The essential requirement of an animal heme peroxidase protein during the wing maturation process in Drosophila.

BACKGROUND: Thus far, a handful of genes have been shown to be related to the wing maturation process in insects. A novel heme peroxidase enzyme known as curly suppressor (Cysu)(formerly CG5873), have been characterized in this report because it is involved in wing morphogenesis. Using bioinformatics tools we found that Cysu is remarkably conserved in the genus Drosophila (>95%) as well as in invertebrates (>70%), although its vertebrate orthologs show poor homology. Time-lapse imaging and histochemical analyses have confirmed that the defective wing phenotype of Cysu is not a result of any underlying cellular alterations; instead, its wings fail to expand in mature adults. RESULTS: The precise requirement of Cysu in wings was established by identifying a bona fide mutant of Cysu from the Bloomington Drosophila Stock Centre collection. Its requirement in the wing has also been shown by RNA knockdown of the gene. Subsequent transgenic rescue of the mutant wing phenotype with the wild-type gene confirmed the phenotype resulting from Cysu mutant. With appropriate GAL4 driver like engrailed-GAL4, the Cysu phenotype was compartmentalized, which raises a strong possibility that Cysu is not localized in the extracellular matrix (ECM); hence, Cysu is not engaged in bonding the dorsal and ventral cuticular layers. Finally, shortened lifespan of the Cysu mutant suggests it is functionally essential for other biological processes as well. CONCLUSION: Cysu, a peroxinectin-like gene, is required during the wing maturation process in Drosophila because as a heme peroxidase, Cysu is capable of utilizing H2O2, which plays an essential role in post-eclosion wing morphogenesis.

A Study of salt and fat Consumption pattern in Regional Indian diet among hypertensive and dyslipidemic PaTients - SCRIPT study.

BACKGROUND: Cardiovascular diseases are leading cause of mortality and morbidity. There is an increasing prevalence of hypertension and dyslipidemia due to globalization and adoption of westernized dietary habits in India. These transitions are manifest in dietary patterns and health outcomes. OBJECTIVE: To study the dietary salt and fat intake among patients diagnosed with hypertension and dyslipidemia in India. METHODS: SCRIPT study was a pilot exploratory, cross-sectional, observational, descriptive, multi-center study. It was conducted across hospitals and clinics in five metro cities of India, represented into four regional zones. In each region (North, n = 113; East, n = 98; West, n = 83; South, n = 152), patients diagnosed with hypertension and dyslipidemia were enrolled in the study. Socio-demographic and treatment details were recorded. Participants were interviewed by a dietician and their dietary intake was assessed by a three-day recall of food item questionnaire/ food diary. RESULTS: Overall the mean total daily salt consumption was 10.9 grams. Region-wise, the mean daily salt consumption in North, East, West and South were 14.13, 9.81, 10.12 and 9.38 grams respectively. The daily salt consumption in the North was significantly higher than other regions (P=0.012). The daily consumption of saturated fats (total saturated fat, ghee and butter) in the North was higher and statistically significantly in comparison to West, South and East (P <0.05). Overall, fats contributed to 24.1%, proteins contributed to 12.7% and carbohydrate contributed to 63.2% of total energy per day. The percentage of fat and protein contributing to total energy per day was within the acceptable range. CONCLUSIONS: Our study documented higher dietary salt intake than that recommended in India. There is an urgent need to address the issue of high salt and saturated fat consumption. Nutritional strategies for reducing salt intake, saturated fat and balancing energy nutrients should be urgently applied in Indian hypertensive and dyslipidemia patients.

Technique for preprocessing of digital mammogram.

Digital mammogram has emerged as the most popular screening technique for early detection of breast cancer and other abnormalities in human breast tissue. It provides us opportunities to develop algorithms for computer aided detection (CAD). In this paper we have proposed three distinct steps. The initial step involves contrast enhancement by using the contrast limited adaptive histogram equalization (CLAHE) technique. Then define the rectangle to isolate the pectoral muscle from the region of interest (ROI) and finally suppress the pectoral muscle using our proposed modified seeded region growing (SRG) algorithm. The proposed algorithms were extensively applied on all the 322 mammogram images in MIAS database resulting in complete pectoral muscle suppression in most of the images. Our proposed algorithm is compared with other segmentation methods showing superior results in comparison.

A muscle-specific p38 MAPK/Mef2/MnSOD pathway regulates stress, motor function, and life span in Drosophila.

Molecular mechanisms that concordantly regulate stress, life span, and aging remain incompletely understood. Here, we demonstrate that in Drosophila, a p38 MAP kinase (p38K)/Mef2/MnSOD pathway is a coregulator of stress and life span. Hence, overexpression of p38K extends life span in a MnSOD-dependent manner, whereas inhibition of p38K causes early lethality and precipitates age-related motor dysfunction and stress sensitivity, that is rescued through muscle-restricted (but not neuronal) add-back of p38K. Additionally, mutations in p38K are associated with increased protein carbonylation and Nrf2-dependent transcription, while adversely affecting metabolic response to hypoxia. Mechanistically, p38K modulates expression of the mitochondrial MnSOD enzyme through the transcription factor Mef2, and predictably, perturbations in MnSOD modify p38K-dependent phenotypes. Thus, our results uncover a muscle-restricted p38K-Mef2-MnSOD signaling module that influences life span and stress, distinct from the insulin/JNK/FOXO pathway. We propose that potentiating p38K might be instrumental in restoring the mitochondrial detoxification machinery and combating stress-induced aging.

