Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

TNF-alpha has been found in the retina. Hyperoxia and hypoxia regulate TNF-alpha expression. TNF-alpha is an important factor in inflammation and angiogenesis. Dexamethasone inhibits TNF-alpha production. Changes in TNF-alpha expression in the retina may play an important role in the development of oxygen-induced retinopathy. Oxygen-induced retinopathy was produced in C57BL6 mice by exposure to 75% oxygen at Postnatal Day 7 (P7) for 5 days and the mice recovered in room air until Day 17 (P17). Dexamethasone was administered at 0.5 mg/kg/day once daily subcutaneously during the 5 days of oxygen exposure. TNF-alpha expression was evaluated at Day 7 prior to oxygen exposure, at Day 12 (P12) immediately upon removal from oxygen, and at Day 17, the time of maximal vasoproliferation by RT-PCR. TNF-alpha is developmentally regulated in the retinae of C57BL6 mice. From P7 to P12, there is a 3-fold increase in TNF-alpha expression and from P7 to P17 there is a 2.7-fold increase. There was 2.7-fold suppression in expression immediately following oxygen exposure at P12. The expression was dramatically increased at P17, the time of maximal vasoproliferation. Dexamethasone inhibited the expression of TNF-alpha at P17 by 6.4-fold. At this dose, it also suppressed the baseline TNF-alpha expression in the mouse model. In summary, TNF-alpha is altered in the development of oxygen-induced retinopathy in the mouse. It increased markedly during the vasoproliferative phase and was suppressed by dexamethasone. Modulation of TNF-alpha expression may provide a potential site of action for future therapeutic targets.
Mol Genet Metab 2001 Feb
PMID:Dexamethasone alters TNF-alpha expression in retinopathy. 1116 42

Bardet-Biedl syndrome (BBS) is a genetically heterogeneous autosomal recessive disorder with the primary clinical features of obesity, pigmented retinopathy, polydactyly, hypogenitalism, mental retardation and renal anomalies. Associated features of the disorder include diabetes mellitus, hypertension and congenital heart disease. There are six known BBS loci, mapping to chromosomes 2, 3, 11, 15, 16 and 20. The BBS2 locus was initially mapped to an 18 cM interval on chromosome 16q21 with a large inbred Bedouin kindred. Further analysis of the Bedouin population allowed for the fine mapping of this locus to a 2 cM region distal to marker D16S408. Physical mapping and sequence analysis of this region resulted in the identification of a number of known genes and expressed sequence tag clusters. Mutation screening of a novel gene (BBS2) with a wide pattern of tissue expression revealed homozygous mutations in two inbred pedigrees, including the large Bedouin kindred used to initially identify the BBS2 locus. In addition, mutations were found in three of 18 unrelated BBS probands from small nuclear families.
Hum Mol Genet 2001 Apr 01
PMID:Positional cloning of a novel gene on chromosome 16q causing Bardet-Biedl syndrome (BBS2). 1128 52

Traditional linkage analysis in large families is the most promising approach for mapping disease genes of monogenic heritable disorders when the number of informative meioses is sufficient. With rare diseases, however, the low availability of informative pedigrees poses a significant limitation. As an adjunct to family linkage methods, association studies based on the investigation of individual haplotypes from a number of unrelated patients (i.e. linkage disequilibrium analysis) have recently been employed in mapping hereditary disease loci. However, such haplotype analysis is hampered by a number of effects that influence statistical evaluation, e.g. i) population history and size, ii) allele and haplotype frequencies in the respective population(s), iii) heterogeneous mutation and natural selection processes, and iv) small sample sizes of patient groups. The purpose of the present study was to determine the utility and limitations of haplotype-based genetic mapping in estimating the location of the NYX gene, which has recently been identified as the causative gene for a rare inherited retinal disorder known as the complete type of X-linked congenital stationary night blindness (CSNB1). For this purpose we recapitulated haplotypes and tested for linkage disequilibrium in 20 unrelated male CSNB1 patients from three European populations and 44 healthy individuals. All subjects were genotyped for 17 polymorphic microsatellite loci covering the Xp11.4 region with an average marker density of approximately 0.29 cM. We found that a precise model to describe mutations at loci that erroneously break up linkage is highly required, and that the case population must match the respective disease model.
Int J Mol Med 2001 Jul
PMID:Case populations must match the respective disease model: Genotype diversity causes linkage disequilibrium mapping failure in monogenic disorders. 1140 49

