Prenatal expression of thioredoxin reductase 1 (TRXR1) and microsomal glutathione transferase 1 (MGST1) in humans

AbstractThioredoxin reductase 1 (TRXR1) and microsomal glutathione transferase 1 (MGST1) are important redox and detoxifying enzymes in adult life. The aim of this study was to investigate the expression of these enzymes during fetal life. In addition, the role of gene methylation was studied since this might play an important role in the on-and-off switch of gene expression between fetal and adult life.To this end, the expression of the TRXR1-encoding gene TXNRD1 and the MGST1-encoding gene MGST1 was studied in fetal tissues. The mean mRNA expression of TXNRD1 in fetal livers were seven times higher compared to the mean expression in adult livers (p<0.001). Of the six studied splice variants of TXNRD1, four had a significantly higher expression in the fetal livers as compared to adult livers. The mean expression of MGST1 was twofold higher in adult compared to fetal liver tissue (p=0.01). For MGST1 the alternative first exon 1B was the predominant splice variant in both fetal and adult liver samples. The highest mRNA expression of both TXNRD1 and MGST1 was found in fetal adrenals, whereas expression was lower in fetal liver, lungs and kidneys. There was a significant correlation between the hepatic expression of TXNRD1 and MGST1. Treatment with the demethylating agent 5-AZA resulted in decreased levels of TXNRD1 in human liver HepG2 cells but did not affect the expression of MGST1.In conclusion, the expression of TXNRD1 is higher in fetuses than in adults and might be of importance during fetal life. Hepatic TXNRD1 and MGST1 are co-expressed in both fetuses and adults suggesting common regulatory mechanisms

Lipophilicity predicts the ability of nonsulphonylurea drugs to block pancreatic beta-cell KATP channels and stimulate insulin secretion: statins as a test case

Aims KATP ion channels play a key role in glucose‐stimulated insulin secretion. However, many drugs block KATP as “off targets” leading to hyperinsulinaemia and hypoglycaemia. As such drugs are often lipophilic, the aim was to examine the relationship between drug lipophilicity (P) and IC50 for KATP block and explore if the IC50's of statins could be predicted from their lipophilicity and whether this would allow one to forecast their acute action on insulin secretion. Materials and methods A meta‐analysis of 26 lipophilic, nonsulphonylurea, blockers of KATP was performed. From this, the IC50's for pravastatin and simvastatin were predicted and then tested experimentally by exploring their effects on KATP channel activity via patch‐clamp measurement, calcium imaging and insulin secretion in murine beta cells and islets. Results Nonsulphonylurea drugs inhibited KATP channels with a Log IC50 linearly related to their logP. Simvastatin blocked KATP with an IC50 of 25 nmol/L, a value independent of cytosolic factors, and within the range predicted by its lipophilicity (21‐690 nmol/L). 10 μmol/L pravastatin, predicted IC50 0.2‐12 mmol/L, was without effect on the KATP channel. At 10‐fold therapeutic levels, 100 nmol/L simvastatin depolarized the beta‐cell membrane potential and stimulated Ca2+ influx but did not affect insulin secretion; the latter could be explained by serum binding. Conclusions The logP of a drug can aid prediction for its ability to block beta‐cell KATP ion channels. However, although the IC50 for the block of KATP by simvastatin was predicted, the difference between this and therapeutic levels, as well as serum sequestration, explains why hypoglycaemia is unlikely to be observed with acute use of this statin

Functional SARS-CoV-2 cross-reactive CD4+ T cells established in early childhood decline with age.

