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21.
Ascorbic acid treatment in arsenic trioxide treated rats increased arsenic excretion, inhibited lipid peroxidation, improved GSH status, regulated GSSG turnover and also restored glutathione-S-transferases activity in liver and kidney. Suitable mechanisms leading to ascorbic acid protection have been discussed. Upregulation of GSH dependent enzymes was found to be necessary for a protective effect. Protection is finally attributed to higher GSH levels observed in the liver and kidney of ascorbic acid and inorganic arsenic treated rats. It is also concluded that ascorbic acid protection is influenced by gender dependent factors. Arsenic poisoning is a global problem now. Gender differences need to be considered while applying therapeutic measures. 相似文献
22.
Pramanik A Mitra A Arumugam M Bhattacharyya A Sadhukhan S Ray A Haldar S Mukhopadhyay UK Mukherjee J 《Folia microbiologica》2012,57(1):71-79
Vinasse, a recalcitrant waste of the ethanol industry was employed for the production of polyhydroxyalkanoate (PHA) by the
extremely halophilic archaeon, Haloarcula marismortui in shake flasks. The PHA was recovered by osmotic lysis of the cells and subsequent purification by sodium hypochlorite and
organic solvents. Through UV–vis spectroscopy, differential scanning calorimetry, Fourier transform infrared, and nuclear
magnetic resonance spectroscopy, the PHA was found to have characteristics very similar to that of the standard polyhydroxybutyrate
(PHB) from Sigma. Inhibitory effect of polyphenols contained in vinasse was assessed by a quick and reliable cup-plate agar-diffusion
method. Raw vinasse (10%) was utilized leading to accumulation of 23% PHA (of cell dry weight) and following an efficacious
pre-treatment process through adsorption on activated carbon, 100% pre-treated vinasse could be utilized leading to 30% accumulation
of PHB by H. marismortui. Maximum specific growth rate, specific production rate, and volumetric productivity attained using 10% raw vinasse were
comparable to that obtained using a previously reported nutrient deficient medium (NDM), while the values with 100% pre-treated
vinasse were higher than that determined using NDM medium. This is the first report of polyhydroxybutyrate production by a
halophilic microorganism utilizing vinasse. 相似文献
23.
24.
Amanda M Casto Jun Z Li Devin Absher Richard Myers Sohini Ramachandran Marcus W Feldman 《Genome biology》2010,11(1):R10
Background
The transmission pattern of the human X chromosome reduces its population size relative to the autosomes, subjects it to disproportionate influence by female demography, and leaves X-linked mutations exposed to selection in males. As a result, the analysis of X-linked genomic variation can provide insights into the influence of demography and selection on the human genome. Here we characterize the genomic variation represented by 16,297 X-linked SNPs genotyped in the CEPH human genome diversity project samples. 相似文献25.
Sohini Mukherjee Carrie L. Partch Rebecca E. Lehotzky Cecilia V. Whitham Hiutung Chu Charles L. Bevins Kevin H. Gardner Lora V. Hooper 《The Journal of biological chemistry》2009,284(8):4881-4888
Members of the RegIII family of intestinal C-type lectins are directly
antibacterial proteins that play a vital role in maintaining host-bacterial
homeostasis in the mammalian gut, yet little is known about the mechanisms
that regulate their biological activity. Here we show that the antibacterial
activities of mouse RegIIIγ and its human ortholog, HIP/PAP, are tightly
controlled by an inhibitory N-terminal prosegment that is removed by trypsin
in vivo. NMR spectroscopy revealed a high degree of conformational
flexibility in the HIP/PAP inhibitory prosegment, and mutation of either
acidic prosegment residues or basic core protein residues disrupted prosegment
inhibitory activity. NMR analyses of pro-HIP/PAP variants revealed distinctive
colinear backbone amide chemical shift changes that correlated with
antibacterial activity, suggesting that prosegment-HIP/PAP interactions are
linked to a two-state conformational switch between biologically active and
inactive protein states. These findings reveal a novel regulatory mechanism
governing C-type lectin biological function and yield new insight into the
control of intestinal innate immunity.The gastrointestinal tracts of mammals are heavily colonized with vast
