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Gut Microbiota‐Derived Extracellular Vesicles Influence Alcohol Intake Preferences in Rats
(Wiley, 2025-03)
Macarena Díaz‐Ubilla
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Aliosha I. Figueroa‐Valdés
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Hugo E. Tobar
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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> < 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>
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Connexin46 in the nucleus of cancer cells: a possible role as transcription modulator
(Springer Science and Business Media LLC, 2025-03-27)
Ainoa Fernández-Olivares
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Viviana P Orellana
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Jesús Llanquinao
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NUÑEZ VASQUEZ, GONZALO ESTEBAN
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Pablo Pérez-Moreno
Scopus© Citations 1 10
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Paw Skin as a Translational Model for Investigating Fibrotic and Inflammatory Wound Healing Defects in Recessive Dystrophic Epidermolysis Bullosa
(MDPI AG, 2025-04-30)
DE GREGORIO CONCHA, CRISTIAN ALEJANDRO
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Giselle Ramos-Gonzalez
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Bernardo Morales-Catalán
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EZQUER, EDUARDO FERNANDO
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EZQUER, EDUARDO MARCELO
Recessive dystrophic epidermolysis bullosa (RDEB) is a severe genetic disease caused by COL7A1 mutations. It leads to skin fragility, chronic inflammation, and impaired wound healing. The condition often results in fibrotic scarring, pseudosyndactyly, and cutaneous squamous cell carcinoma (SCC). However, current animal models fail to fully replicate chronic RDEB wounds. In this study, we used Collagen VII-hypomorphic mice (Col7a1flNeo/flNeo) and created full-thickness wounds on their paw skin, an area prone to fibrosis due to mechanical stress. We analyzed the healing process using histology, immunofluorescence, and electron microscopy. The RDEB mice showed delayed wound closure, increased inflammation, and poor granulation tissue formation. At 30 days post-injury, we observed persistent fibrosis, with elevated levels of Collagen I, α-SMA+ myofibroblasts, and tenascin-C. These mice also had fewer intraepidermal nerve fibers, which may help explain the neuropathic pain associated with RDEB. Our model reproduces the main features of chronic RDEB wounds. It offers a useful tool for evaluating therapies aimed at reducing inflammation, fibrosis, and tumor risk in these patients.
Scopus© Citations 3 4
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Hosts and vectors of scrub typhus in Chile: epidemiological study and molecular analyses of Orientia infection in rodents and rodent-associated mites
(Springer Science and Business Media LLC, 2024-12-18)
Constanza Martínez-Valdebenito
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Gerardo Acosta-Jamett
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Rayitray Abello
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Ju Jiang
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Allen L. Richards
<jats:title>Abstract</jats:title><jats:p><jats:italic>Candidatus</jats:italic> Orientia chiloensis causes scrub typhus over a wide geographical range in southern Chile. The life cycle, including vectors and reservoirs of this novel rickettsial pathogen, is incompletely understood. We analyzed rodent tissue and rodent-associated mite samples collected during a field study in six localities on Chiloé Island, where human scrub typhus cases have occurred. Using molecular methods, we detected <jats:italic>Orientia</jats:italic> DNA in 24.8% of rodents, belonging to five of seven captured species. <jats:italic>Orientia</jats:italic>-infection rates showed geographical variations, but were not influenced by rodent species, sex, age, and mite infestation. Phylogenetic analysis showed that <jats:italic>Orientia</jats:italic> sequences from trombiculid mites (<jats:italic>Proschoengastia eloisae</jats:italic>) were identical to those from scrub typhus patients from the same region. The results suggest that these rodent-associated mites serve as vectors and play an important role in the ecology of scrub typhus in southern Chile. Further studies are required to determine whether <jats:italic>Orientia</jats:italic>-infected rodents can also serve as reservoir of <jats:italic>Orientia</jats:italic> in Chile.</jats:p> <jats:p><jats:bold>Graphical Abstract</jats:bold></jats:p>
1Scopus© Citations 8
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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
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Paola Morales
