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951.
Receptor activator of NF-kappaB ligand induction via Jak2 and Stat5a in mammary epithelial cells 总被引:5,自引:0,他引:5
Srivastava S Matsuda M Hou Z Bailey JP Kitazawa R Herbst MP Horseman ND 《The Journal of biological chemistry》2003,278(46):46171-46178
Prolactin (PRL) is the primary hormone that, in conjunction with local factors, leads to lobuloalveolar development during pregnancy. Recently, receptor activator of NF-kappaB ligand (RANKL) has been identified as one of the effector molecules essential for lobuloalveolar development. The molecular mechanisms by which PRL may induce RANKL expression have not been carefully examined. Here we report that RANKL expression in the mammary gland is developmentally regulated and dependent on PRL and progesterone, whereas its receptor RANK (receptor activator of NF-kappaB) and decoy receptor osteoprotegerin (OPG) are constitutively expressed at all stages in both normal (PRL+/-) and prolactin knockout (PRL-/-) mice. In vitro, PRL markedly increased RANKL expression in primary mammary epithelial cells and RANKL-luciferase reporter activity in CHOD6 cells, which constitutively express the PRL receptor. We identified a gamma-interferon activation sequence (GAS) in the region between residues -965 to -725 of the RANKL promoter, which conferred a PRL response. Using dominant negative mutants of recombinant Jak2 and Stat5 in CHOD6 cells, and by reconstituting the Jak2/Stat5 pathway in COS7 cells, we determined that Jak2 and Stat5a are essential for the PRL-induced RANKL expression in mammary gland. 相似文献
952.
The rhizomes of the rare plant Podophyllum hexandrum contain podophyllotoxin, which is a precursor of the anticancer drugs etoposide and teniposide. Batch cultivation of Podophyllum hexandrum was conducted using optimized medium in a 3 L bioreactor, which resulted in biomass and podophyllotoxin concentrations of 21.4 g/L and 13.8 mg/L in 24 and 26 days, respectively. The batch kinetics was used to identify the mathematical model. The model was extrapolated to identify the nutrient feeding rate (150 mL/d) and substrate concentration (105 g/L) in the incoming feed for nonlimiting and noninhibitory glucose concentration in the cell retention bioreactor. An improvement in cell growth to 53 g/L and intracellular podophyllotoxin accumulation of 48.8 mg/L was achieved in 60 days, when the bioreactor was operated in continuous cell retention cultivation mode. 相似文献
953.
Tewari N Tiwari VK Mishra RC Tripathi RP Srivastava AK Ahmad R Srivastava R Srivastava BS 《Bioorganic & medicinal chemistry》2003,11(13):2911-2922
Glycosyl amino esters (2-13) on reaction with different isocyanates resulted in quantitative conversion to glycosyl ureas (14--32). Few of the selected ureas (15-20, 22-28, 30 and 32) on cyclative amidation with DBU/TBAB/4 A MS gave respective dihydropyrimidinones in fair to good yields (33-47). The compounds were screened for alpha-glucosidase inhibitory activity and two (19 and 23) of them showed strong inhibition against rat intestinal alpha-glucosidase. The compounds were also screened against Mycobacterium aurum, however, only one (19) of them exhibited marginal antitubercular activity. 相似文献
954.
Kumar A Bansal D Bajaj K Sharma S Archana Srivastava VK 《Bioorganic & medicinal chemistry》2003,11(23):5281-5291
Diazotization of N-benzylidene anthranilic acids 1a-1n at pH 9 yielded N-[alpha-(phenylazo) benzylidene] anthranilic acids 2a-2n and at pH 3 yielded N-benzylidene-5-(phenylazo) anthranilic acids 3a-3n. When compounds 3a-3n were treated with thioglycolic/thiolactic acid in the presence of anhydrous ZnCl(2), 2-(4-oxo-2-phenylthiazolidin-3-yl)-5-(phenylazo) benzoic acids 4a-4n were afforded. The newly synthesized compounds were screened for their anti-inflammatory and analgesic activities and were compared with standard drugs, aspirin and phenylbutazone. Out of the compounds studied, the most active compound 4n showed more potent activity than the standard drugs at all doses tested. 相似文献
955.
