PSPC1 Binds to HCV IRES and Prevents Ribosomal Protein S5 Binding, Inhibiting Viral RNA Translation.

Hepatitis C virus (HCV) infects the human liver, and its chronic infection is one of the major causes of Hepatocellular carcinoma. Translation of HCV RNA is mediated by an Internal Ribosome Entry Site (IRES) element located in the 5'UTR of viral RNA. Several RNA Binding proteins of the host interact with the HCV IRES and modulate its function. Here, we demonstrate that PSPC1 (Paraspeckle Component 1), an essential paraspeckle component, upon HCV infection is relocalized and interacts with HCV IRES to prevent viral RNA translation. Competition UV-crosslinking experiments showed that PSPC1 interacts explicitly with the SLIV region of the HCV IRES, which is known to play a vital role in ribosomal loading to the HCV IRES via interaction with Ribosomal protein S5 (RPS5). Partial silencing of PSPC1 increased viral RNA translation and, consequently, HCV replication, suggesting a negative regulation by PSPC1. Interestingly, the silencing of PSPC1 protein leads to an increased interaction of RPS5 at the SLIV region, leading to an overall increase in the viral RNA in polysomes. Overall, our results showed how the host counters viral infection by relocalizing nuclear protein to the cytoplasm as a survival strategy.

Comprehensive characterization of unscientifically disposed municipal solid waste (MSW) in Kashmir Region, India.

Unscientific dumping of municipal solid waste (MSW) is a common practice in Kashmir. To have an environmentally friendly and sustainable waste management system, MSW was collected from nine study locations of this region. They were air-dried, then oven-dried at 105 °C for 24 h, segregated, and characterized for various components. The overall average organic waste was > 55%, plastic waste about 17%, inert material about 10%, paper 9%, and cloth waste 7%. The calorific value of paper and plastic wastes exhibited was 4910 kcal/kg, while organic waste had a calorific value of 1980 kcal/kg. The proximate analysis showed that the moisture content ranged from 16 to 29%, volatile matter ranged from 49 to 72%, ash content ranged from 0.03 to 5%, and fixed carbon ranged from 5 to 20%. In S7, the volatile matter content recorded the lowest value at 49.15%, while in S5, the volatile matter content was notably higher at 71.84%, indicating easier ignition. Further, elemental analysis revealed that the major elements in MSW were carbon and oxygen, 53% and 37%, respectively, with small traces of heavy metals with an average of 0.02% cadmium (Cd) and 0.006% lead (Pb). Moreover, field emission scanning electron microscopy (FESEM) micrographs provided confirmation that the majority of components in the MSW exhibited either partial or complete degradation, resulting in a rough surface texture. In addition, the presence of silica and other silicate groups was also detected. Fourier transform infrared spectroscopy (FT-IR) analysis revealed that the main functional groups were alcohol. In the X-ray diffraction (XRD) analysis, all the major mineral phases were detected between 20 and 30° 2θ, except for the peaks at 50-60° 2θ in S3 and S9 where catalysts such as zeolite Y and zeolite X were detected. Overall, the MSW had low moisture content but higher calorific value, making it a viable feedstock.

p53 and RNA viruses: The tug of war.

Host factors play essential roles in viral infection, and their interactions with viral proteins are necessary for establishing effective pathogenesis. p53 is a host factor that maintains genomic integrity by controlling cell-cycle progression and cell survival. It is a well-known tumor suppressor protein that gets activated by various stress signals, thereby regulating cellular pathways. The cellular outcomes from different stresses are tightly related to p53 dynamics, including its alterations at gene, mRNA, or protein levels. p53 also contributes to immune responses leading to the abolition of viral pathogens. In turn, the viruses have evolved strategies to subvert p53-mediated host responses to improve their life cycle and pathogenesis. Some viruses attenuate wild-type p53 (WT-p53) function for successful pathogenesis, including degradation and sequestration of p53. In contrast, some others exploit the WT-p53 function through regulation at the transcriptional/translational level to spread infection. One area in which the importance of such host factors is increasingly emerging is the positive-strand RNA viruses that cause fatal viral infections. In this review, we provide insight into all the possible mechanisms of p53 modulation exploited by the positive-strand RNA viruses to establish infection. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Translation > Regulation RNA in Disease and Development > RNA in Disease.