Identification of a new RTX-like gene cluster in Vibrio cholerae.

A gene cluster containing two genes in tandem has been identified in Vibrio cholerae ElTor N16961. Each has more than one cadherin domain and is homologous to the RTX toxin family and was common in various V. cholerae strains. Insertional mutagenesis demonstrated that each gene has a role in Hep-2 cell rounding, hemolytic activity towards human and sheep RBCs and biofilm formation. The mutants showed reduced adherence to intestinal epithelial cells as well as reduction of in vivo colonization in suckling mice. These two genes thus code for RTX-like toxins in V. cholerae and are associated with the pathogenecity of this organism.

Reduced mitochondrial SOD displays mortality characteristics reminiscent of natural aging.

Manganese superoxide dismutase (MnSOD or SOD2) is a key mitochondrial enzymatic antioxidant. Arguably the most striking phenotype associated with complete loss of SOD2 in flies and mice is shortened life span. To further explore the role of SOD2 in protecting animals from aging and age-associated pathology, we generated a unique collection of Drosophila mutants that progressively reduce SOD2 expression and function. Mitochondrial aconitase activity was substantially reduced in the Sod2 mutants, suggesting that SOD2 normally ensures the functional capacity of mitochondria. Flies with severe reductions in SOD2 expression exhibited accelerated senescence of olfactory behavior as well as precocious neurodegeneration and DNA strand breakage in neurons. Furthermore, life span was progressively shortened and age-dependent mortality was increased in conjunction with reduced SOD2 expression, while initial mortality and developmental viability were unaffected. Interestingly, life span and age-dependent mortality varied exponentially with SOD2 activity, indicating that there might normally be a surplus of this enzyme for protecting animals from premature death. Our data support a model in which disruption of the protective effects of SOD2 on mitochondria manifests as profound changes in behavioral and demographic aging as well as exacerbated age-related pathology in the nervous system.

Differential regulation of interchromosomal copies of ToxR-induced genes.

In Vibrio cholerae, ToxR transcriptionally activates a number of virulence genes in response to various environmental signals. In the present study, transcription profiling by macroarray was carried out with 13 pairs of genes, one copy of which is present in each chromosome under ToxR-inducing (pH 6.5, osmolarity 66 mmol/L, 30 degrees C) and ToxR-repressing (pH 8.5, osmolarity 300 mmol/L, 37 degrees C) conditions followed by high pH (8.5) and low pH (6.5) conditions to eliminate pH effect. The genes dacAII, tagEII, secDII, pmmI, pmmII, and immII showed increased expression in the ToxR-inducing conditions, but not at low pH, suggesting that the expression of these genes might be regulated by ToxR. The expression of pmmII, dacAII, tagEII, secDII, and immII genes decreased significantly in the toxR insertion mutant as determined by RT-PCR, whereas the expression of the chromosome I copy of pmm increased in toxR mutant compared with wild-type cells. Thus, the chromosome II copy of these genes, which show increased expression under ToxR-inducing conditions, are all regulated by ToxR in V. cholerae, whereas the chromosome I copy of pmm may be regulated by other factors under ToxR-inducing conditions.

In vivo induced clpB1 gene of Vibrio cholerae is involved in different stress responses and affects in vivo cholera toxin production.

Previously in global transcription profile approach one of the cosmid clones of Vibrio cholerae containing the genes pnuC, icmF, and a fragment of clpB2 showed higher expression in V. cholerae grown inside rabbit intestine. In the present report, both the stress responsive clpB genes of V. cholerae O395 were cloned, clpB1 from chromosome I and clpB2 present in chromosome II. From the Northern blot hybridization it was observed that the level of transcription of clpB2 was very low which could be due to the weak promoter strength of clpB2 as predicted in silico. The deduced amino acid sequence showed that clpB1 possesses features typical of the ClpB ATPase family of stress response proteins. The clpB1 gene showed about three times higher expression under in vivo condition than in vitro. Increased expression of clpB1 gene was also observed at high temperature, high salt, and in the condition mimicking human intestine viz., 37 degrees C, pH 8.5, 300 mM NaCl, which is known to be the repressive condition for ToxR, the global transcriptional regulator of virulence in V. cholerae. The clpB1 insertion mutant showed increased sensitivity towards high temperature, oxidative stress, and acid pH. ClpB1 also conferred thermotolerance to V. cholerae. These effects could be reversed by complementation. Although clpB1 appeared not to be under the control of virulence regulatory cascade of V. cholerae, the CT production was reduced in clpB1 mutant when tested in vivo in an infant mice model.

Involvement of in vivo induced cheY-4 gene of Vibrio cholerae in motility, early adherence to intestinal epithelial cells and regulation of virulence factors.

Using a global transcription profile approach cheY-4 of Vibrio cholerae was identified as an in vivo induced gene. In the present study, duplication of the gene in the chromosome resulted in increased motility, increased chemotactic response towards isolated intestinal mucus layer and stronger adhesion to human intestinal epithelial cell line at an early phase of infection compared to wild type and a null mutant strain. In contrast to the cheY-4 null mutant, duplication of cheY-4 gene resulted in increased expression of ctxAB and tcpA, the two major virulence genes of V. cholerae.