Estimating heritability and its enrichment in tissue-specific gene sets in admixed populations.

It is important to study the genetics of complex traits in diverse populations. Here, we introduce covariate-adjusted linkage disequilibrium (LD) score regression (cov-LDSC), a method to estimate SNP-heritability (${\boldsymbol{h}}_{\boldsymbol{g}}^{\mathbf{2}})$ and its enrichment in homogenous and admixed populations with summary statistics and in-sample LD estimates. In-sample LD can be estimated from a subset of the genome-wide association studies samples, allowing our method to be applied efficiently to very large cohorts. In simulations, we show that unadjusted LDSC underestimates ${\boldsymbol{h}}_{\boldsymbol{g}}^{\mathbf{2}}$ by 10-60% in admixed populations; in contrast, cov-LDSC is robustly accurate. We apply cov-LDSC to genotyping data from 8124 individuals, mostly of admixed ancestry, from the Slim Initiative in Genomic Medicine for the Americas study, and to approximately 161 000 Latino-ancestry individuals, 47 000 African American-ancestry individuals and 135 000 European-ancestry individuals, as classified by 23andMe. We estimate ${\boldsymbol{h}}_{\boldsymbol{g}}^{\mathbf{2}}$ and detect heritability enrichment in three quantitative and five dichotomous phenotypes, making this, to our knowledge, the most comprehensive heritability-based analysis of admixed individuals to date. Most traits have high concordance of ${\boldsymbol{h}}_{\boldsymbol{g}}^{\mathbf{2}}$ and consistent tissue-specific heritability enrichment among different populations. However, for age at menarche, we observe population-specific heritability estimates of ${\boldsymbol{h}}_{\boldsymbol{g}}^{\mathbf{2}}$. We observe consistent patterns of tissue-specific heritability enrichment across populations; for example, in the limbic system for BMI, the per-standardized-annotation effect size $ \tau $* is 0.16 ± 0.04, 0.28 ± 0.11 and 0.18 ± 0.03 in the Latino-, African American- and European-ancestry populations, respectively. Our approach is a powerful way to analyze genetic data for complex traits from admixed populations.

miRNAs in cerebrospinal fluid identify patients with MS and specifically those with lipid-specific oligoclonal IgM bands.

BACKGROUND: MicroRNAs (miRNAs) are non-coding RNAs that regulate cellular processes by controlling protein translation and mRNA degradation. OBJECTIVE: We aimed to explore the miRNA signature of multiple sclerosis (MS) patients versus controls and the possibility that patients with lipid-specific oligolconal IgM bands (LS_OCMB), a predictor of a more severe disease course, may have a distinct profile. METHODS: An extensive profile of 754 miRNAs was evaluated in the cerebrospinal fluid (CSF) of 14 women using TaqMan low-density arrays. Differentially expressed miRNAs together with others previously identified in the literature were validated in an extended sample of 86 MS patients (39 LS_OCMB+) and 55 controls. RESULTS: We detected higher levels of miR-150 in MS patients and especially in those with LS_OCMB+. Other miRNAs (miR-328, miR-30a-5p and miR-645) were up-regulated in MS patients compared to controls while miR-21, miR-199a-3p, miR-191, miR-365, miR-106a and miR-146a showed down-regulated expression. Considering only patients with LS_OCMB+, we also detected up-regulation of miR-30a-5p, miR-150 and miR-645 and down-regulation of miR-191 compared to controls. CONCLUSION: Our study confirms the recent findings regarding the deregulated expression of miR-150 not only with MS but also with the presence of LS_OCMB. This study highlights the potential utility of miRNAs in CSF as biomarkers for MS.

Unravelling the hidden DNA structural/physical code provides novel insights on promoter location.

