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1.
Daru ; 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39026019

ABSTRACT

BACKGROUND: COVID-19 pandemic has turned our world upside down by meddling with our normal lives. While there is no definitive drug against SARS-CoV-2, antiviral drugs that are already in the market, are being repurposed against it, could now complete long-term as well as all age-specific investigations, and they are successful in saving millions of lives. Nevertheless, side-effects are emergingly seen in the patients undergoing treatment, and ineffectiveness is increasingly found due to the emerging notorious variants of the virus. Many of them are also facing serious co-infections including black fungus, Zika, and H1N1 virus to name a few. OBJECTIVES: Therefore, this review highlights both drug resistance, their side-effects, and the significance for proper and long-term clinical trials of all age groups including children. METHODS: We have explored and proposed the mechanisms of drug resistance that may arise due to the misuse or overuse of drugs based on available experimental reports. RESULTS: The review provides solutions to the aforesaid issues of drug-resistance and side-effects by providing combination therapies, ancillary treatments, and other preventive strategies that can be useful in preventing drawbacks thereby curbing COVID-19 or similar future infections to maintain our normal lives. CONCLUSION: COVID-19 and its long-term effects, if any, can be eradicated with strategic and mindful use of related therapeutics in a controlled manner.

2.
Adv Protein Chem Struct Biol ; 140: 381-417, 2024.
Article in English | MEDLINE | ID: mdl-38762276

ABSTRACT

Cardiovascular disease (CVD) and cancer are major contributors to global morbidity and mortality. This book chapter delves into the intricate relationship between the immune system and the pathogenesis of both cardiovascular and cancer diseases, exploring the roles of innate and adaptive immunities, immune regulation, and immunotherapy in these complex conditions. The innate immune system acts as the first line of defense against tissue damage and infection, with a significant impact on the initiation and progression of CVD and cancer. Endothelial dysfunction, a hallmark in CVD, shares commonalities with the tumor microenvironment in cancer, emphasizing the parallel involvement of the immune system in both conditions. The adaptive immune system, particularly T cells, contributes to prolonged inflammation in both CVD and cancer. Regulatory T cells and the intricate balance between different T cell subtypes influence disease progression, wound healing, and the outcomes of ischemic injury and cancer immunosurveillance. Dysregulation of immune homeostasis can lead to chronic inflammation, contributing to the development and progression of both CVD and cancer. Thus, immunotherapy emerged as a promising avenue for preventing and managing these diseases, with strategies targeting immune cell modulation, cytokine manipulation, immune checkpoint blockade, and tolerance induction. The impact of gut microbiota on CVD and cancer too is explored in this chapter, highlighting the role of gut leakiness, microbial metabolites, and the potential for microbiome-based interventions in cardiovascular and cancer immunotherapies. In conclusion, immunomodulatory strategies and immunotherapy hold promise in reshaping the landscape of cardiovascular and cancer health. Additionally, harnessing the gut microbiota for immune modulation presents a novel approach to prevent and manage these complex diseases, emphasizing the importance of personalized and precision medicine in healthcare. Ongoing research and clinical trials are expected to further elucidate the complex immunological underpinnings of CVD and cancer thereby refining these innovative approaches.


Subject(s)
Cardiovascular Diseases , Neoplasms , Humans , Neoplasms/immunology , Neoplasms/therapy , Cardiovascular Diseases/immunology , Immunotherapy , Immunity, Innate/immunology , Gastrointestinal Microbiome/immunology , Animals , Adaptive Immunity/immunology
3.
Adv Protein Chem Struct Biol ; 139: 221-261, 2024.
Article in English | MEDLINE | ID: mdl-38448136

