Mesenchymal stem cell secretome (MSC secretome)

The Mesenchymal stem cell (MSC) secretome represents the complete set of bioactive molecules secreted by MSCs, including soluble proteins and membrane-bound extracellular vesicles. It serves as the primary mediator of the therapeutic effects observed in MSC-based therapies, shifting the paradigm from cell replacement to paracrine-mediated tissue repair and immunomodulation. The secretome contains a diverse array of cytokines, growth factors, and microRNAs that interact with multiple host cell receptors to suppress inflammation, inhibit apoptosis, and stimulate endogenous regenerative processes. In clinical settings, the MSC secretome is being explored as a cell-free alternative to traditional stem cell transplantation for treating conditions such as graft-versus-host disease, myocardial infarction, and chronic wounds. Its multi-target mechanism of action allows it to address complex pathologies that involve both immune dysregulation and tissue damage. However, the inherent complexity and variability of the secretome pose significant challenges for pharmacological standardization and regulatory approval.

Other names

MSC-derived paracrine factorsMesenchymal stem cell-conditioned mediumMSC-CMMSC-derived extracellular vesiclesMSC-EVsMSC-derived exosomesMesenchymal stromal cell secretome

The MSC secretome functions by releasing a cocktail of paracrine factors such as TGF-beta, PGE2, IDO, TSG-6, VEGF, and HGF, which bind to multiple host cell receptors (e.g., TGFBR, EP2/EP4, VEGFR, HGFR) to activate intracellular signaling pathways like PI3K/Akt, MAPK, and STAT3, leading to immunomodulation and tissue regeneration.