Effect of TNF-α on production and activation of caspase-3 in primary rat renal proximal tubule cells / 中国病理生理杂志

ABSTRACT

AIM:To investigate the production and activation of caspase-3 in primary rat renal proximal tubule cells in response to tumor necrosis factor-α(TNF-α) and the implication of nuclear factor-κB (NF-κB) in the process. METHODS:Isolated rat renal proximal tubule cells (PTCs) from male adult Sprague Dawley rats were treated with TNF-α according to the indicated time courses. A specific NF-κB inhibitor,Bay11-7082,was used alone or as a pretreatment for 1 h followed by exposure to TNF-α for 24 h.The protein levels of cleaved caspase-3,caspase-3,I-κBα,phosphorylated I-κBα,and GAPDH were detected by Western blotting using specific antibodies. RESULTS:The protein level of cleaved caspase-3 relative to caspase-3 was significantly increased in the presence of TNF-α for 6 h,12 h,and 24 h. Protein levels of caspase-3 were significantly decreased by 12 h and returned to baseline by 24 h in the presence of TNF-α. Treatment with Bay11-7082 for 25 h alone or pretreatment with Bay11-7082 for 1 h followed by addition of TNF-α for 24 h caused a remarkable reduction in both cleaved caspase-3 and caspase-3 as compared to control and TNF-α treated groups. An increase in phosphorylated I-κBα was observed from 15 min to 60 min after treatment with TNF-α at a dose of 10 μg/L in PTCs. CONCLUSION:NF-κB is not only associated with the activation of caspase-3 but also the production of caspase-3 in primary rat renal proximal tubule cells in response to TNF-α.