Biology subjects

Prasher, B.

Publications and source records attributed to Prasher, B..

8 recordsLinked to original sources

bioRxiv2024

Transcriptomic profiling of healthy individual-derived LCLs revealed inter-individual variability towards-hypoxia-responsive pathways

Hypoxia, or low oxygen levels, affects various developmental, physiological, and pathological processes. Its been consistently reported that there is an inter-individual variability at genetic and molecular pathways related to oxygen sensing and response. Understanding the underlying variability towards hypoxia sensing and response in health and disease conditions is challenging. The Prakriti stratification method of Ayurveda offers solutions, which classifies healthy individuals into different groups based on multisystem phenotyping. Our lab has previously used this method and provided evidence for the variability in hypoxia responsiveness physiologically among healthy individuals at population levels. Our current study seeks to understand hypoxia sensing and response pathways at cellular levels. We used eight Lymphoblastoid cell lines (LCLs) developed from healthy individuals of extreme Prakriti types. Hypoxia challenge experiments were performed using 0.2% oxygen for 24 and 48 hrs. of chronic hypoxia and captured global transcriptomics profiles. Differentially expressed genes revealed activation of core hypoxia-induced transcriptomic signatures, such as HIF-1 signaling and their metabolic reprogramming in pooled as well as in all Prakriti groups. However, there were Prakriti-specific differences, such as activation of TGF-{beta} mediated ROS and PI3K/AKT/mTOR driven mTORC1 complex in Kapha, downregulation of cholesterol homeostasis and regulation of Phosphoinositide biosynthesis in membrane potential observed in the Pitta group. In contrast, ER stress-induced activation of cell survival response via Unfolded protein response in the Vata group. The Prakriti stratification method will provide a novel method to understand inter-individual differences in hypoxia response pathways. SignificanceHypoxia can significantly impact various aspects of our health and well-being. All nucleated cells sense and respond to hypoxia, depending upon their cellular and metabolic activities. Its wide utility and spatiotemporal regulation make it a crucial target to study. We have used the Prakriti stratification method of Ayurveda to explore hypoxia sensing and response at cellular levels. Lymphoblastoid Cell Lines (LCLs) developed from the peripheral blood of stratified healthy individuals have been utilized to study the expression level variability at the baseline and hypoxia-induced conditions. The outcomes of our study will be crucial to understanding inter-individual variability in response to hypoxia overlayed baseline variations. Resulting in differential susceptibility towards hypoxic response in health and contributes to understanding variable outcomes in disease conditions. Molecular targets from our study will further be utilized for interventional drug targets in hypoxia-induced disease conditions.

cell biology↗

bioRxiv2024

KAT3 mutations impair neural crest migration through EMT regulators snai1b and snai2 in Rubinstein Taybi Syndrome

Rubinstein Taybi syndrome, a rare congenital disease is caused by mutation in KAT3 genes, EP300 and CREBBP. A subset of tissues affected in RSTS have their origin in neural crest cells, prompting our exploration into the role of KAT3 in neural crest development. Our zebrafish RSTS models generated by knocking down or mutating ep300a and cbpa genes, reveal defects in neural crest migration and its derived tissues when KAT3 genes are perturbed. We also demonstrate that the effects on neural crest can be reversed by HDAC inhibition in in morphant embryos. KAT3 knockdown causes downregulation of EMT regulators, snai1b and snai2. Snai2 is known to repress cdh6b in neural crest cells facilitating their delamination from neural tube and migration. We generated RSTS patient-derived iPSC line and differentiated them into neural crest cells in vitro. We show that role of KAT3 proteins in neural crest migration is conserved in human iPSC derived neural crest cells. Our findings make a case for classifying RSTS as a neurocristopathy. HighlightsO_LIPerturbation of KAT3 gene expression in zebrafish recapitulates the Rubinstein Taybi patient defects C_LIO_LIThe zebrafish model of Rubinstein Taybi model reveals defects in neural crest cell migration C_LIO_LIKAT3 proteins regulate snai2, snai1b and cdh6, genes important for neural crest migration C_LIO_LIThe neural crest migration defects in the zebrafish model can be partially rescued by modulating the global acetylation levels C_LIO_LIStudy of RSTS patient-derived neural crest cells reveals that the role of KAT3 in neural crest migration is conserved across vertebrates C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/593474v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1761fceorg.highwire.dtl.DTLVardef@220e21org.highwire.dtl.DTLVardef@1cdd311org.highwire.dtl.DTLVardef@1dc0e53_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2022

Population History and Genome Wide Association Studies of Birth Weight in a Native High Altitude Ladakhi Population

