The present study investigated the effects of fasting and refeeding on the expression of proteasorne-related genes and their downstream targets in the skeletal muscles of chicks. Seven-day-old chicks were fasted for 2...The present study investigated the effects of fasting and refeeding on the expression of proteasorne-related genes and their downstream targets in the skeletal muscles of chicks. Seven-day-old chicks were fasted for 24 or 48 h and then refed for 4 h. The expression levels of MAFbx and MuRF1, which function as E3 ligases in the ubiquitin-proteasome system, were investigated at the mRNA and protein levels. MAFbx and MuRF1 expression were increased by fasting and these increases were downregulated by refeeding. The expression of the target proteins of these E3 ligases, MyoD and M-CK, was also analyzed. The levels of these proteins were downregulated by fasting, and these decreases were rescued by refeeding. The results of this study indicate that fasting stimulates MAFbx and MuRF1 expression in chicks, possibly leading to increased degradation of their corresponding target proteins.展开更多
文摘目的:观察人参皂苷对失神经大鼠腓肠肌MAFbx表达的影响,并探讨其延缓失神经腓肠肌萎缩的作用机制。方法:选用雌性Wistar大鼠72只,随机分为3组:假失神经组(A)24只,失神经组(B)24只,人参皂苷治疗组(C)24只。于造模2、7、14、28d后,用Real time RT-PCR和Western blot方法检测各组大鼠右侧腓肠肌MAFbx mRNA和蛋白的表达。结果:失神经组MAFbx表达在各时间点均明显高于假失神经组(P<0.01),且在失神经2d达到峰值,而缓慢下降,失神经28d基本降至正常水平;人参皂苷组与失神经组各时间点相比,MAFbx表达均明显降低(P<0.01)。结论:人参皂苷能通过减少MAFbx的表达而延缓失神经肌萎缩的发生。
文摘The present study investigated the effects of fasting and refeeding on the expression of proteasorne-related genes and their downstream targets in the skeletal muscles of chicks. Seven-day-old chicks were fasted for 24 or 48 h and then refed for 4 h. The expression levels of MAFbx and MuRF1, which function as E3 ligases in the ubiquitin-proteasome system, were investigated at the mRNA and protein levels. MAFbx and MuRF1 expression were increased by fasting and these increases were downregulated by refeeding. The expression of the target proteins of these E3 ligases, MyoD and M-CK, was also analyzed. The levels of these proteins were downregulated by fasting, and these decreases were rescued by refeeding. The results of this study indicate that fasting stimulates MAFbx and MuRF1 expression in chicks, possibly leading to increased degradation of their corresponding target proteins.