Although protein recognition of DNA motifs in promoter regions has been traditionally considered as a critical regulatory element in transcription, the location of promoters, and in particular transcription start sites (TSSs), still remains a challenge. Here we perform a comprehensive analysis of putative core promoter sequences relative to non-annotated predicted TSSs along the human genome, which were defined by distinct DNA physical properties implemented in our ProStar computational algorithm. A representative sampling of predicted regions was subjected to extensive experimental validation and analyses. Interestingly, the vast majority proved to be transcriptionally active despite the lack of specific sequence motifs, indicating that physical signaling is indeed able to detect promoter activity beyond conventional TSS prediction methods. Furthermore, highly active regions displayed typical chromatin features associated to promoters of housekeeping genes. Our results enable to redefine the promoter signatures and analyze the diversity, evolutionary conservation and dynamic regulation of human core promoters at large-scale. Moreover, the present study strongly supports the hypothesis of an ancient regulatory mechanism encoded by the intrinsic physical properties of the DNA that may contribute to the complexity of transcription regulation in the human genome.

Targeting the circulating microRNA signature of obesity.

BACKGROUND: Genomic studies have yielded important insights into the pathogenesis of obesity. Circulating microRNAs (miRNAs) are valuable biomarkers of systemic diseases and potential therapeutic targets. We sought to define the circulating pattern of miRNAs in obesity and examine changes after weight loss. METHODS: We assessed the genomewide circulating miRNA profile cross-sectionally in 32 men and after surgery-induced weight loss in 6 morbidly obese patients. The most relevant miRNAs were cross-sectionally validated in 80 men and longitudinally in 22 patients (after surgery-induced weight loss). We evaluated the effects of diet-induced weight loss in 9 obese patients. Thirty-six circulating miRNAs were associated with anthropometric variables in the initial sample. RESULTS: In the validation study, morbidly obese patients showed a marked increase of miR-140-5p, miR-142-3p (both P < 0.0001), and miR-222 (P = 0.0002) and decreased levels of miR-532-5p, miR-125b, miR-130b, miR-221, miR-15a, miR-423-5p, and miR-520c-3p (P < 0.0001 for all). Interestingly, in silico targets leukemia inhibitory factor receptor (LIFR) and transforming growth factor receptor (TGFR) of miR-140-5p, miR-142-3p, miR-15a, and miR-520c-3p circulated in association with their corresponding miRNAs. Moreover, a discriminant function of 3 miRNAs (miR-15a, miR-520c-3p, and miR-423-5p) was specific for morbid obesity, with an accuracy of 93.5%. Surgery-induced (but not diet-induced) weight loss led to a marked decrease of miR-140-5p, miR-122, miR-193a-5p, and miR-16-1 and upregulation of miR-221 and miR-199a-3p (P < 0.0001 for all). CONCLUSIONS: Circulating miRNAs are deregulated in severe obesity. Weight loss-induced changes in this profile and the study of in silico targets support this observation and suggest a potential mechanistic relevance.

ZNRD1 (zinc ribbon domain-containing 1) is a host cellular factor that influences HIV-1 replication and disease progression.

BACKGROUND: Human immunodeficiency virus (HIV) takes advantage of multiple host proteins to support its own replication. The gene ZNRD1 (zinc ribbon domain-containing 1) has been identified as encoding a potential host factor that influenced disease progression in HIV-positive individuals in a genomewide association study and also significantly affected HIV replication in a large-scale in vitro short interfering RNA (siRNA) screen. Genes and polymorphisms identified by large-scale analysis need to be followed up by means of functional assays and resequencing efforts to more precisely map causal genes. METHODS: Genotyping and ZNRD1 gene resequencing for 208 HIV-positive subjects (119 who experienced long-term nonprogression [LTNP] and 89 who experienced normal disease progression) was done by either TaqMan genotyping assays or direct sequencing. Genetic association analysis was performed with the SNPassoc package and Haploview software. siRNA and short hairpin RNA (shRNA) specifically targeting ZNRD1 were used to transiently or stably down-regulate ZNRD1 expression in both lymphoid and nonlymphoid cells. Cells were infected with X4 and R5 HIV strains, and efficiency of infection was assessed by reporter gene assay or p24 assay. RESULTS: Genetic association analysis found a strong statistically significant correlation with the LTNP phenotype (single-nucleotide polymorphism rs1048412; P = .0004), independently of HLA-A10 influence. siRNA-based functional analysis showed that ZNRD1 down-regulation by siRNA or shRNA impaired HIV-1 replication at the transcription level in both lymphoid and nonlymphoid cells. CONCLUSION: Genetic association analysis unequivocally identified ZNRD1 as an independent marker of LTNP to AIDS. Moreover, in vitro experiments pointed to viral transcription as the inhibited step. Thus, our data strongly suggest that ZNRD1 is a host cellular factor that influences HIV-1 replication and disease progression in HIV-positive individuals.

