Biology subjects

Gupta, S.

Publications and source records attributed to Gupta, S..

At least 235 records · Page 13Linked to original sources

bioRxiv2022

Common risk variants in AHI1 are associated with childhood steroid-sensitive nephrotic syndrome

BackgroundSteroid-sensitive nephrotic syndrome (SSNS) is the most common form of kidney disease in children worldwide. Genome-wide association studies (GWAS) have demonstrated association of SSNS with genetic variation at HLA-DQ/DR and have identified several non-HLA loci that aid in further understanding of disease pathophysiology. We sought to identify additional genetic loci associated with SSNS in children of Sri Lankan and European ancestry. MethodsWe conducted a GWAS in a cohort of Sri Lankan individuals comprising 420 pediatric patients with SSNS and 2339 genetic ancestry matched controls obtained from the UK Biobank. We then performed a trans-ethnic meta-analysis with a previously reported European cohort of 422 pediatric patients and 5642 controls. ResultsOur GWAS confirmed the previously reported association of SSNS with HLA-DR/DQ (rs9271602, p=1.12x10-27, odds ratio[OR]=2.75). Trans-ethnic meta-analysis replicated these findings and identified a novel association at AHI1 (rs2746432, p=2.79x10-8, OR=1.37), which was also replicated in an independent South Asian cohort. AHI1 is implicated in ciliary protein transport and immune dysregulation, with rare variation in this gene contributing to Joubert syndrome type 3. ConclusionsCommon variation in AHI1 confers risk of the development of SSNS in both Sri Lankan and European populations. The association with common variation in AHI1 further supports the role of immune dysregulation in the pathogenesis of SSNS and demonstrates that variation across the allele frequency spectrum in a gene can contribute to disparate monogenic and polygenic diseases. AUTHOR SUMMARYSteroid-sensitive nephrotic syndrome (SSNS) is the most common kidney disease in children worldwide, but the cause of disease is not well understood. Genome-wide association studies (GWAS) in SSNS have shown that genes in the classical HLA region (the human immune centre) and several genes outside of this region are associated with the disease, which has allowed us to further understand the cause of disease. We performed a GWAS of Sri Lankan ancestry that included 420 paediatric patients and 2339 ancestry-matched controls and confirmed association at HLA-DQ/DR with SSNS. We then performed a Sri Lankan-European trans-ethnic meta-analysis and identified a new association with SSNS outside of HLA, in AHI1. This finding further supports the role of immune system involvement in the etiology of SSNS and increases our knowledge of the genetic causes of disease. AHI1 is a gene that can also cause ciliary problems and demonstrates that different genetic variants within the same gene can contribute to both single-gene (Joubert syndrome, a rare disease that causes kidney and neurological problems) and multi-gene diseases (SSNS).

genetics↗

bioRxiv2022

Plasticity and interactions in the odor responses of maxillary palps neurons in Aedes aegypti

Maxillary palps, in addition to the antennae, are major olfactory organs in mosquitoes and play an important role in the detection of human hosts. The sensory neurons of the maxillary palps reside in the capitate peg sensilla, each of which contains three neurons. In Aedes aegypti, the neuron with the largest spike amplitude in the sensillum is known to detect carbon dioxide. However, the responses of the other two neurons and the functional consequences of the grouping of these neurons within sensilla are not well understood. Here we identify odorants that activate the other two neurons. We detect a short-term plasticity in the odor-evoked local field potential of the sensillum and show that it originates in the spiking responses of the smallest-amplitude neuron, even though all three neurons contribute to the local field potential. We also detect inhibitory interactions among these neurons within the sensillum. We further show that the plasticity and the lateral interactions are functionally important as they affect the responses of the downstream projection neurons in the antennal lobe.

