Wang Z, Han X, Cui M, Fang K, Lu Z, Dong Q. Tissue kallikrein protects rat hippocampal CA1 neurons against cerebral ischemia/reperfusion-induced injury through the B2R-Raf-MEK1/2-ERK1/2 pathway.
J Neurosci Res 2014;
92:651-7. [PMID:
24464837 DOI:
10.1002/jnr.23325]
[Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/10/2013] [Accepted: 10/19/2013] [Indexed: 12/15/2022]
Abstract
We have documented that tissue kallikrein (TK) prevents neurons from hypoxia/reoxygenation injury through the B2R-ERK1/2 pathway and the antihypoxic function of TK through Homer1b/c-ERK1/2 signaling pathways. The present study investigates the molecular mechanisms of exogenous TK activation of the B2R-ERK1/2 pathway through the β-arrestin-2 assembled B2R-Raf-MEK1/2 signaling module in vivo. The cresyl violet staining results indicated that exogenous TK protected the rat hippocampal CA1 neurons against cerebral ischemia/reperfusion (I/R) injury. The immunoprecipitation (IP) and immunoblotting (IB) results revealed that exogenous TK upregulated the β-arrestin-2 assembled B2R-Raf-MEK1/2 signaling module and upregulated the phosphorylation of Raf (p-Raf), MEK1/2 (p-MEK1/2), and ERK1/2 (p-ERK1/2). Meanwhile, exogenous TK upregulated the expression of nuclear factor-κB (NF-κB), depressed the release of cytochrome c (Cyt c) and bax from mitochondria to the cytosol, and depressed the activation of caspase-3. Take together, our results suggest that exogenous TK attenuated the cerebral I/R induced rat hippocampal CA1 neurons injury through activating the β-arrestin-2 assembled B2R-Raf-MEK1/2 signaling module and that the activated B2R-Raf-MEK1/2 signaling module could upregulate the expression of NF-κB, decrease the release of cytochrome c and bax from mitochondria to the cytosol, and depress the activation of caspase-3.
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