尿蛋白及晚期糖基化终产物对肾小管上皮细胞溶酶体的影响  

Effect of urinary proteins and advanced glycosylation end products on lysosomes in renal tubular epithelial cells

作　　者：邓健锟 王淑君[1] 吴洪銮 罗勉娜[1] 许碧华[1] 梁东[1] 潘庆军[1] 刘华锋[1] 刘伟敬[1] 

机构地区：[1]广东医学院附属医院肾脏疾病研究所,广东湛江524001

出　　处：《中国病理生理杂志》2015年第3期505-510,共6页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81270798);广东省自然科学基金资助项目(No.S2012040006276);广东省医学科研基金资助项目(No.A2014480);湛江市科技攻关计划(No.2013B01056);广东医学科研基金(No;m2011009)

摘　　要：目的:探讨慢性肾脏病(CKD)病程中所产生的病理产物尿蛋白及晚期糖基化终产物(AGE)对肾小管上皮细胞(tubular epithelial cells,TECs)溶酶体结构与功能的影响,为阻止或延缓CKD病情进展探索新思路。方法:临床上选取未经特殊治疗的微小病变肾病综合征(MCNS)患者(n=11)、糖尿病肾病(DN)患者(n=11)及活检基本正常(n=6)的肾组织标本,以溶酶体相关膜蛋白1(lysosomal-associated membrane protein 1,LAMP1)和组织蛋白酶B(cathepsin B,CB)行间接免疫荧光染色;体外以8 g/LJ尿蛋白或100 mg/L晚期糖基化终产物刺激人肾小管上皮细胞系(HK-2细胞),以LAMP1和CB行间接免疫荧光染色,检测CB及组织蛋白酶L(cathepsin L,CL)活性,并观察DQ-卵清蛋白降解情况。结果:MCNS及DN患者TECs存在溶酶体膜透化(lysosomal membrane permeabilization,LMP)现象。与正常对照组相比,尿蛋白及AGE-BSA均可致HK-2细胞LMP发生率上升,CB及CL活性降低,溶酶体对DQ-卵清蛋白的降解能力降低(P<0.05)。结论:CKD病理产物尿蛋白和晚期糖基化终产物均可致TECs出现LMP现象,并使溶酶体消化功能下降,这可能是CKD肾小管间质纤维化进展的重要机制之一。AIM：To investigate the effects of pathological products, urinary proteins and advanced glycosyla-tion end products （ AGE） produced in the progression of chronic kidney disease （ CKD） , on the structure and function of lysosomes in renal tubular epithelial cells （ TECs ） , and try to find a novel approach for preventing or delaying CKD. METHODS：The renal specimens of the untreated patients with minimal change nephrotic syndrome （MCNS）, diabetic nephropathy （DN） or normal kidney were collected.The expression of lysosomal-associated membrane protein 1 （LAMP1） and cathepsin B （ CB） was studied in TECs by indirect immunofluorescent staining.Human renal tubular epithelial cell line HK-2 was incubated with 8 g/L urinary proteins or 100 mg/L AGE.The expression of LAMP1 and CB was investigated by indirect immunofluorescence and the activity of CB and cathepsin L （ CL） was measured by biochemical and enzymatic as-says.The degradation of DQ-ovalbumin was also determined.RESULTS： The lysosomal membrane permeabilization oc-curred in the TECs of MCNS and DN patients.After treatment with urinary proteins or AGE-BSA, the lysosomal membrane permeabilization of the HK-2 cells was increased.The activity of CB and CL and degradation of DQ-ovalbumin were de-creased as compared with normal control group.CONCLUSION：The digestive function of lysosome was decreased and ly-sosomal membrane permeabilization occurred in the TECs exposed to urinary proteins and AGE, which might be a key factor to induce the tubulointerstitial fibrosis.

关 键 词：肾小管上皮细胞 溶酶体 尿蛋白 晚期糖基化终产物 

分 类 号：R363.21[医药卫生—病理学]