ABSTRACT

Bioinformatics is an interconnected subject of science dealing with diverse fields including biology, chemistry, physics, statistics, mathematics, and computer science as the key fields to answer complicated physiological problems. Key intention of bioinformatics is to store, analyze, organize, and retrieve essential information about genome, proteome, transcriptome, metabolome, as well as organisms to investigate the biological system along with its dynamics, if any. The outcome of bioinformatics depends on the type, quantity, and quality of the raw data provided and the algorithm employed to analyze the same. Despite several approved medicines available, cardiovascular disorders (CVDs) and cancers comprises of the two leading causes of human deaths. Understanding the unknown facts of both these non-communicable disorders is inevitable to discover new pathways, find new drug targets, and eventually newer drugs to combat them successfully. Since, all these goals involve complex investigation and handling of various types of macro- and small- molecules of the human body, bioinformatics plays a key role in such processes. Results from such investigation has direct human application and thus we call this filed as translational bioinformatics. Current book chapter thus deals with diverse scope and applications of this translational bioinformatics to find cure, diagnosis, and understanding the mechanisms of CVDs and cancers. Developing complex yet small or long algorithms to address such problems is very common in translational bioinformatics. Structure-based drug discovery or AI-guided invention of novel antibodies that too with super-high accuracy, speed, and involvement of considerably low amount of investment are some of the astonishing features of the translational bioinformatics and its applications in the fields of CVDs and cancers.


Subject(s)
Cardiovascular Diseases , Neoplasms , Humans , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/genetics , Neoplasms/drug therapy , Neoplasms/genetics , Algorithms , Antibodies , Computational Biology
4.
Int J Biol Macromol ; 254(Pt 2): 127898, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37939768

ABSTRACT

The ADP ribosylation factor like protein 15 (ARL15) gene encodes for an uncharacterized GTPase associated with rheumatoid arthritis (RA) and other metabolic disorders. Investigation of the structural and functional attributes of ARL15 is important to position the protein as a potential drug target. Using spectroscopy, we demonstrated that ARL15 exhibits properties inherent of GTPases. The Km and Vmax of the enzyme were calculated to be 100 µM and 1.47 µmole/min/µL, respectively. The equilibrium dissociation constant (Kd) of GTP binding with ARL15 was estimated to be about eight-fold higher than that of GDP. Small Angle X-ray Scattering (SAXS) data indicated that in solution, the apo state of monomeric ARL15 adopts a shape characterized by a globe of maximum linear dimension (Dmax) of 6.1 nm, and upon binding to GTP or GDP, the vector distribution profile changes to peak-n-tail shoulder with Dmax extended to 7.6 and 7.7 nm, respectively. Structure restoration using a sequence-based template and experimental SAXS data provided the first visual insight revealing that the folded N-terminal in the unbound state of the protein may toggle open upon binding to guanine nucleotides. The conformational dynamics observed in the N-terminal region offer a scope to develop drugs that target this unique GTPase, potentially providing treatments for a range of metabolic disorders.


Subject(s)
Arthritis, Rheumatoid , Metabolic Diseases , Humans , Guanine Nucleotides , Nucleotides/metabolism , Guanine , Scattering, Small Angle , X-Ray Diffraction , ADP-Ribosylation Factors/genetics , ADP-Ribosylation Factors/metabolism , Proteins/metabolism , Guanosine Triphosphate/metabolism , Guanosine Diphosphate
5.
Crit Rev Food Sci Nutr ; : 1-18, 2023 Jun 23.
Article in English | MEDLINE | ID: mdl-37350746

ABSTRACT

Clinical, epidemiological, and molecular studies have sufficiently highlighted the vitality of vitamin D [25(OH)D and 1,25(OH)2D] in human health and wellbeing. Globally, vitamin D deficiency (VDD) has become a public health concern among all age groups. There is a very high prevalence of VDD per the estimates from several epidemiological studies on different ethnic populations. But, population-specific scales do not support these estimates to define VDD clinically and consistent genetic associations. However, clinical studies have shown the relevance of serum vitamin D screening and oral supplementation in improving health conditions, pointing toward a more prominent role of vitamin D in health and wellness. Routinely, the serum concentration of vitamin D is measured to determine the deficiency and is correlated with physiological conditions and clinical symptoms. Recent research points toward a more inclusive role of vitamin D in different disease pathologies and is not just limited to otherwise bone health and overall growth. VDD contributes to the natural history of systemic ailments, including cardiovascular and systemic immune diseases. Considering its significant impact on premature morbidity and mortality, there is a compelling need to comprehensively review and document the direct and indirect implications of VDD in immune system deregulation, systemic inflammatory conditions, and cardio-metabolism. The recommendations from this review call for furthering our research concerning vitamin D and its direct and indirect implications.

