Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H ...Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.展开更多
Osteoporosis is a debilitating bone disease affecting millions of people. Here, we used human urine-derived stem cells(USCs),which were noninvasively harvested from unlimited and easily available urine, as a "fac...Osteoporosis is a debilitating bone disease affecting millions of people. Here, we used human urine-derived stem cells(USCs),which were noninvasively harvested from unlimited and easily available urine, as a "factory" to obtain extracellular vesicles(USCEVs) and demonstrated that the systemic injection of USC-EVs effectively alleviates bone loss and maintains bone strength in osteoporotic mice by enhancing osteoblastic bone formation and suppressing osteoclastic bone resorption. More importantly, the anti-osteoporotic properties of USC-EVs are not notably disrupted by the age, gender, or health condition(with or without osteoporosis) of the USC donor. Mechanistic studies determined that collagen triple-helix repeat containing 1(CTHRC1) and osteoprotegerin(OPG) proteins are enriched in USC-EVs and required for USC-EV-induced pro-osteogenic and anti-osteoclastic effects. Our results suggest that autologous USC-EVs represent a promising novel therapeutic agent for osteoporosis by promoting osteogenesis and inhibiting osteoclastogenesis by transferring CTHRC1 and OPG.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.81874006,82172399,81902222,82060395,81902277,82072504,82000845)the Hunan Province Natural Science Foundation of China (Grant Nos.2020JJ4928,2020JJ4897,2021JJ30038,2021JJ40492)the Independent Exploration and Innovation Project of Central South University (Grant Nos.2020zzts255)。
文摘Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.
基金supported by the National Natural Science Foundation of China (Grant nos. 81522012, 81702237, 81670807, 81871822, 81801395, 81600699, 81701383, and 81802138)the Thousand Youth Talents Plan of China (Grant no. D1119003)+8 种基金the Medicine and Health Science and Technology Innovation Project of Chinese Academy of Medical Sciences (Grant no. 2018-I2M-HL-024)the High Level Talent Gathering Project of Hunan Province (Grant nos. 2017XK2039, and 2018RS3029)the Innovation Driven Project of Central South University (Grant nos. 2016CX028,2019CX014, and 2018CX029)the Youth Foundation of Xiangya Hospital in Central South University (Grant no. 2016Q10)the Hunan Provincial Innovation Foundation for Postgraduate (Grant no. CX2018B045)the Fundamental Research Funds for the Central Universities of Central South University (Grant nos. 2017zzts211 and 2018zzts895)the Hunan Province Natural Science Foundation of China (Grant no. 2017JJ3501)the China Postdoctoral Science Foundation (Grant nos. 2017M612596, 2017M622614, and 2018M632998)the Natural Science Foundation for Distinguished Yong Scholars of Guangdong Province (Grant no. 2016A030306051)
文摘Osteoporosis is a debilitating bone disease affecting millions of people. Here, we used human urine-derived stem cells(USCs),which were noninvasively harvested from unlimited and easily available urine, as a "factory" to obtain extracellular vesicles(USCEVs) and demonstrated that the systemic injection of USC-EVs effectively alleviates bone loss and maintains bone strength in osteoporotic mice by enhancing osteoblastic bone formation and suppressing osteoclastic bone resorption. More importantly, the anti-osteoporotic properties of USC-EVs are not notably disrupted by the age, gender, or health condition(with or without osteoporosis) of the USC donor. Mechanistic studies determined that collagen triple-helix repeat containing 1(CTHRC1) and osteoprotegerin(OPG) proteins are enriched in USC-EVs and required for USC-EV-induced pro-osteogenic and anti-osteoclastic effects. Our results suggest that autologous USC-EVs represent a promising novel therapeutic agent for osteoporosis by promoting osteogenesis and inhibiting osteoclastogenesis by transferring CTHRC1 and OPG.
