Transcriptómica en diferentes condiciones de madurez del fruto de genotipos de tomate (Solanum lycopersicum) que discrepan para la vida poscosecha de los frutos

El tomate Solanum lycopersicum L., por su genoma pequeño, un ciclo de vida corto, mutantes de maduración bien caracterizados, ricos recursos genómicos e importancia comercial ha sido utilizado como modelo en estudios de maduración de frutos climatéricos, así como para dilucidar las bases genéticas y epigenética de numerosos caracteres de interés agronómico. Varios mutantes de maduración importantes, incluidos CNR, RIN y NOR han proporcionado nuevos conocimientos sobre el control de los procesos de maduración. Estos genes, que bloquean o alargan el proceso de la madurez, confieren larga vida poscosecha a los frutos, pero producen efectos indeseados sobre la calidad debido a su acción pleiotrópica sobre las vías metabólicas que brindan un adecuado sabor, aroma, textura, etc. Se ha demostrado que los frutos de las formas silvestres S. lycopersicum var. cerasiforme y S. pimpinellifolium tienen mayor vida poscosecha que los cultivares comerciales de tomate pero menor que los genotipos homocigotas para los mutantes de madurez del fruto nor y rin de S. lycopersicum y que esta prolongación de la vida poscosecha se logra sin detrimentos de otros caracteres de calidad organoléptica. A pesar de que S. lycopersicum y S. pimpinellifolium tienen diferencias fenotípicas extremas, existen relativamente pocas diferencias entre las especies de tomates silvestres y cultivadas a nivel de secuencia del genoma (cercanas al 0,6%). De acuerdo con esto, se ha postulado que las diferencias fenotípicas se deben a las funciones de las proteínas y, en consecuencia a la regulación del transcriptoma. Muchos de los procesos bioquímicos y metabólicos asociados con la maduración de los frutos requieren cambios en la expresión de cientos a miles de genes. Los estudios de expresión diferencial ayudan a comprender el control del crecimiento y desarrollo de las plantas y a identificar puntos de control específicos del metabolismo. La técnica denominada ADNc-AFLP (Polimorfismo de longitud de fragmento amplificado basado en ADNc), ha sido ya utilizada como una primera aproximación transcriptómica a los procesos moleculares asociados a la madurez del fruto. La regulación de la expresión génica es un proceso complejo que puede ocurrir en varios niveles, principalmente a nivel transcripcional con la acción coordinada los elementos cis-regulatorios presentes en los promotores y que son reconocidas por los factores que actúan en trans. En el presente trabajo se pretende: 1- Identificar genes con expresión diferencial en frutos que maduran en planta y en estantería en genotipos discrepantes para la vida poscosecha de tomate y 2- Describir y analizar in silico el rol de los promotores y los elementos reguladores que actúan en cis en la regulación de la expresión. Para ello se utilizaron los siguientes genotipos de S. lycopersicum: el cv Caimanta, (madurez normal) y el cv Nor (entrada 804627, mutante para el gen nor). Los genotipos silvestres: S. lycopersicum var cerasiforme (entrada LA1385) y S. pimpinellifolium (entrada LA722) con genes que prolongan la vida poscosecha. Al comparar, los perfiles de expresión obtenidos por ADNc-AFLP se observó menor cantidad de fragmentos derivados de transcriptos (FDTs) totales en todos los genotipos cuando los frutos maduran en estantería (2481), en comparación con aquellos que lo hacen en planta (2660). Además, se evidenció que la cantidad total de genes, como así también los genes específicos que se activan o reprimen, dependen del genotipo, en particular cuando el fruto madura en estantería. Por el contrario, durante la maduración del fruto en la planta, la cantidad total y específica de genes que se expresan es independiente del genotipo, indicando que dicho proceso parece ser similar entre ellos. El genotipo NOR, contrariamente a lo esperado, mostró la mayor cantidad de FDTs (fragmentos derivados de un transcripto) totales y específicos del sitio de maduración, lo que evidenciaría que otros genes que se encuentran activos escapan a la modulación del factor de transcripción codificado por el gen nor. Se logró identificar y validar por RT-qPCR genes que evidenciaron expresión diferencial detectados por ADNc-AFLP. El análisis funcional de estos genes mostró que la respuesta a estrés fue la función con más representación en los frutos que maduraron en planta. El análisis in silico de los elementos cis-regulatorios de la región promotora de los genes con expresión diferencial en planta y estantería, evidenció diferencias estructurales. La localización de los motivos cis en genes expresados en frutos que maduran en estantería sugiere que estos genes podrían estar regulados en la región proximal. Por el contrario, en planta un 48,8% de los elementos cis-regulatorios se localizaron más alejados del codon ATG, lo que dejaría suponer una regulación en la región distal. Estos resultados permitieron un acercamiento a los posibles mecanismos de control, vinculando la maduración de los frutos con la respuesta a estrés. Además, estos resultados reforzarían por un lado, las diferencias fenotípicas existente entre los genotipos y por otro la influencia del sitio de maduración (planta o estantería), sobre la expresión génica en frutos de tomate.Fil: Apellido, Nombre. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Souza Canada, Eduardo Daniel. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin

Effect of SGLT2 Inhibitors on Stroke and Atrial Fibrillation in Diabetic Kidney Disease: Results From the CREDENCE Trial and Meta-Analysis

