Understanding Genetic Risks: Computational Exploration of Human ß-Synuclein nsSNPs and their Potential Impact on Structural Alteration.

Synucleins are pivotal in neurodegenerative conditions. Beta-synuclein (ß-synuclein) is part of the synuclein protein family alongside alpha-synuclein (α-synuclein) and gamma-synuclein (γ-synuclein). These proteins, found mainly in brain tissue and cancers, are soluble and unstructured. ß-synuclein shares significant similarity with α-synuclein, especially in their N-terminus, with a 90% match. However, their aggregation tendencies differ significantly. While α-synuclein aggregation is believed to be counteracted by ß-synuclein, which occurs in conditions like Parkinson's disease, ß-synuclein may counteract α-synuclein's toxic effects on the nervous system, offering potential treatment for neurodegenerative diseases. Under normal circumstances, ß-synuclein may guard against disease by interacting with α-synuclein. Yet, in pathological environments with heightened levels or toxic substances, it might contribute to disease. Our research aims to explore potential harmful mutations in the ß-synuclein using computational tools to predict their destabilizing impact on protein structure. Consensus analysis revealed rs1207608813 (A63P), rs1340051870 (S72F), and rs1581178262 (G36C) as deleterious. These findings highlight the intricate relationship between nsSNPs and protein function, shedding light on their potential implications in disease pathways. Understanding the structural consequences of nsSNPs is crucial for elucidating their role in pathogenesis and developing targeted therapeutic interventions. Our results offer a robust computational framework for identifying neurodegenerative disorder-related mutations from SNP datasets, potentially reducing the costs associated with experimental characterization.

Molecular dynamics simulations assisted investigation of phytochemicals as potential lead candidates against anti-apoptotic Bcl-B protein.

Due to the multifarious nature of cancer, finding a single definitive cure for this dreadful disease remains an elusive challenge. The dysregulation of the apoptotic pathway or programmed cell death, governed by the Bcl-2 family of proteins plays a crucial role in cancer development and progression. Bcl-B stands out as a unique anti-apoptotic protein from the Bcl-2 family that selectively binds to Bax which inhibits its pro-apoptotic function. Although several inhibitors are reported for Bcl-2 family proteins, no specific inhibitors are available against the anti-apoptotic Bcl-B protein. This study aims to address this research gap by using virtual screening of an in-house library of phytochemicals from seven anti-cancer medicinal plants to identify lead molecules against Bcl-B protein. Through pharmacokinetic analysis and molecular docking studies, we identified three lead candidates (Enterolactone, Piperine, and Protopine) based on appreciable drug-likeliness, ADME properties, and binding affinity values. The identified molecules also exhibited specific interactions with critical amino acid residues of the binding cleft, highlighting their potential as lead candidates. Finally, molecular dynamics simulations and MM/PBSA based binding free energy analysis revealed that Enterolactone (CID_114739) and Piperine (CID_638024) molecules were on par with Obatoclax (CID_11404337), which is a known inhibitor of the Bcl-2 family proteins.Communicated by Ramaswamy H. Sarma.

Shedding light on structure, function and regulation of human sirtuins: a comprehensive review.

Sirtuins play an important role in signalling pathways associated with various metabolic regulations. They possess mono-ADP-ribosyltransferase or deacylase activity like demalonylase, deacetylase, depalmitoylase, demyristoylase and desuccinylase activity. Sirtuins are histone deacetylases which depends upon nicotinamide adenine dinucleotide (NAD) that deacetylate lysine residues. There are a total of seven human sirtuins that have been identified namely, SIRT1, SIRT2, SIRT3, SIRT4, SIRT5, SIRT6 and SIRT7. The subcellular location of mammalian sirtuins, SIRT1, SIRT6, and SIRT7 are in the nucleus; SIRT3, SIRT4, and SIRT5 are in mitochondria, and SIRT2 is in cytoplasm. Structurally sirtuins contains a N-terminal, a C-terminal and a Zn+ binding domain. The sirtuin family has been found to be crucial for maintaining lipid and glucose homeostasis, and also for regulating insulin secretion and sensitivity, DNA repair pathways, neurogenesis, inflammation, and ageing. Based on the literature, sirtuins are overexpressed and play an important role in tumorigenicity in various types of cancer such as non-small cell lung cancer, colorectal cancer, etc. In this review, we have discussed about the different types of human sirtuins along with their structural and functional features. We have also discussed about the various natural and synthetic regulators of sirtuin activities like resveratrol. Our overall study shows that the correct regulation of sirtuins can be a good target for preventing and treating various diseases for improving the human lifespan. To investigate the true therapeutic potential of sirtuin proteins and their efficacy in a variety of pathological diseases, a better knowledge of the link between the structure and function of sirtuin proteins would be necessary.