neuroscience↗

bioRxiv2022

Tip-links serve as force-pass filter to fulfil the role of gating-springs

Tip-links as gating-spring in the mechanotransduction in hearing is still a debate. While the molecular elasticity of individual tip-link proteins warrants its candidature, the apparent rigidity from the heterotetrameric tip-links assembly refutes the claim. Using force-clamp experiments and simulations, we report that the heterotetrameric assembly is the natural selection for the gating-springs. Tip-links follow slip-ideal-slip bonds with increasing force. While in slip, the complex dissociates monotonously, ideal-bond interface responds indifferently to various auditory inputs. Insensitivity to forces renders tip-links as low-force pass filter, characteristic of gating-spring. Individual tip-links, however, forms slip-catch-slip bonds under tension. While catch bonds turn stronger with force from loud sound, our Langevin dynamics indicated the transition from slip-catch to slip-ideal bonds as cooperative effect of the dimers of individual protein complexes in tip-links. From molecular dynamics, we deciphered the molecular mechanism of catch bonds and its importance in deafness.

biophysics↗

bioRxiv2022

Sentences, Words, Attention: A "Transforming" Aphorism of miRNA Discovery

Discovering pre-miRNAs is the core of miRNA discovery. Using traditional sequence/structural features many tools have been published to discover miRNAs. However, in practical applications like genomic annotations, their actual performance has been far away from acceptable. This becomes more grave in plants where unlike animals pre-miRNAs are much more complex and difficult to identify. This is reflected by the huge gap between the available software for miRNA discovery and species specific miRNAs information for animals and plants. Here, we present miWords, an attention based genomic language processing transformer and context scoring deep-learning approach, with an optional sRNA-seq guided CNN module to accurately identify pre-miRNA regions in plant genomes. During a comprehensive bench-marking the transformer part of miWords alone significantly outperformed the compared published tools with consistent performance while breaching accuracy of 98% across a large number of experimentally validated data. Performance of miWords was also evaluated across Arabidopsis genome where also miWords, even without using its sRNA-seq reads module, outperformed those software which essentially require sRNA-seq reads to identify miRNAs. miWords was run across the Tea genome, reporting 803 pre-miRNA regions, all validated by sRNA-seq reads from multiple samples, and 10 randomly selected cases re-validated by qRT-PCR.

bioinformatics↗

bioRxiv2022

Involuntary breathing movement pattern recognition and classification via force based sensors.

The study presents a novel scheme that recognizes and classifies different sub-phases within the involuntary breathing movement (IBM) phase during breath-holding (BH). We collected force data from eight recreational divers until the conventional breakpoint (CB). They were in a supine position on force plates. We segmented their data into the no-movement (NM) phase aka easy phase and IBM phase (comprising several events or sub-phases of IBM). The acceleration and jerk were estimated from the data to quantify the IBMs, and phase portraits were developed to select and extract specific features. The K means clustering was performed on these features to recognize different sub-phases within the IBM phase. We found five-six optimal clusters separating different sub-phases within the IBM phase. These clusters separating different sub-phases have physiological relevance to internal struggle and were labeled as classes for classification using support vector machine (SVM), naive bayes (NB), decision tree (DT), and K-nearest neighbor (K-NN). In comparison with no feature selection and extraction, we found that our phase portrait method of feature selection and extraction had a low computational cost and high robustness of 96-99% accuracy.

bioengineering↗

bioRxiv2022

Signal Alignment Enables Analysis of DIA Proteomics Data from Multisite Experiments

DIA has become a mainstream method for quantitative proteomics, however consistent quantification across multiple LC-MS/MS instruments remains a bottleneck in parallelizing the data-acquisition. To produce a highly consistent and quantitatively accurate data matrix, we have developed DIAlignR which uses raw fragment-ion chromatograms for cross-run alignment. Its performance on a gold standard annotated dataset, demonstrates a threefold reduction in the identification error-rate when compared to standard non-aligned DIA results. A similar performance is achieved for a dataset of 229 runs acquired using 11 different LC-MS/MS setups. Finally, the analysis of 949 plasma runs with DIAlignR increased the number of statistically significant proteins by 43% and 62% for insulin resistant (IR) and respiratory viral infection (RVI), respectively compared to prior analysis without it. Hence, DIAlignR fills a gap in analyzing DIA runs acquired in-parallel using different LC-MS/MS instrumentation.

