MGF

MGF Peptide

Mechano-growth factor (MGF) constitutes a variant of insulin-like growth factor 1 (IGF-1), specifically identified as the IGF-1Eb isoform. It performs an essential function in facilitating muscle remodeling, cellular proliferation, and cell survival. Contemporary studies indicate this isoform can additionally trigger satellite cell activation in skeletal muscle, provide neuronal protection, and combat age-related muscle deterioration.

The principal function of MGF involves enabling rapid muscle repair, especially following physical exertion or injury. Experimental investigations in rats show MGF levels rise substantially after muscle damage, with elevated expression closely linked to improved muscle cell growth, regeneration, and differentiation.

MGF Peptide Description

IGF-1 occurs in several isoforms produced through alternative splicing of the IGF-1 gene. One of these, termed mechano-growth factor (MGF or IGF-1Ec in human nomenclature), possesses a unique E-domain sequence that provides distinct biological functions compared to other IGF-1 variants. Research suggests that while systemic IGF-1 primarily drives cell growth and differentiation, MGF serves a specialized function in activating progenitor cells and enabling tissue repair in response to mechanical stress.

MGF levels have been noted to increase substantially following eccentric exercise, mechanical strain, or injury. Experimental evidence indicates MGF operates through the PI3K/Akt and MAPK signaling pathways, which are fundamental to cell survival, proliferation, and anti-apoptotic responses. Additional studies propose MGF produces neuroprotective effects in neuronal cell systems, assisting in minimizing apoptosis and supporting axonal regeneration.

In laboratory environments, synthetic MGF peptides are employed to investigate biological processes involved in muscle hypertrophy, tissue regeneration, and neurorepair. Their functional stability and bioavailability depend primarily on peptide sequence optimization and resistance to enzymatic degradation under in vitro conditions.

MGF Peptide Research Findings

MGF and Skeletal Muscle Restoration

Studies utilizing experimental models reveal MGF expression increases in response to muscle overload and mechanical stress. The peptide has shown capacity to promote satellite cell proliferation while postponing early differentiation, thereby improving skeletal muscle's regenerative potential.

MGF and Neural Protection

In neuronal investigations, MGF has been discovered to activate cell survival pathways through Akt phosphorylation, helping prevent apoptosis resulting from oxidative or ischemic stress. These findings have prompted additional research into MGF's potential function in neuronal repair and axonal growth.

MGF and Cellular Restoration Mechanisms

MGF appears to control genes involved in cell-cycle progression, DNA synthesis, and anti-apoptotic processes. In vitro results indicate MGF-treated cells display enhanced proliferation and repair capability compared to untreated controls, indicating unique signaling pathways distinct from systemic IGF-1 activity.

MGF and Heart Research

Preclinical investigation on cardiac tissues has revealed transient elevations in MGF expression following myocardial injury. Results suggest MGF may contribute to cardiac repair and cytoprotective mechanisms by affecting survival signaling pathways and boosting fibroblast activity.

MGF and Aging-Related Decline

Research indicates MGF expression diminishes with age across various experimental models, which may be connected to reduced muscle mass and decreased regenerative capacity. Administration of synthetic MGF in aging models has been investigated for its potential to enhance local IGF signaling and activate muscle stem cells.

The Mechano Growth Factor peptide is provided strictly for research and laboratory use only. It is not approved for human or animal therapeutic applications.

Literature Review Author

This literature review was compiled, edited, and organized by Dr. Geoffrey Goldspink, Ph.D., Professor Emeritus of Muscle Biology and Molecular Physiology at University College London (UCL).

Dr. Goldspink is widely regarded as the pioneering scientist who first identified and characterized Mechano-Growth Factor (MGF), a splice variant of the IGF-1 gene activated by mechanical stimuli. His groundbreaking research has elucidated how MGF contributes to muscle adaptation, repair, and protection against age-related atrophy. Through decades of molecular physiology studies, Dr. Goldspink's work has become foundational to the understanding of muscle remodeling and IGF-1 gene regulation.

