HIV-1 glycoprotein 120 (gp120) is known to cause neurotoxicity via several mechanisms including production of proinflammatory cytokines/chemokines and oxidative stress. Likewise, drug abuse is thought to have a direct impact on the pathology of HIV-associated neuroinflammation through the induction of proinflammatory cytokines/chemokines and oxidative stress. In the present study, we demonstrate that gp120 and methamphetamine (MA) causes apoptotic cell death by inducing oxidative stress through the cytochrome P450 (CYP) and NADPH oxidase (NOX) pathways. The results showed that both MA and gp120 induced reactive oxygen species (ROS) production in concentration- and time-dependent manners. The combination of gp120 and MA also induced CYP2E1 expression at both mRNA (1.7±0.2- and 2.8±0.3-fold in SVGA and primary astrocytes, respectively) and protein (1.3±0.1-fold in SVGA and 1.4±0.03-fold in primary astrocytes) levels, suggesting the involvement of CYP2E1 in ROS production. This was further confirmed by using a selective inhibitor of CYP2E1, diallylsulfide (DAS), and CYP2E1 knockdown using siRNA, which significantly reduced ROS production (30–60%). As the CYP pathway is known to be coupled with the NOX pathway, including Fenton–Weiss–Haber (FWH) reaction, we examined whether the NOX pathway is also involved in ROS production induced by either gp120 or MA. Our results showed that selective inhibitors of NOX, diphenyleneiodonium (DPI), and FWH reaction, deferoxamine (DFO), also significantly reduced ROS production. These findings were further confirmed using specific siRNAs against NOX2 and NOX4 (NADPH oxidase family). We then showed that gp120 and MA both induced apoptosis (caspase-3 activity and DNA lesion using TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling) assay) and cell death. Furthermore, we showed that DAS, DPI, and DFO completely abolished apoptosis and cell death, suggesting the involvement of CYP and NOX pathways in ROS-mediated apoptotic cell death. In conclusion, this is the first report on the involvement of CYP and NOX pathways in gp120/MA-induced oxidative stress and apoptotic cell death in astrocytes, which has clinical implications in neurodegenerative diseases, including neuroAIDS.
methamphetamine; gp120; cytochrome P450; astrocytes; oxidative stress
This study deals with anilofos tolerance and its mineralization by the common rice field cyanobacterium Synechocystis sp. strain PUPCCC 64. The organism tolerated anilofos up to 25 mg L−1. The herbicide caused inhibitory effects on photosynthetic pigments of the test organism in a dose-dependent manner. The organism exhibited 60, 89, 96, 85 and 79% decrease in chlorophyll a, carotenoids, phycocyanin, allophycocyanin and phycoerythrin, respectively, in 20 mg L−1 anilofos on day six. Activities of superoxide dismutase, catalase and peroxidase increased by 1.04 to 1.80 times over control cultures in presence of 20 mg L−1 anilofos. Glutathione content decreased by 26% while proline content was unaffected by 20 mg L−1 anilofos. The test organism showed intracellular uptake and metabolized the herbicide. Uptake of herbicide by test organism was fast during initial six hours followed by slow uptake until 120 hours. The organism exhibited maximum anilofos removal at 100 mg protein L−1, pH 8.0 and 30°C. Its growth in phosphate deficient basal medium in the presence of anilofos (2.5 mg L−1) indicated that herbicide was used by the strain PUPCCC 64 as a source of phosphate.
Higher expression of reactive oxygen species (ROS) is implicated in neurological disorders. A major event in glaucoma, the death of retinal ganglion cells (RGCs), has been associated with elevated levels of glutamate and TNF-α in the RGCs’ local microenvironment. Herein we show that the transduction of Peroxiredoxin 6 (PRDX6) attenuates TNFα- and glutamate-induced RGC death, by limiting ROS and maintaining Ca2+ homeostasis. Immunohistochemical staining of rat retina disclosed the presence of PRDX6 in RGCs, and Western and real-time PCR analysis revealed an abundance of PRDX6 protein and mRNA. RGCs treated with glutamate and/or TNF-α displayed elevated levels of ROS and reduced expression of PRDX6, and underwent apoptosis. A supply of PRDX6 protected RGCs from glutamate and TNF-α induced cytotoxicity by reducing ROS level and NF-kB activation, and limiting increased intracellular Ca2+ influx. Results provide a rationale for use of PRDX6 for blocking ROS-mediated pathophysiology in glaucoma and other neuronal disorders.