An increased thickness of the carotid artery wall is thought to be a sign of early atherosclerosis. Since plasma endothelin concentrations were released from vascular endothelial cells, we have investigated the possible relationship between endothelin 1 (ET-1) and arterial wall thickness. Ninety-eight patients with Type 2 diabetes without evidence of macroangiopathy, hypertension, proteinuria or proliferative retinopathy, and 50 non-diabetic subjects were studied. After an overnight fast, blood was taken for ET-1, glucose, HbA1c, lipids, insulin and C-peptide. Arterial wall thickness was measured as the mean of the maximum intimal-medial thickness (IMT) in 16 carotid segments by B-mode ultrasound. ET-1 levels were significantly elevated in diabetic patients with IMT>1100 microm, 8.3 pmol/l (5.2-12.9) compared with control subjects, 7.6 pmol/l (5.0-11.0), p<0.01 and with diabetic subjects with IMT<500 microm, 7.43 pmol/l (4.8-11.1), p<0.01. The diabetic (IMT>1100 microm) study group had also significantly higher levels of insulin, 102.8 +/- 46.4 pmol/l vs control subjects, 77.5 +/- 32.4 pmol/l, p<0.01. In diabetic subjects, no correlation was found between ET-1 and IMT with glucose, HbA1c, lipids, age or duration of diabetes, respectively. We conclude that ET-1 levels are elevated in Type 2 diabetic patients with increased IMT. Thus providing further support for the role of endothelin in atherosclerosis.
Res Commun Mol Pathol Pharmacol
PMID:Plasma levels of endothelin and early carotid atherosclerosis in diabetic patients. 1175 70

An increased thickness of the carotid artery wall is thought to be a sign of early atherosclerosis. Since vascular endothelium is the site of formation of several substances, we have investigated the rate of progression of carotid atherosclerosis and the contribution of endothelin (ET-1), lipid peroxides [measured as thiobarbituric acid reacting species (TBARS)] and 6-keto-Prostaglandin-F1A (6-keto-PG-F1A) at baseline and after 30-months. Fifty patients with Type 2 diabetes without evidence of macroangiopathy, hypertension, proteinuria or proliferative retinopathy, and 27 healthy, non-diabetic persons were studied. Arterial wall thickness was measured as the mean of the maximum intimal-medial thickness (IMT) in 16 carotid segments by b-mode ultrasound. The IMT values was significantly increased in diabetic subjects (at baseline: 1110 +/- 310 microm, after 30 months: 1260 +/- 280 microm, p < 0.01), but not in control subjects (1100 +/- 280 microm, 1200 +/- 290 microm, respectively). At baseline time both groups had similar levels of ET-1, TBARS and 6-keto-PG-F1A. In 30-months follow-up, the ET-1 level 8.0 pmol/l (5.8-10.7) was significantly elevated in diabetic subjects, compared with the level at baseline time 7.43 pmol/l (4.8-11.1) p < 0.01. No significant differences were found in the other examined parameters in the studied groups. Although insulin levels remained unchanged in the two studied groups, in 30 months follow-up, the insulin level in the diabetic subjects, 92.4 +/- 35.1 pmol/l was significantly elevated compared with those of control subjects 76.0 +/- 31.0 pmol/l, p < 0.05. In conclusion, endothelis is the main associate of the change of IMT value over 30 months in diabetic patients, in whom the extent of atherosclerosis was significantly greater than in control subjects.
Res Commun Mol Pathol Pharmacol
PMID:Progression of carotid atherosclerosis and the role of endothelin in diabetic patients. 1175 71