Hepatitis C virus non-structural proteins modulate cellular kinases for increased cytoplasmic abundance of host factor HuR and facilitate viral replication.

Host protein HuR translocation from nucleus to cytoplasm following infection is crucial for the life cycle of several RNA viruses including hepatitis C virus (HCV), a major causative agent of hepatocellular carcinoma. HuR assists the assembly of replication-complex on the viral-3'UTR, and its depletion hampers viral replication. Although cytoplasmic HuR is crucial for HCV replication, little is known about how the virus orchestrates the mobilization of HuR into the cytoplasm from the nucleus. We show that two viral proteins, NS3 and NS5A, act co-ordinately to alter the equilibrium of the nucleo-cytoplasmic movement of HuR. NS3 activates protein kinase C (PKC)-δ, which in-turn phosphorylates HuR on S318 residue, triggering its export to the cytoplasm. NS5A inactivates AMP-activated kinase (AMPK) resulting in diminished nuclear import of HuR through blockade of AMPK-mediated phosphorylation and acetylation of importin-α1. Cytoplasmic retention or entry of HuR can be reversed by an AMPK activator or a PKC-δ inhibitor. Our findings suggest that efforts should be made to develop inhibitors of PKC-δ and activators of AMPK, either separately or in combination, to inhibit HCV infection.

Abundance and characteristics of microplastics in a freshwater river in northwestern Himalayas, India - Scenario of riverbank solid waste disposal sites.

Microplastics (MPs) are one of the challenging and established contaminants that have adverse implications on human health. The focus of this study was to quantify and analyze the contribution of unscientific municipal solid waste (MSW) disposal sites to the MPs in the Jhelum River and the risk associated with it. Quantitative analysis of our study showed a mean MP concentration of 1474 ± 1026 particles/m3 for the entire stretch of the river. All the sites confirmed the presence of MPs with the concentration ranging from 600 particles/m3 to 2500 particles/m3. The size distribution of MPs suggested that 34 % of the microplastics ranged between 300 µm to 75 µm while 66 % of the particles varied between 300 µm to 5 mm. The concentrations of MPs downstream of unscientific disposal sites were found to increase threefold to that of upstream. The Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the presence of polyethylene (PE) in the majority followed by polyvinyl chloride (PVC) and polypropylene (PP). The flakes were dominant throughout the river followed by filaments, fragments, and spherules. Count based Pollution level indexing (PLI) estimated 3-14 times MP contamination in the river with respect to contamination in glacial runoffs. The risk assessment study of the MPs indicated an increase of around 10.2 % in ingestion rates of MPs due to the unscientific disposal of MSW on the banks of the freshwater body. The values of polymer hazard index (PHI) and potential ecological risk index (PERI) were in the extreme case of pollution (PHI>1000 and PERI>1200). This study manifests the adversities of unscientific municipal solid waste disposal for timely waste management.

LncRNA NEAT1 regulates HCV-induced Hepatocellular carcinoma by modulating the miR-9-BGH3 axis.

