Publications by authors named "Vez Repunte-Canonigo"

Substance use disorder is a major concern, with few therapeutic options. Heparan sulfate (HS) and chondroitin sulfate (CS) interact with a plethora of growth factors and their receptors and have profound effects on cellular signaling. Thus, targeting these dynamic interactions might represent a potential novel therapeutic modality.

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  • - Substance use disorders (SUD) and drug addiction significantly impact public health, particularly among individuals and their communities, with a notable overlap between SUD and human immunodeficiency virus (HIV) infections.
  • - The connection between SUD and HIV is complex, as HIV can increase the risk of SUD through chronic pain treatment, while those with SUD are more likely to contract HIV, highlighting the need for integrated research.
  • - The SCORCH consortium aims to utilize single-cell genomics to examine the interactions between SUD and HIV at a cellular level, leveraging human brain tissue collections and animal models for in-depth study.
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  • The study examines the role of the ghrelin receptor (GHSR) in feeding behaviors and diet-induced obesity (DIO) by comparing global GHSR-KO and wild-type (WT) rats on high-fat and regular diets over 12 months.
  • Findings reveal that GHSR gene deletion protects male rats from DIO, decreases their food intake on high-fat diets, and enhances thermogenesis and brain glucose uptake, while these effects were not observed in female rats.
  • The use of a GHSR inverse agonist reduced food intake induced by ghrelin in males and lower binge-eating in both sexes, indicating GHSR as a potential target for obesity treatments.
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  • - The study explores how the ghrelin receptor (GHSR) influences feeding behaviors and diet-induced obesity (DIO) through research on gene deletion in male and female rats over a year on a high-fat diet (HFD).
  • - Findings indicate that deleting the GHSR gene protects male rats from DIO and decreases their food intake, while having different effects for females.
  • - The research also reveals that GHSR deletion enhances energy burning and alters brain glucose metabolism in males, suggesting GHSR could be a key target for obesity treatments.
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  • * Scientists used a special technique to analyze over 113,000 brain cells and found changes in the way genes work, affecting brain health and inflammation.
  • * The mice that drank alcohol showed gene patterns similar to older mice with severe Alzheimer's, suggesting that alcohol might make Alzheimer's worse.
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Hypocretin/Orexin (HCRT) is a neuropeptide that is associated with both stress and reward systems in humans and rodents. The different contributions of signaling at hypocretin-receptor 1 (HCRT-R1) and hypocretin-receptor 2 (HCRT-R2) to compulsive alcohol drinking are not yet fully understood. Thus, the current studies used pharmacological and viral-mediated targeting of HCRT to determine participation in compulsive alcohol drinking and measured HCRT-receptor mRNA expression in the extended amygdala of both alcohol-dependent and non-dependent male rats.

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  • People with HIV can have worse health problems if they misuse opioids like oxycodone, which is a strong painkiller.
  • In a study with special rats, those with HIV that took a lot of oxycodone showed poor memory and brain damage compared to normal rats.
  • The study found that using too much oxycodone can lead to brain inflammation and worsen health in HIV-positive rats.
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The global crisis of opioid overdose fatalities has led to an urgent search to discover the neurobiological mechanisms of opioid use disorder (OUD). A driving force for OUD is the dysphoric and emotionally painful state (hyperkatifeia) that is produced during acute and protracted opioid withdrawal. Here, we explored a mechanistic role for extrahypothalamic stress systems in driving opioid addiction.

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To generate new mechanistic hypotheses on the pathogenesis and disease progression of neuroHIV and identify novel therapeutic targets to improve neuropsychological function in people with HIV, we investigated host genes and pathway dysregulations associated with brain HIV RNA load in gene expression profiles of the frontal cortex, basal ganglia, and white matter of HIV+ patients. Pathway analyses showed that host genes correlated with HIV expression in all three brain regions were predominantly related to inflammation, neurodegeneration, and bioenergetics. HIV RNA load directly correlated particularly with inflammation genesets representative of cytokine signaling, and this was more prominent in white matter and the basal ganglia.

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The endogenous melanocortin peptide agouti-related protein (AgRP) plays a well-known role in foraging, but its contribution to metabolic regulation is less understood. Mature AgRP has distinct residues for melanocortin receptor binding and heparan sulfate interactions. Here, we show that AgRP increases ad libitum feeding and operant responding for food in mice, decreases oxygen consumption, and lowers body temperature and activity, indicating lower energy expenditure.

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The abuse of stimulants, such as methamphetamine (METH), is associated with treatment non-compliance, a greater risk of viral transmission, and the more rapid clinical progression of immunological and central nervous system human immunodeficiency virus (HIV) disease. The behavioral effects of METH in the setting of HIV remain largely uncharacterized. We used a state-of-the-art paradigm of the escalation of voluntary intravenous drug self-administration in HIV transgenic (Tg) and wildtype rats.

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Aims: The development of novel and more effective medications for alcohol use disorder (AUD) is an important unmet medical need. Drug repositioning or repurposing is an appealing strategy to bring new therapies to the clinic because it greatly reduces the overall costs of drug development and expedites the availability of treatments to those who need them. Probenecid, p-(di-n-propylsulfamyl)-benzoic acid, is a drug used clinically to treat hyperuricemia and gout due to its activity as an inhibitor of the kidneys' organic anion transporter that reclaims uric acid from urine.

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Internal RNA modifications have been known for decades, however their roles in mRNA regulation have only recently started to be elucidated. Here we investigated the most abundant mRNA modification, N6-methyladenosine (m6A) in transcripts from the hippocampus of HIV transgenic (Tg) rats. The distribution of m6A peaks within HIV transcripts in HIV Tg rats largely corresponded to the ones observed for HIV transcripts in cell lines and T cells.

