IGF-1

Androgenetic alopecia (AGA), the most prevalent form of hair loss, urgently requires breakthroughs in existing therapies due to limitations such as medication side effects, recurrence risks, and treatment inefficacy. Herein, we propose an insulin-derived self-assembling sequence Ac-GFFY, combined with the C domain peptide of insulin-like growth factor 1, successfully designing an IGF-1 biomimetic peptide factor, Ac-GFFY-IGF, which can substitute for the absent IGF-1 in the AGA pathological environment and facilitate hair regrowth. Compared with IGF-1, Ac-GFFY-IGF exhibits superior in vitro stability and enhanced skin permeability. In the murine AGA model, Ac-GFFY-IGF demonstrated superior efficacy to the clinically used minoxidil, achieving faster hair regeneration, higher hair quality, and broader hair coverage at lower concentrations. Our strategy provides a critical theoretical foundation and technical pathway for developing novel mechanism-driven therapies for AGA.

The domesticated poultry is invaluable as a global protein source. Growth performance in poultry, particularly broilers, plays a critical role in production efficiency. Insulin-like growth factor-1 (IGF-1) is a multifunctional hormone which shows promotive effects on growth and development. Traditional IGF-1 delivery methods, such as injections or dietary supplements, face practical limitations including high cost, multiple dosages and rapid degradation. To explore a more efficient IGF-1 delivery method for promoting chicken growth, we generated a recombinant herpesvirus of turkey expressing chicken IGF-1, rHVT-chIGF-1. A single dose of rHVT-chIGF-1 was administered intramuscularly to broilers at day 1 of age. Growth performance parameters, including body weight (BW) and average daily weight gain (ADG) was assessed over a 42-day period. The results showed that, at both 35 and 42 days of age, the rHVT-IGF-1 group showed significantly higher BW and ADG compared to the HVT group (35d BW: p = 0.0063; 42d BW: p < 0.0001; 35d ADG: p < 0.0001; 42d ADG: p < 0.0001) and the blank control group (35d BW: p = 0.0189; 42d BW: p = 0.0032; 35d ADG: p < 0.0001; 42d ADG: p < 0.0001). The cross-sectional area (CSA) of pectoral and leg muscle fibres was significantly greater in chickens from the rHVT-chIGF-1 group compared to those in the HVT vector (p = 0.0078) and blank control (p = 0.025) groups. Additionally, the mRNA expression of muscle development-related genes was significantly upregulated in the rHVT-chIGF-1 group. These findings suggest that rHVT-chIGF-1 is a novel and effective in vivo delivery system for promoting chicken growth, offering an alternative to traditional IGF-1 delivery methods.