Transcriptome-wide association studies associated with Crohn's disease: challenges and perspectives.

Crohn's disease (CD) is regarded as a lifelong progressive disease affecting all segments of the intestinal tract and multiple organs. Based on genome-wide association studies (GWAS) and gene expression data, transcriptome-wide association studies (TWAS) can help identify susceptibility genes associated with pathogenesis and disease behavior. In this review, we overview seven reported TWASs of CD, summarize their study designs, and discuss the key methods and steps used in TWAS, which affect the prioritization of susceptibility genes. This article summarized the screening of tissue-specific susceptibility genes for CD, and discussed the reported potential pathological mechanisms of overlapping susceptibility genes related to CD in a certain tissue type. We observed that ileal lipid-related metabolism and colonic extracellular vesicles may be involved in the pathogenesis of CD by performing GO pathway enrichment analysis for susceptibility genes. We further pointed the low reproducibility of TWAS associated with CD and discussed the reasons for these issues, strategies for solving them. In the future, more TWAS are needed to be designed into large-scale, unified cohorts, unified analysis pipelines, and fully classified databases of expression trait loci.

Association of Neutrophil Extracellular Traps with Fistula Healing in Patients with Complex Perianal Fistulizing Crohn's Disease.

BACKGROUND AND AIMS: Perianal fistulizing Crohn's disease [pfCD] is a disabling phenotype of Crohn's disease [CD] with suboptimal outcomes. We assessed neutrophil extracellular traps [NETs] in perianal fistulas and implicated their roles in pfCD healing. METHODS: Patients with complex pfCD who developed preplaced seton drainage were recruited during the verified maintenance of remission in CD. Fistula tracts were sampled during definitive surgery plus seton removal. Patient demographics, CD classification, medication strategy and healing of pfCD were recorded. RNA sequencing was applied for transcriptomic profile analysis. NET components, including myeloperoxidase [MPO], neutrophil elastase [NE] and citrullinated histone H3 [CitH3], were identified using immunofluorescence. Serum infliximab [IFX], anti-IFX antibodies, and tissue levels of IFX, adalimumab [ADA], MPO and CitH3 were determined using enzyme-linked immunosorbent assays. Peptidyl arginine deiminase IV [PAD4], tumour necrosis factor [TNF]-α, and NE were detected using immunohistochemistry. Gene expression levels of PAD family members were assessed with quantitative PCR. RESULTS: Twenty-one patients were included, 15 of whom adopted IFX as maintenance treatment. RNA-sequencing revealed differences in neutrophil associated pathways between unhealed and healed fistulas. NET components [MPO/NE/CitH3] were detectable in the fistulas and were parallel with the levels of PAD4. Eleven of 21 [52%] patients experienced complete healing of the pfCD 108 weeks post-operatively. Fistula NETs were significantly increased in patients with unhealed pfCD. Increased NETs were associated with abundant TNF-α production and the absence of IFX in fistulas. CONCLUSIONS: NETs exist in pfCD fistulas, which are associated with unhealed post-operative fistulas in pfCD, suggesting their prognostic roles in pfCD.

Breast-Milk Rubidium and Other Trace Elements are Associated with Neurocognitive Development in Infants at Age of 8 Months.

BACKGROUND: Trace elements may affect neurodevelopment. There is a lack of data on breast-milk rubidium (Rb) in relation to neurodevelopment in infants. The associations of copper (Cu), zinc (Zn) and strontium (Sr) with neurodevelopment in infants remain uncertain. OBJECTIVES: We sought to evaluate the associations of breast-milk Rb (primary exposure), Cu, Zn, and Sr with neurodevelopment in infants at age 8 months. METHODS: The study cohort included 117 breastfed infants. Breast-milk samples were collected at 42 days and 8 months postpartum. Breast-milk Rb, Zn, Cu, and Sr were measured by inductively coupled plasma mass spectrometer. Neurodevelopment was assessed at age 8 months. The primary outcomes were attention and working memory scores, as evaluated by the A-not-B task. Other outcomes included the Mental Development Index (MDI) and Psychomotor Development Index (PDI) as evaluated by the Bayley Scale of Infant Development III. Generalized linear models and restricted cubic spline regression were used to assess the associations between trace elements and neurodevelopment indices. Bonferroni correction was conducted on all data presented. RESULTS: A nonlinear association was observed between breast-milk Rb at 42 days and infant's attention at age 8 months (nonlinearity P = 0.037). Positive associations were observed with infant MDI scores and breast-milk Rb at 42 days (ß = 4.46; P = 0.06) and 8 months (ß = 3.79; P = 0.009) postpartum. Breast-milk Zn at 42 days was positively associated with infant's attention (ß = 0.31; P = 0.039). Sr at 42 days was positively correlated with attention (ß = 0.18; P = 0.043) and MDI scores (ß = 2.18; P = 0.015) at 8 months. Inverted U-shape associations were observed for breast-milk Cu at 42 days with infant attention and PDI scores. All associations were not significant after correction for multiple tests. CONCLUSIONS: Our data suggest that Rb, Zn, Cu, and Sr in breast milk at certain concentrations are associated with neurodevelopment in breastfed infants. Further studies are warranted to validate the findings.

