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91.
Mustapha Benmoussa Sandip Mukhopadhyay Yves Desjardins 《Plant Cell, Tissue and Organ Culture》1997,47(1):91-94
The effects of different growth regulators on induction and growth of callus ofAsparagus densiflorus cv. Sprengeri were studied. Calluses grew more rapidly on Murashige and Skoog basal medium supplemented with 5.4 μM p-chlorophenoxyacetic
acid (pCPA) and 4.4 μM 6-benzylaminopurine (BA) (medium 1) as compared to the same medium with 11.3 μM 2,4-dichlorophenoxyacetic
acid (2,4-d) and 4.6 μM kinetin (medium 2). Calluses on medium 1 were soft and friable, whereas, compact, hard calluses originated on
medium 2. Different concentrations and combinations of BA and/or kinetin were also used to study their effects on shoot regeneration.
Kinetin was found to be less effective than BA in the initiation of shoots (1.8 shoots/callus). High numbers of shoots were
produced in the presence of 0.4 μM BA alone (3.3 shoots/callus). The addition of ancymidol (5 μM) in MS with 0.4 μM BA enhanced
multiplication of shoots (9.8 shoots/explant) and also produced well-developed crowns. 相似文献
92.
Fiona McDonnell Mustapha Irnaten Abbot F. Clark Colm J. O’Brien Deborah M. Wallace 《PloS one》2016,11(4)
PurposeFibrosis and a hypoxic environment are associated with the trabecular meshwork (TM) region in the blinding disease glaucoma. Hypoxia has been shown to alter DNA methylation, an epigenetic mechanism involved in regulating gene expression such as the pro-fibrotic transforming growth factor (TGF) β1 and the anti-fibrotic Ras protein activator like 1 (RASAL1). The purpose of this study was to compare DNA methylation levels, and the expression of TGFβ1 and RASAL1 in primary human normal (NTM) with glaucomatous (GTM) cells and in NTM cells under hypoxic conditions.MethodsGlobal DNA methylation was assessed by ELISA in cultured age-matched NTM and GTM cells. qPCR was conducted for TGFβ1, collagen 1α1 (COL1A1), and RASAL1 expression. Western immunoblotting was used to determine protein expression. For hypoxia experiments, NTM cells were cultured in a 1%O2, 5%CO2 and 37°C environment. NTM and GTM cells were treated with TGFβ1 (10ng/ml) and the methylation inhibitor 5-azacytidine (5-aza) (0.5μM) respectively to determine their effects on DNA Methyltransferase 1 (DNMT1) and RASAL1 expression.ResultsWe found increased DNA methylation, increased TGFβ1 expression and decreased RASAL1 expression in GTM cells compared to NTM cells. Similar results were obtained in NTM cells under hypoxic conditions. TGFβ1 treatment increased DNMT1 and COL1A1, and decreased RASAL1 expression in NTM cells. 5-aza treatment decreased DNMT1, TGFβ1 and COL1A1 expression, and increased RASAL1 expression in GTM cells.ConclusionsTGFβ1 and RASAL1 expression, global DNA methylation, and expression of associated methylation enzymes were altered between NTM and GTM cells. We found that hypoxia in NTM cells induced similar results to the GTM cells. Furthermore, DNA methylation, TGFβ1 and RASAL1 appear to have an interacting relationship that may play a role in driving pro-fibrotic disease progression in the glaucomatous TM. 相似文献
93.
Aim of the present study was to investigate the effects of two key environmental factors of estuarine ecosystems, salinity and hypoxia, on the physiological attributes in reed plants (Phragmites australis (Cav.) Trin. ex Steudel). Growth, leaf gas exchange, water (and ion) relations, and osmotic adjustment were determined in hydroponically grown plants exposed to hypoxia at varying NaCl-salinity concentrations (0, 50, 100, and 200 mM). Plants grew well under hypoxia treatment with standard nutrient solution without added salt and at NaCl concentrations up to 100 mM. Reed plants were able to produce and allocate phytomass to all their organs even at the highest salt level (200 mM NaCl). In plants subjected to hypoxia at various water potentials no clear relationships were found between growth and photosynthetic parameters except for gs, whereas growth displayed a highly significant correlation with plant–water relations. A and gs of reed plants treated with hypoxia at varying water potential of nutrient solutions were positively correlated and the former variable also had a strong positive relationship with E. Leaf Ψw and Ψπ followed a similar trend and declined significantly as water potential of watering solutions was lowered. Highly significant positive correlations were identified between leaf Ψw and photosynthetic parameters. At all NaCl concentrations, the increase in total inorganic ions resulted from increased Na+ and Cl− while K+, Ca2+, and Mg2+ concentrations decreased with increasing osmolality of nutrient solutions. Common reed has an efficient mechanism of Na+ exclusion from the leaves and exhibited a high leaf K+/Na+ selectivity ratio over a wide range of salinities under hypoxia treatment. In Phragmites australis grown in 200 mM NaCl, K+ contributed 17% toΨπ, whereas Na+ and Cl− accounted for only 11% and 6%, respectively. At the same NaCl concentration, the estimated contribution of proline to Ψπ was less than 0.2%. Changes in leaf turgor occurred with a combined effect of salinity and hypoxia, suggesting that reed plants could adjust their water status sufficiently. 相似文献
94.
