Determining dengue infection risk in the Colombo district of Sri Lanka by inferencing the genetic parameters of Aedes mosquitoes.

BACKGROUND: For decades, dengue has posed a significant threat as a viral infectious disease, affecting numerous human lives globally, particularly in tropical regions, yet no cure has been discovered. The genetic trait of vector competence in Aedes mosquitoes, which facilitates dengue transmission, is difficult to measure and highly sensitive to environmental changes. METHODS: In this study we attempt, for the first time in a non-laboratory setting, to quantify the vector competence of Aedes mosquitoes assuming its homogeneity across both species; aegypti and albopictus and across the four Dengue serotypes. Estimating vector competence in relation to varying rainfall patterns was focused in this study to showcase the changes in this vector trait with respect to environmental variables. We quantify it using an existing mathematical model originally developed for malaria in a Bayesian inferencing setup. We conducted this study in the Colombo district of Sri Lanka where the highest number of human populations are threatened with dengue. Colombo district experiences continuous favorable temperature and humidity levels throughout the year creating ideal conditions for Aedes mosquitoes to thrive and transmit the Dengue disease. Therefore we only used the highly variable and seasonal rainfall as the primary environmental variable as it significantly influences the number of breeding sites and thereby impacting the population dynamics of Aedes. RESULTS: Our research successfully deduced vector competence values for the four identified seasons based on Monsoon rainfalls experienced in Colombo within a year. We used dengue data from 2009 - 2022 to infer the estimates. These estimated values have been corroborated through experimental studies documented in the literature, thereby validating the malaria model to estimate vector competence for dengue disease. CONCLUSION: Our research findings conclude that environmental conditions can amplify vector competence within specific seasons, categorized by their environmental attributes. Additionally, the deduced vector competence offers compelling evidence that it impacts disease transmission, irrespective of geographical location, climate, or environmental factors.

Cannabinoids modulate the microbiota-gut-brain axis in HIV/SIV infection by reducing neuroinflammation and dysbiosis while concurrently elevating endocannabinoid and indole-3-propionate levels.

BACKGROUND: Although the advent of combination anti-retroviral therapy (cART) has transformed HIV into a manageable chronic disease, an estimated 30-50% of people living with HIV (PLWH) exhibit cognitive and motor deficits collectively known as HIV-associated neurocognitive disorders (HAND). A key driver of HAND neuropathology is chronic neuroinflammation, where proinflammatory mediators produced by activated microglia and macrophages are thought to inflict neuronal injury and loss. Moreover, the dysregulation of the microbiota-gut-brain axis (MGBA) in PLWH, consequent to gastrointestinal dysfunction and dysbiosis, can lead to neuroinflammation and persistent cognitive impairment, which underscores the need for new interventions. METHODS: We performed RNA-seq and microRNA profiling in basal ganglia (BG), metabolomics (plasma) and shotgun metagenomic sequencing (colon contents) in uninfected and SIV-infected rhesus macaques (RMs) administered vehicle (VEH/SIV) or delta-9-tetrahydrocannabinol (THC) (THC/SIV). RESULTS: Long-term, low-dose THC reduced neuroinflammation and dysbiosis and significantly increased plasma endocannabinoid, endocannabinoid-like, glycerophospholipid and indole-3-propionate levels in chronically SIV-infected RMs. Chronic THC potently blocked the upregulation of genes associated with type-I interferon responses (NLRC5, CCL2, CXCL10, IRF1, IRF7, STAT2, BST2), excitotoxicity (SLC7A11), and enhanced protein expression of WFS1 (endoplasmic reticulum stress) and CRYM (oxidative stress) in BG. Additionally, THC successfully countered miR-142-3p-mediated suppression of WFS1 protein expression via a cannabinoid receptor-1-mediated mechanism in HCN2 neuronal cells. Most importantly, THC significantly increased the relative abundance of Firmicutes and Clostridia including indole-3-propionate (C. botulinum, C. paraputrificum, and C. cadaveris) and butyrate (C. butyricum, Faecalibacterium prausnitzii and Butyricicoccus pullicaecorum) producers in colonic contents. CONCLUSION: This study demonstrates the potential of long-term, low-dose THC to positively modulate the MGBA by reducing neuroinflammation, enhancing endocannabinoid levels and promoting the growth of gut bacterial species that produce neuroprotective metabolites, like indole-3-propionate. The findings from this study may benefit not only PLWH on cART, but also those with no access to cART and more importantly, those who fail to suppress the virus under cART.

Extracellular condensates (ECs) are endogenous modulators of HIV transcription and latency reactivation.

