Dysfunction of lipid sensor GPR120 leads to obesity in both mouse and human.

Free fatty acids provide an important energy source as nutrients, and act as signalling molecules in various cellular processes. Several G-protein-coupled receptors have been identified as free-fatty-acid receptors important in physiology as well as in several diseases. GPR120 (also known as O3FAR1) functions as a receptor for unsaturated long-chain free fatty acids and has a critical role in various physiological homeostasis mechanisms such as adipogenesis, regulation of appetite and food preference. Here we show that GPR120-deficient mice fed a high-fat diet develop obesity, glucose intolerance and fatty liver with decreased adipocyte differentiation and lipogenesis and enhanced hepatic lipogenesis. Insulin resistance in such mice is associated with reduced insulin signalling and enhanced inflammation in adipose tissue. In human, we show that GPR120 expression in adipose tissue is significantly higher in obese individuals than in lean controls. GPR120 exon sequencing in obese subjects reveals a deleterious non-synonymous mutation (p.R270H) that inhibits GPR120 signalling activity. Furthermore, the p.R270H variant increases the risk of obesity in European populations. Overall, this study demonstrates that the lipid sensor GPR120 has a key role in sensing dietary fat and, therefore, in the control of energy balance in both humans and rodents.

Relationship between salivary/pancreatic amylase and body mass index: a systems biology approach.

BACKGROUND: Salivary (AMY1) and pancreatic (AMY2) amylases hydrolyze starch. Copy number of AMY1A (encoding AMY1) was reported to be higher in populations with a high-starch diet and reduced in obese people. These results based on quantitative PCR have been challenged recently. We aimed to re-assess the relationship between amylase and adiposity using a systems biology approach. METHODS: We assessed the association between plasma enzymatic activity of AMY1 or AMY2, and several metabolic traits in almost 4000 French individuals from D.E.S.I.R. longitudinal study. The effect of the number of copies of AMY1A (encoding AMY1) or AMY2A (encoding AMY2) measured through droplet digital PCR was then analyzed on the same parameters in the same study. A Mendelian randomization analysis was also performed. We subsequently assessed the association between AMY1A copy number and obesity risk in two case-control studies (5000 samples in total). Finally, we assessed the association between body mass index (BMI)-related plasma metabolites and AMY1 or AMY2 activity. RESULTS: We evidenced strong associations between AMY1 or AMY2 activity and lower BMI. However, we found a modest contribution of AMY1A copy number to lower BMI. Mendelian randomization identified a causal negative effect of BMI on AMY1 and AMY2 activities. Yet, we also found a significant negative contribution of AMY1 activity at baseline to the change in BMI during the 9-year follow-up, and a significant contribution of AMY1A copy number to lower obesity risk in children, suggesting a bidirectional relationship between AMY1 activity and adiposity. Metabonomics identified a BMI-independent association between AMY1 activity and lactate, a product of complex carbohydrate fermentation. CONCLUSIONS: These findings provide new insights into the involvement of amylase in adiposity and starch metabolism.

A central role for GRB10 in regulation of islet function in man.

Variants in the growth factor receptor-bound protein 10 (GRB10) gene were in a GWAS meta-analysis associated with reduced glucose-stimulated insulin secretion and increased risk of type 2 diabetes (T2D) if inherited from the father, but inexplicably reduced fasting glucose when inherited from the mother. GRB10 is a negative regulator of insulin signaling and imprinted in a parent-of-origin fashion in different tissues. GRB10 knock-down in human pancreatic islets showed reduced insulin and glucagon secretion, which together with changes in insulin sensitivity may explain the paradoxical reduction of glucose despite a decrease in insulin secretion. Together, these findings suggest that tissue-specific methylation and possibly imprinting of GRB10 can influence glucose metabolism and contribute to T2D pathogenesis. The data also emphasize the need in genetic studies to consider whether risk alleles are inherited from the mother or the father.

