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91.
Nakazawa T Takahashi H Nishijima K Shimura M Fuse N Tamai M Hafezi-Moghadam A Nishida K 《Journal of neurochemistry》2007,100(4):1018-1031
Excitotoxicity is a major cause of retinal ganglion cell (RGC) death during ischemic diseases such as vessel occlusion and diabetic retinopathy. However, the underlying mechanisms are not well understood. Statins, inhibitors of the HMG-CoA reductase, have neuroprotective effects in addition to their original role in lowering cholesterol. We hypothesize that pitavastatin, a recently introduced potent statin, is protective against N-methyl-d-aspartic acid (NMDA)-induced RGC death. Pitavastatin, administered by gavage, abolished NMDA-induced loss of RGCs. To elucidate the mechanisms underlying the neuroprotective effect of pitavastatin, we investigated its impact on inflammation. NMDA increased the expression of interleukin-1beta and TNF-alpha, and endothelial adhesion molecules, including ICAM-1, and induced leukocyte accumulation in the retinal vessels. Pitavastatin significantly reduced NMDA-induced leukocyte accumulation and up-regulation of endothelial adhesion molecules, whereas cytokine expression was unaffected. Systemic blockade of ICAM-1 in wild-type mice or absence of CD18 in gene-deficient (CD18(-/-)) mice significantly suppressed NMDA-induced leukocyte accumulation and RGC death. These findings suggest a novel and causative role for inflammatory leukocyte recruitment in NMDA-induced excitotoxicity. Furthermore, we show the novel neuroprotective effect of statins against excitotoxicity-induced RGC death. Statins or other anti-inflammatory agents may thus have therapeutic benefits in excitotoxicity-associated neuronal diseases through blockade of leukocyte recruitment. 相似文献
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94.
Ali Bagheri Seher Karaman Erkul Ali Asghar Maassoumi Mohammad Reza Rahiminejad Frank R. Blattner 《Nordic Journal of Botany》2015,33(5):532-539
As the result of surveying the relevant type specimens, together with macro‐ and micro‐morphological studies, chromosome counting and ITS sequencing, Astragalus trifoliastrum was found to be a species independent of A. laguriformis (with which it has peviously been synonymized). In contrast, A. wanensis, assumed to be a synonym of A. trifoliastrum, indeed appears to be identical with A. trifoliastrum. The diploid chromosome number of 2n = 16 is reported for the first time for A. trifoliastrum. 相似文献
95.
Mee Lee Looi Saiful Anuar Karsani Mariati Abdul Rahman Ahmad Zailani Hatta Mohd Dali Siti Aishah Md Ali Wan Zurinah Wan Ngah Yasmin Anum Mohd Yusof 《Journal of biosciences》2009,34(6):917-925
Although cervical cancer is preventable with early detection, it remains the second most common malignancy among women. An understanding of how proteins change in their expression during a particular diseased state such as cervical cancer will contribute to an understanding of how the disease develops and progresses. Potentially, it may also lead to the ability to predict the occurrence of the disease. With this in mind, we aimed to identify differentially expressed proteins in the plasma of cervical cancer patients. Plasma from control, cervical intraepithelial neoplasia (CIN) grade 3 and squamous cell carcinoma (SCC) stage IV subjects was resolved by two-dimensional gel electrophoresis and the resulting proteome profiles compared. Differentially expressed protein spots were then identified by mass spectrometry. Eighteen proteins were found to be differentially expressed in the plasma of CIN 3 and SCC stage IV samples when compared with that of controls. Competitive ELISA further validated the expression of cytokeratin 19 and tetranectin. Functional analyses of these differentially expressed proteins will provide further insight into their potential role(s) in cervical cancer-specific monitoring and therapeutics. 相似文献
96.