BACKGROUND AND PURPOSE: Chronic kidney disease with reduced estimated glomerular filtration rate or elevated albuminuria increases risk for ischemic and hemorrhagic stroke. This study assessed the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on stroke and atrial fibrillation/flutter (AF/AFL) from CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation) and a meta-analysis of large cardiovascular outcome trials (CVOTs) of SGLT2i in type 2 diabetes mellitus.METHODS: CREDENCE randomized 4401 participants with type 2 diabetes mellitus and chronic kidney disease to canagliflozin or placebo. Post hoc, we estimated effects on fatal or nonfatal stroke, stroke subtypes, and intermediate markers of stroke risk including AF/AFL. Stroke and AF/AFL data from 3 other completed large CVOTs and CREDENCE were pooled using random-effects meta-analysis.RESULTS: In CREDENCE, 142 participants experienced a stroke during follow-up (10.9/1000 patient-years with canagliflozin, 14.2/1000 patient-years with placebo; hazard ratio [HR], 0.77 [95% CI, 0.55-1.08]). Effects by stroke subtypes were: ischemic (HR, 0.88 [95% CI, 0.61-1.28]; n=111), hemorrhagic (HR, 0.50 [95% CI, 0.19-1.32]; n=18), and undetermined (HR, 0.54 [95% CI, 0.20-1.46]; n=17). There was no clear effect on AF/AFL (HR, 0.76 [95% CI, 0.53-1.10]; n=115). The overall effects in the 4 CVOTs combined were: total stroke (HRpooled, 0.96 [95% CI, 0.82-1.12]), ischemic stroke (HRpooled, 1.01 [95% CI, 0.89-1.14]), hemorrhagic stroke (HRpooled, 0.50 [95% CI, 0.30-0.83]), undetermined stroke (HRpooled, 0.86 [95% CI, 0.49-1.51]), and AF/AFL (HRpooled, 0.81 [95% CI, 0.71-0.93]). There was evidence that SGLT2i effects on total stroke varied by baseline estimated glomerular filtration rate (P=0.01), with protection in the lowest estimated glomerular filtration rate (<45 mL/min/1.73 m2]) subgroup (HRpooled, 0.50 [95% CI, 0.31-0.79]).CONCLUSIONS: Although we found no clear effect of SGLT2i on total stroke in CREDENCE or across trials combined, there was some evidence of benefit in preventing hemorrhagic stroke and AF/AFL, as well as total stroke for those with lowest estimated glomerular filtration rate. Future research should focus on confirming these data and exploring potential mechanisms. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02065791

Reduction of cardiac imaging tests during the COVID-19 pandemic: The case of Italy. Findings from the IAEA Non-invasive Cardiology Protocol Survey on COVID-19 (INCAPS COVID)

Background: In early 2020, COVID-19 massively hit Italy, earlier and harder than any other European country. This caused a series of strict containment measures, aimed at blocking the spread of the pandemic. Healthcare delivery was also affected when resources were diverted towards care of COVID-19 patients, including intensive care wards. Aim of the study: The aim is assessing the impact of COVID-19 on cardiac imaging in Italy, compare to the Rest of Europe (RoE) and the World (RoW). Methods: A global survey was conducted in May–June 2020 worldwide, through a questionnaire distributed online. The survey covered three periods: March and April 2020, and March 2019. Data from 52 Italian centres, a subset of the 909 participating centres from 108 countries, were analyzed. Results: In Italy, volumes decreased by 67% in March 2020, compared to March 2019, as opposed to a significantly lower decrease (p < 0.001) in RoE and RoW (41% and 40%, respectively). A further decrease from March 2020 to April 2020 summed up to 76% for the North, 77% for the Centre and 86% for the South. When compared to the RoE and RoW, this further decrease from March 2020 to April 2020 in Italy was significantly less (p = 0.005), most likely reflecting the earlier effects of the containment measures in Italy, taken earlier than anywhere else in the West. Conclusions: The COVID-19 pandemic massively hit Italy and caused a disruption of healthcare services, including cardiac imaging studies. This raises concern about the medium- and long-term consequences for the high number of patients who were denied timely diagnoses and the subsequent lifesaving therapies and procedures

Impact of COVID-19 on Diagnostic Cardiac Procedural Volume in Oceania: The IAEA Non-Invasive Cardiology Protocol Survey on COVID-19 (INCAPS COVID)

Objectives: The INCAPS COVID Oceania study aimed to assess the impact caused by the COVID-19 pandemic on cardiac procedure volume provided in the Oceania region. Methods: A retrospective survey was performed comparing procedure volumes within March 2019 (pre-COVID-19) with April 2020 (during first wave of COVID-19 pandemic). Sixty-three (63) health care facilities within Oceania that perform cardiac diagnostic procedures were surveyed, including a mixture of metropolitan and regional, hospital and outpatient, public and private sites, and 846 facilities outside of Oceania. The percentage change in procedure volume was measured between March 2019 and April 2020, compared by test type and by facility. Results: In Oceania, the total cardiac diagnostic procedure volume was reduced by 52.2% from March 2019 to April 2020, compared to a reduction of 75.9% seen in the rest of the world (p<0.001). Within Oceania sites, this reduction varied significantly between procedure types, but not between types of health care facility. All procedure types (other than stress cardiac magnetic resonance [CMR] and positron emission tomography [PET]) saw significant reductions in volume over this time period (p<0.001). In Oceania, transthoracic echocardiography (TTE) decreased by 51.6%, transoesophageal echocardiography (TOE) by 74.0%, and stress tests by 65% overall, which was more pronounced for stress electrocardiograph (ECG) (81.8%) and stress echocardiography (76.7%) compared to stress single-photon emission computerised tomography (SPECT) (44.3%). Invasive coronary angiography decreased by 36.7% in Oceania. Conclusion: A significant reduction in cardiac diagnostic procedure volume was seen across all facility types in Oceania and was likely a function of recommendations from cardiac societies and directives from government to minimise spread of COVID-19 amongst patients and staff. Longer term evaluation is important to assess for negative patient outcomes which may relate to deferral of usual models of care within cardiology

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used