Contribution of the low-frequency, loss-of-function p.R270H mutation in FFAR4 (GPR120) to increased fasting plasma glucose levels.

BACKGROUND: We previously reported that the low-frequency, loss-of-function variant p.R270H in FFAR4 encoding the lipid sensor GPR120 was associated with obesity. Gpr120-deficient mice develop obesity and both impaired fasting glucose and glucose intolerance under a high-fat diet. We aimed to assess the contribution of p.R270H to type 2 diabetes (T2D) risk and the variation of glucose-related traits. METHODS: We genotyped p.R270H in 8996 non-diabetic individuals (among whom 4523 had an oral glucose tolerance test (OGTT)) and in a T2D case-control study including 4725 cases and 4339 controls. The regression models were adjusted for age, sex and body mass index (BMI). RESULTS: We found a significant association between p.R270H and increased fasting glucose levels (ß=0.092±0.05 mmol/L; p=4.13×10(-4)). Furthermore, p.R270H nominally contributed to decreased homeostasis model of pancreatic ß-cell function (HOMA-B; ß=-0.090±0.06; p=6.01×10(-3)). Despite a high statistical power, we did not find any significant association between p.R270H and T2D risk or the variation of fasting insulin levels, the homeostasis model of insulin resistance or OGTT-derived indices. CONCLUSIONS: These results suggest that the low-frequency p.R270H variant which inhibits GPR120 activity might influence fasting glucose levels in a normal physiological range. This study does not exclude that other coding mutations in FFAR4 with stronger functional effect than p.R270H may be associated with T2D.

Variation in FTO contributes to childhood obesity and severe adult obesity.

We identified a set of SNPs in the first intron of the FTO (fat mass and obesity associated) gene on chromosome 16q12.2 that is consistently strongly associated with early-onset and severe obesity in both adults and children of European ancestry with an experiment-wise P value of 1.67 x 10(-26) in 2,900 affected individuals and 5,100 controls. The at-risk haplotype yields a proportion of attributable risk of 22% for common obesity. We conclude that FTO contributes to human obesity and hence may be a target for subsequent functional analyses.

Promoting the place of the allied health professions in clinical research.

Clinical research is of major importance to today's society, as scientific evidence is increasingly demanded as a basis for progress, whether this involves developing new healthcare products, improving clinical practice and care protocols or progress in prevention. Clinical research therefore requires professionals who are both experienced and increasingly well trained. Against this background, allied health professionals are becoming involved more and more, both as team members supporting clinical research projects and as managers or coordinators of projects in their own field. Clinical research activities provide an ideal opportunity for continuing professional development. All of this means that the professional skills of the allied health professions and clinical research support professions must be enhanced, their role promoted in the context of lecturer status and in the longer term, their status recognised by the supervisory authorities.

Two new Loci for body-weight regulation identified in a joint analysis of genome-wide association studies for early-onset extreme obesity in French and german study groups.

Meta-analyses of population-based genome-wide association studies (GWAS) in adults have recently led to the detection of new genetic loci for obesity. Here we aimed to discover additional obesity loci in extremely obese children and adolescents. We also investigated if these results generalize by estimating the effects of these obesity loci in adults and in population-based samples including both children and adults. We jointly analysed two GWAS of 2,258 individuals and followed-up the best, according to lowest p-values, 44 single nucleotide polymorphisms (SNP) from 21 genomic regions in 3,141 individuals. After this DISCOVERY step, we explored if the findings derived from the extremely obese children and adolescents (10 SNPs from 5 genomic regions) generalized to (i) the population level and (ii) to adults by genotyping another 31,182 individuals (GENERALIZATION step). Apart from previously identified FTO, MC4R, and TMEM18, we detected two new loci for obesity: one in SDCCAG8 (serologically defined colon cancer antigen 8 gene; p = 1.85x10(-8) in the DISCOVERY step) and one between TNKS (tankyrase, TRF1-interacting ankyrin-related ADP-ribose polymerase gene) and MSRA (methionine sulfoxide reductase A gene; p = 4.84x10(-7)), the latter finding being limited to children and adolescents as demonstrated in the GENERALIZATION step. The odds ratios for early-onset obesity were estimated at approximately 1.10 per risk allele for both loci. Interestingly, the TNKS/MSRA locus has recently been found to be associated with adult waist circumference. In summary, we have completed a meta-analysis of two GWAS which both focus on extremely obese children and adolescents and replicated our findings in a large followed-up data set. We observed that genetic variants in or near FTO, MC4R, TMEM18, SDCCAG8, and TNKS/MSRA were robustly associated with early-onset obesity. We conclude that the currently known major common variants related to obesity overlap to a substantial degree between children and adults.