Bassam R. Ali Ian Nouvel Alistair N. Hume 《Biochemical and biophysical research communications》2010,397(1):34-41
Ras super-family small GTPases regulate diverse cellular processes such as vesicular transport and signal transduction. Critical to these activities is the ability of these proteins to target to specific intracellular membranes. To allow association with membranes Ras-related GTPases are post-translationally modified by covalent attachment of prenyl groups to conserved cysteine residues at or near their C-terminus. Here we used the HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase (HMGCR) inhibitor mevastatin to develop a ‘prenylation block-and-release’ assay that allows membrane targeting of prenylated proteins to be visualized in living cells. Using this assay we investigated the cytosol to membrane targeting of several small GTPases to compartments of the secretory and endocytic pathways. We found that all Rabs tested were targeted directly to the membrane on which they reside at steady-state and not via an intermediate location as reported for Ras and Rho proteins. However, we observed that the kinetics of cytosol to membrane targeting differed for each Rab tested. Comparison of the mevastatin sensitivity and kinetics of membrane targeting of Rab23, Rab23 prenylation motif mutants and H-Ras revealed that these parameters are strongly dependent upon the prenyl transferase with Rab geranylgeranyl transferase substrates exhibiting higher sensitivity and requiring greater time to recover from mevastatin inhibition than farnesyl transferase substrates. We propose that this assay is a useful tool to investigate the kinetics, biological functions and the mechanisms of membrane targeting of prenylated proteins. 相似文献
97.
Basharat Ali Anjum Nasim Sabri Karin Ljung Shahida Hasnain 《World journal of microbiology & biotechnology》2009,25(3):519-526
Sixteen Bacillus strains isolated from rhizosphere, histoplane and phyllosphere of different plant species were identified by 16S rDNA gene
sequencing and evaluated for in vitro auxin production as well as growth stimulation of Vigna radiata (L.) Wilczek. Auxin production by Bacillus spp. in L-broth medium supplemented with 1,000 μg ml−1
L-tryptophan ranges from 0.60 to 3.0 μg IAA ml−1 as revealed by gas chromatography and mass spectrometric (GC–MS) analysis. Rhizospheric isolates exhibit relatively more
IAA synthesis than histoplane and phyllosphere isolates. Plant microbe interaction experiments conducted under gnotobiotic
conditions recorded 55.55, 46.46 and 46.20% increase in shoot length with Bacillus megaterium MiR-4, B. pumilus NpR-1 and B. subtilis TpP-1, respectively, over control. Bacillus inoculations also increased shoot fresh weight with B. megaterium MiR-4 (60.94%) and B. pumilus NpR-1 (37.76%). Highly significant positive correlation between auxin production analyzed by GC–MS and shoot length (r = 0.687**, P = 0.01) and shoot fresh weight (r = 0.703**, P = 0.01) was noted under gnotobiotic conditions. Similarly, significant correlation was also found between auxin production
by Bacillus spp. (GC–MS analysis) and different growth parameters such as shoot length (r = 0.495*, P = 0.05), number of pods (r = 0.498*, P = 0.05) and grain weight (r = 0.537*, P = 0.05) at full maturity under natural wire house conditions. Results showed that auxin production potential of plant associated
Bacillus spp. can be effectively exploited to enhance the growth and yield of V. radiata. 相似文献
98.
The 29-kilodalton thiol-dependent peroxidase of Entamoeba histolytica is a factor involved in pathogenesis and survival of the parasite during oxidative stress 下载免费PDF全文
The 29-kDa surface antigen (thiol-dependent peroxidase; Eh29) of Entamoeba histolytica exhibits peroxidative and protective antioxidant activities. During tissue invasion, the trophozoites are exposed to oxidative stress and need to deal with highly toxic reactive oxygen species (ROS). In this investigation, attempts have been made to understand the role of the 29-kDa peroxidase gene in parasite survival and pathogenesis. Inhibition of eh29 gene expression by antisense RNA technology has shown approximately 55% inhibition in eh29 expression, maximum ROS accumulation, and significantly lower viability in 29-kDa downregulated trophozoites during oxidative stress. The cytopathic and cytotoxic activities were also found to decrease effectively in the 29-kDa downregulated trophozoites. Size of liver abscesses was substantially lower in hamsters inoculated with 29-kDa downregulated trophozoites compared to the normal HM1:IMSS. These findings clearly suggest that the 29-kDa protein of E. histolytica has a role in both survival of trophozoites in the presence of ROS and pathogenesis of amoebiasis. 相似文献
99.
