivo significance of these findings is unclear. We now show that CD2BP2's nuclear localization is not changed when CD2 and CD2BP2 are co-expressed in HeLa cells, indicating that other PRS compete effectively for CD2BP2 binding in the nucleus. Since the CD2BP2-binding motifs of CD2 are known to be involved in cytokine signaling, we tested the effect of CD2BP2 knockdown in PBMCs on the expression of T-cell cytokines. No major difference in cytokine expression can be observed for primary cells transfected with CD2BP2-specific small interfering RNA. We conclude that CD2 signaling is at least partially independent of its in vitro binding partner CD2BP2.     

Enhanced murine CD4+ T cell responses induced by the CD2 ligand CD48

The physiological functions of murine CD2 and its ligand CD48 are uncertain. We have examined the role of the CD2-CD48 interaction in murine T cell activation using a series of Chinese hamster ovary (CHO) cell transfectants. CHO cells expressing I-A^d together with CD48 induced more potent activation of OVA-specific, I-A^d -restricted DO11.10-transgenic T cells than CHO cells expressing I-A^d alone. CD48 augmented proliferation and IL-2 production in response to antigen. The enhancing effect of CD48 was of the same magnitude as that seen for CD80 (B7-1). Conjugate assays revealed the ability of CD48 to increase adhesion between T cells and CHO transfectants. The enhancing effects of CD48 on T cell-antigen-presenting cell adhesion and T cell activation were inhibited by anti-CD2 monoclonal antibody. This report provides the first evidence that the CD2 ligand CD48 contributes to the interactions of murine CD4⁺ T cells with antigen-presenting cells.     

Genetic analysis of CD28 signaling

T cell activation is central to initiating an immune response. Two signals are required: an antigen-specific signal through the T cell receptor (TCR) and an antigen-independent costimulatory signal, primarily through CD28 in naïve T cells. Although many of the molecules involved in TCR signal transduction have been identified, the signaling pathways downstream of CD28 involved in costimulation are not well-defined. Through mutagenesis, we have generated a panel of Jurkat T cell lines in which CD28 costimulation fails to upregulate the RE/AP composite element of the IL-2 promoter. Biochemical analysis and genetic rescue of the defects in these cell lines will lead to a better understanding of CD28 signal transduction.     

高压芒刺静电场对小鼠胸腺细胞和腹腔巨噬细胞中CD2、CD48表达的影响

目的:通过时程/量效研究观察不同强度芒刺高压静电场对表面分子CD2、CD48表达的影响.材料和方法:采用不同强度芒刺高压静电场对小鼠进行全身辐射,荧光免疫流式细胞术检测小鼠胸腺细胞CD2蛋白和腹腔巨噬细胞CD48蛋白表达的变化.结果:剂量-效应结果显示,在10 kV～20 kV之间处理组的CD2、CD48表达量显著高于对照组(P＜0.01);在30 kV以上电压表达量明显低于对照组(P＜0.01);15 kV电压时间进程研究结果表明,CD2于处理后2 h表达开始增加,在4 h～8 h表达量达到高峰,与对照组比较差异显著(P＜0.001),24 h时表达量趋于恢复,接近对照组;CD48于处理后4 h开始增加,高峰出现在8 h,与对照组比较差异显著(P＜0.001),24 h时的表达量接近对照组;35 kV电压时间进程研究结果表明,CD2于处理后2 h表达量即达到最低值,之后表达量逐步回升,但持续到24 h未能恢复到对照组水平;CD48表达量的下降晚于CD2,在4 h开始下降,最低值出现在处理后8 h,其后逐步回升.结论:不同强度高压芒刺静电场可引起CD2、CD48表达量不同的生物效应,二者的相互作用在免疫调节反应中发挥重要功能.