MRDG

High power lasers are used extensively in medicine while lower power applications are popular for optical imaging, optogenetics, skin rejuvenation and a therapeutic modality termed photobiomodulation (PBM). This study addresses the therapeutic dose limits, biological safety and molecular pathway of near-infrared (NIR) laser phototoxicity. Increased erythema and tissue damage were noted in mice skin and cytotoxicity in cell cultures at phototoxic laser doses involving generation of reactive oxygen species (ROS) coupled with a rise in surface temperature (>45 °C). NIR laser phototoxicity results from Activating Transcription Factor-4 (ATF-4) mediated endoplasmic reticulum stress and autophagy. Neutralizations of heat or ROS and overexpressing ATF-4 were noted to rescue NIR laser phototoxicity. Further, NIR laser mediated phototoxicity was noted to be non-genotoxic and non-mutagenic. This study outlines the mechanism of NIR laser phototoxicity and the utility of monitoring surface t...

Areca nut consumption has been implicated in the progression of Oral Submucous fibrosis (OSF); an inflammatory precancerous fibrotic condition. Our previous studies have demonstrated the activation of TGF-β signaling in epithelial cells by areca nut components and also propose a role for epithelial expressed TGF-β in the pathogenesis of OSF. Although the importance of epithelial cells in the manifestation of OSF has been proposed, the actual effectors are fibroblast cells. However, the role of areca nut and TGF-β in the context of fibroblast response has not been elucidated. Therefore, to understand their role in the context of fibroblast response in OSF pathogenesis, human gingival fibroblasts (hGF) were treated with areca nut and/or TGF-β followed by transcriptome profiling. The gene expression profile obtained was compared with the previously published transcriptome profiles of OSF tissues and areca nut treated epithelial cells. The analysis revealed regulation of 4666 and 1214 g...

Oral submucous fibrosis (OSF) is a chronic inflammatory disease characterized by the accumulation of excess collagen, and areca nut chewing has been proposed as an important etiological factor for disease manifestation. Activation of transforming growth factor-b signaling has been postulated as the main causative event for increased collagen production in OSF. Oral epithelium plays important roles in OSF, and arecoline has been shown to induce TGF-b in epithelial cells. In an attempt to understand the role of areca nut constituents in the manifestation of OSF, we studied the global gene expression profile in epithelial cells (HaCaT) following treatment with areca nut water extract or TGF-b. Interestingly, 64% of the differentially regulated genes by areca nut water extract matches with the TGF-b induced gene expression profile. Out of these, expression of 57% of genes was compromised in the presence of ALK5 (TbRI) inhibitor and 7% were independently induced by areca nut, highlighting the importance of TGF-b in areca nut actions. Areca nut water extract treatment induced p-SMAD2 and TGF-b downstream targets in HaCaT cells but not in human gingival fibroblast cells (hGF), suggesting epithelial cells could be the source of TGF-b in promoting OSF. Water extract of areca nut consists of polyphenols and alkaloids. Both polyphenol and alkaloid fractions of areca nut were able to induce TGF-b signaling and its downstream targets. Also, SMAD-2 was phosphorylated following treatment of HaCaT cells by Catechin, Tannin and alkaloids namely Arecoline, Arecaidine and Guvacine. Moreover, both polyphenols and alkaloids induced TGF-b2 and THBS1 (activator of latent TGF-b) in HaCaT cells suggesting areca nut mediated activation of p-SMAD2 involves up-regulation and activation of TGF-b. These data suggest a major causative role for TGF-b that is induced by areca nut in OSF progression.

Oxovanadium(iv) complexes of polypyridyl and curcumin-based ligands, viz. [VO(cur)(L)Cl] (, ) and [VO(scur)(L)Cl] (, ), where L is 1,10-phenanthroline (phen in and ), dipyrido[3,2-a:2',3'-c]phenazine (dppz in and ), Hcur is curcumin and Hscur is diglucosylcurcumin, were synthesized and characterized and their cellular uptake, photocytotoxicity, intracellular localization, DNA binding, and DNA photo-cleavage activity studied. Complex [VO(cur)(phen)Cl] () has V(IV)N2O3Cl distorted octahedral geometry as evidenced from its crystal structure. The sugar…