6.
J Cell Biochem ; 124(6): 889-906, 2023 06.
Article in English | MEDLINE | ID: mdl-37192271

ABSTRACT

The unobtrusive cold environmental temperature can be linked to the development of cancer. This study, for the first time, envisaged cold stress-mediated induction of a zinc finger protein 726 (ZNF726) in breast cancer. However, the role of ZNF726 in tumorigenesis has not been defined. This study investigated the putative role of ZNF726 in breast cancer tumorigenic potency. Gene expression analysis using multifactorial cancer databases predicted overexpression of ZNF726 in various cancers, including breast cancer. Experimental observations found that malignant breast tissues and highly aggressive MDA-MB-231 cells showed an elevated ZNF726 expression as compared to benign and luminal A type (MCF-7), respectively. Furthermore, ZNF726 silencing decreased breast cancer cell proliferation, epithelial-mesenchymal transition, and invasion accompanied by the inhibition of colony-forming ability. Concordantly, ZNF726 overexpression significantly demonstrated opposite outcomes than ZNF726 knockdown. Taken together, our findings propose cold-inducible ZNF726 as a functional oncogene demonstrating its prominent role in facilitating breast tumorigenesis. An inverse correlation between environmental temperature and total serum cholesterol was observed in the previous study. Furthermore, experimental outcomes illustrate that cold stress elevated cholesterol content hinting at the involvement of the cholesterol regulatory pathway in cold-induced ZNF726 gene regulation. This observation was bolstered by a positive correlation between the expression of cholesterol-regulatory genes and ZNF726. Exogenous cholesterol treatment elevated ZNF726 transcript levels while knockdown of ZNF726 decreased the cholesterol content via downregulating various cholesterol regulatory gene expressions (e.g., SREBF1/2, HMGCoR, LDLR). Moreover, an underlying mechanism supporting cold-driven tumorigenesis is proposed through interdependent regulation of cholesterol regulatory pathway and cold-inducible ZNF726 expression.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/metabolism , Cell Line, Tumor , Carcinogenesis/genetics , Cholesterol/metabolism , Zinc Fingers , Epithelial-Mesenchymal Transition/genetics , Cell Movement , Gene Expression Regulation, Neoplastic , Cell Proliferation/genetics , MCF-7 Cells
7.
J Biomol Struct Dyn ; 41(10): 4253-4271, 2023 Jul.
Article in English | MEDLINE | ID: mdl-35446232

ABSTRACT

COVID-19 patients have shown overexpressed serum levels of several pro-inflammatory cytokines, leading to a high mortality rate due to numerous complications. Also, previous studies demonstrated that the metronidazole (MTZ) administration reduced pro-inflammatory cytokines and improved the treatment outcomes for inflammatory disorders. However, the effect and mechanism of action of MTZ on cytokines have not been studied yet. Thus, the current study aimed to identify anti-cytokine therapeutics for the treatment of COVID-19 patients with cytokine storm. The interaction of MTZ with key cytokines was investigated using molecular docking studies. MTZ-analogues, and its structurally similar FDA-approved drugs were also virtually screened against interleukin-12 (IL-12). Moreover, their mechanism of inhibition regarding IL-12 binding to IL-12 receptor was investigated by measuring the change in volume and area. IL-12-metronidazole complex is found to be more stable than all other cytokines under study. Our study also revealed that the active sites of IL-12 are inhibited from binding to its target, IL-12 receptor, by modifying the position of the methyl and hydroxyl functional groups in MTZ. Three MTZ analogues, metronidazole phosphate, metronidazole benzoate, 1-[1-(2-Hydroxyethyl)-5-nitroimidazol-2-yl]-N-methylmethanimine-oxide, and two FDA-approved drugs acyclovir (ACV), and tetrahydrobiopterin (THB) were also found to prevent binding of IL-12 to IL-12 receptor similar to MTZ by changing the surface and volume of IL-12 upon IL-12-drug/ligand complex formation. According to the RMSD results, after 100 ns MD simulations of human IL-12-MTZ/ACV/THB drug complexes, it was also observed that each complex was swinging within a few Å compared to their corresponding docking poses, indicating that the docking poses were reliable. The current study demonstrates that three FDA-approved drugs, namely, metronidazole, acyclovir and tetrahydrobiopterin, are potential repurposable treatment options for overexpressed serum cytokines found in COVID-19 patients. Similar approach is also useful to develop therapeutics against other human disorders.Communicated by Ramaswamy H. Sarma.


