Objective-Heme oxygenase-1 (HO-1) is an antioxidative, antiinflammatory, and cytoprotective enzyme that is induced in response to cellular stress. The HO-1 promoter contains a (GT)n microsatellite DNA, and the number of GT repeats can influence the occurrence of cardiovascular diseases. We elucidated the effect of this polymorphism on endothelial cells isolated from newborns of different genotypes. Methods and Results-On the basis of HO-1 expression, we classified the HO-1 promoter alleles into 3 groups: short (S) (most active, GT Յ23), medium (moderately active, GTϭ24 to 28), and long (least active, GT Ն29). The presence of the S allele led to higher basal HO-1 expression and stronger induction in response to cobalt protoporphyrin, prostaglandin-J 2 , hydrogen peroxide, and lipopolysaccharide. Cells carrying the S allele survived better under oxidative stress, a fact associated with the lower concentration of oxidized glutathione and more favorable oxidative status, as determined by measurement of the ratio of glutathione to oxidized glutathione. Moreover, they proliferated more efficiently in response to vascular endothelial growth factor A, although the vascular endothelial growth factor-induced migration and sprouting of capillaries were not influenced. Finally, the presence of the S allele was associated with lower production of some proinflammatory mediators, such as interleukin-1, interleukin-6, and soluble intercellular adhesion molecule-1. Conclusion-The
Heme oxygenase-1 (HO-1) has been demonstrated to play an important role in the regulation of signaling systems, which are involved in the control of cell cycle progression and apoptosis. Recently, a (GT)n dinucleotide repeat polymorphism in the HO-1 promoter was shown to modulate HO-1 gene expression. Short (<25 GT) repeats are associated with an increased HO-1 upregulation after stimulation than are longer repeats. Malignant melanoma (MM) is the most serious cutaneous malignancy with high tendency to aggressive growth and resistance to apoptosis. Therefore, we sought to study the influence of this polymorphism on the progression of MM. We determined the HO-1 promoter genotype in 152 patients with MM and 398 healthy controls and studied their association in regard to susceptibility to MM, Breslow thickness and disease-free survival. In our study, the homozygous short allele with <25 (GT)n repeats (S/S) was found more frequently in the melanoma group compared to the healthy control population (21 and 12%, respectively). The calculated risk for acquiring primary MM in S/S carriers was 2-fold higher compared to those with L-allele types (95% confidence interval: 1.2-2.4, p 5 0.03). Additionally, the S/S genotype was significantly associated with primary tumors with deeper Breslow thickness compared to L-allele (>25 repeats) carriers (mean Breslow thickness: 4.0 6 2.9 mm versus 3.1 6 1.7 mm, p 5 0.03). These data suggest that HO-1 might render a higher risk for MM in S/S genotype individuals and could represent an important candidate gene in the pathogenesis and growth of malignant melanoma. ' 2006 Wiley-Liss, Inc.
BackgroundCerebral malaria (CM) represents a severe outcome of the Plasmodium falciparum infection. Recent genetic studies have correlated human genes with severe malaria susceptibility, but there is little data on genetic variants that increase the risk of developing specific malaria clinical complications. Nevertheless, susceptibility to experimental CM in the mouse has been linked to host genes including Transforming Growth Factor Beta 2 (TGFB2) and Heme oxygenase-1 (HMOX1). Here, we tested whether those genes were governing the risk of progressing to CM in patients with severe malaria syndromes.Methodology/Principal FindingsWe report that the clinical outcome of P. falciparum infection in a cohort of Angolan children (n = 430) correlated with nine TGFB2 SNPs that modify the risk of progression to CM as compared to other severe forms of malaria. This genetic effect was explained by two haplotypes harboring the CM-associated SNPs (Pcorrec. = 0.035 and 0.036). In addition, one HMOX1 haplotype composed of five CM-associated SNPs increased the risk of developing the CM syndrome (Pcorrec. = 0.002) and was under-transmitted to children with uncomplicated malaria (P = 0.036). Notably, the HMOX1-associated haplotype conferred increased HMOX1 mRNA expression in peripheral blood cells of CM patients (P = 0.012).Conclusions/SignificanceThese results represent the first report on CM genetic risk factors in Angolan children and suggest the novel hypothesis that genetic variants of the TGFB2 and HMOX1 genes may contribute to confer a specific risk of developing the CM syndrome in patients with severe P. falciparum malaria. This work may provide motivation for future studies aiming to replicate our findings in larger populations and to confirm a role for these genes in determining the clinical course of malaria.
Background: Epithelial sodium channel (ENaC)  and ␥ subunits are modified by Cys palmitoylation. Results: Palmitoylation of the ␥ subunit activates ENaCs by increasing channel open probability. Conclusion: ␥ subunit palmitoylation has a dominant role in activating ENaCs compared with  subunit palmitoylation. Significance: ENaC palmitoylation is an important post-translational mechanism of channel regulation.
We identified potentially causative mutations in the active protein S gene (PROS 1) by direct sequencing of PROS 1-specific polymerase chain reaction (PRC) products of all 15 exons, including exon-intron boundaries in 10 families with hereditary protein S deficiency type I. Seven different mutations were found in 9 of 10 families, including one frame shift mutation, a previously published splice site mutation (both occurring in two unrelated families), four missense mutations, and a stop codon at the beginning of exon 12. In family studies, cosegregation of the mutation with the disease could be demonstrated for five mutations; for two missense mutations, this was not possible due to limited family data. All seven mutations were the only abnormalities identified in the respective index patients and were absent in 44 to 62 normal individuals. Therefore, they most likely represent the causal gene defects. For five mutations, analysis of ectopic RNA could be performed. Mutant transcripts were present in the case of the frame shift and three of the missense mutations, while no mutant RNA could be detected in the case of the stop codon.
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