Publications by authors named "Lakmini S Premadasa"

The epigenetic mechanisms driving persistent gastrointestinal mucosal dysfunction in HIV/SIV infection is an understudied topic. Using reduced-representation bisulfite sequencing, we identified HIV/SIV infection in combination anti-retroviral therapy (cART)-naive rhesus macaques (RMs) to induce marked hypomethylation throughout promoter-associated CpG islands (paCGIs) in genes related to inflammatory response ( ), cellular adhesion and proliferation in colonic epithelial cells (CEs). Moreover, low-dose delta-9-tetrahydrocannabinol (THC) administration reduced NLRP6 protein expression in CE by hypermethylating the paCGI and blocked polyI:C induced NLRP6 upregulation in vitro.

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Article Synopsis
  • Epitranscriptomic modifications, like N6-methyladenosine (m6A) methylation, play a key role in regulating gene expression and have implications in diseases such as cancer and inflammation.
  • In this study, researchers found that m6A modifications in miRNAs from the brains of Rhesus Monkeys vary based on whether they were uninfected or infected with SIV and treated with anti-retroviral therapy or THC:CBD.
  • The findings suggest that THC:CBD treatments lower m6A methylation in specific miRNAs that target proinflammatory genes, potentially explaining beneficial effects on neuroinflammation in diseases such as Alzheimer’s and Parkinson’s.
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  • * ECs from uninfected macaques and SIV-infected macaques significantly enhance latent HIV transcription and viral antigen expression, while ECs treated with THC inhibit these effects.
  • * Long-term THC treatment alters ECs' properties, leading to reduced inflammatory responses and diminished ability to reactivate latent HIV, suggesting a complex interaction between ECs and HIV persistence mechanisms.
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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.

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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).

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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).

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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.

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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).

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Article Synopsis
  • The study investigates the relationship between selenium and RNA viruses, specifically focusing on how the Zika virus (ZIKV) may impact selenoproteins that are crucial for brain health, especially in neonates.
  • Researchers found that ZIKV can bind to key human selenoprotein mRNAs, particularly those coding for thioredoxin reductase (TXNRD1) and selenoprotein P (SELENOP), leading to significant reductions in their protein levels after infection.
  • The findings imply that ZIKV may mimic the effects of a genetic disorder that inhibits selenoprotein synthesis, potentially causing severe neurological issues like microcephaly in infants through mechanisms unrelated
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