Lens epithelium-derived growth factor (LEDGF) maintains survival pathways by augmenting the transcription of stress-response genes such as small heat-shock protein 27. Recently, aberrant expression of LEDGF was found in prostate cancer (PC). Herein, we showed that LEDGF overexpression upregulated Hsp27 in PC cells, DU145, PC-3 and LNCaP and promoted antiapoptotic pathways in PCs. We found that these cells had higher abundance of Hsp27, which was correlated with the levels of LEDGF expression. Transactivation assay in DU145 cells revealed that transactivation of Hsp27 was related to the magnitude of LEDGF expression. Silencing of LEDGF in DU145 cells abrogated Hsp27 expression and inhibited stimulated cell proliferation, invasiveness and migration. These cells were arrested in S and G2 phase, and failed to accumulate cyclin B1, and showed increased apoptosis. Furthermore, LEDGF-depleted DU145 cells displayed elevated Bax and cleaved caspase 9 expression and reduced levels of Bcl2, Bcl-XL. The activated survival pathway(s), ERK1/2 and Akt, were selectively decreased in these cells, which characteristically have lower tumorigenicity. Conversely, the depleted cells, when re-overexpressed with LEDGF or Hsp27, regained tumorigenic properties. Collectively, results reveal the involvement of LEDGF-mediated elevated expression of Hsp27-dependent survival pathway(s) in PC. Our findings suggest new lines of investigation aimed at developing therapies by targeting LEDGF or its aberrant expression-associated stimulated antiapoptotic pathway(s).
LEDGF; transcription; Hsp27; DU145; PWR-1E; apoptosis
Peroxiredoxin 6 (Prdx6) is a pleiotropic oxidative stress-response protein that defends cells against reactive oxygen species (ROS)-induced damage. Curcumin, a naturally occurring agent, has diversified beneficial roles including cytoprotection. Using human lens epithelial cells (hLECs) and Prdx6-deficient cells, we show the evidence that curcumin protects cells by upregulating Prdx6 transcription via invoking specificity protein 1 (Sp1) activity against proapoptotic stimuli. Curcumin enhanced Sp1 and Prdx6 mRNA and protein expression in a concentration-dependent manner, as evidenced by western and real-time PCR analyses, and thereby negatively regulated ROS-mediated apoptosis by blunting ROS expression and lipid peroxidation. Bioinformatic analysis and DNA–protein binding assays disclosed three active Sp1 sites (−19/27, −61/69 and −82/89) in Prdx6 promoter. Co-transfection experiments with Sp1 and Prdx6 promoter–chloramphenicol acetyltransferase (CAT) constructs showed that CAT activity was dramatically increased in LECs or Sp1-deficient cells (SL2). Curcumin treatment of LECs enhanced Sp1 binding to its sites, consistent with curcumin-dependent stimulation of Prdx6 promoter with Sp1 sites and cytoprotection. Notably, disruption of Sp1 sites by point mutagenesis abolished curcumin transactivation of Prdx6. Also, curcumin failed to activate Prdx6 expression in the presence of Sp1 inhibitors, demonstrating that curcumin-mediated increased expression of Prdx6 was dependent on Sp1 activity. Collectively, the study may provide a foundation for developing transcription-based inductive therapy to reinforce endogenous antioxidant defense by using dietary supplements.
reactive oxygen species; apoptosis; Prdx6; transcription factor; transactivation; cell survival
Various pharmacognostic parameters including macroscopy, microscopy, chemomicroscopy and behaviour of powdered drug on treatment with different chemical reagents were studied on the leaves of Bauhinia purpurea Linn. (Family Caesalpinaceae). Phytochemical screening of the plant part with various solvents revealed the presence of phenolic compounds, tannins, flavonoids, phytosterols, saponins and glycosides in it.
Effect of salinity (NaCl, 100 mM) on growth, nitrate reductase (NR) and glutamine synthetase (GS) activities, and uptake of NH4+ was studied in the wild type (WT) and the NaCl-tolerant mutant type (MT) of cyanobacterium Anabaena doliolum. Results obtained in the presence of salt showed significant reduction in the growth rate of both WT and MT cells of A. doliolum by about 77.8 and 40 %, respectively over without NaCl. Similarly rate of NR activity in both WT and MT strains was reduced by 45.5 and 44.5 %, respectively. On the contrary, rate of GS activity of both the WT and MT strains in the presence 100 mM of NaCl increased by 34 and 159 %, respectively. The results of this study indicate that tolerance to NaCl in A. doliolum is more dependent on NH4+ assimilation rather than on nitrate assimilation in relation to N-metabolism. The increased GS activity in MT cells of the cyanobacterium is possibly because of high rate of energy dependent NH4+ uptake.