bioinformatics↗

bioRxiv2022

Biological evaluation of novel side chain containing CQTrICh-analogs as antimalarials and their development as PfCDPK1 kinase inhibitors

To combat the emergence of drug resistance against the existing antimalarials, novel side chain containing 7-chloroquinoline-indole-chalcones tethered with a triazole (CQTrICh-analogs 7 (a-s) and 9) were designed and synthesized by reacting substituted 1-phenyl-3-(1-(prop-2-yn-1- yl)-1H-indol-3-yl) prop-2-en-1-one and 1-(prop-2-yn-1-yl)-1H-indole-3-carbaldehyde with 4- azido-7-chloroquinoline, respectively via a click reaction. The selected CQTrICh-analogs: 7l and 7r inhibited chloroquine-sensitive (3D7) and resistant (RKL-9) strains of Plasmodium falciparum, with IC50 values of 2.4 {micro}M & 1.8 {micro}M (7l), and 3.5 {micro}M & 2.7 {micro}M (7r), respectively, and showed insignificant hemolysis and cytotoxicity in mammalian cells. Intra-erythrocytic progression studies revealed that the active hybrids: 7l and 7r are effective against the mature stages of the parasite. Given the importance of Calcium-Dependent Protein Kinase 1 (PfCDPK1) in the parasite biology, notably during late schizogony and subsequent invasion of merozoites into host RBCs, we identified this protein as a possible molecular target of these active hybrids. In silico interaction analysis indicated that 7l and 7r stably interact with the catalytically active ATP-binding pocket of PfCDPK1, by the formation of energetically favorable H-bonds. Furthermore, in vitro Microscale Thermophoresis and kinase assays with recombinant PfCDPK1 demonstrated that the active hybrids interact with and inhibit the kinase activity, thus presumably responsible for the parasite growth inhibition. Interestingly, 7l and 7r showed no inhibitory effect on the human kinases, indicating that they are selective for the parasite kinase. Conceivably, we report the antiplasmodial potential of novel kinase targeting bio-conjugates, a step towards developing pan-kinase inhibitors, which is a prerequisite for cross-stage anti-malarial protection. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/498981v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@113574borg.highwire.dtl.DTLVardef@c81a33org.highwire.dtl.DTLVardef@1301d22org.highwire.dtl.DTLVardef@1c8cac5_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2022

Polymorphisms Predicting Phylogeny in Hepatitis B Virus (HBV)

Hepatitis B viruses (HBV) are compact viruses with circular genomes of [~]3.2kb in length. Four genes (HBx, Core, Surface and Polymerase) generating seven products are encoded on overlapping reading frames. Ten HBV genotypes have been characterised (A-J), which may account for differences in transmission, outcomes of infection, and treatment response. However, HBV genotyping is rarely undertaken, and sequencing remains inaccessible in many settings. We used a machine learning approach based on random forest algorithms (RFA) to assess which amino acid (aa) sites in the genome are most informative for determining genotype. We downloaded 5496 genome-length HBV sequences from a public database, excluding recombinant sequences, regions with conserved indels, and genotypes I/J. Each gene was separately translated into aa, and the proteins concatenated into a single sequence (length 1614aa). Using RFA, we searched for aa sites predictive of genotype, and assessed co-variation among the sites with a Mutual Information (MI)-based method. We were able to discriminate confidently between genotypes A-H using 10 aa sites. 5/10 sites were identified in Polymerase (Pol), of which 4/5 were in the spacer domain, and a single site in reverse transcriptase. A further 4/10 sites were located in Surface protein, and a single site in HBx. There were no informative sites in Core. Properties of the aa were generally not conserved between genotypes at informative sites. Co-variation analysis identified 55 pairs of highly-linked sites. Three RFA-identified sites were represented across all pairs (two sites in spacer, and one in HBx). Residues that co-vary with these sites are concentrated in the small HBV surface gene. We also observe a cluster of sites adjacent to the Surface promoter region that co-vary with a spacer residue. Overall, we have shown that RFA analysis is a powerful tool for identifying aa sites that predict HBV lineage, with an unexpectedly high number of such sites in the spacer domain, which has conventionally been viewed as unimportant for structure or function. Our results improve ease of genotype prediction from limited regions of HBV sequence, and may have implications for understanding HBV evolution and the role of the spacer domain.

