NQO1-Dependent Redox Cycling of Idebenone: Effects on Cellular Redox Potential and Energy Levels

Short-chain quinones are described as potent antioxidants and in the case of idebenone have already been under clinical investigation for the treatment of neuromuscular disorders. Due to their analogy to coenzyme Q10 (CoQ10), a long-chain quinone, they are widely regarded as a substitute for CoQ10. However, apart from their antioxidant function, this provides no clear rationale for their use in disorders with normal CoQ10 levels. Using recombinant NAD(P)H:quinone oxidoreductase (NQO) enzymes, we observed that contrary to CoQ10 short-chain quinones such as idebenone are good substrates for both NQO1 and NQO2. Furthermore, the reduction of short-chain quinones by NQOs enabled an antimycin A-sensitive transfer of electrons from cytosolic NAD(P)H to the mitochondrial respiratory chain in both human hepatoma cells (HepG2) and freshly isolated mouse hepatocytes. Consistent with the substrate selectivity of NQOs, both idebenone and CoQ1, but not CoQ10, partially restored cellular ATP levels under conditions of impaired complex I function. The observed cytosolic-mitochondrial shuttling of idebenone and CoQ1 was also associated with reduced lactate production by cybrid cells from mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) patients. Thus, the observed activities separate the effectiveness of short-chain quinones from the related long-chain CoQ10 and provide the rationale for the use of short-chain quinones such as idebenone for the treatment of mitochondrial disorders

Diversi modi di favorire la comprensione dei testi scritti: un protocollo sperimentale

Si riporta la metodologia di un protocollo sperimentale per confrontare gli effetti sulla comprensione di diverse forme di modificazione testuale. I soggetti sono adolescenti parlanti nativi e non nativi dell'italiano

Regionalisation of Nitrogen Balances with the CAPRI Model (RegNiBal): Pilot project in support of the Eurostat Working Group on Agri-Environmental Indicators

The report presents the results of the pilot project “Regionalisation of Gross Nitrogen Balances with the CAPRI model” (RegNiBal), which was carried out by Joint Research Centre in cooperation with Eurostat and delegates from the volunteering countries (France, Germany, Hungary and Italy). The objective of the pilot project was to evaluate the differences between national Eurostat/OECD Gross Nitrogen Balances (GNB) and the GNB calculated using the CAPRI model, with the overall goal of using the CAPRI model to (operationally) provide regional GNB data to complement the national GNBs.JRC.H.4-Monitoring Agricultural Resource

SDHA and SDHB mutations in KIT/PDGFRA WT gastrointestinal stromal tumors

Background: KIT/PDGFRA wild-type (WT) GISTs harbour mutations on SDHB and SDHC and, more recently, we described mutations on SDHA using massively parallel sequencing approach. We sequenced SDHA and SDHB genes in a larger series in order to validate the data. Methods: SDHA gene (1-15 exons) and SDHB gene (1-8 exons) (even not all exons in all samples) were sequenced on tumor (T) and/or peripheral blood (PB) of WT GIST patients by Sanger Sequencing method. DNA was extracted from tumor specimens by the QIAmp DNA Mini kit (Qiagen, Milan, Italy) and amplified with specific primer pairs designed to amplify exons but not SDHA pseudo-genes located on chromosomes 3 and 5. Then, PCR products were purified with the Qiaquick PCR purification kit (Qiagen, Milan, Italy) and sequenced on both strands using the Big Dye Terminator v1.1 Cycle Sequencing kit (Applied Biosystems). Sanger sequencing was performed on ABI 3730 Genetic Analyzer (Applied Biosystems). Results: SDHA gene exons were sequenced on a total of 27 WT GIST patients, in particular on T, PB and both from 12, 6 and 9 patients respectively. SDHB gene exons were sequenced on a total of 18 out of 27 patients, in particular on T, PB and both from 7, 8 and 3 patients respectively. 8 SDHA mutations were found in 5 samples (18.5%). Besides those previously identified, 5 new SDHA mutations were found in other 3 samples: one sample harboured R171C and R589Q heterozygous missense mutation in exons 5 and 13 respectively. The other one harboured G419R and E564K heterozygous missense mutations in exons 9 and 13 respectively. The third sample harboured a delCAG immediately upstream of exon 5, in heterozygosis on PB and in homozygosis on T. A SDHB heterozygous mutation (301delT) in exon 4 was found on 1 PB sample. Conclusions: the presence of SDHA mutations has been confirmed in a subgroup of WT GIST patients. All subunits of SDH complex should be sequenced on WT GIST patients in order to explore the frequency and any linkage between each other and the pathogenetic and clinical significance

COVID-19 Severity and androgen receptor polymorphism

During the COVID-19 pandemic, the most severe form of the disease was most often seen in male patients. The aim of this study was to identify any male predispositions that could be used to predict the outcome of the disease and enable early intervention. We investigated CAG polymorphism in the androgen receptor gene and serum levels of testosterone and LH, which were considered as probably responsible for this predisposition. The study involved 142 patients who had recovered from COVID-19 at least three months previously and were classified according to their disease severity using theWorld Health Organization (WHO) classification. We observed a significant increase in the number of CAG repeats with increasing disease severity: the percentage of patients with more than 23 repeats increased two-fold from Grade I to Grade IV. Furthermore, testosterone levels were significantly lower in patients with severe disease. Reduced androgenic signaling could predispose men to a more severe form: low testosterone levels and a reduced androgen receptor activity (CAG > 23) expose the host to an excessive inflammatory response, leading downstream to the multi-organ damage seen in severe COVID-1

A distinct pediatric-type gastrointestinal stromal tumor in adults: potential role of succinate dehydrogenase subunit A mutations.

Comment on: "Pediatric-type" gastrointestinal stromal tumors in adults: distinctive histology predicts genotype and clinical behavior. Rege TA, Wagner AJ, Corless CL, Heinrich MC, Hornick JL. Am J Surg Pathol. 2011 Apr; 35(4):495-504

Tocilizumab for patients with COVID-19 pneumonia. The single-arm TOCIVID-19 prospective trial

BackgroundTocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients.MethodsA multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival.ResultsIn the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6-24.0, P=0.52) and 22.4% (97.5% CI: 17.2-28.3, P<0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline.ConclusionsTocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline.Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092)