Scientific Journal Author

This article draws upon the collective scientific contributions of Dr. Geoffrey Goldspink, Dr. S.Y. Yang, Dr. G. McKoy, Dr. P. Mills, and collaborators whose studies have advanced knowledge of the IGF-1Ec (MGF) isoform.

Their published research in journals such as FEBS Letters, The Journal of Physiology, and Experimental Gerontology has demonstrated that MGF plays a critical role in activating muscle satellite cells, promoting tissue repair, and providing neuroprotective and cardioprotective effects. Together, their findings have shaped the modern scientific understanding of MGF signaling, muscle regeneration, and age-related muscle decline.

Reference Citations

Yang SY, Goldspink G. Different roles of the IGF-I Ec peptide (MGF) and mature IGF-I in myoblast proliferation and differentiation. FEBS Lett. 2002;522(1-3):156–160.

McKoy G, Ashley W, Mander J, Yang SY, Williams N, Russell B, Goldspink G. Expression of IGF-1 splice variants and structural genes in rabbit skeletal muscle induced by stretch and stimulation. J Physiol. 1999;516(Pt 2):583–592.

Goldspink G. Mechanical signals, IGF-I gene splicing, and muscle adaptation. Physiology (Bethesda). 2005;20:232-238.

Owino V, Yang SY, Goldspink G. Age-related loss of skeletal muscle function and the role of MGF splice variant of IGF-1. J Musculoskelet Neuronal Interact. 2001;2(3):195–198.

Mills P, Nader GA. Regulation of muscle stem cell fate by IGF-1 and MGF signaling. Exp Gerontol. 2006;41(12):1114-1121.

Ramer MS, Priestley JV, McMahon SB. Functional regeneration of sensory axons into the adult spinal cord. Nature. 2000;403(6767):312-316.

Kandalla PK, Goldspink G, Butler-Browne G, Mouly V. Mechano Growth Factor activates human muscle progenitor cells and modulates their differentiation. J Cell Physiol. 2011;226(7):1743-1750.

Quesada A, Etayo-Labiano I, Villalba M, et al. Mechano-growth factor and IGF-I receptor signaling in neuroprotection. J Neurosci Res. 2007;85(10):2139-2148.

Mills P, Goldspink DF, et al. MGF and the adaptive response to mechanical loading in skeletal muscle. Biochem Soc Trans. 2003;31(Pt 6):1191-1196.

Zhao J, Li X, et al. Expression of mechano-growth factor after myocardial infarction and its effect on cardiomyocyte apoptosis. Biochem Biophys Res Commun. 2009;382(3):580-584.

Hameed M, Lange KH, Andersen JL, Schjerling P, Kjaer M, Harridge SD. The effect of recombinant human growth hormone and resistance training on IGF-I splice variant expression in older men. J Physiol. 2004;555(Pt 1):231-240.

McMahon CD, Popovic L, Oldham JM, Jeanplong F, Osepchook CC, Hodgkinson SC, Sheard PW, Dixon MW, Knowles SE, Bass JJ. GH dependence of skeletal muscle IGF-I and MGF mRNA expression. Am J Physiol Endocrinol Metab. 2003;284(4):E671-E678.

Yang SY, Alnaqeeb M, Simpson H, Goldspink G. Cloning and characterization of an IGF-I isoform expressed in skeletal muscle subjected to stretch. J Muscle Res Cell Motil. 1996;17(4):487–495.

Philippou A, Halapas A, Maridaki M, Koutsilieris M. Type I IGF-1 Ec (MGF) expression in exercising skeletal muscle. Histol Histopathol. 2007;22(6):603–618.

Quesada A, Romeo HE, Micevych P. IGF-1 and MGF expression in hippocampal neurons: neuroprotective role in aging. Neuroscience. 2009;162(1):64-73.