38585383
Cloning of the human cholesteryl ester hydrolase promoter: identification of functional peroxisomal proliferator-activated receptor responsive elements.
Cholesteryl ester hydrolase (CEH) is responsible for hydrolysis of stored cholesterol esters in macrophage foam cells and release of free cholesterol for high-density lipoprotein-mediated efflux. PCR-based screening of human genomic libraries with human macrophage CEH specific primers resulted in amplification and cloning of 1.7 kb promoter sequence. Analysis of the sequence revealed a lack of consensus TATA-box but presence of a GC-rich proximal sequence, a CAAT box and several binding sites for the transcription factor Sp1. Three putative response elements for peroxisome proliferator-activated receptor (PPRE) were identified at position -176, -779, and -1316. Down-regulation of promoter activity was observed in the presence of either PPARalpha- or PPARgamma-specific ligands and introduction of a 4-point transverse mutation in the PPRE at -176 completely abolished the effect of PPAR ligands on the promoter activity. Analogous to other genes involved in macrophage cholesterol homeostasis, human CEH may also be regulated by PPAR.
46480527
Macrophage cholesterol homeostasis and metabolic diseases: critical role of cholesteryl ester mobilization
Atherogenic dyslipidemia, including low HDL levels, is the major contributor of residual risk of cardiovascular disease that remains even after aggressive statin therapy to reduce LDL-cholesterol. Currently, distinction is not made between HDL-cholesterol and HDL, which is a lipoprotein consisting of several proteins and a core containing cholesteryl esters (CEs). The importance of assessing HDL functionality, specifically its role in facilitating cholesterol efflux from foam cells, is relevant to atherogenesis. Since HDLs can only remove unesterified cholesterol from macrophages while cholesterol is stored as CEs within foam cells, intracellular CE hydrolysis by CE hydrolase is vital. Reduction in macrophage lipid burden not only attenuates atherosclerosis but also reduces inflammation and linked pathologies such as Type 2 diabetes and chronic kidney disease. Targeting reduction in macrophage CE levels and focusing on enhancing cholesterol flux from peripheral tissues to liver for final elimination is proposed.
25354783
Molecular cloning and expression of rat hepatic neutral cholesteryl ester hydrolase.
The 1923 bp cDNA for rat hepatic cholesteryl ester hydrolase (CEH) was cloned by screening a lambda gt11 expression library with an oligonucleotide containing the consensus active site sequence for cholesteryl esterases. Expression of a fusion protein, cross-reacting with antibody to the purified liver CEH, was demonstrated by Western blot analysis. The cDNA was sequenced and found to have only 44% homology with pancreatic CEH. Although unique, the cDNA sequence exhibited much greater overall homology with liver carboxylesterases, in both coding and 5'/3' non-coding regions. In Northern blot analysis, the cDNA hybridized with a single band from liver mRNA but not with pancreatic mRNA. The 1.7 kb coding sequence, predicting a 62 kDa protein, was cloned into an Escherichia coli expression system with an inducible promoter and into COS-7 cells. Both expression systems produced a protein which comigrated with liver CEH (66 kDa) on SDS-PAGE and immunoreacted with antibodies to liver CEH on Western blots. Whereas the prokaryotic system produced an inactive protein, expression in COS-7 cells was accompanied by a 5-fold increase in CEH activity and a corresponding increase in immunoreactive protein.
11257195
A quantile-based method for association mapping of quantitative phenotypes: an application to rheumatoid arthritis phenotypes
Genetic association of population-based quantitative trait data has traditionally been analyzed using analysis of variance (ANOVA). However, violations of certain statistical assumptions may lead to false-positive association results. In this study, we have explored model-free alternatives to ANOVA using correlations between allele frequencies in the different quantile intervals of the quantitative trait and the quantile values. We performed genome-wide association scans on anti-cyclic citrullinated peptide and rheumatoid factor-immunoglobulin M, two quantitative traits correlated with rheumatoid arthritis, using the data provided in Genetic Analysis Workshop 16. Both the quantitative traits exhibited significant evidence of association on Chromosome 6, although not in the human leukocyte antigen region which is known to harbor a major gene predisposing to rheumatoid arthritis. We found that while a majority of the significant findings using the asymptotic thresholds of ANOVA was not validated using permutations, a relatively higher proportion of the significant findings using the asymptotic cut-offs of the correlation statistic were validated using permutations.
