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Parabens are synthetic antimicrobial compounds used as a preservative for extending the shelf life of food, pharmaceutical and cosmetic products. The alkyl chain length of the paraben esters positively correlates with their antimicrobial property. Hence, long-chain paraben esters, namely butylparaben and propylparaben, are used in combination as they have better solubility and antimicrobial efficacy. Extensive use of parabens has now resulted in the ubiquitous presence of these compounds in various human and environmental matrices. During early life, exposure to environmental contaminants is known to cause oxidative-stress mediated apoptosis in developing organs. The brain being one of the high oxygen-consuming, metabolically active and lipid-rich organ, it is primarily susceptible to reactive oxygen species (ROS) and lipid peroxidation (LP) induced neuronal cell death. The primary cause for the impairment in cognitive and emotional neurobehvioural outcomes in neurodegenerative disease was found to be associated with neuronal apoptosis. The present study aimed to study butylparaben and propylparaben's effect on zebrafish during early embryonic stages. Besides this, the association between alteration in anxiety-like neurobehavioral response with oxidative stress and antioxidant status in head region was also studied. The study results showed variation in the toxic signature left by butylparaben and propylparaben on developmental parameters such as hatching rate, survival and non-lethal malformations in a time-dependent manner. Data from the light-dark preference test showed embryonic exposure to butylparaben and propylparaben to trigger anxiety-like behavior in zebrafish larvae. In addition, a significant increase in intracellular ROS and LP levels correlated with suppressed antioxidant enzymes: superoxide dismutases (SOD), catalases (CAT), Glutathione peroxidase (GPx), glutathione S-transferase (GST), and Glutathione (GSH) activity in the head region of the zebrafish larvae. Acetylcholinesterase (AChE) activity was also suppressed in the exposed groups, along with increased nitric oxide production. The overall observations show increased oxidative stress indices correlating with upregulated expression of apoptotic cells in a dose-dependent manner. Collectively, our findings reveal butylparaben and propylparaben as an anxiogenic neuroactive Christy Lite, Ajay Guru, and Melita Juliet contributed equally to this study.

Severe acute respiratory syndrome, coronavirus 2 (SARS-CoV-2), remains to be a threat across the globe. SARS-CoV-2 entry to the host-mediated by binding of viral spike protein to the Human angiotensin-converting enzyme 2 (ACE2) receptor. ACE2 is an essential member of the Renin-Angiotensin system (RAS) involved in maintaining blood pressure and vascular remodelling. Although ACE2 receptor is the entry point to the host, recent studies show activation of ACE2 to modulate the host to develop a suitable environment for its replication. However, the ACE2 activating the immune signals on SARS-CoV-2 attachment is still under investigation. We have used a systems biological approach to construct the host regulatory network upon SARS-CoV-2 attachment to the ACE2 receptor. Since lungs are the primary infection site, we integrate human lung gene expression profile along with the host regulatory network to demonstrate the altered host signalling mechanism on viral infection. Further, the network was functionally enriched to determine immune modulation in the network. We also used the proteomic database to assess the occurrence of similar signalling events in other human tissue that exhibits lineage of infection across different organs. The constructed network contains 133 host proteins with 298 interactions that directly or indirectly connect to the ACE2 receptor. Among 133 proteins, 29 found to be differentially regulated in the host lungs on SARS-CoV-2 infection. Altered proteins connect multiple proteins in a network that modulates kinase, carboxypeptidase and cytokine activity, leading to change in the host immune system, cell cycle, and signal transduction mechanism. Further investigation showed the presence of similar signalling events in the kidney, placenta, pancreas, testis, stomach, small intestine and adrenal gland suggesting the possible the mechanistic lineage of viral infection in other tissue. Overall, our results will help advance our understanding of the immune molecular regulatory network influenced by the ACE2 mediated interaction in other body tissues, which could help in finding the secondary health complications associated with SARS-CoV-2 infection.

The recent advances in the field of aquaculture over the last decade has helped the cultured-fish industry production sector to identify problems and choose the best approaches to achieve high-volume production. Understanding the emerging roles of non-coding RNA (ncRNA) in the regulation of fish physiology and health will assist in gaining knowledge on the possible applications of ncRNAs for the advancement of aquaculture. There is information available on the practical considerations of epigenetic mechanisms like DNA methylation, histone modification and ncRNAs, such as microRNA in aquaculture, for both fish and shellfish. Among the non-coding RNAs, PIWI-interacting RNA (piRNA) is 24-31 bp long transcripts, which is primarily involved in silencing the germline transposons. Besides, the burgeoning reports and studies establish piRNAs' role in various aspects of biology. Till date, there are no reviews that summarize the recent findings available on piRNAs in animal models, especially on piRNAs biogenesis and biological action. To gain a better understanding and get an overview on the process of piRNA genesis among the different animals, this work reviews the literature available on the processes of piRNA biogenesis in animal models with special reference to aquatic animal model zebrafish. This review also presents a short discussion and prospects of piRNA's application in relevance to the aquaculture industry.

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