Klotho promotes high-glucose-mediated autophagy of human renal tubule cells / 中国医师杂志

ABSTRACT

Objective:To investigate the effects of Klotho on autophagy of human renal tubule cells under high glucose through AMP-activated protein kinase (AMPK) and extracellular signal regulated kinase (ERK) pathways.Methods:Human renal tubular epithelial cells cultured in vitro were divided into control group and high glucose group (HG group, added with 30 mmol/L glucose); According to the transfection of pcDNA3.1-vector or pcDNA3.1-Klotho, they were divided into two groups Vector group and Klotho group; According to whether AMPK inhibitor compound C or ERK inhibitor curcumin was added after pcDNA3.1-Klotho transfection and high glucose stimulation, they were divided into four groups HG+ Vector group, HG+ Klotho group, HG+ Klotho+ compound C group and HG+ Klotho+ curcumin group. The expression of Klotho was detected by real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and Western blot; The relative expression of LC3-Ⅱ/LC3-Ⅰ and p-AMPK/AMPK and p-ERK/ERK were detected by Western blot; Changes of autophagosome in human renal tubular epithelial cells observed by transmission electron microscope. Results:The protein and mRNA expression of Klotho in human renal tubular epithelial cells of HG group was significantly lower than that in the control group (all P<0.05); The LC3-Ⅱ/LC3-Ⅰ in Klotho group was significantly higher than that in Vector group ( P<0.05); The number of autophagosomes in Klotho group was also significantly higher than that in Vector group ( P<0.05); p-AMPK/AMPK in Klotho group was significantly higher than that in Vector group ( P<0.05), while p-ERK/ERK in Klotho group was significantly lower than that in Vector group ( P<0.05). The protein relative expression of p-AMPK/AMPK in HG+ Klotho+ compound C group (0.44±0.04) was significantly lower than that in HG+ Klotho group (0.79±0.08) ( P<0.01); The protein relative expression of p-ERK/ERK in HG+ Klotho+ curcumin group (1.05±0.12) was significantly higher than that in HG+ Klotho group (0.56±0.05) ( P<0.01). The relative expression of LC3-Ⅱ/LC3-Ⅰ protein in HG+ Klotho+ compound C group and HG+ Klotho+ curcumin group (0.79±0.12; 0.68±0.09) were significantly lower than that in HG+ Klotho group (1.65±0.20) (all P<0.01). Conclusions:Klotho can enhance autophagy of human renal tubular epithelial cells under high glucose condition by activating AMPK and inhibiting ERK pathway.