Engagement of ubiquitination and de-ubiquitination at rostral ventrolateral medulla in experimental brain death

Carol H. Wu, Julie Y. Chan, Jimmy Li Jer Chou, Samuel H. Chan, Alice Y. Chang

研究成果: Article同行評審

6 引文 斯高帕斯(Scopus)


Background: Whereas brain death is a vitally important clinical phenomenon, our contemporary understanding on its underlying cellular mechanisms remains elusive. This study evaluated whether the ubiquitin-proteasome system (UPS) in the rostral ventrolateral medulla (RVLM), a neural substrate that our laboratory identified previously to be intimately related to brain death, is engaged in this fatal process. Methods: We performed proteomics, Western Blot, real-time PCR, ELISA and pharmacological experiments in conjunction with a clinically relevant experimental endotoxemia model of brain death based on intravenous administration of Escherichia coli lipopolysaccharide in adult male Sprague-Dawley rats. Results: Proteomics, Western blot and enzyme activity analyses demonstrated that polyubiquitination was preserved and de-ubiquitination by ubiquitin C-terminal hydrolase isozyme-L1 (UCH-L1) was sustained, alongside increased monoubiquitin availability or proteasome activity in RVLM over the course of experimental endotoxemia. However, real-time PCR revealed no significant alteration in proteasome subunit alpha type-1, ubiquitin or UCH-L1 at mRNA level. Functionally, whereas microinjection into the bilateral RVLM of proteasome inhibitors (lactacystin or proteasome inhibitor II) potentiated survival, an inhibitor of ubiquitin-recycling (ubiquitin aldehyde) or an UCH-L1 inhibitor exacerbated mortality. Conclusions: We proposed previously that the progression towards brain death entails a tug-of-war between pro-death and pro-life programs in RVLM. It is conceivable that ubiquitination or de-ubiquitination in RVLM participate in brain death by regulating the degradation of the proteins involved in those programs.

期刊Journal of biomedical science
出版狀態Published - 2012

All Science Journal Classification (ASJC) codes

  • 內分泌學、糖尿病和代謝
  • 分子生物學
  • 臨床生物化學
  • 細胞生物學
  • 生物化學(醫學)
  • 藥學(醫學)


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