Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood1. Previous genome-wide association studies identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes, and a second variant, near CCNL1, with no obvious link to adult traits2. In an expanded genome-wide association meta-analysis and follow-up study (up to 69,308 individuals of European descent from 43 studies), we have now extended the number of genome-wide significant loci to seven, accounting for a similar proportion of variance to maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes; ADRB1 with adult blood pressure; and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism.
The prevalence of obesity in children and adults in the United States has increased dramatically over the past decade. Besides environmental factors, genetic factors are known to play an important role in the pathogenesis of obesity. A number of genetic determinants of adult BMI have already been established through genome‐wide association (GWA) studies. In this study, we examined 25 single‐nucleotide polymorphisms (SNPs) corresponding to 13 previously reported genomic loci in 6,078 children with measures of BMI. Fifteen of these SNPs yielded at least nominally significant association to BMI, representing nine different loci including INSIG2, FTO, MC4R, TMEM18, GNPDA2, NEGR1, BDNF, KCTD15, and 1q25. Other loci revealed no evidence for association, namely at MTCH2, SH2B1, 12q13, and 3q27. For the 15 associated variants, the genotype score explained 1.12% of the total variation for BMI z‐score. We conclude that among 13 loci that have been reported to associate with adult BMI, at least nine also contribute to the determination of BMI in childhood as demonstrated by their associations in our pediatric cohort.
• Using AML as a model, we investigated the effect of treatment and disease evolution on functionally defined cancer stem cell populations.• We demonstrate large-scale changes in LSC frequency and phenotype after relapse, best described using highdimensional space analyses.Most cancers evolve over time as patients initially responsive to therapy acquire resistance to the same drugs at relapse. Cancer stem cells have been postulated to represent a therapy-refractory reservoir for relapse, but formal proof of this model is lacking. We prospectively characterized leukemia stem cell populations (LSCs) from a well-defined cohort of patients with acute myelogenous leukemia (AML) at diagnosis and relapse to assess the effect of the disease course on these critical populations. Leukemic samples were collected from patients with newly diagnosed AML before therapy and after relapse, and LSC frequency was assessed by limiting dilution analyses. LSC populations were identified using fluorescent-labeled cell sorting and transplantation into immunodeficient NOD/SCID/interleukin 2 receptor g chain null mice. The surface antigen expression profiles of pretherapy and postrelapse LSCs were determined for published LSC markers. We demonstrate a 9-to 90-fold increase in LSC frequency between diagnosis and relapse. LSC activity at relapse was identified in populations of leukemic blasts that did not demonstrate this activity before treatment and relapse. In addition, we describe genetic instability and exceptional phenotypic changes that accompany the evolution of these new LSC populations. This study is the first to characterize the evolution of LSCs in vivo after chemotherapy, identifying a dramatic change in the physiology of primitive AML cells when the disease progresses. Taken together, these findings provide a new frame of reference by which to evaluate candidate AML therapies in which both disease control and the induction of more advanced forms of disease should be considered. (Blood. 2016;128(13):1671-1678
The prevalence of obesity in children and adults in the United States has increased dramatically over the past decade. Genomic copy number variations (CNVs) have been strongly implicated in subjects with extreme obesity and coexisting developmental delay. To complement these previous studies, we addressed CNVs in common childhood obesity by examining children with a BMI in the upper 5(th) percentile but excluding any subject greater than three standard deviations from the mean in order to reduce severe cases in the cohort. We performed a whole-genome CNV survey of our cohort of 1080 defined European American (EA) childhood obesity cases and 2500 lean controls (< 50(th) percentile BMI) who were genotyped with 550,000 SNP markers. Positive findings were evaluated in an independent African American (AA) cohort of 1479 childhood obesity cases and 1575 lean controls. We identified 17 CNV loci that were unique to at least three EA cases and were both previously unreported in the public domain and validated via quantitative PCR. Eight of these loci (47.1%) also replicated exclusively in AA cases (six deletions and two duplications). Replicated deletion loci consisted of EDIL3, S1PR5, FOXP2, TBCA, ABCB5, and ZPLD1, whereas replicated duplication loci consisted of KIF2B and ARL15. We also observed evidence for a deletion at the EPHA6-UNQ6114 locus when the AA cohort was investigated as a discovery set. Although these variants may be individually rare, our results indicate that CNVs contribute to the genetic susceptibility of common childhood obesity in subjects of both European and African ancestry.