Prediction of childhood obesity by infancy weight gain: an individual-level meta-analysis.

To assess the predictive ability of infant weight gain on subsequent obesity we performed a meta-analysis of individual-level data on 47,661 participants from 10 cohort studies from the UK, France, Finland, Sweden, the US and Seychelles. For each individual, weight SD scores at birth and age 1 year were calculated using the same external reference (British 1990). Childhood obesity was defined by International Obesity Task Force criteria. Each +1 unit increase in weight SD scores between 0 and 1 year conferred a twofold higher risk of childhood obesity (odds ratio = 1.97 [95% confidence interval (CI) 1.83, 2.12]), and a 23% higher risk of adult obesity (odds ratio = 1.23 [1.16, 1.30]), adjusted for sex, age and birthweight. There was little heterogeneity between studies. A risk score for childhood obesity comprising weight gain 0-1 year, mother's body mass index, birthweight and sex was generated in a random 50% selection of individuals from general population cohorts with available information (n = 8236); this score showed moderate predictive ability in the remaining 50% sample (area under receiving operating curve = 77% [95% CI 74, 80%]). A separate risk score for childhood overweight showed similar predictive ability (area under receiving operating curve = 76% [73, 79%]). In conclusion, infant weight gain showed a consistent positive association with subsequent obesity. A risk score combining birthweight and infant weight gain (or simply infant weight), together with mother's body mass index and sex may allow early stratification of infants at risk of childhood obesity.

European survey on national harmonization in clinical research.

BACKGROUND: Clinical trials remain key to the development of evidence-based medical practice. However, they are becoming increasingly complex, mainly in a multinational setting. To address these challenges, the European Union (EU) adopted the Clinical Trial Regulation EU No. 536/2014 (CTR). Once in force, the CTR will lead to more consistent rules and simplification of procedures for conducting clinical trials throughout the EU. Existing harmonization initiatives and "research infrastructures" for clinical trials may facilitate this process. This publication offers a snapshot of the current level of harmonization activities in academic clinical research in Europe. METHODS: A survey was performed among the member and observer countries of the European Clinical Research Infrastructure Network (ECRIN), using a standardized questionnaire. Three rounds of data collection were performed to maximize completeness and comparability of the received answers. The survey aimed to describe the harmonization of academic clinical research processes at national level, to facilitate the exchange of expertise and experience among countries, and to identify new fields of action. RESULTS: Most scientific partners already have in place various working groups and harmonization activities at national level. Furthermore, they are involved in and open to sharing their know-how and documents. Since harmonization was mainly a bottom-up approach up until now, the extent and topics dealt with are diverse and there is only little cross-networking and cross-country exchange so far. CONCLUSIONS: Currently, the ECRIN member countries offer a very solid base and collaborative spirit for further aligning processes and exchanging best practices for clinical research in Europe. They can support a smooth implementation of the EU CTR and may act as single contact with consolidated expertise in a country.

Pathophysiology of insulin resistance in small for gestational age subjects: a role for adipose tissue?

