Revue du Marche Commun no. 78 = Review of the Common Market March 1965 No. 78

Argonaute family proteins are well conserved among all organisms. Its role in mitotic cell cycle progression and apoptotic cell elimination is poorly understood. Earlier we have established the contribution of Ago-1 in cell cycle control related to G2/M cyclin in Drosophila. Here we have extended our study in understanding the relationship of Ago-1 in regulating apoptosis during Drosophila development. Apoptosis play a critical role in controlling organ shape and size during development of multi cellular organism. Multifarious regulatory pathways control apoptosis during development among which highly conserved JNK (c-Jun N-terminal kinase) pathway play a crucial role. Here we have over expressed Ago-1 in Drosophila eye and brain by employing UAS (upstream activation sequence)-GAL4 system under the expression of eye and brain specific driver. Over expression of Ago-1 resulted in reduced number of ommatidia in the eye and produced smaller size brain in adult and larval Drosophila. A drastic reversal of the phenotype towards normal was observed upon introduction of a single copy of the dominant negative mutation of basket (bsk, Drosophila homolog of JNK) indicating an active and physical involvement of the bsk with Ago-1 in inducing developmental apoptotic process. Further study showed that Ago-1 stimulates phosphorylation of JNK through transforming growth factor-β activated kinase 1- hemipterous (Tak1-hep) axis of JNK pathway. JNK phosphorylation results in up regulation of pro-apoptotic genes head involution defective (hid), grim & reaper (rpr) and induces activation of Drosophila caspases (cysteinyl aspartate proteinases);DRONC (Death regulator Nedd2-like caspase), ICE (alternatively Drice, Death related ICE-like caspase) and DCP1 (Death caspase-1) by inhibiting apoptotic inhibitor protein DIAP1 (Death-associated inhibitor of apoptosis 1). Further, Ago-1 also inhibits miR-14 expression to trigger apoptosis. Our findings propose that Ago-1 acts as a key regulator in controlling cell death, tumor regression and stress response in metazoan providing a constructive bridge between RNAi machinery and cell death

Chalcone-imidazolone conjugates induce apoptosis through DNA damage pathway by affecting telomeres

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one of the most prevalent cancers in the world and more than one million women are diagnosed leading to 410,000 deaths every year. In our previous studies new chalcone-imidazolone conjugates were prepared and evaluated for their anticancer activity in a panel of 53 human tumor cell lines and the lead compounds identified were 6 and 8. This prompted us to investigate the mechanism of apoptotic event.</p> <p>Results</p> <p>Involvement of pro-apoptotic protein (Bax), active caspase-9 and cleavage of retinoblastoma protein was studied. Interestingly, the compounds caused upregulation of p21, check point proteins (Chk1, Chk2) and as well as their phosphorylated forms which are known to regulate the DNA damage pathway. Increased p53BP1 foci by immunolocalisation studies and TRF1 suggested the possible involvement of telomere and associated proteins in the apoptotic event. The telomeric protein such as TRF2 which is an important target for anticancer therapy against human breast cancer was extensively studied along with proteins involved in proper functioning of telomeres.</p> <p>Conclusions</p> <p>The apoptotic proteins such as Bax, active caspase-9 and cleaved RB are up-regulated in the compound treated cells revealing the apoptotic nature of the compounds. Down regulation of TRF2 and upregulation of the TRF1 as well as telomerase assay indicated the decrease in telomeric length revealing telomeric dysfunction and thereby controlling the rapid rate of cell proliferation. In summary, chalcone-imidazolone conjugates displayed significant DNA damage activity particularly at telomeres and caused both apoptosis and senescence-like growth arrest which suggested that these compounds have potential activity against breast carcinoma.</p

Effect of Benzothiazole based conjugates in causing apoptosis by Regulating p53, PTEN and MAP Kinase proteins affecting miR-195a and miR-101-1

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) accounts for majority of liver cancers and is the leading cause of cancer related death in Asia. Like any other cancer, HCC develops when there is a mutation to the cellular machinery that causes the cell to replicate at a higher rate and results in the loss of apoptosis. Therefore, a delicate balance between the expression of various genes involved in proliferation and apoptosis decide the ultimate fate of the cell to undergo rapid proliferation (cancer) or cell death.</p> <p>Results</p> <p>The benzothiazole based compounds exhibited effective cytotoxicity at 4 μM concentration and have shown G1 cell cycle arrest with decrease in levels of G1 cell cycle proteins such as cyclin D1 and Skp2. Involvement of tumour suppressor proteins such as PTEN and p53 was studied. Interestingly these compounds displayed decrease in the phosphorylated forms of AKT, p38 MAPK and ERK1/2 which play a vital role in cell proliferation. Compounds have exhibited strong and significant effect on the expression of micro RNAs such as miR-195a & miR-101-1 which regulate hepatic cell proliferation.</p> <p>Conclusions</p> <p>The cell cycle arrest and apoptotic inducing nature of these compounds was revealed by FACS, BrdU cell proliferation and tunel assays. Compounds affected both tumour suppressor proteins as well as proteins that are involved in active cell proliferation. Micro RNAs whose target is Cyclin D1 such as miR-195a and miR-101-1 that is required for growth of hepatoma cells was drastically affected. These compounds caused apoptosis by activating caspase-3 and PARP.</p

