MSCs-derived apoptotic extracellular vesicles promote muscle regeneration by inducing Pannexin 1 channel-dependent creatine release by myoblasts / 国际口腔科学杂志·英文版

Severe muscle injury is hard to heal and always results in a poor prognosis. Recent studies found that extracellular vesicle-based therapy has promising prospects for regeneration medicine, however, whether extracellular vesicles have therapeutic effects on severe muscle injury is still unknown. Herein, we extracted apoptotic extracellular vesicles derived from mesenchymal stem cells (MSCs-ApoEVs) to treat cardiotoxin induced tibialis anterior (TA) injury and found that MSCs-ApoEVs promoted muscles regeneration and increased the proportion of multinucleated cells. Besides that, we also found that apoptosis was synchronized during myoblasts fusion and MSCs-ApoEVs promoted the apoptosis ratio as well as the fusion index of myoblasts. Furthermore, we revealed that MSCs-ApoEVs increased the relative level of creatine during myoblasts fusion, which was released via activated Pannexin 1 channel. Moreover, we also found that activated Pannexin 1 channel was highly expressed on the membrane of myoblasts-derived ApoEVs (Myo-ApoEVs) instead of apoptotic myoblasts, and creatine was the pivotal metabolite involved in myoblasts fusion. Collectively, our findings firstly revealed that MSCs-ApoEVs can promote muscle regeneration and elucidated that the new function of ApoEVs as passing inter-cell messages through releasing metabolites from activated Pannexin 1 channel, which will provide new evidence for extracellular vesicles-based therapy as well as improving the understanding of new functions of extracellular vesicles.

Research advances in characteristics of biotransport and biotransformation and toxicities of quantum dots in vivo / 中国药理学与毒理学杂志

As a novel fluorescent nanomaterial,quantum dots (QDs) have a prospect for wide application. However , the adverse effects of QDs have become a concern among and more researchers. The toxic actions of QDs in vivo are closely associated with the biotransport and bio?transformation of QDs,which can be affected by the exposure pathways,exposure dose,surface modification and the particle size. Among them,the exposure pathways can affect the absorption and distribution of QDs in vivo,the exposure dose can affect the metabolism and excretion,thus influencing the distribution of QDs in vivo ,the surface modification can affect the distribution ,metabolism and excretion of QDs in vivo,the particle size can affect the absorption,distribution and excretion of QDs in vivo,and larger QDs are more likely to remain in the body and difficult to remove. QDs can enter the body through the circulatory system,get accumulated and degraded in the liver,kidney and other organs. The degraded products can be excerted through excrement and urine under the metabolism in the liver,spleen and kidneys. In addition,QDs can interact with biological macromolecules in the body,causing DNA damage,affecting the function and gene expression level of the liver,kidney,nervous system and other organs,and resulting in pathological and functional damage to tissues and organs.