Pre-existing SARS-CoV-2-reactive T cells have been identified in SARS-CoV-2-unexposed individuals, potentially modulating COVID-19 and vaccination outcomes. Here, we provide evidence that functional cross-reactive memory CD4+ T cell immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is established in early childhood, mirroring early seroconversion with seasonal human coronavirus OC43. Humoral and cellular immune responses against OC43 and SARS-CoV-2 were assessed in SARS-CoV-2-unexposed children (paired samples at age two and six) and adults (age 26 to 83). Pre-existing SARS-CoV-2-reactive CD4+ T cell responses targeting spike, nucleocapsid, and membrane were closely linked to the frequency of OC43-specific memory CD4+ T cells in childhood. The functional quality of the cross-reactive memory CD4+ T cell responses targeting SARS-CoV-2 spike, but not nucleocapsid, paralleled OC43-specific T cell responses. OC43-specific antibodies were prevalent already at age two. However, they did not increase further with age, contrasting with the antibody magnitudes against HKU1 (β-coronavirus), 229E and NL63 (α-coronaviruses), rhinovirus, Epstein-Barr virus (EBV), and influenza virus, which increased after age two. The quality of the memory CD4+ T cell responses peaked at age six and subsequently declined with age, with diminished expression of interferon (IFN)-γ, interleukin (IL)-2, tumor necrosis factor (TNF), and CD38 in late adulthood. Age-dependent qualitative differences in the pre-existing SARS-CoV-2-reactive T cell responses may reflect the ability of the host to control coronavirus infections and respond to vaccination

Quality indicators as a tool in improving the introduction of new medicines

Quality indicators are increasingly used as a tool to achieve safe and quality clinical care, cost-effective therapy, for professional learning, remuneration, accreditation and financial incentives. A substantial number focus on drug therapy but few address the introduction of new medicines even though this is a burning issue. The objective was to describe the issues and challenges in designing and implementing a transparent indicator framework and evaluation protocol for the introduction of new medicines and to provide guidance on how to apply quality indicators in the managed entry of new medicines. Quality indicators need to be developed early to assess whether new medicines are introduced appropriately. A number of key factors need to be addressed when developing, applying and evaluating indicators including dimensions of quality, suggested testing protocols, potential data sources, key implementation factors such as intended and unintended consequences, budget impact and cost-effectiveness, assuring the involvement of the medical professions, patients and the public, and reliable and easy-to-use computerized tools for data collection and management. Transparent approaches include the need for any quality indicators developed to handle conflict of interests to enhance their validity and acceptance. The suggested framework and indicator testing protocol may be useful in assessing the applicability of indicators for new medicines and may be adapted to healthcare settings worldwide. The suggestions build on existing literature to create a field testing methodology that can be used to produce country-specific quality indicators for new medicines as well as a cross international approach to facilitate access to new medicines

Identification and validation of novel biomarkers and therapeutics for pulpitis using connectivity mapping

International audienceAim To create an irreversible pulpitis gene signature from microarray data of healthy and inflamed dental pulps, followed by a bioinformatics approach using connectivity mapping to identify therapeutic compounds that could potentially treat pulpitis. Methodology The Gene Expression Omnibus (GEO) database, an international public repositor

Assessment of the effect of betaine on p16 and c-myc DNA methylation and mRNA expression in a chemical induced rat liver cancer model

<p>Abstract</p> <p>Background</p> <p>The development and progression of liver cancer may involve abnormal changes in DNA methylation, which lead to the activation of certain proto-oncogenes, such as <it>c-myc</it>, as well as the inactivation of certain tumor suppressors, such as <it>p16</it>. Betaine, as an active methyl-donor, maintains normal DNA methylation patterns. However, there are few investigations on the protective effect of betaine in hepatocarcinogenesis.</p> <p>Methods</p> <p>Four groups of rats were given diethylinitrosamine (DEN) and fed with AIN-93G diets supplemented with 0, 10, 20 or 40 g betaine/kg (model, 1%, 2%, and 4% betaine, respectively), while the control group, received no DEN, fed with AIN-93G diet. Eight or 15 weeks later, the expression of <it>p16 </it>and <it>c-myc </it>mRNA was examined by Real-time PCR (Q-PCR). The DNA methylation status within the <it>p16 </it>and <it>c-myc </it>promoter was analyzed using methylation-specific PCR.</p> <p>Results</p> <p>Compared with the model group, numbers and areas of glutathione S-transferase placental form (GST-p)-positive foci were decreased in the livers of the rats treated with betaine (<it>P < 0.05</it>). Although the frequency of <it>p16 </it>promoter methylation in livers of the four DEN-fed groups appeared to increase, there is no difference among these groups after 8 or 15 weeks (<it>P > 0.05</it>). Betaine supplementation attenuated the down-regulation of <it>p16 </it>and inhibited the up-regulation of <it>c-myc </it>induced by DEN in a dose-dependent manner (<it>P </it>< 0.01). Meanwhile, increases in levels of malondialdehyde (MDA) and glutathione S-transferase (GST) in model, 2% and 4% betaine groups were observed (<it>P < 0.05</it>). Finally, enhanced antioxidative capacity (T-AOC) was observed in both the 2% and 4% betaine groups.</p> <p>Conclusion</p> <p>Our data suggest that betaine attenuates DEN-induced damage in rat liver and reverses DEN-induced changes in mRNA levels.</p