symbiotic microbial communities and are also a major portal of entry for
bacterial pathogens. To cope with these complex microbial challenges,
intestinal epithelial cells produce a diverse repertoire of protein
antibiotics from multiple distinct protein families
(1). These proteins are
secreted apically into the luminal environment of the intestine where they
play a pivotal role in protecting against enteric infections
(2,
3) and may also function to
limit opportunistic invasion by symbiotic bacteria
(4).We previously identified lectins as a novel class of secreted antibacterial
proteins in the mammalian intestine. RegIIIγ is a member of the RegIII
subgroup of the C-type lectin family and is expressed in the small intestine
in response to microbial cues
(5), stored in epithelial cell
secretory granules, and released into the small intestinal lumen
(5). Similarly, HIP/PAP
(hepatointestinal pancreatic/pancreatitis-associated protein; the human
ortholog of
RegIIIγ)6 is
expressed in the human intestine
(6) and is up-regulated in
patients with inflammatory bowel disease
(7). These proteins are
produced in multiple epithelial lineages, including enterocytes and Paneth
cells (5,
6). Both RegIIIγ and
HIP/PAP are directly bactericidal at low micromolar concentrations for
Gram-positive bacteria (5),
revealing a previously unappreciated biological function for mammalian
lectins. The antibacterial functions of RegIIIγ and HIP/PAP are
dependent upon binding bacterial targets through interactions with
peptidoglycan (5). As
peptidoglycan is localized on surfaces of Gram-positive bacteria but is buried
in the periplasmic space of Gram-negative bacteria, this binding activity
provides a molecular explanation for the Gram-positive specific bactericidal
effects of these lectins. Although the mechanism of lectin-mediated
antibacterial activity remains unclear, RegIIIγ and HIP/PAP have been
shown to elicit extensive damage to the cell surfaces of targeted bacteria
(5).In this study, we show that C-type lectin bactericidal activity is under
stringent post-translational control. RegIIIγ and HIP/PAP each undergo
in vivo proteolytic removal of a flexible anionic N-terminal
prosegment that maintains the proteins in a biologically inactive state. NMR
spectroscopy suggests that the prosegment functions by controlling a two-state
conformational switch between the biologically active and inactive states of
the protein. We propose that this regulatory mechanism allows the host to
restrict expression of RegIII lectin antibacterial activity to the intestinal
lumen. Together, our findings represent a unique example of post-translational
control of C-type lectin biological activity, and provide novel insight into
the regulation of lectin-mediated innate immunity in the mammalian
intestine. 相似文献
26.
The geographic distribution of genetic variation reflects trends in past population migrations and can be used to make inferences about these migrations. It has been proposed that the east-west orientation of the Eurasian landmass facilitated the rapid spread of ancient technological innovations across Eurasia, while the north-south orientation of the Americas led to a slower diffusion of technology there. If the diffusion of technology was accompanied by gene flow, then this hypothesis predicts that genetic differentiation in the Americas along lines of longitude will be greater than that in Eurasia along lines of latitude. We use 678 microsatellite loci from 68 indigenous populations in Eurasia and the Americas to investigate the spatial axes that underlie population-genetic variation. We find that genetic differentiation increases more rapidly along lines of longitude in the Americas than along lines of latitude in Eurasia. Distance along lines of latitude explains a sizeable portion of genetic distance in Eurasia, whereas distance along lines of longitude does not explain a large proportion of Eurasian genetic variation. Genetic differentiation in the Americas occurs along both latitudinal and longitudinal axes and has a greater magnitude than corresponding differentiation in Eurasia, even when adjusting for the lower level of genetic variation in the American populations. These results support the view that continental orientation has influenced migration patterns and has played an important role in determining both the structure of human genetic variation and the distribution and spread of cultural traits. 相似文献
27.
