Project Title
Development of novel therapeutic alternatives for alcohol-use disorders: a multidisciplinary approach
Partner Organisations
Internal ID
ACT210012
Principal Investigator
Eduardo Karahanian Vartevanian
Start Date
2021

Filters

Settings

Now showing 1 - 10 of 18
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Gut Microbiota‐Derived Extracellular Vesicles Influence Alcohol Intake Preferences in Rats
    (Wiley, 2025-03)
    Macarena Díaz‐Ubilla
    ;
    Aliosha I. Figueroa‐Valdés
    ;
    Hugo E. Tobar
    ;
    María Elena Quintanilla
    ;
    Eugenio Díaz
    <jats:title>ABSTRACT</jats:title><jats:p>Growing preclinical and clinical evidence suggests a link between gut microbiota dysbiosis and problematic alcohol consumption. Extracellular vesicles (EVs) are key mediators involved in bacteria‐to‐host communication. However, their potential role in mediating addictive behaviour remains unexplored. This study investigates the role of gut microbiota‐derived bacterial extracellular vesicles (bEVs) in driving high alcohol consumption. bEVs were isolated from the gut microbiota of a high alcohol‐drinking rat strain (UChB rats), either ethanol‐naïve or following chronic alcohol consumption and administered intraperitoneally or orally to alcohol‐rejecting male and female Wistar rats. Both types of UChB‐derived bEVs increased Wistar's voluntary alcohol consumption (three bottle choice test) up to 10‐fold (<jats:italic>p</jats:italic> &lt; 0.0001), indicating that bEVs are able and sufficient to transmit drinking behaviour across different rat strains. Molecular analysis revealed that bEVs administration did not induce systemic or brain inflammation in the recipient animals, suggesting that the increased alcohol intake triggered by UChB‐derived bEVs operates through an inflammation‐independent mechanism. Furthermore, we demonstrate that the vagus nerve mediates the bEV‐induced increase in alcohol consumption, as bilateral vagotomy completely abolished the high drinking behaviour induced by both intraperitoneally injected and orally administered bEVs. Thus, this study identifies bEVs as a novel mechanism underlying gut microbiota‐induced high alcohol intake in a vagus nerve‐dependent manner.</jats:p>
      7
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
      2Scopus© Citations 24
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
      2Scopus© Citations 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Morphine self-administration is inhibited by the antioxidant N‐acetylcysteine and the anti-inflammatory ibudilast; an effect enhanced by their co-administration
    (2024)
    María Elena Quintanilla
    ;
    Paola Morales
    ;
    Daniela Santapau
    ;
    Javiera Gallardo
    ;
    Rocío Rebolledo
    <jats:sec id="sec001"> <jats:title>Background</jats:title> <jats:p>The treatment of opioid addiction mainly involves the medical administration of methadone or other opioids, aimed at gradually reducing dependence and, consequently, the need for illicit opioid procurement. Thus, initiating opioid maintenance therapy with a lower level of dependence would be advantageous. There is compelling evidence indicating that opioids induce brain oxidative stress and associated glial activation, resulting in the dysregulation of glutamatergic homeostasis, which perpetuates drug intake. The present study aimed to determine whether inhibiting oxidative stress and/or neuroinflammation reduces morphine self-administration in an animal model of opioid dependence.</jats:p> </jats:sec> <jats:sec id="sec002"> <jats:title>Methods</jats:title> <jats:p>Morphine dependence, assessed as voluntary morphine self-administration, was evaluated in Wistar-derived UChB rats. Following an extended period of morphine self-administration, animals were administered either the antioxidant N-acetylcysteine (NAC; 40 mg/kg/day), the anti-inflammatory ibudilast (7.5 mg/kg/day) or the combination of both agents. Oxidative stress and neuroinflammation were evaluated in the hippocampus, a region involved in drug recall that feeds into the nucleus accumbens, where the levels of the glutamate transporters GLT-1 and xCT were further assessed.</jats:p> </jats:sec> <jats:sec id="sec003"> <jats:title>Results</jats:title> <jats:p>Daily administration of either NAC or ibudilast led to a mild reduction in voluntary morphine intake, while the co-administration of both therapeutic agents resulted in a marked inhibition (-57%) of morphine self-administration. The administration of NAC or ibudilast markedly reduced both the oxidative stress induced by chronic morphine intake and the activation of microglia and astrocytes in the hippocampus. However, only the combined administration of NAC + ibudilast was able to restore the normal levels of the glutamate transporter GLT-1 in the nucleus accumbens.</jats:p> </jats:sec> <jats:sec id="sec004"> <jats:title>Conclusion</jats:title> <jats:p>Separate or joint administration of an antioxidant and anti-inflammatory agent reduced voluntary opioid intake, which could have translational value for the treatment of opioid use disorders, particularly in settings where the continued maintenance of oral opioids is a therapeutic option.</jats:p> </jats:sec>
      1Scopus© Citations 3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Scopus© Citations 2  3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Extracellular Cysteines Are Critical to Form Functional Cx46 Hemichannels
    (2022)
    Ainoa Fernández-Olivares
    ;
    Eduardo Durán-Jara
    ;
    Daniel A. Verdugo
    ;
    Mariana C. Fiori
    ;
    Guillermo A. Altenberg
