Mechanisms responsible for exercise-induced alterations in hematopoiesis

造血干细胞(HSCs)是造血系统最原始的细胞，在整个生命周期内负责维持和再生所有成熟的血细胞。HSC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。间充质基质细胞(MSCs)是HSC生态位的主要组成部分。骨髓间充质干细胞通过分化为成骨细胞或脂肪细胞，为干细胞生态位的细胞成分做出贡献。此外，MSCs通过产生和分泌直接调节HSC命运的造血细胞生长因子和细胞因子，为HSC利基的可溶性成分做出贡献。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。我们最近的实验数据表明，MSCs是运动诱导的HSCs改善的关键机制环节。然而，MSCs在运动反应中调节HSCs的确切机制仍未完全阐明，部分原因是缺乏MSC识别的特定标记物。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