Vascular endothelial growth factor (VEGF) is a potent endothelial cell-specific mediator of angiogenesis and vasculogenesis. VEGF is involved pathologically in cancer, proliferative retinopathy and rheumatoid arthritis, and as such represents an important therapeutic target. Three classes of disulfide-constrained peptides that antagonize binding of the VEGF dimer to its receptors, KDR and Flt-1, were identified previously using phage display methods. NMR studies of a representative peptide from the most potent class of these peptide antagonists, v107 (GGNECDAIRMWEWECFERL), were undertaken to characterize its interactions with VEGF. v107 has no defined structure free in solution, but binding to VEGF induces folding of the peptide. The solution structure of the VEGF receptor-binding domain-v107 complex was determined using 3940 (1970 per VEGF monomer) internuclear distance and 476 (238 per VEGF monomer) dihedral angle restraints derived from NMR data obtained using samples containing either (13)C/(15)N-labeled protein plus excess unlabeled peptide or (13)C/(15)N-labeled peptide plus excess unlabeled protein. Residual dipolar coupling restraints supplemented the structure determination of the complex and were found to increase significantly both the global precision of VEGF in the complex and the agreement with available crystal structures of VEGF. The calculated ensemble of structures is of high precision and is in excellent agreement with the experimental restraints. v107 has a turn-helix conformation with hydrophobic residues partitioned to one face of the peptide and polar or charged residues at the other face. Contacts between two v107 peptides and the VEGF dimer are mediated by primarily hydrophobic side-chain interactions. The v107-binding site on VEGF overlaps partially with the binding site of KDR and is similar to that for domain 2 of Flt-1. The structure of the VEGF-v107 complex provides new insight into how binding to VEGF can be achieved that may be useful for the design of small molecule antagonists.
J Mol Biol 2002 Feb 22
PMID:Solution structure of a phage-derived peptide antagonist in complex with vascular endothelial growth factor. 1186 30

Comparative analysis of the transcriptional profiles of approximately 6000 genes in the retinas of wild-type mice with those carrying a targeted disruption of the rhodopsin gene was undertaken by microarray analysis. This revealed a series of transcripts, of which some were derived from genes known to map at retinopathy loci, levels of which were reduced or elevated in the retinas of Rho(-/-) mice lacking functional photoreceptors. The human homologue of one of these genes, encoding inosine monophosphate dehydrogenase type 1 (IMPDH1), maps to the region of 7q to which an adRP gene (RP10) had previously been localized. Mutational screening of DNA from the Spanish adRP family, originally used to localize the RP10 gene, revealed an Arg224Pro substitution co-segregating with the disease phenotype. The amino acid at position 224 of the IMPDH1 protein is conserved among species and the substitution is not present in healthy, unrelated individuals of European origin. These data provide strong evidence that mutations within the IMPDH1 gene cause adRP, and validate approaches to mutation detection involving comparative analysis of global transcription profiles in normal and degenerating retinal tissues. Other genes showing significant alterations in expression include some with anti-apoptotic functions and many encoding components of the extracellular matrix or cytoskeleton, a possible reflection of a response by Muller cells to preserve the remaining outer nuclear layer of the retina. We suggest that those genes identified are prime candidates for etiological involvement in degenerative retinal disease.
Hum Mol Genet 2002 Mar 01
PMID:Identification of an IMPDH1 mutation in autosomal dominant retinitis pigmentosa (RP10) revealed following comparative microarray analysis of transcripts derived from retinas of wild-type and Rho(-/-) mice. 1187 49

