Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding of 125I-labeled mouse epidermal growth factor (EGF) to 18 cell lines, including HeLa (human carcinoma), MDCK (dog kidney cells), HTC (rat hepatoma), K22 (rat liver), HF (human foreskin), GM17 (human skin fibroblasts), XP (human xeroderma pigmentosum fibroblasts), and 3T3-L1 (mouse fibroblasts), was inhibited by saccharin and cyclamate. The human cells were more sensitive to inhibition by these sweeteners than mouse or rat cells. EGF at doses far above the physiological levels reversed the inhibition in rodent cells but not in HeLa cells. In HeLa cells, the doses of saccharin and cyclamate needed for 50% inhibition were 3.5 and 9.3 mg/ml, respectively. Glucose, 2-deoxyglucose, sucrose, and xylitol did not inhibit EGF binding. Previous studies have shown that phorbol esters, strongly potent tumor promoters, also inhibit EGF binding to tissue culture cells. To explain the EGF binding inhibition by such greatly dissimilar molecules as phorbol esters, saccharin, and cyclamate, it is suggested that they operate through the activation of a hormone response control unit.
 ...
PMID:Saccharin and cyclamate inhibit binding of epidermal growth factor. 626 53

Nucleotide excision repair (NER) of damaged DNA is operated by a complex network of DNA repair enzymes that include a protein termed xeroderma pigmentosum complementation group D (XPD). We have previously reported that the expression of XPD is regulated by activation of the insulin receptor and that mutations of the tyrosine kinase domain of the receptor inhibit the insulin-dependent increase in XPD messenger RNA (mRNA) and protein levels. In the present study, we characterize the insulin-dependent signaling pathway leading to the control of XPD expression. Using Chinese hamster ovary (CHO) cells transfected with the human insulin receptor, we demonstrated that the effect of insulin on XPD mRNA levels was mediated via the RAS-signaling and the p70 S6 kinase pathways. On the other hand, the intracellular level of XPD protein was under the exclusive control of the activation of the RAS-dependent cascade in response to insulin. We also studied the effect of acute and chronic exposures to different concentrations of glucose on the insulin-dependent regulation of intracellular XPD levels. A short-term exposure (48 h) to increasing concentrations of glucose potentiated the insulin-dependent regulation of XPD, and this was associated with an efficient protection against glucose-dependent damage to cellular DNA, as determined by the comet assay. Conversely, in cells that were grown for 3 weeks in the presence of glucose concentration greater than 10 mM, the capability of insulin to regulate the level of XPD was significantly reduced, and this promoted a glucose-dependent accumulation of products of DNA damage. In conclusion, glucose and insulin are important regulators of XPD, and prolonged exposure to toxic levels of glucose reduces the insulin-dependent regulation of DNA repair.
 ...
PMID:Insulin and glucose regulate the expression of the DNA repair enzyme XPD. 1270 96

Levobupivacaine is one of the major clinical local anesthetics, but it can cause neuron toxic damage. Hyperglycemia can cause neuronal DNA oxidative damage and inhibit expression of the DNA repair gene Xeroderma pigmentosum complementation group D (XPD). This study was designed to determine whether high glucose levels inhibit XPD expression and enhance levobupivacaine-induced DNA damage. We evaluated XPD mRNA and protein expression in SH-SY5Y cells after glucose and levobupivacaine exposure. We next investigated cells reactive oxygen species (ROS) levels, DNA damage and apoptosis with redox-sensitive fluorescent dye DCFH-DA (2',7'-dichlorofluorescein diacetate), comet assays, flow cytometry, and TUNEL (terminal deoxynucleotidyl transferased UTP nick end labeling) assays. XPD expression was inhibited in cells exposed to prolonged high glucose with a concomitant increase in ROS production and more severe DNA damage compared to control culture conditions, and these changes were further exacerbated by levobupivacaine. Our findings indicate that subjects with diabetes may experience more detrimental effects following local anesthetic use.
...
PMID:Increased Oxidative Damage and Reduced DNA Repair Enzyme XPD Involvement in High Glucose-Mediated Enhancement of Levobupivacaine-Induced Neurotoxicity. 2626 62