Augmentation of RBP4/STRA6 signaling leads to insulin resistance and inflammation and the plausible therapeutic role of vildagliptin and metformin

A role of Retinol Binding Protein-4 (RBP4) in insulin resistance is widely studied. However, there is paucity of information on its receptor viz., Stimulated by Retinoic Acid-6 (STRA6) with insulin resistance. To address this, we investigated the regulation of RBP4/STRA6 expression in 3T3-L1 adipocytes exposed to glucolipotoxicity (GLT) and in visceral adipose tissue (VAT) from high fat diet (HFD) fed insulin-resistant rats. 3T3-L1 adipocytes were subjected to GLT and other experimental maneuvers with and without vildagliptin or metformin. Real-time PCR and western-blot experiments were performed to analyze RBP4, STRA6, PPARγ gene and protein expression. Adipored staining and glucose uptake assay were performed to evaluate lipid and glucose metabolism. Oral glucose tolerance test (OGTT) and Insulin Tolerance Test (ITT) were performed to determine the extent of insulin resistance in HFD fed male Wistar rats. Total serum RBP4 was measured by quantitative sandwich enzyme-linked immunosorbent assay kit. Adipocytes under GLT exhibited significantly increased RBP4/STRA6 expressions and decreased insulin sensitivity/glucose uptake. Vildagliptin and metformin not only restored the above but also decreased the expression of IL-6, NFκB, SOCS-3 along with lipid accumulation. Furthermore, HFD fed rats exhibited significantly increased serum levels of RBP4 along with VAT expression of RBP4, STRA6, PPARγ, IL-6. These molecules were significantly altered by the vildagliptin/ metformin treatment. We conclude that RBP4/STRA6 pathway is primarily involved in mediating inflammation and insulin resistance in adipocytes and visceral adipose tissues under glucolipotoxicity and in insulin resistant rats.

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Dual-substrate inhibition kinetic studies for recombinant human interferon gamma producing Pichia pastoris

Pichia pastoris is considered as one of the prominent host extensively used as a platform for heterologous protein production. In the present study, the growth inhibition kinetics of recombinant P. pastoris expressing human interferon gamma was studied under different initial substrate concentrations of gluconate (10–100?g?L^?1) and methanol (2–50?g?L^?1) in modified FM22 medium. The highest specific growth rate of 0.0206 and 0.019?hr^?1 was observed at 60?g?L^?1 of gluconate and 10?g?L^?1 of methanol, respectively. Various three- and four-parametric Monod-variant models were chosen to analyze the inhibition kinetics. The model parameters as well as goodness of fit were estimated using nonlinear regression analysis. The three-parameter Haldane model was found to be best fit for both gluconate (R²?=?0.95) and methanol substrate (R²?=?0.96). The parameter sensitivity analysis revealed that µ_max, K_i, and K_s are the most sensitive parameters for both methanol and gluconate. Different substrate inhibition models were fitted to the growth kinetic data and the additive form of double Webb model was found to be the best to explain the growth kinetics of recombinant P. pastoris.     

Changes in blood proteins in the cockroach Periplaneta americana after chemosterilization with metepa

Polyacrylamide gel disc electrophoretic studies on the blood proteins of the adult female cockroach Periplaneta americana made sterile by chemical and by surgical means revealed certain differences. While in surgically sterilized animals only the less mobile protein fractions corresponding to soluble oocyte proteins increased in concentration in the blood, in chemosterilized females certain of the more mobile fractions in addition to those corresponding to the less mobile soluble oocyte proteins showed an increase. Various fractions which registered an initial increase in the chemosterilized females showed a tendency to decrease with time, whereas after surgical sterilization they continued to remain higher. However, ovarian degeneration appeared to be irreversible after chemosterilization. Chemosterilization in the female is accompanied by derangement of protein metabolism and inability of the follicle epithelium to take up even available oocyte proteins from the haemolymph.

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Zusammenfassung Mit Hilfe der Polyakrylamid-Gelscheibe unternommene elektrophoretische Untersuchungen der Blutproteinkörper erwachsener weiblicher Küchenschaben (Periplaneta americana), die durch chemische und chirurgische Mittel sterilisiert worden waren, ergaben gewisse Abweichungen. Während bei chirurgisch sterilisierten Tieren nur die weniger beweglichen Proteinkörperanteile, die den Oozytenproteinen entsprechen, in ihrer Konzentration im Blut anstiegen, zeigten bei chemosterilisierten Weibchen sowohl die beweglicheren als auch die weniger beweglichen Anteile eine Zunahme. Verschiedene Anteile, die bei den chemosterilisierten Weibchen anfänglich mit einem Anstieg reagierten, neigten im Laufe der Zeit dazu, wieder abzunehmen, während sie nach chirurgischer Sterilisation stets höher blieben. Jedoch schien nach Chemosterilisation die Eierstockentartung unwiderruflich zu sein. Als Begleiterscheinungen der Chemosterilisation ergeben sich also Störungen im Proteinmetabolismus und die Unfähigkeit des Follikelepithels, selbst die in der Haemolymphe vorhandenen Oozytenproteinkörper aufzunehmen.