Persistence of human immunodeficiency virus (HIV) latent reservoir is the major challenge to HIV cure because the latent reservoir is not eliminated by antiretroviral therapy (ART), and they serve as sources for viral rebound upon cessation of ART. Mechanisms regulating viral persistence are not well understood. This study used model systems of post-integration latency to explore the role of basal ganglia (BG) isolated extracellular condensates (ECs) in reprogramming HIV latent cells. We found that BG ECs from uninfected macaques (VEH) and SIV infected macaques (VEH|SIV) activate latent HIV transcription in various model systems. VEH and VEH|SIV ECs significantly increased expression of viral antigen in latently infected cells. Activation of viral transcription, antigen expression, and latency reactivation was inhibited by ECs from the brain of macaques treated with Delta-9-tetrahydrocannabinol (THC) and infected with SIV (THC|SIV). Virus produced by latently infected cells treated with VEH|SIV ECs potentiated cell-cell and cell-free HIV transmission. VEH|SIV ECs also reversed dexamethasone-mediated inhibition of HIV transcription while TNFα-mediated reactivation of latency was reversed by THC|SIV ECs. Transcriptome and secretome analyses of total RNA and supernatants from latently infected cells treated with ECs revealed significant alteration in gene expression and cytokine secretion. THC|SIV ECs increased secretion of Th2 and decreased secretion of proinflammatory cytokines. Most strikingly, while VEH/SIV ECs robustly induced HIV RNA in latently HIV-infected cells, long-term low-dose THC administration enriched ECs for anti-inflammatory cargo that significantly diminished their ability to reactivate latent HIV, an indication that ECs are endogenous host factors that may regulate HIV persistence. Highlights: ECs isolated from SIV infected macaques (VEH|SIV ECs) is a positive regulator of LTR-dependent HIV transcription and production of infectious viral particles in vitro.ECs isolated from THC treated SIV infected macaques (THC|SIV ECs) prevents the transcription and reactivation of HIV in latently infected cells and prevents production of viral particles in vitro.ECs reprogram host transcriptome and secretome in manners that or suppress promote reactivation of latent HIV reservoir.The above highlights led to the conclusion that while VEH/SIV ECs robustly induced HIV RNA in latently HIV-infected cells, long-term low-dose THC administration enriched ECs for anti-inflammatory cargo that significantly diminished their ability to reactivate latent HIV.

Therapeutic Potential of Cannabis: A Comprehensive Review of Current and Future Applications.

Historically, cannabis has been valued for its pain-relieving, anti-inflammatory, and calming properties. Ancient civilizations like the Egyptians, Greeks, and Chinese medicines recognized their therapeutic potential. The discovery of the endocannabinoid system, which interacts with cannabis phytoconstituents, has scientifically explained how cannabis affects the human immune system, including the central nervous system (CNS). This review explores the evolving world of cannabis-based treatments, spotlighting its diverse applications. By researching current research and clinical studies, we probe into how cannabinoids like Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) help to manage conditions ranging from chronic pain, persistent inflammation, cancer, inflammatory bowel disease, and neurological disorders to even viral diseases such as Human Immunodeficiency virus (HIV), SARS-CoV-2. and the emerging monkeypox. The long-term recreational use of cannabis can develop into cannabis use disorder (CUD), and therefore, understanding the factors contributing to the development and maintenance of cannabis addiction, including genetic predisposition, neurobiological mechanisms, and environmental influences, will be timely. Shedding light on the adverse impacts of CUD underscores the importance of early intervention, effective treatment approaches, and public health initiatives to address this complex issue in an evolving landscape of cannabis policies and perceptions.

Cannabinoid enhancement of lncRNA MMP25-AS1/MMP25 interaction reduces neutrophil infiltration and intestinal epithelial injury in HIV/SIV infection.

