METTL15 introduces N4-methylcytidine into human mitochondrial 12S rRNA and is required for mitoribosome biogenesis.

Post-transcriptional RNA modifications, the epitranscriptome, play important roles in modulating the functions of RNA species. Modifications of rRNA are key for ribosome production and function. Identification and characterization of enzymes involved in epitranscriptome shaping is instrumental for the elucidation of the functional roles of specific RNA modifications. Ten modified sites have been thus far identified in the mammalian mitochondrial rRNA. Enzymes responsible for two of these modifications have not been characterized. Here, we identify METTL15, show that it is the main N4-methylcytidine (m4C) methyltransferase in human cells and demonstrate that it is responsible for the methylation of position C839 in mitochondrial 12S rRNA. We show that the lack of METTL15 results in a reduction of the mitochondrial de novo protein synthesis and decreased steady-state levels of protein components of the oxidative phosphorylation system. Without functional METTL15, the assembly of the mitochondrial ribosome is decreased, with the late assembly components being unable to be incorporated efficiently into the small subunit. We speculate that m4C839 is involved in the stabilization of 12S rRNA folding, therefore facilitating the assembly of the mitochondrial small ribosomal subunits. Taken together our data show that METTL15 is a novel protein necessary for efficient translation in human mitochondria.Medical Research Council, UK [MC_UU_00015/4]; EMBO [ALFT 701-2013 to L.V.H]; ‘Fundação para a Ciência e a Tecnologia’ [PD/BD/105750/2014 to P.R.-G.]

Intracellular delivery of an anionic antisense oligonucleotide via receptor-mediated endocytosis

We describe the synthesis and characterization of a 5′ conjugate between a 2′-O-Me phosphorothioate antisense oligonucleotide and a bivalent RGD (arginine–glycine–aspartic acid) peptide that is a high-affinity ligand for the αvβ3 integrin. We used αvβ3-positive melanoma cells transfected with a reporter comprised of the firefly luciferase gene interrupted by an abnormally spliced intron. Intranuclear delivery of a specific antisense oligonucleotide (termed 623) corrects splicing and allows luciferase expression in these cells. The RGD–623 conjugate or a cationic lipid-623 complex produced significant increases in luciferase expression, while ‘free’ 623 did not. However, the kinetics of luciferase expression was distinct; the RGD–623 conjugate produced a gradual increase followed by a gradual decline, while the cationic lipid-623 complex caused a rapid increase followed by a monotonic decline. The subcellular distribution of the oligonucleotide delivered using cationic lipids included both cytoplasmic vesicles and the nucleus, while the RGD–623 conjugate was primarily found in cytoplasmic vesicles that partially co-localized with a marker for caveolae. Both the cellular uptake and the biological effect of the RGD–623 conjugate were blocked by excess RGD peptide. These observations suggest that the bivalent RGD peptide–oligonucleotide conjugate enters cells via a process of receptor-mediated endocytosis mediated by the αvβ3 integrin

Current issues in medically assisted reproduction and genetics in Europe: research, clinical practice, ethics, legal issues and policy. European Society of Human Genetics and European Society of Human Reproduction and Embryology.

In March 2005, a group of experts from the European Society of Human Genetics and European Society of Human Reproduction and Embryology met to discuss the interface between genetics and assisted reproductive technology (ART), and published an extended background paper, recommendations and two Editorials. Seven years later, in March 2012, a follow-up interdisciplinary workshop was held, involving representatives of both professional societies, including experts from the European Union Eurogentest2 Coordination Action Project. The main goal of this meeting was to discuss developments at the interface between clinical genetics and ARTs. As more genetic causes of reproductive failure are now recognised and an increasing number of patients undergo testing of their genome before conception, either in regular health care or in the context of direct-to-consumer testing, the need for genetic counselling and preimplantation genetic diagnosis (PGD) may increase. Preimplantation genetic screening (PGS) thus far does not have evidence from randomised clinical trials to substantiate that the technique is both effective and efficient. Whole-genome sequencing may create greater challenges both in the technological and interpretational domains, and requires further reflection about the ethics of genetic testing in ART and PGD/PGS. Diagnostic laboratories should be reporting their results according to internationally accepted accreditation standards (International Standards Organisation - ISO 15189). Further studies are needed in order to address issues related to the impact of ART on epigenetic reprogramming of the early embryo. The legal landscape regarding assisted reproduction is evolving but still remains very heterogeneous and often contradictory. The lack of legal harmonisation and uneven access to infertility treatment and PGD/PGS fosters considerable cross-border reproductive care in Europe and beyond. The aim of this paper is to complement previous publications and provide an update of selected topics that have evolved since 2005

