Strain-level characterization of health-associated bacterial consortia that colonize the human gut during infancy.

Background: The human gut microbiome develops rapidly during infancy, a key window of development coinciding with maturation of the adaptive immune system. However, little is known of the microbiome growth dynamics over the first few months of life and whether there are any generalizable patterns across human populations. We performed metagenomic sequencing on stool samples (n=94) from a cohort of infants (n=15) at monthly intervals in the first six months of life, augmenting our dataset with seven published studies for a total of 4,441 metagenomes from 1,162 infants. Results: Strain-level de novo analysis was used to identify 592 of the most abundant organisms in the infant gut microbiome. Previously unrecognized consortia were identified which exhibited highly correlated abundances across samples and were composed of diverse species spanning multiple genera. Analysis of a cohort of infants with cystic fibrosis identified one such novel consortium of diverse Enterobacterales which was positively correlated with weight gain. While all studies showed an increased community stability during the first year of life, microbial dynamics varied widely in the first few months of life, both by study and by individual. Conclusion: By augmenting published metagenomic datasets with data from a newly established cohort we were able to identify novel groups of organisms that are correlated with measures of robust human development. We hypothesize that the presence of these groups may impact human health in aggregate in ways that individual species may not in isolation.

Maternal urinary cadmium concentrations in early pregnancy in relation to prenatal and postpartum size of offspring.

BACKGROUND: The impacts of environmental cadmium (Cd) exposure on birth size parameters including weight, length and head circumference (HC) have been reported in multiple studies. However, little remains known of the impacts of maternal Cd exposure during pregnancy on size during in utero development and during early childhood. The aim of this study was to comprehensively investigate impacts of maternal Cd exposure during pregnancy on the size of offspring in utero (from 24 weeks pregnancy) until six months of age. METHODS: Pregnant mothers were recruited as part of an ongoing prospective birth cohort study based in Guangdong, China. Maternal urine samples were collected in the first and third trimesters of pregnancy, in which Cd concentrations were measured by inductively couple plasma mass spectrometry (ICPMS). In utero size indicators at 24 and 32 week of gestation, including biparietal diameter (BPD), abdominal circumference (AC), femur length (FL) and HC were derived from ultrasound examinations. Anthropometric measures of weight, height and HC at birth and one, three and six months of age were also collected. Associations of size measures at the various time points with maternal urinary Cd concentrations were assessed using linear regression models. RESULTS: The median urinary Cd concentration was 1.00 and 0.98 µg/g creatinine in the first and third trimesters respectively. In univariate analysis, increased maternal Cd levels in the first trimester were associated with decreased HC (-0.17 cm/ug/g urinary Cd) at birth, and the association was particularly pronounced among males (-0.30 cm/ug/g urinary Cd). First trimester Cd exposure was also found to be significantly associated with decreased infant weight at three and six months of age among girls (-101 g/ug/g and -97 g/ug/g urinary Cd, respectively). Associations of similar magnitude were observed after adjustment for various maternal factors. No significant associations were observed with infant size measures or with measures of Cd in the third trimester. CONCLUSIONS: Our detailed study suggests that the first trimester is particularly critical window of susceptibility to sex-specific effects of Cd on size parameters at birth, with some effects persisting to six months of age. These compelling sex-dependent effects on HC and body weight warrant future studies examining longer-term health effects of pregnancy-related Cd exposures.

Early-Onset Preeclampsia Is Associated With Gut Microbial Alterations in Antepartum and Postpartum Women.

Background: Imbalances in gut microbiota composition are linked to hypertension, host metabolic abnormalities, systemic inflammation, and other conditions. In the present study, we examined the changes of gut microbiota in women with early-onset preeclampsia (PE) and in normotensive, uncomplicated pregnant women during late pregnancy and at 1 and 6 weeks postpartum. Methods: Gut microbiota profiles of women with PE and healthy pregnant women in the third trimester and at 1 and 6 weeks postpartum were assessed by 16S rRNA gene amplicon sequencing. Plasma levels of interleukin-6 (IL-6), intestinal fatty acid-binding protein (I-FABP), zonulin, and lipopolysaccharide (LPS) were measured in the third trimesters. Results: At the genus level, 8 bacterial genera were significantly enriched in the antepartum samples of PE patients compared to healthy controls, of which Blautia, Ruminococcus2, Bilophila, and Fusobacterium represented the major variances in PE microbiomes. Conversely, 5 genera, including Faecalibacterium, Gemmiger, Akkermansia, Dialister, and Methanobrevibacter, were significantly depleted in antepartum PE samples. Maternal blood pressure and liver enzyme levels were positively correlated to the PE-enriched genera such as Anaerococcus, Ruminococcus2, Oribacterium, and Bilophila, while the fetal features (e.g., Apgar score and newborn birth weight) were positively correlated with PE-depleted genera and negatively correlated with PE-enriched genera. Moreover, maternal blood IL-6 level was positively associated with gut Bilophila and Oribacterium, whereas LPS level was negatively associated with Akkermansia. In terms of postpartum women, both the gut microbial composition and the PE-associated microbial alterations were highly consistent with those of the antepartum women. Conclusion: PE diagnosed in the third trimester of pregnancy is associated with a disrupted gut microbiota composition compared with uncomplicated pregnant women, which are associated with maternal clinical features (blood pressure level and liver dysfunction) and newborn birth weight. Moreover, these antepartum alterations in gut microbiota persisted 6 weeks postpartum.