Over the last 15 years a number of long-term health risks associated with reduced fetal growth have been identified, including cardiovascular diseases, hypertension, dyslipidemia, or type 2 diabetes. A common feature of these conditions is insulin resistance, which is thought to play a pathogenic role. However, despite abundant data in the literature, it is still difficult to trace the pathway by which fetal events, environmental or not, may lead to the increased morbidity later in life. To explain this association, several hypotheses have been proposed pointing to the role of either a detrimental fetal environment or a genetic susceptibility or an interaction between the two and of the particular dynamic changes in adiposity that occur during catch-up growth. The relative impact of early postnatal events in relation to fetal growth has to be considered for designing health policy strategies for early interventions aimed at decreasing the diseases risk throughout life.

Long-lasting severe immune dysfunction in Ebola virus disease survivors.

Long-term follow up studies from Ebola virus disease (EVD) survivors (EBOV_S) are lacking. Here, we evaluate immune and gene expression profiles in 35 Guinean EBOV_S from the last West African outbreak, a median of 23 months (IQR [18-25]) after discharge from treatment center. Compared with healthy donors, EBOV_S exhibit increases of blood markers of inflammation, intestinal tissue damage, T cell and B cell activation and a depletion of circulating dendritic cells. All survivors have EBOV-specific IgG antibodies and robust and polyfunctional EBOV-specific memory T-cell responses. Deep sequencing of the genes expressed in blood reveals an enrichment in 'inflammation' and 'antiviral' pathways. Integrated analyses identify specific immune markers associated with the persistence of clinical symptoms. This study identifies a set of biological and genetic markers that could be used to define a signature of "chronic Ebola virus disease (CEVD)".

Feasibility of high-throughput sequencing in clinical routine cancer care: lessons from the cancer pilot project of the France Genomic Medicine 2025 plan.

BACKGROUND: Whole exome sequencing and RNA sequencing (WES/RNASeq) should now be implemented in the clinical practice in order to increase access to optimal care for cancer patients. Providing results to Tumour Boards in a relevant time frame-that is, compatible with the clinical pathway-is crucial. Assessing the feasibility of this implementation in the French care system is the primary objective of the Multipli study, as one of the four pilot projects of the national France Genomic Medicine 2025 (FGM 2025) plan. The Multipli study encompasses two innovative trials which will be driven in around 2400 patients suffering from a soft-tissue sarcoma (Multisarc) or a metastatic colorectal carcinoma (Acompli). METHODS: Prior to launching the FGM 2025 cancer pilot study itself, the performance of the Multipli genomic workflow has been evaluated through each step, from the samples collection to the Molecular Tumour Board (MTB) report. Two Multipli-assigned INCa-labelled molecular genetics centres, the CEA-CNRGH sequencing platform and the Institut Bergonié's Bioinformatics Platform were involved in a multicentric study. The duration of each step of the genomic workflow was monitored and bottlenecks were identified. RESULTS: Thirty barriers which could affect the quality of the samples, sequencing results and the duration of each step of the genomic pathway were identified and mastered. The global turnaround time from the sample reception to the MTB report was of 44 calendar days. CONCLUSION: Our results demonstrate the feasibility of tumour genomic analysis by WES/RNASeq within a time frame compatible with the current cancer patient care. Lessons learnt from the Multipli WES/RNASeq Platforms Workflow Study will constitute guidelines for the forthcoming Multipli study and more broadly for the future clinical routine practice in the first two France Genomic Medicine 2025 platforms.

Lassa fever clinical course and setting a standard of care for future randomized trials: A protocol for a cohort study of Lassa-infected patients in Nigeria (LASCOPE).

