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Novel Pannexin-1-Coupled Signaling Cascade Involved in the Control of Endothelial Cell Function and NO-Dependent Relaxation
(2021)
Mauricio A. Lillo
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Pablo S. Gaete
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Mariela Puebla
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Pía C. Burboa
;
Inés Poblete
<jats:p>Deletion of pannexin-1 (Panx-1) leads not only to a reduction in endothelium-derived hyperpolarization but also to an increase in NO-mediated vasodilation. Therefore, we evaluated the participation of Panx-1-formed channels in the control of membrane potential and [Ca2+]i of endothelial cells. Changes in NO-mediated vasodilation, membrane potential, superoxide anion (O2⋅–) formation, and endothelial cell [Ca2+]i were analyzed in rat isolated mesenteric arterial beds and primary cultures of mesenteric endothelial cells. Inhibition of Panx-1 channels with probenecid (1 mM) or the Panx-1 blocking peptide 10Panx (60 μM) evoked an increase in the ACh (100 nM)-induced vasodilation of KCl-contracted mesenteries and in the phosphorylation level of endothelial NO synthase (eNOS) at serine 1177 (P-eNOSS1177) and Akt at serine 473 (P-AktS473). In addition, probenecid or 10Panx application activated a rapid, tetrodotoxin (TTX, 300 nM)-sensitive, membrane potential depolarization and [Ca2+]i increase in endothelial cells. Interestingly, the endothelial cell depolarization was converted into a transient spike after removing Ca2+ ions from the buffer solution and in the presence of 100 μM mibefradil or 10 μM Ni2+. As expected, Ni2+ also abolished the increment in [Ca2+]i. Expression of Nav1.2, Nav1.6, and Cav3.2 isoforms of voltage-dependent Na+ and Ca2+ channels was confirmed by immunocytochemistry. Furthermore, the Panx-1 channel blockade was associated with an increase in O2⋅– production. Treatment with 10 μM TEMPOL or 100 μM apocynin prevented the increase in O2⋅– formation, ACh-induced vasodilation, P-eNOSS1177, and P-AktS473 observed in response to Panx-1 inhibition. These findings indicate that the Panx-1 channel blockade triggers a novel complex signaling pathway initiated by the sequential activation of TTX-sensitive Nav channels and Cav3.2 channels, leading to an increase in NO-mediated vasodilation through a NADPH oxidase-dependent P-eNOSS1177, which suggests that Panx-1 may be involved in the endothelium-dependent control of arterial blood pressure.</jats:p>
7Scopus© Citations 16
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CRISPR/Cas13-Based Platforms for a Potential Next-Generation Diagnosis of Colorectal Cancer through Exosomes Micro-RNA Detection: A Review
(2021)
Benjamín Durán-Vinet
;
Karla Araya-Castro
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CALDERON GIADROSIC, JUAN FRANCISCO
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Luis Vergara
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Helga Weber
<jats:p>Colorectal cancer (CRC) is the third most prevalent cancer with the second highest mortality rate worldwide. CRC is a heterogenous disease with multiple risk factors associated, including obesity, smoking, and use of alcohol. Of total CRC cases, 60% are diagnosed in late stages, where survival can drop to about 10%. CRC screening programs are based primarily on colonoscopy, yet this approach is invasive and has low patient adherence. Therefore, there is a strong incentive for developing molecular-based methods that are minimally invasive and have higher patient adherence. Recent reports have highlighted the importance of extracellular vesicles (EVs), specifically exosomes, as intercellular communication vehicles with a broad cargo, including micro-RNAs (miRNAs). These have been syndicated as robust candidates for diagnosis, primarily for their known activities in cancer cells, including immunoevasion, tumor progression, and angiogenesis, whereas miRNAs are dysregulated by cancer cells and delivered by cancer-derived exosomes (CEx). Quantitative polymerase chain reaction (qPCR) has shown good results detecting specific cancer-derived exosome micro-RNAs (CEx-miRNAs) associated with CRC, but qPCR also has several challenges, including portability and sensitivity/specificity issues regarding experiment design and sample quality. CRISPR/Cas-based platforms have been presented as cost-effective, ultrasensitive, specific, and robust clinical detection tools in the presence of potential inhibitors and capable of delivering quantitative and qualitative real-time data for enhanced decision-making to healthcare teams. Thereby, CRISPR/Cas13-based technologies have become a potential strategy for early CRC diagnosis detecting CEx-miRNAs. Moreover, CRISPR/Cas13-based platforms’ ease of use, scalability, and portability also showcase them as a potential point-of-care (POC) technology for CRC early diagnosis. This study presents two potential CRISPR/Cas13-based methodologies with a proposed panel consisting of four CEx-miRNAs, including miR-126, miR-1290, miR-23a, and miR-940, to streamline novel applications which may deliver a potential early diagnosis and prognosis of CRC.</jats:p>