Association of NTRK3 and its interaction with NGF suggest an altered cross-regulation of the neurotrophin signaling pathway in eating disorders.

Eating disorders (EDs) are complex psychiatric diseases that include anorexia nervosa and bulimia nervosa, and have higher than 50% heritability. Previous studies have found association of BDNF and NTRK2 to ED, while animal models suggest that other neurotrophin genes might also be involved in eating behavior. We have performed a family-based association study with 151 TagSNPs covering 10 neurotrophin signaling genes: NGFB, BDNF, NTRK1, NGFR/p75, NTF4/5, NTRK2, NTF3, NTRK3, CNTF and CNTFR in 371 ED trios of Spanish, French and German origin. Besides several nominal associations, we found a strong significant association after correcting for multiple testing (P = 1.04 x 10(-4)) between ED and rs7180942, located in the NTRK3 gene, which followed an overdominant model of inheritance. Interestingly, HapMap unrelated individuals carrying the rs7180942 risk genotypes for ED showed higher levels of expression of NTRK3 in lymphoblastoid cell lines. Furthermore, higher expression of the orthologous murine Ntrk3 gene was also detected in the hypothalamus of the anx/anx mouse model of anorexia. Finally, variants in NGFB gene appear to modify the risk conferred by the NTRK3 rs7180942 risk genotypes (P = 4.0 x 10(-5)) showing a synergistic epistatic interaction. The reported data, in addition to the previous reported findings for BDNF and NTRK2, point neurotrophin signaling genes as key regulators of eating behavior and their altered cross-regulation as susceptibility factors for EDs.

Transferrin receptor-1 gene polymorphisms are associated with type 2 diabetes.

BACKGROUND: Iron is involved in oxidative stress and type 2 diabetes (T2D). Transferrin receptor (TFRC) constitutes the major receptor by which most cells take up iron. The aim of this study was to evaluate whether TFRC gene polymorphisms are associated with T2D. MATERIALS AND METHODS: We evaluated TFRC gene polymorphism (rs3817672, 210AG, S142G) in a sample of T2D patients and nondiabetic controls (n = 722), and 39 SNPs within the TFRC genomic region analysed by the Welcome Trust Case Control Consortium (WTCCC) (1921 T2D subjects and 3000 controls). In a subset of subjects, glucose tolerance and insulin sensitivity were also studied. RESULTS: The frequency of the G allele at the position 210 of the TFRC gene was significantly higher in T2D patients. Both GG and GA genotypes had a 69% (P < 0.01) greater risk of developing T2D estimated under a dominant model. The increased prevalence of the G allele run in parallel to increased sex-adjusted log-serum ferritin and slightly increased soluble transferrin receptor among patients with T2D. Furthermore, post-load glucose and insulin sensitivity were significantly associated with circulating soluble transferrin receptor, and insulin sensitivity was significantly associated with serum ferritin among G allele carriers, (r = -0.33, P = 0.001) but not in AA homozygotes. Sixteen other TFRC SNPs were also associated to T2D according to the Welcome Trust Case Control Consortium data. CONCLUSION: TFRC gene variants are associated with T2D.

Discovering metabolic disease gene interactions by correlated effects on cellular morphology.

OBJECTIVE: Impaired expansion of peripheral fat contributes to the pathogenesis of insulin resistance and Type 2 Diabetes (T2D). We aimed to identify novel disease-gene interactions during adipocyte differentiation. METHODS: Genes in disease-associated loci for T2D, adiposity and insulin resistance were ranked according to expression in human adipocytes. The top 125 genes were ablated in human pre-adipocytes via CRISPR/CAS9 and the resulting cellular phenotypes quantified during adipocyte differentiation with high-content microscopy and automated image analysis. Morphometric measurements were extracted from all images and used to construct morphologic profiles for each gene. RESULTS: Over 107 morphometric measurements were obtained. Clustering of the morphologic profiles accross all genes revealed a group of 14 genes characterized by decreased lipid accumulation, and enriched for known lipodystrophy genes. For two lipodystrophy genes, BSCL2 and AGPAT2, sub-clusters with PLIN1 and CEBPA identifed by morphological similarity were validated by independent experiments as novel protein-protein and gene regulatory interactions. CONCLUSIONS: A morphometric approach in adipocytes can resolve multiple cellular mechanisms for metabolic disease loci; this approach enables mechanistic interrogation of the hundreds of metabolic disease loci whose function still remains unknown.