Chronic hepatitis C virus (HCV) infection is a leading cause of end-stage liver diseases, such as fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Several cellular entities, including paraspeckles and their related components, are involved in viral pathogenesis and cancer progression. NEAT1 lncRNA is a major component of paraspeckles that has been linked to several malignancies. In this study, analysis of the Cancer Genome Atlas (TCGA) database and validation in HCV-induced HCC tissue and serum samples showed significantly high expression of NEAT1 in patients with liver cancer. Moreover, we found that NEAT1 levels increased upon HCV infection. To further understand the mechanism of NEAT1-induced HCC progression, we selected one of its targets, miR-9-5 p, which regulates BGH3 mRNA levels. Interestingly, miR-9-5 p levels were downregulated upon HCV infection, whereas BGH3 levels were upregulated. Additionally, partial NEAT1 knockdown increased miR-9-5 p levels and decreased BGH3 levels, corroborating our initial results. BGH3 levels were also upregulated in HCV-induced HCC and TCGA tissue samples, which could be directly correlated with NEAT1 levels. As a known oncogene, BGH3 is directly linked to HCC progression mediated by NEAT1. We also found that NEAT1 levels remained upregulated in serum samples from patients treated with direct-acting antivirals (DAA), indicating that NEAT1 might be a molecular trigger that promotes HCC development. Collectively, these findings provide molecular insights into HCV-induced HCC progression via the NEAT1-miR-9-BGH3 axis.

Genetic algorithm optimized node deployment in IEEE 802.15.4 potato and wheat crop monitoring infrastructure.

This proposal investigates the effect of vegetation height and density on received signal strength between two sensor nodes communicating under IEEE 802.15.4 wireless standard. With the aim of investigating the path loss coefficient of 2.4 GHz radio signal in an IEEE 802.15.4 precision agriculture monitoring infrastructure, measurement campaigns were carried out in different growing stages of potato and wheat crops. Experimental observations indicate that initial node deployment in the wheat crop experiences network dis-connectivity due to increased signal attenuation, which is due to the growth of wheat vegetation height and density in the grain-filling and physical-maturity periods. An empirical measurement-based path loss model is formulated to identify the received signal strength in different crop growth stages. Further, a NSGA-II multi-objective evolutionary computation is performed to generate initial node deployment and is optimized over increased coverage, reduced over-coverage, and received signal strength. The results show the development of a reliable wireless sensor network infrastructure for wheat crop monitoring.

Regulation of miR-186-YY1 axis by the p53 translational isoform ∆40p53: implications in cell proliferation.

We have earlier shown that p53-FL and its translational isoform ∆40p53 are differentially regulated. In this study, we have investigated the cellular effect of ∆40p53 regulation on downstream gene expression, specifically miRNAs. Interestingly, ∆40p53 showed antagonistic regulation of miR-186-5p as compared to either p53 alone or a combination of both the isoforms. We have elucidated the miR-186-5p mediated effect of ∆40p53 in cell proliferation. Upon expression of ∆40p53, we observed a significant decrease in YY1 levels, an established target of miR-186-5p, which is involved in cell proliferation. Further assays with anti-miR-186 established the interdependence of ∆40p53- miR-186-5p-YY1- cell proliferation. The results unravel a new dimension toward the understanding of ∆40p53 functions, which seems to regulate cellular fate independent of p53FL.

lncRNA HULC facilitates efficient loading of HCV-core protein onto lipid droplets and subsequent virus-particle release.

The cellular lipid pool plays a central role in hepatitis C virus (HCV) life cycle, from establishing infection to virus propagation. Here, we show that a liver abundant long noncoding RNA, highly upregulated in liver carcinoma (HULC), is upregulated during HCV infection and manipulates the lipid pool to favour virus life cycle. Interestingly, HULC was found to be crucial for the increase in number of lipid droplets in infected cells. This effect was attributed to the role of HULC in lipid biogenesis. Further, we demonstrated that HULC knockdown decreases the association of HCV-core protein with lipid droplets. This exhibited a direct consequence on the release of HCV particles. The role of HULC in HCV-particle release was further substantiated by additional knockdown and mutation experiments. Additionally, we found that increased level of HULC in HCV-infected cells was a result of Retinoid X Receptor Alpha (RXRA)-mediated transcription, which seemed to be aided by HCV-core protein. Taken together, the results identify a distinct role of long noncoding RNA HULC in lipid dynamics during HCV infection, which provides new insights into the complex process of HCV propagation and pathogenesis.

Arsenic Attenuates Heparin-Binding EGF-Like Growth Factor/EGFR Signaling That Promotes Matrix Metalloprotease 9-Dependent Astrocyte Damage in the Developing Rat Brain.