7Scopus© Citations 22
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Isolation of Ciprofloxacin and Ceftazidime-Resistant Enterobacterales From Vegetables and River Water Is Strongly Associated With the Season and the Sample Type
(2021)
Constanza Díaz-Gavidia
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Carla Barría
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RIVAS JIMENEZ, LINA MARIA
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Patricia García
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Francisca P. Alvarez
<jats:p>The dissemination of antibiotic-resistant bacteria (ARB) from water used for crop irrigation to vegetables is poorly studied. During a year, five farmer markets in a city in Central Chile were visited, and 478 vegetable samples (parsleys, corianders, celeries, lettuces, chards, and beets) were collected. Simultaneously, 32 water samples were collected from two rivers which are used to irrigate the vegetables produced in the area. Resistant Enterobacterales were isolated and identified. Colistin resistance gene <jats:italic>mcr-1</jats:italic> and extended spectrum β-lactamases (ESBL) were molecularly detected. The association of environmental factors was evaluated, with the outcomes being the presence of Enterobacterales resistant to four antibiotic families and the presence of multidrug resistance (MDR) phenotypes. Parsley, coriander, and celery showed the highest prevalence of resistant Enterobacterales (41.9% for ciprofloxacin and 18.5% for ceftazidime). A total of 155 isolates were obtained, including <jats:italic>Escherichia coli</jats:italic> (<jats:italic>n</jats:italic>=109), <jats:italic>Citrobacter</jats:italic> sp. (<jats:italic>n</jats:italic>=20), <jats:italic>Enterobacter cloacae</jats:italic> complex (<jats:italic>n</jats:italic>=8), <jats:italic>Klebsiella pneumoniae</jats:italic> (<jats:italic>n</jats:italic>=8), and <jats:italic>Klebsiella aerogenes</jats:italic> (<jats:italic>n</jats:italic>=1). Resistance to ampicillin (63.2%) and ciprofloxacin (74.2%) was most frequently found; 34.5% of the isolates showed resistance to third-generation cephalosporins, and the MDR phenotype represented 51.6% of the isolates. In two <jats:italic>E. coli</jats:italic> isolates (1.29%), the gene <jats:italic>mcr-1</jats:italic> was found and ESBL genes were found in 23/62 isolates (37%), with <jats:italic>bla</jats:italic><jats:sub>CTX-M</jats:sub> being the most frequently found in 20 isolates (32%). Resistant Enterobacterales isolated during the rainy season were less likely to be MDR as compared to the dry season. Understanding environmental associations represent the first step toward an improved understanding of the public health impact of ARB in vegetables and water.</jats:p>
1Scopus© Citations 28
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Higher Prevalence of Extended-Spectrum Cephalosporin-Resistant Enterobacterales in Dogs Attended for Enteric Viruses in Brazil Before and After Treatment with Cephalosporins
(2021)
Marília Salgado-Caxito
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Andrea I. Moreno-Switt
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Antonio Carlos Paes
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Carlos Shiva
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MUNITA SEPULVEDA, JOSE MANUEL
<jats:p>The extensive use of antibiotics is a leading cause for the emergence and spread of antimicrobial resistance (AMR) among dogs. However, the impact of using antibiotics to treat viral infections on AMR remains unknown. In this study, we compared the prevalence of extended-spectrum cephalosporin-resistant Enterobacterales (ESCR-E) between dogs with a suspected infection of canine parvovirus (CPV) and canine distemper (CDV) before and after treatment with third-generation cephalosporins. We found a higher prevalence of ESCR-E faecal carriage in dogs suspected of CPV (37%) and CDV (15%) compared to dogs with noninfectious pathologies (9%) even prior to the start of their treatment. A 7-day course of ceftriaxone or ceftiofur administrated to CPV and CDV-suspected dogs substantially increased their ESCR-E faecal carriage during treatment (85% for CPV and 57% for CDV), and 4 weeks after the treatment ended (89% for CPV and 60% for CDV) when dogs were back in their households. Most of the observed resistance was carried by ESCR-E. coli carrying blaCTX-M genes. Our results suggest the need to optimize prophylactic antibiotic therapy in dogs treated for a suspected viral infection to prevent ESCR-E emergence and spread in the community.</jats:p>