Hypothalamus transcriptome profile suggests an anorexia-cachexia syndrome in the anx/anx mouse model.

The anx/anx mouse displays poor appetite and lean appearance and is considered a good model for the study of anorexia nervosa. To identify new genes involved in feeding behavior and body weight regulation we performed an expression profiling in the hypothalamus of the anx/anx mice. Using commercial microarrays we detected 156 differentially expressed genes and validated 92 of those using TaqMan low-density arrays. The expression of a set of 87 candidate genes selected based on literature evidences was also quantified by TaqMan low-density arrays. Our results showed enrichment in deregulated genes involved in cell death, cell morphology, and cancer, as well as an alteration of several signaling circuits involved in energy balance including neuropeptide Y and melanocortin signaling. The expression profile along with the phenotype led us to conclude that anx/anx mice resemble the anorexia-cachexia syndrome typically observed in cancer, infection with human immunodeficiency virus or chronic diseases, rather than starvation, and that anx/anx mice could be considered a good model for the treatment and investigation of this condition.

Patterns of cerebral white matter damage and cognitive impairment in adolescents born very preterm.

There is increasing evidence about the presence of white matter damage in subjects with a history of premature birth, even in those classified as good outcome because of an apparently normal development. Although intellectual performance is within normal limits in premature children it is significantly decreased compared to paired controls. The purpose of this study was to investigate the relationship between a lower performance intelligence quotient and white matter damage in preterm adolescents. The sample comprised 44 adolescents (mean age+/-S.D.: 14.4+/-1.6 years) born before 32 weeks of gestational age and 43 term-born adolescents (14.5+/-2.1 years). Individual voxel-based morphometry analyses demonstrated that 35/44 (80%) preterm subjects had white matter abnormalities. The centrum semiovale and the posterior periventricular regions were the most frequently affected areas. Correlation analysis showed that in preterms the performance intelligence quotient correlated with the whole-brain white matter volume (r=0.32; P=0.036) but not with grey matter volume. Complementary analysis showed that low scores in the Digit Symbol subtest, a measure of processing speed, in the preterm group correlated with reductions in white matter concentration. These results suggest that white matter damage is highly common and that it persists until adolescence. Hence, diffuse white matter loss may be responsible for performance intelligence quotient and processing speed decrements in subjects with very preterm birth.

Proton magnetic resonance spectroscopy reveals medial temporal metabolic abnormalities in adolescents with history of preterm birth.

Prematurity is associated with volumetric reductions in specific brain areas such as the hippocampus and with metabolic changes that can be detected by spectroscopy. Short echo time (35 ms) Proton magnetic resonance spectroscopy (1H MRS) was performed to assess possible medial temporal lobe metabolic abnormalities in 21 adolescents with preterm birth (mean age: 14.8, SD: 1.3) compared with an age-matched control sample (mean age: 14.8, SD: 1.6). 1H MRS spectra were analyzed with linear combination model fitting, obtaining the absolute metabolite concentrations for Creatine (Cr), and myo-inositol (Ins). In addition, the following metabolite sums were measured: total Cho (glycerophospho-choline + phosphocholine), total N-acetyl-aspartate + N-acetyl-aspartylglutamate (NA), and total Glx (glutamate + glutamine). A stereological analysis was performed to calculate hippocampal volume. Absolute Cr, and total NA values were decreased in the preterm group (p = 0.016; p = 0.002, respectively). The preterm also showed a hippocampal reduction (p < 0.0001). Significant relationships were found between gestational age and different metabolites and the hippocampal volume. Moreover, hippocampal volume correlated with brain metabolites in the whole sample. Results demonstrate that prematurity affects medial temporal lobe metabolites, and that the alteration is related to structural changes, suggesting that the cerebral changes persist until adolescence.

