Project description:Analysis of rectus femoris samples from chidren with obesity and normal weight. Obese children display insulin resistance (IR) and other metabolic abnormalities at higher rates than do normal weight children. Results provide insight into the molecular mechanisms underlying the pathogenesis of childhood obesity.
Project description:Epigenetics presents a dynamic approach to assess complex individual variation in obesity susceptibility. However, few studies have examined epigenetic patterns in preschool-age children, despite the relevance of this developmental stage to trajectories of weight gain, because of difficulties obtaining blood tissue samples. This proof of principle study examined DNA methylation in 92 saliva samples, comparing Latino preschool children of normal weight mothers (Body Mass Index [BMI] <27 kg/m2 and WC <90 cm) to children of obese mothers (BMI >30 kg/m2 and WC >100 cm). We hypothesized that salivary DNA methylation patterns in Latino preschool age children born of normal weight vs obese weight mothers would be: 1) associated with maternal BMI phenotype in continuous linear regression analysis; 2) saliva could demonstrate epigenetic variation across individuals; and 3) preschool child saliva would be differentially methylated when comparing those children with obese versus normal weight mothers. One hundred and nineteen CpG sites were significantly (p-value <1.56 X 10-5, p-value adjusted <.05) associated with maternal BMI in linear regression models controlling for child’s age, gender, and BMI. Of these 119 CpG sites, 41 were found within the transcription start site, 5’ UTR, 3’ UTR, or another regulatory region outside of the gene body. Saliva, a practical human tissue to obtain in naturalistic settings and in pediatric populations, was confirmed to be a viable medium for genome-wide epigenetic testing with maternal weight. Although not identical to results yielded from other human tissue types (i.e., cord blood samples), saliva findings indicate potential epigenetic differences in Latino preschool children at risk for pediatric obesity.
Project description:Epigenetics presents a dynamic approach to assess complex individual variation in obesity susceptibility. However, few studies have examined epigenetic patterns in preschool-age children, despite the relevance of this developmental stage to trajectories of weight gain, because of difficulties obtaining blood tissue samples. This proof of principle study examined DNA methylation in 92 saliva samples, comparing Latino preschool children of normal weight mothers (Body Mass Index [BMI] <27 kg/m2 and WC <90 cm) to children of obese mothers (BMI >30 kg/m2 and WC >100 cm). We hypothesized that salivary DNA methylation patterns in Latino preschool age children born of normal weight vs obese weight mothers would be: 1) associated with maternal BMI phenotype in continuous linear regression analysis; 2) saliva could demonstrate epigenetic variation across individuals; and 3) preschool child saliva would be differentially methylated when comparing those children with obese versus normal weight mothers. One hundred and nineteen CpG sites were significantly (p-value <1.56 X 10-5, p-value adjusted <.05) associated with maternal BMI in linear regression models controlling for childâs age, gender, and BMI. Of these 119 CpG sites, 41 were found within the transcription start site, 5â UTR, 3â UTR, or another regulatory region outside of the gene body. Saliva, a practical human tissue to obtain in naturalistic settings and in pediatric populations, was confirmed to be a viable medium for genome-wide epigenetic testing with maternal weight. Although not identical to results yielded from other human tissue types (i.e., cord blood samples), saliva findings indicate potential epigenetic differences in Latino preschool children at risk for pediatric obesity. This proof of principle study examined DNA methylation in 92 saliva samples, comparing Latino preschool children of normal weight mothers (Body Mass Index [BMI] <27 kg/m2 and WC <90 cm) to children of obese mothers (BMI >30 kg/m2 and WC >100 cm). Antropometry was measured objectively according to a standardized protocol.Saliva from preschool Latino children at risk for obesity (BMI>50% < 95% participating in WIC/SNAP programs) was collected using the Oragene DNA saliva kit following a strict data collection protocol. DNA extraction was performed as per DNA Genotek's recommendations using the PrepIT L2P reagent. Extracted DNA was stored in individually barcoded cryovials at â80 degrees Fahrenheit. For children, saliva was obtained using the âbaby brushâ approach, in which small sponges attached to plastic handles are inserted between cheek and gumline to absorb saliva .Arrays were processed using standard protocol [34], with 3 samples randomly selected to serve as duplicates and 1 sample run with HapMap DNA to test functionality of reagents. Duplicates were measured for high technique consistency with Pearson correlation coefficient (>.99). Methylation data were quality controlled using Illumina GenomeStudio (V2011.1), Methylation module (V1.9.0). Samples with lower than 98% call rate (i.e. <485,000 probes) were excluded. Any non-specific cross-reacting probes, probes carrying common SNPs (MAF >1%), or any probes with p-values greater than 0.05 for more than 20% of the sample were sequentially excluded. Validation via pyrosequencing was conducted.