We earlier reported that exposure to arsenic at concentrations in ground water of India attenuated glial fibrillary acidic protein (GFAP) during brain development. Here, we validated the effects and explored mechanism in cultured astrocytes and developing rat brain. We hypothesized participation of epidermal growth factor receptor (EGFR), known to regulate GFAP. We found that arsenic inactivated EGFR, marked by reduced phospho-EGFR in astrocytes. Screening EGFR ligands revealed an arsenic-mediated attenuation in cellular and secreted-Heparin-binding EGF-like growth factor (HB-EGF). Furthermore, we observed that recombinant-HB-EGF cotreatment with arsenic blocked reduction in HB-EGF, secreted-HB-EGF and phospho-EGFR, which could be reversed by EGFR-inhibitor, gefitinib, suggesting that arsenic attenuated an HB-EGF/EGFR loop in astrocytes. This reduced HB-EGF/EGFR was essentially responsible for arsenic-induced astrocyte damage, obvious from a recombinant-HB-EGF-mediated recovery in GFAP levels and astrocyte morphology and reduction in astrocyte apoptosis, and the reverse by gefitinib. We found that arsenic also suppressed neuronal HB-EGF levels, which additionally contributed towards astrocyte damage. Exploring the pathways downstream of reduced HB-EGFR/EGFR revealed that an upregulated matrix metalloproteinase 9 (MMP9) within the astrocytes ultimately led to apoptosis and GFAP loss. Astrocytes and MMPs are known to regulate the blood-brain barrier (BBB) integrity, and hence we examined the effects of arsenic on BBB. We detected an arsenic-mediated increased BBB permeability, which could be blocked by recombinant-HB-EGF and MMP9 inhibitor, SB-3CT. Thus, our study indicates that via reduced astrocyte and neuronal HB-EGF signaling, arsenic may induce MMP9 levels and GFAP loss in astrocytes, which might adversely affect BBB integrity of the developing rat brain.

Arsenic, Cadmium, and Lead Like Troglitazone Trigger PPARγ-Dependent Poly (ADP-Ribose) Polymerase Expression and Subsequent Apoptosis in Rat Brain Astrocytes.

We previously demonstrated that arsenic, cadmium, and lead mixture at environmentally relevant doses induces astrocyte apoptosis in the developing brain. Here, we investigated the mechanism and contribution of each metal in inducing the apoptosis. We hypothesized participation of transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ), reported to affect astrocyte survival. We treated cultured rat astrocytes with single metals and their combinations and performed apoptosis assay and measured PPARγ expression levels. We found that cadmium demonstrated maximum increase in PPARγ as well as apoptosis, followed by arsenic and then lead. Interestingly, we observed that the metals mimicked PPARγ agonist, troglitazone, and enhanced PPARγ-transcriptional activity. Co-treatment with PPARγ-siRNA or PPARγ-antagonist, GW9662, suppressed the astrocyte apoptosis, suggesting a prominent participation of PPARγ in metal(s)-induced astrocyte loss. We explored PPARγ-transcriptional activity and identify its target gene in apoptosis, performed in silico screening. We spotted PPARγ-response elements (PPREs) within poly(ADP-ribose) polymerase (PARP) gene, and through gel-shift assay verified metal(s)-mediated increased PPARγ binding to PARP-PPREs. Chromatin-immunoprecipitation and luciferase-reporter assays followed by real-time PCR and Western blotting proved PPRE-mediated PARP expression, where cadmium contributed most and lead least, and the effects of metal mixture were comparable with troglitazone. Eventually, dose-dependent increased cleaved-PARP/PARP ratio confirmed astrocyte apoptosis. Additionally, we found that PPARγ and PARP expressions were c-Jun N-terminal kinases and cyclin-dependent kinase5-dependent. In vivo treatment of developing rats with the metals corroborated enhanced PPARγ-dependent PARP and astrocyte apoptosis, where yet again cadmium contributed most. Overall, our study enlightens a novel PPARγ-dependent mechanism of As-, Cd-, and Pb-induced astrocyte apoptosis.