genomics↗

bioRxiv2022

Graphene Biointerface for Cardiac Arrhythmia Diagnosis and Treatment

Heart rhythm disorders, known as arrhythmias, cause significant morbidity and are one of the leading causes of mortality. Cardiac arrhythmias are primarily treated by implantable devices, such as pacemakers and defibrillators, or by ablation therapy guided by electroanatomical mapping. Pharmacological treatments are mostly ineffective. Both implantable and ablation therapies require sophisticated biointerfaces for electrophysiological measurements of electrograms and delivery of therapeutic stimulation or ablation energy. In this work, we report for the first time on graphene biointerface for in vivo cardiac electrophysiology. Leveraging sub-micrometer thick tissue-conformable graphene arrays, we demonstrate sensing and stimulation of the open mammalian heart both in vitro and in vivo. Furthermore, we demonstrate graphene pacemaker treatment of a pharmacologically-induced arrhythmia, AV block. The arrays show effective electrochemical properties, namely interface impedance down to 40 Ohmxcm2 at 1kHz, charge storage capacity up to 63.7 mC/cm2, and charge injection capacity up to 704 C/cm2. Transparency of the graphene structures allows for simultaneous optical mapping of cardiac action potentials and optogenetic stimulation while performing electrical measurements and stimulation. Our report presents evidence of the significant potential of graphene biointerfaces for the future clinical device- and catheter-based cardiac arrhythmias therapies.

bioengineering↗

bioRxiv2022

Preclinical efficacy of bacosides-lauric acid nano-herbal formulation incomparison to rivastigmine for treatment of Alzheimer's disease

Despite decades of rigorous scientific endeavors for Alzheimers disease (AD) drug development, massive failures in clinical trials is continuously posing healthcare and societal burden. Currently recommended single targeted drugs including rivastigmine with limited bioavailability can alleviate AD symptoms only for a limited period of time but unable to reverse the disease progression. Recent evidences consider poly-pharmacological and multi-targeted agents aiming at amyloid and tau burden, neuroinflammation, neuroprotection and cognitive enhancement as potential treatment options. In this regard, bioactive herbal compounds with holistic action and minimal adversities have gained prominence, though lacunae in their scientific validation and limited bio-permeability to cross BBB represent major hurdles. Previously, we showed that lactoferrin conjugated PEG-S-S-PLA-PCL-OH efficaciously delivered herbal compounds to brain and such nano-herbal formulation of bacosides-lauric acid (BAN-LAN) attenuated neuronal damages induced by scopolamine in vitro. Here, we tested the preclinical potential of BAN-LAN in reversal of AD pathologies in 5XFAD transgenic mice. Our nano-herbal formulation substantially reduced amyloid burden by clearing A{beta} plaques in the hippocampus of 5XFAD mice and also attenuated a{beta}42 induced alterations in AD associated gene expression in hippocampal neurons in vitro. It showed neuroprotection by rescuing neuronal damage and promoting neurogenesis in the hippocampus of AD transgenic mice. Anti-neuroinflammatory properties were also exhibited by the formulation as evident from inhibition of hippocampal astrocytic and microglial activation in 5XFAD mice. BAN-LAN showed cognitive efficacy by restoring memory impairment in AD transgenic mice and effects were more pronounced than unconjugated natural form and rivastigmine. These findings suggest that BAN-LAN may serve as a promising therapeutic agent for AD with better brain penetration and targeting multiple AD pathways.