5Scopus© Citations 15
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Neonatal Mesenchymal Stem Cell Treatment Improves Myelination Impaired by Global Perinatal Asphyxia in Rats
(2021)
Andrea Tapia-Bustos
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Carolyne Lespay-Rebolledo
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Valentina Vío
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Ronald Pérez-Lobos
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Emmanuel Casanova-Ortiz
<jats:p>The effect of perinatal asphyxia (PA) on oligodendrocyte (OL), neuroinflammation, and cell viability was evaluated in telencephalon of rats at postnatal day (P)1, 7, and 14, a period characterized by a spur of neuronal networking, evaluating the effect of mesenchymal stem cell (MSCs)-treatment. The issue was investigated with a rat model of global PA, mimicking a clinical risk occurring under labor. PA was induced by immersing fetus-containing uterine horns into a water bath for 21 min (AS), using sibling-caesarean-delivered fetuses (CS) as controls. Two hours after delivery, AS and CS neonates were injected with either 5 μL of vehicle (10% plasma) or 5 × 104 MSCs into the lateral ventricle. Samples were assayed for myelin-basic protein (MBP) levels; Olig-1/Olig-2 transcriptional factors; Gglial phenotype; neuroinflammation, and delayed cell death. The main effects were observed at P7, including: (i) A decrease of MBP-immunoreactivity in external capsule, corpus callosum, cingulum, but not in fimbriae of hippocampus; (ii) an increase of Olig-1-mRNA levels; (iii) an increase of IL-6-mRNA, but not in protein levels; (iv) an increase in cell death, including OLs; and (v) MSCs treatment prevented the effect of PA on myelination, OLs number, and cell death. The present findings show that PA induces regional- and developmental-dependent changes on myelination and OLs maturation. Neonatal MSCs treatment improves survival of mature OLs and myelination in telencephalic white matter.</jats:p>
Scopus© Citations 7 2
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miRNA Landscape in Pathogenesis and Treatment of Vogt–Koyanagi–Harada Disease
(2021)
Fabian Vega-Tapia
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Mario Bustamante
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Rodrigo A. Valenzuela
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Cristhian A. Urzua
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Loreto Cuitino
<jats:p>miRNAs, one of the members of the noncoding RNA family, are regulators of gene expression in inflammatory and autoimmune diseases. Changes in miRNA pool expression have been associated with differentiation of CD4<jats:sup>+</jats:sup> T cells toward an inflammatory phenotype and with loss of self-tolerance in autoimmune diseases. Vogt–Koyanagi–Harada (VKH) disease is a chronic multisystemic pathology, affecting the uvea, inner ear, central nervous system, and skin. Several lines of evidence support an autoimmune etiology for VKH, with loss of tolerance against retinal pigmented epithelium-related self-antigens. This deleterious reaction is characterized by exacerbated inflammation, due to an aberrant T<jats:sub><jats:italic>H</jats:italic></jats:sub>1 and T<jats:sub><jats:italic>H</jats:italic></jats:sub>17 polarization and secretion of their proinflammatory hallmark cytokines interleukin 6 (IL-6), IL-17, interferon γ, and tumor necrosis factor α, and an impaired CD4<jats:sup>+</jats:sup> CD25<jats:sup><jats:italic>high</jats:italic></jats:sup> FoxP3<jats:sup>+</jats:sup> regulatory T cell function. To restrain inflammation, VKH is pharmacologically treated with corticosteroids and immunosuppressive drugs as first and second line of therapy, respectively. Changes in the expression of miRNAs related to immunoregulatory pathways have been associated with VKH development, whereas some genetic variants of miRNAs have been found to be risk modifiers of VKH. Furthermore, the drugs commonly used in VKH treatment have great influence on miRNA expression, including those miRNAs associated to VKH disease. This relationship between response to therapy and miRNA regulation suggests that these small noncoding molecules might be therapeutic targets for the development of more effective and specific pharmacological therapy for VKH. In this review, we discuss the latest evidence regarding regulation and alteration of miRNA associated with VKH disease and its treatment.</jats:p>
