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Biology subjects

Saini, V.

Publications and source records attributed to Saini, V..

9 recordsLinked to original sources

Male Age and Sexual Maturity: Lipopolysaccharide-induced tumor necrosis factor influences sperm quality and reproduction in Anopheles culicifacies

Elucidating the biological and molecular mechanisms that govern male fertility and mating behavior in mosquitoes is critical for optimizing genetic and sterile insect technique-based vector control strategies. Here, we examined age-related changes in male reproductive capacity in Anopheles culicifacies, using female egg output as an indirect indicator of male fertility. Our results demonstrated that male reproductive age follows a non-linear pattern of fertility. Morphometric analysis from emergence to day 13 post-eclosion revealed a strong correlation between seminal vesicle capacity and female fecundity, suggesting that age-dependent gonadal development directly influences reproductive potential. At the molecular level, we identified AcLITAF6 as a key regulator of male reproductive homeostasis. RNAi-mediated knockdown of AcLITAF6 impaired apoptosis-associated and phagocytic clearance, reduced sperm viability, and decreased female productive outcomes. Conclusively, we reveal a previously unrecognized role of LITAF in sperm quality control and male reproductive fitness, highlighting AcLITAF6 as a potential target for mosquito population suppression strategies.

developmental biology↗

Molecular identification and functional analysis of HrpZ2, a new member of harpin superfamily from Pseudomonas syringae inducing hypersensitive response in tobacco.

Harpins belong to a group of proteins with distinctive features such as heat stability, glycine richness, and absence of cysteine, and are secreted by many Gram-negative phytopathogens via the type III secretion system. Harpins are known to trigger hypersensitive response followed by induction of systemic acquired resistance in non-host plants. However, the molecular mechanism of harpin-induced hypersensitive response remained largely unexplored, mainly because of lack of structural information. In this study, we report the cloning of a new harpin gene (hrpZ2) from Pseudomonas syringae strain MTCC-11950, belonging to the harpin superfamily. In silico analysis revealed that about 50.29% of the protein consists of alpha-helices, 48.53% are random coils, and only 1.16% are beta-sheets, and nearly half (42%) of the protein consists of intrinsically disordered regions. Based on a prokaryotic predictive model and the presence of a signal peptide on its N-terminus, the subcellular localization of harpin is predicted as extracellular. To date, no experimentally determined crystal structure of any harpin protein is available. Therefore, we built and validated a three-dimentional model (with 99% of residues in allowed/additionally allowed regions and a Z-score of -5.3) of harpin. Phylogenetic analysis and functional domain studies revealed that this new harpin belongs to the harpin superfamily. Infiltration of harpin in tobacco leaves resulted in hypersensitive response, which was associated with oxidative burst, callose deposition, localized cell death, and increased activity of defense-related enzymes such as phenylalanine ammonia-lyase and polyphenol oxidase. Furthermore, infiltration of harpin in non-host plants from different angiosperm families induced hypersensitive response, indicating broad-spectrum agricultural applicability of this new harpin protein. This study elucidates the molecular and functional properties of the new harpin protein and its ability to induce hypersensitive response across a broad range of non-host plants.

plant biology↗

Epstein-Barr virus and Helicobacter pylori Coinfection Drives Gut and Brain Barrier Dysfunction

Biological barriers, including blood-brain barrier (BBB) and gut epithelial barrier, are essential to maintain homeostasis and provide protection against pathogenic stress. Here, we investigated the impact of Helicobacter pylori-Epstein Barr Virus coinfection on gut-brain axis integrity. Our results demonstrate that coinfection induces significant disruptions in tight and adherens junction (TJ and AJ respectively) proteins in gastric epithelial cells, including downregulation of ZO-1 and E-cadherin. The secretome from these coinfected cells significantly compromises the integrity of BBB-derived endothelial cells, including cleavage of VE-cadherin, loss of TJ proteins such as Claudin-5, and enhanced permeability. Furthermore, the sole exposure of mice to coinfected secretome lead to the loss of cerebral VE-cadherin and ZO-1 and the induction of neuroinflammation, characterized by elevated pro-inflammatory cytokines, TNF-, amyloidogenic accumulation, and neurocognitive deficits. The secretome driving such forces potentially carries pathogenic metabolites, host inflammatory cytokines and metabolites that might contribute to disease pathogenesis as observed in this study. Together, our current study provides novel insights into how coinfections contribute to gut-brain axis dysregulation and neurological pathogenesis. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=174 SRC="FIGDIR/small/655045v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@138ca23org.highwire.dtl.DTLVardef@15eccc4org.highwire.dtl.DTLVardef@d588c6org.highwire.dtl.DTLVardef@106a485_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG

microbiology↗

Sensory Appendage Protein triggers alarm to pyrethroid in Indian malarial vector Anopheles culicifacies

