Our lab studies insulin-like growth factor-I (IGF-I) synthesis and action throughout the life span. IGF-I is a 70 amino acid peptide synthesized primarily by the liver, which secretes this growth factor into the circulation. Most extra-hepatic tissues also synthesize IGF-I. Thus, IGF-I acts as both a circulating endocrine and autocrine/paracrine growth factor. IGF-I acts by binding to a heterotetrameric receptor with inherent tyrosine kinase activity. IGF-I binding stimulates the tyrosine kinase activity of the receptor resulting in a sequence of biochemical events that cause the activation of two major signaling kinases. One of these is the lipid kinase phosphatidylinositol 3-kinase (PI3K) and the other is the extracellular signal regulated kinase (ERK). Products of PI3K lead to the activation of a number of downstream kinases, most notably Akt/protein kinase B. ERK phosphorylates a variety of substrates. Collectively, these actions lead to increased cellular proliferation, survival, anabolism, and differentiated function.
Gong Z, Kennedy O, Sun H, Wu Y, Williams GA, Klein L, Cardoso L, Matheny RW Jr, Hubbard GB, Ikeno Y, Farrar RP, Schaffler MB, Adamo ML, Muzumdar RH, Yakar S. Reductions in serum IGF-1 during aging impair health span. Aging Cell. 2013 Dec 17.
Ford JJ, Yeh LC, Schmidgal EC, Thompson JF, Adamo ML, Lee JC. Protein kinase D1 is essential for bone acquisition during pubertal growth. Endocrinology. 2013 Nov;154(11):4182-91.
Yeh LC, Ma X, Ford JJ, Adamo ML, Lee JC. Rapamycin inhibits BMP-7-induced osteogenic and lipogenic marker expressions in fetal rat calvarial cells. J Cell Biochem. 2013 Aug;114(8):1760-71.
Thakur S, Garg N, Adamo ML. Deficiency of insulin-like growth factor-1 receptor confers resistance to oxidative stress in C2C12 myoblasts. PLoS One. 2013 May 10;8(5):e63838.
Hinchee-Rodriguez K, Garg N, Venkatakrishnan P, Roman MG, Adamo ML, Masters BS, Roman LJ. Neuronal nitric oxide synthase is phosphorylated in response to insulin stimulation in skeletal muscle. Biochem Biophys Res Commun. 2013 Jun 7;435(3):501-5