Docosahexaenoic acid up-regulates both PI3K/AKT-dependent FABP7-PPARγ interaction and MKP3 that enhance GFAP in developing rat brain astrocytes.

The astrocyte marker, glial fibrillary acidic protein (GFAP), has essential functions in the brain, but may trigger astroglial scarring when expressed in excess. Docosahexaenoic acid (DHA) is an n-3 fatty acid that is protective during brain development. However, the effect of DHA on GFAP levels of developing brain remains unexplored. Here, we detected that treating developing rats with DHA-enriched fish-oil caused dose-dependent GFAP augmentation. We investigated the mechanism promoting GFAP, hypothesizing the participation of fatty acid-binding protein-7 (FABP7), known to bind DHA. We identified that DHA stimulated FABP7 expression in astrocytes, and FABP7-silencing suppressed DHA-induced GFAP, indicating FABP7-mediated GFAP increase. Further investigation proved FABP7 expression to be phosphatidylinositide 3-kinases (PI3K)/AKT and nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARγ)-dependent. We found that PI3K/AKT activated PPARγ that triggered FABP7 expression via PPARγ-responsive elements within its gene. Towards identifying FABP7-downstream pathways, we considered our previous report that demonstrated cyclin-dependent kinase-5 (CDK5)-PPARγ-protein-protein complex to suppress GFAP. We found that the DHA-induced FABP7 underwent protein-protein interaction with PPARγ, which impeded CDK5-PPARγ formation. Hence, it appeared that enhanced FABP7-PPARγ in lieu of CDK5-PPARγ resulted in increased GFAP. PI3K/AKT not only stimulated formation of FABP7-PPARγ protein-protein complex, but also up-regulated a FABP7-independent MAP-kinase-phosphatase-3 pathway that inactivated CDK5 and hence attenuated CDK5-PPARγ. Overall, our data reveal that via the proximal PI3K/AKT, DHA induces FABP7-PPARγ, through genomic and non-genomic mechanisms, and MAP-kinase-phosphatase-3 that converged at attenuated CDK5-PPARγ and therefore, enhanced GFAP. Accordingly, our study demonstrates a DHA-mediated astroglial hyperactivation, pointing toward a probable injurious role of DHA in brain development.

Exposure to As-, Cd-, and Pb-mixture induces Aß, amyloidogenic APP processing and cognitive impairments via oxidative stress-dependent neuroinflammation in young rats.

Environmental pollutants act as risk factors for Alzheimer's disease (AD), mainly affecting the aging population. We investigated early manifestations of AD-like pathology by a mixture of arsenic (As), cadmium (Cd), and lead (Pb), reported to impair neurodevelopment. We treated rats with As+Cd+Pb at their concentrations detected in groundwater of India, ie, 0.38, 0.098, and 0.22 ppm or 10 times of each, respectively, from gestation-05 to postnatal day-180. We identified dose-dependent increase in amyloid-beta (Aß) in frontal cortex and hippocampus as early as post-weaning. The effect was strongly significant during early-adulthood, reaching levels comparable to an Aß-infused AD-like rat model. The metals activated the proamyloidogenic pathway, mediated by increase in amyloid precursor protein (APP), and subsequent beta secretase (BACE) and presenilin (PS)-mediated APP-processing. Investigating the mechanism of Aß-induction revealed an augmentation in oxidative stress-dependent neuroinflammation that stimulated APP expression through interleukin-responsive-APP-mRNA 5'-untranslated region. We then examined the effects of individual metals and binary mixtures in comparison with the tertiary. Among individual metals, Pb triggered maximum induction of Aß, whereas individual As or Cd had a relatively non-significant effect on Aß despite enhanced APP, owing to reduced induction of BACE and PS. Interestingly, when combined the metals demonstrated synergism, with a major contribution by As. The synergistic effect was significant and consistent in tertiary mixture, resulting in the augmentation of Aß. Eventually, increase in Aß culminated in cognitive impairments in the young rats. Together, our data demonstrate that exposure to As+Cd+Pb induces premature manifestation of AD-like pathology that is synergistic, and oxidative stress and inflammation dependent.

