高表达C3aR的肥大细胞在糖尿病肾病患者肾组织中的分布及病理意义分析

选取糖尿病肾病(diabetic nephropathy,DN)早期、中期、晚期以及正常移植供肾各15例,分别作为DN早期组、中期组、晚期组和正常对照组,利用各个病例的肾穿刺组织标本进行C3aR免疫组化染色,分析各组中高表达C3aR浸润细胞的数量和分布特点,及其与DN发生、发展的关系,利用连续切片、免疫荧光双套色染色、免疫电镜、及甲苯胺蓝染色等方法对DN患者肾组织中高表达C3aR的浸润细胞进行细胞类型鉴定.结果表明:a.光镜和免疫电镜的形态学分析显示DN患者肾组织中高表达C3aR的浸润细胞在形态上具有肥大细胞的特点,免疫荧光双套色染色的分析显示,C3aR浸润细胞CD45阴性、CD68和类胰蛋白酶阳性,与肥大细胞的情况一致,甲苯胺蓝特殊染色进一步证实这是一种肥大细胞.b.正常移植供肾组织中虽有肥大细胞分布,但数量很少;从DN早期组到DN中期组,再到DN晚期组,肾组织中肥大细胞的数量有一种不断增加的趋势;DN患者肾组织肥大细胞的数量与24 h尿蛋白和血肌酐水平均具有很好的线性相关性.上述工作不仅揭示了在DN发生发展过程中肥大细胞在DN患者肾组织中的数量及分布情况,提示肥大细胞很可能参与了DN的发生发展过程,同时,DN患者肾组织肥大细胞高表达过敏毒素C3a受体C3aR的发现,提示C3a/C3aR通路很可能在DN患者肥大细胞的招募和激活过程中有重要作用.

Mast cells highly expressing C3aR were found in the kidney of diabetic nephropathy and correlated with the development of the disease

As a major complication of diabetes, diabetic nephropathy (DN) has become a major cause for end stage renal failure. Increasing evidences demonstrated that DN is a kind of inflammation disease. However, the exact mechanism is not completely elucidated. In an effort to investigate the possible role of C3aR in the development of DN, it was found unexpectedly a kind of C3aR highly expressing infiltrates in the renal tissue of patients with DN. To identify the cells and evaluate the possible role of the cells in the development of DN, forty five cases of patients with DN were selected and sections of their renal biopsy were analyzed by histological, immunohistochemical, double immunofluorescence labeling, immunoelectronicmicroscopic methods and toluidine blue staining while another 15 sections of renal biopsy from normal transplantation donor were used as normal controls. The number of C3aR highly positive cells in each section was counted and the density of the cell was calculated, and the correlation between the density of the cell and the development of DN was analyzed. Light microscopic and electron-microscopic analysis revealed that the cells were similar morphologically to mast cell. Double immunofluorescence labeling analysis demonstrated that the cells were positive in CD68 and tryptase staining while negative in CD45 staining, which is also in accordance with that of mast cells. Toluidine blue staining analysis further proved that the cells were a kind of mast cells. Only very small number of the C3aR highly positive mast cells was found in the renal biopsy of normal control group. However, the number of the cells increased with the development of DN, and correlated linearly with the urine protein level and serum creatinine. These results strongly suggested that mast cells are involved in the development of DN. C3aR might play an important role in the recruitment and activation of renal mast cell and thus contribute to the development of DN.