Role of p53 and transcription-independent p53-induced apoptosis in shear-stimulated megakaryocytic maturation, particle generation, and platelet biogenesis.

Autor: Luff SA; Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America.; Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America., Kao CY; Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America.; Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, United States of America., Papoutsakis ET; Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America.; Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America.; Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2018 Sep 19; Vol. 13 (9), pp. e0203991. Date of Electronic Publication: 2018 Sep 19 (Print Publication: 2018).
DOI: 10.1371/journal.pone.0203991
Abstrakt: Megakaryocytes (Mks) derive from hematopoietic stem and progenitor cells (HSPCs) in the bone marrow and develop into large, polyploid cells that eventually give rise to platelets. As Mks mature, they migrate from the bone marrow niche into the vasculature, where they are exposed to shear forces from blood flow, releasing Mk particles (platelet-like particles (PLPs), pro/preplatelets (PPTs), and Mk microparticles (MkMPs)) into circulation. We have previously shown that transcription factor p53 is important in Mk maturation, and that physiological levels of shear promote Mk particle generation and platelet biogenesis. Here we examine the role of p53 in the Mk shear-stress response. We show that p53 is acetylated in response to shear in both immature and mature Mks, and that decreased expression of deacetylase HDAC1, and increased expression of the acetyltransferases p300 and PCAF might be responsible for these changes. We also examined the hypothesis that p53 might be involved in the shear-induced Caspase 3 activation, phosphatidylserine (PS) externalization, and increased biogenesis of PLPs, PPTs, and MkMPs. We show that p53 is involved in all these shear-induced processes. We show that in response to shear, acetyl-p53 binds Bax, cytochrome c is released from mitochondria, and Caspase 9 is activated. We also show that shear-stimulated Caspase 9 activation and Mk particle biogenesis depend on transcription-independent p53-induced apoptosis (TIPA), but PS externalization is not. This is the first report to show that shear flow stimulates TIPA and that Caspase 9 activation and Mk-particle biogenesis are directly modulated by TIPA.
Competing Interests: The authors declare that they have no conflicts of interest with the contents of this article.
Databáze: MEDLINE
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