Intestinal epithelial barrier dysfunction, a hallmark of HIV/SIV infection, persists despite viral suppression by combination antiretroviral therapy (cART). Emerging evidence suggests a critical role for long noncoding RNAs (lncRNAs) in maintaining epithelial homeostasis. We simultaneously profiled lncRNA/mRNA expression exclusively in colonic epithelium (CE) of SIV-infected rhesus macaques (RMs) administered vehicle (VEH) or Δ-9-tetrahydrocannabinol (THC). Relative to controls, fewer lncRNAs were up- or downregulated in CE of THC/SIV compared with VEH/SIV RMs. Importantly, reciprocal expression of the natural antisense lncRNA MMP25-AS1 (up 2.3-fold) and its associated protein-coding gene MMP25 (attracts neutrophils by inactivating alpha-1 anti-trypsin/SERPINA1) (down 2.2-fold) was detected in CE of THC/SIV RMs. Computational analysis verified 2 perfectly matched complementary regions and an energetically stable (normalized binding free energy = -0.2626) MMP25-AS1/MMP25 duplex structure. MMP25-AS1 overexpression blocked IFN-γ-induced MMP25 mRNA and protein expression in vitro. Elevated MMP25 protein expression in CE of VEH/SIV but not THC/SIV RMs was associated with increased infiltration by myeloperoxidase/CD11b++ neutrophils (transendothelial migration) and epithelial CD47 (transepithelial migration) expression. Interestingly, THC administered in combination with cART increased MMP25-AS1 and reduced MMP25 mRNA/protein expression in jejunal epithelium of SIV-infected RMs. Our findings demonstrate that MMP25-AS1 is a potentially unique epigenetic regulator of MMP25 and that low-dose THC can reduce neutrophil infiltration and intestinal epithelial injury potentially by downregulating MMP25 expression through modulation of MMP25-AS1.

Selenium-Dependent Read Through of the Conserved 3'-Terminal UGA Stop Codon of HIV-1 nef.

The HIV-1 nef gene terminates in a 3'-UGA stop codon, which is highly conserved in the main group of HIV-1 subtypes, along with a downstream potential coding region that could extend the nef protein by 33 amino acids, if readthrough of the stop codon occurs. Antisense tethering interactions (ATIs) between a viral mRNA and a host selenoprotein mRNA are a potential viral strategy for the capture of a host selenocysteine insertion sequence (SECIS) element (Taylor et al, 2016) [1]. This mRNA hijacking mechanism could enable the expression of virally encoded selenoprotein modules, via translation of in-frame UGA stop codons as selenocysteine (SeC). Here we show that readthrough of the 3'-terminal UGA codon of nef occurs during translation of HIV-1 nef expression constructs in transfected cells. This was accomplished via fluorescence microscopy image analysis and flow cytometry of HEK 293 cells, transfected with engineered GFP reporter gene plasmid constructs, in which GFP can only be expressed by translational recoding of the UGA codon. SiRNA knockdown of thioredoxin reductase 1 (TR1) mRNA resulted in a 67% decrease in GFP expression, presumably due to reduced availability of the components involved in selenocysteine incorporation for the stop codon readthrough, thus supporting the proposed ATI. Addition of 20 nM sodium selenite to the media significantly enhanced stop codon readthrough in the pNefATI1 plasmid construct, by >100%, supporting the hypothesis that selenium is involved in the UGA readthrough mechanism.

Inhibition of selenoprotein synthesis by Zika virus may contribute to congenital Zika syndrome and microcephaly by mimicking SELENOP knockout and the genetic disease PCCA.

Selenium status plays a major role in health impacts of various RNA viruses. We previously reported potential antisense interactions between viral mRNAs and host mRNAs encoding isoforms of the antioxidant selenoprotein thioredoxin reductase (TXNRD). Here, we examine possible targeting of selenoprotein mRNAs by Zika virus (ZIKV), because one of the most devastating outcomes of ZIKV infection in neonates, microcephaly, is a key manifestation of Progressive Cerebello-Cerebral Atrophy (PCCA), a genetic disease of impaired selenoprotein synthesis. Potential antisense matches between ZIKV and human selenoprotein mRNAs were identified computationally, the strongest being against human TXNRD1 and selenoprotein P (SELENOP), a selenium carrier protein essential for delivery of selenium to the brain. Computationally, ZIKV has regions of extensive (~30bp) and stable (ΔE < -50kcal/mol) antisense interactions with both TXNRD1 and SELENOP mRNAs. The core ZIKV/SELENOP hybridization was experimentally confirmed at the DNA level by gel shift assay using synthetic oligonucleotides. In HEK293T cells, using Western blot probes for SELENOP and TXNRD1, ZIKV infection knocked down SELENOP protein expression almost completely, by 99% (p<0.005), and TXNRD1 by ~90% (p<0.05). In contrast, by RT-qPCR, there was no evidence of significant changes in SELENOP and TXNRD1 mRNA levels after ZIKV infection, suggesting that their knockdown at the protein level is not primarily a result of mRNA degradation. These results suggest that knockdown of SELENOP and TXNRD1 by ZIKV in fetal brain, possibly antisense-mediated, could mimic SELENOP knockout, thereby contributing to neuronal cell death and symptoms similar to the genetic disease PCCA, including brain atrophy and microcephaly.