     

Effect of environmental factors on seed germination and seedling emergence of Viola prionantha,a cleistogamous plant

Journal of Plant Research - Environmental conditions during seed development and maturation can affect seed traits and germination behavior, yet systematic research on the effects of seed...     

Differential sensitivity of callus derived from immature panicles of rice cultivars to the non-specific toxin of Pyricularia grisea

An in vitro screening procedure was adapted to study the sensitivity of callus to the toxin picolinic acid of Pyricularia grisea in four rice cultivars. The lethal dose LD₅₀ was determined on the basis of probit-log dosage response curve. The values of LD₅₀ were 10, 51, 129 and 151 ppm for Tetep, Newbonnet, Labelle and M 201, respectively. The callus culture of cultivar Tetep, with a known broad spectrum of resistance, exhibited a high toxin sensitivity whereas the highly susceptible cultivar M 201 showed low sensitivity indicating the absence of relation between host plant specific resistance to blast and resistance of the callus to toxin. This revised version was published online in June 2006 with corrections to the Cover Date.     

Anti-neoplastic pharmacophore benzophenone-1 coumarin (BP-1C) targets JAK2 to induce apoptosis in lung cancer

Reigning of the abnormal gene activation associated with survival signalling in lung cancer leads to the anomalous growth and therapeutic failure. Targeting specific cell survival signalling like JAK2/STAT3 nexus has become a major focus of investigation to establish a target specific treatment. The 2-bromobenzoyl-4-methylphenoxy-acetyl hydra acetyl Coumarin (BP-1C), is new anti-neoplastic agent with apoptosis inducing capacity. The current study was aimed to develop antitumor phramacophore, BP-1C as JAK2 specific inhibitor against lung neoplastic progression. The study validates and identifies the molecular targets of BP-1C induced cell death. Cell based screening against multiple cancer cell lines identified, lung adenocarcinoma as its specific target through promotion of apoptosis. The BP-1C is able to induce, specific hall marks of apoptosis and there by conferring anti-neoplastic activity. Validation of its molecular mechanism, identified, BP-1C specifically targets JAK2^Tyr1007/1008 phosphorylation, and inhibits its downstream STAT3^Tyr705 signalling pathway to induce cell death. As a consequence, modulation in Akt/Src survival signal and altered expression of interwoven apoptotic genes were evident. The results were reproducible in an in-vivo LLC tumor model and in-ovo xenograft studies. The computational approaches viz, drug finger printing confers, BP-1C as novel class JAK2 inhibitor and molecular simulations studies assures its efficiency in binding with JAK2. Overall, BP-1C is a novel JAK2 inhibitor with experimental evidence and could be effectively developed into a promising drug for lung cancer treatment.

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Purification and molecular and biological characterisation of the 1-hydroxyphenazine,produced by an environmental strain of Pseudomonas aeruginosa

Pseudomonas aeruginosa—an opportunistic pathogen, perhaps best known for chronic lung infections, produces wide range of pigments that possess specific activities which either assist the organism’s survival or bring about changes within host. A similar blue-green diffusible pigment producing P. aeruginosa was isolated from dug-well water, so as to extract 1-hydroxyphenazine from its crude pigment. The compound was purified from the crude pigment using column chromatography followed by a preparative thin layer chromatography that showed a single yellow spot. Further molecular characterisation of the purified component was carried out using UV–Vis spectrophotometer, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectroscopy which showed respective peaks corresponding to 1-hydroxyphenazine. Biological characterisation using in vitro assays revealed that 1-hydroxyphenazine showed anti-bacterial activity only against Bacillus sp. and a concentration of 30 µg/ml induced noticeable morphological alteration in A549 human lung adenocarcinoma cells followed by cell death after 48 h. Thus, such active components within bacterial pigments can be characterized and used as possible anti-bacterial or anti-cancer agents.     

Genomic Insights into the Evolutionary Origin of Xanthomonas axonopodis pv. citri and Its Ecological Relatives

Xanthomonas axonopodis pv. citri (Xac) is the causal agent of citrus bacterial canker (CBC) and is a serious problem worldwide. Like CBC, several important diseases in other fruits, such as mango, pomegranate, and grape, are also caused by Xanthomonas pathovars that display remarkable specificity toward their hosts. While citrus and mango diseases were documented more than 100 years ago, the pomegranate and grape diseases have been known only since the 1950s and 1970s, respectively. Interestingly, diseases caused by all these pathovars were noted first in India. Our genome-based phylogenetic studies suggest that these diverse pathogens belong to a single species and these pathovars may be just a group of rapidly evolving strains. Furthermore, the recently reported pathovars, such as those infecting grape and pomegranate, form independent clonal lineages, while the citrus and mango pathovars that have been known for a long time form one clonal lineage. Such an understanding of their phylogenomic relationship has further allowed us to understand major and unique variations in the lineages that give rise to these pathovars. Whole-genome sequencing studies including ecological relatives from their putative country of origin has allowed us to understand the evolutionary history of Xac and other pathovars that infect fruits.