Isolation, characterisation, anticancer and anti-oxidant activities of 2-methoxy mucic acid from Rhizophora apiculata: an in vitro and in silico studies.

The main objective of the present study is to isolate and characterise the novel bioactive molecule, 2-methoxy mucic acid (4) from Rhizophora apiculate Blume under the Rhizophoraceae family. In this study, the 2-methoxy mucic acid (4) was isolated for the first time from the methanolic extract of the leaves of R. apiculata. Anticancer activity of 2-methoxy mucic acid (4) was evaluated against HeLa and MDA-MB-231 cancer cell lines and they displayed promising activity with IC50 values of 22.88283 ± 0.72 µg/ml in HeLa and 2.91925 ± 0.52 µg/ml in the case of MDA-MB-231, respectively. Furthermore, the antioxidant property of 2-methoxy mucic acid (4) was found to be (IC50) 21.361 ± 0.41 µg/ml. Apart from in vitro studies, we also performed extensive in silico studies (molecular docking and molecular dynamics simulation) on four critical antiapoptotic Bcl-2 family members (Bcl-2, Bcl-w, Bcl-xL and Bcl-B) towards 2-methoxy mucic acid (4). The results revealed that this molecule showed higher binding affinity towards Bcl-B protein (ΔG = -5.8 kcal/mol) and the structural stability of this protein was significantly improved upon binding of this molecule. The present study affords vital insights into the importance of 2-methoxy mucic acid (4) from R. apiculata. Furthermore, it opens the therapeutic route for the discovery of anticancer drugs. Research HighlightsThis is a first report on a bioactive compound identified and characterised; a novel 2-methoxy mucic acid derived from methanolic crude extract from the leaves of R. apiculata from ANI.Estimated binding free energy of 2-methoxy mucic acid is found to be -5.8 kcal/mol to the anti-apoptotic Bcl-B protein.2-methoxy mucic acid showed both significant anti-cancer and anti-oxidant activity.Communicated by Ramaswamy H. Sarma.

Isolation and biological evaluation 7-hydroxy flavone from Avicennia officinalis L: insights from extensive in vitro, DFT, molecular docking and molecular dynamics simulation studies.

