The expression change of autophagy-related factors in lens epithelial cells of diabetic mice

Abstract

Objective To investigate the role of autophagy in the development of diabetic cataract by detecting the expression of autophagy-related factors (BECN1, LC3B, P62) in diabetic mouse lens epithelial cells. Methods Eighty C57BL/6 male mice were selected.Fifty C57 mice were consecutively dosed with streptozotocin (STZ) 50 mg/(kg·d) by intraperitoneal injection to induce type 1 diabetes mellitus model, and served as the model group; the remaining 30 mice were injected with appropriate dose of citrate buffer, and served as the control group.The fasting plasma glucose was tested by collecting the caudal vein blood in the model group.The morphological changes of autophagy of lens epithelial cells were observed by transmission electron microscopy.The expression and localization of LC3B and P62 protein were detected by immunohistochemistry.PCR was used to detect the expression of BECN1, LC3B and P62 mRNA in the anterior capsule.The relative expression of autophagy-related proteins in the anterior capsule was detected by Western blot.The use of animals complied with Regulations on the Management of Experimental Ainimals from Shandong Eye Institute. Results Compared with the control group, transmission electron microscopy revealed that the autophagosomes of lens epithelial cells in model group was large and contained more mitochondria.Immunohistochemical method showed that the expression of LC3B and P62 proteins in the anterior capsule tissue of experiment group was stronger than that of the control group.The relative expression level of BECN1, LC3B and P62 mRNA in the experiment group was 1.48±0.10, 2.62±0.15 and 1.89±0.20, respectively, which was higher than 1.10±0.02, 1.10±0.05 and 1.01±0.01 in the control group, with significant differences between the two groups (t=6.64, 14.25, 6.14; all at P<0.05). The relative expression of BECN1, LC3B and P62 protein in the experiment group was 1.50±0.10, 1.24±0.09 and 3.19±1.04, respectively, which was higher than 1.00±0.00, 1.00±0.00 and 1.00±0.00 in the control group, with significant differences between the two groups (t=8.75, 6.10, 3.65; all at P<0.05). Conclusions The phenomenon of autophagy in lens epithelial cells of diabetic mice is abnormal, and autophagy dysfunction may play an important role in the formation of diabetic cataract. Key words: Diabetic cataract; Autophagy; Lens epithelial cells; BECN1; LC3B; P62