Pannexins in the musculoskeletal system:new targets for development and disease progression

During cell differentiation,growth,and development,cells can respond to extracellular stimuli through communication channels.Pannexin(Panx)family and connexin(Cx)family are two important types of channel-forming proteins.Panx family contains three members(Panx1-3)and is expressed widely in bone,cartilage and muscle.Although there is no sequence homology between Panx family and Cx family,they exhibit similar configurations and functions.Similar to Cxs,the key roles of Panxs in the maintenance of physiological functions of the musculoskeletal system and disease progression were gradually revealed later.Here,we seek to elucidate the structure of Panxs and their roles in regulating processes such as osteogenesis,chondrogenesis,and muscle growth.We also focus on the comparison between Cx and Panx.As a new key target,Panxs expression imbalance and dysfunction in muscle and the therapeutic potentials of Panxs in joint diseases are also discussed.

Progress in osteoarthritis research by the National Natural Science Foundation of China

Osteoarthritis(OA) in China is gradually becoming an important scientific research area that has had a significant impact on research and development(R&D) activities in the OA field worldwide. This article summarizes the R&D progress related to OA in China in recent years. The National Natural Science Foundation of China(NSFC) is a national funding institution for basic research and plays a critical role in promoting and supporting Chinese scholars’ R&D activities. We collected and analyzed information on NSFC funding in the field of OA from 2010 to 2019, including the amount, the level and the program categories of the funded projects. The data fully demonstrate the important and positive role of the NSFC in supporting free exploration, cultivating research teams and young talent, and boosting OA R&D. In this article, we outline and discuss hot topics in focused areas, key advances in this field and the prospects for progress in OA research in China.

Role of adipokines in sarcopenia

Sarcopenia is an age-related disease that mainly involves decreases in muscle mass,muscle strength and muscle function.At the same time,the body fat content increases with aging,especially the visceral fat content.Adipose tissue is an endocrine organ that secretes biologically active factors called adipokines,which act on local and distant tissues.Studies have revealed that some adipokines exert regulatory effects on muscle,such as higher serum leptin levels causing a decrease in muscle function and adiponectin inhibits the transcriptional activity of Forkhead box O3(FoxO3)by activating peroxisome proliferators-activated receptor-γcoactivator-1α(PGC-1α)and sensitizing cells to insulin,thereby repressing atrophy-related genes(atrogin-1 and muscle RING finger 1[MuRF1])to prevent the loss of muscle mass.Here,we describe the effects on muscle of adipokines produced by adipose tissue,such as leptin,adiponectin,resistin,mucin and lipocalin-2,and discuss the importance of these adipokines for understanding the development of sarcopenia.