Met signaling in cardiomyocytes is required for normal cardiac function in adult mice

et al.Hepatocyte growth factor (HGF) and its receptor, Met, are key determinants of distinct developmental processes. Although HGF exerts cardio-protective effects in a number of cardiac pathologies, it remains unknown whether HGF/Met signaling is essential for myocardial development and/or physiological function in adulthood. We therefore investigated the requirement of HGF/Met signaling in cardiomyocyte for embryonic and postnatal heart development and function by conditional inactivation of the Met receptor in cardiomyocytes using the Cre-α-MHC mouse line (referred to as α-MHCMet-KO). Although α-MHCMet-KO mice showed normal heart development and were viable and fertile, by 6. months of age, males developed cardiomyocyte hypertrophy, associated with interstitial fibrosis. A significant upregulation in markers of myocardial damage, such as β-MHC and ANF, was also observed. By the age of 9. months, α-MHCMet-KO males displayed systolic cardiac dysfunction. Mechanistically, we provide evidence of a severe imbalance in the antioxidant defenses in α-MHCMet-KO hearts involving a reduced expression and activity of catalase and superoxide dismutase, with consequent reactive oxygen species accumulation. Similar anomalies were observed in females, although with a slower kinetics. We also found that Met signaling down-regulation leads to an increase in TGF-β production and a decrease in p38MAPK activation, which may contribute to phenotypic alterations displayed in α-MHCMet-KO mice. Consistently, we show that HGF acts through p38α to upregulate antioxidant enzymes in cardiomyocytes. Our results highlight that HGF/Met signaling in cardiomyocytes plays a physiological cardio-protective role in adult mice by acting as an endogenous regulator of heart function through oxidative stress control.This work was supported by grants: (AFM)-13683 from Association Française contre les myopathies, France, FIS-PI07/0071 and SAF-2010-20198-C02-01 from Ministry of Science and Innovation, Spain, and grants from Comunidad de Madrid/Universidad Complutense de Madrid: CAM/UCM 920384 and UCM-BSCH 920384, Spain to A.P.; BFU2011-25304 from Ministry of Science and Innovation, Spain, RD12/0019/0022 (TerCel network, ISCIII), P11-CTS-7564 (Junta de Andalucía) to R. M.-Ch.; FRM (Fondation pour la Recherche Médicale), Fondation Bettencourt-Schueller, and Association Française contre les myopathies (AFM) to F.M.; SAF2010-15881 from Ministry of Science and Innovation, Spain, and RD012/0021 (RedinRen network, ISCIII), and GR100 (Junta de Castilla y León) to J.M. L.-N. The cardiovascular phenotyping unit of the University of Salamanca, including the telemetry equipment, has been acquired with the support of the European Regional Development Funds (FEDER).Peer Reviewe

C3G is upregulated in hepatocarcinoma, contributing to tumor growth and progression and to HGF/MET pathway activation

[EN]The complexity of hepatocellular carcinoma (HCC) challenges the identification of disease-relevant signals. C3G, a guanine nucleotide exchange factor for Rap and other Ras proteins, plays a dual role in cancer acting as either a tumor suppressor or promoter depending on tumor type and stage. The potential relevance of C3G upregulation in HCC patients suggested by database analysis remains unknown. We have explored C3G function in HCC and the underlying mechanisms using public patient data and in vitro and in vivo human and mouse HCC models. We found that C3G is highly expressed in progenitor cells and neonatal hepatocytes, whilst being down-regulated in adult hepatocytes and re-expressed in human HCC patients, mouse HCC models and HCC cell lines. Moreover, high C3G mRNA levels correlate with tumor progression and a lower patient survival rate. C3G expression appears to be tightly modulated within the HCC program, influencing distinct cell biological properties. Hence, high C3G expression levels are necessary for cell tumorigenic properties, as illustrated by reduced colony formation in anchorage-dependent and -independent growth assays induced by permanent C3G silencing using shRNAs. Additionally, we demonstrate that C3G down-regulation interferes with primary HCC tumor formation in xenograft assays, increasing apoptosis and decreasing proliferation. In vitro assays also revealed that C3G down-regulation enhances the pro-migratory, invasive and metastatic properties of HCC cells through an epithelial-mesenchymal switch that favors the acquisition of a more mesenchymal phenotype. Consistently, a low C3G expression in HCC cells correlates with lung metastasis formation in mice. However, the subsequent restoration of C3G levels is associated with metastatic growth. Mechanistically, C3G down-regulation severely impairs HGF/MET signaling activation in HCC cells. Collectively, our results indicate that C3G is a key player in HCC. C3G promotes tumor growth and progression, and the modulation of its levels is essential to ensure distinct biological features of HCC cells throughout the oncogenic program. Furthermore, C3G requirement for HGF/MET signaling full activation provides mechanistic data on how it works, pointing out the relevance of assessing whether high C3G levels could identify HCC responders to MET inhibitors

