Development of novel peptide inhibitor of Lipoxygenase based on biochemical and BIAcore evidences

Lipoxygenase (LOX) are enzymes implicated in a broad range of inflammatory diseases, cancer, asthma and atherosclerosis. These diverse biological properties lead to the interesting target for the inhibition of this metabolic pathway of LOX. The drugs available in the market against LOX reported to have various side effects. To develop potent and selective therapeutic agents against LOX, it is essential to have the knowledge of its active site. Due to the lack of structural data of human LOX, researchers are using soybean LOX (sLOX) because of their availability and similarities in the active site structure. Based on the crystal structure of sLOX-3 and its complex with known inhibitors, we have designed a tripeptide, FWY which strongly inhibits sLOX-3 activity. The inhibition by peptide has been tested with purified sLOX-3 and with LOX present in blood serum of breast cancer patients in the presence of substrate linoleic acid and arachidonic acid respectively. The dissociation constant (K(D)) of the peptide with sLOX-3 as determined by Surface Plasmon Resonance (SPR) was 3.59x10(-9) M. The kinetic constant (K(i)) and IC(50), as determined biochemical methods were 7.41x10(-8) M and 0.15x10(-6) M respectively.     

An immunohistochemical method for identifying fibroblasts in formalin-fixed, paraffin-embedded tissue.

Fibroblasts are critical for tissue homeostasis, and their inappropriate proliferation and activation can result in common and debilitating conditions including fibrosis and cancer. We currently have a poor understanding of the mechanisms that control the growth and activation of fibroblasts in vivo, in part because of a lack of suitable fibroblast markers. We have taken advantage of an antibody previously shown to stain stromal cells in frozen tissues (TE-7) and identified conditions in which it can be used to stain fibroblasts and myofibroblasts in the paraffin-embedded tissue samples routinely collected for pathological analysis. We show that this antibody recognizes growing and quiescent fibroblasts and myofibroblasts by immunohistochemistry, immunofluorescence, and ELISA assays. We also present its staining patterns in normal tissue samples and in breast tumors.     

Goblet cell-derived resistin-like molecule beta augments CD4+ T cell production of IFN-gamma and infection-induced intestinal inflammation

The secreted goblet cell-derived protein resistin-like molecule beta (RELMbeta) has been implicated in divergent functions, including a direct effector function against parasitic helminths and a pathogenic function in promoting inflammation in models of colitis and ileitis. However, whether RELMbeta influences CD4(+) T cell responses in the intestine is unknown. Using a natural model of intestinal inflammation induced by chronic infection with gastrointestinal helminth Trichuris muris, we identify dual functions for RELMbeta in augmenting CD4(+) Th1 cell responses and promoting infection-induced intestinal inflammation. Following exposure to low-dose Trichuris, wild-type C57BL/6 mice exhibit persistent infection associated with robust IFN-gamma production and intestinal inflammation. In contrast, infected RELMbeta(-/-) mice exhibited a significantly reduced expression of parasite-specific CD4(+) T cell-derived IFN-gamma and TNF-alpha and failed to develop Trichuris-induced intestinal inflammation. In in vitro T cell differentiation assays, recombinant RELMbeta activated macrophages to express MHC class II and secrete IL-12/23p40 and enhanced their ability to mediate Ag-specific IFN-gamma expression in CD4(+) T cells. Taken together, these data suggest that goblet cell-macrophage cross-talk, mediated in part by RELMbeta, can promote adaptive CD4(+) T cell responses and chronic inflammation following intestinal helminth infection.     

In Vitro Propagation and Conservation of Dendrobium lituiflorum Lindl Through Protocorm-Like Bodies

Axillary buds obtained from 5-month-old in vitro growing plants of Dendrobium lituiflorum Lindl were cultured in Murashige and Skoog (MS) medium supplemented with different concentrations of 2,4-D. Fastest initiation (13.3 days) of protocormlike bodies (PLBs) was observed in cultures containing MS medium supplemented with 0.5 mg l^?1 2,4-D. Maximum explant response of 83% was also observed in the same medium. PLBs obtained in MS medium containing 0.5 mg l^?1 2,4-D showed maximum regeneration potential of seedlings (19 explant^?1) when subcultured in MS medium. Well developed shoots and roots of the seedlings were obtained in the medium containing 0.5 mg l^?1 each of NAA and BAP, in combination. Encapsulated PLBs of D. lituiflorum could be stored at 8°C for 90 days with 80% regeneration. However, it was observed that regeneration potential of encapsulated PLBs reduced with further storage. Seventy seven per cent hardened plants survived and bloomed after 2.5 years of hardening.     

On the isolation and evaluation of a novel unsubstituted 5-nitroimidazole derivative as an agent to target tumor hypoxia

The presence and extent of hypoxic regions in cancerous tissue bears a negative influence on the effectiveness of radiation therapy and chemotherapy of the cancer hence estimation of hypoxia is an important problem. Several (99m)Tc-labeled nitroimidazole-based non-invasive agents have been tried for this purpose but none had optimal characteristics and the search continues. Herein we report, for the first time to the best of our knowledge, the isolation, (99m)Tc(CO)(3) labeling and evaluation of an unsubstituted 5-nitroimidazole derivative obtained as a side product during the synthesis of 4-nitroimidazole derivative. The (99m)Tc(CO)(3)-labeled complex of 5-nitroimidazole derivative could be prepared in excellent yield under mild conditions. Its evaluation in fibrosarcoma tumor bearing Swiss mice showed uptake and slow clearance of injected activity from tumor. The tumor-to-muscle ratio was found to be very high but tumor-to-blood ratio greater than 1 could not be obtained throughout the limited time point study. The study revealed that complex under investigation has features similar to other 2-nitroimidazole complexes so far as the retention of injected activity in tumor is concerned.     

Increased sulfate uptake by E. coli overexpressing the SLC26-related SulP protein Rv1739c from Mycobacterium tuberculosis.

Growth and virulence of mycobacteria requires sulfur uptake. The Mycobacterium tuberculosis genome contains, in addition to the ABC sulfate permease cysTWA, three SLC26-related SulP genes of unknown function. We report that induction of Rv1739c expression in E. coli increased bacterial uptake of sulfate, but not Cl(-), formate, or oxalate. Uptake was time-dependent, maximal at pH 6.0, and exhibited a K(1/2) for sulfate of 4.0 muM. Na(+)-independent sulfate uptake was not reduced by bicarbonate, nitrate, or phosphate, but was inhibited by sulfite, selenate, thiosulfate, N-ethylmaleimide and carbonyl cyanide 3-chloro-phenylhydrazone. Sulfate uptake was also increased by overexpression of the Rv1739c transmembrane domain, but not of the cytoplasmic C-terminal STAS domain. Mutation to serine of the three cysteine residues of Rv1739c did not affect magnitude, pH-dependence, or pharmacology of sulfate uptake. Expression of Rv1739c in a M. bovis BCG strain lacking the ABC sulfate permease subunit CysA could not complement sulfate auxotrophy. Moreover, inducible expression of Rv1739c in an E. coli strain lacking CysA did not increase sulfate uptake by intact cells. Our data show that facilitation of bacterial sulfate uptake by Rv1739c requires CysA and its associated sulfate permease activity, and suggest that Rv1739c may be a CysTWA-dependent sulfate transporter.