The effect of denervation on protein synthesis and degradation in adult rat diaphragm muscle
The effect of denervation on protein synthesis and degradation in adult rat diaphragm muscle
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DOI：
10.1152/japplphysiol.91247.2008
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发表时间：
2009-08-01
影响因子：
3.3
通讯作者：
Sieck, Gary C.
中科院分区：
文献类型：
--
作者：
Argadine, Heather M.;Hellyer, Nathan J.;Sieck, Gary C.
Argadine HM，Hellyer NJ，Mantilla CB，Zhan WZ，Sieck GC.失神经支配对成年大鼠膈肌蛋白质合成与降解的影响。J Appl Physiol 107：438-444，2009.首次发表于2009年6月11日; doi：10.1152/japplphysiol.91247.2008。先前的研究表明，大鼠膈肌（DIAm）单侧去神经（DNV）导致DNV后1天肌球蛋白重链蛋白丢失。我们推测DNV通过激活泛素-蛋白酶体途径降低了蛋白质的净平衡。在DIAm条中，通过掺入H-3-Tyr来测量蛋白质合成，并且通过DNV后1、3、5、7和14天的Tyr释放来测量蛋白质降解。总蛋白泛素化，caspase-3的表达/活性，和肌动蛋白片段进行了分析Western分析。我们发现，在DNV后3天，蛋白质合成相对于假手术对照增加了77%。蛋白质合成在DNV后第5天（85%）、第7天（53%）和第14天（123%）保持升高。在DNV后5天，蛋白质降解相对于假手术对照增加了43%，并在DNV后7天（49%）和14天（74%）保持升高。因此，在DNV后5天，与假手术对照组相比，净蛋白平衡降低了43%，并且在DNV后7天（49%）和14天（72%）与假手术组相比降低。蛋白质泛素化在DNV后5天增加并保持升高。DNV对caspase-3活性或肌动蛋白片段化没有影响，表明泛素-蛋白酶体途径而不是caspase-3活化在DIAm对DNV的反应中是重要的。收缩性蛋白质（如肌球蛋白重链）的早期丢失可能是选择性蛋白质降解的结果，而不是一般性蛋白质分解的结果。未来的研究应该评估DNV的这种选择性作用。
Argadine HM, Hellyer NJ, Mantilla CB, Zhan WZ, Sieck GC. The effect of denervation on protein synthesis and degradation in adult rat diaphragm muscle. J Appl Physiol 107: 438-444, 2009. First published June 11, 2009; doi:10.1152/japplphysiol.91247.2008.-Previous studies showed that unilateral denervation (DNV) of the rat diaphragm muscle (DIAm) results in loss of myosin heavy chain protein by 1 day after DNV. We hypothesize that DNV decreases net protein balance as a result of activation of the ubiquitin-proteasome pathway. In DIAm strips, protein synthesis was measured by incorporation of H-3-Tyr, and protein degradation was measured by Tyr release at 1, 3, 5, 7, and 14 days after DNV. Total protein ubiquitination, caspase-3 expression/activity, and actin fragmentation were analyzed by Western analysis. We found that, at 3 days after DNV, protein synthesis increased by 77% relative to sham controls. Protein synthesis remained elevated at 5 (85%), 7 (53%), and 14 days (123%) after DNV. At 5 days after DNV, protein degradation increased by 43% relative to sham controls and remained elevated at 7 (49%) and 14 days (74%) after DNV. Thus, by 5 days after DNV, net protein balance decreased by 43% compared with sham controls and was decreased compared with sham at 7 (49%) and 14 days (72%) after DNV. Protein ubiquitination increased at 5 days after DNV and remained elevated. DNV had no effect on caspase-3 activity or actin fragmentation, suggesting that the ubiquitin-proteasome pathway rather than caspase-3 activation is important in the DIAm response to DNV. Early loss of contractile proteins, such as myosin heavy chain, is likely the result of selective protein degradation rather than generalized protein breakdown. Future studies should evaluate this selective effect of DNV.