    <jats:p>Connexin (Cxs) hemichannels participate in several physiological and pathological processes, but the molecular mechanisms that control their gating remain elusive. We aimed at determining the role of extracellular cysteines (Cys) in the gating and function of Cx46 hemichannels. We studied Cx46 and mutated all of its extracellular Cys to alanine (Ala) (one at a time) and studied the effects of the Cys mutations on Cx46 expression, localization, and hemichannel activity. Wild-type Cx46 and Cys mutants were expressed at comparable levels, with similar cellular localization. However, functional experiments showed that hemichannels formed by the Cys mutants did not open either in response to membrane depolarization or removal of extracellular divalent cations. Molecular-dynamics simulations showed that Cys mutants may show a possible alteration in the electrostatic potential of the hemichannel pore and an altered disposition of important residues that could contribute to the selectivity and voltage dependency in the hemichannels. Replacement of extracellular Cys resulted in “permanently closed hemichannels”, which is congruent with the inhibition of the Cx46 hemichannel by lipid peroxides, through the oxidation of extracellular Cys. These results point to the modification of extracellular Cys as potential targets for the treatment of Cx46-hemichannel associated pathologies, such as cataracts and cancer, and may shed light into the gating mechanisms of other Cx hemichannels.</jats:p>
      2Scopus© Citations 6
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Genomic modifiers of neurological resilience in a Niemann‐Pick C family
    (Wiley, 2025-06-12)
    Macarena Las Heras
    ;
    Benjamín Szenfeld
    ;
    Valeria Olguín
    ;
    Juan Carlos Rubilar
    ;
    CALDERON GIADROSIC, JUAN FRANCISCO  
    Niemann-Pick type C (NPC) disease, caused by NPC1 or NPC2 variants, disrupts cholesterol and glycolipid trafficking, leading to diverse clinical manifestations. To understand the genetic basis of neurological resilience, we analyzed an NPC family with variable phenotypes, identifying loss-of-function variants in CCDC115, SLC4A5, DEPDC5, ETFDH, SNRNP200, and DOCK1 that co-segregated with milder neurological involvement. Using yeast models, we successfully predicted NPC-like severity based on orthologous gene variants. RNA-seq revealed a positive correlation between mitochondrial transcripts and cellular fitness. Modeling NPC in yeast lacking the SLC4A5 ortholog, bor1, enhanced cellular fitness, improved mitochondrial function, and reduced sterol accumulation. Our findings identify potential modifiers and biomarkers of NPC severity, highlighting mitochondrial pathways and SLC4A5 as a therapeutic target.
      6Scopus© Citations 3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
      3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    A Mouse Systems Genetics Approach Reveals Common and Uncommon Genetic Modifiers of Hepatic Lysosomal Enzyme Activities and Glycosphingolipids
    (2023)
    Anyelo Durán
    ;
    David A. Priestman
    ;
    Macarena Las Las Heras
    ;
    Boris Rebolledo-Jaramillo
    ;
    Valeria Olguín
    <jats:p>Identification of genetic modulators of lysosomal enzyme activities and glycosphingolipids (GSLs) may facilitate the development of therapeutics for diseases in which they participate, including Lysosomal Storage Disorders (LSDs). To this end, we used a systems genetics approach: we measured 11 hepatic lysosomal enzymes and many of their natural substrates (GSLs), followed by modifier gene mapping by GWAS and transcriptomics associations in a panel of inbred strains. Unexpectedly, most GSLs showed no association between their levels and the enzyme activity that catabolizes them. Genomic mapping identified 30 shared predicted modifier genes between the enzymes and GSLs, which are clustered in three pathways and are associated with other diseases. Surprisingly, they are regulated by ten common transcription factors, and their majority by miRNA-340p. In conclusion, we have identified novel regulators of GSL metabolism, which may serve as therapeutic targets for LSDs and may suggest the involvement of GSL metabolism in other pathologies.</jats:p>
      1Scopus© Citations 3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    A Novel Morphine Drinking Model of Opioid Dependence in Rats
    (2022)
    BERRIOS CARCAMO, PABLO ANDRES  
    ;
    Mauricio Quezada
    ;
    Daniela Santapau
    ;
    Paola Morales
    ;
    OLIVARES, MARIA BELEN  
    <jats:p>An animal model of voluntary oral morphine consumption would allow for a pre-clinical evaluation of new treatments aimed at reducing opioid intake in humans. However, the main limitation of oral morphine consumption in rodents is its bitter taste, which is strongly aversive. Taste aversion is often overcome by the use of adulterants, such as sweeteners, to conceal morphine taste or bitterants in the alternative bottle to equalize aversion. However, the adulterants’ presence is the cause for consumption choice and, upon removal, the preference for morphine is not preserved. Thus, current animal models are not suitable to study treatments aimed at reducing consumption elicited by morphine itself. Since taste preference is a learned behavior, just-weaned rats were trained to accept a bitter taste, adding the bitterant quinine to their drinking water for one week. The latter was followed by allowing the choice of quinine or morphine (0.15 mg/mL) solutions for two weeks. Then, quinine was removed, and the preference for morphine against water was evaluated. Using this paradigm, we show that rats highly preferred the consumption of morphine over water, reaching a voluntary morphine intake of 15 mg/kg/day. Morphine consumption led to significant analgesia and hyperlocomotion, and to a marked deprivation syndrome following the administration of the opioid antagonist naloxone. Voluntary morphine consumption was also shown to generate brain oxidative stress and neuroinflammation, signs associated with opioid dependence development. We present a robust two-bottle choice animal model of oral morphine self-administration for the evaluation of therapeutic interventions for the treatment of morphine dependence.</jats:p>
      1Scopus© Citations 18