BACKGROUND: Lassa Fever (LF), is a severe viral disease prevalent in Western Africa. It is classified as a priority disease by the World Health Organization (WHO). Ribavirin is the recommended therapy despite weak evidence of its efficacy. Promising therapeutic agents are becoming available for evaluation in human. Before launching therapeutic trials, we need data on the evolution of the disease under the best possible conditions of care. METHODS: We have initiated a prospective study in Nigeria to better understand the clinical course and prognostic factors of LF while implementing high quality standardized care. Inclusion criteria are: suspected or confirmed LF and informed consent. Participants are followed 60 days from admission and receive free of charge standardized supportive care and biological monitoring, as well as intravenous ribavirin for those with confirmed LF. Data are collected using standardized case report forms (CRF). Primary and secondary outcomes are fatality and severe morbidity, with special focus on acute kidney dysfunction and pregnancy complications. Factors associated with outcomes will be investigated. RESULTS: The cohort is planned for 3 years. Inclusions started in April 2018 at the Federal Medical Center Owo in Ondo State. A second site will open in Nigeria in 2020 and discussions are underway to open a site in Benin. 150 to 200 new participants are expected per year. CONCLUSIONS: This cohort will: provide evidence to standardize LF case management; provide key inputs to design future clinical trials of novel therapeutics; and establish clinical research teams capable of conducting such trials in LF-endemic areas. STUDY REGISTRATION: The LASCOPE study was registered on ClinicalTrial.gov (NCT03655561).

Enrolling study personnel in Ebola vaccine trials: from guidelines to practice in a non-epidemic context.

BACKGROUND: Enrolling participants in clinical trials can be challenging, especially with respect to prophylactic vaccine trials. The vaccination of study personnel in Ebola vaccine trials during the 2014-2016 epidemic played a crucial role in inspiring trust and facilitating volunteer enrollment. We evaluated the ethical and methodological considerations as they applied to an ongoing phase 2 randomized prophylactic Ebola vaccine trial that enrolled healthy volunteers in Guinea, Liberia, Sierra Leone, and Mali in a non-epidemic context. METHODS: On the assumption that the personnel on site involved in executing the protocol, as well as community mobilizers (not involved in the on-site procedures), might also volunteer to enter the trial, we considered both ethical and methodological considerations to set clear rules that can be shared a priori with these persons. We reviewed the scientific and gray literature to identify relevant references and then conducted an analysis of the ethical and methodological considerations. RESULTS: There are currently no regulations preventing a clinical investigator or site staff from participating in a trial. However, the enrollment of personnel raises the risk of undue influence and challenges the basic ethical principle of voluntary participation. The confidentiality of personal medical information, such as HIV test results, may also be difficult to ensure among personnel. There is a risk of disruption of trial operations due to the potential absence of the personnel for their commitment as trial participants, and there is also a potential for introducing differential behavior of on-site staff as they obtain access to accumulating information during the trial (e.g., the incidence of adverse events). Blinding could be jeopardized, given knowledge of product-specific adverse event profiles and the proximity to unblinded site staff. These aspects were considered more relevant for on-site staff than for community mobilizers, who have limited contact with site staff. CONCLUSION: In a non-epidemic context, ethical and methodological considerations limit the collective benefit of enrolling site staff in a vaccine trial. These considerations do not apply to community mobilizers, whose potential enrollment should be considered as long as they meet the inclusion criteria and they are not exposed to any form of coercion.

Loss-of-function mutations in MRAP2 are pathogenic in hyperphagic obesity with hyperglycemia and hypertension.

The G-protein-coupled receptor accessory protein MRAP2 is implicated in energy control in rodents, notably via the melanocortin-4 receptor1. Although some MRAP2 mutations have been described in people with obesity1-3, their functional consequences on adiposity remain elusive. Using large-scale sequencing of MRAP2 in 9,418 people, we identified 23 rare heterozygous variants associated with increased obesity risk in both adults and children. Functional assessment of each variant shows that loss-of-function MRAP2 variants are pathogenic for monogenic hyperphagic obesity, hyperglycemia and hypertension. This contrasts with other monogenic forms of obesity characterized by excessive hunger, including melanocortin-4 receptor deficiency, that present with low blood pressure and normal glucose tolerance4. The pleiotropic metabolic effect of loss-of-function mutations in MRAP2 might be due to the failure of different MRAP2-regulated G-protein-coupled receptors in various tissues including pancreatic islets.

Consequences of being born small for gestational age on body composition: an 8-year follow-up study.