Subject(s)
COVID-19 , Metronidazole , Humans , Metronidazole/pharmacology , Metronidazole/therapeutic use , Metronidazole/chemistry , Interleukin-12 , Molecular Docking Simulation , Cytokines
8.
NPJ Parkinsons Dis ; 8(1): 66, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35650269

ABSTRACT

Parkinson's disease (PD) is a neurological disorder that affects the movement of the human body. It is primarily characterized by reduced dopamine levels in the brain. The causative agent of PD is still unclear but it is generally accepted that α-synuclein has a central role to play. It is also known that gap-junctions and associated connexins are complicated structures that play critical roles in nervous system signaling and associated misfunctioning. Thus, our current article emphasizes how, alongside α-synuclein, ion-channels, gap-junctions, and related connexins, all play vital roles in influencing multiple metabolic activities of the brain during PD. It also highlights that ion-channel and gap-junction disruptions, which are primarily mediated by their structural-functional changes and alterations, have a role in PD. Furthermore, we discussed available drugs and advanced therapeutic interventions that target Parkinson's pathogenesis. In conclusion, it warrants creating better treatments for PD patients. Although, dopaminergic replenishment therapy is useful in treating neurological problems, such therapies are, however, unable to control the degeneration that underpins the disease, thereby declining their overall efficacy. This creates an additional challenge and an untapped scope for neurologists to adopt treatments for PD by targeting the ion-channels and gap-junctions, which is well-reviewed in the present article.

10.
J Biomol Struct Dyn ; 40(20): 10454-10469, 2022.
Article in English | MEDLINE | ID: mdl-34229570

ABSTRACT

One major obstacle in designing a successful therapeutic regimen to combat COVID-19 pandemic is the frequent occurrence of mutations in the SARS-CoV-2 resulting in patient to patient variations. Out of the four structural proteins of SARS-CoV-2 namely, spike, envelope, nucleocapsid and membrane, envelope protein governs the virus pathogenicity and induction of acute-respiratory-distress-syndrome which is the major cause of death in COVID-19 patients. These effects are facilitated by the viroporin (ion-channel) like activities of the envelope protein. Our current work reports metagenomic analysis of envelope protein at the amino acid sequence level through mining all the available SARS-CoV-2 genomes from the GISAID and coronapp servers. We found majority of mutations in envelope protein were localized at or near PDZ binding motif. Our analysis also demonstrates that the acquired mutations might have important implications on its structure and ion-channel activity. A statistical correlation between specific mutations (e.g. F4F, R69I, P71L, L73F) with patient mortalities were also observed, based on the patient data available for 18,691 SARS-CoV-2-genomes in the GISAID database till 30 April 2021. Albeit, whether these mutations exist as the cause or the effect of co-infections and/or co-morbid disorders within COVID-19 patients is still unclear. Moreover, most of the current vaccine and therapeutic interventions are revolving around spike protein. However, emphasizing on envelope protein's (1) conserved epitopes, (2) pathogenicity attenuating mutations, and (3) mutations present in the deceased patients, as reported in our present study, new directions to the ongoing efforts of therapeutic developments against COVID-19 can be achieved by targeting envelope viroporin.


Subject(s)
COVID-19 , SARS-CoV-2 , Viroporin Proteins , Humans , COVID-19/mortality , COVID-19/virology , Mutation , SARS-CoV-2/genetics , Viroporin Proteins/genetics
11.
J Biomol Struct Dyn ; 40(24): 14067-14083, 2022.
Article in English | MEDLINE | ID: mdl-34784490

ABSTRACT

COVID-19, for which no confirmed therapeutic agents are available, has claimed over 48,14,000 lives globally. A feasible and quicker method to resolve this problem may be 'drug repositioning'. We investigated selected FDA and WHO-EML approved drugs based on their previously promising potential as antivirals, antibacterials or antifungals. These drugs were docked onto the nsp12 protein, which reigns the RNA-dependent RNA polymerase activity of SARS-CoV-2, a key therapeutic target for coronaviruses. Docked complexes were reevaluated using MM-GBSA analysis and the top three inhibitor-protein complexes were subjected to 100 ns long molecular dynamics simulation followed by another round of MM-GBSA analysis. The RMSF plots, binding energies and the mode of physicochemical interaction of the active site of the protein with the drugs were evaluated. Suramin, Penciclovir, and Anidulafungin were found to bind to nsp12 with similar binding energies as that of Remdesivir, which has been used as a therapy for COVID-19. In addition, recent experimental evidences indicate that these drugs exhibit antiviral efficacy against SARS-CoV-2. Such evidence, along with the significant and varied physical interactions of these drugs with the key viral enzyme outlined in this investigation, indicates that they might have a prospective therapeutic potential in the treatment of COVID-19 as monotherapy or combination therapy with Remdesivir.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Anidulafungin , Suramin , Molecular Docking Simulation , Antiviral Agents/chemistry
12.
Phytomedicine ; 92: 153753, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34610528