The flavonoid based 7-hydroxy flavone (PubChem CID: 5281894; molecular formula: C15H10O3) molecule has been isolated for the first time from the methanolic extract from the leaves of Avicennia officinalis L. in the tropical mangrove ecosystem of Andaman and Nicobar Islands (ANI), India. The molecular structure of bioactive compound was characterized by spectroscopic analysis, including FT-IR, 1H, 13C NMR spectroscopy and ESI-HRMS and elucidated as 7-hydroxy flavone. An anticancer activity of isolated 7-hydroxy flavone was evaluated by in vitro study against two different human cancer cell lines namely, HeLa (cervical cells) and MDA-MB231 (breast cells) and they exhibited promising anticancer activity with IC50 values are 22.5602 ± 0.21 µg/mL and 3.86474 ± 0.35 µg/mL, respectively. The antioxidant property of 7-hydroxy flavone at a standard concentration of 50 µg, was found to be (IC50) 5.5486 ± 0.81 µg/mL. In summary, this investigation provides evidence that 7-hydroxy flavone exhibits both anticancer and antioxidant properties. Meanwhile, the antimicrobial activity ability of 7-hydroxy flavone were also evaluated using three Gram positive and two Gram negative strain exhibited no antimicrobial activities. Density-functional theory (DFT) studies confirm the structure is global minima in the PES, from the optimized geometry FMO and MESP map analyzed. Further, the molecular docking and molecular dynamics simulation studies result shows that 7-hydroxy flavone has the better binding ability with anti-apoptotic Bcl-2 protein with the estimated free energy of binding of -6.3 kcal/mol. This bioactive compound may be act as drug candidate for treating various kinds of cancers. HighlightsA 7-hydroxy flavone molecule has been isolated from Avicennia officinalis.The isolated pure compound was subjected to spectral analysis such as FT-IR, 1H NMR, 13C NMR spectral data and HRMS analysis for skeleton of the molecule.The anticancer activity of 7-hydroxy flavone studied against Cervical (HeLa) cancer cell lines and breast (MDA-MB231) cancer cell lines with the IC50 values of 22.5602 ± 0.21 µg/mL and 3.86474 ± 0.35 µg/mL), respectively.The antioxidant properties of 7-hydroxy flavone were found to be (IC50) 5.5486 ± 0.81 µg/mL at a standard concentration of 50 µg.DFT, molecular docking and MD simulation results explained that 7-hydroxy flavone could be the most promising candidate to inhibit the function of anti-apoptotic Bcl-2 protein in cancerous cell.Communicated by Ramaswamy H. Sarma.

Heterologous expression of hAID in E. coli leads to the production of a splice isoform of AID: hAIDδC, a mystery to be explored.

Activation-induced cytidine deaminase (AID) is a key player that initiates antibody diversification in activated B-cell. AID mediates somatic hypermutation (SHM) and class switch recombination (CSR) via the deamination of cytosine to uracil at the Ig locus, resulting in the production of high-affinity antibodies. AID is predominantly restricted to Ig genes, whereas off-targeting of AID leads to lymphocyte-related malignancies. Interestingly, apart from FL-AID other splice isoforms of AID are highly expressed in the lymphocyte malignancies. In our study, we found that the heterologous expression of hAID-FL in E. coli cells produced two induced bands of hAID as demonstrated by SDS-PAGE and western blotting. Remarkably, peptide mapping data predicted that one band is hAID-FL and the other is its splice isoform, hAIDδE4a. To get an insight into why E. coli cells expressed hAID-FL and hAID variant, we mutated the 5' and 3' splice site of a putative intron of hAID, but it failed to produce only hAID-FL. Incidentally, hAID expressed with fusion partners also displayed two bands, and peptide mapping data strongly suggest that besides hAID-FL, the lower band showed a significant number of amino acids missing towards the C-terminal domain (named as hAIDδC). Our results are the first report to show that expression of recombinant hAID alone or irrespective of solubilization tags in E. coli cells produced hAID-FL and hAIDδC. It will be fascinating to explore the potential mechanism underlying the expression of hAIDδC from recombinant hAID plasmid in E. coli cells.

A computational essential dynamics approach to investigate structural influences of ligand binding on Papain like protease from SARS-CoV-2.

Papain like protease (PLpro) is a cysteine protease from the coronaviridae family of viruses. Coronaviruses possess a positive sense, single-strand RNA, leading to the translation of two viral polypeptides containing viral structural, non-structural and accessory proteins. PLpro is responsible for the cleavage of nsp1-3 from the viral polypeptide. PLpro also possesses deubiquitinating and deISGlyating activity, which sequesters the virus from the host's immune system. This indispensable attribute of PLpro makes it a protein of interest as a drug target. The present study aims to analyze the structural influences of ligand binding on PLpro. First, PLpro was screened against the ZINC-in-trials library, from which four lead compounds were identified based on estimated binding affinity and interaction patterns. Next, based on molecular docking results, ZINC000000596945, ZINC000064033452 and VIR251 (control molecule) were subjected to molecular dynamics simulation. The study evaluated global and essential dynamics analyses utilising principal component analyses, dynamic cross-correlation matrix, free energy landscape and time-dependant essential dynamics to predict the structural changes observed in PLpro upon ligand binding in a simulated environment. The MM/PBSA-based binding free energy calculations of the two selected molecules, ZINC000000596945 (-41.23 ± 3.70 kcal/mol) and ZINC000064033452 (-25.10 ± 2.65 kcal/mol), displayed significant values which delineate them as potential inhibitors of PLpro from SARS-CoV-2.