pharmacology and toxicology↗

bioRxiv2022

Combinatorial encoding of odors in the mosquito antennal lobe

Among the cues that a mosquito uses to find a host for blood-feeding, the smell of the host plays an important role. Previous studies have shown that host odors contain hundreds of chemical odorants, which are detected by different receptors on the peripheral sensory organs of mosquitoes. But how individual odorants are encoded by downstream neurons in the mosquito brain is not known. We developed an in vivo preparation for patch-clamp electrophysiology to record from projection neurons and local neurons in the antennal lobe of Aedes aegypti. Combining intracellular recordings with dye-fills, morphological reconstructions, and immunohistochemistry, we identify different sub-classes of antennal lobe neurons and their putative interactions. Our recordings show that an odorant can activate multiple neurons innervating different glomeruli, and that the stimulus identity and its behavioral preference are represented in the population activity of the projection neurons. Our results provide the first detailed description of olfactory neurons in the central nervous system of mosquitoes and lay a foundation for understanding the neural basis of their olfactory behaviors.

neuroscience↗

bioRxiv2022

Birth and Death in Terminal Complement Pathway

The cytolytic activity of the membrane attack complex (MAC) has a crucial role in the complement-mediated elimination of pathogens. Terminal complement pathway (TCP) genes encode the proteins that form the MAC. Although the TCP genes are well conserved within most vertebrate species, the early evolution of the TCP genes is poorly understood. Based on the comparative genomic analysis of the early evolutionary history of the TCP homologs, we evaluated four possible scenarios that could have given rise to the vertebrate TCP. Currently available genomic data support a scheme of complex sequential protein domain gains that may be responsible for the birth of the vertebrate C6 gene. The subsequent duplication and divergence of this vertebrate C6 gene formed the C7, C8, C8{beta}, and C9 genes. Compared to the widespread conservation of TCP components within vertebrates, we discovered that C9 has disintegrated in the genomes of galliform birds. Publicly available genome and transcriptome sequencing datasets of chicken from Illumina short read, PacBio long read, and Optical mapping technologies support the validity of the genome assembly at the C9 locus. In this study, we have generated a >120X coverage whole-genome Chromium 10x linked-read sequencing dataset for the chicken and used it to verify the loss of the C9 gene in the chicken. We find multiple CR1 (chicken repeat 1) element insertions within and near the remnant exons of C9 in several galliform bird genomes. The reconstructed chronology of events shows that the CR1 insertions occurred after C9 gene loss in an early galliform ancestor. Our study of C6 gene birth in an early vertebrate ancestor and C9 gene death in galliform birds provides insights into the evolution of the TCP.

immunology↗

bioRxiv2022

N-terminal helices and A domain of archaeal FtsY facilitate SRP54 binding and the association with cell membrane

The process of protein translocation is essential to the maintenance of cellular life and has been critically addressed in eukaryotes and bacteria. However, little information is available regarding protein translocation across archaeal membranes. The signal recognition particle (SRP) plays an important role in this process. It binds the signal peptide at the N-terminus of the polypeptide chain and interacts with the cognate SRP receptor (FtsY) located on the target membrane to form a targeting complex (TC). Concomitant GTP hydrolysis by SRP and FtsY delivers the polypeptide to the adjacent protein-conducting channel. The present study aims to characterize the structural domains of FtsY contributing to the targeting complex (TC) formation in Sulfolobus acidocaldarius, a thermo-acidophilic crenarchaeon. The contacting residues between SRP54 and FtsY were mapped along the N1-N3 helices. Interestingly, the previously reported crystal structure did not take the N-terminal A domain into account - a region rich in negatively charged residues. Such observation led us to investigate the contribution of each of the three participating helices (N1-3) in terms of membrane association and functional TC formation. Through biophysical analyses of SRP-FtsY and FtsY-membrane interaction, and biochemical characterization of the reciprocal GTPase activity, this work sought to elucidate the minimal structural motif controlling the archaeal TC assembly.

