[ ABSTRACT] 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.

Objective:To investigate levels of autophagy in T cells and B cell of patients with systemic lupus erythematosus ( SLE) and its clinical significance.Methods: 68 SLE patients without treatment within 4 weeks were enrolled in this study.We accessed the levels of autophagy in T cells and B cells of 23 healthy controls and 68 patients before and after treatment by flow cytometry,and analyzed their correlations with serum levels of C3 and anti-dsDNA antibodies,SLEDAI score,et al.Results: Before treatment,a significantly increased levels of LC3-Ⅱ was observed in SLE patients than healthy controls, the active group ( SLEDAI score≥10) was significantly higher than the stable group(SLEDAI score<10),and the newly diagnosed group was significantly higher than the recurrent group(all P<0.05).While the levels of LC3-Ⅱ was decreased in B lymphocytes in SLE patients,the active group was significantly lower than stable group,and the active group was significantly lower than the newly diagnosed group(all P<0.05). Correlation analysis found that,a positively correlation was observed for the levels of LC3-Ⅱwith SLEDAI score in T lymphocyte( rs=0.289,P<0.05),and the levels of C3 were positively correlated the levels of LC3-Ⅱ in B lymphocyte(rs=0.371,P<0.01).After treatment for five days, levels of autophagy in T lymphocytes of SLE patients with good prognosis ( SLEDAI score decreased ≥4 ) significantly decreased(P<0.05).Also,three days after treatment,levels of autophagy in B lymphocytes of SLE patients with good prognosis were increased significantly ( P<0.05 ) .However, SLE patients with poor prognosis had no such difference ( P>0.05 ) . Conclusion:Levels of autophagy in T and B lymphocytes of SLE patients are abnormal compared to healthy controls,and these changes are associated with disease activity.Also,these changes are expected to be the indicators of disease activity and potential therapeutic targets in SLE.