ABSTRACT

BACKGROUND: Medicinal plants or herbs produce a bounty of bioactive phytochemicals. These phytochemicals can influence a variety of physiological events related to cardiovascular health through multiple underlying mechanisms, such as their role as antioxidative, anti-ischemic, anti-proliferative, hypotensive, anti-thrombotic, and anti-hypercholesterolemic agents. PURPOSE: The purpose of this review is to summarize and connect evidences supporting the use of phytotherapy in the management of some of the most common cardiovascular impairments, molecular mechanisms underlying cardio-protection mediated by herbs, and clinical studies which are positively linked with the use of herbs in cardiovascular biology. Additionally, we also describe several adverse effects associated with some of the herbal plants and their products to provide a balanced set of studies in favor or against phytotherapy in cardiovascular health that may help global discourses on this matter. METHODS: Studies relating to the use of medicinal plants were mined by strategically searching scientific databases including Google Scholar, PubMed and Science Direct. Investigations involving approximately 175 articles including reviews, research articles, meta-analyses, and cross-sectional and observational studies were retrieved and analyzed in line with the stated purpose of this study. RESULTS: A positive correlation between the use of medicinal plants and cardiovascular health was observed. While maintaining cardiovascular physiology, medicinal plants and their derivatives seem to govern a variety of cellular mechanisms involved in vasoconstriction and vasorelaxation, which in turn, are important aspects of cardiovascular homeostasis. Furthermore, a variety of studies including clinical trials, cross-sectional studies, and meta-analyses have also supported the anti-hypertensive and thus, cardio-protective effects, of medicinal plants. Apart from this, evidence is also available for the potential drawbacks of several herbs and their products indicating that the unsupervised use of many herbs may lead to severe health issues. CONCLUSIONS: The cardio-protective outcomes of medicinal plants and their derivatives are supported by ever-increasing studies, while evidences exist for the potential drawbacks of some of the herbs. A balanced view about the use of medicinal plants and their derivative in cardiovascular biology thus needs to be outlined by researchers and the medical community. The novelty and exhaustiveness of the present manuscript is reflected by the detailed outline of the molecular basis of "herbal cardio-protection", active involvement of several herbs in ameliorating the cardiovascular status, adverse effects of medicinal plants, and the clinical studies considering the use of phytotherapy, all on a single platform.


Subject(s)
Plants, Medicinal , Antioxidants , Cross-Sectional Studies , Observational Studies as Topic , Phytochemicals/pharmacology , Phytotherapy
13.
J Am Soc Mass Spectrom ; 32(7): 1618-1630, 2021 Jul 07.
Article in English | MEDLINE | ID: mdl-34121407

ABSTRACT

Coronavirus (CoV) nonstructural proteins (nsps) assemble to form the replication-transcription complex (RTC) responsible for viral RNA synthesis. nsp7 and nsp8 are important cofactors of the RTC, as they interact and regulate the activity of RNA-dependent RNA polymerase and other nsps. To date, no structure of the full-length SARS-CoV-2 nsp7:nsp8 complex has been published. The current understanding of this complex is based on structures from truncated constructs, with missing electron densities, or from related CoV species where SARS-CoV-2 nsp7 and nsp8 share upward of 90% sequence identity. Despite available structures solved using crystallography and cryo-EM representing detailed static snapshots of the nsp7:nsp8 complex, it is evident that the complex has a high degree of structural plasticity. However, relatively little is known about the conformational dynamics of the individual proteins and how they complex to interact with other nsps. Here, the solution-based structural proteomic techniques, hydrogen-deuterium exchange mass spectrometry (HDX-MS) and cross-linking mass spectrometry (XL-MS), illuminate the dynamics of SARS-CoV-2 full-length nsp7 and nsp8 proteins and the nsp7:nsp8 protein complex. Results presented from the two techniques are complementary and validate the interaction surfaces identified from the published three-dimensional heterotetrameric crystal structure of the SARS-CoV-2 truncated nsp7:nsp8 complex. Furthermore, mapping of XL-MS data onto higher-order complexes suggests that SARS-CoV-2 nsp7 and nsp8 do not assemble into a hexadecameric structure as implied by the SARS-CoV full-length nsp7:nsp8 crystal structure. Instead, our results suggest that the nsp7:nsp8 heterotetramer can dissociate into a stable dimeric unit that might bind to nsp12 in the RTC without significantly altering nsp7-nsp8 interactions.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Proteomics/methods , Viral Nonstructural Proteins/chemistry , COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Humans , Hydrogen Deuterium Exchange-Mass Spectrometry , Models, Molecular , Protein Conformation , SARS-CoV-2/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
14.
J Genet ; 1002021.
Article in English | MEDLINE | ID: mdl-34187973

