Caracterització d'una nova proteïna de Solanum tuberosum, PHOR1, involucrada en la via de senyalització de les giberl·lines

Consultable des del TDXTítol obtingut de la portada digitalitzadaLes giberelines bioactives (GAs) modulen moltes respostes durant el creixement i desenvolupament de les plantes, inclosa la germinació de les llavors, l'expansió de les fulles, l'elongació de la tija, la iniciació de la floració i el desenvolupament del fruit i la llavor. Un altre procés controlat per les GAs és la tuberització a les patateres. En la formació de tubercles, que es troba fortament influenciada pel fotoperiode, està descrit que les GAs tenen un clar efecte inhibidor de la tuberització. La tuberització és en general induïda pels fotoperiodes de dies curts (SD), en algunes especies de patatera però els dies curts són un requisit per a que formin tubercles, com a Solanum demisum i algunes línies de Solanum tuberosum ssp. andigena. Aquestes espècies només tuberitzen en condicions de dies curts i no tuberitzen en condicions de dies llargas (LD) o SD suplementat amb un "night-breack" (SD+NB). Tractaments amb inhibidors de la biosíntesi de les GAs, ancimidol o paclobutrazol, poden promoure la tuberització en aquestes plantes en condicions no inductores de LD. La sobreexpressió o la inhibició de l'expressió del gen biosintétic GA 20-oxidasa StGA20ox1, en les plantes de patatera d'andigena transgèniques presenten una tuberització en condicions de SD retardada i primerenca, respectivament. Aquestes dades estableixen una possitiva correlació entre la disminució de l'activitat de les GAs i la inducció de la tuberització en aquestes plantes. Més evidències del paper de les GAs en la inhibició de la formació de tubercles en condicions no inductures es va posar de manifest al aïllar un mutant d'andigena, ga1, que presenta un bloqueix en la biosíntesi de les GAs i que pot tuberitzar, després de moltes setmanes, en LDs. Aquestes observacions poden ser interpretades com indicatives de que les dos vies regulatòries independentes controlen la inducció de la tuberització, la via del fotoperiode i la via de les GAs, en el que la disminució en la biosintesi i/o el transport de les GAs als estolons o una reducció en la resposta a les GAs poden estar regulats per la inducció fotoperiòdica. Utilitzant RT-PCR "differential display" de fulles de plantes crescudes en condicions inductores i no inductores (SD+NB), hem aïllat un clon anomenar PHOR1 (per photoperiod responsive 1) que codifica per una proteïna homòloga al domini "arm-repeat" de la proteïna de segmentació polaritzada armadillo de Drosophila. L'expressió del gen de PHOR1 oscil·la amb un ritme diurn, que en plantes induïdes per a la tuberització presenten dos pics del transcrit. La inhibició antisentit de l'expressió de PHOR1 a les plantes transgèniques produeixen un fenotit semi-nan similar al de les plantes deficients en GAs. Les línies transgèniques pel gen PHOR1 presenten internodes curts, una reducció en la llargària dels pecíols i fulles de color verd fosc i en condicons de SD tuberitzen abans que les plantes control. Les curves de dosi resposta a l'aplicació de GAs exògenes demostresn que les línies trangèniques antisentit presenten una disminució en la resposta, vers un increment de la reposta a les GAs en les plantes transgèniques que sobreexpressen la proteïna PHOR1. La mesura dels nivells endògens de GAs evidencien un increment d'aquests en les plantes transgèniques amb nivells reduïts de PHOR1. Una altre evidència de l'implicació en la resposta de les GAs, és el resultat dels anàlisis Northern que confirmaven que la regulació per "feedback" dels nivells dels tràncrits de la GA 20-oxidasa i la GA 2-oxidasa estaven alterats a aquestes línies. Estudis de localització subcel·lular utilitzant una expressió transitòria de la proteïna fusionada a la GFP mostraren que les GAs indueixen una ràpida migració de la proteïna de fusió PHOR1-GFP del citoplasma al nucli de la cèl·lula. Aquests resultats indiquen que PHOR1 és un component de la via de transducció de senyal de les GAs, que media la inducció de la via de les GAs mitjançant la seva localització nuclear.Bioactive gibberellins (GAs) modulate many responses during plant growth and development, including seed germination, leaf expansion, stem elongation, flower initiation and seed and fruit development. Another well documented plant developmental process controlled by GAs is tuberization in potato. Tuber formation is strongly influenced by day length, with GAs reported to have an inhibitory effect on tuber induction. Tuberization is in general promoted by short-days (SD), with short photoperiods being an absolute requirement for tuber formation in some wild-species of potato, like Solanum demissum or some lines of S. tuberosum ssp. andigena. These species tuberize only in SD conditions, and do not produce tubers when grown in long-days (LD) or SD supplemented with a night-break (SD+NB). Treatments with the inhibitors of GA-biosynthesis, ancymidol or paclobutrazol, are able to promote tuberization of these plants under non-inductive LD conditions. Over-expression or antisense inhibition of the GA 20-oxidase StGA20ox1 gene in transgenic potato andigena plants results in, respectively, delayed or early tuberization under SD conditions. Therefore, these data establish a positive correlation between decreased GA activity and tuber induction in these species. Strong evidence for a role of GAs in inhibition of tuber formation under non-inductive conditions derives also from the observation that the andigena ga1 mutant, blocked in GA biosynthesis, can form tubers after several weeks in LDs. These observations can be interpreted as indicative of two independent regulatory pathways controlling tuber induction, i.e. a photoperiod pathway and a GA pathway, with a decrease in GA synthesis and/or transport to the stolons or a reduced responsiveness to GAs being able to partly overcome the requirement for photoperiodic induction. Using RT-PCR differential display of leaves from plants grown under inducing (SD) and non-inducing (SD+NB) conditions, we have isolated clone PHOR1 (photoperiod responsive 1) encoding an arm-repeat protein with homology to the Drosophila segment polarity protein armadillo. Expression of the PHOR1 gene oscillates with a diurnal rhythm that, in plants induced for tuberization, is characterized by two peaks of transcript around dawn and dusk. Antisense inhibition of PHOR1 expression in transgenic plants produces a semi-dwarf phenotype similar to GA-deficient plants. The antisense PHOR1 lines exhibit shorter internodes, reduced petiole length and broader leaves, and under SD conditions tuberize earlier than controls. Dose-response curves to exogenous GA showed that GA-response is reduced in the antisense lines, while an enhanced response to GAs is detected in transgenic lines over-expressing the PHOR1 protein. Measurements of endogenous GA levels evidenced that GA content is increased in the antisense plants with reduced levels of PHOR1 expression. As evidence of an impaired GA response, northern analyses confirmed that feedback regulation of the GA 20-oxidase and GA 2-oxidase transcripts was altered in these lines. Subcellular localization studies using a translational fusion to GFP showed that GAs induced a rapid migration of the PHOR1-GFP fusion protein from the cytoplasm to the nucleus. These results indicate that PHOR1 may function in GA signal transduction by mediating nuclear signalling of the GA-induced pathway