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Substance abuse is a pressing problem with few therapeutic options. The identification of addiction resilience factors is a potential strategy to identify new mechanisms that can be targeted therapeutically. Heparan sulfate (HS) is a linear sulfated polysaccharide that is a component of the cell surface and extracellular matrix.

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The pathogenesis and nosology of HIV-associated neurological disease (HAND) remain incompletely understood. Here, to provide new insight into the molecular events leading to neurocognitive impairments (NCI) in HIV infection, we analyzed pathway dysregulations in gene expression profiles of HIV-infected patients with or without NCI and HIV encephalitis (HIVE) and control subjects. The Gene Set Enrichment Analysis (GSEA) algorithm was used for pathway analyses in conjunction with the Molecular Signatures Database collection of canonical pathways (MSigDb).

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While the brain-derived neurotrophic factor (BDNF) gene and its multiple transcripts have been recognized as a key factor for learning, but the specific involvement of BDNF translated from BDNF transcripts with short-3' untranslated region (short 3' UTR) in learning and memory requires further analysis. In this paper, we present data to show that the transduction of hippocampal CA1 neurons with AAV9-5' UTR-BDNF (short 3' UTR)-IRES-ZsGreen and the subsequent expression of BDNF enhanced the phosphorylation of synaptic plasticity relevant proteins and improved passive avoidance and object location, but not object recognition memory. In addition, BDNF improved the relearning of object location.

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Background: A systems biology approach based on the assembly and interrogation of gene regulatory networks, or interactomes, was used to study neuroadaptation processes associated with the transition to alcohol dependence at the molecular level.

Results: Using a rat model of dependent and non-dependent alcohol self-administration, we reverse engineered a global transcriptional regulatory network during protracted abstinence, a period when relapse rates are highest. We then interrogated the network to identify master regulator genes that mechanistically regulate brain region-specific signatures associated with dependent and non-dependent alcohol self-administration.

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Background: The neurofibromatosis type 1 (Nf1) gene encodes a GTPase activating protein that negatively regulates small GTPases of the Ras family.

Methods: We assessed alcohol-related behaviors including alcohol sensitivity, dependent and nondependent drinking, and basal and alcohol-induced gamma-aminobutyric acid (GABA) release in the central nucleus of the amygdala (CeA) in Nf1 heterozygous null mice (Nf1(+/-)). We also investigated the associations of NF1 polymorphisms with alcohol dependence risk and severity in humans.

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Dopaminergic neurons in the ventral tegmental area (VTA) are well known for mediating the positive reinforcing effects of drugs of abuse. Here we identify in rodents and humans a population of VTA dopaminergic neurons expressing corticotropin-releasing factor (CRF). We provide further evidence in rodents that chronic nicotine exposure upregulates Crh mRNA (encoding CRF) in dopaminergic neurons of the posterior VTA, activates local CRF1 receptors and blocks nicotine-induced activation of transient GABAergic input to dopaminergic neurons.

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Background: A thorough investigation of the neurobiology of HIV-induced neuronal dysfunction and its evolving phenotype in the setting of viral suppression has been limited by the lack of validated small animal models to probe the effects of concomitant low level expression of multiple HIV-1 products in disease-relevant cells in the CNS.

Results: We report the results of gene expression profiling of the hippocampus of HIV-1 Tg rats, a rodent model of HIV infection in which multiple HIV-1 proteins are expressed under the control of the viral LTR promoter in disease-relevant cells including microglia and astrocytes. The Gene Set Enrichment Analysis (GSEA) algorithm was used for pathway analysis.

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Proteoglycans like syndecan-3 have complex signaling roles in addition to their function as structural components of the extracellular matrix. Here, we show that syndecan-3 in the lateral hypothalamus has an unexpected new role in limiting compulsive cocaine intake. In particular, we observe that syndecan-3 null mice self-administer greater amounts of cocaine than wild-type mice.

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We have investigated the expression of chromatin-regulating genes in the prefrontal cortex and in the shell subdivision of the nucleus accumbens during protracted withdrawal in mice with increased ethanol drinking after chronic intermittent ethanol (CIE) vapor exposure and in mice with a history of non-dependent drinking. We observed that the methyl-CpG binding protein 2 (MeCP2) was one of the few chromatin-regulating genes to be differentially regulated by a history of dependence. As MeCP2 has the potential of acting as a broad gene regulator, we investigated sensitivity to ethanol and ethanol drinking in MeCP2(308/) (Y) mice, which harbor a truncated MeCP2 allele but have a milder phenotype than MeCP2 null mice.

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Alcoholism is characterized by a compulsion to seek and ingest alcohol, loss of control over intake, and the emergence of a negative emotional state during abstinence. We hypothesized that sustained activation of neuroendocrine stress systems (e.g.

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Application of transcriptomics approaches to accurately dissected anatomically defined brain regions and individual neuronal populations remains a central focus of current neurobiological investigations. A vast selection of methods and commercial products are currently available that allow one to implement routine gene quantitation and profiling from laser-microdissected brain regions, subregions, and neuronal populations. The present chapter reviews laser microdissection strategies for gene expression analyses, strategies for RNA extraction, reverse transcriptase-coupled PCR (RT-PCR), and target preparation for microarray analyses that are in use in our labs.

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Adaptations in the anterior cingulate cortex (ACC) have been implicated in alcohol and drug addiction. To identify genes that may contribute to excessive drinking, here we performed microarray analyses in laser microdissected rat ACC after a single or repeated administration of an intoxicating dose of alcohol (3 g/kg). Expression of the small G protein K-ras was differentially regulated following both single and repeated alcohol administration.

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