Mechanisms and clinical prospects of mesenchymal stem cells and their derivatives in treating hypothyroidism-induced injuries: A focus on cardiovascular, skeletal muscle, and nervous systems.

Hypothyroidism, a prevalent endocrine disorder characterized by insidious onset and prolonged progression, leads to metabolic slowdown and multiorgan dysfunction, significantly compromising patients' quality of life. While hormone replacement therapy improves most patients' serum thyroid function, it faces limitations, including individual response variations, lifelong medication requirements, and potential risks, with no reversal of existing tissue damage. In recent years, the mesenchymal stem cells (MSCs) and their derivatives have gained prominence in immunomodulation and regenerative medicine because of their abundant sources, low immunogenicity, potent paracrine effects, and multidirectional differentiation capabilities for tissue repair. Their unique advantages in modulating the immune microenvironment, promoting angiogenesis, reducing fibrosis, and stimulating endogenous cell regeneration offer novel strategies to overcome treatment bottlenecks in hypothyroidism and its complications, effectively repairing thyroid and multiorgan damage in animal models. This review synthesizes literature from the PubMed and Web of Science databases, incorporating relevant basic research and clinical trials. This study examined the systemic impacts of hypothyroidism, evaluated the experimental and clinical roles of the MSCs in thyroid tissue reconstruction and organ protection, and analyzed molecular mechanisms, including immune regulation, the antioxidant stress response, anti-apoptosis, and cellular function restoration. Clinical application potential is assessed alongside critical challenges such as standardized preparation, long-term safety, in vivo homing efficiency, and large-scale production.