MGF dosage protocol

What the compound is

Mechano Growth Factor (MGF), also known as IGF-1Ec, is an alternative splicing variant of Insulin-like Growth Factor I (IGF-I) (PMID 15501012, PMID 20494600). IGF-I is a crucial growth factor involved in embryonic development, postnatal growth, tissue repair, and maintaining tissue balance (homeostasis) (PMID 20494600). MGF is distinct from the systemic or liver type IGF-IEa because it has a different peptide sequence and functions as a local tissue repair factor (PMID 15501012, PMID 20494600). The ability to produce MGF in the body declines with age, similar to the decline in circulating growth hormone (GH) levels (PMID 15501012).

How it is thought to work

MGF is expressed in response to physical activity and is responsible for replenishing satellite (stem) cells in skeletal muscle (PMID 15501012). It responds to changes in physiological conditions or environmental stimuli (PMID 20494600). MGF expression significantly increases in muscle, bone, and tendons following damage from mechanical stimuli (animal studies) (PMID 20494600). In the brain and heart, MGF expression also increases after ischemia (animal studies) (PMID 20494600). MGF has been shown to activate satellite cells in muscle, leading to muscle growth (hypertrophy) or regeneration (PMID 20494600). It also acts as a neuroprotectant in brain ischemia (animal studies) (PMID 20494600). The expression and processing of MGF are tissue-specific, but its precise functional mechanism is not yet fully understood (PMID 20494600).

What laboratory and animal studies report

Experimental animal studies have examined MGF and a short derivative as potential therapies for muscular dystrophy and cerebral hypoxia-ischemia (PMID 20494600). In pigs, African swine fever virus (ASFV)-encoded proteins MGF_110-3L and MGF_110-4L were shown to bind Toll-like receptor 2 (TLR2), activating immune signaling and leading to strong production of pro-inflammatory cytokines, causing severe inflammation and pathology (animal and cell studies) (PMID 42446133). ASFV strains lacking these proteins caused reduced cytokine responses in vitro and impaired inflammatory pathology in pigs (animal and cell studies) (PMID 42446133).

Human evidence so far

Growth hormone (GH) treatment in older people upregulates IGF-I gene expression. When combined with resistance exercise, more is spliced towards MGF, which is expected to improve muscle response to physical activity (human studies) (PMID 15501012). The possibility of using MGF to ameliorate sarcopenia (age-related muscle loss) is a subject of discussion (PMID 15501012).

Key terms explained

**Alternative splicing:** A process where different protein variants can be produced from a single gene (PMID 15501012, PMID 20494600).

**Sarcopenia:** The loss of muscle mass, a significant problem associated with aging (PMID 15501012).

**Satellite cells:** Stem cells located in skeletal muscle that contribute to muscle repair and growth (PMID 15501012, PMID 20494600).

**Ischemia:** A restriction in blood supply to tissues, causing a shortage of oxygen and glucose needed for cellular metabolism (PMID 20494600).