4Scopus© Citations 7
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Proteomic Analysis of Niemann-Pick Type C Hepatocytes Reveals Potential Therapeutic Targets for Liver Damage
(2021)
Elisa Balboa
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Tamara Marín
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Juan Esteban Oyarzún
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Pablo S. Contreras
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Robert Hardt
<jats:p>Niemann-Pick type C disease (NPCD) is a lysosomal storage disorder caused by mutations in the NPC1 gene. The most affected tissues are the central nervous system and liver, and while significant efforts have been made to understand its neurological component, the pathophysiology of the liver damage remains unclear. In this study, hepatocytes derived from wild type and Npc1−/− mice were analyzed by mass spectrometry (MS)-based proteomics in conjunction with bioinformatic analysis. We identified 3832 proteins: 416 proteins had a p-value smaller than 0.05, of which 37% (n = 155) were considered differentially expressed proteins (DEPs), 149 of them were considered upregulated, and 6 were considered downregulated. We focused the analysis on pathways related to NPC pathogenic mechanisms, finding that the most significant changes in expression levels occur in proteins that function in the pathways of liver damage, lipid metabolism, and inflammation. Moreover, in the group of DEPs, 30% (n = 47) were identified as lysosomal proteins and 7% (n = 10) were identified as mitochondrial proteins. Importantly, we found that lysosomal DEPs, including CTSB/D/Z, LIPA, DPP7 and GLMP, and mitocondrial DEPs, AKR1B10, and VAT1 had been connected with liver fibrosis, damage, and steatosis in previous studies, validiting our dataset. Our study found potential therapeutic targets for the treatment of liver damage in NPCD.</jats:p>
Scopus© Citations 9 1
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Seroprevalence of Natural and Acquired Immunity against the SARS-CoV-2 Virus in a Population Cohort from Two Chilean Cities, 2020–2022
(2023)
Loreto Núñez-Franz
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Muriel Ramírez-Santana
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RUBILAR RAMIREZ, PAOLA
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Macarena Said
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VIAL COX, MARIA CECILIA
<jats:p>Background: Chile has achieved the highest coverage for vaccines against the SARS-CoV-2 virus worldwide. Objective: To assess the progression of immunity (natural and acquired by vaccine) in a cohort from two Chilean cities. Methods: Individuals (n = 386) who participated in three phases of population-based serial prevalence studies were included (2020–2021 and 2022). Presence of SARS-CoV-2 antibodies was measured in serum. Data including time of vaccination and type of vaccine received were analysed with descriptive statistics. Results: Seroprevalence was 3.6% in the first round and increased to 96.9% in the second and 98.7% in the third. In the third round, 75% of individuals who had received the basal full scheme were seropositive at 180 days or more since their last dose; 98% of individuals who received one booster dose were seropositive at 180 days or more, and 100% participants who received two boosters were seropositive, regardless of time since their last dose. Participants receiving mRNA vaccines had higher seroprevalence rates over time. Conclusions: The high vaccination coverage in Chile enabled the population to maintain high levels of antibodies. Vaccination boosters are essential to maintain immunity over time, which also depends on the type of vaccine administered.</jats:p>
1Scopus© Citations 12
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Prácticas y preferencias alimentarias y de actividad física en niños y niñas: Una aproximación desde los Parlamentos Escolares en establecimientos educacionales
(2023)
Tito Pizarro
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Macarena Jara
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Daisy Margarit
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José Luis Palacios
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PINHEIRO FERNANDES, ANNA CHRISTINA
