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Journal of Toxicology
Volume 2014 (2014), Article ID 194967, 8 pages
http://dx.doi.org/10.1155/2014/194967
Research Article

Conditioned Medium Reconditions Hippocampal Neurons against Kainic Acid Induced Excitotoxicity: An In Vitro Study

1School of Regenerative Medicine, Manipal University, GKVK Post, Bellary Road, Allalasandra, Near Hotel Royal Orchid, Yelahanka, Bangalore 560065, India
2Department of Neurophysiology, National Institute of Mental Health and Neurosciences, Deemed University, Hosur Road, Bangalore 560029, India

Received 22 July 2014; Revised 20 October 2014; Accepted 27 October 2014; Published 23 November 2014

Academic Editor: Maria Teresa Colomina

Copyright © 2014 Pradeep Kumar K. Bevinahal 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

Stem cell therapy is gaining attention as a promising treatment option for neurodegenerative diseases. The functional efficacy of grafted cells is a matter of debate and the recent consensus is that the cellular and functional recoveries might be due to “by-stander” effects of grafted cells. In the present study, we investigated the neuroprotective effect of conditioned medium (CM) derived from human embryonic kidney (HEK) cells in a kainic acid (KA) induced hippocampal degeneration model system in in vitro condition. Hippocampal cell line was exposed to KA (200 µM) for 24 hrs (lesion group) whereas, in the treatment group, hippocampal cell line was exposed to KA in combination with HEK-CM (KA + HEK-CM). We observed that KA exposure to cells resulted in significant neuronal loss. Interestingly, HEK-CM cotreatment completely attenuated the excitotoxic effects of KA. In HEK-CM cotreatment group, the cell viability was ~85–95% as opposed to 47% in KA alone group. Further investigation demonstrated that treatment with HEK-CM stimulated the endogenous cell survival factors like brain derived neurotrophic factors (BDNF) and antiapoptotic factor Bcl-2, revealing the possible mechanism of neuroprotection. Our results suggest that HEK-CM protects hippocampal neurons against excitotoxicity by stimulating the host’s endogenous cell survival mechanisms.