ABSTRACT

ADP ribosylation factor like protein 15 (ARL15) was identified as a novel susceptibility gene for rheumatoid arthritis (RA) based on a genomewide association study in a north Indian cohort. Mechanism of its action and functional relevance in RA biology remain largely unknown. In this study, we aimed to establish (i) ARL15 protein level in sera samples of RA patients; and (ii) its correlation, if any, with the RA associated ARL15 intronic single-nucleotide polymorphism (SNP) rs255758 (A>C). DNA, RNA and sera were isolated from blood samples of 117 RA patients and 25 age-matched healthy controls recruited at All India Institute of Medical Sciences, New Delhi with institutional ethical committee clearance. SNP rs255758 (A>C) was genotyped by Sanger sequencing; ARL15 RNA and protein levels were estimated by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively; and genotype-phenotype correlation established using Mann-Whitney nonparametric test. Very low level of ARL15 expression in human blood was confirmed at both RNA and protein levels. Genotype-wise distribution showed increased levels (P = 0.05) of ARL15 protein in RA patients with the homozygous variant (CC) as compared to AA + AC genotypes of rs255758. This first-ever correlation between higher ARL15 protein levels and the intronic susceptibility genotype (CC; rs255758) in RA patients may be of diagnostic and therapeutic relevance encouraging additional investigations.


Subject(s)
ADP-Ribosylation Factors/genetics , Arthritis, Rheumatoid/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Aged , Arthritis, Rheumatoid/epidemiology , Arthritis, Rheumatoid/pathology , Female , Gene Frequency , Genotype , Humans , India/epidemiology , Introns/genetics , Male , Middle Aged , Polymorphism, Single Nucleotide/genetics
15.
bioRxiv ; 2021 Mar 06.
Article in English | MEDLINE | ID: mdl-33688660

ABSTRACT

Coronavirus (CoV) non-structural proteins (nsps) assemble to form the replication-transcription complex (RTC) responsible for viral RNA synthesis. nsp7 and nsp8 are important cofactors of the RTC, as they interact and regulate the activity of RNA-dependent RNA polymerase (RdRp) and other nsps. To date, no structure of full-length SARS-CoV-2 nsp7:nsp8 complex has been published. Current understanding of this complex is based on structures from truncated constructs or with missing electron densities and complexes from related CoV species with which SARS-CoV-2 nsp7 and nsp8 share upwards of 90% sequence identity. Despite available structures being solved using crystallography and cryo-EM representing detailed snapshots of the nsp7:nsp8 complex, it is evident that the complex has a high degree of structural plasticity. However, relatively little is known about the conformational dynamics of the complex and how it assembles to interact with other nsps. Here, the solution-based structural proteomic techniques, hydrogen-deuterium exchange mass spectrometry (HDX-MS) and crosslinking mass spectrometry (XL-MS), illuminate the structural dynamics of the SARS-CoV-2 full-length nsp7:nsp8 complex. The results presented from the two techniques are complementary and validate the interaction surfaces identified from the published three-dimensional heterotetrameric crystal structure of SARS-CoV-2 truncated nsp7:nsp8 complex. Furthermore, mapping of XL-MS data onto higher order complexes suggests that SARS-CoV-2 nsp7 and nsp8 do not assemble into a hexadecameric structure as implied by the SARS-CoV full-length nsp7:nsp8 crystal structure. Instead our results suggest that the nsp7:nsp8 heterotetramer can dissociate into a stable dimeric unit that might bind to nsp12 in the RTC without altering nsp7-nsp8 interactions.

