Mechanisms responsible for exercise-induced alterations in hematopoiesis

造血干细胞（hsc）是造血系统中最原始的细胞，在整个生命周期中负责所有成熟血细胞的维持和再生。造血干细胞位于骨髓内，其功能受其微环境或生态位内的细胞和可溶性因子的调节。间充质间质细胞（MSCs）是造血干细胞生态位的主要组成部分。间充质干细胞通过分化成成骨细胞或脂肪细胞，为造血干细胞生态位的细胞成分做出贡献。此外，间充质干细胞通过产生和分泌造血生长因子和细胞因子来促进造血干细胞生态位的可溶性成分，直接调节造血干细胞的命运。PI实验室公布的数据表明，急性运动和运动训练可以改善HSC的数量和功能。我们最近的试点数据表明，MSCs是负责运动诱导的hsc改善的关键机制环节。然而，由于缺乏MSC识别的特异性标记物，MSCs在调节hsc对运动反应中的作用的确切机制仍有待充分阐明。最近开发的小鼠模型允许对MSCs进行前瞻性鉴定

Hematopoietic (blood-forming) stem cells (HSCs) are the most primitive cells of the hematopoietic system, and are responsible for the maintenance and regeneration of all mature blood cells throughout the lifespan. HSC are located within the bone marrow, and their function is regulated by cellular and soluble factors within their microenvironment or niche. Mesenchymal stromal cells (MSCs) are a primary component of the HSC niche. MSCs contribute to the cellular components of the HSC niche by differentiating into osteoblasts or adipocytes. Additionally, MSCs contribute to the soluble components of the HSC niche by producing and secreting hematopoietic growth factors and cytokines that directly regulate HSC fate. Published data from the PI’s lab has demonstrated that acute exercise and exercise training improves HSC quantity and function. Our recent pilot data implicates MSCs as a key mechanistic link responsible for exercise-induced improvements in HSCs. However, the precise mechanisms responsible for the role of MSCs in regulating HSCs in response to exercise remain to be fully elucidated due, in part, to a lack of specific markers for MSC identification. Recently developed mouse models that allow for prospective identification of MSCs