Genomic profiling in advanced stage non-small-cell lung cancer patients with platinum-based chemotherapy identifies germline variants with prognostic value in SMYD2.

OBJECTIVE: The aim of the study was to investigate the relationship between germline variations as a prognosis biomarker in patients with advanced Non-Small-Cell-Lung-Cancer (NSCLC) subjected to first-line platinum-based treatment. MATERIALS AND METHODS: We carried out a two-stage genome-wide-association study in non-small-cell lung cancer patients with platinum-based chemotherapy in an exploratory sample of 181 NSCLC patients from Caucasian origin, followed by a validation on 356 NSCLC patients from the same ancestry (Valencia, Spain). RESULTS: We identified germline variants in SMYD2 as a prognostic factor for survival in patients with advanced NSCLC receiving chemotherapy. SMYD2 alleles are associated to a decreased overall survival and with a reduced Time to Progression. In addition, enrichment pathway analysis identified 361 variants in 40 genes to be involved in poorer outcome in advanced-stage NSCLC patients. CONCLUSION: Germline SMYD2 alleles are associated with bad clinical outcome of first-line platinum-based treatment in advanced NSCLC patients. This result supports the role of SMYD2 in the carcinogenic process, and might be used as prognostic signature directing patient stratification and the choice of therapy. MICROABSTRACT: A two-Stage Genome wide association study in Caucasian population reveals germline genetic variation in SMYD2 associated to progression disease in first-line platinum-based treatment in advanced NSCLC patients. SMYD2 profiling might have prognostic / predictive value directing choice of therapy and enlighten current knowledge on pathways involved in human carcinogenesis as well in resistance to chemotherapy.

Publisher Correction: Re-analysis of public genetic data reveals a rare X-chromosomal variant associated with type 2 diabetes.

In the originally published version of this Article, the affiliation details for Santi González, Jian'an Luan and Claudia Langenberg were inadvertently omitted. Santi González should have been affiliated with 'Barcelona Supercomputing Center (BSC), Joint BSC-CRG-IRB Research Program in Computational Biology, 08034 Barcelona, Spain', and Jian'an Luan and Claudia Langenberg should have been affiliated with 'MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK'. Furthermore, the abstract contained an error in the SNP ID for the rare variant in chromosome Xq23, which was incorrectly given as rs146662057 and should have been rs146662075. These errors have now been corrected in both the PDF and HTML versions of the Article.

Re-analysis of public genetic data reveals a rare X-chromosomal variant associated with type 2 diabetes.

The reanalysis of existing GWAS data represents a powerful and cost-effective opportunity to gain insights into the genetics of complex diseases. By reanalyzing publicly available type 2 diabetes (T2D) genome-wide association studies (GWAS) data for 70,127 subjects, we identify seven novel associated regions, five driven by common variants (LYPLAL1, NEUROG3, CAMKK2, ABO, and GIP genes), one by a low-frequency (EHMT2), and one driven by a rare variant in chromosome Xq23, rs146662057, associated with a twofold increased risk for T2D in males. rs146662057 is located within an active enhancer associated with the expression of Angiotensin II Receptor type 2 gene (AGTR2), a modulator of insulin sensitivity, and exhibits allelic specific activity in muscle cells. Beyond providing insights into the genetics and pathophysiology of T2D, these results also underscore the value of reanalyzing publicly available data using novel genetic resources and analytical approaches.

MRPS18CP2 alleles and DEFA3 absence as putative chromosome 8p23.1 modifiers of hearing loss due to mtDNA mutation A1555G in the 12S rRNA gene.