16.
Life Sci ; 259: 118377, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-32898526

ABSTRACT

The endothelium is the innermost vascular lining performing significant roles all over the human body while maintaining the blood pressure at physiological levels. Malfunction of endothelium is thus recognized as a biomarker linked with many vascular diseases including but not limited to atherosclerosis, hypertension and thrombosis. Alternatively, prevention of endothelial malfunctioning or regulating the functions of its associated physiological partners like endothelial nitric oxide synthase can prevent the associated vascular disorders which account for the highest death toll worldwide. While many anti-hypertensive drugs are available commercially, a comprehensive description of the key physiological roles of the endothelium and its regulation by endothelial nitric oxide synthase or vice versa is the need of the hour to understand its contribution in vascular homeostasis. This, in turn, will help in designing new therapeutics targeting endothelial nitric oxide synthase or its interacting partners present in the cellular pool. This review describes the central role of vascular endothelium in the regulation of endothelial nitric oxide synthase while outlining the emerging drug targets present in the vasculature with potential to treat vascular disorders including hypertension.


Subject(s)
Blood Pressure/physiology , Endothelium, Vascular/physiology , Heart/physiology , Nitric Oxide Synthase Type III/metabolism , Animals , Endothelium, Vascular/metabolism , Humans
17.
Expert Opin Investig Drugs ; 29(9): 1043-1057, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32658551

ABSTRACT

INTRODUCTION: Despite a large number of commercially available drugs, hypertension and related cardiovascular diseases remain a global problem. It is thus imperative that novel drugs and therapeutic strategies are regularly identified, and alternative targets explored. Dopamine ß hydroxylase (DBH), a key player in the catecholamine biosynthetic pathway, may provide a therapeutic opportunity and should be extensively explored as a target for potent anti-hypertensives. Inhibitors of DBH have been successful in combating hypertension, as evidenced by the outcome of clinical trials for etamicastat and zamicastat. AREAS COVERED: We shed light on the strategies employed to identify inhibitors of the enzyme and outline the advantages that the target might offer. Structural and functional details of the enzyme are described along with specific methodologies for drug discovery that were never utilized for the therapeutic target. EXPERT OPINION: Effective inhibitors of the enzyme may be identified with computer-aided structure-based design. Adoption of new methodologies and the assessment of newly designed inhibitors in DBH-specific animal models will provide new, safe, and cost-effective therapeutic opportunities.


Subject(s)
Antihypertensive Agents/pharmacology , Dopamine beta-Hydroxylase/antagonists & inhibitors , Hypertension/drug therapy , Animals , Benzopyrans/pharmacology , Dopamine beta-Hydroxylase/metabolism , Drug Design , Drug Discovery , Enzyme Inhibitors/pharmacology , Humans , Hypertension/enzymology , Hypertension/physiopathology , Imidazoles/pharmacology
18.
Int. j. high dilution res ; 19(3): 27-39, 2020.
Article in English | LILACS, HomeoIndex Homeopathy | ID: biblio-1146525

ABSTRACT

The prevalence of Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2) has undergone a historic transition from December 2019 to June 2020. Under the current circumstances, SARS-CoV-2 has become a key problem for the public health and economic steadiness of the global fraternity. Based on ample evidences from the global epidemiology of SARS-CoV-2 and MERS-CoV (Middle EastRespiratory Syndrome-Corona virus) scientists and physicians strappingly consider these viruses share structural and functional similarities of selected biologically active enzymes namely, 3CLpro, PLproand RdRp. Ultra-diluted homoeopathic medicine has the legacy to combat infectious as well as viral diseases since last two centuries. Thus, a systematic review on existing antiviral homoeopathic therapies was done in the current study and the need of appropriate clinical validation with proper in vitroas well as in vivostudies prior to make clinical endorsements in treating COVID-19 patients with homoeopathic medicines has been explained. A brief summary of the currently undergoing or recently completed homoeopathic treatments of COVID-19 has also been provided to attract many more similar homoeopathic treatment attempts to combat COVID-19.(AU)


