Antioxidant dietary deficiency induces caspase activation in chick skeletal muscle cells

Brazilian Journal of Medical and Biological Research

V.a. Nunes²  A.j. Gozzo²  M.a. Juliano¹  M. Cerqueira César¹  M.u. Sampaio²  C.a.m. Sampaio²  M.s. Araújo² 

[1] ,Universidade Federal de São Paulo Escola Paulista de Medicina Departamento de Bioquímica

关键词: Oxidative stress;    Caspase activation;    Apoptosis;    Dietary selenium deficiency;    Dietary vitamin E deficiency;    Internucleosomal DNA fragmentation;    Caspase substrate;   

DOI  :  10.1590/S0100-879X2003000800010

来源: SciELO

【 摘 要 】

Apoptosis and necrosis are two distinct forms of cell death that can occur in response to different agents and stress conditions. In order to verify if the oxidative stress induced by dietary selenium and vitamin E deficiencies can lead muscle cells to apoptosis, one-day-old chicks were reared using diets differing in their vitamin E (0 or 10 IU/kg) and selenium (0 or 0.15 ppm) supplementation. Chick skeletal muscle tissue was obtained from 28-day-old animals and used to verify apoptosis occurrence based on caspase activity detection and DNA fragmentation. Antioxidant deficiency significantly increased caspase-like activity assessed by the hydrolysis of fluorogenic peptide substrates (Abz-peptidyl-EDDnp) at lambdaexc = 320 nm and lambdaem = 420 nm. Proteolytic activation was not accompanied by typical internucleosomal DNA fragmentation detected by field inversion gel electrophoresis. Although the general caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD-fmk) (0 to 80 muM) did not block caspase-like activity when preincubated for 30 min with muscle homogenates, the hydrolyzed substrates presented the same cleavage profile in HPLC (at the aspartic acid residue) when incubated with the purified recombinant enzyme caspase-3. These data indicate that oxidative stress causes caspase-like activation in muscle cells and suggest that cell death associated with exudative diathesis (dietary deficiency of selenium and vitamin E) can follow the apoptotic pathway.

【 授权许可】

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