biochemistry↗

bioRxiv2022

Informational Masking Can Constrain Acoustically Guided Mating Behavior

Animals often communicate acoustically in noisy social environments, yet how receivers extract relevant information from overlapping sounds is poorly understood. Studies of animal communication in noise are typically based on a traditional filterbank model of hearing focused on energetic masking, where spectrotemporal overlap in peripheral auditory filters limits signal audibility. By contrast, studies of human speech show that background sounds can also interfere with selecting and attending to otherwise audible signals in a phenomenon known as informational masking. Whether informational masking constrains acoustic communication in nonhuman animals remains poorly understood. Through controlled laboratory experiments with treefrogs (Hyla chrysoscelis), we demonstrate, for the first time in a nonhuman animal, that informational masking can impair crucial mate-choice decisions when vocal signals and other concurrent sounds share similar temporal features. These impacts spanned a wide range of signal-to-noise ratios, occurred in the absence of spectrotemporal overlap in the auditory periphery, and were strongest when interfering sounds fell within a frequency band salient for vocal processing. Our findings challenge conventional views on how noise impacts animal communication by establishing informational masking as a general communication problem shared by humans and other animals. These results highlight the need to distinguish between energetic and informational masking to understand the evolution of signaling in complex acoustic environments.

neuroscience↗

bioRxiv2022

The maternal X chromosome impairs cognition and accelerates brain aging through epigenetic modulation in female mice

Female mammalian cells harbor two X chromosomes, one of maternal and one of paternal origin. During development, one X randomly inactivates1-4. This renders either the maternal or paternal X active, causing X mosaicism that varies among individual females, with some showing considerable or complete skew in the general female population5-7. Parent-of-X-origin can modify epigenetics via DNA methylation8, 9 and possibly gene expression; thus, mosaicism could buffer dysregulated processes in aging and disease. However, whether X skewing - or its mosaicism - alters functions in females is largely unknown. Here we tested whether skew toward the maternal X (Xm) influences key functions of the body. Among cardiac, bone, metabolic, and brain functions, Xm selectively impaired cognition in female mice throughout the lifespan. Cognitive deficits were accompanied by Xm-mediated acceleration of biologic or epigenetic aging of the female hippocampus, a key center for learning and memory. Xm showed epigenetic imprinting of several genes within hippocampal neurons, suggesting silenced cognitive loci. Thus, the maternal X chromosome impaired cognition, accelerated brain aging, and silenced genes. Understanding how the maternal X impairs brain function could lead to new understanding of female heterogeneity in cognitive heath and to X chromosome-derived pathways against cognitive deficits and brain aging.

neuroscience↗

bioRxiv2022

Single-cell analysis reveals the range of transcriptional states of circulating human neutrophils

Neutrophils are the most abundant leukocytes in human blood and are essential components of innate immunity. Until recently, neutrophils were considered homogeneous and transcriptionally inactive cells, but both concepts are being challenged. To date, neutrophils have been characterized based on discrete parameters including cell-surface markers, buoyancy, maturation status, or tissue localization. Single-cell RNA sequencing (scRNA-seq) offers an unbiased view of cells along a continuum of transcriptional states. However, the use of scRNA-seq to characterize neutrophils has proven technically difficult, explaining in part the paucity of published single-cell data on neutrophils. We have found that modifications to the data analysis pipeline, rather than to the existing scRNA-seq chemistries, can significantly increase the detection of human neutrophils in scRNA-seq. We have then applied a modified pipeline to the study of human peripheral blood neutrophils. Our findings indicate that circulating human neutrophils are transcriptionally heterogeneous cells, which can be classified into one of four transcriptional clusters that are reproducible among healthy human subjects. We demonstrate that peripheral blood neutrophils shift from relatively immature (Nh0) cells, through a transitional phenotype (Nh1), into one of two endpoints defined by either relative transcriptional inactivity (Nh2) or high expression of type I interferon-inducible genes (Nh3). Transitions among states are characterized by the expression of specific transcription factors. By simultaneously measuring surface proteins and intracellular transcripts at the single-cell level, we show that these transcriptional subsets are independent of the canonical surface proteins that are commonly used to define and characterize human neutrophils. These findings provide a new view of human neutrophil heterogeneity, with potential implications for the characterization of neutrophils in health and disease.