<jats:p>En Chile la malnutrición por exceso continúa en aumento, afectando especialmente a la población infantil. Solucionar esta problemática de salud pública requiere desarrollar estrategias de promoción y prevención que consideren las propuestas de las comunidades, especialmente la de los propios niños y niñas. Objetivo: Conocer las opiniones y sugerencias de niños y niñas de tercero y cuarto básico de escuelas de la zona sur de Santiago de Chile, respecto de sus prácticas alimentarias y de actividad física, en el marco del proyecto FONDEF IT 1810016. Sujetos y Método: Se desarrollaron siete parlamentos escolares en siete escuelas mediante una metodología cualitativa participativa, recogiendo las opiniones de 176 niños y niñas acerca de sus hábitos y preferencias tanto de alimentos como de actividad física. Resultados: Los alimentos más consumidos y preferidos son aquellos fáciles de preparar y de alta disponibilidad, como pan, tallarines y leche. Los alimentos que requieren preparación, como pescado, legumbres, frutas, verduras y preparaciones caseras, son menos consumidos y tienen menos preferencia. En las actividades físicas recreativas destacan los videojuegos y el fútbol. Los estudiantes proponen aumentar las horas de educación física, los recreos y mejorar la disponibilidad y acceso a alimentos saludables en los entornos escolares como estrategia de solución al problema de la malnutrición por exceso. Conclusiones: Los Parlamentos Escolares como estrategia participativa aportan en la generación conjunta de conocimiento. La necesidad de incluir a las comunidades como partes interesadas en las iniciativas de salud, reconoce a través de su participación, a los niños y las niñas como actores sujetos de derechos.</jats:p>
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Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. in Southern Chile
(2023)
María Carolina Silva de la Fuente
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Caricia Pérez
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Constanza Martínez-Valdebenito
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Pérez Ball, Ruth
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VIAL COX, MARIA CECILIA
<jats:sec id="sec001"> <jats:title>Background</jats:title> <jats:p>Scrub typhus is a potentially severe infection caused by bacteria of the genus <jats:italic>Orientia</jats:italic>, endemic in Asia-Pacific and recently discovered in southern Chile. The presented study aimed to determine the prevalence and species richness of rodent-associated trombiculid mites and their infection with <jats:italic>Orientia</jats:italic> spp. in different areas of two regions in southern Chile.</jats:p> </jats:sec> <jats:sec id="sec002"> <jats:title>Methodology/Principal findings</jats:title> <jats:p>During summer 2020, trombiculid mites were collected from rodents captured in three areas in southern Chile known to be endemic for scrub typhus (Cochamó and Chiloé Island in the Los Lagos Region and Tortel in the Aysén Region). A total of 132 rodents belonging to five species were captured using Sherman-like traps; 89.4% were infested with trombiculids. Mite specimens were morphologically identified and subsequently tested by <jats:italic>Orientia</jats:italic>-specific qPCR. Six mite species were identified. Among chigger-infested rodents, 33.9% carried <jats:italic>Orientia</jats:italic>-positive mites; this rate was higher in Tortel (63.8%) than in Cochamó (45.0%) and Chiloé Island (2.0%). The analysis of individual mites (n = 901) revealed that 31.2% of <jats:italic>Herpetacarus antarctica</jats:italic> samples (n = 202) were positive for <jats:italic>Orientia</jats:italic> DNA; the prevalence was 7.0% in <jats:italic>Paratrombicula neuquenensis</jats:italic> (n = 213), 6.9% in <jats:italic>Herpetacarus eloisae</jats:italic> (n = 144), 3.6% in <jats:italic>Argentinacarus expansus</jats:italic> (n = 55), and 0% in <jats:italic>Paratrombicula goffi</jats:italic> (n = 110) and <jats:italic>Quadraseta chiloensis</jats:italic> (n = 177). The southernmost site (Tortel) showed the highest rates of trombiculid infestation, trombiculid load, and <jats:italic>Orientia</jats:italic> infection in the captured rodents.</jats:p> </jats:sec> <jats:sec id="sec003"> <jats:title>Conclusions/Significance</jats:title> <jats:p>Our study provides new insights into the trombiculid fauna and prevalence of <jats:italic>Orientia</jats:italic> in mites collected from wild rodents in southern Chile. <jats:italic>Orientia</jats:italic> DNA was detected in four of the six mite species. Rates of infestation, mite loads, and <jats:italic>Orientia</jats:italic> prevalences differed geographically and were highest in the Aysén Region. Our data improve our knowledge on possible vectors of scrub typhus and their distribution in Chile.</jats:p> </jats:sec>
1Scopus© Citations 9 2

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