Project description:Characterization of genes associated with adipose tissue is key to understanding the pathogenesis of obesity and developing treatments for this disorder. Differential gene expression in the adipose tissue has been described in adulthood but none studies have been developed on childhood. The purpose of this study was to compare gene expression in omental adipose tissue from obese prepubertal and normal weight children. We selected 5 obese (BMI adjusted for age and sex z score >2) and 6 normal weight children. RNA was extracted from omental adipose tissue biopsies and cRNA was hybridizated on the human genome U133 Plus 2.0 Arrays (Affymetrix®). Microarray experiments were performed for each sample, and selected group of gene expression values were confirmed with real-time RT-PCR in 10 obese and 10 normal weigth prepubertal children. 1276 genes were found to be differentially expressed at P<0.05. Of those differential genes, 201 were upregulated (Fc>2) and 42 were downregulated (Fc<-2). Genes involved in metabolic and signalling pathways were altered in childhood obesity. Keywords: disease state analysis
Project description:Most individuals do not maintain weight loss, and weight regain increases cardio-metabolic risk beyond that of obesity. Adipose inflammation directly contributes to insulin resistance; however, immune-related changes that occur with weight loss and weight regain are not well understood. Single cell RNA-sequencing was completed with CITE-sequencing and biological replicates to profile changes in murine immune subpopulations following obesity, weight loss, and weight cycling. Weight loss normalized glucose tolerance, however, type 2 immune cells did not repopulate adipose following weight loss. Many inflammatory populations persisted with weight loss and increased further following weight regain. Obesity drove T cell exhaustion and broad increases in antigen presentation, lipid handing, and inflammation that persisted with weight loss and weight cycling. This work provides critical groundwork for understanding the immunological causes of weight cycling-accelerated metabolic disease.
Project description:Characterization of genes associated with adipose tissue is key to understanding the pathogenesis of obesity and developing treatments for this disorder. Differential gene expression in the adipose tissue has been described in adulthood but none studies have been developed on childhood. The purpose of this study was to compare gene expression in omental adipose tissue from obese prepubertal and normal weight children. We selected 5 obese (BMI adjusted for age and sex z score >2) and 6 normal weight children. RNA was extracted from omental adipose tissue biopsies and cRNA was hybridizated on the human genome U133 Plus 2.0 Arrays (Affymetrix®). Microarray experiments were performed for each sample, and selected group of gene expression values were confirmed with real-time RT-PCR in 10 obese and 10 normal weigth prepubertal children. 1276 genes were found to be differentially expressed at P<0.05. Of those differential genes, 201 were upregulated (Fc>2) and 42 were downregulated (Fc<-2). Genes involved in metabolic and signalling pathways were altered in childhood obesity. Experiment Overall Design: Adipose tissue and blood samples were obtained from 27 children, 14 obese (BMI adjusted for age and sex z score > 2) and 13 non obese undergoing appendix surgery. About 400 mg of adipose tissue was taken and immediately immersed in RNAlater solution and stored at -80°C for gene expression analysis. Informed consent was obtained from all patients after the nature of the study was explained, and the experimental design was approved, from an ethical and scientific standpoint, by the Hospitalâs Ethical Committee responsible for research.
Project description:Pediatric obesity prevalence is rapidly rising worldwide and “omic” approaches are helpful in obesity molecular pathophysiology investigation. This work aimed at the identification of transcriptional differences in subcutaneous adipose tissue (scAT) of children with overweight (OW), obesity (OB) or severe obesity (SV) respect those with normal weight (NW). Periumbilical scAT biopsies were collected from 20 male children aged 1-12 years. Considering BMI z-score, chil-dren were stratified into 4 groups: SV, OB, OW, NW. scAT RNA-Seq analyses were performed, differential expression analysis was achieved using the DESeq2 R package. Pathways analysis was performed to gain biological insights on gene expression. Our data highlight the significant deregulation in both coding and non-coding transcripts in the SV group when compared to NW, OW, and OB. KEGG pathway analysis showed involvement for coding transcripts mainly in li-pid metabolism. GSEA analysis revealed upregulation of lipid degradation and metabolism in SV vs OB and SV vs OW. Bioenergetic processes and the catabolism of branched-chain amino acids resulted upregulated in SV when compared to OB, OW, NW. In conclusion, we report for the first time that a significant transcriptional deregulation occurs in periumbilical scAT of children with severe obesity with respect to normal weight, overweight or mild obesity.
Project description:Genome wide DNA methylation profiling of peripheral blood samples from 41 children with simple obesity and 31 normal controls. The Illumina Infinium MethylationEPIC BeadChip (Illumina 850k, San Diego, CA) was used to obtain DNA methylation profiles across greater than 850,000 CpG sites across the genome. Samples included 31 normal and 41 obesity peripheral blood.