Pathological low birth weight due to fetal growth restriction (FGR)is an important predictor of adverse obstetric and neonatal outcomes. It is more common amongst native lowlanders when gestating in the hypoxic environment of high altitude, whilst populations who have resided at high altitude for many generations are relatively protected. Genetic study of pregnant populations at high altitude permits exploration of the role of hypoxic in FGR pathogenesis, and perhaps of FGR pathogenesis more broadly. We studied the umbilical cord blood DNA of 316 neonates born to pregnant women managed at the Sonam Norboo Memorial Hospital, Ladakh (altitude 3540m) between February 2017-January 2019. Principal component, admixture and genome wide association studies (GWAS) were applied to dense single nucleotide polymorphism (SNP) genetic data, to explore ancestry and genetic predictors of low birth weight. Our findings support Tibetan ancestry in the Ladakhi population, with subsequent admixture with neighboring Indo-Aryan populations. Fetal growth protection was evident in Ladakhi neonates. Although no variants achieved genome wide significance, we observed nominal association of seven variants across genes (ZBTB38, ZFP36L2, HMGA2, CDKAL1, PLCG1) previously associated with birthweight.

genetics↗

bioRxiv2021

Anti-SARS-CoV-2 potential of Cissampelos pareira L. identified by Connectivity map-based analysis and in vitro studies

BackgroundViral infections have a history of abrupt and severe eruptions through the years in the form of pandemics. And yet, definitive therapies or preventive measures are not present. PurposeHerbal medicines have been a source of various antiviral compounds. An accelerated repurposing potential of antiviral herbs can provide usable drugs and identify druggable targets. In this study, we dissect the anti-coronavirus activity of Cissampelos pareira L (Cipa). using an integrative approach. MethodsWe analysed the signature similarities between predicted antiviral agents and Cipa using the connectivity map (https://clue.io/). Next, we tested the anti-SARS-COV-2 activity of Cipa in vitro. A three-way comparative analysis of Cipa transcriptome, COVID-19 BALF transcriptome and CMAP signatures of small compounds was also performed. ResultsSeveral predicted antivirals showed a high positive connectivity score with Cipa such as apcidin, emetine, homoharringtonine etc. We also observed 98% inhibition of SARS-COV-2 replication in infected Vero cell cultures with the whole extract. Some of its prominent pure constituents e.g pareirarine, cissamine, magnoflorine exhibited 40-80% inhibition. Comparison of genes between BALF and Cipa showed an enrichment of biological processes like transcription regulation and response to lipids, to be downregulated in Cipa while being upregulated in COVID-19. CMAP also showed that Triciribine, torin-1 and VU-0365114-2 had positive connectivity with BALF 1 and 2, and negative connectivity with Cipa.

systems biology↗

bioRxiv2021

Traditional use of Cissampelos pareira L. for hormone disorder and fever provides molecular links of ESR1 modulation to viral inhibition

Bioactive fractions or compounds obtained from medicinal plants have been used for the treatment of multiple diseases. This effect could be due to common pathways underlying these conditions that are targeted by such medicines. In this study, we explored the molecular basis of action of one such herbal formulation Cissampelos pareira, used for the treatment of female hormone disorders and fever. Genome-wide expression studies on MCF7 cell lines treated with Cipa extract were carried out using Affymetrix arrays. Transcriptome analysis revealed a downregulation of signatures of estrogen response governed by estrogen receptor (ER). Molecular docking analysis identified 38 constituent molecules in Cipa that potentially bind ({Delta}G< -7.5) with ER at the same site as estrogen. Cipa transcriptome signatures show high positive connectivity (https://clue.io/) scores with protein translation inhibitors such as emetine (score: 99.61) and knockdown signatures of genes linked to the antiviral response such as ribosomal protein RPL7 (score: 99.92), which is also an ER coactivator. Cipa exhibits antiviral activity in dengue infected MCF7 cells that is decreased upon ESR1 (estrogen receptor 1) gene knockdown. This approach reveals a novel pathway involving ESR1-RPL7 axis that could be a potential target in dengue viral infection.

genomics↗

bioRxiv2021

Baseline cell proliferation rates and response to UV differ in Lymphoblastoid Cell Lines derived from healthy individuals of extreme constitution types

Differences in human phenotypes and susceptibility to complex diseases are an outcome of genetic and environmental interactions. This is evident in diseases that progress through a common set of intermediate patho-endophenotypes. Precision medicine aims to delineate the molecular players for individualized and early interventions. Functional studies in Lymphoblastoid Cell Line (LCL) model of phenotypically well characterized healthy individuals can help deconvolute and validate these molecular mechanisms. We developed LCLs from eight healthy individuals belonging to three extreme constitution types, deep phenotyped on the basis of Ayurveda. LCLs were characterized by karyotyping and immunophenotyping. Growth characteristics and response to UV was studied in these LCLs. We observed significant differences in cell proliferation rates between the contrasting groups such that one type (Kapha) proliferates significantly slower than the other two (Vata, Pitta). In response to UV, one fast growing group (Vata) shows higher cell death but recovers its numbers due to inherent higher rates of proliferation. The baseline differences in cell proliferation are key to understanding the survival of cells in UV stress. Variability in baseline cellular phenotypes not only explains the cellular basis of different constitutions types but can also help set priors during designing an individualized therapy with DNA damaging agents. This is the first study of its kind that shows variability of intermediate patho-phenotypes amongst healthy individuals that have implications in precision medicine.

