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Jhunjhunwala, S.

Publications and source records attributed to Jhunjhunwala, S..

21 records · Page 2Linked to original sources

Antibacterial efficacy of Jackfruit rag extract against clinically important pathogens and validation of its antimicrobial activity in Shigella dysenteriae infected Drosophila melanogaster infection model

The aim of this study was to determine the antibacterial property of extract derived from a part of the Jackfruit called rag, that is generally considered as fruit waste. Morpho-physical characterization of the Jackfruit rag extract (JFRE) was performed using gas-chromatography, where peaks indicative of furfural; pentanoic acid; and hexadecanoic acid were observed. In vitro biocompatibility of JFRE was performed using the MTT assay, which showed comparable cellular viability between extract-treated and untreated mouse fibroblast cells. Agar well disc diffusion assay exhibited JFRE induced zones of inhibition for a wide variety of laboratory and clinical strains of gram-positive and gram-negative bacteria. Analysis of electron microscope images of bacterial cells suggests that JFRE induces cell death by disintegration of the bacterial cell wall and precipitating intracytoplasmic clumping. The antibacterial activity of the JFREs was further validated in vivo using Shigella dysenteriae infected fly model, where JFRE pre-fed flies infected with S. dysenteriae had significantly reduced mortality compared to controls. JFRE demonstrates broad antibacterial property, both in vitro and in vivo, possibly by its activity on bacterial cell wall. This study highlights the importance of exploring alternative sources of antibacterial compounds, especially from plant-derived waste, that could provide economical and effective solutions to current challenges in antimicrobial therapy.

microbiology↗

Transposable Element Expression In Tumors Is Associated With Immune Infiltration And Increased Antigenicity

Profound loss of DNA methylation is a well-recognized hallmark of cancer. Given its role in silencing transposable elements (TEs), we hypothesized that extensive TE expression occurs in tumors with highly demethylated DNA. We developed REdiscoverTE, a computational method for quantifying genome-wide TE expression in RNA sequencing data. Using The Cancer Genome Atlas database, we observed increased expression of over 400 TE subfamilies, of which 262 appeared to result from a proximal loss of DNA methylation. The most recurrent TEs were among the evolutionarily youngest in the genome, predominantly expressed from intergenic loci, and associated with antiviral or DNA damage responses. Treatment of glioblastoma cells with a demethylation agent resulted in both increased TE expression and de novo presentation of TE-derived peptides on MHC class I molecules. Therapeutic reactivation of tumor-specific TEs may synergize with immunotherapy by inducing both inflammation and the display of potentially immunogenic neoantigens.\n\nOne Sentence SummaryTransposable element expression in tumors is associated with increased immune response and provides tumor-associated antigens

cancer biology↗

Microtubule dynamics regulates mitochondrial fission

Mitochondria are organized as tubular networks in the cell and undergo fission and fusion. While several of the molecular players involved in mediating mitochondrial dynamics have been identified, the precise cellular cues that initiate fission or fusion remain largely unknown. In fission yeast, mitochondria are organized along microtubule bundles. Here, we employed deletions of kinesin-like proteins to perturb microtubule dynamics, and determined that cells with long microtubules exhibited long, but fewer mitochondria, whereas cells with short microtubules exhibited short, but several mitochondria due to reduced mitochondrial fission in the former and elevated fission in the latter. Correspondingly, upon onset of closed mitosis in fission yeast, wherein interphase microtubules assemble to form the spindle within the nucleus, we measured increased mitochondrial fission. We determined that the consequent rise in the mitochondrial copy number was necessary to reduce partitioning errors while stochastically partitioning mitochondria between daughter cells. We discovered that the association of mitochondria with microtubules physically impeded the assembly of the fission protein Dnm1 around mitochondria, resulting in inhibition of mitochondrial fission. Taken together, we demonstrate a novel mechanism for regulation of mitochondrial fission that is dictated by the interaction between mitochondria and the microtubule cytoskeleton.

cell biology↗