BACKGROUND: Mitochondrial DNA (mtDNA) mutations account for at least 5% of cases of postlingual, nonsyndromic hearing impairment. Among them, mutation A1555G is frequently found associated with aminoglycoside-induced and/or nonsyndromic hearing loss in families presenting with extremely variable clinical phenotypes. Biochemical and genetic data have suggested that nuclear background is the main factor involved in modulating the phenotypic expression of mutation A1555G. However, although a major nuclear modifying locus was located on chromosome 8p23.1 and regardless intensive screening of the region, the gene involved has not been identified. METHODS: With the aim to gain insights into the factors that determine the phenotypic expression of A1555G mutation, we have analysed in detail different genetic and genomic elements on 8p23.1 region (DEFA3 gene absence, CLDN23 gene and MRPS18CP2 pseudogene) in a group of 213 A1555G carriers. RESULTS: Family based association studies identified a positive association for a polymorphism on MRPS18CP2 and an overrepresentation of DEFA3 gene absence in the deaf group of A1555G carriers. CONCLUSION: Although none of the factors analysed seem to have a major contribution to the phenotype, our findings provide further evidences of the involvement of 8p23.1 region as a modifying locus for A1555G 12S rRNA gene mutation.

Dysregulation of Placental miRNA in Maternal Obesity Is Associated With Pre- and Postnatal Growth.

Context: Human placenta exhibits a specific microRNA (miRNA) expression pattern. Some of these miRNAs are dysregulated in pregnancy disorders such as preeclampsia and intrauterine growth restriction and are potential biomarkers for these pathologies. Objective: To study the placental miRNA profile in pregnant women with pregestational overweight/obesity (preOB) or gestational obesity (gestOB) and explore the associations between placental miRNAs dysregulated in maternal obesity and prenatal and postnatal growth. Methods: TaqMan Low Density Arrays and real-time polymerase chain reaction were used to profile the placental miRNAs in 70 pregnant women (20 preOB, 25 gestOB, and 25 control). Placentas and newborns were weighed at delivery, and infants were weighed at 1, 4, and 12 months of age. Results: Eight miRNAs were decreased in placentas from preOB or gestOB (miR-100, miR-1269, miR-1285, miR-181, miR-185, miR-214, miR-296, and miR-487) (all P < 0.05). Among them, miR-100, miR-1285, miR-296, and miR-487 were associated with maternal metabolic parameters (all P < 0.05) and were predictors of lower birth weight (all P < 0.05; R2 > 30%) and increased postnatal weight gain (all P < 0.05; R2 > 20%). In silico analysis showed that these miRNAs were related to cell proliferation and insulin signaling pathways. miR-296 was also present in plasma samples and associated with placental expression and prenatal and postnatal growth parameters (all P < 0.05). Conclusions: We identified a specific placental miRNA profile in maternal obesity. Placental miRNAs dysregulated in maternal obesity may be involved in mediation of growth-promoting effects of maternal obesity on offspring and could be used as early markers of prenatal and postnatal growth.

Correlations of thalamic reductions with verbal fluency impairment in those born prematurely.

Prematurity is associated with reduced brain volume, and the thalamus is among the structures most affected. We used a voxel-based morphometry analysis of gray matter to map regional atrophy in the thalamus in a sample of 30 adolescents with antecedents of very preterm birth. The preterm sample was compared with 30 controls matched by age, sex, handedness and sociocultural status. Individuals with very preterm birth differed from controls in several thalamic nuclei, and semantic and phonetic fluency showed different correlation patterns with brain volume. Semantic fluency achieved significant correlations with more thalamic nuclei than phonetic fluency. These results agree with functional magnetic resonance imaging studies showing that semantic fluency involves more cerebral regions than phonetic fluency.

MR imaging of temporomandibular joint dysfunction: a pictorial review.

Temporomandibular joint (TMJ) dysfunction is a common condition that is best evaluated with magnetic resonance (MR) imaging. The first step in MR imaging of the TMJ is to evaluate the articular disk, or meniscus, in terms of its morphologic features and its location relative to the condyle in both closed- and open-mouth positions. Disk location is of prime importance because the presence of a displaced disk is a critical sign of TMJ dysfunction. However, disk displacement is also frequently seen in asymptomatic volunteers, so that other findings may be required to help make the diagnosis. These findings include thickening of an attachment of the lateral pterygoid muscle, rupture of retrodiskal layers, and joint effusion and can serve as indirect early signs of TMJ dysfunction. It is important for the radiologist to detect early MR imaging signs of dysfunction, thereby avoiding the evolution of this condition to its final stage, an advanced and irreversible phase that is characterized by osteoarthritic changes such as condylar flattening or osteophytes. Further studies conducted with the latest MR imaging techniques will allow a better understanding of the sources of TMJ pain and of any discrepancy between imaging findings and patient symptoms.