CONTEXT: Increased fat mass has been reported in children and adults born small for gestational age (SGA). However, the progression of anthropometric parameters have been poorly documented in SGA adults. OBJECTIVE: We hypothesized that SGA individuals would remain susceptible to gain more fat when adults beyond the period of postnatal catch-up growth. STUDY POPULATION AND DESIGN: From a community-based cohort, 389 subjects born full-term SGA (body weight < 10th percentile) were compared with 462 subjects born appropriate for gestational age (25th < body weight < 75th percentile). Anthropometric parameters were measured at 22 and 30 yr as well as body composition (by multifrequency bioelectrical impedancometry and skinfold thickness) at 30 yr. RESULTS: Both groups gained weight, body mass index (BMI), and waist circumference. Progression of BMI was significantly greater in SGA (1.8 +/- 2.6 vs. 1.4 +/- 2.6 kg/m(2); P = 0.03). At 30 yr, the proportion of obese individuals was significantly increased in SGA (12.1 vs. 6.5%; P = 0.02), and percent body fat was significantly higher (23.5 +/- 8.7 vs. 21.9 +/- 8.0%; P = 0.01), the observation of which was confirmed by skinfold measures. Similarly, waist circumference gain was significantly greater in SGA (6.4 +/- 7.6 vs. 5.5 +/- 7.9, P = 0.04 when adjusted for gender and age). CONCLUSION: Over 8-yr follow-up, adults born SGA gained more BMI than appropriate for gestational age, resulting in greater fat mass with more abdominal fat. These data suggest that the consequences of fetal growth restriction on body composition are evolving beyond the period of early postnatal catch-up.

Adaptive changes in neonatal hormonal and metabolic profiles induced by fetal growth restriction.

CONTEXT: Birth weight (BW) is usually taken as a surrogate of fetal growth. However, BW per se is not relevant enough in assessing fetal growth restriction, which by itself may alter body composition, metabolic, and hormonal profiles at birth (irrespective of BW), reflecting the necessary adaptive changes in metabolism under poor fetal environment. OBJECTIVE: Our objective was to measure body composition, hormonal, and metabolic parameters at birth in relation to both BW and fetal growth velocity. METHODS: A total of 235 pregnancies at risk of low BW were included, and newborns were observed at birth. Fetal growth velocity was calculated as the change in customized percentiles of estimated fetal weight between 22 wk gestational age and birth. Newborns were ranked in descending order of fetal growth velocity and divided in three equal tertiles. RESULTS: The lower fetal growth velocity tertile showed a severe fetal growth restriction (-52% +/- 21%) and was significantly associated with reduced lean and fat mass (P < 0.001 and 0.02, respectively). Insulin concentration was significantly related to fetal growth velocity (P = 0.006) and fat mass (P = 004) but not to BW (grams), whereas fetal growth velocity (P = 0.002) and BW (P < 0.001) but not fat mass had a significant effect on IGF-I concentration at birth. CONCLUSION: Fetal growth restriction induces changes in body composition and metabolism suggestive of a higher insulin sensitivity independently from BW itself, reflecting adaptive changes to an adverse fetal nutritional environment.

Pathophysiology of insulin resistance in subjects born small for gestational age.

Over the last 15 years, a number of long-term health risks associated with reduced fetal growth have been identified, including cardiovascular diseases, hypertension, dyslipidaemia and type 2 diabetes. A common feature of these conditions is insulin resistance, which is thought to play a pathogenic role. However, despite abundant data in the literature, it is still difficult to trace the pathway by which fetal events, environmental or not, may lead to increased morbidity later in life. To explain this association, several hypotheses have been proposed pointing to the role of a detrimental fetal environment, a genetic susceptibility or an interaction between the two, and of the particular dynamic changes in adiposity that occur during catch-up growth. The relative impact of early postnatal events in relation to fetal growth has to be considered for designing health policy strategies for early interventions aimed at decreasing disease risk throughout life.