title: B-type natriuretic peptide enhances mild hypoxia-induced apoptotic cell death in cardiomyocytes.
abstract: In the case of left ventricle remodeling after myocardial infarction, cardiomyocyte apoptosis is attributed to increased cardiac workload by the stimulus such as chronic hypoxia. B-Type natriuretic peptide, being known as a reliable prognostic of cardiovascular pathology, plays an important role in the myocardial infarction. However, the action of B-type natriuretic peptide on cardiomyocytes undergoing apoptosis is unclear. In the present study, B-type natriuretic peptide have exhibited the enhancive effects on the mild hypoxia-induced cardiomyocyte apoptosis with the manifestation of facilitating phosphatidylserine evagination and increasing typical fragmented nuclei. In addition, B-type natriuretic peptide aggravated the dissipation of delta psi(m), the depletion of intracellular ATP and the increase of caspase-3 activity. 8-Bromo-cGMP, which increased cGMP independent of B-type natriuretic peptide, could mimic B-type natriuretic peptide's effects; whereas cGMP-dependent protein kinase inhibitor, Rp-8-br-cGMP inhibited that. Further study revealed the enhancive effect of BNP on down-regulation of Bcl-2 mRNA expression in the presence of mild hypoxia. In conclusion, the present study demonstrated that B-type natriuretic peptide aggravated the cardiomyocyte apoptosis by influencing hypoxia-induced mitochondrial death pathway, which is true at least in this oxygen deprivation model; and this effect was partially realized through intracellular cGMP.
authors.affiliation: Department of Biomedical Engineering, Zhejiang University (Yuquan Campus), Hangzhou, PR China.
authors.forename: Tian-Nan
authors.initials: TN
authors.lastname: Wang
authors.forename: Ya-Kun
authors.initials: YK
authors.lastname: Ge
authors.forename: Jie-Yue
authors.initials: JY
authors.lastname: Li
authors.forename: Xiang-Hui
authors.initials: XH
authors.lastname: Zeng
authors.forename: Xiao-Xiang
authors.initials: XX
authors.lastname: Zheng
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects*; D016923:Cell Death / Q000187:drug effects; D015687:Cell Hypoxia / Q000187:drug effects; D002478:Cells, Cultured; D032383:Myocytes, Cardiac / Q000187:drug effects*; D020097:Natriuretic Peptide, Brain / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D020097:Natriuretic Peptide, Brain