Rac is a dominant regulator of cadherin-directed actin assembly that is activated by adhesive ligation independently of Tiam1 总被引:1,自引:0,他引:1
Kraemer A Goodwin M Verma S Yap AS Ali RG 《American journal of physiology. Cell physiology》2007,292(3):C1061-C1069
Classic cadherins function as adhesion-activated cell signaling receptors. On adhesive ligation, cadherins induce signaling cascades leading to actin cytoskeletal reorganization that is imperative for cadherin function. In particular, cadherin ligation activates actin assembly by the actin-related protein (Arp)2/3 complex, a process that critically affects the ability of cells to form and extend cadherin-based contacts. However, the signaling pathway(s) that activate Arp2/3 downstream of cadherin adhesion remain poorly understood. In this report we focused on the Rho family GTPases Rac and Cdc42, which can signal to Arp2/3. We found that homophilic engagement of E-cadherin simultaneously activates both Rac1 and Cdc42. However, by comparing the impact of dominant-negative Rac1 and Cdc42 mutants, we show that Rac1 is the dominant regulator of cadherin-directed actin assembly and homophilic contact formation. To pursue upstream elements of the Rac1 signaling pathway, we focused on the potential contribution of Tiam1 to cadherin-activated Rac signaling. We found that Tiam1 or the closely-related Tiam2/STEF1 was recruited to cell-cell contacts in an E-cadherin-dependent fashion. Moreover, a dominant-negative Tiam1 mutant perturbed cell spreading on cadherin-coated substrata. However, disruption of Tiam1 activity with dominant-negative mutants or RNA interference did not affect the ability of E-cadherin ligation to activate Rac1. We conclude that Rac1 critically influences cadherin-directed actin assembly as part of a signaling pathway independent of Tiam1. actin cytoskeleton; Cdc42; E-cadherin 相似文献
100.
Antagonistic effects of simultaneous exposure of ergot alkaloids on kidney adenosine triphosphatase system 总被引:1,自引:0,他引:1
Moubarak AS Johnson ZB Rosenkrans CF 《In vitro cellular & developmental biology. Animal》2003,39(8-9):395-398
Much of the research on fescue toxicosis has concentrated on evaluating animal response to grazing endophyte-infected (E+) versus endophyte-free tall fescue or the effects of single toxins such as ergonovine (EN), ergovaline (EV), or ergotamine (ET) on animal performance. Such approaches have eliminated the opportunity to test the possible additive, synergistic, or antagonistic interactions of one or more ergot alkaloids with the other ergot alkaloids found in E+ tall fescue. This study was conducted to determine the effects of simultaneous exposure of pairs of EN, EV, and ET on the kidney adenosine triphosphatase (ATPase) system in vitro. Tests were performed using three separate rat kidney homogenates and were repeated four times at concentrations of 0, 75, and 200 microM. Individually, EN, EV, and ET induced dose-dependent inhibitions of kidney Na(+)/K(+) ATPase, with EN being most potent, followed by purified EV, and then by ET. The ergot alkaloids inhibited Mg(2+) ATPase to a lesser degree than Na(+)/K(+) ATPase, with EN again being the most potent toxin. Simultaneous exposure to any combination of the ergot alkaloid pairs tested (EV + ET, EV + EN, and ET + EN) resulted in significant interactions (P < 0.05), indicating antagonistic effects on the inhibition of Na(+)/K(+) ATPase and Mg(2+) ATPase for most concentration combinations. These interactions suggest that in studies of the effects of any ergot alkaloid on animal performance, effects of other ergot alkaloids may also be present. Effects may not be additive, as was the case in this study, and the presence of one toxin may enhance or hinder the effectiveness of others. 相似文献