Breast milk EPA associated with infant distractibility when EPA level is low.

OBJECTIVES: Dietary ω-3 polyunsaturated fatty acids (ω-3 PUFAs) may affect infants' executive function (EF), although it remains unclear whether this may be the effect of total ω-3 PUFAs or any specific ω-3 PUFA. We assessed the associations between ω-3 PUFAs in breast milk and EF in infants at 8 mo of age. METHODS: Milk samples from the mothers of 120 breast-fed infants were collected at 42 d and 8 mo postpartum in Beijing, China. Infant's EF was evaluated by planning tasks and A-not-B tasks, including working memory, distractibility, and inhibition of prepotent response at age 8 mo. RESULTS: Eicosapentaenoic acid (EPA) concentrations in breast milk were significantly higher at 42 d than 8 mo postpartum. Breast milk EPA levels at both 42 d (P = 0.037) and 8 mo (P = 0.005) postpartum were negatively associated with infant distractibility when EPA levels were low (< 0.05%). No significant association was observed for other ω-3 PUFAs with infant EF scores. CONCLUSIONS: Our results suggest a beneficial effect of higher EPA in breast milk (improving infant's attention) when its levels are below a certain threshold.

Plasma omega-3 polyunsaturated fatty acids and recurrence of endometrial cancer.

BACKGROUND: Omega-3 polyunsaturated fatty acids (PUFAs) were proposed to have potential effects against inflammation and cancer. However, results from epidemiology studies remain inconsistent. We aimed to explore the associations of plasma PUFAs with EC recurrence and all-cause mortality. METHOD: Women diagnosed with endometrial cancer (EC) between 2008 and 2013 and underwent surgery at Fudan University Shanghai Cancer Center of China were recruited. Survival status was followed up through September 2017. EC recurrence and total cause deaths were identified through medical record and telephone interview. In total, 202 patients with enough plasma samples at time of surgery were included. There were 195 patients who provided baseline plasma and survival information included in the current study. Plasma omega-3 PUFAs were measured by GC-FID. Cox Proportional Hazard model adjusted for potential cofounders was used to estimate HRs and 95% CIs. RESULTS: Median follow-up time for patients was 58 months after surgery. A total of 13 recurrences and 11 all-cause deaths, of which, 2 deaths from EC, were identified. Level of plasma EPA was higher in recurrent patients than total patients (0.78% vs 0.51%, P = 0.015). Higher plasma eicosapentaenoic acid (EPA) level trended to have positive association with EC recurrence (P-trend = 0.04), although comparing to the lowest tertile, the highest tertile of EPA level was not significantly associated with increased risk of EC recurrence (HRT3vsT1 = 6.02; 95%CI = 0.7-52.06). The association between total omega-3 PUFA and EC recurrence tended to be stronger among patients with deeper myometrial invasion (OR = 3.41; 95%CI = 1.06-10.95; P-interaction = 0.04). CONCLUSIONS: Higher plasma EPA level was significantly associated with EC recurrence. Further studies are warranted to confirm these findings. TRIAL REGISTRATION: ChiCTR1900025418; Retrospectively registered (26 August 2019); Chinses Clinical Trial Registry.

The associations between plasma phytoestrogens concentration and metabolic syndrome risks in Chinese population.

Metabolic syndrome (MetS) has become an important issue in the healthcare systems of both developed and developing countries. Phytoestrogens have shown estrogenic effects, which may involve in the etiology of MetS. The current study consisted of 293 MetS cases and 264 healthy controls. The concentrations of seven plasma phytoestrogens (daidzein, genistein, glycitein, equol, enterolactone, enterodiol and coumestrol) were detected by UPLC-MS/MS. Adjusted unconditional logistic regression was used to assess the associations between plasma phytoestrogens concentration and risks of MetS, as well as the associations between plasma phytoestrogens concentration and MetS components. Linear regression was used to evaluate the associations between equol concentration in equol-producers and MetS components. Higher concentrations of total isoflavone and equol were associated with decreased risk of MetS. The equol concentration was negatively associated with waist circumference and positively associated with HDL-C level. Increased daidzein was associated with both lower waist circumference and lower fasting blood glucose levels. Our results suggested that higher plasma total isoflavone, equol and daidzein might decrease MetS risk.