Obesity is a serious health concern for children and adolescents, particularly in Western societies, where its incidence is now considered to have reached epidemic proportions. A number of genetic determinants of adult BMI have already been established through genome wide association studies (GWAS), most recently from the GIANT meta‐analysis of such datasets combined. In this current study of European Americans, we examined the 32 loci detected in that GIANT study in the context of common childhood obesity within a cohort of 1,097 cases (defined as BMI ≥95th percentile), together with 2,760 lean controls (defined as BMI <50th percentile), aged between 2 and 18 years old. Nine of these single‐nucleotide polymorphims (SNPs) yielded at least nominal evidence for association with common childhood obesity, namely at the FTO, TMEM18, NRXN3, MC4R, SEC16B, GNPDA2, TNNI3K, QPCTL, and BDNF loci. However, overall 28 of the 32 loci showed directionally consistent effects to that of the adult BMI meta‐analysis. We conclude that among the 32 loci that have been reported to associate with adult BMI in the largest meta‐analysis of BMI to date, at least nine also contribute to the determination of common obesity in childhood in European Americans, as demonstrated by their associations in our pediatric cohort.
Scope: Gut barrier dysfunction and inflammation originating from a dysbiotic gut microbiota (GM) are strongly associated with a high-fat diet (HFD). Anthocyanins from Lycium ruthenicum (ACs) show antiobesity effects through modulating the GM. However, the mechanism linking the antiobesity effects of ACs and GM modulation remains obscure. Methods and results: To investigate the ameliorative effects of ACs on colonic barrier dysfunction and inflammation, mice are fed an HFD with or without ACs at doses of 50, 100, and 200 mg kg −1 for 12 weeks. AC supplementation reduced weight gain, enriched short-chain fatty acid (SCFA)-producing bacteria (e.g., Ruminococcaceae, Muribaculaceae, Akkermansia, Ruminococcaceae_UCG-014, and Bacteroides) and SCFA content, depleted endotoxin-producing bacteria (e.g., Helicobacter and Desulfovibrionaceae), and decreased endotoxin (i.e., lipopolysaccharide) levels. SCFAs substantially activated G protein-coupled receptors (GPRs), inhibited histone deacetylases (HDAC), increased intestinal tight junction mRNA and protein expression levels, reduced intestinal permeability, and protected intestinal barrier integrity in HFD-induced mice. These effects mitigate intestinal inflammation by inhibiting the LPS/NF-B/TLR4 pathway. Conclusion: These data indicates that ACs can mitigate colonic barrier dysfunction and inflammation, induce SCFA production and inhibit endotoxin production by modulating the GM in HFD-fed mice. This finding provides a clue for understanding the antiobesity effects of ACs.
The oral microbiota is associated with oral diseases and digestive systemic diseases. Nevertheless, the causal relationship between them has not been completely elucidated, and colonisation of the gut by oral bacteria is not clear due to the limitations of existing research models. The aim of this study was to develop a human oral microbiota-associated (HOMA) mouse model and to investigate the ecological invasion into the gut. By transplanting human saliva into germ-free (GF) mice, a HOMA mouse model was first constructed. 16S rRNA gene sequencing was used to reveal the biogeography of oral bacteria along the cephalocaudal axis of the digestive tract. In the HOMA mice, 84.78% of the detected genus-level taxa were specific to the donor. Principal component analysis (PCA) revealed that the donor oral microbiota clustered with those of the HOMA mice and were distinct from those of specific pathogen-free (SPF) mice. In HOMA mice, OTU counts decreased from the stomach and small intestine to the distal gut. The distal gut was dominated by Streptococcus, Veillonella, Haemophilus, Fusobacterium, Trichococcus and Actinomyces . HOMA mice and human microbiota-associated (HMA) mice along with the GF mice were then cohoused. Microbial communities of cohoused mice clustered together and were significantly separated from those of HOMA mice and HMA mice. The Source Tracker analysis and network analysis revealed more significant ecological invasion from oral bacteria in the small intestines, compared to the distal gut, of cohoused mice. In conclusion, a HOMA mouse model was successfully established. By overcoming the physical and microbial barrier, oral bacteria colonised the gut and profiled the gut microbiota, especially in the small intestine.
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