Exposure of oral cavity to areca nut is associated with several pathological conditions including oral submucous fibrosis (OSF). Histopathologically OSF is characterized by epithelial atrophy, chronic inflammation, juxtaepithelial hyalinization, leading to fibrosis of submucosal tissue and affects 0.5% of the population in the Indian subcontinent. As the molecular mechanisms leading to atrophied epithelium and fibrosis are poorly understood, we studied areca nut actions on human keratinocyte and gingival fibroblast cells. Areca nut water extract (ANW) was cytotoxic to epithelial cells and had a pro-proliferative effect on fibroblasts. This opposite effect of ANW on epithelial and fibroblast cells was intriguing but reflects the OSF histopathology such as epithelial atrophy and proliferation of fibroblasts. We demonstrate that the pro-proliferative effects of ANW on fibroblasts are dependent on insulin-like growth factor signalling while the cytotoxic effects on keratinocytes are dep...

The maintenance of immune tolerance requires the deletion of self-reactive T cells in the thymus. The expression of tissue-specific antigen genes (TSAs) by thymic epithelial cells is critical for this process and depends on the activity of the Autoimmune Regulator (Aire) protein, however, the molecular mechanism(s) Aire uses to target TSA gene loci are unknown. Here we identified two Aire-interacting proteins-activating transcription factor 7 interacting protein (ATF7ip) and methyl CpG binding protein 1 (MBD1)-that are required for Aire's targeting of TSA geneloci. Moreover, Mbd1 −/− mice developed pathological autoimmunity and had a defect in Airedependent thymic TSA gene expression underscoring the critical importance of Aire's interaction with the ATF7ip-MBD1 protein complex in maintaining central tolerance.

Autoimmune polyendocrine syndrome type 1 (APS1), a monogenic disorder caused by AIRE gene mutations, features multiple autoimmune disease components. Infertility is common in both males and females with APS1. Although female infertility can be explained by autoimmune ovarian failure, the mechanisms underlying male infertility have remained poorly understood. We performed a proteome-wide autoantibody screen in APS1 patient sera to assess the autoimmune response against the male reproductive organs. By screening human protein arrays with male and female patient sera and by selecting for gender-imbalanced autoantibody signals, we identified transglutaminase 4 (TGM4) as a male-specific autoantigen. Notably, TGM4 is a prostatic secretory molecule with critical role in male reproduction. TGM4 autoantibodies were detected in most of the adult male APS1 patients but were absent in all the young males. Consecutive serum samples further revealed that TGM4 autoantibodies first presented during...

Thymic epithelial cells (TECs) support T cell development in the thymus. Cortical thymic epithelial cells (cTECs) facilitate positive selection of developing thymocytes whereas medullary thymic epithelial cells (mTECs) facilitate the deletion of self-reactive thymocytes in order to prevent autoimmunity. The mTEC compartment is highly dynamic with continuous maturation and turnover, but the genetic regulation of these processes remains poorly understood. MicroRNAs (miRNAs) are important regulators of TEC genetic programs since miRNA-deficient TECs are severely defective. However, the individual miRNAs important for TEC maintenance and function and their mechanisms of action remain unknown. Here, we demonstrate that miR-205 is highly and preferentially expressed in mTECs during both thymic ontogeny and in the postnatal thymus. This distinct expression is suggestive of functional importance for TEC biology. Genetic ablation of miR-205 in TECs, however, neither revealed a role for miR-2...

Cell detachment from the extracellular matrix triggers anoikis. Disseminated tumor cells must adapt to survive matrix deprivation, while still retaining the ability to attach at secondary sites and re-initiate cell division. In this study, we illuminate mechanisms that enable reversible matrix attachment by breast cancer cells. Matrix deprival triggered AMPK activity and concomitantly inhibited AKT activity by upregulating the AKT phosphatase PHLPP2. The resultant pAMPKhigh/pAKTlow state was critical for cell survival in suspension, as PHLPP2 silencing also increased anoikis while impairing autophagy and metastasis. In contrast, matrix re-attachment led to AKT-mediated AMPK inactivation via PP2C-α-mediated restoration of the pAKThigh/pAMPKlow state. Clinical specimens of primary and metastatic breast cancer displayed an AKT-associated gene expression signature, whereas circulating breast tumor cells displayed an elevated AMPK-dependent gene expression signature. Our work establishes...