Anti-T-Lymphocyte Immunoglobulin (Grafalon) as an Induction Agent for Renal Transplantation: A Real-World, Retrospective, Single-Center Experience.

OBJECTIVES: Polyclonal antithymocyte globulins are widely used in the induction regimens of solid-organ transplant recipients; however, their doses and outcomes remain to be standardized in Indian patients. We report our clinical experience from the real-world use of Grafalon (an anti-T-lymphocyte globulin; ATG-Fresenius) as an induction agentin renal transplant recipients from India. MATERIALS AND METHODS: In this retrospective, single- center, observational study, we analyzed the medical records of 177 consecutive, kidney-only transplant recipients who received induction therapy with Grafalon from September 2016 to March 2018 at our center. Incidences of biopsy-proven acute rejection and graft dysfunction, immunosuppression protocol, Grafalon dosage, 18-month post-transplant graft and patient survival, treatment-related adverse events, and infective complications were reported. RESULTS: Mean age of patients was 41.46 years (range, 14-68 years), (85% were males). The average dose of Grafalon was 5.81 ± 1.95 mg/kg (range, 2.41 to 10.07 mg/kg). Graft dysfunction (ie, at least 20% increase in serum creatinine from baseline) was observed in 26 patients (14%): 11 patients (6.2%) had biopsy-proven acute rejections, 11 patients (6.2%) had acute tubular necrosis, and 4 patients (2.2%) had calcineurin inhibitor toxicity. Seven deaths were recorded: 2 each from fungal pneumonia, bacterial pneumonia, and acute coronary syndrome and 1 with urinary tract infection with septicemia. Death-censored graft survival was 100% at 12 months and 98% at 18-month follow-up; overall patient survival was 96%. Infective complications occurred in 40 patients (22.5%), with the most common being urinary tract infection in 32 patients (18%). No malignancies were reported. CONCLUSIONS: Use of a potent induction therapy like anti-T-lymphocyte globulin (Grafalon) is often restricted by the risk of side effects and lack of local clinical evidence supporting its role in long-term graft survival. Real-world evidence support the safe and effective use of anti-T-lymphocyte globulin as an induction agent in renal transplant recipients with an individualized dosing approach.

Dimeric assembly of human Suv3 helicase promotes its RNA unwinding function in mitochondrial RNA degradosome for RNA decay.

Human Suv3 is a unique homodimeric helicase that constitutes the major component of the mitochondrial degradosome to work cooperatively with exoribonuclease PNPase for efficient RNA decay. However, the molecular mechanism of how Suv3 is assembled into a homodimer to unwind RNA remains elusive. Here, we show that dimeric Suv3 preferentially binds to and unwinds DNA-DNA, DNA-RNA, and RNA-RNA duplexes with a long 3' overhang (≥10 nucleotides). The C-terminal tail (CTT)-truncated Suv3 (Suv3ΔC) becomes a monomeric protein that binds to and unwinds duplex substrates with ~six to sevenfold lower activities relative to dimeric Suv3. Only dimeric Suv3, but not monomeric Suv3ΔC, binds RNA independently of ATP or ADP, and is capable of interacting with PNPase, indicating that dimeric Suv3 assembly ensures its continuous association with RNA and PNPase during ATP hydrolysis cycles for efficient RNA degradation. We further determined the crystal structure of the apo-form of Suv3ΔC, and SAXS structures of dimeric Suv3 and PNPase-Suv3 complex, showing that dimeric Suv3 caps on the top of PNPase via interactions with S1 domains, and forms a dumbbell-shaped degradosome complex with PNPase. Overall, this study reveals that Suv3 is assembled into a dimeric helicase by its CTT for efficient and persistent RNA binding and unwinding to facilitate interactions with PNPase, promote RNA degradation, and maintain mitochondrial genome integrity and homeostasis.

