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Enhanced survival of vascular smooth muscle cells accounts for heightened elastin deposition in arteries of neonatal spontaneously hypertensive rats
Author(s) -
Arribas Silvia M.,
Hermida Carmen,
González M. Carmen,
Wang Yanting,
Hinek Aleksander
Publication year - 2010
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2009.050971
Subject(s) - elastin , vascular smooth muscle , medicine , extracellular matrix , propidium iodide , endocrinology , fibronectin , apoptosis , tunel assay , programmed cell death , biology , chemistry , microbiology and biotechnology , pathology , biochemistry , smooth muscle
Abnormal stiffening and narrowing of arteries are characteristic features of spontaneously hypertensive rats (SHR). In this strain, we have previously demonstrated an increased elastin content and abnormal organization of lamellae in conduit and resistance arteries from neonatal rats that preceded the impending inward remodelling, increased vascular stiffness and development of hypertension. The aim of this study was to assess the mechanism responsible for such excessive and aberrant elastin deposition in SHR vessels during perinatal development. We compared elastin, collagen and fibronectin production (inmunocytochemistry and quantitative assay of metabolically labelled insoluble elastin), DNA content as well as cell proliferation (proliferative cellular nuclear antigen, bromodeoxyuridine incorporation) and death rates (propidium iodide exclusion test, terminal transferase nick and labeling (TUNEL) assay) in cultures of vascular smooth muscle cells (VSMC) derived from neonatal SHR and Wistar–Kyoto (WKY) control rats. Cultures of VSMC derived from neonatal SHR exhibited hypertrophy, produced more elastin, collagen and fibronectin and contained more DNA than equally plated WKY counterparts. Further analysis revealed that the higher net DNA content in SHR‐derived cultures was due to increased diploidy, but not to a heightened cell multiplication. The SHR‐derived VSMC also exhibited lower rates of cell death and apoptosis, which were associated with increased levels of the anti‐apoptotic protein, survivin. We therefore conclude that the peculiar heightened survival of matrix‐producing VSMC in neonatal SHR is responsible for accumulation of hard‐wearing elastin and other extracellular matrix elements in the growing arteries, thereby contributing to the subsequent development of systemic hypertension.