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Daniela Santapau
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Javiera Gallardo
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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
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Prostaglandin E2 Exposure Disrupts E-Cadherin/Caveolin-1-Mediated Tumor Suppression to Favor Caveolin-1-Enhanced Migration, Invasion, and Metastasis in Melanoma Models
(2023)
Lorena Lobos-González
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Lorena Oróstica
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Natalia Díaz-Valdivia
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Victoria Rojas-Celis
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America Campos
<jats:p>Caveolin-1 (CAV1) is a membrane-bound protein that suppresses tumor development yet also promotes metastasis. E-cadherin is important in CAV1-dependent tumor suppression and prevents CAV1-enhanced lung metastasis. Here, we used murine B16F10 and human A375 melanoma cells with low levels of endogenous CAV1 and E-cadherin to unravel how co-expression of E-cadherin modulates CAV1 function in vitro and in vivo in WT C57BL/6 or Rag−/− immunodeficient mice and how a pro-inflammatory environment generated by treating cells with prostaglandin E2 (PGE2) alters CAV1 function in the presence of E-cadherin. CAV1 expression augmented migration, invasion, and metastasis of melanoma cells, and these effects were abolished via transient co-expression of E-cadherin. Importantly, exposure of cells to PGE2 reverted the effects of E-cadherin expression and increased CAV1 phosphorylation on tyrosine-14 and metastasis. Moreover, PGE2 administration blocked the ability of the CAV1/E-cadherin complex to prevent tumor formation. Therefore, our results support the notion that PGE2 can override the tumor suppressor potential of the E-cadherin/CAV1 complex and that CAV1 released from the complex is phosphorylated on tyrosine-14 and promotes migration/invasion/metastasis. These observations provide direct evidence showing how a pro-inflammatory environment caused here via PGE2 administration can convert a potent tumor suppressor complex into a promoter of malignant cell behavior.</jats:p>
1Scopus© Citations 5
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Transgenerational transmission of reproductive and metabolic dysfunction in the male progeny of polycystic ovary syndrome
(2023)
Sanjiv Risal
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Congru Li
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Qing Luo
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Romina Fornes
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Haojiang Lu
Scopus© Citations 11 3
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Helicobacter pylori outer membrane vesicles induce astrocyte reactivity through nuclear factor-κappa B activation and cause neuronal damage in vivo in a murine model
(2023)
Esteban Palacios
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Lorena Lobos-González
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Simón Guerrero
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Marcelo J. Kogan
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Baohai Shao
<jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p><jats:italic>Helicobacter pylori (Hp)</jats:italic> infects the stomach of 50% of the world’s population. Importantly, chronic infection by this bacterium correlates with the appearance of several extra-gastric pathologies, including neurodegenerative diseases. In such conditions, brain astrocytes become reactive and neurotoxic. However, it is still unclear whether this highly prevalent bacterium or the nanosized outer membrane vesicles (OMVs) they produce, can reach the brain, thus affecting neurons/astrocytes. Here, we evaluated the effects of <jats:italic>Hp</jats:italic> OMVs on astrocytes and neurons in vivo and in vitro.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>Purified OMVs were characterized by mass spectrometry (MS/MS). Labeled OMVs were administered orally or injected into the mouse tail vein to study OMV-brain distribution. By immunofluorescence of tissue samples, we evaluated: GFAP (astrocytes), βIII tubulin (neurons), and urease (OMVs). The in vitro effect of OMVs in astrocytes was assessed by monitoring NF-κB activation, expression of reactivity markers, cytokines in astrocyte-conditioned medium (ACM), and neuronal cell viability.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>Urease and GroEL were prominent proteins in OMVs. Urease (OMVs) was present in the mouse brain and its detection coincided with astrocyte reactivity and neuronal damage. In vitro, OMVs induced astrocyte reactivity by increasing the intermediate filament proteins GFAP and vimentin, the plasma membrane α<jats:sub>V</jats:sub>β<jats:sub>3</jats:sub> integrin, and the hemichannel connexin 43. OMVs also produced neurotoxic factors and promoted the release of IFNγ in a manner dependent on the activation of the transcription factor NF-κB. Surface antigens on reactive astrocytes, as well as secreted factors in response to OMVs, were shown to inhibit neurite outgrowth and damage neurons.