Sensory appendage proteins (SAPs) serve as molecular arms of odorant-binding protein family members and mediate chemical communication from the external to the internal environment of the insect body. We recently reported that SAP members might have an important role in blood-feeding and/or insecticide resistance-associated behavioral physiologies, but the mechanism remains unclear. Here we show how SAP contributes (i) to the host attraction during navigation for blood-feeding, and (ii) triggers an alert via integrated actions of eyes and peripheral sensory organs to circumvent the toxic effect of insecticide in the susceptible strain of An. culicifacies. Among the six identified SAP members, AcSAP1 and AcSAP2 are abundantly expressed in the olfactory and legs, and their expression is significantly modulated at night in naive adult female mosquitoes. We noticed that AcSAP1 silencing significantly impairs the host-attraction properties of the mosquitoes. Its strong binding affinity to the synthetic pyrethroid prompted us to evaluate the AcSAP1 response to insecticide exposure. Confocal microscopy and molecular profiling data reveal a heightened modulation in the expression of AcSAP1 in eyes, and other peripheral sensory organs including the olfactory (****p<0.00001), legs (**p < 0.004), wings (***p < 0.0004). These findings collectively suggest a crucial role of AcSAP1 in facilitating mosquito navigation, and/or insecticide avoidance. Unraveling the basis of SAP interactions with peripheral sensory systems could pave the way for the development of novel vector control tools.

animal behavior and cognition↗

Sentences, Words, Attention: A "Transforming" Aphorism of miRNA Discovery

Discovering pre-miRNAs is the core of miRNA discovery. Using traditional sequence/structural features many tools have been published to discover miRNAs. However, in practical applications like genomic annotations, their actual performance has been far away from acceptable. This becomes more grave in plants where unlike animals pre-miRNAs are much more complex and difficult to identify. This is reflected by the huge gap between the available software for miRNA discovery and species specific miRNAs information for animals and plants. Here, we present miWords, an attention based genomic language processing transformer and context scoring deep-learning approach, with an optional sRNA-seq guided CNN module to accurately identify pre-miRNA regions in plant genomes. During a comprehensive bench-marking the transformer part of miWords alone significantly outperformed the compared published tools with consistent performance while breaching accuracy of 98% across a large number of experimentally validated data. Performance of miWords was also evaluated across Arabidopsis genome where also miWords, even without using its sRNA-seq reads module, outperformed those software which essentially require sRNA-seq reads to identify miRNAs. miWords was run across the Tea genome, reporting 803 pre-miRNA regions, all validated by sRNA-seq reads from multiple samples, and 10 randomly selected cases re-validated by qRT-PCR.

bioinformatics↗

Mycobacterium tuberculosis H2S functions as a sink to modulate central metabolism, bioenergetics, and drug susceptibility

H2S is a potent gasotransmitter in eukaryotes and bacteria. Host-derived H2S has been shown to profoundly alter M. tuberculosis (Mtb) energy metabolism and growth. However, compelling evidence for endogenous production of H2S and its role in Mtb physiology is lacking. We show that multidrug-resistant and drug-susceptible clinical Mtb strains produce H2S, whereas H2S production in non-pathogenic M. smegmatis is barely detectable. We identified Rv3684 (Cds1) as an H2S-producing enzyme in Mtb and show that cds1 disruption reduces, but does not eliminate, H2S production, suggesting the involvement of multiple genes in H2S production. We identified endogenous H2S to be an effector molecule that maintains bioenergetic homeostasis by stimulating respiration primarily via cytochrome bd. Importantly, H2S plays a key role in central metabolism by modulating the balance between oxidative phosphorylation and glycolysis, and functions as a sink to recycle sulfur atoms back to cysteine to maintain sulfur homeostasis. Lastly, Mtb-generated H2S regulates redox homeostasis and susceptibility to anti-TB drugs clofazimine and rifampicin. These findings reveal previously unknown facets of Mtb physiology and have implications for routine laboratory culturing, understanding drug susceptibility, and improved diagnostics.

microbiology↗

A Stacked ensemble method for forecasting influenza-like illness visit volumes at emergency departments

Accurate and reliable short-term forecasts of influenza-like illness (ILI) visit volumes at the emergency departments can improve staffing and resource allocation decisions in each hospital. In this paper, we developed a stacked ensemble model that averages the predictions from various competing methodologies in the current frontier for ILI-related forecasts. We also constructed a back-of-the-envelope prediction interval for the stacked ensemble, which provides a conservative characterization of the uncertainty in the stacked ensemble predictions. We assessed the reliability and accuracy of our models 1 to 4 weeks ahead forecasts using real-time hospital-level data on weekly ILI visit volumes during the 2012-2018 flu seasons in the Alberta Childrens Hospital, located in Calgary, Alberta, Canada. Over this time period, our models prediction deviated from the realized ILI visit volume by an average of 12% for 1 week ahead forecasts, with a 90% prediction interval having coverage rates ranging from 90.7 to 97.7%.

bioinformatics↗

Treatment-shortening effect of a novel regimen combining high-dose rifapentine and clofazimine in pathologically distinct mouse models of tuberculosis

High-dose rifapentine and clofazimine have each separately been associated with treatment-shortening activity when incorporated into tuberculosis (TB) treatment regimens. We hypothesized that both modifications, i.e., the addition of clofazimine and the replacement of rifampin with high-dose rifapentine, in the first-line regimen for drug-susceptible TB would significantly shorten the duration of treatment necessary for cure. We tested this hypothesis in a well-established BALB/c mouse model of TB chemotherapy and also in a C3HeB/FeJ mouse model in which mice can develop caseous necrotic lesions, an environment where rifapentine and clofazimine may individually be less effective. In both mouse models, replacing rifampin with high-dose rifapentine and adding clofazimine in the first-line regimen resulted in greater bactericidal and sterilizing activity than either modification alone, suggesting that a rifapentine- and clofazimine-containing regimen may have the potential to significantly shorten the treatment duration for drug-susceptible TB. These data provide preclinical evidence supporting the evaluation of regimens combining high-dose rifapentine and clofazimine in clinical trials.

microbiology↗

Activity of a long-acting injectable bedaquiline formulation in a paucibacillary mouse model of latent tuberculosis infection

The potent anti-tuberculosis activity and long half-life of bedaquiline make it an attractive candidate for long-acting/extended release formulations for treatment of latent tuberculosis infection (LTBI). Our objective was to evaluate a long-acting injectable (LAI) bedaquiline formulation in a validated paucibacillary mouse model of LTBI. Following immunization with Mycobacterium bovis rBCG30, BALB/c mice were challenged by aerosol infection with M. tuberculosis H37Rv. Treatment began 13 weeks after challenge infection with one of the following regimens: untreated negative control; positive controls of daily rifampin (10 mg/kg), once-weekly rifapentine (15 mg/kg) and isoniazid (50 mg/kg), or daily bedaquiline (25 mg/kg); test regimens of one, two, or three monthly doses of LAI bedaquiline at 160 mg/dose (BLAI-160); and test regimens of daily bedaquiline at 2.67 (B2.67), 5.33 (B5.33), or 8 (B8) mg/kg to deliver the same total bedaquiline as one, two, or three doses of BLAI-160, respectively. All drugs were administered orally, except for BLAI-160 (intramuscular injection). The primary outcome was the decline in M. tuberculosis lung CFU counts during 12 weeks of treatment. The negative and positive control regimens performed as expected. One, two, and three doses of BLA-160 resulted in decreases of 2.9, 3.2, and 3.5 log10 CFU/lung, respectively by week 12. Daily oral dosing with B2.67, B5.33, and B8 decreased lung CFU counts by 1.6, 2.8, and 4.1 log10, respectively. One dose of BLAI-160 exhibited activity for at least 12 weeks. The sustained activity of BLAI-160 indicates promise as a short-course LTBI treatment requiring few patient encounters to ensure treatment completion.

microbiology↗