A Liver Damage Prediction Using Partial Differential Segmentation with Improved Convolutional Neural Network.

Background: The liver is one of the most significant and most essential organs in the human body. It is divided into two granular lobes, one on the right and one on the left, connected by a bile duct. The liver is essential in the removal of waste products from human food consumption, the creation of bile, the regulation of metabolic activities, the cleaning of the blood by sensitizing digestive management, and the storage of vitamins and minerals. To perform the classification of liver illnesses using computed tomography (CT scans), two critical phases must first be completed: liver segmentation and categorization. The most difficult challenge in categorizing liver disease is distinguishing the liver from the other organs near it. Methodology. Liver biopsy is a kind of invasive diagnostic procedure, widely regarded as the gold standard for accurately estimating the severity of liver disease. Noninvasive approaches for examining liver illnesses, such as blood serum markers and medical imaging (ultrasound, magnetic resonance MR, and CT) have also been developed. This approach uses the Partial Differential Technique (PDT) to separate the liver from the other organs and Level Set Methodology (LSM) for separating the cancer location from the surrounding tissue based on the projected pictures used as input. With the help of an Improved Convolutional Classifier, the categorization of different phases may be accomplished. Results: Several accuracies, sensitivity, and specificity measurements are produced to assess the categorization of LSM using an Improved Convolutional classifier. Approximately, 97.5% of the performance accuracy of the liver categorization is achieved with a 94.5% continuous interval (CI) of [0.6775 1.0000] and an error rate of 2.1%. The suggested method's performance is compared to that of two existing algorithms, and the sensitivity and specificity provide an overall average of 96% and 93%, respectively, with 95% Continuous Interval of [0.7513 1.0000] and [0.7126 1.0000] for sensitivity and specificity, respectively.

A comprehensive in silico and in vitro studies on quinizarin: a promising phytochemical derived from Rhizophora mucronata Lam.

Mangrove plants are a great source of phytomedicines, since from the beginning of human civilization and the origin of traditional medicines. In the present study, ten different mangrove leaf methanolic extracts were screened for the type of phytochemicals followed by assessing antimicrobial, anti-oxidant and anti-cancer activities. The efficient methanolic crude extract of Rhizospora mucornata was further purified and characterized for the presence of the bioactive compound. Based on UV-visible spectroscopy, FTIR, NMR and HRMS analysis, the bioactive compound was 1,4-dihydroanthraquinone; also termed as Quinizarin. This identified compound was potential in exhibiting antimicrobial, antioxidant, and cytotoxic activity. Quinizarin inhibited the growth of Bacillus cereus and Klebsiella aerogenes with minimum inhibitory concentration (MIC) of 0.78 and 1.5 mg/ml. The DPPH free radical scavenging assay revealed the maximum activity of 99.8% at the concentration of 200 µg/ml with an IC50 value of 12.67 ± 0.41 µg/ml. Cytotoxic assay against HeLa (cervical) and MDA-MB231(breast) cancer cell lines revealed IC50 values to be 4.60 ± 0.26 and 3.89 ± 0.15 µg/ml. Together the results of molecular docking and molecular dynamics simulation studies explained that Quinizarin molecule showed stronger binding affinity (-6.2 kcal/mol) and significant structural stability towards anti-apoptotic Bcl-2 protein. Thus, the study put forth the promising role of the natural molecule - Quinizarin isolated from R. mucornata in the formulation of therapeutic drugs against bacterial infections and cancer. Communicated by Ramaswamy H. Sarma.

