MGF

MGF (Mechano Growth Factor) is a splice variant of the IGF-1 gene (IGF-1Ec in humans) that is expressed in response to mechanical overload and damage in muscle tissue. Unlike systemic IGF-1, MGF acts primarily as a local repair factor, activating muscle satellite (stem) cells and initiating the repair cascade following exercise-induced muscle damage.

MGF is produced when muscle tissue is subjected to mechanical stress (such as resistance exercise), triggering alternative splicing of the IGF-1 gene. The resulting MGF peptide contains a unique C-terminal E-domain that distinguishes it from other IGF-1 splice variants. This E-domain is responsible for activating quiescent satellite cells, recruiting them into the cell cycle to begin proliferation before differentiation into mature muscle fibers. PEG-MGF is a modified version with polyethylene glycol attached to extend its short half-life.

Research has demonstrated that MGF expression increases significantly following eccentric exercise and muscle damage. Studies have shown that MGF administration can activate satellite cells, promote muscle hypertrophy, and enhance recovery from muscle injury. Animal research has demonstrated neuroprotective effects and improved cardiac function following ischemic injury. The localized, autocrine/paracrine nature of MGF's action makes it distinct from systemic growth factors and particularly relevant to tissue-specific repair mechanisms.