30335490
Evaluation of Registered Visually Disabled Individuals in a District of West Bengal, India
Objective: To identify the sociodemographic characteristics, degree and cause of visual disability among certified visually disabled individuals in a rural district of West Bengal, India and to identify possible lacunae, if any, in the existing certification system. Materials and Methods: A cross-sectional study by secondary data analysis of medical records of 155 visually disabled individuals and their 310 eyes. Demographical features, diagnosis, percentage of visual disability and work activity status of each individual were analyzed. Results: One hundred and thirty one (84.52%) individuals had 100% disability. The number of males was significantly higher than that of females. Fifty eight (37.42%) individuals were below 21 years of age. Phthisis bulbi was the most common cause followed by microphthalmos. Further, 81.29% patients had the same lesion bilaterally. Conclusion: Patients with higher grades of disability have attended certification boards. A large number of disabled individuals comprised children and young adults. Male gender bias demands concern.
12243541
Cell density-dependent transcriptional activation of endocrine-related genes in human adipose tissue-derived stem cells.
Adipose tissue is recognized as an endocrine organ that plays an important role in human diseases such as type II diabetes and cancer. Human adipose tissue-derived stem cells (ASCs), a distinct cell population in adipose tissue, are capable of differentiating into multiple lineages including adipogenesis. When cultured in vitro under a confluent condition, ASCs reach a commitment stage for adipogenesis, which can be further induced into terminally differentiated adipocytes by a cocktail of adipogenic factors. Here we report that the confluent state of ASCs triggers transcriptional activation cascades for genes that are responsible for the endocrine function of adipose tissue. These include insulin-like growth factor 1 (IGF-1) and aromatase (Cyp19), a key enzyme in estrogen biosynthesis. Despite similar adipogenic potentials, ASCs from different individuals display huge variations in activation of these endocrine-related genes. Bioinformatics and experimental data suggest that transcription factor Foxo1 controls a large number of "early" confluency-response genes, which subsequently induce "late" response genes. Furthermore, siRNA-mediated knockdown of Foxo1 substantially compromises the ability of committed ASCs to stimulate tumor cell migration in vitro. Thus, our work suggests that cell density is an important determinant of the endocrine potential of ASCs.
6513668
A Role of CREB in BRCA1 Constitutive Promoter Activity and Aromatase Basal Expression
Aromatase is the rate-limiting enzyme in estrogen biosynthesis and a key target in breast cancer treatment. Its ovary-specific promoter, pII, is induced in response to protein kinase A (PKA) activation. It has been proposed that breast cancer susceptibility gene 1, BRCA1, is involved in negative regulation of aromatase pII activity. Surprisingly, inhibition of PKA pathway by inhibitor H89 elevates basal aromatase expression while abolishes cAMP-mediated aromatase induction in an ovarian granulosa cell line, KGN. In this report, we decipher the mechanism by which the PKA pathway negatively regulates aromatase basal expression. We show that PKA pathway plays a positive role in the expression of BRCA1. H89 effectively reduces endogenous BRCA1 mRNA levels as well as reporter gene expression from a BRCA1 promoter. Mutation of a cAMP-responsive element (CRE) in the BRCA1 promoter reduces BRCA1 expression. Chromatin immunoprecipitation (ChIP) shows that CRE-binding protein, CREB, binds to the BRCA1 promoter. Furthermore, knockdown of CREB in KGN cells leads to decreased BRCA1 level as well as elevated basal aromatase mRNA expression. These data demonstrate that both the CRE site in the BRCA1 promoter and CREB are required for BRCA1 constitutive expression. Our study suggests that PKA pathway exerts its negative impact on basal aromatase expression indirectly by contributing to the constitutive expression of BRCA1.
20902543
Fatal Morganella morganii bacteraemia in a diabetic patient with gas gangrene.
We report a case of a 60-year-old lady with a history of a heel ulcer that had not responded to antibiotic therapy. This progressed to involve the right leg, which was swollen and erythematous. Radiological imaging revealed the presence of gas within the fascial planes. Blood cultures on admission yielded Morganella morganii. Due to the extent of the gas gangrene and her co-morbidities the patient was not suitable for surgical intervention and was treated conservatively with antibiotics. She deteriorated and died within 72 h of presentation. Non-clostridial gas gangrene is relatively rare, and diagnosis is frequently delayed and often missed. Early aggressive surgical intervention combined with appropriate antibiotic therapy is essential. Bacterial species other than Clostridium should be considered in all cases of gas gangrene.