Examination performance with flipped classroom as instructional strategy in the carbohydrate metabolism course unit at a Philippine medical school: Estimation of average treatment effect from observational data

While the innovativeness of the flipped classroom (FC) approach promotes active participation and higher-order thinking among students, there are concerns about its effectiveness in terms of knowledge retention. Currently, there are no studies involving medical school biochemistry that evaluate this aspect of effectiveness. Thus, we conducted a historical control study that analyzed observational data from two freshman batches of the Doctor of Medicine program in our institution. Class 2021 (n = 250) served as the traditional lecture (TL) group while Class 2022 (n = 264) served as the FC group. Data on relevant observed covariates (age, sex, National Medical Admission Test or NMAT score, undergraduate degree) and the outcome variable (carbohydrate metabolism course unit examination percentage scores, as indicator of knowledge retention) were included in the analysis. Propensity scores were calculated using logit regression conditional on these observed covariates. Afterwards, 1:1 nearest-neighbor propensity score matching (PSM) was performed to produce an estimated average treatment effect (ATE) measure afforded by FC (as adjusted mean difference in examination scores between the two batches), balancing on the covariates. Nearest-neighbor matching using the calculated propensity scores effectively balanced the two groups (standardized bias \u3c10%), producing 250 matched student-pairs that received either TL or FC. Following PSM, the FC group was found to have a significantly higher adjusted mean examination score compared to the TL group (adjusted mean difference = 5.62%, 95% CI: 2.54%, 8.72%; p \u3c 0.001). Using this approach, we were able to demonstrate benefit of FC over TL in terms of knowledge retention, as reflected by the estimated ATE

Mitochondrial DNA variations are associated with recurrent pregnancy loss

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. Cases with three or more consecutive spontaneous abortions before the 20th week of gestation are termed as recurrent pregnancy loss (RPL). Problems in implantation of the foetus and any retarded growth of the foetus in the uterus can be correlated to RPL. Possible causes of RPL would include the genetic variations in the regulatory enzymes of the crucial metabolic pathways, clotting factors, hormones and hormone receptors. This defect of the mitochondrial respiratory chain is recognized as a major cause of human disease. We investigated 73 women with RPL and 100 healthy normal controls. By using the direct sequencing method, the amplified products including the mtDNA complex I genes were analyzed. Overall, seven variations in mitochondrial complex I genes were found (T4216C, A5153G, C10142T, C12062T, A12662G, G14179A and T14263C) using direct sequencing technique. The RPL group had significantly higher proportions of the different variants than those observed of the control group. In conclusion, more research is essentially needed to understand the effect and role of the mitochondrial variations in the progress of RPL, which may vary among individuals and different ethnic groups