Whole-genome sequencing of esophageal adenocarcinoma in Chinese patients reveals distinct mutational signatures and genomic alterations.

While the incidence of esophageal adenocarcinoma (EAC) has risen drastically in Western countries over the last 40 years, a similar trend has not been observed for EAC in China. Here, we analyzed mutational spectrum, copy number alterations, and structural variants from whole-genome sequencing of 10 Chinese EAC tumor samples and their matched normal samples, and compared them to previously reported EAC tumor specimens from Western countries. The mutational burden in Chinese EAC was significantly lower than that found in EAC from Western countries. The hallmark A>C mutational signature observed at high frequency in EAC from Western countries, which has been linked to acid reflux, is completely absent in Chinese samples. Furthermore, none of the Chinese samples showed evidence of chromothripsis and genome doubling that are often found in EAC from Western countries. In summary, Chinese EAC tumor samples had distinct genomic profiles and signatures, suggesting that EAC in Chinese individuals may arise from a different etiological pathway.

Increased H. pylori stool shedding and EPIYA-D cagA alleles are associated with gastric cancer in an East Asian hospital.

BACKGROUND: Helicobacter pylori infection increases risk for gastric cancer. Geographic variation in gastric cancer risk has been attributed to variation in carriage and type of the H. pylori oncogene cagA. Colonization density may also influence disease and cagA has been associated with higher shedding in stool. However, the relationship between H. pylori load in the stool and in the stomach is not clear. METHODS: To investigate possible differences in H. pylori load in the stomach and shedding in stool, H. pylori load and cagA genotype were assessed using droplet digital PCR assays on gastric mucosa and stool samples from 49 urea breath test-positive individuals, including 25 gastric cancer and 24 non-cancer subjects at Henan Cancer Hospital, Henan, China. RESULTS: Quantitation of H. pylori DNA indicated similar gastric loads among cancer and non-cancer cases, but the gastric cancer group had a median H. pylori load in the stool that was six times higher than that of the non-cancer subjects. While the cagA gene was uniformly present among study subjects, only 70% had the East Asian cagA allele, which was significantly associated with gastric cancer (Fisher's Exact Test, p = 0.03). CONCLUSION: H. pylori persists in a subset of gastric cancer cases and thus may contribute to cancer progression. In this East Asian population with a high prevalence of the cagA gene, the East Asian allele could still provide a marker for gastric cancer risk. IMPACT: This study contributes to our understanding of H. pylori dynamics in the context of pathological changes.

Droplet Digital PCR-Based Detection of Clarithromycin Resistance in Helicobacter pylori Isolates Reveals Frequent Heteroresistance.

Chronic infection with Helicobacter pylori causes peptic ulcers and stomach cancer in a subset of infected individuals. While standard eradication therapy includes multiple antibiotics, treatment failure due to resistance is an increasing clinical problem. Accurate assessment of H. pylori antimicrobial resistance has been limited by slow growth and sampling of few isolates per subject. We established a method to simultaneously quantify H. pylori clarithromycin-resistant (mutant) and -susceptible (wild-type) 23S rRNA gene alleles in both stomach and stool samples using droplet digital PCR (ddPCR). In 49 subjects, we assessed the performance of these assays alongside clarithromycin MIC testing of up to 16 H. pylori isolates per subject and included both cancer (25 subjects) and noncancer (24 subjects) cases. Gastric ddPCR and H. pylori culture showed agreement with urea breath test (UBT) detection of infection in 94% and 88% of subjects, respectively, while stool ddPCR showed agreement with UBT in 92% of subjects. Based on MIC testing of 43 culture-positive cases, 20 subjects had only susceptible isolates, 14 had a mix of susceptible and resistant isolates, and 9 had only resistant isolates. ddPCR of gastric samples indicated that 21 subjects had only wild-type alleles, 13 had a mixed genotype, and 9 had only mutant alleles. Stool ddPCR detected mutant alleles in four subjects for which mutant alleles were not detected by stomach ddPCR, and no resistant isolates were cultured. Our results indicate that ddPCR detects H. pylori clarithromycin resistance-associated genotypes, especially in the context of heteroresistance.