Biological evaluation of gallic acid and quercetin derived from Ceriops tagal: insights from extensive in vitro and in silico studies.

Gallic acid (PubChem CID: 370) and quercetin (PubChem CID: 5280343) are major phenolic compounds in many mangrove plants that have been related to health cure. In the present study, the active fractions namely gallic acid (1) and quercetin (2) were isolated from the methanolic extract of leaves of Ceriops tagal in a Tropical mangrove ecosystem of Andaman and Nicobar Island (ANI), India. The chemical structures were determined by spectroscopic analysis: Fourier-Transform Infrared spectroscopy (FT-IR), 1H, 13C Nuclear Magnetic Resonance (NMR) spectroscopy, and High-resolution mass spectrometry (HRMS). The anticancer activity of isolated compounds (1) and (2) were evaluated by in vitro assays against two human cancer cell lines namely, HeLa (Cervical) and MDA-MB231 (Breast) cancer cells revealed that IC50 values of gallic acid (HeLa: 4.179197 ± 0.45 µg/ml; MDA-MB231: 80.0427 ± 0.19 µg/ml at 24 h) and quercetin (HeLa: 99.914 ± 0.18 µg/ml; MDA-MB231: 18.288382 ± 0.12 µg/ml at 24 h), respectively. Antioxidant properties of gallic acid (1) and quercetin (2) are found to be IC50 value of 0.77 ± 0.41 µg/ml and 1.897 ± 0.81 µg/ml, respectively. Molecular docking results explained that gallic acid (1) and quercetin (2) showed estimated binding free energy (ΔG) of -5.4 and -6.9 kcal/mol towards drug target Bcl-B protein, respectively. The estimated inhibition constant (Ki) for these two molecules are 110 and 8.75 µM, respectively. The MD simulation additionally supported that quercetin molecule is significantly improved the structural stability of Bcl-B protein. The present study provides key insights about the importance of polyphenols, and thus leads to open the therapeutic route for anti-cancer drug discovery process.Communicated by Ramaswamy H. Sarma.

Experimental and computational investigation on the binding of anticancer drug gemcitabine with bovine serum albumin.

This study reports the experimental and computational investigation on the binding of a common anticancer drug, gemcitabine, with the model plasma protein, bovine serum albumin (BSA). Several experimental and computational methods, such as intrinsic and synchronous fluorescence, UV-visible, and circular dichroism spectroscopies, consensus molecular docking and molecular dynamics simulation have been employed to elucidate the binding mechanism. Gemcitabine altered the UV-visible spectrum of BSA, which is a clear indication of the complex formation between them. The visual inspection of observed fluorescence quenching results at λex = 280 nm and 295 nm has shown the substantial involvement of tyrosine residue, even larger than tryptophan. However, after the correction of inner filter effect of the observed data, it became clear that tyrosine has a negligible role in quenching. A 20-fold decrease in quenching constant was found in the corrected data, as compared to the observed data at λex = 280 nm. There was a 1:1 weak binding between BSA and gemcitabine accompanied by dynamic quenching. The secondary structure of BSA remained almost intact in the presence of gemcitabine. The primary binding site of gemcitabine inside BSA was the drug binding site 2 or DS II, which is located in the subdomain 3 A. MD Simulation results suggested that gemcitabine doesn't affect or deviate the structure of BSA upon interaction throughout 100 ns time period. The dominating intermolecular forces were hydrophobic forces and hydrogen bonding. A small change in the frontier molecular orbitals of gemcitabine was also observed after its binding with BSA.Communicated by Ramaswamy H. Sarma.

Identifying the natural compound Catechin from tropical mangrove plants as a potential lead candidate against 3CLpro from SARS-CoV-2: An integrated in silico approach.

