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BioMed Research International
Volume 2017, Article ID 3691349, 16 pages
https://doi.org/10.1155/2017/3691349
Research Article

Effects of Hyperglycemia on Vascular Smooth Muscle Ca2+ Signaling

Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Doha, Qatar

Correspondence should be addressed to Khaled Machaca; ude.llenroc.dem-rataq@2002mhk

Received 4 December 2016; Accepted 24 May 2017; Published 21 June 2017

Academic Editor: Marwan Refaat

Copyright © 2017 Nahed El-Najjar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Diabetes is a complex disease that is characterized with hyperglycemia, dyslipidemia, and insulin resistance. These pathologies are associated with significant cardiovascular implications that affect both the macro- and microvasculature. It is therefore important to understand the effects of various pathologies associated with diabetes on the vasculature. Here we directly test the effects of hyperglycemia on vascular smooth muscle (VSM) Ca2+ signaling in an isolated in vitro system using the A7r5 rat aortic cell line as a model. We find that prolonged exposure of A7r5 cells to hyperglycemia (weeks) is associated with changes to Ca2+ signaling, including most prominently an inhibition of the passive ER Ca2+ leak and the sarcoplasmic reticulum Ca2+-ATPase (SERCA). To translate these findings to the in vivo condition, we used primary VSM cells from normal and diabetic subjects and find that only the inhibition of the ER Ca2+ leaks replicates in cells from diabetic donors. These results show that prolonged hyperglycemia in isolation alters the Ca2+ signaling machinery in VSM cells. However, these alterations are not readily translatable to the whole organism situation where alterations to the Ca2+ signaling machinery are different.