Angiogenesis in adipose tissue is promoted by insulin-like growth factor 1 signaling. We analyzed whether this regulatory mechanism also improves the angiogenic activity of adipose tissue–derived microvascular fragments. Murine adipose tissue–derived microvascular fragments were cultivated for 24 h in the University of Wisconsin (UW) solution supplemented with vehicle, insulin-like growth factor 1, or a combination of insulin-like growth factor 1 and insulin-like growth factor–binding protein 4. Subsequently, we assessed their cellular composition, viability, proliferation, and growth factor expression. Moreover, cultivated adipose tissue–derived microvascular fragments were seeded onto collagen–glycosaminoglycan scaffolds, which were implanted into dorsal skinfold chambers to study their vascularization and incorporation. Insulin-like growth factor 1 increased the viability and growth factor expression of adipose tissue–derived microvascular fragments without affecting their cellular composition and proliferation. Accordingly, scaffolds containing insulin-like growth factor 1–stimulated adipose tissue–derived microvascular fragments exhibited an enhanced in vivo vascularization and incorporation. These positive insulin-like growth factor 1 effects were reversed by additional exposure of adipose tissue–derived microvascular fragments to insulin-like growth factor–binding protein 4. Our findings indicate that insulin-like growth factor 1 stimulation of adipose tissue–derived microvascular fragments is suitable to improve their vascularization capacity.
Increased Circulating Insulin-like Growth Factor-1 in Late-onset Alzheimer's Disease