Background:Lumbar disc degeneration(LDD)displays considerable heterogeneity in terms of clinical features and pathological changes.However,researchers have not clearly determined whether the transcriptome variations i...Background:Lumbar disc degeneration(LDD)displays considerable heterogeneity in terms of clinical features and pathological changes.However,researchers have not clearly determined whether the transcriptome variations in LDD could be used to identify or interpret the causes of heterogeneity in clinical features.This study aimed to identify the transcriptomic classification of degenerated discs in LDD patients and whether the molecular subtypes of LDD could be accurately predicted using clinical features.Methods:One hundred and twenty-two nucleus pulposus(NP)tissues from 108 patients were consecutively collected for bulk RNA sequencing(RNA-seq).An unsupervised clustering method was employed to analyze the bulk RNA matrix.Differential analysis was performed to characterize the transcriptional signatures and subtype-specific extracellular matrix(ECM)dysregulation.The cell subpopulation states of each subtype were inferred by integrating bulk and single-cell sequencing datasets.Transwell and dual-luciferase reporter gene assays were employed to investigate possible molecular mechanisms involved.Machine learning algorithm diagnostic prediction models were developed to correlate molecular classification with clinical features.Results:LDD was classified into 4 subtypes with distinct molecular signatures and ECM remodeling:C1 with collagenesis,C2 with ossification,C3 with low chondrogenesis,and C4 with fibrogenesis.Chond1-3 in C1 dominated disc collagenesis via the activation of the mechanosensors TRPV4 and PIEZO1;NP progenitor cells in C2 exhibited chondrogenic and osteogenic phenotypes;Chond1 in C3 was linked to a disrupted hypoxic microenvironment leading to reduced chondrogenesis;Macrophages in C4 played a crucial role in disc fibrogenesis via the secretion of tumor necrosis factor-α(TNF-α).Furthermore,the random forest diagnostic prediction model was proven to have a robust performance[area under the receiver operating characteristic(ROC)curve:0.9312;accuracy:0.84]in stratifying the molecular subtypes of LDD based on 12 clinical features.Conclusions:Our study delineates 4 distinct molecular subtypes of LDD that can be accurately stratified on the basis of clinical features.The identification of these subtypes would facilitate precise diagnostics and guide the development of personalized treatment strategies for LDD.展开更多
The functional heterogeneity of hematopoietic stem cells(HSCs) has been comprehensively investigated by single-cell transplantation assay.However,the heterogeneity regarding their physiological contribution remains an...The functional heterogeneity of hematopoietic stem cells(HSCs) has been comprehensively investigated by single-cell transplantation assay.However,the heterogeneity regarding their physiological contribution remains an open question,especially for those with life-long hematopoietic fate of rigorous selfrenewing and balanced differentiation capacities.In this study,we revealed that Procr expression was detected principally in phenotypical vascular endothelium co-expressing DII4 and CD44 in the midgestation mouse embryos,and could enrich all the HSCs of the embryonic day 11.5(E11.5) aortagonad-mesonephros(AGM) region.We then used a temporally restricted genetic tracing strategy to irreversibly label the Procr-exp res sing cells at E9.5.Interestingly,most labeled mature HSCs in multiple sites(such as AGM) around E11.5 were functionally categorized as lymphomyeloid-balanced HSCs assessed by direct transplantation.Furthermore,the labeled cells contributed to an average of 7.8% of immunophenotypically defined HSCs in E14.5 fetal liver(FL) and 6.9% of leukocytes in peripheral blood(PB) during one-year follow-up.Surprisingly,in aged mice of 24 months,the embryonically tagged cells displayed constant contribution to leukocytes with no bias to myeloid or lymphoid lineages.Altogether,we demonstrated,for the first time,the existence of a subtype of physiologically long-lived balanced HSCs as hypothesized,whose precise embryonic origin and molecular identity await further characterization.展开更多
