Pericellular Proteolysis and the Regulation of Bone/Tendon Stem Cell Fate

细胞周蛋白水解和骨/肌腱干细胞命运的调节

• 批准号: 10371563
• 负责人: STEPHEN J WEISS
• 金额: $ 43.5万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-05 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10371563
• 关键词: Anatomy; Animal Model; Bone Marrow; Caspase; Cell Lineage; Cell physiology; Cells; Chondrogenesis; Collagen; Collagen Type I; Data; Family; Genetic Transcription; Growth and Development function; In Vitro; Ligaments; Light; Link; MMP14 gene; Matrix Metalloproteinases; Membrane; Mesenchymal; Metalloproteases; Modeling; Molecular; Outcome; Pathologic; Pathway interactions; Periosteum; Phenotype; Physiologic Ossification; Physiological; Play; Population; Proteolysis; Regulation; Reporting; Role; Route; Series; Signal Pathway; Signal Transduction; Stromal Cells; Structure; Tendon structure; Tissues; Transforming Growth Factor beta; Transgenic Organisms; Trauma; Work; base; bone; carboxypeptidase C; cathepsin K; design; in vivo; intramembranous bone formation; mechanotransduction; novel; programs; proteinase In; receptor; skeletal stem cell; stem; stem cell differentiation; stem cell fate; stem cell function; stem cell population; stem cells; trafficking

ABSTRACT Bone as well as tendons each contain stem cell populations embedded in type I collagen-rich tissues. Bone marrow and endosteal-derived stem cells generate bone via endochondral ossification while periosteal stem cells form bone via the intramembranous route. In turn, tendon stem cells give rise to tenocytes that populate the mature tissues. Recent studies have identified the cysteine proteinase, cathepsin K (CTSK), as a unique marker of periosteal stem cells, a finding we have confirmed, but that also led to our identification of a heretofore uncharacterized second stem population associated with tendons. In bone marrow-derived MSCs, we have previously identified a novel requirement for the membrane-anchored metalloproteinase, MT1-MMP, in regulating a mechanosensitive, YAP/TAZ-dependent pathway that controls stem cell lineage commitment via the proteolytic remodeling of the pericellular collagen matrix. By contrast, the relative roles of MT1-MMP and CTSK in periosteal or tendon/ligament stem cells are unknown. Using a Ctsk-Cre transgenic line to target periosteal stem cells, we find that Mt1-mmp targeting alone elicits a profound osteopenic state in vivo that not only operates independently of Ctsk, but also redirects the stem cells to an aberrant hyperproliferative, chondrogenic state. Further, and unexpectedly, Ctsk-Cre–dependent targeting of MT1-MMP - but not Ctsk, disrupts tendon/ structure by altering a previously undescribed paratenon stem cell-tendon trafficking route. In vivo, MT1-MMP-null tendon stem cells commit to a hyperproliferative, chondrogenic phenotype similar to that observed following tendon/ligament trauma. Based on these new data, we propose that MT1-MMP controls each of these stem cell populations by regulating a mechanotransduction pathway that not only controls YAP/TAZ-linked co-transcriptional programs, but also canonical TFGβ signaling pathways via the proteolytic shedding of the accessory TGFβ receptor, TGFβRIII. Together, these findings outline a new model of MSC function wherein MT1-MMP-dependent collagenolysis and receptor shedding together play a required role in periosteal tissues and tendons. As such, we propose 3 aims; i) characterize the role of MT1-MMP in regulating periosteal stem cell differentiation and function in vitro and in vivo, ii) define a novel role for Ctsk+ tendon stem cells in controlling tendon function and its regulation by MT1-MMP and iii) delineate the impact of MT1-MMP on periosteal/paratenon stem cell YAP/TAZ mechanotransduction and TGFβ/TGFβRIII- dependent differentiation programs. Together, these aims should cast new light on a family of specialized stem cells that require MT1- MMP-dependent proteolysis to not only regulate intramembranous bone formation, but also tendon structure/function as well.

抽象的 骨骼以及肌腱都包含嵌入I型胶原蛋白富含组织中的干细胞群体。骨 骨髓和内接内膜的干细胞通过内软骨骨化产生骨骼，而骨膜茎 细胞通过膜内途径形成骨骼。反过 成熟的组织。最近的研究已经确定半胱氨酸蛋白酶组织蛋白酶K（CTSK）是一种独特的 骨膜干细胞的标记，我们已经确认了这一发现，但这也导致了我们对迄今的识别 与肌腱相关的未表征的第二个茎种群。在骨髓来源的MSC中，我们有 先前确定了膜锚定金属蛋白酶MT1-MMP的新需求 调节机械敏感的YAP/TAZ依赖性途径，该途径通过 周围胶原基质的蛋白水解重塑。相比之下，MT1-MMP和 骨膜或肌腱/韧带干细胞中的CTSK尚不清楚。使用CTSK-CRE转基因线进行目标 骨膜干细胞，我们发现单独靶向的MT1-MMP在体内引起了深刻的骨质减少状态 仅与CTSK独立运行，但也将干细胞重定向到异常的高增殖性， 软骨态。此外，出乎意料的是，MT1-MMP的CTSK-CRE依赖性靶向 - 但不是CTSK， 通过改变先前未描述的帕拉特农干细胞倾斜途径来破坏肌腱/结构。在 Vivo，MT1-MMP-NULL肌腱干细胞致力于类似的软骨表型超增殖剂的软骨表型 观察到肌腱/韧带创伤。基于这些新数据，我们建议MT1-MMP控制 这些干细胞种群中的每一个都通过调节不仅控制的机械转导途径 yap/taz连接的共转录程序，但也通过蛋白水解的规范TFGβ信号通路 辅助TGFβ受体TGFβRIII的脱落。这些发现一起概述了MSC的新模型 其中MT1-MMP依赖性胶原完全溶解和接收器一起脱落的功能在 骨膜组织和肌腱。因此，我们提出了3个目标。 i）表征MT1-MMP在调节中的作用 骨膜干细胞分化和体外和体内功能，ii）定义CTSK+腱茎的新作用 控制肌腱功能的细胞及其通过MT1-MMP和III的调节）描绘了MT1-MMP的影响 骨膜/paratenon干细胞YAP/TAZ机械转导和TGFβ/TGFβRIII-依赖性分化 程序。总之，这些目标应给需要MT1-的专门干细胞家族投放新的灯光。 MMP依赖性蛋白水解不仅调节膜内骨形成，还调节肌腱 结构/功能也是如此。