Sohini Kar 《The journal of the Royal Anthropological Institute》2017,23(2):302-319
With the growth of commercial microfinance in India, the poor have been increasingly enfolded into circuits of global finance. In making these collateral‐free loans, however, microfinance institutions (MFIs) engage in new forms of risk management. While loans are made to women with the goal of economic and social empowerment, MFIs require male kin to serve as guarantors. Drawing on fieldwork in the city of Kolkata, I argue that through the requirement of male guarantors, MFIs hedge on kinship, even as they speculate on the bottom of the pyramid as a new market of accumulation. 相似文献
28.
Elmore LW Norris MW Sircar S Bright AT McChesney PA Winn RN Holt SE 《Experimental biology and medicine (Maywood, N.J.)》2008,233(8):958-967
Telomerase plays a primary role in the maintenance of telomeres in immortal, germ, and tumor cells in humans but is lacking in most somatic cells and tissues. However, many species, including fish and inbred mice, express telomerase in most cells and tissues. Little is known about the expression of telomerase in aquatic species, although the importance of telomerase for longevity has been suggested. We compared telomerase activity and telomere lengths among a broad range of tissues from aquatic species and found telomerase at significant levels in both long- and short-lived aquatic species, suggesting constitutive telomerase expression has an alternative function. Telomere lengths in these aquatic species were comparable to those observed in normal human tissues and cell strains. Given that a host of aquatic species with short life spans have telomerase and a tremendous capacity to regenerate, we tested the hypothesis that telomerase upregulation is important for tissue regeneration. During regeneration, telomerase activity was upregulated and telomere lengths are maintained with the shortest telomeres being elongated, indicating the importance for maintaining telomere length and integrity during tissue regeneration. Thus, the expression of telomerase in aquatic animals is likely not related to longevity but to their ability to regenerate injured tissue. 相似文献
29.
Chosed R Tomchick DR Brautigam CA Mukherjee S Negi VS Machius M Orth K 《The Journal of biological chemistry》2007,282(9):6773-6782
XopD (Xanthomonas outer protein D), a type III secreted effector from Xanthomonas campestris pv. vesicatoria, is a desumoylating enzyme with strict specificity for its plant small ubiquitin-like modifier (SUMO) substrates. Based on SUMO sequence alignments and peptidase assays with various plant, yeast, and mammalian SUMOs, we identified residues in SUMO that contribute to XopD/SUMO recognition. Further predictions regarding the enzyme/substrate specificity were made by solving the XopD crystal structure. By incorporating structural information with sequence alignments and enzyme assays, we were able to elucidate determinants of the rigid SUMO specificity exhibited by the Xanthomonas virulence factor XopD. 相似文献
30.
Sohini Mazumdar Lisa M. Arendt Sarah Phillips Maja Sedic Charlotte Kuperwasser Grace Gill 《PloS one》2015,10(3)
Regulators of chromatin structure and gene expression contribute to tumor formation and progression. The co-repressor CoREST1 regulates the localization and activity of associated histone modifying enzymes including lysine specific demethylase 1 (LSD1) and histone deacetylase 1 (HDAC1). Although several CoREST1 associated proteins have been reported to enhance breast cancer progression, the role of CoREST1 in breast cancer is currently unclear. Here we report that knockdown of CoREST1 in the basal-type breast cancer cell line, MDA-MB-231, led to significantly reduced incidence and diminished size of tumors compared to controls in mouse xenograft studies. Notably, CoREST1-depleted cells gave rise to tumors with a marked decrease in angiogenesis. CoREST1 knockdown led to a decrease in secreted angiogenic and inflammatory factors, and mRNA analysis suggests that CoREST1 promotes expression of genes related to angiogenesis and inflammation including VEGF-A and CCL2. CoREST1 knockdown decreased the ability of MDA-MB-231 conditioned media to promote endothelial cell tube formation and migration. Further, tumors derived from CoREST1-depleted cells had reduced macrophage infiltration and the secretome of CoREST1 knockdown cells was deficient in promoting macrophage migration and macrophage-mediated angiogenesis. Taken together, these findings reveal that the epigenetic regulator CoREST1 promotes tumorigenesis in a breast cancer model at least in part through regulation of gene expression patterns in tumor cells that have profound non-cell autonomous effects on endothelial and inflammatory cells in the tumor microenvironment. 相似文献