Isthmin: A multifunctional secretion protein

Isthmin is a polypeptide secreted by adipocytes that was first detected in Xenopus gastrula embryos. Recent studies have focused on the biological functions of isthmin in growth and development, angiogenesis, and metabolism. Distinct spatiotemporal expression of isthmin-1 (ISM-1) was observed during growth and development. ISM-1 plays an important role in the occurrence and development of cancer by regulating cell proliferation, migration, angiogenesis, and immune microenvironments. Moreover, ISM-1, as a newly identified insulin-like adipokine, increases adipocyte glucose uptake and inhibits hepatic lipid synthesis. However, the biological function of ISM-1 remains largely unknown. In this review, we highlight the structure and physiological functions of isthmin and explore its application potential, contributing to a better understanding of its function and providing prevention and treatment strategies for various diseases.