SARS-CoV-2, a member of beta coronaviruses, is a single-stranded, positive-sense RNA virus responsible for the COVID-19 pandemic. With global fatalities of the pandemic exceeding 4.57 million, it becomes crucial to identify effective therapeutics against the virus. A protease, 3CLpro, is responsible for the proteolysis of viral polypeptides into functional proteins, which is essential for viral pathogenesis. This indispensable activity of 3CLpro makes it an attractive target for inhibition studies. The current study aimed to identify potential lead molecules against 3CLpro of SARS-CoV-2 using a manually curated in-house library of antiviral compounds from mangrove plants. This study employed the structure-based virtual screening technique to evaluate an in-house library of antiviral compounds against 3CLpro of SARS-CoV-2. The library was comprised of thirty-three experimentally proven antiviral molecules extracted from different species of tropical mangrove plants. The molecules in the library were virtually screened using AutoDock Vina, and subsequently, the top five promising 3CLpro-ligand complexes along with 3CLpro-N3 (control molecule) complex were subjected to MD simulations to comprehend their dynamic behaviour and structural stabilities. Finally, the MM/PBSA approach was used to calculate the binding free energies of 3CLpro complexes. Among all the studied compounds, Catechin achieved the most significant binding free energy (-40.3 ± 3.1 kcal/mol), and was closest to the control molecule (-42.8 ± 5.1 kcal/mol), and its complex with 3CLpro exhibited the highest structural stability. Through extensive computational investigations, we propose Catechin as a potential therapeutic agent against SARS-CoV-2. Communicated by Ramaswamy H. Sarma.

Recombinant organophosphorus hydrolase (OPH) expression in E. coli for the effective detection of organophosphate pesticides.

Accumulation and exposure of organophosphate pesticides are of great concern today owing to their abundant usage and potential health hazards. Harmful effects of organophosphate pesticide exposure and limitations of the available treatment methods necessitate the development of reliable, selective, cost-effective, and sensitive methods of detection. We developed a novel biosensor based on the enzymatic action of recombinant organophosphorus hydrolase (OPH) expressed in E. coli. We report the development of colorimetric biosensors made of His-Nus-OPH as well as His-Nus-OPH loaded alginate microspheres. The colorimetric detection method developed using solution-phase and alginate-encapsulated His-Nus-OPH exhibited detection limits of 0.045 and 0.039 mM, respectively, for ethyl paraoxon, and 0.101 and 0.049 mM, respectively, for methyl parathion. Additionally, fluorescence measurement using pH-sensitive fluorescein isothiocyanate (FITC) was used to sense the quantity of organophosphorus pesticides. The fluorometric detection method using solution-phase His-Nus-OPH, with ethyl paraoxon and methyl parathion as the substrate, reveals the lower limit of detection as 0.014 mM and 0.044 mM, respectively. Our results demonstrate the viability of His-Nus-OPH for OP detection with good sensitivity, LOD, and linear range. We report the first use of N-terminal His-NusA-tagged OPH, which enhances solubility significantly and presents a significant advance for the scientific community.

Impact of ophthalmic webinars on the resident's learning experience during COVID-19 pandemic: An insight into its present and future prospects.

PURPOSE: To analyze the impact of ophthalmic webinars on the resident's learning experience during the COVID-19 pandemic (CP). METHODS: This cross-sectional nationwide study was carried out for 1 month during CP and included a total of 382 ophthalmic residents. A questionnaire was sent through various social media platforms. RESULTS: Residents expressed a decline in their clinical exposure (74%; 220), thesis work (58%; 218), and acquisition of the knowledge and skills (42.5%; 161) during CP. Benefits of webinars as perceived by the residents included gain in additional knowledge (77%; 286), feedback on queries (56%; 209), access to multiple speakers (50%; 191), and topics (30%; 110). Nearly 75% (291) of residents endorsed webinars as good to the very good academic tool, and 54% (202) preferred to continue attending webinars in the post-CP phase. However, connectivity/download/data issues (54%; 200) followed by loss of personal touch (53%; 188), lengthy or irrelevant topic (37%; 134), and poor transmission quality (33%; 121) were major deterrents against the webinar. CONCLUSION: The current study generated overall mixed responses from the ophthalmic postgraduate residents in favor of webinars. In the present format, webinars bear enormous potentials to supplement the traditional learning tools by providing uninterrupted learning experiences. However, they are still limited by their pedagogical and technical issues.