Several inherited human neurological disorders can be caused by mutations in genes encoding Ca2+ channel subunits. This review deals with known human and mouse calcium channelopathies of the central nervous system (CNS). The human diseases comprise: 1) a recessive retinal disorder, X-linked congenital stationary night blindness, associated with mutations in the CACNA1F gene, encoding alpha(1)1.4 subunits of L-type channels; and 2) a group of rare allelic autosomal dominant human neurological disorders including familial hemiplegic migraine, episodic ataxia type 2, and spinocerebellar ataxia type 6, all associated with mutations in the CACNA1A gene, encoding alpha(1)2.1 subunits of P/Q-type calcium channels. Mutations at the mouse orthologue of the CACNA1A gene cause a group of recessive neurological disorders, including the tottering, leaner, and rocker phenotypes with ataxia and absence epilepsy, and the rolling Nagoya phenotype with ataxia without seizures. Two other spontaneous mouse mutants with ataxia and absence epilepsy, lethargic and stargazer, have mutations in genes encoding a calcium channel auxiliary beta subunit and a putative calcium channel auxiliary gamma subunit. For each channelopathy, the review describes disease phenotype, channel genotype, and known functional consequences of the pathological mutations; in some cases, it also describes working hypothesis and/or speculations addressing the challenging question of how the alterations in channel function lead to selective cellular dysfunction and disease.
Mol Neurobiol 2002 Feb
PMID:Calcium channels and channelopathies of the central nervous system. 1189 Apr 56

Complications of diabetes have a genetic influence. Since increased inducible nitric oxide synthase (iNOS) gene ( NOS2A) expression can contribute to tissue damage, NOS2A is a worthy candidate for such a role. We therefore tested a 4-bp insertion/deletion (+/-) polymorphism 0.7 kb upstream of NOS2A for association with complications in type 2 diabetes patients, and also performed transient transfection experiments to examine the effect of this variant on promoter activity in kidney cells in culture. We investigated 379 Caucasian type 2 diabetes patients of British/European descent, 93 of whom had microalbuminuria, 26 overt nephropathy, 46 retinopathy, and 73 clinical neuropathy. Genotyping for the variant was carried out by PCR and automated Genescan analysis. Transient transfection studies involved the renal HEK 293 cell line and luciferase reporter gene constructs containing 1.1 kb of 5'-flanking DNA from '+' or '-' allele homozygotes. We found that the '+' allele frequency in patients without microalbuminuria was 12%, but was 23% in those with microalbuminuria ( P=0.0005), and was 26% in those with nephropathy ( P=0.0007), 22% in those with retinopathy ( P=0.037), and 23% in those with neuropathy ( P=0.045). The odds ratios for homozygote +/+ to have microalbuminuria or nephropathy were 2.4 (95% CI 1.4-4.2, P=0.0023) and 5.4 (95% CI 1.8-16, P=0.0009), respectively. Luciferase reporter gene constructs containing 1 kb of NOS2A promoter DNA for each allele were made and sequence analysis confirmed that the +/- variation was the only sequence difference present. Transient transfection of these into HEK 293 cells revealed 25 times higher reporter gene activity for the '+' allele compared with the '-' allele. Gel shift analysis with 30mer oligonucleotides corresponding to each allele showed specific binding to nuclear extracts, being greater for the '+' allele. Thus the '+' allele of the NOS2A promoter variant may confer higher iNOS expression, and could contribute to complications of type 2 diabetes, especially in the approximately 5% of patients homozygous for this variant.
J Mol Med (Berl) 2002 Feb
PMID:Association of a functional inducible nitric oxide synthase promoter variant with complications in type 2 diabetes. 1190 46

We introduced a targeted single base deletion at codon 307 of the rds-peripherin gene in mice, similar mutations being known to cause autosomal dominant retinitis pigmentosa (RP) in man. Histopathological and electroretinographic analysis indicate that the retinopathy in mice homozygous for the codon 307 mutation appears more rapid than that in the naturally occurring null mutant, the rds(-/-) mouse, suggesting that the rds-307 mutation displays a dominant negative phenotype in combination with that due to haplosufficiency. RP is the most prevalent cause of registered visual handicap in those of working age in developed countries, the 50 or so mutations so far identified within the RDS-peripherin gene accounting for up to 10% of dominant cases of the disease. Given the sequence homologies that exist between the murine rds-peripherin and the human RDS-peripherin gene, this disease model, the first to be generated for peripherin-based RP using gene targeting techniques, should in principle be of value in the work-up in mice of therapeutics capable of targeting transcripts derived from the human gene.
Hum Mol Genet 2002 May 01
PMID:Murine model of autosomal dominant retinitis pigmentosa generated by targeted deletion at codon 307 of the rds-peripherin gene. 1197 60


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