C3G downregulation induces the acquisition of a mesenchymal phenotype that enhances aggressiveness of glioblastoma cells

© The Author(s) 2021.Glioblastoma (GBM) is the most aggressive tumor from the central nervous system (CNS). The current lack of efficient therapies makes essential to find new treatment strategies. C3G, a guanine nucleotide exchange factor for some Ras proteins, plays a dual role in cancer, but its function in GBM remains unknown. Database analyses revealed a reduced C3G mRNA expression in GBM patient samples. C3G protein levels were also decreased in a panel of human GBM cell lines as compared to astrocytes. Based on this, we characterized C3G function in GBM using in vitro and in vivo human GBM models. We report here that C3G downregulation promoted the acquisition of a more mesenchymal phenotype that enhanced the migratory and invasive capacity of GBM cells. This facilitates foci formation in anchorage-dependent and -independent growth assays and the generation of larger tumors in xenografts and chick chorioallantoic membrane (CAM) assays, but with a lower cell density, as proliferation was reduced. Mechanistically, C3G knock-down impairs EGFR signaling by reducing cell surface EGFR through recycling inhibition, while upregulating the activation of several other receptor tyrosine kinases (RTKs) that might promote invasion. In particular, FGF2, likely acting through FGFR1, promoted invasion of C3G-silenced GBM cells. Moreover, ERKs mediate this invasiveness, both in response to FGF2- and serum-induced chemoattraction. In conclusion, our data show the distinct dependency of GBM tumors on C3G for EGF/EGFR signaling versus other RTKs, suggesting that assessing C3G levels may discriminate GBM patient responders to different RTK inhibition protocols. Hence, patients with a low C3G expression might not respond to EGFR inhibitors.This work was supported by grants from the Spanish Ministry of Economy and Competitiveness [SAF2016-76588-C2-1-R and PID2019-104143RB-C22 to AP; and SAF2016-76588-C2-2-R and PID2019-104143RB-C21 to CG], and by two grants from the Council of Education of Junta de Castilla y León, Spain [SA017U16 and SA078P20 to CG]. All funding was cosponsored by the European FEDER Program. SM and OH are recipients of FPU fellowships from Spanish Ministry of Education. CS was supported by a fellowship from Complutense University from Madrid. A G-U and MRF are supported by Madrid Community Program for Talent Attraction (MRF 2017-T1/BMD-5468). P. B. received support from BBVA (Becas Leonardo 2018, BBM-TRA-0041)

Intraventricular neurocysticercosis in a migrant from Honduras

We report in Madrid (Spain) a case of intraventricular neurocysticercosis in a migrant from Choluteca (Honduras) confirmed by epidemiological, radiological and microbiological criteria.S

C3G, through its GEF activity, induces megakaryocytic differentiation and proplatelet formation

[Background]: Megakaryopoiesis allows platelet formation, which is necessary for coagulation, also playing an important role in different pathologies. However, this process remains to be fully characterized. C3G, an activator of Rap1 GTPases, is involved in platelet activation and regulates several differentiation processes. [Methods]: We evaluated C3G function in megakaryopoiesis using transgenic mouse models where C3G and C3GΔCat (mutant lacking the GEF domain) transgenes are expressed exclusively in megakaryocytes and platelets. In addition, we used different clones of K562, HEL and DAMI cell lines with overexpression or silencing of C3G or GATA-1. [Results]: We found that C3G participates in the differentiation of immature hematopoietic cells to megakaryocytes. Accordingly, bone marrow cells from transgenic C3G, but not those from transgenic C3GΔCat mice, showed increased expression of the differentiation markers CD41 and CD61, upon thrombopoietin treatment. Furthermore, C3G overexpression increased the number of CD41+ megakaryocytes with high DNA content. These results are supported by data obtained in the different models of megakaryocytic cell lines. In addition, it was uncovered GATA-1 as a positive regulator of C3G expression. Moreover, C3G transgenic megakaryocytes from fresh bone marrow explants showed increased migration from the osteoblastic to the vascular niche and an enhanced ability to form proplatelets. Although the transgenic expression of C3G in platelets did not alter basal platelet counts, it did increase slightly those induced by TPO injection in vivo. Moreover, platelet C3G induced adipogenesis in the bone marrow under pathological conditions. [Conclusions]: All these data indicate that C3G plays a significant role in different steps of megakaryopoiesis, acting through a mechanism dependent on its GEF activity.This work was supported by grants from the Spanish Ministry of Economy and Competitiveness [SAF2013–48210-C2–1-R and SAF2016–76588-C2–2-R to CG, SAF2013–48210-C2–2-R and SAF2016–76588-C2–1-R to AP], and by two grants from the Council of Education of Junta de Castilla y León, Spain [SA157A12–1 and SA017U16 to CG]. All funding was cosponsored by the European FEDER Program

Met signaling in cardiomyocytes is required for normal cardiac function in adult mice.

Hepatocyte growth factor (HGF) and its receptor, Met, are key determinants of distinct developmental processes. Although HGF exerts cardio-protective effects in a number of cardiac pathologies, it remains unknown whether HGF/Met signaling is essential for myocardial development and/or physiological function in adulthood. We therefore investigated the requirement of HGF/Met signaling in cardiomyocyte for embryonic and postnatal heart development and function by conditional inactivation of the Met receptor in cardiomyocytes using the Cre-α-MHC mouse line (referred to as α-MHCMet-KO). Although α-MHCMet-KO mice showed normal heart development and were viable and fertile, by 6 months of age, males developed cardiomyocyte hypertrophy, associated with interstitial fibrosis. A significant upregulation in markers of myocardial damage, such as β-MHC and ANF, was also observed. By the age of 9 months, α-MHCMet-KO males displayed systolic cardiac dysfunction. Mechanistically, we provide evidence of a severe imbalance in the antioxidant defenses in α-MHCMet-KO hearts involving a reduced expression and activity of catalase and superoxide dismutase, with consequent reactive oxygen species accumulation. Similar anomalies were observed in females, although with a slower kinetics. We also found that Met signaling down-regulation leads to an increase in TGF-β production and a decrease in p38MAPK activation, which may contribute to phenotypic alterations displayed in α-MHCMet-KO mice. Consistently, we show that HGF acts through p38α to upregulate antioxidant enzymes in cardiomyocytes. Our results highlight that HGF/Met signaling in cardiomyocytes plays a physiological cardio-protective role in adult mice by acting as an endogenous regulator of heart function through oxidative stress control.Comunidad de Madrid/Universidad Complutense de Madrid; Association Française contre les Myopathies; Seventh Framework Programme; Fondation pour la Recherche Médicale; Instituto de Salud Carlos III; Ministerio de Ciencia e Innovación; Fondation Bettencourt Schueller; European Regional Development Fund; Junta de Andalucía; Junta de Castilla y Leó

Educación lectora, fácil lectura y nuevas identidades educativas: Desafíos y posibilidades desde la inclusión y la interculturalidad

Prólogo / Aldo Ocampo González (pp. 11-12). -- La experiencia como textura: la lectura de textos como experiencia / Andrea Verónica Pérez (pp. 17-37). -- Educación de adultos en Escuelas Cárceles de Chile / Marianela Ruiz Quezada (pp. 39-85). -- Comprensión lectora e interculturalidad: tensiones y desafíos del curriculum nacional / Marcela Amaya García (pp. 89-119). -- Enseñanza de la escritura intercultural / Rosario Arroyo González (pp. 121-147). -- Lectura y escritura a partir de la intertextualidad / Genoveva Ponce Naranjo (pp. 149-161). -- A manos abiertas. Diversidad sorda: lectura intercultural / Gina Morales Acosta y Amelia Castillo (pp. 163-183). -- El podcast y el club de lectura para padres: propuestas de promoción de la lectura para personas con discapacidad intelectual / Almudena Revilla Guijarro (pp. 187-208). -- ¿Cómo fomentar la lectura en niños y jóvenes con discapacidad intelectual?, desafíos desde la educación inclusiva y la neurodidáctica / Aldo Ocampo González (pp. 210-245). -- Recursos y estrategias para la enseñanza del español como lengua extranjera: el programa de escritura científico-virtualizado on-line / Abraham Francisco Jiménez Baena (pp. 247-255). -- La lectura, herramienta de acceso y creación: generación de espacios lectores para la instalación de un curriculo intercultural / Viviana Zepeda Barraza (pp. 257-274). -- La estrategia de fácil lectura en el contexto de aulas con diversidad lingüística: análisis de datos en la ciudad de Buenos Aires / Analia Gutiérrez (pp. 276-286). -- Educación democrática y multiculturalidad: un aporte a la accesibilidad cognitiva desde la filosofía del derecho / Jesús Ignacio Delgado Rojas (pp. 288-297). -- Democracia lectora, disenso social y ciudadanías en disputa: ¿cómo entender los desafíos del fomento y la animación de la lectura desde una perspectiva de Educación inclusiva? / Aldo Ocampo González (pp. 299-364)

The imperative for quality control programs in Monkeypox virus DNA testing by PCR: CIBERINFEC quality control

© 2023 The Authors. Journal of Medical Virology published by Wiley Periodicals LLC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.To evaluate molecular assays for Mpox diagnosis available in various clinical microbiology services in Spain through a quality control (QC) approach. A total of 14 centers from across Spain participated in the study. The Reference Laboratory dispatched eight serum samples and eight nucleic acid extracts to each participating center. Some samples were spiked with Mpox or Vaccinia virus to mimic positive samples for Mpox or other orthopox viruses. Participating centers provided information on the results obtained, as well as the laboratory methods used. Among the 14 participating centers seven different commercial assays were employed, with the most commonly used kit being LightMix Modular Orthopox/Monkeypox (Mpox) Virus (Roche®). Of the 12 centers conducting Mpox determinations, concordance ranged from 62.5% (n = 1) to 100% (n = 11) for eluates and from 75.0% (n = 1) to 100% (n = 10) for serum. Among the 10 centers performing Orthopoxvirus determinations, a 100% concordance was observed for eluates, while for serum, concordance ranged from 87.5% (n = 6) to 100% (n = 4). Repeatedly, 6 different centers reported a false negative in serum samples for Orthopoxvirus diagnosis, particularly in a sample with borderline Ct = 39. Conversely, one center, using the TaqMan™ Mpox Virus Microbe Detection Assay (Thermo Fisher), reported false positives in Mpox diagnosis for samples spiked with vaccinia virus due to cross-reactions. We observed a positive correlation of various diagnostic assays for Mpox used by the participating centers with the reference values. Our results highlight the significance of standardization, validation, and ongoing QC in the microbiological diagnosis of infectious diseases, which might be particularly relevant for emerging viruses.This research was supported by CIBER (Strategic Action for Monkeypox)—Consorcio Centro de Investigación Biomédica en Red—(CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea—NextGenerationEU. A. d. S. is supported by ‘Instituto de Salud Carlos III’ (grant number JR22/00055).Peer reviewe

Gerentur: Una aplicación transversal de gamificación para la estadística en turismo y ciencias económicas

Depto. de Economía Financiera y Actuarial y EstadísticaFac. de Ciencias Económicas y EmpresarialesFALSEsubmitte

C3G down-regulates p38 MAPK activity in response to stress by Rap-1 independent mechanisms: Involvement in cell death

We present here evidences supporting a negative regulation of p38α MAPK activity by C3G in MEFs triggered by stress, which can mediate cell death or survival depending on the stimuli. Upon serum deprivation, C3G induces survival through inhibition of p38α activation, which mediates apoptosis. In contrast, in response to H2O2, C3G behaves as a pro-apoptotic molecule, as its knock-down or knock-out enhances survival through up-regulation of p38α activation, which plays an anti-apoptotic role under these conditions. Moreover, the C3G target, Rap-1, plays an opposite role, also through regulation of p38α MAPK activity. Our data also suggest that changes in the protein levels of some members of the Bcl-2 family could account for the regulation of cell death by C3G and/or Rap-1 through p38α MAPK. Bim/Bcl-xL ratio appears to be important in the regulation of cell survival, both upon serum deprivation and in response to H2O2. In addition, the increase in BNIP-3 levels induced by C3G knock-down in wt cells treated with H2O2 might play a role preventing cell death. Therefore, we can conclude that C3G is a negative regulator of p38α MAPK in MEFs, while Rap-1 is a positive regulator, but both, through the regulation of p38α activity, can promote cell survival or cell death depending on the stimuli. © 2009 Elsevier Inc. All rights reserved.This work was supported by grants FIS-PI041131 and FIS-PI070071 (CG: FISPI041324 and FIS-PI070078) from ISCIII, Ministry of Science and Innovation, Spain; and grants from Comunidad de Madrid/Universidad Complutense de Madrid: CAM/UCM 920384 (CCG07-UCM/SAL-2148), Spain. A.G.-U. is a predoctoral student supported by Comunidad de Madrid, Spain. V.M is a predoctoral student supported by grant FISPI070078.Peer Reviewe