Connective tissue growth factor mediates high glucose-induced down-regulation of podocalyxin expression in mouse podocytes / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To detect the effect of connective tissue growth factor (CTGF) on podocalyxin expression in mouse podocytes exposed to high glucose in vitro and explore the possible pathway involved.</p><p><b>METHODS</b>The expression vector carrying a small interfering RNA (siRNA) targeting CTGF was transfected into mouse podocytes cultured in the presence of 1 g/L glucose (normal control), 4.5 g/L glucose (high glucose group), 1 g/L glucose + 3.5 g/L mannitol (iso-osmolar control group). The changes in the protein expression levels of podocalyxin, CTGF and ERK1/2 in the cells in response to the treatments were investigated using Western blotting.</p><p><b>RESULTS</b>High glucose exposure for 24 and 48 h resulted in significantly decreased expression of podocalyxin and increased CTGF in the podocytes (P<0.05). Phosphorylation of ERK1/2 occurred as early as 30 min after the exposure, and the activation was maintained till 24 h. Transfection of the cells with siRNA targeting CTGF significantly inhibited these changes.</p><p><b>CONCLUSION</b>CTGF is an important mediator of high glucose-induced podocyte damage and decreases the protein level of podocalyxin by the ERK1/2 pathway. CTGF-specific siRNA can alleviate high glucose-induced podocyte injury, suggesting its potential value in treatment of diabetic nephropathy.</p>