KNOWLEDGE ATTITUDE AND PRACTICE TOWARD COVID-19 DISEASE AMONG VARIOUS PROFESSIONALS: A CROSS-SECTIONAL ONLINE SURVEY

Objectives: This study aims to assess the knowledge, attitude, and practice associated with COVID-19 disease by undertaking a web-based online survey. Methods: A cross-sectional survey was conducted all over India during the initial phase of COVID-19 hit between March 19, 2020, and March 29, 2020. Anyone aged 18 years and above using social media were included in the study. The questionnaire had a section on sociodemography which had questions regarding age, gender, marital status, and occupation. This was followed by questions on knowledge, attitude, and practice regarding the COVID-19 pandemic. The knowledge scores were summarized as median with interquartile range as the data followed a non-normal distribution. Attitude and practice questions were summarized individually as proportions and its association with socio-demographic variables was established using Chi-square test. The statistical significance was set at p<0.05. Results: Occupational groups, marital status, and age group had significant difference between the groups with at least one of the practices with p<0.05. Conclusion: Since the study provides enhancing effect of knowledge toward protective behaviors, the awareness raising activities and health education through mass media and campaigns, this should urgently be conducted focusing on effectiveness of hand washing, cough etiquette, social distancing, and responsibility to inform suspected cases to local health authority to prevent COVID-19

TSH Receptor Gene and Autoimmune Thyroid Diseases

The primary regulators of thyroid activity are the thyroid-stimulating hormone (TSH) and its receptor (TSH-R). Studies have shown that genetic variants in the TSHR gene can increase susceptibility to autoimmune thyroid diseases (AITD). The TSHR gene is located on chromosome 14q31 and encodes a membrane-bound receptor that interacts with TSH to regulate thyroid hormone synthesis and secretion. AITD including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are the most common thyroid disorders, affecting millions of people worldwide. In AITD, autoantibodies can bind to and activate the TSHR, leading to increased thyroid hormone production and secretion in GD, or thyroid destruction and hypothyroidism in HT. In addition to its role in thyroid hormone synthesis and secretion, some studies also revealed that the TSHR has also been implicated in a variety of other physiological processes, including bone metabolism, reproduction, and immune regulation. Genetic variation in the TSHR region may affect the expression, post-translational processing, and/or protein structure, which in turn may cause or worsen the autoimmune response. The TSHR gene and its products are widely used in diagnostic testing for AITD. Understanding the molecular mechanisms underlying the interaction between the TSHR and autoantibodies is critical for developing new diagnostic and therapeutic strategies for AITD

Multifactorial Aspects Influencing Non-Alcoholic Fatty Liver Disease (Nafld)

Nonalcoholic fatty liver disease (NAFLD) is a growing public health concern, with a prevalence of up to 25% worldwide. While once considered a benign condition, NAFLD is now recognized as a major cause of chronic liver disease, liver failure, and hepatocellular carcinoma. The pathogenesis of NAFLD is multifactorial and involves a complex interplay between genetic, environmental, and metabolic factors. In this review, we provide an overview of the multifactorial aspects of NAFLD, including genetic predisposition, insulin resistance, dyslipidemia, gut microbiota, dietary factors, and physical inactivity. We also discuss the role of inflammation, oxidative stress, and hepatic steatosis in the progression of NAFLD to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma. Finally, we review the current and emerging therapies for NAFLD and NASH, including lifestyle modifications, pharmacological interventions, and surgical approaches. The multifactorial nature of NAFLD requires a comprehensive approach to diagnosis, treatment, and prevention, with a focus on addressing the underlying metabolic and environmental factors that contribute to its development and progression

Positive feedback and noise activate the stringent response regulator Rel in mycobacteria

Phenotypic heterogeneity in an isogenic, microbial population enables a subset of the population to persist under stress. In mycobacteria, stresses like nutrient and oxygen deprivation activate the stress response pathway involving the two-component system MprAB and the sigma factor, SigE. SigE in turn activates the expression of the stringent response regulator, rel. The enzyme polyphosphate kinase 1 (PPK1) regulates this pathway by synthesizing polyphosphate required for the activation of MprB. The precise manner in which only a subpopulation of bacterial cells develops persistence, remains unknown. Rel is required for mycobacterial persistence. Here we show that the distribution of rel expression levels in a growing population of mycobacteria is bimodal with two distinct peaks corresponding to low (L) and high (H) expression states, and further establish that a positive feedback loop involving the mprAB operon along with stochastic gene expression are responsible for the phenotypic heterogeneity. Combining single cell analysis by flow cytometry with theoretical modeling, we observe that during growth, noise-driven transitions take a subpopulation of cells from the L to the H state within a "window of opportunity" in time preceding the stationary phase. We find evidence of hysteresis in the expression of rel in response to changing concentrations of PPK1. Our results provide, for the first time, evidence that bistability and stochastic gene expression could be important for the development of "heterogeneity with an advantage" in mycobacteria.Comment: Accepted for publication in PLoS On

The Role of the Novel Exopolyphosphatase MT0516 in Mycobacterium tuberculosis Drug Tolerance and Persistence

Inorganic polyphosphate (poly P) has been postulated to play a regulatory role in the transition to bacterial persistence. In bacteria, poly P balance in the cell is maintained by the hydrolysis activity of the exopolyphosphatase PPX. However, the Mycobacterium tuberculosis PPX has not been characterized previously. Here we show that recombinant MT0516 hydrolyzes poly P, and an MT0516-deficient M. tuberculosis mutant exhibits elevated intracellular levels of poly P and increased expression of the genes mprB, sigE, and rel relative to the isogenic wild-type strain, indicating poly P-mediated signaling. Deficiency of MT0516 resulted in decelerated growth during logarithmic-phase in axenic cultures, and tolerance to the cell wall-active drug isoniazid. The MT0516-deficient mutant showed a significant survival defect in activated human macrophages and reduced persistence in the lungs of guinea pigs. We conclude that exopolyphosphatase is required for long-term survival of M. tuberculosis in necrotic lung lesions