Mud crabs usually inhabit brackish water bodies of South-East Asia including India. The biological significance of the species is its survibility in wide range of hydro-biological fluctuating environments including salinity. The life cycle of the species includes two important larval stages at which they are vulnerable to various predators. Pathophysiological status of the species is a challenge for its aquaculture. Inspite of a huge economical and high food values, informations on biochemical, molecular, physiological, ecological and taxonomical aspects of mud crabs (Scylla sp.) in comparison to other important aquaculture candidates are very limited. The present review is an attempt to string together various informations available on mud crabs (S. serrata) so that it will provide a platform to have all the basic informations regarding the species for interested workers. It is believed that understanding the pathology, ecophysiology, genetics and reproduction of the species in its natural environment will not only help in its conservation but also will help in its enhanced production.

The enzyme catalase breaks down H2O2, a potentially harmful oxidant, to H2O and O2. Besides oxidase activity, the enzyme also exhibits peroxidase activity. Therefore, it plays an important role in maintaining health and regulating pathophysiology of the organisms. However, 3D structure of this important enzyme in invertebrates particularly in crabs is not yet available. Therefore, an attempt has been made to predict the structure of the crab catalase and to envisage its catalytic interaction with H2O2. A three dimensional model of crab catalase was constructed using the NADPH binding site on Beef Liver catalase from Bos taurus (PDBID: 7CAT) as template by comparative modeling approach. Backbone conformation of the modeled structure by PROCHECK revealed that more than 98% of the residues fell in the allowed regions, ERRAT results confirmed good quality of modeled structure and VERIFY3D profile was satisfying. Molecular docking has been used to know the binding modes of hydrogen peroxide with the crab catalase protein. The receptor structures used for docking were derived from molecular dynamics (MD) simulations of homology modeled structure. The docking results showed that the three important determinant residues Arg68, Val70 and Arg108 in catalase were binding with H2O2 as they had strong hydrogen bonding contacts with the substrate. Our analysis provides insight into the structural properties of crab catalase and defines its active sites for binding with substrate. These data are important for further studies of catalase of invertebrates in general and that of crabs in particular.

In the present study, the role of vitamin E and curcumin on hyperthyroidism induced mitochondrial oxygen consumption and oxidative damage to lipids and proteins of rat liver are reported. Adult male rats were rendered hyperthyroid by administration of 0.0012% l-thyroxine in their drinking water, while vitamin E (200 mg/kg body weight) and curcumin (30 mg/kg body weight) were supplemented orally for 30 days. Hyperthyroidism induced elevation in serum aspartate aminotransferase and alanine aminotransferase activities were reduced significantly in response to vitamin E and curcumin treatment. On the other hand, effects of vitamin E and curcumin on hyperthyroidism induced hepatic complexes I and II mediated respiration were found to be different. While curcumin administration ameliorates hyperthyroidism induced state 3 and state 4 respiration in complex I, vitamin E treatment was effective only in reducing state 4 respiration of complex I. On the contrary, curcumin administration was ineffective in modulating hyperthyroidism induced complex II respiration, but vitamin E treatment to hyperthyroid rats resulted in augmentation of complex II respiration both at state 3 and state 4 level. Moreover, vitamin E and curcumin treatment resulted in alleviation of hyperthyroidism induced lipid peroxidation. Enhanced protein carbonylation in hyperthyroid rats is decreased only in response to simultaneous supplementation of vitamin E and curcumin. Above findings suggest that both vitamin E and curcumin have differential regulation on complexes I and II mediated mitochondrial respiration and have a protective role against l-thyroxine induced hepatic dysfunction and oxidative stress.

