Insulin-like-growth-factor
Synonym(s)
IGF; IGF1; IGF-1; IGF-I; IGF-II; Insulin-like growth factor; Insulin-like-growth-factor-I; Insulin-like-growth-factor-II; SM-A; Somatomedin A; Somatomedin C
DefinitionThis section has been translated automatically.
Polypeptides with high sequence homology to insulin. Their synthesis takes place primarily in the liver. The "insulin-like-growth-factors" are part of a complex system of growth factors (GH = growth factor), which body cells use to communicate with their environment. This system consists of two membrane receptors (IGF1R and IGF2R), two ligands, a group of six IGF binding proteins (IGFBP 1-6), and some IGFBP-associated proteases.
General informationThis section has been translated automatically.
- IGF-1: Growth factor structurally very similar to insulin. Like IGF-2, it is mainly secreted by the liver after stimulation. An influence of IGF-1 on the regulation of physiological as well as pathological states (here especially in tumor development) has been demonstrated. Meals with a high glycaemic load lead to an induction of insulin and IGF-1, and influences on cell proliferation and inhibition of apoptosis have been described. IgF-1 shows the highest physiological serum concentrations in adolescence between 15 and 20 years of age. IGF-1 seems to play a role in the pathogenesis of acne vulgaris. An IGF-1 gene polymorphism associated with acne has been identified (Tasli L et al. 2013). IGE-1 induces proliferation in keratinocytes. Furthermore, it inhibits the transcription factor FoxO1 in sebocytes (Mirdamadi Y et al. 2015). FoxO1 is a suppressor of important transcription factors in lipid synthesis. As a consequence, IGF-1 induces sebocyte lipogenesis and acts costimulatively with androgens in sebocytes with respect to proliferation and lipogenesis. The facial sebum concentration correlates with the IGF-1 serum concentration in male acne patients.
- IGF-2: Plays an important role in early cell development, e.g. in the development of infant hemangiomas (here an upregulation of IgF-2 could be shown), while IGF-1 is rather responsible for growth acceleration at a later stage.
LiteratureThis section has been translated automatically.
- Mirdamadi Y et al (2015) Insulin and insulin-like-growth-factor-1 can modulate thephosphoinositide-3-kinase/Akt/FoxO1
pathway in SZ95 sebocytes in vitro.
Mol cell endocrinol 415:32-44. - Plewig G (2010) How does acne vulgaris develop? dermatologist 61: 99-106
- Tasli L et al (2013) Insulin-like growth factor-I gene polymorphism in acne vulgaris. J Eur Acad Dermatol Venereol 27: 254-257.