cell biology↗

bioRxiv2020

Genetic differences between extreme and composite constitution types from whole exome sequences reveal actionable variations

Personalized medicine relies on successful identification of genome-wide variations that governs inter-individual differences in phenotypes and system level outcomes. In Ayurveda, assessment of composite constitution types "Prakriti" forms the basis for risk stratification, predicting health and disease trajectories and personalized recommendations. Here, we report a novel method for identifying pleiotropic genes and variants that associate with healthy individuals of three extreme and contrasting "Prakriti" constitutions through exome sequencing and state-of-the-art computational methods. Exome Seq of three extreme Prakriti types from 108 healthy individuals 54 each from genetically homogeneous populations of North India (NI, Discovery cohort) and Western India (VADU, Replication cohort) were evaluated. Fishers Exact Test was applied between Prakriti types in both cohorts and further permutation based p-value was used for selection of exonic variants. To investigate the effect of sample size per genetic association test, we performed power analysis. Functional impact of differentiating genes and variations were inferred using diverse resources -Toppfun, GTEx, GWAS, PheWAS, UK Biobank and mouse knockdown/knockout phenotype (MGI). We also applied supervised machine learning approach to evaluate the association of exonic variants with multisystem phenotypes of Prakriti. Our targeted investigation into exome sequencing from NI (discovery) and VADU (validation) cohorts datasets provide ~7,000 differentiating SNPs. Closer inspection further identified a subset of SNPs (2407 (NI) and 2393 (VADU)), that mapped to an overlapping set of 1181 genes. This set can robustly stratify the Prakriti groups into three distinct clusters with distinct gene ontological (GO) enrichments. Functional analysis further strengthens the potential pleiotropic effects of these differentiating genes/variants and multisystem phenotypic consequences. Replicated SNPs map to some very prominent genes like FIG4, EDNRA, ANKLE1, BCKDHA, ATP5SL, EXOCS5, IFIT5, ZNF502, PNPLA3 and IL6R. Lastly, multivariate analysis using random forest uncovered rs7244213 within urea transporter SLC14A2, that associate with an ensemble of features linked to distinct constitutions. Our results reinforce the concept of integration of Prakriti based deep phenotypes for risk stratification of healthy individuals and provides markers for early actionable interventions.

genomics↗

bioRxiv2020

Adhatoda Vasica ameliorates cellular hypoxia dependent mitochondrial dysfunction in acute and severe asthmatic mice.

Severe asthma is a chronic airway disease that exhibits poor response to conventional asthma therapies. Growing evidence suggests that elevated hypoxia increases the severity of asthmatic inflammation among patients and in model systems. In this study, we elucidate the therapeutic effects and mechanistic basis of Adhatoda Vasica (AV) aqueous extract on mouse models of acute allergic as well as severe asthma subtypes at physiological, histopathological, and molecular levels. Oral administration of AV extract attenuates the increased airway resistance and inflammation in acute allergic asthmatic mice and alleviates the molecular signatures of steroid (dexamethasone) resistance like IL-17A, KC, and HIF-1 (hypoxia inducible factor-1alpha) in severe asthmatic mice. AV inhibits HIF-1 levels through restoration of expression of its negative regulator-PHD2 (prolyl hydroxylase domain-2). Alleviation of hypoxic response mediated by AV is further confirmed in the acute and severe asthma model. AV reverses cellular hypoxia-induced mitochondrial dysfunction in human bronchial epithelial cells - evident from bioenergetic profiles and morphological analysis of mitochondria. In silico docking of AV constituents reveal higher negative binding affinity for C and O-glycosides for HIF-1, IL-6, Janus kinase 1/3, TNF- and TGF-{beta}-key players of hypoxia-inflammation. This study for the first time provides a molecular basis of action and effect of AV whole extract that is widely used in Ayurveda practice for diverse respiratory ailments. Further, through its effect on hypoxia-induced mitochondrial dysfunction, the study highlights its potential to treat severe steroid-resistant asthma. Significance StatementSevere asthma is a global health concern with a large fraction unresponsive to current treatment modalities involving corticosteroids. Recent findings suggest that elevated hypoxia has a critical role in severity of asthma. Here, we report therapeutic treatment with aqueous extract of Adhatoda Vasica (AV), an ayurvedic medicine, attenuates sever steroid insensitive asthmatic features in mice. The observed effects of AV are through inhibition of hypoxic response, both in vivo and in vitro. AV also reverses mitochondrial dysfunction, a key consequence associated with hypoxia, and asthma. This study highlights the translational potential of AV for the treatment of severe asthma and provides opportunities for its usage in other disease conditions where hypoxia is pertinent.

immunology↗