Jawaharlal Nehru University

About: Jawaharlal Nehru University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Population & Candida albicans. The organization has 6082 authors who have published 13455 publications receiving 245407 citations. The organization is also known as: JNU.

Mitochondria Influence CDR1 Efflux Pump Activity, Hog1-Mediated Oxidative Stress Pathway, Iron Homeostasis, and Ergosterol Levels in Candida albicans

Abstract: Mitochondrial dysfunction in Candida albicans is known to be associated with drug susceptibility, cell wall integrity, phospholipid homeostasis, and virulence. In this study, we deleted CaFZO1, a key component required during biogenesis of functional mitochondria. Cells with FZO1 deleted displayed fragmented mitochondria, mitochondrial genome loss, and reduced mitochondrial membrane potential and were rendered sensitive to azoles and peroxide. In order to understand the cellular response to dysfunctional mitochondria, genome-wide expression profiling of fzo1Δ/Δ cells was performed. Our results show that the increased susceptibility to azoles was likely due to reduced efflux activity of CDR efflux pumps, caused by the missorting of Cdr1p into the vacuole. In addition, fzo1Δ/Δ cells showed upregulation of genes involved in iron assimilation, in iron-sufficient conditions, characteristic of iron-starved cells. One of the consequent effects was downregulation of genes of the ergosterol biosynthesis pathway with a commensurate decrease in cellular ergosterol levels. We therefore connect deregulated iron metabolism to ergosterol biosynthesis pathway in response to dysfunctional mitochondria. Impaired activation of the Hog1 pathway in the mutant was the basis for increased susceptibility to peroxide and increase in reactive oxygen species, indicating the importance of functional mitochondria in controlling Hog1-mediated oxidative stress response. Mitochondrial phospholipid levels were also altered as indicated by an increase in phosphatidylserine and phosphatidylethanolamine and decrease in phosphatidylcholine in fzo1Δ/Δ cells. Collectively, these findings reinforce the connection between functional mitochondria and azole tolerance, oxidant-mediated stress, and iron homeostasis in C. albicans.

Phytosynthesis, Characterization and Fungicidal Potential of Emerging Gold Nanoparticles Using Pongamia pinnata Leave Extract: A Novel Approach in Nanoparticle Synthesis

Abstract: Biomediated synthesis of gold nanoparticles (AuNPs) using plant extract is a favorable alternative to traditional physicochemical based methods. Biological synthesis assists in the generation of stable and biocompatible nanoparticles (NPs). The aim of the present work was to fabricate AuNPs using Pongamia pinnata leave extract. The synthesized AuNPs were characterized by various analytical techniques such as UV–visible spectroscopy, TEM, EDX, and XRD. Absorption spectra showed SPR peaks in the range of 520–540 nm signifying the formation of AuNPs stabilized by P. pinnata extract. The average size of NPs was found in the range 10–25 nm as obtained from TEM analysis. Moreover, the synthesized NPs showed antifungal activity. The antifungal activities of AuNPs were tested against oomycetes SR1 and BP1120. The MIC80 value was observed at the concentrations 1.6 and 0.8 mg/mL of AuNPs in SR1 and BP1120 fungus, respectively. The study revealed an efficient, eco-friendly and simple method for synthesis of stable AuNPs using green synthetic approach.

A Novel Synthesis of the Graphene Oxide-Silver (GO-Ag) Nanocomposite for Unique Physiochemical Applications.

Abstract: Graphene oxide-silver nanocomposite (GO-Ag) was fabricated via the sonochemical method, which shows unique physiochemical properties. Graphene oxide (GO) and silver nanoparticles (AgNPs) were synthesized by modified Hummer's and Chemical reduction methods, respectively. The synthesized nanocomposite was characterized using powder X-ray diffraction, Raman spectroscopy, and Fourier-transform infrared spectroscopy. The surface morphology of synthesized nanoparticles was studied using scanning electron microscopy and transmission electron microscopy. The thermoluminescence property of the nanocomposite was analyzed by irradiating the samples in gamma radiation at 1 kGy. Electrochemical reversibility of the GO-Ag nanocomposite was examined by cyclic voltammetry. The photocatalytic application of the nanocomposite was studied using degradation of methylene blue dye. Results reveal that doping of AgNPs on the GO surface not only improves its dye degradation property but also enhances its thermoluminescence property. This knowledge will be helpful in determining the antibacterial property of the GO-Ag nanocomposite in the future.

Dietary-feeding of Grape Seed Extract Prevents Azoxymethane-induced Colonic Aberrant Crypt Foci Formation in Fischer 344 Rats

Abstract: Chemoprevention by dietary agents/supplements has emerged as a novel approach to control various malignancies, including colorectal cancer (CRC). This study assessed dietary grape seed extract (GSE) effectiveness in preventing azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation and associated mechanisms in Fischer 344 rats. Six-week-old rats were injected with AOM, and fed control diet or the one supplemented with 0.25% or 0.5% (w/w) GSE in pre- and post-AOM or only post-AOM experimental protocols. At 16 wk of age, rats were sacrificed and colons were evaluated for ACF formation followed by cell proliferation, apoptosis, and molecular analyses by immunohistochemistry. GSE-feeding caused strong chemopreventive efficacy against AOM-induced ACF formation in terms of up to 60% (P < 0.001) reduction in number of ACF and 66% (P < 0.001) reduction in crypt multiplicity. Mechanistic studies showed that GSE-feeding inhibited AOM-induced cell proliferation but enhanced apoptosis in colon including ACF, together with a strong decrease in cyclin D1, COX-2, iNOS, and survivin levels. Additional studies showed that GSE-feeding also decreased AOM-caused increase in beta-catenin and NF-kappaB levels in colon tissues. Compared to control animals, GSE alone treatment did not show any considerable change in these biological and molecular events in colon, and was nontoxic. Together, these findings show the chemopreventive efficacy of GSE against the early steps of colon carcinogenesis in rats via likely targeting of beta-catenin and NF-kappaB signaling, and suggest its potential usefulness for the prevention of human CRC.