Genetic divergence for yield attributing traits in the Rabi sorghum germplasm

Mahalanobis D2 statistics was used to assess the divergence among the 45 rabi sorghum landraces, 13 advanced breeding lines and 4 popular cultivars. The analysis of variance revealed significant differences among the genotypes for all the 7 traits studied. The 62 genotypes were grouped into 15 clusters where cluster I was the largest comprising of 41 genotypes followed by cluster III with 7 genotypes and cluster XI with 2 genotypes. The inter cluster distance was maximum between cluster XIII and XIV followed by cluster XIV and XV, cluster XII and XV, cluster XII and XIII and cluster V and XIV. Based on the inter cluster distance and per se performance, the elite variety Phule Anuradha, the landraces RSV 1426, SSRG 147, Pusegaon local and the advanced breeding line RSV 1420 can be utilized in breeding programmes as potential parents for crop improvement. Seed yield contributed maximum to divergence (31.84 %) followed by plant height (20.62 %) and days to 50% flowering (14.38 %)

Not Available

Not AvailableA study was conducted to evaluate the genetic variability parameters, correlation and path coefficient analysis for eight yield related traits in segregating F2 population of an aerobic restorer AR 9-18 × YPK 198 (Donor for yield enhancing genes Gn1a and OsSPL14) at ICAR-IIRR, Hyderabad during the kharif, 2019. The results indicated that, productive tiller number, grain number per panicle and plant yield showed high PCV and GCV. Height of plant, productive tiller number, grain number per panicle and plant yield exhibited a high heritability and also high genetic advance as per cent of mean which indicates simple selection would be effective for enhancement of these traits. Correlation studies indicated that plant yield was associated significantly positive with height of plant, productive tiller number, length of panicle and grain number per panicle. High positive direct effect on plant yield was recorded by productive tiller number, grain number per panicle and height of plant.Not Availabl

<i>Ago-1</i> over expression induces apoptosis in <i>Drosophila</i> eye.

<p><b>I.</b> (<b>A)</b> Western blot analysis showing the expression of proteins isolated from adult fly heads of wild type and <i>Ago-1</i> over expressed stocks. (<b>B)</b> Graphical presentation of AGO1 band intensity relative to β-Actin loading control. The average from three independent experiments was taken and plotted. <b>II.</b> (<b>A1-A2, B1-B2, C1-C2)</b> Acridine Orange (AO) staining showing more apoptotic population (marked by arrow head)in <i>Ago-1</i> over expressed 3^rd instar larval eye imaginal disc compared to wild type and down regulated group. (<b>D1 and D2</b>) AO positive cells reduced significantly in <i>Ago-1</i> over expressed eye disc upon introduction of baculovirus p35 trans-gene in fly eye. (<b>E1 and E2</b>) Over expression of transgenic control protein (GFP) in developing eye can’t increase AO positive cells in developing fly eye. (<b>A’, B’, C’)</b> Scanning electron micrograph of adult eyes showing reduced number of normal ommatidia in <i>Ago-1</i> over expressed line. (<b>D’</b>) baculovirus p35 protein can inhibit <i>Ago-1</i> over expression induced apoptotic phenotype in fly eye (<b>E’</b>) GFP over expression can’t induce <i>Ago-1</i> over expression like eye phenotype (<b>III.)</b> <i>Drosophila</i> JNK pathway is triggered by <i>Ago-1</i> over expression. <b>(A)</b> Adult eye phenotype of <i>Ago-1</i> over expressed fly under Scanning Electron Microscope (SEM). <b>(A’)</b> Ommatidia structure of same fly. <b>(III. B.)</b> Adult eye phenotype of <i>tak1</i> deficient mutant, <b>(B’)</b> same in higher magnification. <b>(C)</b> Adult eye phenotype of dominant negative mutation of <i>basket</i>, <b>(C’)</b> magnified view of same showing complete recovery of ommatidia morphology. <b>(D)</b> Adult eye phenotype of <i>bsk</i> deficient with <i>Ago-1</i> over expression showing partial recovery <b>(D’)</b> ommatidia morphology. <b>(E)</b> Mutation in <i>hid</i> gene (<i>hid</i>^<i>H109</i>) prevents <i>Ago-1</i> over expression induced apoptotic phenotype in adult fly eye as well as <b>(E’)</b> Ommatidia structure of the same.</p

<i>Ago-1</i> over expression results in elevated levels of JNK phosphorylation.

<p><b>I.</b> Western blot analysis showing the increased level of JNK phosphorylation in <i>Ago-1</i> over expressed (<i>UAS Ago-1/GMR GAL4</i>) and reduced level in mutant background (<i>Ago-1</i>^<i>72</i><i>/Ago-1</i>^<i>45</i> and <i>GMR GAL4</i>; <i>TRiP</i>.<i>HM04006</i>). Histogram presents mean relative band density (±SEM). <b>II. (A)</b> <i>Ago-1</i> over expression in 3^rd instar larval eye/antennal disc by imaginal discs specific GAL4 [<i>P{w[+mW</i>.<i>hs] = GawB}32B</i>]. <b>(A’)</b> <i>Ago-1</i> over expression in the antennal part of the same disc, <b>(A”)</b> Retinal part, <b>(A”‘)</b> Preproneural part. <b>(B-B”‘)</b> JNK phosphorylated areas of the disc. <b>(C-C”‘)</b> <i>Ago-1</i> over expression co localizes with JNK phosphorylated area of the disc. <b>(D-D”‘)</b> DAPI stained part of the same disc. <b>(E-E”‘)</b> Merged figure. <b>III.</b> <i>Ago-1</i> over expression in 3^rd instar larval eye disc by eye discs specific GAL4 (<i>GMR GAL4</i>). <b>(A-A”)</b> <i>Ago-1</i> over expression in the eye disc, <b>(B-B”)</b> JNK phosphorylated areas of the disc. <b>(C-C”)</b> <i>Ago-1</i> over expression co localizes with JNK phosphorylated area of the disc. <b>(D-D”‘)</b> DAPI staining indicates nuclear region of eye disc cells <b>(E-E”)</b> Merged image.</p