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1.
Quantification of the overall reactive oxygen species scavenging capacity of biological fluids and tissues 总被引:1,自引:0,他引:1
A method has been developed for measuring and evaluating the overall antioxidant activity derived from the low-molecular weight antioxidants (scavengers). The principle governing this method is based on a common chemical characteristic of the scavengers, their reducing properties. It was hypothesized and then demonstrated that an evaluation of the overall reducing power of a biological sample correlates with the overall scavenging activity of the sample. In order to quantify the total reducing power, the cyclic voltammetry methodology was applied. The resulting measurements correlated with the antioxidant activity of both hydrophilic and lipophilic scavengers. The method is suitable for use in biological fluids and in tissue homogenates, and can supply information concerning the type of antioxidants and their total concentration without having to determine specific compounds. A noninvasive procedure for determining skin overall scavenging activity is also described. This method is based on a well containing an extraction solution that is attached to the skin's surface. Following incubation time the extraction solution is analyzed using the cyclic voltammeter instrument and other methods. We have found these methods suitable for evaluating the reducing capacity status in various clinical conditions such as diabetes, ionizing and nonionizing irradiation, brain degenerative diseases, head trauma, and inflammatory bowel diseases. This method is also an efficient tool for evaluating the overall antioxidant capacity of mixtures of antioxidant preparations in vitro. The measurements themselves are simple and rapid. Furthermore, they do not require manipulation of the samples. 相似文献
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Arumugam Parthasarathy Venkatachalam Gopi Subramanian Umadevi Anoop Simna Mohammed Jainuddin Yousuf Sheik H. Divya Elangovan Vellaichamy 《Molecular and cellular biochemistry》2013,378(1-2):217-228
Cardiac hormone atrial natriuretic peptide (ANP) and its receptor natriuretic peptide receptor-A (NPR-A) system acts as an intrinsic negative regulator of abnormal extracellular matrix (ECM) remodeling in the heart. However, the underlying mechanism by which ANP/NPR-A system opposes the ECM remodeling in the diseased heart is not well understood. Here, we investigated the anti-fibrotic mechanism of ANP/NPR-A in fibrotic agonist Angiotensin- II (ANG II)-treated adult cardiac fibroblast (CF) cells. Normal and NPR-A-suppressed adult CF cells were treated with ANG II (10?7 M) in the presence and absence of ANP (10?8 M) for 24 h. Total collagen concentration, activity and expression of MMP-2 and MMP-9, and nuclear translocation of Nuclear factor-kappaB (NF-κB-p50) were studied. NPR-A-suppressed adult CF cells exhibited a more pronounced increase in collagen production, ROS generation, and NF-κB-p50 nuclear translocation as compared to adult CF cells treated with agonist alone. ANP co-treatment significantly reverses the agonist-induced above changes in normal adult CF cells, while it failed to reverse the agonist-induced collagen synthesis in the NPR-A-suppressed adult CF cells. The cGMP analog (8-bromo-cGMP) treatment significantly attenuated the agonist-induced collagen synthesis both in normal and NPR-A-suppressed adult cells. The results of this study suggest that ANP/NPR-A signaling system antagonizes the agonist-induced collagen synthesis via suppressing the activities of MMP-2, MMP-9, ROS generation, and NF-κB nuclear translocation mechanism. 相似文献
3.
Lakshmi Priya Kalaiarasu Vimala Subramanian Boopathi Sowndharrajan Elangovan Vellaichamy 《International journal of peptide research and therapeutics》2016,22(4):451-463
We sought to determine the in vivo anti-inflammatory activity of atrial natriuretic peptide (ANP) using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced acute and chronic skin inflammatory mice model. ANP treatment (2 μg/kg body weight/day/i.p. for acute and 0.5 μg/kg body weight/day/i.p. for chronic inflammatory study) was started after 30 min of TPA application. The standard drug, aspirin (ASP) (20 μg/kg body weight/day/i.p.; 10 μg/kg body weight/day/i.p., respectively) was used as a positive control for the both acute and chronic study. TPA alone treated mice exhibited a marked increase in the ear length (7 ± 0.08 vs. 13 ± 0.7 mm, p < 0.001) as well as in ear weight (80 ± 1.3 vs. 130 ± 1.5 mg, p < 0.001) as compared with control mice. Upon treatment with ANP, the increased ear length and weight were reverted back to near normal level. Similarly, ANP treatment markedly suppressed the TPA-induced chronic skin inflammatory lesion (5.7 ± 0.2 vs. 0.95 ± 0.05, p < 0.001) as compared with TPA-induced mouse skin. TPA-induced alterations in the levels of serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), total white blood cell (TWBC), serum tumor necrosis factor-α (TNF-α), natriuretic peptide receptor-A (NPR-A), cyclooxygenase-2 (COX-2), matrix metalloproteinase-2/-9 (MMP-2/-9) and nuclear factor kappa B (NF-κB) (p < 0.01, respectively) were reverted back to near normal levels. The results of the present study clearly show the in vivo anti-inflammatory activity of ANP, which is comparable with that of a standard drug, ASP. Our results suggest that ANP elicits its anti-inflammatory activity by down-regulating the expressions of NPR-A, COX-2, MMPs and NF-κB. 相似文献
