While hypoxic signaling has been shown to play a role in many cellular processes,its role in metabolism-linked extracellular matrix(ECM)organization and downstream processes of cell fate after musculoskeletal injury r...While hypoxic signaling has been shown to play a role in many cellular processes,its role in metabolism-linked extracellular matrix(ECM)organization and downstream processes of cell fate after musculoskeletal injury remains to be determined.Heterotopicossification(HO)is a debilitating condition where abnormal bone formation occurs within extra-skeletal tissues.Hypoxia andhypoxia-inducible factor 1α(HIF-1α)activation have been shown to promote HO.However,the underlying molecular mechanisms bywhich the HIF-1αpathway in mesenchymal progenitor cells(MPCs)contributes to pathologic bone formation remain to beelucidated.Here,we used a proven mouse injury-induced HO model to investigate the role of HIF-1αon aberrant cell fate.Usingsingle-cell RNA sequencing(scRNA-seq)and spatial transcriptomics analyses of the HO site,we found that collagen ECM organizationis the most highly up-regulated biological process in MPCs.Zeugopod mesenchymal cell-specific deletion of Hif1α(Hoxa11-CreER^(T2);Hif1a^(fl/fl))significantly mitigated HO in vivo.ScRNA-seq analysis of these Hoxa11-CreER^(T2);Hif1a^(fl/fl)mice identified the PLOD2/LOXpathway for collagen cross-linking as downstream of the HIF-1αregulation of HO.Importantly,our scRNA-seq data and mechanisticstudies further uncovered that glucose metabolism in MPCs is most highly impacted by HIF-1αdeletion.From a translational aspect,a pan-LOX inhibitor significantly decreased HO.A newly screened compound revealed that the inhibition of PLOD2 activity in MPCssignificantly decreased osteogenic differentiation and glycolytic metabolism.This suggests that the HIF-1α/PLOD2/LOX axis linked tometabolism regulates HO-forming MPC fate.These results suggest that the HIF-1α/PLOD2/LOX pathway represents a promisingstrategy to mitigate HO formation.展开更多
文摘While hypoxic signaling has been shown to play a role in many cellular processes,its role in metabolism-linked extracellular matrix(ECM)organization and downstream processes of cell fate after musculoskeletal injury remains to be determined.Heterotopicossification(HO)is a debilitating condition where abnormal bone formation occurs within extra-skeletal tissues.Hypoxia andhypoxia-inducible factor 1α(HIF-1α)activation have been shown to promote HO.However,the underlying molecular mechanisms bywhich the HIF-1αpathway in mesenchymal progenitor cells(MPCs)contributes to pathologic bone formation remain to beelucidated.Here,we used a proven mouse injury-induced HO model to investigate the role of HIF-1αon aberrant cell fate.Usingsingle-cell RNA sequencing(scRNA-seq)and spatial transcriptomics analyses of the HO site,we found that collagen ECM organizationis the most highly up-regulated biological process in MPCs.Zeugopod mesenchymal cell-specific deletion of Hif1α(Hoxa11-CreER^(T2);Hif1a^(fl/fl))significantly mitigated HO in vivo.ScRNA-seq analysis of these Hoxa11-CreER^(T2);Hif1a^(fl/fl)mice identified the PLOD2/LOXpathway for collagen cross-linking as downstream of the HIF-1αregulation of HO.Importantly,our scRNA-seq data and mechanisticstudies further uncovered that glucose metabolism in MPCs is most highly impacted by HIF-1αdeletion.From a translational aspect,a pan-LOX inhibitor significantly decreased HO.A newly screened compound revealed that the inhibition of PLOD2 activity in MPCssignificantly decreased osteogenic differentiation and glycolytic metabolism.This suggests that the HIF-1α/PLOD2/LOX axis linked tometabolism regulates HO-forming MPC fate.These results suggest that the HIF-1α/PLOD2/LOX pathway represents a promisingstrategy to mitigate HO formation.
