Mitochondrial mechanism of neuroprotection by CART.
We previously demonstrated that the neuropeptide cocaine- and amphetamine-regulated transcript (CART) is protective against focal cerebral ischemia in vivo and against neuronal cell death in culture induced by oxygen-glucose deprivation (OGD). The mechanism of neuroprotection by CART is unknown, in part due to lack of knowledge regarding its putative receptor. Using a yeast two-hybrid system with CART's carboxy-terminal to screen a mouse brain cDNA library, we uncovered a potential direct interaction between CART and subunit B of the mitochondrial enzyme succinate dehydrogenase (SDHB). We confirmed CART/SDHB binding using in vitro pull-down assay, and tested the effects of CART peptide on SDH activity, Complex II (CII) activity and ATP production in primary cultured cortical neurons under basal conditions and after OGD. At concentrations between 0.2 and 4 nM, CART significantly increased SDH function, CII activity and ATP generation in purified mitochondria and intact neurons under baseline conditions. Furthermore, pretreatment with CART enhanced mitochondrial mechanisms of neuronal survival and prevented the decline in SDH and CII activities and ATP production after OGD. The findings suggest that CART's neuroprotective mechanism of action may be linked to preservation of mitochondrial function and prevention of energy failure after ischemia-reperfusion injury.
Mao
Peizhong
P
Department of Public Health & Preventive Medicine, Oregon Health & Science University, Portland, OR 97239-3098, USA.
Ardeshiri
Ardi
A
Jacks
Rachel
R
Yang
Sufang
S
Hurn
Patricia D
PD
Alkayed
Nabil J
NJ
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology*; D042963:Electron Transport Complex II / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism* / Q000503:physiopathology; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D015427:Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology; D013385:Succinate Dehydrogenase / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
D007506:Iron-Sulfur Proteins; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; D000255:Adenosine Triphosphate; D042963:Electron Transport Complex II; C108095:SDHB protein, human; D013385:Succinate Dehydrogenase