Cyanobacteria; NaCl-Tolerant Mutant; NH4+ uptake; Nitrate reductase and Glutamine synthetase activity
The effect of methanolic extract of cashewnut (Anacardium occidentale) shell extract was seen on conidial germination of Erysiphe pisi and powdery mildew development in pea (Pisum sativum). Maximum conidial germination inhibition of E. pisi on glass slides was observed at 300 ppm. Similar effect on floated pea leaves was observed after 48 h at the same concentration. Conidial germination on intact untreated pea leaves was also assessed on II and IV nodal leaves while IV and II nodal leaves were treated with the extract and vice versa. There was tremendous reduction in conidial germination on all the nodal leaves. The disease intensity of pea powdery mildew was significantly reduced by methanolic extract of cashewnut shells. Maximum reduction was observed with 200 ppm where 39% disease intensity was recorded in comparison to 96.53% in the control. The phenolic acid content of pea leaves following treatments with this extract varied and no definite pattern was observed. Out of several phenolic compounds, namely, gallic, ferulic, chlorogenic, and cinnamic acids, only gallic acid was found to be present consistently in all the treatments with varied amounts.
Anacardium occidentale; Erysiphe pisi; Induced resistance; Pisum sativum
Our study aimed to obtain a comprehensive insight into the etiology of nephrotic syndrome in our patient population. We analyzed medical records of 290 patients with diagnosis of nephrotic syndrome as defined by International Study of Kidney Disease in Children (ISKDC), between January 1987 and December 2000, at the Sher-I-Kashmir Institute of Medical Sciences, Soura, Srinagar. Primary glomerular disease was found to be the most prevalent, accounting for 91.73% of all glomerular diseases. Among primary glomerular diseases, minimal change disease (MCD) was the most common histological lesion (43.79%). Most patients presented within 3 months duration (61.4%) and the most common symptom was puffiness of face (98.45%) followed by pedal edema (91%). Focal segmental glomerulosclerosis (FSGS) was the second most common lesion (16.89%) followed by membranous glomerulonephritis (GN) (13.4%) and membranoproliferative GN (11.72%). Amongst secondary glomerular diseases, diabetes mellitus was the most prevalent (4.48%), followed by lupus nephritis (3.1%). In conclusion, primary glomerular diseases constituted the most common group encountered and the prevalence of MCD was quite high with males, children and young adults. FSGS was associated with a high prevalence of end-stage renal disease (ESRD; 26.53%), hypertension (71.42%) and hematuria (81.63%).
Minimal change disease; nephrotic syndrome; focal segmental glomerulosclerosis; end stage kidney disease
Systemic effect of two plant growth-promoting rhizobacterial (PGPR) strains,viz., Pseudomonas fluorescens (Pf4) and P. aeruginosa (Pag), was evaluated on pea (Pisum sativum) against the powdery mildew pathogen Erysiphe pisi. Foliar spray of the two PGPR strains was done on specific nodal leaves of pea and conidial germination of E. pisi was observed on other nodal leaves,distal to the treated ones. Conidial germination was reduced on distant leaves and at the same time,specific as well as total phenolic compounds increased in the leaves distal to those applied with PGPR strains,thereby indicating a positive correlation. The strains induced accumulation of phenolic compounds in pea leaves and the amount increased when such leaves were get inoculated with E. pisi conidia. Between the two strains, Pag was found to be more effective than Pf4 as its effect was more persistent in pea leaves. Foliar application of PGPR strains for the control of powdery mildew of pea is demonstrated in vitro while correlating it with the increased accumulation of plant phenolics.
Erysiphe pisi; Foliar spray; Induced resistance; Pseudomonas aeruginosa; Pseudomonas fluorescens
The biological activity of the mineralocorticoid antagonist, spironolactone depend upon its metabolism. In this study the effect of diuretic drug compound spironolactone on the acid and alkaline phosphatase in the testes of albino rat. The drug spironolactone was administered orally daily for 7th, 14th and 21st days at the dose of 100 mg/kg body weight. Among them, the side effects of drug are that the degradation of alkaline phosphatase in the testes; while acid phosphatase increased significantly may be due to 7a-thiospironolactone is a tissue metabolite of spironolactone and may contribute to the testicular enzymes, therapeutic actions and some other side effects. It is suggested that the decrease and increase of alkaline and acid phosphatase in the testes of albino rat are the due to the side effects of spironolactone drug compound.
Drug Spironolactone; Albino rat; Acid and Alkaline Phosphatase
High performance liquid chromatographic (HPLC) analysis of mycelia of Sclerotium rolfsii grown in broth medium supplemented with garlic (Allium sativum) and onion (Allium cepa) was carried out to estimate qualitative and quantitative changes in phenolic acids. Several phenolic acids, such as gallic, chlorogenic, ferulic, o-coumaric and cinnamic acids were detected in varied amounts in mycelia grown on such media as compared to control. Phenolic acids represents a wide range of secondary metabolite found in the cells of plants and microbes including fungi. The growth characters of S. rolfsii in various supplements also varied from thin and transparent to thick and opaque.
Allium cepa; Allium sativum; Phenolic acids; Sclerotium rolfsii