Vitamin D3-VDR-PTPN6 axis mediated autophagy contributes to the inhibition of macrophage foam cell formation.

Macrophage derived foam cells in atherosclerotic plaques are the major factor responsible for the pathogenesis of atherosclerosis (AS). During advanced AS, macrophage-specific macroautophagy/autophagy is dysfunctional. 1, 25-dihydroxy vitamin D3 (VitD3) and its receptor VDR (vitamin D receptor) are reported to inhibit foam cell formation and induce autophagy; however, the role of VitD3-VDR-induced autophagy and foam cell formation in AS has not been explored. Here we find that VitD3 significantly recovered oxidized low-density lipoprotein-impaired autophagy, as well as increased autophagy-mediated lipid breakdown in mouse bone marrow-derived macrophages and human monocyte-derived macrophages, thus inhibiting the conversion of macrophages into foam cells. Importantly, VitD3 functions through its receptor VDR to upregulate autophagy and attenuate the accumulation of lipids in macrophages. Moreover, this study is the first occasion to report the interesting link between VitD3 signaling and PTPN6/SHP-1 (protein tyrosine phosphatase non-receptor type 6) in macrophages. VitD3-induced autophagy was abrogated in the presence of the PTPN6/Ptpn6 shRNA or inhibitor. VDR along with RXRA (retinoid X receptor alpha), and NCOA1 (nuclear receptor coactivator 1), are recruited to a specific response element located on the gene promoter and induce PTPN6 expression. PTPN6 contributes to VitD3-mediated autophagy by regulating autophagy-related genes via activation of MAPK1 (mitogen-activated protein kinase 1) and CEBPB (CCAAT enhancer binding protein beta). Furthermore, expression of PTPN6 is also crucial for VitD3-mediated inhibition of macrophage foam cell formation through autophagy. Thus, VitD3-VDR-PTPN6 axis-regulated autophagy attenuates foam cell formation in macrophages.

Targeting SARS-CoV-2: a systematic drug repurposing approach to identify promising inhibitors against 3C-like proteinase and 2'-O-ribose methyltransferase.

The recent pandemic associated with SARS-CoV-2, a virus of the Coronaviridae family, has resulted in an unprecedented number of infected people. The highly contagious nature of this virus makes it imperative for us to identify promising inhibitors from pre-existing antiviral drugs. Two druggable targets, namely 3C-like proteinase (3CLpro) and 2'-O-ribose methyltransferase (2'-O-MTase) were selected in this study due to their indispensable nature in the viral life cycle. 3CLpro is a cysteine protease responsible for the proteolysis of replicase polyproteins resulting in the formation of various functional proteins, whereas 2'-O-MTase methylates the ribose 2'-O position of the first and second nucleotide of viral mRNA, which sequesters it from the host immune system. The selected drug target proteins were screened against an in-house library of 123 antiviral drugs. Two promising drug molecules were identified for each protein based on their estimated free energy of binding (ΔG), the orientation of drug molecules in the active site and the interacting residues. The selected protein-drug complexes were then subjected to MD simulation, which consists of various structural parameters to equivalently reflect their physiological state. From the virtual screening results, two drug molecules were selected for each drug target protein [Paritaprevir (ΔG = -9.8 kcal/mol) & Raltegravir (ΔG = -7.8 kcal/mol) for 3CLpro and Dolutegravir (ΔG = -9.4 kcal/mol) and Bictegravir (ΔG = -8.4 kcal/mol) for 2'-OMTase]. After the extensive computational analysis, we proposed that Raltegravir, Paritaprevir, Bictegravir and Dolutegravir are excellent lead candidates for these crucial proteins and they could become potential therapeutic drugs against SARS-CoV-2. Communicated by Ramaswamy H. Sarma.