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Ubiquitination is an important post-translational event responsible for half-life and turnover of proteins inside the cell. Proteins are ubiquitinated by forming an iso-peptide bond between their lysine residue and C-terminal glycine residue of ubiquitin leading to rapid degradation of proteins by 26S proteosome complex. Deregulation of ubiquitination is manifested by aberrant expression of E3-ligase activity or mutation in the surroundings of ubiquitination sites. Many new experimentally validated ubiquitinated lysines have been recently identified that motivated the study of the environments surrounding the ubiquitinated lysines. With the help of known ubiquitinated proteins, here we present a comprehensive study of sequence and spatial environment of ubiquitination sites of human and yeast proteins. To identify position-specific features, this work distinguishes the spatial environments as proximity and distal regions. Certain amino acids specific to these regions, well differentiate the ubiquitination sites from non-ubiquitination sites are revealed. Additionally, amino acid signatures that contribute for protein disordered regions and solvent accessibility of amino acids are found to be contributing factors in ubiquitination sites. These results suggest that the ubiquitination site environment of the substrate determines the recognition and unfolding of substrate to facilitate the entry into 26S proteosomal complex. We believe that these findings will help in better prediction of ubiquitination sites using the sequence and spatial information. 相似文献
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Gopi Krishnan Gopala Krishnan Aiswarya Sethumadhavan Pavithra Vellaichamy Maheswaran Mani 《Microbiology and immunology》2019,63(6):229-237
Pseudomonas aeruginosa is a major cause of nosocomial infections and contributes to higher mortality in hospitalized individuals. Infection by P. aeruginosa triggers host immune response through activation of pathogen recognition receptors, which are present in innate cells. Several studies have reported the mechanism of P. aeruginosa induced innate immunity in multiple cell types. But so far there is no reports on response of megakaryocytes to P. aeruginosa infection. Hence, our aim was to investigate the precise role and signaling mechanism of megakaryocytes during P. aeruginosa infection. In this study, we used Mo7e cells as representatives of human megakaryocyte and found that P. aeruginosa infection induces cytotoxicity in these cells. We further demonstrated that P. aeruginosa infection modulates p38 and extracellular signal regulated kinase pathways in Mo7e cells. Protein expression profiling in P. aeruginosa lipopolysaccharide‐treated Mo7e cells revealed upregulation of importin subunit β and downregulation of metabolic enzymes. Our results suggest that P. aeruginosa infection regulates mitogen‐activated protein kinases signaling pathway and importin in Mo7e cells and that this is a potential mechanism for nuclear translocation of nuclear factor binding near the κ light‐chain gene in B cells and c‐Jun N‐terminal kinases to induce cell cytotoxicity. 相似文献
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Vellaichamy E Sommana NK Pandey KN 《Biochemical and biophysical research communications》2005,327(1):106-111
Mice lacking natriuretic peptide receptor-A (NPRA) develop progressive cardiac hypertrophy and congestive heart failure. However, the mechanisms responsible for cardiac hypertrophic growth in the absence of NPRA signaling are not yet known. We sought to determine the activation of nuclear factor-kappaB (NF-kappaB) in Npr1 (coding for NPRA) gene-knockout (Npr1-/-) mice exhibiting cardiac hypertrophy and fibrosis. NF-kappaB binding activity was 4-fold greater in the nuclear extract of Npr1-/- mutant mice hearts as compared with wild-type (Npr1+/+) mice hearts. In parallel, inhibitory kappaB kinase-beta activity and IkappaB-alpha protein phosphorylation were also increased 3- and 4-fold, respectively, in hypertrophied hearts of mutant mice. cGMP levels were significantly reduced 5-fold in plasma and 10-fold in ventricular tissues of mutant mice hearts relative to wild-type controls. The present findings provide direct evidence that ablation of NPRA/cGMP signaling activates NF-kappaB binding activity associated with hypertrophic growth of mutant mice hearts. 相似文献
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G. Nagaraj A. Sukumar B. Nandlal S. Vellaichamy K. Thanasekaran A. L. Ramanathan 《Biological trace element research》2009,131(3):255-262
Element contents of teeth elucidate exposure nature, but less is known about association of tooth element concentrations of
diabetics and hypertensives with exposure profile. Present study aims to estimate copper, chromium, iron, zinc, nickel, and
lead concentrations in the permanent teeth of control, diabetic, and hypertensive subjects from Mysore. The results show that
lead levels of teeth (Pb-T) are higher in the hypertensives and diabetics, whereas copper levels of teeth (Cu-T) are lower
in the hypertensives and users of stainless steel utensils than that of controls and users of mixed utensils. The elevated
Cu-T levels found in the users of mixed utensils that being made of several metals are ascribed to leaching effect of sour
and spicy food of Indian cuisine. The element levels were influenced by diet (Zn-T), place of living, sex and income (Pb-T)
of the subjects, but not by age, drinking water from different sources, and certain habits viz., smoking, alcohol consumption,
chewing betel, and nut. Thus, it is evident that high Pb-T and low Cu-T levels may be related with diabetes and hypertension
and high Pb-T and Cu-T levels, respectively, in the urbanites, and the users of mixed utensils may show different exposure
profiles from environment and utensils. 相似文献
10.
Adaikkalam Vellaichamy Zoltán Dezs? Lellean JeBailey Arul M. Chinnaiyan Arun Sreekumar Alexey I. Nesvizhskii Gilbert S. Omenn Andrej Bugrim 《PloS one》2010,5(6)