Subject(s)
Coronavirus Infections/therapy , Statistics , Severe acute respiratory syndrome-related coronavirus , Homeopathy
19.
Toxicology ; 392: 22-31, 2017 12 01.
Article in English | MEDLINE | ID: mdl-28993186

ABSTRACT

Iron is implicated in age-related macular degeneration (AMD). The aim of this study was to see if long-term, experimental iron administration with aging modifies retinal and choroidal structures and expressions of iron handling proteins, to understand some aspects of iron homeostasis. Male Wistar rats were fed with ferrous sulphate heptahydrate (500mg/kg body weight/week, oral; elemental iron availability: 20%) from 2 months of age onward until they were 19.5 month-old. At 8, 14 and 20 months of age, they were sacrificed and serum and retinal iron levels were detected by HPLC. Oxidative stress was analyzed by TBARS method. The retinas were examined for cell death (TUNEL), histology (electron microscopy) and the expressions of transferrin, transferrin receptor-1 [TFR-1], H- and L-ferritin. In control animals, at any age, there was no difference in the serum and retinal iron levels, but the latter increased significantly in 14- and 20 month-old iron-fed rats, indicating that retinal iron accumulation proceeds with progression of aging (>14 months). The serum and retinal TBARS levels increased significantly with progression of aging in experimental but not in control rats. There was significant damage to choriocapillaris, accumulation of phagosomes in retinal pigment epithelium and increased incidence of TUNEL+ cells in outer nuclear layer and vacuolation in inner nuclear layer (INL) of 20 month-aged experimental rats, compared to those in age-matched controls. Vacuolations in INL could indicate a long-term effect of iron accumulation in the inner retina. These events paralleled the increased expression of ferritins and transferrin and a decrease in the expression of TFR-1 in iron-fed rats with aging, thereby maintaining iron homeostasis in the retina. As some of these changes mimic with those happening in eyes with AMD, this model can be utilized to understand iron-induced pathophysiological changes in AMD.


Subject(s)
Aging , Iron/administration & dosage , Retina/drug effects , Administration, Oral , Animals , Ferritins/genetics , Ferritins/metabolism , Ferrous Compounds/administration & dosage , In Situ Nick-End Labeling , Iron/blood , Macular Degeneration/physiopathology , Macular Degeneration/prevention & control , Male , Oxidative Stress/drug effects , Rats , Rats, Wistar , Receptors, Transferrin/genetics , Receptors, Transferrin/metabolism , Retina/pathology , Retinal Pigment Epithelium/drug effects , Retinal Pigment Epithelium/metabolism , Thiobarbituric Acid Reactive Substances/metabolism , Transferrin/genetics , Transferrin/metabolism
20.
Neurogenetics ; 18(3): 155-168, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28707163

ABSTRACT

Dopamine-ß-hydroxylase (DBH, EC 1.14.17.1), an oxido-reductase that catalyses the conversion of dopamine to norepinephrine, is largely expressed in sympathetic neurons and adrenal medulla. Several regulatory and structural variants in DBH associated with various neuropsychiatric, cardiovascular diseases and a few that may determine enzyme activity have also been identified. Due to paucity of studies on functional characterization of DBH variants, its structure-function relationship is poorly understood. The purpose of the study was to characterize five non-synonymous (ns) variants that were prioritized either based on previous association studies or Sorting Tolerant From Intolerant (SIFT) algorithm. The DBH ORF with wild type (WT) and site-directed mutagenized variants were transfected into HEK293 cells to generate transient and stable lines expressing these variant enzymes. Activity was determined by UPLC-PDA and corresponding quantity by MRMHR on a TripleTOF 5600 MS respectively of spent media from stable cell lines. Homospecific activity computed for the WT and variant proteins showed a marginal decrease in A318S, W544S and R549C variants. In transient cell lines, differential secretion was observed in the case of L317P, W544S and R549C. Secretory defect in L317P was confirmed by localization in ER. R549C exhibited both decreased homospecific activity and differential secretion. Of note, all the variants were seen to be destabilizing based on in silico folding analysis and molecular dynamics (MD) simulation, lending support to our experimental observations. These novel genotype-phenotype correlations in this gene of considerable pharmacological relevance have implications for dopamine-related disorders.


Subject(s)
Dopamine beta-Hydroxylase/genetics , Dopamine/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , Genetic Association Studies , HEK293 Cells , Humans , Structure-Activity Relationship
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