Esophageal Adenocarcinoma and Its Rare Association with Barrett's Esophagus in Henan, China.

Incidence of esophageal adenocarcinoma (EAC) has increased sharply in Western Europe and United States over the past three decades. Nearly all cases of EAC in the west are thought to be associated with Barrett's esophagus (BE) at the time of diagnosis. Regions in the Henan province of China have one of world's highest incidences of esophageal cancer, yet recent temporal trends in the relative rates of EAC with respect to esophageal squamous-cell carcinoma (ESCC), as well as its association with Barrett's esophagus (BE), have not been reported. In this report, we present large-scale longitudinal clinical and histological data on 5401 esophageal cancers (EC) patients diagnosed during the recent 10-year period (2002-2011) at Henan Cancer Hospital, China. All 217 esophageal adenocarcinoma (EAC) patients from these 5401 EC patients were examined to better understand the relationship between Barrett's esophagus (BE) and EAC. We found that EAC was relatively rare and accounted for approximately 5% of all esophageal cancers each year during 2002-2011. There is no evidence of significant temporal trends in the rate of EAC relative to ESCC. Only 10 out of 217 (4.6%) EAC cases were detected to have any evidence of Barrett's esophagus. This result raises the possibility of a different etiological basis for EAC in China motivating more detailed epidemiological, clinical and molecular characterization of EAC in China in order to better understand the neoplastic development of EAC.

IL-31 is associated with cutaneous lymphocyte antigen-positive skin homing T cells in patients with atopic dermatitis.

BACKGROUND: IL-31 is a newly discovered T-cell cytokine that, when overexpressed in mice, results in pruritus and skin dermatitis resembling human atopic dermatitis (AD). OBJECTIVE: We sought to investigate the expression of IL-31 and IL-31 receptor A (IL-31RA) in skin biopsy specimens and peripheral blood cells from patients with AD and healthy individuals. METHODS: Expression of IL-31 and IL-31RA was evaluated in skin biopsy specimens from patients with AD and healthy individuals by means of immunohistochemistry and RT-PCR. IL-31 protein production by skin-homing cutaneous lymphocyte antigen (CLA)-positive T cells was also assessed. RESULTS: IL-31RA protein was expressed by keratinocytes and infiltrating macrophages in skin biopsy specimens from patients with AD. Comparisons between skin from patients with AD and healthy skin showed IL-31RA expression at higher levels on epidermal keratinocytes in AD samples. Infiltrating cells, more numerous in skin from patients with AD compared with that of healthy individuals, expressed IL31 mRNA. Histomorphometric analysis of these cells indicated they were of the lymphocytic lineage, with the majority of cells staining positive for CLA and CD3. IL31 mRNA and protein expression is largely restricted to CD45RO(+) (memory) CLA(+) T cells in peripheral blood of patients with AD and healthy volunteers. Moreover, circulating CLA(+) T cells from patients with AD, but not from patients with psoriasis, are capable of producing higher levels of IL-31 compared with CLA(+) T cells from healthy individuals. However, the average levels of IL-31 were not significantly different between patients with AD and healthy individuals. CONCLUSION: We provide evidence that IL-31 expression is associated with CLA(+) T cells and might contribute to the development of AD-induced skin inflammation and pruritus.

A glycoprotein hormone expressed in corticotrophs exhibits unique binding properties on thyroid-stimulating hormone receptor.

Corticotroph-derived glycoprotein hormone (CGH), also referred to as thyrostimulin, is a noncovalent heterodimer of glycoprotein hormone alpha 2 (GPHA2) and glycoprotein hormone beta 5 (GPHB5). Here, we demonstrate that both subunits of CGH are expressed in the corticotroph cells of the human anterior pituitary, as well as in skin, retina, and testis. CGH activates the TSH receptor (TSHR); (125)I-CGH binding to cells expressing TSHR is saturable, specific, and of high affinity. In competition studies, unlabeled CGH is a potent competitor for (125)I-TSH binding, whereas unlabeled TSH does not compete for (125)I-CGH binding. Binding and competition analyses are consistent with the presence of two binding sites on the TSHR transfected baby hamster kidney cells, one that can interact with either TSH or CGH, and another that binds CGH alone. Transgenic overexpression of GPHB5 in mice produces elevations in serum T(4) levels, reductions in body weight, and proptosis. However, neither transgenic overexpression of GPHA2 nor deletion of GPHB5 produces an overt phenotype in mice. In vivo administration of CGH to mice produces a dose-dependent hyperthyroid phenotype including elevation of T(4) and hypertrophy of cells within the inner adrenal cortex. However, the distinctive expression patterns and binding characteristics of CGH suggest that it has endogenous biological roles that are discrete from those of TSH.