Inflammation triggers specific microRNA profiles in human adipocytes and macrophages and in their supernatants.

BACKGROUND: The relevance of microRNAs (miRNAs) in adipose tissue is increasingly recognized, being intrinsically linked to different pathways, including obesity-related inflammation. In this study, we aimed to characterize the changes induced by inflammation on the miRNA pattern of human adipocytes and macrophages. Therefore, an extensive profile of 754 common miRNAs was assessed in cells (human primary mature adipocytes, and the macrophage-like cell line THP-1) and in their supernatants (SN) using TaqMan low-density arrays. These profiles were evaluated at the baseline and after administration of lipopolysaccharide (LPS, 10 ng/ml) and LPS-conditioned medium from M1 macrophages (MCM, 5%). The miRNAs that experienced the most dramatic changes were studied in subcutaneous human adipose tissue before and approximately 2 years after bariatric surgery-induced weight loss. RESULTS: Differentiated adipocytes expressed 169 miRNAs, being 85 detectable in the SN. In M1 macrophages, 183 miRNAs were detected, being 106 also present in the SN. Inflammation led to an increased number of miRNAs detectable in cells and in their SNs in both adipocytes (+8.3% and +24.7%) and M1 macrophages (+1.4% and +5%, respectively). Indeed, under inflammatory conditions, adipocytes and M1 macrophages shared the expression of 147 (+9%) miRNAs, and 100 (+41%) common miRNAs were found in their SNs. Twelve of these factors were also linked to inflammation in whole adipose tissue from obese subjects. Interestingly, miR-221 (2-fold, P = 0.002), miR-222 (2.5-fold, P = 0.04), and miR-155 (5-fold, P = 0.015) were increased in inflamed adipocytes and in their SNs (15-, 6-, and 4-fold, respectively, all P < 0.001). Furthermore, their expressions in human adipose tissue concordantly decreased after weight loss (-51%, P = 0.003, -49%, P = 0.03, and -54.4%, P = 0.005, respectively). CONCLUSIONS: Inflammation induces a specific miRNA pattern in adipocytes and M1 macrophages, with impact on the physiopathology of obesity-induced inflammation of adipose tissue. The crosstalk between cells should be investigated further.

Altered Circulating miRNA Expression Profile in Pregestational and Gestational Obesity.

CONTEXT: MicroRNAs (miRNAs) are valuable circulating biomarkers and therapeutic targets for metabolic diseases. OBJECTIVE: The objective of the study was to define the pattern of circulating miRNAs in pregestational and gestational obesity and to explore their associations with maternal metabolic parameters and with markers for pre- and postnatal growth. design, settings, and main outcome measure: TaqMan low-density arrays were used to profile plasma miRNAs in six women with pregestational obesity (PregestOB), six with gestational obesity (GestOB), and six with normal pregnancies (control) during the second trimester of gestation. The most relevant miRNAs were validated in 70 pregnant women (20 PregestOB, 25 GestOB, and 25 control). Maternal metabolic parameters including glucose, glycated hemoglobin, homeostasis model assessment index of insulin resistance, C-peptide, and lipids were assessed. Placentas were weighed at delivery and newborns also during 6 months of life. RESULTS: We identified 13 circulating miRNAs differentially expressed in maternal obesity, including decreased levels of miR-29c, miR-99b, miR-103, miR-221, and miR-340 and increased levels of miR-30a-5p, miR-130a, and miR-150 in GestOB; and decreased levels of miR-122, miR-324-3p, miR-375, and miR-652 and increased levels of miR-625 in both PregestOB and GestOB (P < .05 to P < .0001 vs control). Decreased levels of several of these miRNAs associated with a more adverse maternal metabolic status (more pregnancy weight gain, glucose, glycated hemoglobin, homeostasis model assessment index of insulin resistance, C-peptide, and triacylglycerol and less high density lipoprotein cholesterol), with more placental weight, weight at birth, and weight at 6 months of life (all P < .05 to P < .001). CONCLUSIONS: This study provides the first identification of altered circulating miRNAs in maternal obesity and suggests a possible role of such miRNAS as markers for pre- and postnatal growth.