RESUMEN
To compare the stimulation and binding characteristics of adenosine analogs including AMP, IMM-H007, and M1, to AMPK, and to explore the potential mechanism underlying the regulation effect of adenosine analogs on AMPK activity, [γ-32P]ATP assay, circular dichroism experiments and molecular docking test were performed. We found that the interactions with Thr86, Thr88, and His150 in site 1 are probably the reason why the affinities of IMM-H007, M1, and adenosine are comparable but their allosteric activation on AMPK varies greatly, partly interpreting the mechanism of AMPK activity regulated by adenosine analogs.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacología , Adenosina/química , Animales , Sitios de Unión , Dicroismo Circular , Regulación de la Expresión Génica/efectos de los fármacos , Modelos Moleculares , Simulación del Acoplamiento Molecular , Estructura Molecular , Unión Proteica , Ratas , Ratas Sprague-DawleyRESUMEN
Rheumatoid arthritis (RA) is a degenerative joint disease that is caused by multiple pathogenic factors. However, the precise etiology of RA is still unknown. Our previous studies demonstrated that acid-sensing ion channel 1a (ASIC1a)-mediated articular chondrocyte apoptosis played a key role in the progression of RA. In this study, we aim to explore whether ASIC1a mediates autophagy or not and the effect of autophagy on ASIC1a-mediated apoptosis. Primary articular chondrocytes, extracted from rat knee joints, were exposed to different concentrations of concentrated hydrochloric acid for different time intervals in vitro. The results indicated that extracellular acid treatment induced autophagy of rat articular chondrocytes. Moreover, inhibition of ASIC1a with either psalmotoxin 1 or ASIC1a short hairpin RNA reduced the autophagy flux. The results suggested that ASIC1a mediated acid-induced autophagy. Pretreatment with autophagy antagonist 3-methyladenine decreased the autophagy, but increased the apoptosis mediated by ASIC1a. Furthermore, knockdown of Beclin 1 by small interfering RNA attenuated autophagy but potentiated ASIC1a-mediated apoptosis of rat articular chondrocytes. Taken together, these findings suggested that both inhibition and silencing of autophagy could enhance ASIC1a-mediated apoptosis in rat articular chondrocytes, and therefore, autophagy is likely to be a new mechanism involved in ASIC1a-mediated apoptosis of articular chondrocytes during the pathogenesis of RA.
