Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism(s) by which insulin enhance prematurely the activity of brush border membrane (BBM) hydrolases in rat immature intestine is unknown. Therefore, we have compared the responses of four BBM enzymes [sucrase-isomaltase (SI), maltase, lactase-phloridzine hydrolase (LPH), and aminopeptidase] with exogenous insulin, the analog B-Asp10, IGF-I, and antireceptor MAb [insulin-receptor (IR) MAb] given to preweaning pups. Low doses of insulin caused a precocious induction of SI and of SI mRNA and stimulated maltase activity without effect on LPH nor on aminopeptidase activities. IGF-I given at the same dose as that of insulin had no detectable effect on these enzymes. Administration to sucklings of IR MAb prevented the effect of endogenous insulin by inhibiting the expression of SI and maltase without effect on LPH activity. B-Asp10, an insulin analogue that exhibits in vitro a 3.5-fold increase in receptor affinity with sustained signaling of the receptor tyrosine kinase, caused an overexpression of SI by 3.5-fold and of maltase by 1.5-fold compared with equivalent doses of normal insulin. The premature increases in SI activity, SI mRNA, and maltase activity in response to insulin were dose-dependent and were associated with dose-dependent increases in intracellular spermine and spermidine concentrations. In conclusion, these data suggest that the premature induction of SI by insulin is mediated by a dose-dependent signal initiated by binding of the hormone to its intestinal receptor, which after transduction into the cell indirectly triggers the transcription of the SI gene, possibly by changes in intracellular polyamine concentrations.
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PMID:Premature stimulation of rat sucrase-isomaltase (SI) by exogenous insulin and the analog B-Asp10 is regulated by a receptor-mediated signal triggering SI gene transcription. 958 3

Curcumin, the bioactive component of curry spice turmeric, and its related structures possess potent anti-oxidant and anti-inflammatory properties. Several lines of evidence suggest that curcumin may play a beneficial role in animal models of diabetes, both by lowering blood glucose levels and by ameliorating the long-term complications of diabetes. However, current understanding of the mechanism of curcumin action is rudimentary and is limited to its anti-oxidant and anti-inflammatory effects. In this study we examine potential anti-diabetic mechanisms of curcumin, curcumin C3 complex), and tetrahydrocurcuminoids (THC). Curcuminoids did not exert a direct effect on receptor tyrosine kinase activity, 2-deoxy glucose uptake in L6-GLUT4myc cells, or intestinal glucose metabolism measured by DPP4/alpha-glucosidase inhibitory activity. We demonstrate that curcuminoids effectively suppressed dexamethasone-induced phosphoenol pyruvate carboxy kinase (PEPCK) and glucose6-phosphatase (G6Pase) in H4IIE rat hepatoma and Hep3B human hepatoma cells. Furthermore, curcuminoids increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target acetyl-CoA carboxylase (ACC) in H4IIE and Hep3B cells with 400 times (curcumin) to 100,000 times (THC) the potency of metformin. These results suggest that AMPK mediated suppression of hepatic gluconeogenesis may be a potential mechanism mediating glucose-lowering effects of curcuminoids.
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PMID:Curcumin activates AMPK and suppresses gluconeogenic gene expression in hepatoma cells. 1966 95