The effects of salinity (10, 17 and 35 ppt) on O 2 consumption, CO 2 release and NH 3 excretion by crabs and oxidative stress parameters and antioxidant defenses of its tissues were reported. An increase in salinity caused a decrease in O 2 consumption and CO 2 release and an increase in ammonia excretion by crabs. Lipid peroxidation, protein carbonyl, H 2 O 2 levels and total antioxidant capacity of the tissues elevated significantly at 35 ppt salinity except in abdominal muscle where H 2 O 2 content was low. Ascorbic acid content of tissues was higher at 17 ppt salinity than at 10 and 35 ppt salinities. With increasing salinity, a gradual decrease in SOD, an increase in catalase, no change in GPx and a decrease followed by an increase in GR activities were recorded for abdominal muscle. While for hepatopancreas, an increase followed by a decrease in SOD and catalase, decrease in GPx and GR activities were noticed with increasing salinity. In the case of gills, a decrease followed by an increase in SOD, a decrease in catalase and GPx and an increase in GR activities were noted when the salinity increased from 10 ppt to 35 ppt. These results suggest that salinity modulation of oxidative stress and antioxidant defenses in Scylla serrata is tissue specific.

Aims: In the present study, the effects of vitamin E and curcumin on hepatic dysfunction, mitochondrial oxygen consumption as well as hyperlipidemia in hypothyroid rats are reported. Main methods: Adult male rats were rendered hypothyroid by administration of 0.05% 6-n-propyl-2thiouracil (PTU) in their drinking water, while vitamin E (200 mg/kg body weight) and curcumin (30 mg/kg body weight) were supplemented orally for 30 days. Key findings: Hypothyroidism-induced elevation in serum aspartate aminotransferase activity was found to decline in vitamin E and curcumin treated rats. Nevertheless, distorted histoarchitecture revealed in hypothyroid rat liver was alleviated to normal by vitamin E and curcumin treatment. Regulation of hypothyroidism induced decrease in complexes I and II mediated mitochondrial respiration by vitamin E and curcumin was found to be different. Administration of curcumin to hypothyroid rats alleviates the decreased state 4 respiration and increased respiratory control ratio (RCR) level in complex I mediated mitochondrial oxygen consumption, whereas complex II mediated respiration was not influenced by exogenous antioxidants. Although, increase in serum concentration of total cholesterol was not modified by exogenous antioxidants, increased level of non-high-density lipoprotein cholesterol (non-HDL-C) in serum of hypothyroid rats was further enhanced by vitamin E and curcumin. Moreover, a significant elevation in mitochondrial lipid peroxidation and protein carbonylation was noticed in hypothyroid groups treated with vitamin E and curcumin. Significance: The present study suggests that supplementation of curcumin and vitamin E enhances oxidative stress parameters and hyperlipidemia; nevertheless, it protects hypothyroid-induced altered rectal temperature, serum transaminase activity and hepatic histoarchitecture.

Mitochondrial respiration, activities of electron transport chain enzymes and formation of oxidative stress parameters were investigated in mitochondria isolated from gill tissue of mud crabs (Scylla serrata) as a function of salinity (10 ppt, 17 ppt and 35 ppt). Mitochondrial oxygen consumption rate was higher for succinate as substrate compared with those of glutamate, malate and pyruvate. Complex I and complex II mediated respirations were higher at low salinity (10 ppt) than high salinity (17 ppt and 35 ppt). Although activities of electron transport chain enzymes particularly complexes I (EC 1.6.5.3), II (EC 1.3.99.1) and II-III (EC 1.3.2.1) were elevated linearly in response to salinity treatment, activity of complex V (ATPase, EC 3.6.1.34) was decreased at 35 ppt salinity. However, ATPase activity was higher at 17 ppt salinity in comparison to 10 ppt and 17 ppt salinity. Results of the experiment suggest that high salinity (35 ppt) causes hypoxic state in mitochondria of mud crabs. Hypoxic condition induced by high salinity was accompanied with increased hydrogen peroxide production resulting oxidative stress in mitochondria of crabs. A possible mechanism of hypoxia-induced reactive oxygen species generation and OS due to salinity stress in the crabs is discussed.

Humans have a strong natural instinct to know every cause, consequences and mechanism of natural processes. By gathering the knowledge and information about these natural processes, they have developed a big pile of molecular libraries which can mimic or imitate these delicate, highly environmental/biological/chemical specific reactions. One of these reactions is dismutation reaction that includes conversion of superoxide radical anion (O 2˙− ) to peroxide catalysed by the enzyme called as superoxide dismutase (SOD) and the reaction is also called as SOD biocatalytic process. In the reaction, the chemical entity O 2˙− gets oxidized and reduced at the same time and hence the name dismutation is offered for the reaction .