Exposure to As, Cd and Pb-mixture impairs myelin and axon development in rat brain, optic nerve and retina.

Arsenic (As), lead (Pb) and cadmium (Cd) are the major metal contaminants of ground water in India. We have reported the toxic effect of their mixture (metal mixture, MM), at human relevant doses, on developing rat astrocytes. Astrocyte damage has been shown to be associated with myelin disintegration in CNS. We, therefore, hypothesized that the MM would perturb myelinating white matter in cerebral cortex, optic nerve (O.N.) and retina. We observed modulation in the levels of myelin and axon proteins, such as myelin basic protein (MBP), proteolipid protein, 2'-, 3'-cyclic-nucleotide-3'-phosphodiesterase, myelin-associated glycoprotein and neurofilament (NF) in the brain of developing rats. Dose and time-dependent synergistic toxic effect was noted. The MBP- and NF-immunolabeling, as well as luxol-fast blue (LFB) staining demonstrated a reduction in the area of intact myelin-fiber, and an increase in vacuolated axons, especially in the corpus-callosum. Transmission electron microscopy (TEM) of O.N. revealed a reduction in myelin thickness and axon-density. The immunolabeling with MBP, NF, and LFB staining in O.N. supported the TEM data. The hematoxylin and eosin staining of retina displayed a decrease in the thickness of nerve-fiber, plexiform-layer, and retinal ganglion cell (RGC) count. Investigating the mechanism revealed a loss in glutamine synthetase activity in the cerebral cortex and O.N., and a fall in the brain derived neurotrophic factor in retina. An enhanced apoptosis in MBP, NF and Brn3b-containing cells justified the diminution in myelinating axons in CNS. Our findings for the first time indicate white matter damage by MM, which may have significance in neurodevelopmental-pediatrics, neurotoxicology and retinal-cell biology.

A study on oxidative stress and antioxidant status of agricultural workers exposed to organophosphorus insecticides during spraying.

Oxidative stress status and Acetylcholinesterase (AChE) activity were studied in blood samples obtained from 61 agricultural workers engaged in spraying organophosphorus (OP) insecticides in the mango plantation, with a minimum work history of one year, in the age range of 12-55 years. Controls were age-matched, unexposed workers, who never had any exposure to OP pesticides. They were evaluated for oxidative stress markers MDA (end product of lipid peroxidation), reduced glutathione (GSH), and Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) levels in blood. The results showed a marked inhibition of the AChE and BChE activities in the sprayers as compared to the controls. The malondialdehyde(MDA), the last product of lipid peroxidation was found to be increased significantly in sprayers(p<0.05), while depletion in the concentration of antioxidant glutathione(GSH) was also observed in the sprayers but the difference was statistically not significant. It was concluded on the basis of biochemical analysis that pesticides sprayers are exposed to more oxidative stress as evidenced by the changes in antioxidant status. The measurement of the AChE and BChE activities in agricultural workers who spray OPs could be a good biomonitoring factor and is recommended to be performed on a regular basis.

Occupational health risks among the workers employed in leather tanneries at Kanpur.

In a cross-sectional study, a random sample of 197 male workers drawn from different sections of 10 leather tanneries in Kanpur were selected for the assessment of health risks. A control group comprising of 117 male subjects belonging to a similar age group and socioeconomic strata, who never had any occupational exposure in the leather tanneries, were also examined for the comparison purpose. The findings revealed a significantly higher prevalence of morbidity among the exposed workers in contrast to that observed in the controls (40.1% vs. 19.6%). The respiratory diseases (16.7%) were mainly responsible for a higher morbidity among the exposed workers whereas the gastrointestinal tract problems were predominant in the control group. The urinary and blood samples collected from the exposed group showed significantly higher levels of chromium, thereby reflecting the body burden of Cr in the exposed workers as a result of a high concentration of environmental Cr at the work place.