Table of Contents Author Guidelines Submit a Manuscript
BioMed Research International
Volume 2014 (2014), Article ID 735106, 13 pages
http://dx.doi.org/10.1155/2014/735106
Research Article

Silencing of Plasma Membrane Ca2+-ATPase Isoforms 2 and 3 Impairs Energy Metabolism in Differentiating PC12 Cells

1Department of Molecular Neurochemistry, Medical University, Mazowiecka 6/8 Street, 92215 Lodz, Poland
2Department of Molecular Biology and Genetics, Science Park, Aarhus University, Gustav Wieds Vej, No. 10, 8000 Aarhus C, Denmark
3Department of Molecular Cell Mechanisms, Medical University, Mazowiecka 6/8 Street, 92-215 Lodz, Poland

Received 1 June 2014; Accepted 29 July 2014; Published 7 September 2014

Academic Editor: Namasivayam Elangovan

Copyright © 2014 Tomasz Boczek 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

A close link between Ca2+, ATP level, and neurogenesis is apparent; however, the molecular mechanisms of this relationship have not been completely elucidated. Transient elevations of cytosolic Ca2+ may boost ATP synthesis, but ATP is also consumed by ion pumps to maintain a low Ca2+ in cytosol. In differentiation process plasma membrane Ca2+ ATPase (PMCA) is considered as one of the major players for Ca2+ homeostasis. From four PMCA isoforms, the fastest PMCA2 and PMCA3 are expressed predominantly in excitable cells. In the present study we assessed whether PMCA isoform composition may affect energy balance in differentiating PC12 cells. We found that PMCA2-downregulated cells showed higher basal O2 consumption, lower NAD(P)H level, and increased activity of ETC. These changes associated with higher resulted in elevated ATP level. Since PMCA2-reduced cells demonstrated greatest sensitivity to ETC inhibition, we suppose that the main source of energy for PMCA isoforms 1, 3, and 4 was oxidative phosphorylation. Contrary, cells with unchanged PMCA2 expression exhibited prevalence of glycolysis in ATP generation. Our results with PMCA2- or PMCA3-downregulated lines provide an evidence of a novel role of PMCA isoforms in regulation of bioenergetic pathways, and mitochondrial activity and maintenance of ATP level during PC12 cells differentiation.