A Meta-analysis on the Effect of Kangaroo Mother Care on Preterm Mortality

Background. Kangaroo mother care (KMC) is a low-cost but high-impact intervention for preterm and low birth weight (LBW) infants. Objectives. To determine the effect of KMC on in-hospital mortality among preterm and LBW infants, taking into consideration their gestational age, birth weight, income category of the country of birth, and medical stability. Materials and Methods. A comprehensive search of several databases, as well as local listings of research papers, was performed to look for randomized controlled studies with KMC as intervention, and mortality and length of hospitalization as outcome measures. The risk of bias and publication bias was assessed. We did subgroup analyses based on income category of the country of birth, gestational age, birth weight, and medical stability of the infants. Results. Sixteen randomized controlled trials (RCTs) with 1738 infants in the KMC group and 1674 infants in the control group were included. Based on the GRADE approach, although all the studies were RCTs, the evidence is assessed as moderate certainty due to the nature of the intervention (KMC) that prevented blinding. There was a 41% reduction in risk of dying among preterm and low birth weight infants who received KMC compared to conventional medical care (3.86%% vs 6.87%; RR = 0.59, 95% CI 0.44, 0.79; I2 = 0%; number needed to treat for additional benefit (NNTB) = 34; 16 RCTs; 3,412 infants). Furthermore, there were also reductions in the risk of dying among infants who were (KMC: 4.32% vs CMC: 8.17%, RR = 0.55, 95% CI 0.38, 0.79; I2 = 0%; NNTB = 26; 10 RCTs; 1795 infants), with birthweight of \u3e1500 g (KMC: 3.97% vs CMC: 6.83%, RR = 0.60; 95% CI 0.45, 0.82; I2 = 0%; NNTB = 35; 10 RCTs; 2960 infants), and born in low- and middle income countries (LMIC) (3.77% vs 6.95%; RR = 0.57, 95% CI 0.43, 0.77; I2 = 0%; NNTB = 32; 14 RCTs; 3281 infants). There was a significant reduction in mortality (KMC: 11.05% vs CMC: 20.94%; RR = 0.54; 95% CI 0.34, 0.87; I2 = 0%; NNTB = 11; 5 RCTs; 387 infants) even among medically unstable infants who received KMC compared to those who did not. The length of hospitalization did not significantly differ between the KMC and the control groups. Due to high heterogeneity, subgroup analyses were performed, which showed a trend towards a shorter length of hospital stay among preterm infants AOG, with birthweight ≥1500 g, medically unstable during admission, and belonging to LMIC but did not reach statistical significance. Conclusion. There was moderate certainty evidence that KMC can decrease mortality among preterm and LBW infants. Furthermore, KMC was beneficial among relatively more premature, bigger, medically unstable preterm infants and born in low to middle-income countries

Thermo-tectonic history of the Issyk-Kul basement (Kyrgyz Northern Tien Shan, Central Asia)

Abstract not availableJohan De Grave, Stijn Glorie, Mikhail M. Buslov, Daniel F. Stockli, Michael O. McWilliams, Vladislav Yu. Batalev, Peter Van den haut

FK506 reduces neuroinflammation and dopaminergic neurodegeneration in an alpha-synuclein-based rat model for Parkinson's disease

Alpha-synuclein (α-synuclein) is considered a key player in Parkinson's disease (PD), but the exact relationship between α-synuclein aggregation and dopaminergic neurodegeneration remains unresolved. There is increasing evidence that neuroinflammatory processes are closely linked to dopaminergic cell death, but whether the inflammatory process is causally involved in PD or rather reflects secondary consequences of nigrostriatal pathway injury is still under debate. We evaluated the therapeutic effect of the immunophilin ligand FK506 in a rAAV2/7 α-synuclein overexpression rat model. Treatment with FK506 significantly increased the survival of dopaminergic neurons in a dose-dependent manner. No reduction in α-synuclein aggregation was apparent in this time window, but FK506 significantly lowered the infiltration of both T helper and cytotoxic T cells and the number and subtype of microglia and macrophages. These data suggest that the anti-inflammatory properties of FK506 decrease neurodegeneration in this α-synuclein-based PD model, pointing to a causal role of neuroinflammation in the pathogenesis of PD.publisher: Elsevier articletitle: FK506 reduces neuroinflammation and dopaminergic neurodegeneration in an α-synuclein-based rat model for Parkinson's disease journaltitle: Neurobiology of Aging articlelink: http://dx.doi.org/10.1016/j.neurobiolaging.2015.01.014 content_type: article copyright: Copyright © 2015 Elsevier Inc. All rights reserved.status: publishe