Mediation of BMP7 neuroprotection by MAPK and PKC IN rat primary cortical cultures.
We have previously demonstrated that pretreatment with bone morphogenetic protein 7 (BMP7), a trophic factor in the TGFbeta superfamily, reduces ischemia-induced brain infarction induced by middle cerebral artery ligation in rats. Since the mitogen-activated protein kinase (MAPK) pathway is involved in many TGFbeta-mediated responses, we examined the interaction of BMP7 and MAPK in primary cultures obtained from the cerebral cortex of E16-17 rat embryos. Lactate dehydrogenase (LDH) in the media was used as an index of cell death. BMP7 did not alter LDH levels at low concentration (1.25 nM), but exhibited increased cellular toxicity at higher concentration (>12.5 nM). BMP7 at the low concentration significantly attenuated H2O2-induced increases in LDH activity and decreases in neuronal density. Pharmacological interactions were used to examine if MAPK was involved in this response. BMP7-induced protection was antagonized by the p42,44 MAPK kinase inhibitors PD98059 and U0125. The p38 MAPK antagonist SB203580, and their inactive analog SB202474, also attenuated BMP7-induced protection, suggesting that the interaction with p38 MAPK is nonspecific. Previous studies have indicated that SB202474 has inhibitory effects on other protein kinases. We found that the protein kinase C inhibitor chelerythrine antagonized BMP7-induced protection against H2O2. Western blot analysis indicated that BMP7 increased phosphorylation of p42,44 MAPK and PKC. Taken together, our data suggest that BMP7 is neuroprotective at low concentrations in primary cortical cell culture. The protective effects of BMP7 may involve the activation of p42,44 MAPK and PKC.
Cox
Suyu
S
Neural Protection and Regeneration, National Institute on Drug Abuse, NIH, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
Harvey
Brandon K
BK
Sanchez
Joseph F
JF
Wang
Jia-Yi
JY
Wang
Yun
Y
D000818:Animals; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors / Q000633:toxicity; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D016877:Oxidants / Q000037:antagonists & inhibitors / Q000633:toxicity; D010766:Phosphorylation / Q000187:drug effects; D010940:Plant Proteins; D011493:Protein Kinase C / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
C525821:Bmp7 protein, rat; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D004791:Enzyme Inhibitors; D018696:Neuroprotective Agents; D016877:Oxidants; D010940:Plant Proteins; D016212:Transforming Growth Factor beta; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D011493:Protein Kinase C; C101691:MMK4 protein, Medicago sativa; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases