La historia de la Fisiología y otras ciencias afines a través de los Premios Nobel de Fisiología y Medicina: aprendizaje activo y colaborativo de los hitos científicos que cambian el mundo

Memoria ID-055 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2020-2021

Analysis of K-Ras Nuclear Expression in Fibroblasts and Mesangial Cells

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al[Background]: Ras GTPases are considered cytoplasmic proteins that must be localized to cell membranes for activation, and there are few evidences of the presence of any Ras isoform in nuclei of eukaryotic cells. [Methodology/Principal Findings]: Using conventional antibodies and inmunocytochemistry, differential centrifugation and western blot, we have observed the putative presence of K-Ras isoform in the nuclei of fibroblasts and mesangial cells. In order to avoid cross-reactions with other Ras isoforms, and using antibodies against K-Ras (R-3400, H3845-M01, sc-30) or pan-Ras (05-516, OP40) in cells that only expressed the K-Ras isoform (fibroblasts obtained from H-ras−/−,N-ras−/− mice) we also detected some nuclear positive expression. To further probe the identity of nuclear K-Ras, we have generated K-Ras knockout (K-ras−/−) embrionary fibroblasts by mating of K-ras+/− heterozygote mice. Using specific antibodies, only H- and N-Ras isoforms were observed in the cytoplasm of K-ras−/− fibroblasts. However, both K-Ras4A and K-Ras4B positive signals were detected by immunocytochemistry and Western blot with two commercial antibodies (sc-522 and sc-521 against each isoforms, respectively) in both cytoplasm and nuclei from K-ras−/− fibroblasts. [Conclusions/Significance]: We show that the presence of K-Ras4B in fibroblast nuclei, already described by other authors, is probably due to a cross-reaction of the antibody with an undetermined nucleolar protein. Although this study also shows the possible nuclear expression of K-Ras isoform in fibroblasts or in mesangial cells, it also reveals the importance of being cautious in these studies about distribution of protein isoforms due to some important limitations imposed by the unspecificity of the antibodies or contaminations in cellular preparations.This work was supported by grants from Instituto de Salud Carlos III (Ministerio de Sanidad y Consumo, CP03/00094, PI041817, PI021570 and C03/10), Comisión Interministerial de Ciencia y Tecnologí­a (BFU-2004-00285/BFI; SAF2003-04177), and Junta de Castilla y León (SA001/C05; SA029A05; GRS 167/A/07 and excellence group GR100).Peer reviewe

Effect of angiotensin II and small GTPase Ras signaling pathway inhibition on early renal changes in a murine model of obstructive nephropathy

This is an open access article distributed under the Creative Commons Attribution License.Tubulointerstitial fibrosis is a major feature of chronic kidney disease. Unilateral ureteral obstruction (UUO) in rodents leads to the development of renal tubulointerstitial fibrosis consistent with histopathological changes observed in advanced chronic kidney disease in humans. The purpose of this study was to assess the effect of inhibiting angiotensin II receptors or Ras activation on early renal fibrotic changes induced by UUO. Animals either received angiotensin II or underwent UUO. UUO animals received either losartan, atorvastatin, and farnesyl transferase inhibitor (FTI) L-744,832, or chaetomellic acid A (ChA). Levels of activated Ras, phospho-ERK1/2, phospho-Akt, fibronectin, and α-smooth muscle actin were subsequently quantified in renal tissue by ELISA, Western blot, and/or immunohistochemistry. Our results demonstrate that administration of angiotensin II induces activation of the small GTPase Ras/Erk/Akt signaling system, suggesting an involvement of angiotensin II in the early obstruction-induced activation of renal Ras. Furthermore, upstream inhibition of Ras signalling by blocking either angiotensin AT1 type receptor or by inhibiting Ras prenylation (atorvastatin, FTI o ChA) reduced the activation of the Ras/Erk/Akt signaling system and decreased the early fibrotic response in the obstructed kidney. This study points out that pharmacological inhibition of Ras activation may hold promise as a future strategy in the prevention of renal fibrosis.This study was supported by grants from Ministerio de Economía y Competitividad (Grant SAF2010-15881 and Red de Investigacion Cooperativa en Enfermedades Renales REDINREN RD12/0021/0032), Junta de Castilla y León (Grant SA 001/C05 and Excellence Group GR100), and REDINREN which is an initiative of the Instituto de Salud Carlos III of Spain supported by FEDER funds. When performing the present study, Ana B. Rodríguez-Pena was a fellow of the Fundacion Renal “Iñigo Ávarez de Toledo” and Neil G. Docherty was a fellow ofThe Marie Curie Programme, EU.Peer Reviewe

Turnover time of fluorescent dissolved organic matter in the dark global ocean

Research articleMarine dissolved organic matter (DOM) is one of the largest reservoirs of reduced carbon on Earth. In the dark ocean (4200 m), most of this carbon is refractory DOM. This refractory DOM, largely produced during microbial mineralization of organic matter, includes humic-like substances generated in situ and detectable by fluorescence spectroscopy. Here we show two ubiquitous humic-like fluorophores with turnover times of 435±41 and 610±55 years, which persist significantly longer than the B350 years that the dark global ocean takes to renew. In parallel, decay of a tyrosine-like fluorophore with a turnover time of 379±103 years is also detected. We propose the use of DOM fluorescence to study the cycling of resistant DOM that is preserved at centennial timescales and could represent a mechanism of carbon sequestration (humic-like fraction) and the decaying DOM injected into the dark global ocean, where it decreases at centennial timescales (tyrosine-like fraction).Versión del editor10,015

Efecto protector de melatonina en la degeneración de la retina

FISIOLOGÍA DE LA RETINA: La retina es un tejido sensible a la luz que se encuentra en la superficie interior del ojo. La retina adulta está constituida por 6 tipos de células neuronales y otras no neuronales que se ordenan en capas formando una estructura laminar altamente organizada. Desde su parte más interna, es decir, aquella que está en contacto con la hialoides posterior del vítreo, hasta la más externa, que está en contacto con la coroides, se encuentran las siguientes capas: - Membrana limitante interna: contacta con el vítreo y está formada por los procesos internos de las células de Müller. - Capa de fibras nerviosas de la retina: principalmente axones de las células ganglionares en su trayecto hacia la papila óptica...

Innovación y estrategias de intervención en acoso escolar

Los problemas de convivencia escolar, violencia escolar, bullying y cyberbullying, en los centros españoles son una realidad y, por tanto, es necesario que los futuros docentes cuenten con estrategias específicas para el abordaje de estas situaciones cuando se enfrenten a la realidad de las aulas. En este manual, profesionales del área de la convivencia escolar presentan las actuaciones, programas y herramientas disponibles que en estos momentos se están poniendo en práctica en los centros escolares con resultados positivos. Así, se pretende ampliar el conocimiento teórico-práctico en el ámbito de la convivencia, gestión de conflictos y violencia escolar.EducaciónPsicologí

Long-term treatment with chaethomellic acid A reduces glomerulosclerosis and arteriolosclerosis in a rat model of chronic kidney disease

The high prevalence of end-stage renal disease emphasizes the failure to provide therapies to effectively prevent and/or reverse renal fibrosis. Therefore, the aim of this study was to evaluate the effect of long-term treatment with chaethomellic acid A (CAA), which selectively blocks Ha-Ras farnesylation, on renal mass reduction-induced renal fibrosis. Male Wistar rats were sham-operated (SO) or subjected to 5/6 renal mass reduction (RMR). One week after surgery, rats were placed in four experimental groups: SO:SO rats without treatment (n = 13); SO + CAA: SO rats treated with CAA (n = 13); RMR:RMR rats without treatment (n = 14); and RMR + CAA:RMR rats treated with CAA (n = 13). CAA was intraperitoneally administered in a dose of 0.23 μg/kg three times a week for six months. Renal fibrosis was evaluated by two-dimensional ultrasonography and histopathological analysis. The kidneys of the RMR animals treated with CAA showed a significantly decrease in the medullary echogenicity (p < 0.05) compared with the RMR rats that received no treatment. Glomerulosclerosis and arteriolosclerosis scores were significantly lower (p < 0.001) in the RMR + CAA group when compared with the RMR group. There were no significant differences in interstitial fibrosis, interstitial inflammation and tubular dilatation scores between the RMR + CAA and RMR groups. These data suggest that CAA can be a potential future drug to attenuate the progression of chronic kidney disease.This work is supported by : European Investment Funds by FEDER/COMPETE/POCI– Operacional Competitiveness and Internacionalization Programme, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013; and by European Investment Funds by FEDER/COMPETE/POCI– Operacional Competitiveness and Internacionalization Programme, under Project POCI-01-0145-FEDER-016728 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project PTDC/DTP-DES/6077/2014.info:eu-repo/semantics/publishedVersio

Chromosomal instability in aneuploid acute lymphoblastic leukemia associates with disease progression

Chromosomal instability (CIN) lies at the core of cancer development leading to aneuploidy, chromosomal copy-number heterogeneity (chr-CNH) and ultimately, unfavorable clinical outcomes. Despite its ubiquity in cancer, the presence of CIN in childhood B-cell acute lymphoblastic leukemia (cB-ALL), the most frequent pediatric cancer showing high frequencies of aneuploidy, remains unknown. Here, we elucidate the presence of CIN in aneuploid cB-ALL subtypes using single-cell whole-genome sequencing of primary cB-ALL samples and by generating and functionally characterizing patient-derived xenograft models (cB-ALL-PDX). We report higher rates of CIN across aneuploid than in euploid cB-ALL that strongly correlate with intraclonal chr-CNH and overall survival in mice. This association was further supported by in silico mathematical modeling. Moreover, mass-spectrometry analyses of cB-ALL-PDX revealed a "CIN signature" enriched in mitotic-spindle regulatory pathways, which was confirmed by RNA-sequencing of a large cohort of cB-ALL samples. The link between the presence of CIN in aneuploid cB-ALL and disease progression opens new possibilities for patient stratification and offers a promising new avenue as a therapeutic target in cB-ALL treatment.</p

Risk Factors for COVID-19 in Inflammatory Bowel Disease: A National, ENEIDA-Based Case–Control Study (COVID-19-EII)

(1) Scant information is available concerning the characteristics that may favour the acquisition of COVID-19 in patients with inflammatory bowel disease (IBD). Therefore, the aim of this study was to assess these differences between infected and noninfected patients with IBD. (2) This nationwide case-control study evaluated patients with inflammatory bowel disease with COVID-19 (cases) and without COVID-19 (controls) during the period March-July 2020 included in the ENEIDA of GETECCU. (3) A total of 496 cases and 964 controls from 73 Spanish centres were included. No differences were found in the basal characteristics between cases and controls. Cases had higher comorbidity Charlson scores (24% vs. 19%; p = 0.02) and occupational risk (28% vs. 10.5%; p < 0.0001) more frequently than did controls. Lockdown was the only protective measure against COVID-19 (50% vs. 70%; p < 0.0001). No differences were found in the use of systemic steroids, immunosuppressants or biologics between cases and controls. Cases were more often treated with 5-aminosalicylates (42% vs. 34%; p = 0.003). Having a moderate Charlson score (OR: 2.7; 95%CI: 1.3-5.9), occupational risk (OR: 2.9; 95%CI: 1.8-4.4) and the use of 5-aminosalicylates (OR: 1.7; 95%CI: 1.2-2.5) were factors for COVID-19. The strict lockdown was the only protective factor (OR: 0.1; 95%CI: 0.09-0.2). (4) Comorbidities and occupational exposure are the most relevant factors for COVID-19 in patients with IBD. The risk of COVID-19 seems not to be increased by immunosuppressants or biologics, with a potential effect of 5-aminosalicylates, which should be investigated further and interpreted with caution

Correction : Chaparro et al. Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain: Large-Scale Epidemiological Study. J. Clin. Med. 2021, 10, 2885

The authors wish to make the following corrections to this paper [...]