Biomaterial Database

Insulin receptors and insulin-like growth factor I receptors are functional during organogenesis of the lens. 1990

J Alemany, and M Girbau, and L Bassas, and F de Pablo

Section on Receptors and Hormone Action, NIDDK, National Institutes of Health, Bethesda, MD 20892.

Insulin and insulin-like growth factor I (IGF-I) stimulate overall growth and development of the chick embryo in early organogenesis. Turning to individual organs, to clarify the cellular effects of these peptides and the activity of the receptors involved, we had demonstrated with developing lens that insulin and IGF-I increase the accumulation of delta-crystallin mRNA, a marker for lens differentiation, in part by stimulation of transcription. In this study we expand our previous work on lens receptors to an earlier time in organogenesis, day 4, which marks the beginning of differentiation of the lens epithelial cells into elongated fibers. Insulin receptors are demonstrable by affinity cross-linking in epithelial cells at day 6, and specific binding of [125I]insulin and [125I]IGF-I is detectable in day 4 lenses. Insulin and IGF-I stimulation of substrate phosphorylation in the presence of solubilized receptors occurs only with high concentrations (10-100 nM) of either peptide in day 4 lenses, while a clear response with low concentrations (1 nM) is elicited by day 6 of development. Low concentrations of both insulin and IGF-I (0.1-1 nM) increase the incorporation of [3H]leucine and [3H]uridine in day 6 lens cells, suggesting that each peptide acts through its own receptor. These results confirm and extend the finding of insulin and IGF-I receptors in the developing chicken lens, and demonstrate their functional activity. This embryonic model should be valuable for further analysis of the action of insulin and IGF-I in growth and differentiation processes during early development.

UI	MeSH Term	Description	Entries
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007334	Insulin-Like Growth Factor I	A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on GROWTH HORMONE. It is believed to be mainly active in adults in contrast to INSULIN-LIKE GROWTH FACTOR II, which is a major fetal growth factor.	IGF-I,Somatomedin C,IGF-1,IGF-I-SmC,Insulin Like Growth Factor I,Insulin-Like Somatomedin Peptide I,Insulin Like Somatomedin Peptide I
D007908	Lens, Crystalline	A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.	Eye Lens,Lens, Eye,Crystalline Lens
D007930	Leucine	An essential branched-chain amino acid important for hemoglobin formation.	L-Leucine,Leucine, L-Isomer,L-Isomer Leucine,Leucine, L Isomer
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D011972	Receptor, Insulin	A cell surface receptor for INSULIN. It comprises a tetramer of two alpha and two beta subunits which are derived from cleavage of a single precursor protein. The receptor contains an intrinsic TYROSINE KINASE domain that is located within the beta subunit. Activation of the receptor by INSULIN results in numerous metabolic changes including increased uptake of GLUCOSE into the liver, muscle, and ADIPOSE TISSUE.	Insulin Receptor,Insulin Receptor Protein-Tyrosine Kinase,Insulin Receptor alpha Subunit,Insulin Receptor beta Subunit,Insulin Receptor alpha Chain,Insulin Receptor beta Chain,Insulin-Dependent Tyrosine Protein Kinase,Receptors, Insulin,Insulin Receptor Protein Tyrosine Kinase,Insulin Receptors
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D000345	Affinity Labels	Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.	Affinity Labeling Reagents,Labeling Reagents, Affinity,Labels, Affinity,Reagents, Affinity Labeling
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia