Biology subjects

Gopal, V.

Publications and source records attributed to Gopal, V..

5 recordsLinked to original sources

bioRxiv2025

Zinc ions inactivate influenza virus hemagglutinin and prevent receptor binding

Influenza A viruses (IAV) cause seasonal flu and occasional pandemics. In addition, the potential for the emergence of new strains presents unknown challenges for public health. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of these viruses. Metal ions embedded into PPE have been demonstrated to inactivate respiratory viruses, but the underlying mechanism of inactivation and potential for resistance is presently not well understood. In this study, we found that zinc ions directly impact the binding of influenza virus to host cell sialic acid receptors using hemagglutination assays. Quantifying this effect, we observed that zinc ions inhibit IAV receptor binding within 1 minute of exposure in a concentration-dependent manner. Maximum inhibition was achieved within 1 hour and irreversible for at least 24 hours. Serial passaging of IAV in the presence of zinc did not result in resistance. Overall, these findings are in line with previous observations indicating that zinc-embedded materials impact the IAV hemagglutinin and SARS-CoV-2 spike proteins, and support work toward developing robust, passive, self-cleaning antiviral barriers in PPE.

microbiology↗

bioRxiv2024

Octopus can use odor plumes to find food

Odor-plume-guided navigation, tracking an odor plume to its source, is a primordial behavior used by most animals to search beyond the visual range. Here we report the first laboratory observations of octopuses performing this behavior, demonstrating that they can use odor plumes to find food. In a three-station discrimination task carried out in the dark, octopus showed a strong preference to move upstream towards the food-baited target, supporting the hypothesis that they are performing odor-guided search. When seeking a single baited target, also in the dark, octopuses not only preferred to move upstream towards the food source, but they also displayed characteristic motions associated with odor-gated rheotaxis, a commonly used odor tracking strategy used by many animals, which includes pausing, switchbacks, and across-stream redirections to the bait. Additionally, when approaching single baited stations the octopus often made reactive fast lunging motions. The observation of these fast arm-aligned motions (FAAM), taken together with the observation that the octopus did not have a characteristic body axis orientation to the bait, as would be expected if bilaterally symmetric organs such as the olfactory pits guided this behavior, supports the hypothesis that the suckers are the primary chemosensory organs driving octopus odor-guided behaviors.

animal behavior and cognition↗

bioRxiv2022

Enhancing adult neuroplasticity by epigenetic regulation of Parvalbumin-expressing GABAergic cells

Failure of inhibiting fear in response to harmless stimuli contributes to anxiety disorders. Extinction training only temporarily suppresses fear memories in adults, but it is highly effective in juveniles. GABAergic parvalbumin-positive (PV+) cells restrict plasticity in adult brains, thus increasing PV+ cell plasticity could promote the suppression of fear memories following extinction training in adults. Histone deacetylase 2 (Hdac2) restrains both structural and functional synaptic plasticity; however, whether and how Hdac2 controls adult PV+ cell plasticity is unknown. Here, we report that Hdac2 deletion or pharmacological inhibition in PV+ cells attenuate spontaneous recovery of fear memory after fear extinction learning in adults. These manipulations promote a temporally restricted downregulation of Acan, a critical perineuronal net component expressed exclusively by PV+ cells in medial prefrontal cortex. Finally, we show that Acan transient downregulation before extinction training but after fear memory acquisition is sufficient to reduce spontaneous fear memory recovery in wild-type mice.

neuroscience↗

bioRxiv2020

Zinc-embedded fabrics inactivate SARS-CoV-2 and influenza A virus

Infections with respiratory viruses can spread via liquid droplets and aerosols, and cause diseases such as influenza and COVID-19. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of respiratory droplets containing these viruses. However, influenza A viruses and coronaviruses are stable for hours on various materials, which makes frequent and correct disposal of these PPE important. Metal ions embedded into PPE may inactivate respiratory viruses, but confounding factors such as absorption of viruses make measuring and optimizing the inactivation characteristics difficult. Here we used polyamide 6.6 (PA66) fibers that had zinc ions embedded during the polymerisation process and systematically investigated if these fibers can absorb and inactivate pandemic SARS-CoV-2 and influenza A virus H1N1. We find that these viruses are readily absorbed by PA66 fabrics and inactivated by zinc ions embedded into this fabric. The inactivation rate (pfu{middle dot}gram-1{middle dot}min-1) exceeds the number of active virus particles expelled by a cough and supports a wide range of viral loads. Moreover, we found that the zinc content and the virus inactivating property of the fabric remain stable over 50 standardized washes. Overall, these results provide new insight into the development of "pathogen-free" PPE and better protection against RNA virus spread.

microbiology↗

bioRxiv2016

Delivery of BACE1 siRNA mediated by TARBP-BTP fusion protein reduces β-amyloid deposits in a transgenic mouse model of Alzheimers disease

Systemic delivery of nucleic acids to the central nervous system (CNS) is a major challenge for the development of RNA interference-based therapeutics due to absence of stability, target specificity, non-permeability to the blood-brain barrier (BBB), and mainly due to lack of suitable carriers. Using a designed bi-functional fusion protein TARBP-BTP, very recently we demonstrated knockdown of target genes in the brain of both A{beta}PP-PS1 (Alzheimers disease, AD) and wildtype C57BL/6 mice upon systemic delivery of a single dose of siRNA. In this report, we further substantiate this hypothesis through an extended study in A{beta}PP-PS1 mice, which upon treatment with seven doses of {beta}-secretase APP cleaving Enzyme 1 (BACE1) siRNA, led to target-specific effects in the mouse brain. Concomitant gene silencing and consequent reduction in plaque load in the cerebral cortex and hippocampus (>60%) in mice treated with TARBP-BTP:siRNA complex further led to improvement in spatial learning and memory, which was assessed and verified through Morris Water Maze test that revealed significant improvement in cognitive function. Moreover, the treatment did not induce any adverse effects as revealed by the histopathology of different organs. The work validates the efficiency of TARBP-BTP fusion protein as an efficient mediator of RNAi giving considerable scope for future intervention of neurodegenerative disorders of the CNS through the use of short nucleic acids as gene specific inhibitors.

neuroscience↗