Significant amount of bone mass is lost during the process of aging due to an imbalance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption in bone marrow microenvironment, which leads to net bone loss in the aging population, resulting in the pathogenesis of osteoporosis. Firstly, differences in proliferative capacity of adipocyte or adipogenic differentiation in mouse mesenchymal stem cells (MMSCs) and senile mouse model-derived bone marrow mesenchymal stem cells (SMMSCs), as well as mRNA expression of OGN and PPARγ2 were observed. Secondly, osteogenic abilities of MMSCs and SMMSCs treated with rosiglitazone (a PPARγ2 agonist) to induce osteogenic changes were observed, and negative correlation of PPARγ2 with OGN was evaluated. Thirdly, the role of SMMSCs in promoting osteogenesis was examined through enhancing expression of OGN; besides, the related mechanism was investigated by means of expression of related adipocyte and osteoblast specific genes. Forced OGN expression by OGN-infected lentivirus could increase expression of Wnt5b, RUNX2, OCN, ALP and Colla1, as well as bone formation, while decreases expression of adipogenesis marker PPARγ2. It resulted in expression inhibition of adipocyte genes such as adipocytic differentiation related genes adipocyte binding protein 2 (aP2) and osteoclast differentiation factor Rankl in bone marrow, giving rise to increased bone mass. OGN may plays a significant role in osteoporosis, which may also provide a potential target for therapeutic intervention of senile osteoporosis characterized by altered differentiation of BMSCs into osteoblasts and adipocytes.

Autophagy plays key roles in the development of acute pancreatitis (AP) and the regulation of impaired autophagy has therapeutic potential. The objective of the present study was to investigate whether pharmacological inhibition of autophagy could ameliorate AP in mice and examine the underlying mechanisms. In current study, by imaging-based high-throughput screening, a novel spautin-1 derivative spautin-A41 was identified as a potent autophagy inhibitor. Mice treated with spautin-A41 were resistant to the cerulein-induced elevation of serum pancreatic enzyme activities and pancreatic apoptosis. Mechanistically, spautin-A41 effectively reduced the expression levels of Class III phosphatidylinositol 3 (PI3) kinase complexes and subsequently ameliorated pancreatitis by inhibiting the formation of autophagosome. Therefore, pharmacological inhibition of autophagy by spautin-A41 may serve as new target for treating or lessening the severity of AP.