The risk of COVID-19 death is much greater and age dependent with type I IFN autoantibodies

International audienceSignificance There is growing evidence that preexisting autoantibodies neutralizing type I interferons (IFNs) are strong determinants of life-threatening COVID-19 pneumonia. It is important to estimate their quantitative impact on COVID-19 mortality upon SARS-CoV-2 infection, by age and sex, as both the prevalence of these autoantibodies and the risk of COVID-19 death increase with age and are higher in men. Using an unvaccinated sample of 1,261 deceased patients and 34,159 individuals from the general population, we found that autoantibodies against type I IFNs strongly increased the SARS-CoV-2 infection fatality rate at all ages, in both men and women. Autoantibodies against type I IFNs are strong and common predictors of life-threatening COVID-19. Testing for these autoantibodies should be considered in the general population

The risk of COVID-19 death is much greater and age dependent with type I IFN autoantibodies

International audienceSignificance There is growing evidence that preexisting autoantibodies neutralizing type I interferons (IFNs) are strong determinants of life-threatening COVID-19 pneumonia. It is important to estimate their quantitative impact on COVID-19 mortality upon SARS-CoV-2 infection, by age and sex, as both the prevalence of these autoantibodies and the risk of COVID-19 death increase with age and are higher in men. Using an unvaccinated sample of 1,261 deceased patients and 34,159 individuals from the general population, we found that autoantibodies against type I IFNs strongly increased the SARS-CoV-2 infection fatality rate at all ages, in both men and women. Autoantibodies against type I IFNs are strong and common predictors of life-threatening COVID-19. Testing for these autoantibodies should be considered in the general population

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

BackgroundWe previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in similar to 80% of cases.MethodsWe report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded.ResultsNo gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P=1.1x10(-4)) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70[95%CI 1.3-8.2], P=2.1x10(-4)). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR=19.65[95%CI 2.1-2635.4], P=3.4x10(-3)), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR=4.40[9%CI 2.3-8.4], P=7.7x10(-8)). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P=1.68x10(-5)).ConclusionsRare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old

Correction: Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

International audienc

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research