Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes

I. Golic, K. Velickovic, M. Markelic, A. Stancic, A. Jankovic, M. Vucetic, V. Otasevic, B. Buzadzic, B. Korac and A. Korac
European Journal of Histochemistry, 58 (2014), 251-257.

Abstract. Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control) drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1) and mitofusin 2 (MFN2) were increased, and mitochondrial fission as dynamin related protein 1 (DRP1) was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER). The level of uncoupling protein-1 (UCP1) was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes.

Keywords: brown adipocyte, mitochondrial dynamics, calcium, endoplasmic reticulum

IF: 2.042
IF5: 1.687
MNTR classification: M23

BibTeX:

@article{golic2014-ejh,
	author = {I. Golic and K. Velickovic and M. Markelic and A. Stancic and A. Jankovic and M. Vucetic and V. Otasevic and B. Buzadzic and B. Korac and A. Korac},
	title = {Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes},
	journal = {European Journal of Histochemistry},
	volume = {58},
	number = {3},
	year = {2014},
	url = {http://ejh.it/index.php/ejh/article/view/2377}
}