结缔组织生长因子在高糖诱导的足细胞上皮间充质转化中的作用

目的: 研究结缔组织生长因子(CTGF)在高糖诱导的足细胞上皮间充质转化(EMT)中的作用。方法: 将在分化条件下的足细胞分为正常葡萄糖(5 mmol/L)培养组、正常葡萄糖+CTGF(50 μg/L)组、高糖(30 mmol/L)培养组和高糖+CTGF组,在37 ℃条件下刺激24 h。用相差显微镜观察足细胞形态,分别用real-time RT-PCR和Western blotting方法检测足细胞相关EMT指标。同时用抗CTGF抗体和高糖共同培养足细胞,检测其对足细胞EMT的影响。结果: 高糖培养时,足细胞表型发生改变,由正常情况下的树枝状变为鹅卵石状,CTGF与高糖共同培养,进一步使足细胞发生梭形改变。高糖作用下,足细胞发生EMT,上皮细胞标志物nephrin表达减少,间充质细胞标志物desmin表达增加,CTGF和高糖协同作用,使足细胞EMT更加明显,而抗CTGF抗体能抑制高糖诱导的足细胞EMT。结论: CTGF参与了高糖诱导的足细胞EMT的发生过程,阻断CTGF能减轻此病理变化而发挥足细胞保护作用。

Role of connective tissue growth factor in high glucose-induced epithelial-mesenchymal transition in podocytes

AIM: To investigate the role of connective tissue growth factor (CTGF) in high glucose-induced epithelial-mesenchymal transition (EMT) in podocytes. METHODS: The differentiated podocytes cultured under different conditions for 24 h at 37 ℃ were divided into 4 groups: control (5 mmol/L glucose solution), 5 mmol/L glucose solution supplemented with 50 μg/L CTGF, high glucose (30 mmol/L glucose solution) and high glucose supplemented with CTGF (50 μg/L). The morphology of cultured podocytes was observed under phase-contrast microscope. To study the relevant markers of EMT, the mRNA and protein expression was analyzed by real-time RT-PCR and Western blotting, respectively. In addition, the effect of CTGF inhibition with anti-CTGF antibody on high glucose-induced EMT in podocytes was investigated. RESULTS: High glucose induced phenotypic transition in the podocytes from an arborization morphology to a cobblestone morphology. After addition of CTGF to high glucose culture, the podocytes developed a feature of spindle. Under high glucose condition, podocytes underwent EMT, as the epithelial marker (nephrin) was decreased and the mesenchymal marker (desmin) was increased. Exogenous CTGF showed the effect of synergy on high glucose-induced EMT. Moreover, high glucose-induced EMT in podocytes was prevented by CTGF inhibition with anti-CTGF antibody. CONCLUSION: CTGF is involved in high glucose-induced EMT in podocytes. Inhibition of CTGF might prevent podocytes from injury in diabetes.