CRIS

Permanent URI for this communityhttps://investigadores.udd.cl/handle/123456789/1

Browse

Search Results

Now showing 1 - 7 of 7

Some of the metrics are blocked by your
consent settings
Acute activation of hemichannels by ethanol leads to Ca2+-dependent gliotransmitter release in astrocytes
(2024)
Gonzalo I. Gómez
;
Claudia García-Rodríguez
;
Jesús E. Marillán
;
Sergio A. Vergara
;
Tanhia F. Alvear
<jats:p>Multiple studies have demonstrated that acute ethanol consumption alters brain function and cognition. Nevertheless, the mechanisms underlying this phenomenon remain poorly understood. Astrocyte-mediated gliotransmission is crucial for hippocampal plasticity, and recently, the opening of hemichannels has been found to play a relevant role in this process. Hemichannels are plasma membrane channels composed of six connexins or seven pannexins, respectively, that oligomerize around a central pore. They serve as ionic and molecular exchange conduits between the cytoplasm and extracellular milieu, allowing the release of various paracrine substances, such as ATP, D-serine, and glutamate, and the entry of ions and other substances, such as Ca<jats:sup>2+</jats:sup> and glucose. The persistent and exacerbated opening of hemichannels has been associated with the pathogenesis and progression of several brain diseases for at least three mechanisms. The uncontrolled activity of these channels could favor the collapse of ionic gradients and osmotic balance, the release of toxic levels of ATP or glutamate, cell swelling and plasma membrane breakdown and intracellular Ca<jats:sup>2+</jats:sup> overload. Here, we evaluated whether acute ethanol exposure affects the activity of astrocyte hemichannels and the possible repercussions of this phenomenon on cytoplasmatic Ca<jats:sup>2+</jats:sup> signaling and gliotransmitter release. Acute ethanol exposure triggered the rapid activation of connexin43 and pannexin1 hemichannels in astrocytes, as measured by time-lapse recordings of ethidium uptake. This heightened activity derived from a rapid rise in [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> linked to extracellular Ca<jats:sup>2+</jats:sup> influx and IP<jats:sub>3</jats:sub>-evoked Ca<jats:sup>2+</jats:sup> release from intracellular Ca<jats:sup>2+</jats:sup> stores. Relevantly, the acute ethanol-induced activation of hemichannels contributed to a persistent secondary increase in [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub>. The [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub>-dependent activation of hemichannels elicited by ethanol caused the increased release of ATP and glutamate in astroglial cultures and brain slices. Our findings offer fresh perspectives on the potential mechanisms behind acute alcohol-induced brain abnormalities and propose targeting connexin43 and pannexin1 hemichannels in astrocytes as a promising avenue to prevent deleterious consequences of alcohol consumption.</jats:p>
11Scopus© Citations 4
Some of the metrics are blocked by your
consent settings
SARS-CoV-2 spike protein S1 activates Cx43 hemichannels and disturbs intracellular Ca2+ dynamics
(2023)
Juan Prieto-Villalobos
;
Claudia M. Lucero
;
Maximiliano Rovegno
;
Gonzalo I. Gómez
;
Mauricio A. Retamal
<jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p>Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the ongoing coronavirus disease 2019 (COVID-19). An aspect of high uncertainty is whether the SARS-CoV-2 per se or the systemic inflammation induced by viral infection directly affects cellular function and survival in different tissues. It has been postulated that tissue dysfunction and damage observed in COVID-19 patients may rely on the direct effects of SARS-CoV-2 viral proteins. Previous evidence indicates that the human immunodeficiency virus and its envelope protein gp120 increase the activity of connexin 43 (Cx43) hemichannels with negative repercussions for cellular function and survival. Here, we evaluated whether the spike protein S1 of SARS-CoV-2 could impact the activity of Cx43 hemichannels.