To investigate the protective effect of berberine in podocyte injury and cytoskeleton change induced by high glucose and advanced glycosylation end-products (AGE).

The conditionally immortalized human glomerular podocytes were used for study, and cultured in RPMI 1640 medium containing 10% fetal bovine serum and 100 U/L gamma-interferon. After proliferation and differentiation induction, the podocytes were treated for 48 hours in groups, including high glucose (30 mM) group, AGE (100 μg/mL) group, and berberine (10 μM) group, respectively. The changes of F-actin and G-actin in podocytes were observed with laser confocal microscope; and the expressions of capase-3 and nephrin were detected with in-situ immunocytochemistry. For statistical analysis, the SPSS13.0 statistical software package was used.

The laser confocal microscope showed that F-actin reorganized, and G-actin dislocated in the high glucose plus AGE group, which recovered partly after berberine treatment. Immunohistochemical results showed that the control group and the high glucose group hardly displayed any positive expression of capase-3. But the high glucosre plus AGE group displayed positive expression of capase-3 (F=99.339, P< 0.001), and significantly decreased expression of nephrin (F=165.84, P<0.001), the differences of which were statistically significant compared with those of the control group and the high glucose group. After treatment with berberine, the high glucose plus AGE group showed lower expression of capase-3 (F=6.927, P=0.048), but higher expression of nephrin (F=165.84, P=0.025), the differences of which were statistically significant.

High glucose and AGE induced F-actin reoganization and G-actin dislocation, and stimulated apoptosis in podocytes, which were inhibited by berberine, whose mechanism may involve the participation of nephrin.