Interleukins 19, 20, and 24 signal through two distinct receptor complexes. Differences in receptor-ligand interactions mediate unique biological functions.

Cytokines that signal through Class II receptors form a distinct family that includes the interferons and interleukin 10 (IL-10). Recent identification of several IL-10 homologs has defined a cytokine subfamily that includes AK155, IL-19, IL-20, IL-22, and IL-24. Within this subfamily, IL-19, IL-20, and IL-24 exhibit substantial sharing of receptor complexes; all three are capable of signaling through IL-20RA/IL-20RB, and IL-20 and IL-24 both can also use IL-22R/IL-20RB. However, the biological effects of these three cytokines appear quite distinct: immune activity with IL-19, skin biology with IL-20, and tumor apoptosis with IL-24. To more fully elucidate their interactions with the receptor complexes, we have performed a series of in vitro assays. Reporter, proliferation, and direct STAT activation assays using cell lines expressing transfected receptors revealed differences between the receptor complexes. IL-19 and IL-24 also exhibited growth inhibition on a cell line endogenously expressing all three receptor subunits, an effect that was seen at cytokine levels two orders of magnitude above those required for STAT activation or proliferation. These results demonstrate that, although this subclass exhibits receptor complex redundancy, there are differences in ligand/receptor interactions and in signal transduction that may lead to specificity and a distinct biology for each cytokine.

Hypothermic protection of the ischemic heart via alterations in apoptotic pathways as assessed by gene array analysis.

Hypothermia improves resistance to ischemia in the cardioplegia-arrested heart. This adaptive process produces changes in specific signaling pathways for mitochondrial proteins and heat-shock response. To further test for hypothermic modulation of other signaling pathways such as apoptosis, we used various molecular techniques, including cDNA arrays. Isolated rabbit hearts were perfused and exposed to ischemic cardioplegic arrest for 2 h at 34 degrees C [ischemic group (I); n = 13] or at 30 degrees C before and during ischemia [hypothermic group (H); n = 12]. Developed pressure, the maximum first derivative of left ventricular pressure, oxygen consumption, and pressure-rate product (P < 0.05) recovery were superior in H compared with in I during reperfusion. mRNA expression for the mitochondrial proteins, adenine translocase and the beta-subunit of F1-ATPase, was preserved by hypothermia. cDNA arrays revealed that ischemia altered expression of 13 genes. Hypothermia modified this response to ischemia for eight genes, six related to apoptosis. A marked, near fivefold increase in transformation-related protein 53 in I was virtually abrogated in H. Hypothermia also increased expression for the anti-apoptotic Bcl-2 homologue Bcl-x relative to I but decreased expression for the proapoptotic Bcl-2 homologue bak. These data imply that hypothermia modifies signaling pathways for apoptosis and suggest possible mechanisms for hypothermia-induced myocardial protection.

Expression of IL-17B in neurons and evaluation of its possible role in the chromosome 5q-linked form of Charcot-Marie-Tooth disease.

IL-17B is a recently identified homolog of IL-17. Northern analysis revealed that IL-17B mRNA is expressed at very high levels in spinal cord and at much lower and more variable levels in trachea, prostate, lung, small intestine, testes, adrenal, and pancreas. In developing mouse embryos IL-17B expression was first detected at day 11 and appeared to peak at day 15. In situ analysis of mouse spinal cord, dorsal root ganglia, and brain demonstrated that IL-17B mRNA is primarily expressed by the neurons. Immunohistochemical analysis of human spinal cord, dorsal root ganglia, cerebral cortex, cerebellum, and hippocampus demonstrated that IL-17B protein is primarily localized to the neuronal cell bodies and axons. Radiation hybrid mapping localized the IL-17B gene to a region on human chromosome 5q that is associated with a rare autosomal recessive form of Charcot-Marie-Tooth demyelinating disease. However, no changes were found in the coding regions, splice junctions, intron 1, or the 5' and 3' untranslated regions of IL-17B genes of patients affected with this disease.