Evaluating Gene Expression Dynamics Using Pairwise RNA FISH Data

Recently, a novel approach has been developed to study gene expression in single cells with high time resolution using RNA Fluorescent In Situ Hybridization (FISH). The technique allows individual mRNAs to be counted with high accuracy in wild-type cells, but requires cells to be fixed; thus, each cell provides only a “snapshot” of gene expression. Here we show how and when RNA FISH data on pairs of genes can be used to reconstruct real-time dynamics from a collection of such snapshots. Using maximum-likelihood parameter estimation on synthetically generated, noisy FISH data, we show that dynamical programs of gene expression, such as cycles (e.g., the cell cycle) or switches between discrete states, can be accurately reconstructed. In the limit that mRNAs are produced in short-lived bursts, binary thresholding of the FISH data provides a robust way of reconstructing dynamics. In this regime, prior knowledge of the type of dynamics – cycle versus switch – is generally required and additional constraints, e.g., from triplet FISH measurements, may also be needed to fully constrain all parameters. As a demonstration, we apply the thresholding method to RNA FISH data obtained from single, unsynchronized cells of Saccharomyces cerevisiae. Our results support the existence of metabolic cycles and provide an estimate of global gene-expression noise. The approach to FISH data presented here can be applied in general to reconstruct dynamics from snapshots of pairs of correlated quantities including, for example, protein concentrations obtained from immunofluorescence assays

Novel Role of Phosphorylation-Dependent Interaction between FtsZ and FipA in Mycobacterial Cell Division

The bacterial divisome is a multiprotein complex. Specific protein-protein interactions specify whether cell division occurs optimally, or whether division is arrested. Little is known about these protein-protein interactions and their regulation in mycobacteria. We have investigated the interrelationship between the products of the Mycobacterium tuberculosis gene cluster Rv0014c-Rv0019c, namely PknA (encoded by Rv0014c) and FtsZ-interacting protein A, FipA (encoded by Rv0019c) and the products of the division cell wall (dcw) cluster, namely FtsZ and FtsQ. M. smegmatis strains depleted in components of the two gene clusters have been complemented with orthologs of the respective genes of M. tuberculosis. Here we identify FipA as an interacting partner of FtsZ and FtsQ and establish that PknA-dependent phosphorylation of FipA on T77 and FtsZ on T343 is required for cell division under oxidative stress. A fipA knockout strain of M. smegmatis is less capable of withstanding oxidative stress than the wild type and showed elongation of cells due to a defect in septum formation. Localization of FtsQ, FtsZ and FipA at mid-cell was also compromised. Growth and survival defects under oxidative stress could be functionally complemented by fipA of M. tuberculosis but not its T77A mutant. Merodiploid strains of M. smegmatis expressing the FtsZ(T343A) showed inhibition of FtsZ-FipA interaction and Z ring formation under oxidative stress. Knockdown of FipA led to elongation of M. tuberculosis cells grown in macrophages and reduced intramacrophage growth. These data reveal a novel role of phosphorylation-dependent protein-protein interactions involving FipA, in the sustenance of mycobacterial cell division under oxidative stress

Bacterial Transmembrane Proteins that Lack N-Terminal Signal Sequences

Tail-anchored membrane proteins (TAMPs), a class of proteins characterized by their lack of N-terminal signal sequence and Sec-independent membrane targeting, play critical roles in apoptosis, vesicle trafficking and other vital processes in eukaryotic organisms. Until recently, this class of membrane proteins has been unknown in bacteria. Here we present the results of bioinformatic analysis revealing proteins that are superficially similar to eukaryotic TAMPs in the bacterium Streptomyces coelicolor. We demonstrate that at least four of these proteins are bona fide membrane-spanning proteins capable of targeting to the membrane in the absence of their N-terminus and the C-terminal membrane-spanning domain is sufficient for membrane targeting. Several of these proteins, including a serine/threonine kinase and the SecE component of the Sec translocon, are widely conserved in bacteria

Equation-Free Analysis of Two-Component System Signalling Model Reveals the Emergence of Co-Existing Phenotypes in the Absence of Multistationarity

Phenotypic differences of genetically identical cells under the same environmental conditions have been attributed to the inherent stochasticity of biochemical processes. Various mechanisms have been suggested, including the existence of alternative steady states in regulatory networks that are reached by means of stochastic fluctuations, long transient excursions from a stable state to an unstable excited state, and the switching on and off of a reaction network according to the availability of a constituent chemical species. Here we analyse a detailed stochastic kinetic model of two-component system signalling in bacteria, and show that alternative phenotypes emerge in the absence of these features. We perform a bifurcation analysis of deterministic reaction rate equations derived from the model, and find that they cannot reproduce the whole range of qualitative responses to external signals demonstrated by direct stochastic simulations. In particular, the mixed mode, where stochastic switching and a graded response are seen simultaneously, is absent. However, probabilistic and equation-free analyses of the stochastic model that calculate stationary states for the mean of an ensemble of stochastic trajectories reveal that slow transcription of either response regulator or histidine kinase leads to the coexistence of an approximate basal solution and a graded response that combine to produce the mixed mode, thus establishing its essential stochastic nature. The same techniques also show that stochasticity results in the observation of an all-or-none bistable response over a much wider range of external signals than would be expected on deterministic grounds. Thus we demonstrate the application of numerical equation-free methods to a detailed biochemical reaction network model, and show that it can provide new insight into the role of stochasticity in the emergence of phenotypic diversity