02849nas a2200253   4500008004100000245015900041210006900200260000800269300001200277490000700289520195000296100002102246700001302267700001902280700002102299700001802320700001902338700001502357700002302372700002602395700002502421700001802446856013102464       2017                        eng d00aCamptothecin-producing endophytic bacteria from pyrenacantha volubilis hook. (Icacinaceae): a possible role of a plasmid in the production of camptothecin0 aCamptothecinproducing endophytic bacteria from pyrenacantha volu  cDEC  a160-1670 v363 aBackground: Camptothecin (CPT), a quinoline alkaloid, is a potent inhibitor of eukaryotic topoisomerase I. Because of this property, several derivatives of CPT are used as chemotherapeutic agents. CPT is produced by several plant species belonging to the Asterid clade as well as by a number of endophytic fungal associates of these plants. In this study, we report the production of CPT by four bacterial endophytes and show the possible role of a plasmid in the biosynthesis of CPT. 

Methods: Endophytic bacteria were isolated from leaves, stems and fruits of Pyrenacantha volubilis Hook. (Icacinanceae). The bacterial isolates were purified and analyzed for production of CPT by ESI-MS/MS and NMR analysis. Bacterial identity was established based on the morphology and 16s rRNA sequence analysis. Crude extracts of the bacterial endophytes were evaluated for their cytotoxicity using colon cancer cell lines. The role of plasmid in the production of CPT was studied by purging the plasmid, using acriflavine, as well as reconstituting the bacteria with the plasmid. 

Results: Four bacterial isolates, Bacillus sp. (KP125955 and KP125956), Bacillus subtilis (KY741853) and Bacillus amyloliquefaciens (KY741854) were found to produce CPT in culture. Both based on ESI-MS/MS and NMR analysis, the identity of CPT was found to be similar to that produced by the host plant. The CPT was biologically active as evident by its cytotoxicity against colon cancer cell line. The production of CPT by the endophyte (Bacillus subtilis, KY741853) attenuated with sub-culture. A likely role of a plasmid in the production of CPT was established. A 5 kbp plasmid was recovered from the bacteria. Bacterial isolate cured of plasmid failed to produce CPT. 

Conclusion: Our study implies a possible role of a plasmid in the production of CPT by the endophytic bacteria and opens up further work to unravel the exact mechanisms that might be involved.1 aSoujanya, K., N.1 aSiva, R.1 aKumara, Mohana1 aSrimany, Amitava1 aRavikanth, G.1 aMulani, F., A.1 aAarthy, T.1 aThulasiram, H., V.1 aSanthoshkumar, T., R.1 aNataraja, Karaba, N.1 aShaanker, Uma  uhttps://library.ncl.res.in/content/camptothecin-producing-endophytic-bacteria-pyrenacantha-volubilis-hook-icacinaceae-possible02820nas a2200241   4500008004100000245011400041210006900155260000800224300001400232490000700246520197800253100002402231700002002255700001502275700002102290700002002311700002402331700002402355700002202379700002302401700002502424856012902449       2017                        eng d00aMethylglyoxal attenuates insulin signaling and downregulates the enzymes involved in cholesterol biosynthesis0 aMethylglyoxal attenuates insulin signaling and downregulates the  cNOV  a2338-23490 v133 a<p>Methylglyoxal (MG) is a highly reactive dicarbonyl known to be elevated under the hyperglycemic conditions of diabetes and is implicated in the development of diabetic complications. Therefore, the current study investigates the role of MG in exacerbating insulin resistance at the insulin signaling level, as well as its effect on the global proteomic level. By using insulin sensitive rat muscle cells (L6) and Chinese hamster ovary (CHO) cells stably expressing the insulin receptor (IR) and a glucose transporter fused with green fluorescent protein (GLUT4-GFP), we have observed that MG impairs insulin signaling, inhibits GLUT4 translocation and reduces glucose uptake. SWATH MS analysis, a label-free quantitative mass spectrometric approach, showed altered expression of 99 proteins out of 2404 identified in response to MG treatment. These proteins are mainly involved in stress response, protein folding and proteolysis. Some of the deregulated proteins such as thioredoxin 2, glutathione S transferase, T complex protein 1 subunit beta (tcbp1), heat shock protein 90 and E3 ubiquitin ligase were previously reported to be associated with either diabetes or insulin resistance. Interestingly, aminoguanidine (AMG), a potent dicarbonyl scavenger, restored the deleterious effects of MG. For the first time, we report that MG induces downregulation of enzymes involved in cholesterol biosynthesis such as acetyl-CoA acetyltransferase, hydroxymethylglutaryl-CoA synthase, farnesyl pyrophosphate synthetase, squalene monooxygenase, and lanosterol synthase. GC MS analysis for sterol metabolites corroborated the proteomic results; MG significantly reduced cholesterol production whereas AMG treatment restored cholesterol production to levels similar to the control. Thus, MG leads to primary defects in insulin signaling and cellular abnormalities at the proteomic and metabolic levels, both of which may contribute to the development of insulin resistance.</p>
1 aDeshmukh, Arati, B.1 aBai, Shakuntala1 aAarthy, T.1 aKazi, Rubina, S.1 aBanarjee, Reema1 aRathore, Rajeshwari1 aVijayakumar, M., V.1 aThulasiram, H. V.1 aBhat, Manoj, Kumar1 aKulkarni, Mahesh, J.  uhttps://library.ncl.res.in/content/methylglyoxal-attenuates-insulin-signaling-and-downregulates-enzymes-involved-cholesterol