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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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The role of astrocytes in depression, its prevention, and treatment by targeting astroglial gliotransmitter release
(2024)
Yorley Duarte
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Daisy Quintana-Donoso
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Rodrigo Moraga-Amaro
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Ivanka Dinamarca
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Yordan Lemunao
<jats:p>The role of ventral hippocampus (vHipp) astroglial gliotransmission in depression was studied using chronic restraint stress (CRS) and chronic unpredictable mild stress (CUMS) rodent models. CRS increased Cx43 hemichannel activity and extracellular glutamate levels in the vHipp and blocking astroglial Cx43 hemichannel-dependent gliotransmission during CRS prevented the development of depression and glutamate buildup. Moreover, the acute blockade of Cx43 hemichannels induced antidepressant effects in rats previously subjected to CRS or CUMS. This antidepressant effect was prevented by coinjection of glutamate and D-serine. Furthermore, Cx43 hemichannel blockade decreased postsynaptic NMDAR currents in vHipp slices in a glutamate and D-serine-dependent manner. Notably, chronic microinfusion of glutamate and D-serine, L-serine, or the NMDAR agonist NMDA, into the vHipp induced depressive-like symptoms in nonstressed rats. We also identified a small molecule, cacotheline, which blocks Cx43 hemichannels and its systemic administration induced rapid antidepressant effects, preventing stress-induced increases in astroglial Cx43 hemichannel activity and extracellular glutamate in the vHipp, without sedative or locomotor side effects. In conclusion, chronic stress increases Cx43 hemichannel-dependent release of glutamate and D-/L-serine from astrocytes in the vHipp, overactivating postsynaptic NMDARs and triggering depressive-like symptoms. This study highlights the critical role of astroglial gliotransmitter release in chronic stress-induced depression and suggests it can be used as a target for the prevention and treatment of depression.</jats:p>
Scopus© Citations 5 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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Evaluation of Eight Serological Tests for Diagnosis of Imported Schistosomiasis
(2012)
Hans-Friedemann Kinkel
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Sabine Dittrich
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Britta Bäumer
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WEITZEL, THOMAS
<jats:title>ABSTRACT</jats:title> <jats:p> The diagnosis of schistosomiasis in individuals from countries where the disease is not endemic is challenging, and few data are available on the accuracy of serological diagnosis in those patients. We evaluated the performance of eight serological assays, including four commercial kits, in the diagnosis of imported schistosomiasis in individuals from areas where the disease is not endemic, including six enzyme-linked immunosorbent assays using three different antigens, an indirect hemagglutination assay, and an indirect immunofluorescent-antibody test. To analyze the assays, we used a total of 141 serum samples, with 121 derived from patients with various parasitic infections (among which were 37 cases of schistosomiasis) and 20 taken from healthy volunteers. The sensitivity values for detection of schistosomiasis cases ranged from 41% to 78% and were higher for <jats:named-content content-type="genus-species">Schistosoma mansoni</jats:named-content> than for <jats:named-content content-type="genus-species">S. haematobium</jats:named-content> infections. Specificity values ranged from 76% to 100%; false-positive results were most frequent for samples from patients with cestode infections. By combining two or more tests, sensitivity improved markedly and specificity decreased only moderately. Serological tests are useful instruments for diagnosing imported schistosomiasis in countries where the disease is not endemic, but due to limitations in test sensitivities, we recommend the use of two or more assays in parallel. </jats:p>
Scopus© Citations 91
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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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Scrub typhus in Tierra del Fuego: a tropical rickettsiosis in a subantarctic region
(2021)
WEITZEL, THOMAS
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AYLWIN RAMIREZ, MABEL CRISTINA
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Constanza Martínez-Valdebenito
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Gerardo Acosta-Jamett
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Katia Abarca
10Scopus© Citations 10
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Generation and genetic repair of two human induced pluripotent cell lines from patients with Epidermolysis Bullosa simplex and dilated cardiomyopathy associated with a heterozygous mutation in the translation initiation codon of KLHL24
(2021)
Veronika Ramovs
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FUENTES BUSTOS, MARIA IGNACIA
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Christian Freund
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Harald Mikkers
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Christine L. Mummery
Scopus© Citations 9 1
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Lupus eritematoso sistémico buloso: Una manifestación infrecuente en población pediátrica
(2021)
María Trinidad Hasbún Z.
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ROLLAN MARZOLO, MARIA PAZ
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Ximena Chaparro R.
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Cecilia Fischer S.
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Adriana Castrillón V.
<jats:p>El lupus eritematoso sistémico buloso (LESB) es una enfermedad ampollar subepidérmica autoinmune secundaria a la presencia de autoanticuerpos contra el colágeno VII de la membrana basal. Es considerada una variante de lupus eritematoso sistémico (LES), siendo infrecuente en la población pediátrica.Objetivo: Describir caso de paciente pediátrica con erupción ampollar compatible con LESB.Caso Clínico: Paciente de sexo femenino de 16 años de ascendencia mapuche, con antecedentes de LES diagnosticado a los 10 años de edad, en tratamiento. Consultó por erupción vesiculobulosa generalizada de 6 semanas de evolución, sin sintomatología sistémica. Se realizó biopsia para estudio histológico e inmunofluorescencia directa (IFD), confirmándose el diagnóstico de LESB. La paciente respondió favorablemente al tratamiento con dapsona en dosis de 100 mg/día (asociado a su tratamiento de base), sin nuevas reactivaciones a 8 años de seguimiento.Conclusión: El LESB es una manifestación infrecuente de LES. Aunque la clínica es similar a la de otras dermatosis ampollares, la correlación entre la presencia de LES, los hallazgos histopatológicos y de IFD permiten confirmar el diagnóstico. Si bien se ha reportado mayor riesgo de LES en población de ascendencia indígena, faltan estudios respecto a la asociación de LESB en esta etnia.</jats:p>
Scopus© Citations 2 1
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Administration of Secretome Derived from Human Mesenchymal Stem Cells Induces Hepatoprotective Effects in Models of Idiosyncratic Drug-Induced Liver Injury Caused by Amiodarone or Tamoxifen
(2023)
HUANG, YA LIN
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Silva Villalobos, Verónica
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DE GREGORIO CONCHA, CRISTIAN ALEJANDRO
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Álvaro A. Elorza
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Patricio Léniz
<jats:p>Drug-induced liver injury (DILI) is one of the leading causes of acute liver injury. While many factors may contribute to the susceptibility to DILI, obese patients with hepatic steatosis are particularly prone to suffer DILI. The secretome derived from mesenchymal stem cell has been shown to have hepatoprotective effects in diverse in vitro and in vivo models. In this study, we evaluate whether MSC secretome could improve DILI mediated by amiodarone (AMI) or tamoxifen (TMX). Hepatic HepG2 and HepaRG cells were incubated with AMI or TMX, alone or with the secretome of MSCs obtained from human adipose tissue. These studies demonstrate that coincubation of AMI or TMX with MSC secretome increases cell viability, prevents the activation of apoptosis pathways, and stimulates the expression of priming phase genes, leading to higher proliferation rates. As proof of concept, in a C57BL/6 mouse model of hepatic steatosis and chronic exposure to AMI, the MSC secretome was administered endovenously. In this study, liver injury was significantly attenuated, with a decrease in cell infiltration and stimulation of the regenerative response. The present results indicate that MSC secretome administration has the potential to be an adjunctive cell-free therapy to prevent liver failure derived from DILI caused by TMX or AMI.</jats:p>
24Scopus© Citations 14

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