Engagement of ubiquitination and de-ubiquitination at rostral ventrolateral medulla in experimental brain death
| Autor: | Julie Y.H. Chan, Carol H. Y. Wu, Samuel H.H. Chan, Alice Y.W. Chang, Jimmy L. J. Chou |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Lipopolysaccharides
Male medicine.medical_specialty Brain Death Proteasome Endopeptidase Complex Endocrinology Diabetes and Metabolism Clinical Biochemistry Lactacystin lcsh:Medicine Biology Pharmacology Proteomics Rats Sprague-Dawley chemistry.chemical_compound Western blot Ubiquitin Internal medicine medicine Animals Pharmacology (medical) RNA Messenger Molecular Biology Microinjection Biochemistry medical Medulla Oblongata medicine.diagnostic_test Research Biochemistry (medical) lcsh:R Ubiquitination Cell Biology General Medicine Rostral ventrolateral medulla Rats Endocrinology Proteasome chemistry Proteasome inhibitor biology.protein Ubiquitin Thiolesterase medicine.drug |
| Zdroj: | Journal of Biomedical Science Journal of Biomedical Science, Vol 19, Iss 1, p 48 (2012) |
| ISSN: | 1423-0127 1021-7770 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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