β-adrenoceptor activation induces the apoptosis of human mesangial cells

Objective To investigate the effects of β-adrenoceptor (β-AR) activation on the apoptosis in human mesangial cells and it' s mechanism. Methods Cultured HMC were used in experiments and were divied into four groups: the control group; β-AR activation (β-AR agonist NE/Pra) group; β-AR inhibitor (Prop) group; antioxidants group. The experiments technology including PCR, confocal scanning microscope, immunofluorescence and Tunel. Results The results of RT-PCR and confocal scanning microscope showed that β1-AR and β2-AR were expressed in human HMC. β-AR activation induced reactive oxygen species (ROS) increase in human MCs, the relative levels of ROS were elevated as early as 0.5 h after β-AR activation, and gradually increased and peaked at 4 h on a concentration and time dependent manner. Tunel results demonstrated that β-AR activation induced apoptosis with ROS on a concentration and time dependent manner, β-AR blocking agent-propranolol significantly inhibited β-AR activation induced apoptosis. Antioxidants including vitamin C and NAC could inhibited β-AR activation induced apoptosis (all P <0.01). Conclusions β-AR is functionally expressed in human mesangial cell, furthermore β-AR activation-induced ROS increase mediate apoptosis. Antioxidants can inhibit β-AR activation induced apoptosis. Key words: Mesangial cell; Sympathetic nerve system; Apoptosis; Oxidative stress