Shannon JM McCormick-Shannon K Burhans MS Shangguan X Srivastava K Hyatt BA 《American journal of physiology. Lung cellular and molecular physiology》2003,285(6):L1323-L1336
Proteoglycans (PGs) have been shown to play a key role in the development of many tissues. We have investigated the role of sulfated PGs in early rat lung development by treating cultured tissues with 30 mM sodium chlorate, a global inhibitor of PG sulfation. Chlorate treatment disrupted growth and branching of embryonic day 13 lung explants. Isolated lung epithelium (LgE) migrated toward and invaded lung mesenchyme (LgM), and chlorate irreversibly suppressed this response. Chlorate also inhibited migration of LgE toward beads soaked in FGF10. Chlorate severely decreased branching morphogenesis in tissue recombinants consisting of LgM plus either LgE or tracheal epithelium (TrE) and decreased expression of surfactant protein C gene (SP-C). Chlorate also reduced bone morphogenetic protein-4 expression in cultured tips and recombinants but had no effect on the expression of clara cell 10-kDa protein (CC10), sonic hedgehog (Shh), FGF10, and FGF receptor 2IIIb. Chlorate reduced the growth of LgE in mesenchyme-free culture but did not affect SP-C expression. In contrast, chlorate inhibited both rudiment growth and the induction of SP-C in mesenchyme-free cultured TrE. Treatment of lung tips and tissue recombinants with chondroitinase ABC abolished branching morphogenesis. Chondroitinase also suppressed growth of TrE in mesenchyme-free culture. Chondroitinase treatment, however, had no effect on the induction of SP-C expression in any of these cultures. These results demonstrate the overall importance of sulfated PGs to normal lung development and demonstrate a dynamic role for chondroitin sulfate PGs in embryonic lung growth and morphogenesis. 相似文献
956.
Srivastava S 《Journal of experimental zoology. Part A, Comparative experimental biology》2003,295(1):17-28
The pineal window is a transparent/translucent pineal covering on the dorsal surface of the cranium of certain fishes and is associated with light reactions of fish. In the present study, catfish species Clarias batrachus, Heteropneustes fossilis, Mystus vittatus, M. seenghala, and M. cavassius were examined for the type of pineal window present. Two morphologically different types of pineal window were found: an opaque-looking pineal window in C. batrachus and H. fossilis and a translucent type of pineal window in M. vittatus, M. seenghala, and M. cavassius. The distributional pattern of pigments in the melanophores at the pineal window were studied in terms of Melanophore Index (MI). In all of the species studied, a pineal foramen, a subepidermal lens-like tissue, and pineal end vesicle were present. Experiments were carried out on catfish having the opaque pineal window, as it is uncommon in catfish. Catfish with normal and shielded pineal window were exposed to conditions of artificial constant illumination (LL) and darkness (DD) to evaluate the effects of altered photoperiods on the state of pigmentation of melanophores at the pineal window. Recordings of diel activity patterns, which are light dependent in catfish, were carried out under both natural and artificial photoperiods in fish with a normal or shielded window in order to assess its functional nature. The existence of two morphologically and functionally different types of pineal window in a relatively closely related group of catfish has been demonstrated in this study. The nature of the opaque type of pineal window has been reconsidered based on new experimental evidence. 相似文献
957.
Rudresh Jain R Dani V Mitra A Srivastava S Sarma SP Varadarajan R Ramakumar S 《Protein engineering》2002,15(8):627-633
While it is well known that introduction of Pro residues into the interior of protein alpha-helices is destabilizing, there have been few studies that have examined the structural and thermodynamic effects of the replacement of a Pro residue in the interior of a protein alpha-helix. We have previously reported an increase in stability in the P40S mutant of Escherichia coli thioredoxin of 1-1.5 kcal/mol in the temperature range 280-330 K. This paper describes the structure of the P40S mutant at a resolution of 1.8 A. In wild-type thioredoxin, P40 is located in the interior of helix two, a long alpha-helix that extends from residues 32 to 49 with a kink at residue 40. Structural differences between the wild-type and P40S are largely localized to the above helix. In the P40S mutant, there is an expected additional hydrogen bond formed between the amide of S40 and the carbonyl of residue K36 and also additional hydrogen bonds between the side chain of S40 and the carbonyl of K36. The helix remains kinked. In the wild-type, main chain hydrogen bonds exist between the amide of 44 and carbonyl of 40 and between the amide of 43 and carbonyl of 39. However, these are absent in P40S. Instead, these main chain atoms are hydrogen bonded to water molecules. The increased stability of P40S is likely to be due to the net increase in the number of hydrogen bonds in helix two of E.coli thioredoxin. 相似文献
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