TY - JOUR AU - Golic, I. AU - Velickovic, K. AU - Markelic, M. AU - Stancic, A. AU - Jankovic, A. AU - Vucetic, M. AU - Otasevic, V. AU - Buzadzic, B. AU - Korac, B. AU - Korac, A. PY - 2014/09/09 Y2 - 2024/03/29 TI - Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes JF - European Journal of Histochemistry JA - Eur J Histochem VL - 58 IS - 3 SE - Original Papers DO - 10.4081/ejh.2014.2377 UR - https://www.ejh.it/ejh/article/view/2377 SP - AB - <p>Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca<sup>2+</sup>]<sub>i</sub> homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ<sup>® </sup>treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ<sup>®</sup> drinking or tap water (control) drinking for three days. Alizarin Red S staining showed increased Ca<sup>2+</sup> 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<sup>®</sup> decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and <em>fusioned-like</em> mitochondria in the Ca-SANDOZ<sup>®</sup> treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca<sup>2+</sup> 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<sup>®</sup> stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes</p> ER -