RESUMEN
BACKGROUND: Heavy metals can cause great harm to Siberian tigers in the natural environment. Cadmium (Cd2+) is an environmental contaminant that affects multiple cellular processes, including cell proliferation, differentiation, and survival. It has been shown to induce apoptosis in a variety of cell types and tissues. RESULTS: We investigated the apoptotic effects of Cd2+ on Siberian tiger fibroblasts in vitro. Our research revealed the typical signs of apoptosis after Cd²+ exposure. Apoptosis was dose- (0-4.8 µM) and duration-dependent (12-48 h), and proliferation was strongly inhibited. Cd²+ increased the activity of caspase-3, -8, and -9 and disrupted calcium homeostasis by causing oxidative stress and mitochondrial dysfunction. It also increased K+ efflux and altered the mRNA levels of Bax, Bcl-2, caspase-3, caspase-8, Fas, and p53. CONCLUSIONS: Our results suggest that Cd2+ triggers the apoptosis of Siberian tiger fibroblasts by disturbing intracellular homeostasis. These results will aid in our understanding of the effects of Cd2+ on Siberian tigers and in developing interventions to treat and prevent cadmium poisoning.
Asunto(s)
Animales , Cadmio/toxicidad , Apoptosis/efectos de los fármacos , Espacio Intracelular/efectos de los fármacos , Tigres , Fibroblastos/efectos de los fármacos , Homeostasis/efectos de los fármacos , Siberia , Daño del ADN , Ciclo Celular/efectos de los fármacos , Células Cultivadas , Reacción en Cadena de la Polimerasa , Especies Reactivas de Oxígeno/análisis , Apoptosis/genética , Caspasas/análisis , Caspasas/efectos de los fármacos , Ensayo Cometa/veterinaria , Microscopía Electrónica de Transmisión , Transcripción Reversa , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Fibroblastos/fisiología , Homeostasis/fisiologíaAsunto(s)
Animales , Ratas , Factor Natriurético Atrial/metabolismo , Calcio/farmacología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/enzimología , Poli(ADP-Ribosa) Polimerasas/metabolismo , Angiotensina II/farmacología , Animales Recién Nacidos , Factor Natriurético Atrial/genética , Calcio/metabolismo , Activación Enzimática/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , /metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/metabolismo , Contracción Miocárdica/efectos de los fármacos , Fosforilación/efectos de los fármacos , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Ratas Sprague-Dawley , Ribosa/metabolismoRESUMEN
The heme-regulated inhibitor (HRI), a member of the eIF-2 kinase family is crucial for regulating protein synthesis during stress. In addition to heme, stress proteins Hsp90 and Hsp70 are known to regulate HRI. The present study aims to determine the physical association of these Hsps in the regulation of HRI activation during oxidative stress using human K562 cells as a model. Extracts from the stress-induced cells were used for determining HRI kinase activity by measuring eIF-2 phosphorylation, and Hsp-HRI interaction by immunoprecipitation and immunoblot analyses. The results indicate a significant increase in both Hsp70 and Hsp90 expression during AAPH (2, 2’-azobis (2-amidinopropane) dihydrochloride)-induced oxidative stress. Further, their interaction with HRI, which correlates well with its increased HRI kinase activity leads to inhibition of protein synthesis. Thus, we demonstrate that Hsps play an important role in the regulation of initiation of protein synthesis during oxidative stress.