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>OMVs administered orally or injected into the mouse bloodstream reach the brain, altering astrocyte function and promoting neuronal damage in vivo. The effects of OMVs on astrocytes were confirmed in vitro and shown to be NF-κB-dependent. These findings suggest that <jats:italic>Hp</jats:italic> could trigger systemic effects by releasing nanosized vesicles that cross epithelial barriers and access the CNS, thus altering brain cells.</jats:p> </jats:sec>
Scopus© Citations 36 2
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Effects of a High-Fat Diet and Docosahexaenoic Acid during Pregnancy on Fatty Acid Composition in the Fetal Livers of Mice
(2023)
Daniela Álvarez
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Macarena Ortiz
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Gabriel Valdebenito
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Nicolás Crisosto
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Bárbara Echiburú
<jats:p>A high-fat diet (HFD) during pregnancy promotes fat accumulation and reduces docosahexaenoic acid (DHA) levels in the liver of the offspring at postnatal ages, which can depend on fetal sex. However, the prenatal mechanisms behind these associations are still unclear. Thus, we analyzed if an HFD alters DHA content and the expression of molecules related to fatty acid (FA) metabolism in the fetal liver. Female C57BL/6 mice were fed a control diet or HFD for 4–6 weeks before pregnancy until the gestational day (GD) 17.5. A subgroup of each diet received DHA (100 mg/Kg) orally from GD 6.5 until 16.5. On GD 17.5, maternal livers, placentas, and livers from male and female fetuses were collected for FA profiling with gas-chromatography and gene expression of molecules related to FA metabolism using qPCR. PPAR-α protein expression was evaluated using Western blot. The gene expression of placental FA transporters was also assessed. An HFD increased eicosapentaenoic acid (EPA) and decreased DHA levels and protein expression of PPAR-α in the fetal livers of both sexes. DHA increased the gene expression of Ppara, Cpt1, and Acsl1 in the livers of female fetuses. Therefore, an HFD reduces DHA levels and PPAR-α, a master regulator of gene expression, in the fetal liver. In turn, the livers of female fetuses seem to be more sensitive to DHA action.</jats:p>
Scopus© Citations 2
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Chronic Voluntary Morphine Intake Is Associated with Changes in Brain Structures Involved in Drug Dependence in a Rat Model of Polydrug Use
(2023)
María Elena Quintanilla
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Paola Morales
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Daniela Santapau
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Alba Ávila
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Carolina Ponce
<jats:p>Chronic opioid intake leads to several brain changes involved in the development of dependence, whereby an early hedonistic effect (liking) extends to the need to self-administer the drug (wanting), the latter being mostly a prefrontal–striatal function. The development of animal models for voluntary oral opioid intake represents an important tool for identifying the cellular and molecular alterations induced by chronic opioid use. Studies mainly in humans have shown that polydrug use and drug dependence are shared across various substances. We hypothesize that an animal bred for its alcohol preference would develop opioid dependence and further that this would be associated with the overt cortical abnormalities clinically described for opioid addicts. We show that Wistar-derived outbred UChB rats selected for their high alcohol preference additionally develop: (i) a preference for oral ingestion of morphine over water, resulting in morphine intake of 15 mg/kg/day; (ii) marked opioid dependence, as evidenced by the generation of strong withdrawal signs upon naloxone administration; (iii) prefrontal cortex alterations known to be associated with the loss of control over drug intake, namely, demyelination, axonal degeneration, and a reduction in glutamate transporter GLT-1 levels; and (iv) glial striatal neuroinflammation and brain oxidative stress, as previously reported for chronic alcohol and chronic nicotine use. These findings underline the relevance of polydrug animal models and their potential in the study of the wide spectrum of brain alterations induced by chronic morphine intake. This study should be valuable for future evaluations of therapeutic approaches for this devastating condition.</jats:p>
7Scopus© Citations 6

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