基金supported by the National Natural Science Foundation of China(32270887,82272507,32200654,82430079,and 82472519)the National Key Research and Development Program of China(2022YFA1103202)+7 种基金the Chongqing High-End Medical Talents for Middle-aged and Young(YXGD202408)the Army Scientific and Technological Innovation Talents Prioritized Suppor t Program(2023-124)the Natural Science Foundation of Chongqing(CSTB2023NSCQ-ZDJO008)the Postdoctoral Innovative Talent Support Program(BX20220397)the Open Project of State Key Laboratory of TraumaBurns and Combined Injury(SFLKF202201)the Project for Enhancing Innovation of Army Medical University(2023XJS39)the Talent Innovation Training Program at the Army Medical Center(ZXZYTSYS09)。
文摘Background:Lumbar disc degeneration(LDD)displays considerable heterogeneity in terms of clinical features and pathological changes.However,researchers have not clearly determined whether the transcriptome variations in LDD could be used to identify or interpret the causes of heterogeneity in clinical features.This study aimed to identify the transcriptomic classification of degenerated discs in LDD patients and whether the molecular subtypes of LDD could be accurately predicted using clinical features.Methods:One hundred and twenty-two nucleus pulposus(NP)tissues from 108 patients were consecutively collected for bulk RNA sequencing(RNA-seq).An unsupervised clustering method was employed to analyze the bulk RNA matrix.Differential analysis was performed to characterize the transcriptional signatures and subtype-specific extracellular matrix(ECM)dysregulation.The cell subpopulation states of each subtype were inferred by integrating bulk and single-cell sequencing datasets.Transwell and dual-luciferase reporter gene assays were employed to investigate possible molecular mechanisms involved.Machine learning algorithm diagnostic prediction models were developed to correlate molecular classification with clinical features.Results:LDD was classified into 4 subtypes with distinct molecular signatures and ECM remodeling:C1 with collagenesis,C2 with ossification,C3 with low chondrogenesis,and C4 with fibrogenesis.Chond1-3 in C1 dominated disc collagenesis via the activation of the mechanosensors TRPV4 and PIEZO1;NP progenitor cells in C2 exhibited chondrogenic and osteogenic phenotypes;Chond1 in C3 was linked to a disrupted hypoxic microenvironment leading to reduced chondrogenesis;Macrophages in C4 played a crucial role in disc fibrogenesis via the secretion of tumor necrosis factor-α(TNF-α).Furthermore,the random forest diagnostic prediction model was proven to have a robust performance[area under the receiver operating characteristic(ROC)curve:0.9312;accuracy:0.84]in stratifying the molecular subtypes of LDD based on 12 clinical features.Conclusions:Our study delineates 4 distinct molecular subtypes of LDD that can be accurately stratified on the basis of clinical features.The identification of these subtypes would facilitate precise diagnostics and guide the development of personalized treatment strategies for LDD.
基金supported by grants from the National Key R&D Program of China (2017YFA0103401 and 2016YFA0100601)the National Natural Science Foundation of China(31425012,31930054,31871173 and 81890991)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2017ZT07S347)
文摘The functional heterogeneity of hematopoietic stem cells(HSCs) has been comprehensively investigated by single-cell transplantation assay.However,the heterogeneity regarding their physiological contribution remains an open question,especially for those with life-long hematopoietic fate of rigorous selfrenewing and balanced differentiation capacities.In this study,we revealed that Procr expression was detected principally in phenotypical vascular endothelium co-expressing DII4 and CD44 in the midgestation mouse embryos,and could enrich all the HSCs of the embryonic day 11.5(E11.5) aortagonad-mesonephros(AGM) region.We then used a temporally restricted genetic tracing strategy to irreversibly label the Procr-exp res sing cells at E9.5.Interestingly,most labeled mature HSCs in multiple sites(such as AGM) around E11.5 were functionally categorized as lymphomyeloid-balanced HSCs assessed by direct transplantation.Furthermore,the labeled cells contributed to an average of 7.8% of immunophenotypically defined HSCs in E14.5 fetal liver(FL) and 6.9% of leukocytes in peripheral blood(PB) during one-year follow-up.Surprisingly,in aged mice of 24 months,the embryonically tagged cells displayed constant contribution to leukocytes with no bias to myeloid or lymphoid lineages.Altogether,we demonstrated,for the first time,the existence of a subtype of physiologically long-lived balanced HSCs as hypothesized,whose precise embryonic origin and molecular identity await further characterization.