immunology↗

bioRxiv2022

Single extracellular vesicle analysis in human amniotic fluid shows evidence of phenotype alterations in preeclampsia

Amniotic fluid surrounding the developing fetus is a complex biological fluid rich in metabolically active bio-factors. The presence of extracellular vesicles (EVs) in amniotic fluid has been mainly related to fetal urine. We here characterized EVs from term amniotic fluid in terms of surface marker expression using different orthogonal techniques. EVs appeared to be a heterogeneous population expressing markers of renal, placental, epithelial and stem cells. Moreover, we compared amniotic fluid EVs from normal pregnancies with those of preeclampsia, a hypertensive disorder affecting up to 8% of pregnancies worldwide. An increase of CD105 (endoglin) expressing EVs was observed in preeclamptic amniotic fluid by bead-based cytofluorimetric analysis, and further confirmed using a chip-based analysis. HLA-G, a typical placental marker, was not co-expressed by the majority of CD105+ EVs, suggesting their origin from amniotic fluid cells. At a functional level, preeclampsia-derived EVs, but not normal pregnancy EVs, showed an antiangiogenic effect, possibly due to the decoy effect of endoglin. In addition, several miRNAs were differentially expressed in preeclampsia-derived EVs and directly related to the modulation of angiogenesis and trophoblast function. Our results provide a characterization of term amniotic fluid-EVs, supporting their origin from fetal and placental cells. In preeclampsia, the observed antiangiogenic characteristics of amniotic fluid-EVs may reflect the hypoxic and antiangiogenic microenvironment and could possibly impact on the developing fetus or on the surrounding fetal membranes.

molecular biology↗

bioRxiv2022

Presence of sodium taurocholate co-transporting polypeptide and Hepatitis B replication marker on placenta: Another home for the virus

BackgroundThe role of sodium taurocholate co-transporting polypeptide (NTCP), in facilitating the binding of Hepatitis B virus (HBV) on surface of hepatocytes is well documented. Expression of NTCP in extra hepatic cells may make these cells susceptible to HBV infection and support cellular proliferation akin to hepatocytes. Placental replication of HBV is not well explored. In this study we have assessed the expression of NTCP and HBV replication markers (HBeAg, HBcAg, and HBV DNA) in placental cells, to investigate if these cells act as host for HBV. MethodsFourty one HBsAg+ve pregnant women along with 10 healthy controls were enrolled after obtaining informed consent. The HBV DNA in placenta was detected by qPCR using primers for X and core ORF. Expression of NTCP in placenta was analyzed by qRT-PCR and further investigated by immunohistochemistry (IHC) along with HBV replication biomarkers, HBeAg, and HBcAg. ResultsHBsAg positive subjects were divided in two groups on the basis of viral load [High Viral Load (HVL) Group; viral load [≥] 2000IU/ml, Low Viral Load (LVL) Group; viral load <2000IU/ml] according to INASL guidelines 2018. HBV infected females showed increased expression of NTCP in trophoblasts of placenta compared to control group (HVL 3.69{+/-}0.13 Vs Control 1.74{+/-}0.15, p=0.0117). Furthermore, significant difference in NTCP expression was also observed between HVL and LVL group (HVL 3.69{+/-}0.13 Vs LVL 1.98{+/-}0.17, p=0.022) and positively correlated with the maternal HBV DNA load. Membranous and/or cytoplasmic immunostaining of NTCP, and cytoplasmic staining of HBeAg and HBcAg in trophoblasts along with presence of HBV DNA indicated that trophoblasts are not only susceptible to HBV infection but may also be a site for viral replication. ConclusionsThis is the pioneer study, which demonstrates expression of NTCP on placenta which may facilitate the entry of HBV. Furthermore, the study establishes the presence of HBeAg in placenta of patients without circulating HBeAg, indicating these cells may act as replication host/reservoir. This pioneering finding hints at the possibility of exploring the potential of NTCP blocking strategies in preventing vertical transmission of HBV.

microbiology↗