Despite recent advances in the treatment and prevention of cardiovascular disease, stroke remains the third leading cause of death and a leading cause of serious, long-term disability in US. Therapeutic strategies aimed at minimizing the deleterious effects of ischemia on neurons once stroke takes place are still lacking, and clinical trials using neuroprotective agents have largely failed. We uncovered an endogenous mechanism of neuroprotection, whereby neurons respond to ischemia by increasing the number of peroxisomes, highly adaptable small organelles that contribute to neuronal survival by enhancing neuronal cell antioxidant capacity and the ability to cope with metabolic stress during ischemia-reperfusion. The proposed project will use both in vivo and in vitro models of ischemic neural injury to determine if peroxisomal proliferation is increased in neurons after ischemia by the translocation to peroxisomes of an otherwise cytosolic enzyme called soluble epoxide hydrolase (sEH).
Aim 1 will determine if sEH translocation requires binding of its peroxisome-targeting signal-1 (PTS-1), located on the C-terminal, to the peroxisomal shuttle protein peroxin 5 (PEX5).
Aim 2 will determine if sEH translocation contributes to peroxisomal proliferation, which plays a neuroprotective role after cerebral ischemia.
Aim 3 will determine if increased peroxisomal density after cerebral ischemia is mediated though a dual action of sEH to promote peroxisomal biogenesis and suppress peroxisomal degradation. The proposed research is highly significant and innovative both technically and conceptually. Peroxisomal biogenesis has not been previously described in brain after cerebral ischemia, and a role for sEH in this process has not been investigated. If confirmed, the proposed studies will pave the way for a new line of research focusing on peroxisomal biogenesis after stroke, and may lead to the development of novel therapeutic agents for stroke based on promoting peroxisomal translocation of sEH and enhancing the endogenous neuroprotective response to increase peroxisomal biogenesis and prevent their degradation.
The proposed research is aimed at understanding how small organelles called peroxisomes increase in number to protect neurons from stroke. The results will pave the way for the development of new therapeutic agents for stroke based on simulating and enhancing this endogenous neuronal response to injury.
|Davis, Catherine M; Liu, Xuehong; Alkayed, Nabil J (2017) Cytochrome P450 eicosanoids in cerebrovascular function and disease. Pharmacol Ther 179:31-46|
|Nelson, Jonathan W; Das, Anjali J; Barnes, Anthony P et al. (2016) Disrupting Dimerization Translocates Soluble Epoxide Hydrolase to Peroxisomes. PLoS One 11:e0152742|
|Jia, Jia; Davis, Catherine M; Zhang, Wenri et al. (2016) Sex- and isoform-specific mechanism of neuroprotection by transgenic expression of P450 epoxygenase in vascular endothelium. Exp Neurol 279:75-85|
|Siler, Dominic A; Martini, Ross P; Ward, Jonathan P et al. (2015) Protective role of p450 epoxyeicosanoids in subarachnoid hemorrhage. Neurocrit Care 22:306-19|
|Zuloaga, Kristen L; Zhang, Wenri; Yeiser, Lauren A et al. (2015) Neurobehavioral and imaging correlates of hippocampal atrophy in a mouse model of vascular cognitive impairment. Transl Stroke Res 6:390-8|
|Nelson, Jonathan W; Zhang, Wenri; Alkayed, Nabil J et al. (2015) Peroxisomal translocation of soluble epoxide hydrolase protects against ischemic stroke injury. J Cereb Blood Flow Metab 35:1416-20|
|Young, Jennifer M; Nelson, Jonathan W; Cheng, Jian et al. (2015) Peroxisomal biogenesis in ischemic brain. Antioxid Redox Signal 22:109-20|
|Zhu, W; Dotson, A L; Libal, N L et al. (2015) Recombinant T-cell receptor ligand RTL1000 limits inflammation and decreases infarct size after experimental ischemic stroke in middle-aged mice. Neuroscience 288:112-9|
|Siler, Dominic A; Berlow, Yosef A; Kukino, Ayaka et al. (2015) Soluble Epoxide Hydrolase in Hydrocephalus, Cerebral Edema, and Vascular Inflammation After Subarachnoid Hemorrhage. Stroke 46:1916-22|
|Zhu, Wenbin; Casper, Amanda; Libal, Nicole L et al. (2015) Preclinical evaluation of recombinant T cell receptor ligand RTL1000 as a therapeutic agent in ischemic stroke. Transl Stroke Res 6:60-8|
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