Butyric acid induces spontaneous adipocyte differentiation of porcine bone marrow-derived mesenchymal stem cells

Butyric acid (BA) affects the differentiation of mesenchymal stem cells (MSC) through the activation of different transcriptional pathways. The aim of this study was to determine the effects of BA on proliferation and spontaneous differentiation of porcine bone marrow-derived MSC. Second passage MSC (n = 6) were cultured in either a basal medium (BM, DMEM + 10% FBS), or BM + 2.5 mmol/L BA (BA-2.5) or BM + 5 mmol/L BA (BA-5). Cell proliferation was significantly decreased by both BA-2.5 and BA-5 after 48 h and 72 h (- 55% and - 63%, respectively). To assess the impact of BA on spontaneous differentiation, MSC were cultured for 27 d, with complete media changes every 3 d. At day 27, cells were stained for osteocytic, chondrocytic, and adipocytic differentiation. No terminal differentiation was detected in control MSC, while accumulated small drops of lipids were stained by Oil-Red-O in BA-treated cells. The phenotypic changes were associated with changes in gene expression, determined by qPCR. Treatment with BA modulated the expression of adipocytic differentiationmarkers: peroxisome proliferator-activated receptor γ and CCAAT/enhancer binding protein α were significantly increased by both BA-2.5 and BA-5 throughout the study, while lipoprotein lipase and fatty acid-binding protein 4 were increased by BA-5 at day 3, and decreased by both BA-5 and BA-2.5 later throughout the study. Osteocalcin and aggrecan mRNA was reduced throughout the experiment by both doses of BA (P < 0.05). In conclusion, our data support that BA promotes the spontaneous differentiation of porcine bone marrow-derived MSC toward an adipocytic lineage in the absence of inducing cocktail media.

Benedetta Tugnoli, Chiara Bernardini, Monica Forni, Andrea Piva, Chad H. Stahl, Ester Grilli. Butyric acid induces spontaneous adipocyte differentiation of porcine bone marrow-derived mesenchymal stem cells.In Vitro Cellular & Developmental Biology-Animal, 55:17-24, 2019.

Association of Gpx1 fluctuation in cell cycle progression

This research demonstrates fluctuation of glutathione peroxidase1 (Gpx1) throughout cell cycle progression with significant decreased expression at mitosis of HeLa cell. This was achieved with western blot (WB) analysis of target proteins from each phase of synchronized cells. The synchronizations were performed with double thymidine (T/T) for G1/S arrest and thymidine followed by nocodazole (T/N) for G2/M arrest. The G1/S arrested cells were released in fresh medium for 3, 6, 9, 10, and 15h to obtain cell at each phase such as gap1 (G1), synthesis (S), gap2 (G2), mitosis (M), and gap1 (G1) phase, respectively, for investigating Gpx1 expression throughout a complete cycle. The synchronizations were confirmed using fluorescence activated cell sorting (FACS) and WB analysis of phase-specific markers. The fluctuations of Gpx1 expression were verified with universal protein actin and peroxiredoxin1 (Prx1) which are stable throughout the cellcycle. Intriguingly, immunoblots showed the level of Gpx1 decreases at mitosis phase and increased during mitotic exit to G1 phase in HeLa cells, while Prx1 protein level remained constant. The fractionation experiments reveal that only the cytosolic Gpx1 was decreased while their levels at mitochondria remain constant. The highest levels of mitochondrial ROS were measured in mitosis phase with FACS analysis using Mito sox indicating that antioxidant activity of Gpx1 for detoxifying excessive induced endogenous reactive oxygen species (ROS) in the mitosis phase could be the reason for such decreasing level. For unfolding the molecular mechanism of such decreased expression, the Gpx1 was investigated at transcriptional, translational, and proteosomal level. The results revealed that translational mechanism is involve in the decreased expression rather than transcriptional or proteosomal degradation at mitosis phase. This finding supports that Gpx1 is involved in the cell cycle progression through regulation of endogenous ROS. Based on this observation, further research could uncover their possible association with the infinitive division of a cancer cell.

Khudishta Aktar, Abdul Kafi, Ravinder Dahiya. Association of Gpx1 fluctuation in cell cycle progression. In Vitro Cellular & Developmental Biology-Animal, 55:94-103, 2019.