Anti-Inflammatory Effect of Fluvastatin on IL-8 Production Induced by Pseudomonas aeruginosa and Aspergillus fumigatus Antigens in Cystic Fibrosis

International audienceBACKGROUND: Early in life, patients with cystic fibrosis (CF) are infected with microorganisms including bacteria and fungi, particularly Pseudomonas aeruginosa and Aspergillus fumigatus. Since recent research has identified the anti-inflammatory properties of statins (besides their lipid-lowering effects), we investigated the effect of fluvastatin on the production of the potent neutrophil chemoattractant chemokine, IL-8, in whole blood from CF patients, stimulated by Pseudomonas aeruginosa (LPS) and Aspergillus fumigatus (AFA) antigens. RESULTS: Whole blood from adult patients with CF and from healthy volunteers was collected at the Rennes University Hospital (France). Blood was pretreated for 1 h with fluvastatin (0-300 µM) and incubated for 24 h with LPS (10 µg/mL) and/or AFA (diluted 1/200). IL-8 protein levels, quantified by ELISA, were increased in a concentration-dependent manner when cells were stimulated by LPS or AFA. Fluvastatin strongly decreased the levels of IL-8, in a concentration-dependent manner, in whole blood from CF patients. However, its inhibitory effect was decreased or absent in whole blood from healthy subjects. Furthermore, the inhibition induced by fluvastatin in CF whole blood was reversed in the presence of intermediates within the cholesterol biosynthesis pathway, mevalonate, farnesyl pyprophosphate or geranylgeranyl pyrophosphate that activate small GTPases by isoprenylation. CONCLUSIONS: For the first time, the inhibitory effects of fluvastatin on CF systemic inflammation may reveal the important therapeutic potential of statins in pathological conditions associated with the over-production of pro-inflammatory cytokines and chemokines as observed during the manifestation of CF. The anti-inflammatory effect could be related to the modulation of the prenylation of signalling proteins

Policy change and the National Essential Medicines List development process in Brazil between 2000 and 2014 : has the Essential Medicine concept been abandoned?

Brazil has had a National Essential Medicines List (EML) since 1964. From 2000 to 2010, five consecutive evidence-based editions were produced, building on the essential medicines concept. In 2012, the government changed course to establish a new paradigm, introducing adoption of new medicines as the main aim within the recommendation process. The objective of the paper is to report efforts to develop Brazil´s national EML, policy changes from 2000 to 2014, discussing results, challenges, and perspectives. Brazilian EML history and development process were collected from legislation, minutes, reports and legal ordinances, from 2000 to 2014. The Brazilian EML and the WHO Model lists were compared using the Anatomical Therapeutic Chemical system. Overlap between lists was verified and linear trends were produced. Type of membership, inclusion criteria, procedures, flow and listed medicines varied greatly between the selection committees acting before and after 2012. Paradigm-changing legislation aiming at linking list compliance to public financing in 2012 produced (i) greater importance given to political and administrative stakeholders, (ii) increasing trends in number of medicines over the years, (iii) decrease in use of WHO Model List as a reference, (iv) substitution of an essential medicines list review and update process by an adoption decision output. Other issues remained unchanged. Insufficient efforts for list implementation, such as lack of physician education, presented consequences to the health system. Substantial efforts were made to produce and update the list from 2000 to 2014. However, continuous and intense health litigation disproves process outcome effectiveness