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>We found that spike S1 time and dose-dependently increased the activity of Cx43 hemichannels in HeLa-Cx43 cells, as measured by dye uptake experiments. These responses were potentiated when the angiotensin-converting enzyme 2 (ACE2) was expressed in HeLa-Cx43 cells. Patch clamp experiments revealed that spike S1 increased unitary current events with conductances compatible with Cx43 hemichannels. In addition, Cx43 hemichannel opening evoked by spike S1 triggered the release of ATP and increased the [Ca<jats:sup>2+</jats:sup>]<jats:sub>i</jats:sub> dynamics elicited by ATP.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>We hypothesize that Cx43 hemichannels could represent potential pharmacological targets for developing therapies to counteract SARS-CoV-2 infection and their long-term consequences.</jats:p> </jats:sec>
6Scopus© Citations 7
Some of the metrics are blocked by your
consent settings
Hypertensive Nephropathy: Unveiling the Possible Involvement of Hemichannels and Pannexons
(2022)
Claudia M. Lucero
;
Juan Prieto-Villalobos
;
Lucas Marambio-Ruiz
;
Javiera Balmazabal
;
Tanhia F. Alvear
<jats:p>Hypertension is one of the most common risk factors for developing chronic cardiovascular diseases, including hypertensive nephropathy. Within the glomerulus, hypertension causes damage and activation of mesangial cells (MCs), eliciting the production of large amounts of vasoactive and proinflammatory agents. Accordingly, the activation of AT1 receptors by the vasoactive molecule angiotensin II (AngII) contributes to the pathogenesis of renal damage, which is mediated mostly by the dysfunction of intracellular Ca2+ ([Ca2+]i) signaling. Similarly, inflammation entails complex processes, where [Ca2+]i also play crucial roles. Deregulation of this second messenger increases cell damage and promotes fibrosis, reduces renal blood flow, and impairs the glomerular filtration barrier. In vertebrates, [Ca2+]i signaling depends, in part, on the activity of two families of large-pore channels: hemichannels and pannexons. Interestingly, the opening of these channels depends on [Ca2+]i signaling. In this review, we propose that the opening of channels formed by connexins and/or pannexins mediated by AngII induces the ATP release to the extracellular media, with the subsequent activation of purinergic receptors. This process could elicit Ca2+ overload and constitute a feed-forward mechanism, leading to kidney damage.</jats:p>
5Scopus© Citations 18
Some of the metrics are blocked by your
consent settings
Astroglial gliotransmitters released via Cx43 hemichannels regulate NMDAR‐dependent transmission and short‐term fear memory in the basolateral amygdala
(2022)
Sergio Linsambarth
;
Francisco J. Carvajal
;
Rodrigo Moraga‐Amaro
;
Luis Mendez
;
Giovanni Tamburini
Scopus© Citations 19 2
Some of the metrics are blocked by your
consent settings
Interferon-γ and high glucose-induced opening of Cx43 hemichannels causes endothelial cell dysfunction and damage
(2020)
Juan C. Sáez
;
Susana Contreras-Duarte
;
Valeria C. Labra
;
Cristian A. Santibañez
;
Luis A. Mellado
Scopus© Citations 30 2
Some of the metrics are blocked by your
consent settings
Connexin and Pannexin-Based Channels in Oligodendrocytes: Implications in Brain Health and Disease
(2019)
Sebastián Vejar
;
Juan E. Oyarzún
;
RETAMAL LUCERO, MAURICIO ANTONIO
;
Fernando C. Ortiz
;
Juan A. Orellana
7Scopus© Citations 28
Some of the metrics are blocked by your
consent settings
Role of Astroglial Hemichannels and Pannexons in Memory and Neurodegenerative Diseases
(2016)
Juan A. Orellana
;
RETAMAL LUCERO, MAURICIO ANTONIO
;
Rodrigo Moraga-Amaro
;
Jimmy Stehberg
20Scopus© Citations 40

CRIS

Browse

Filters

Settings

Sort By

Results per page

Search Results