Mustapha Aouida Kangchang Kim Abdul Rajjak Shaikh Jose M. Pardo J?rg Eppinger Dae-Jin Yun Ray A. Bressan Meena L. Narasimhan 《PloS one》2013,8(6)
Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc) activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc) in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p). The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides’ ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA) signaling and AMP activated protein kinase (AMPK) phosphorylation in S. cerevisiae, which are homologous to important mammalian adiponectin-AdipoR1 signaling pathways. This system should facilitate the development of therapeutic inventions targeting adiponectin and/or AdipoR physiology. 相似文献
95.
Elena G. Govorunova Mustapha Moussaif Andrey Kullyev Ken C. Q. Nguyen Thomas V. McDonald David H. Hall Ji Y. Sze 《PloS one》2010,5(4)
The C. elegans eat-6 gene encodes a Na+, K+-ATPase α subunit and is a homolog of the familial hemiplegic migraine candidate gene FHM2. Migraine is the most common neurological disorder linked to serotonergic dysfunction. We sought to study the pathophysiological mechanisms of migraine and their relation to serotonin (5-HT) signaling using C. elegans as a genetic model. In C. elegans, exogenous 5-HT inhibits paralysis induced by the acetylcholinesterase inhibitor aldicarb. We found that the eat-6(ad467) mutation or RNAi of eat-6 increases aldicarb sensitivity and causes complete resistance to 5-HT treatment, indicating that EAT-6 is a component of the pathway that couples 5-HT signaling and ACh neurotransmission. While a postsynaptic role of EAT-6 at the bodywall NMJs has been well established, we found that EAT-6 may in addition regulate presynaptic ACh neurotransmission. We show that eat-6 is expressed in ventral cord ACh motor neurons, and that cell-specific RNAi of eat-6 in the ACh neurons leads to hypersensitivity to aldicarb. Electron microscopy showed an increased number of synaptic vesicles in the ACh neurons in the eat-6(ad467) mutant. Genetic analyses suggest that EAT-6 interacts with EGL-30 Gαq, EGL-8 phospholipase C and SLO-1 BK channel signaling to modulate ACh neurotransmission and that either reduced or excessive EAT-6 function may lead to increased ACh neurotransmission. Study of the interaction between eat-6 and 5-HT receptors revealed both stimulatory and inhibitory 5-HT inputs to the NMJs. We show that the inhibitory and stimulatory 5-HT signals arise from distinct 5-HT neurons. The role of eat-6 in modulation of excitatory neurotransmission by 5-HT may provide a genetic explanation for the therapeutic effects of the drugs targeting 5-HT receptors in the treatment of migraine patients. 相似文献
96.
Haouassi Mustapha Kergosien Yannick Mendoza Jorge E. Rousseau Louis-Martin 《Flexible Services and Manufacturing Journal》2022,34(3):614-645
Flexible Services and Manufacturing Journal - Fast delivery is one of the most popular services in e-commerce retail. It consists in shipping the items ordered on-line in short times. Customer... 相似文献
97.
98.
High‐level primary clarithromycin resistance of Helicobacter pylori in Morocco: a prospective multicenter molecular study
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99.
Haddach M Pierre F Regan CF Borsan C Michaux J Stefan E Kerdoncuff P Schwaebe MK Chua PC Siddiqui-Jain A Macalino D Drygin D O'Brien SE Rice WG Ryckman DM 《Bioorganic & medicinal chemistry letters》2012,22(1):45-48
Protein kinase CK2 is a potential drug target for many diseases including cancer and inflammation disorders. The crystal structure of clinical candidate CX-4945 1 with CK2 revealed an indirect interaction with the protein through hydrogen bonding between the NH of the 3-chlorophenyl amine and a water molecule. Herein, we investigate the relevance of this hydrogen bond by preparing several novel tricyclic derivatives lacking a NH moiety at the same position. This SAR study allowed the discovery of highly potent CK2 inhibitors. 相似文献
100.
Victor Certal Frank Halley Angela Virone-Oddos Fabienne Thompson Bruno Filoche-Rommé Youssef El-Ahmad Jean-Christophe Carry Cécile Delorme Andreas Karlsson Pierre-Yves Abecassis Loic Vincent Hélène Bonnevaux Jean-Paul Nicolas Renaud Morales Nadine Michot Isabelle Vade Audrey Louboutin Sébastien Perron Gilles Doerflinger Bernadette Tric Laurent Schio 《Bioorganic & medicinal chemistry letters》2012,22(20):6381-6384
From a HTS campaign, a new series of pyrimidone anilides exemplified by compound 1 has been identified with good inhibitory activity for the PI3Kβ isoform. The structure of compound 1 in PI3Kγ was solved revealing a binding mode in agreement with the SAR observed on PI3Kβ. These compounds displayed inhibition in the nanomolar range in the biochemical assay and were also potent p-Akt inhibitors in a PTEN-deficient PC3 prostate cancer cell line. Optimization of in vitro pharmocokinetic properties led to compound 25 exhibiting 52% bioavailability in mice and target engagement in an acute PK/PD study. 相似文献