Host Genetic and Gut Microbial Signatures in Familial Inflammatory Bowel Disease

Placental Histopathological Lesions and Adverse Neonatal Outcomes in Patients with Inflammatory Bowel Diseases- A retrospective Cohort Study

Inflammatory bowel diseases (IBD) are significantly associated with adverse pregnancy and neonatal outcomes, though the pathomechanism is yet unknown. To investigate the relationship between IBD and adverse pregnancy outcomes by comparing neonatal outcomes and placental histopathology in two matched groups of patients with and without IBD. In this retrospective study, data of all patients who gave birth between 2008-2021 and were diagnosed with IBD were reviewed and compared to a control group matching two control cases for every IBD case. Neonatal outcomes and placental pathology were compared between the groups. Compared to the control group (n=76), the placentas of patients with IBD (n=36) were characterized by significantly lower placental weight (p < 0.001), and higher rates of maternal vascular malperfusion lesions (MVM, p < 0.001) and maternal and fetal inflammatory response lesions (p < 0.001). Neonates of patients with IBD were more frequently small for gestational age (SGA) (p=0.01), with increased rates of need for phototherapy (p = 0.03), respiratory morbidity and NICU admission (p < 0.001 for both outcomes). Multivariate logistic regression analyses adjusting for possible confounders (including maternal age, gestational age, chronic hypertension, smoking, and thrombophilia) confirmed the independent association between IBD and composite MVM lesions (aOR 4.31, p < 0.001), maternal inflammatory responses (aOR 40.22, p < 0.001) and SGA infants (aOR 4.31, p = 0.013). IBD is associated with increased rates of placental histopathological lesions and adverse pregnancy outcomes, including SGA infants. These novel findings imply the role of placental malperfusion and inflammatory processes in pregnancy complications of IBD patients, which should be followed accordingly. Approval of local ethics committee # WOMC-0219-20.

miR-92b ameliorates lipoteichoic acid induced endometritis by suppressing Wnt/β-catenin pathway activation

Endometritis is one of the important reasons for the low fecundity of dairy cows, which has brought huge economic losses to the dairy industry. Emerging evidence suggests that miR-92b is a novel therapeutic molecule that plays a crucial role in many inflammatory diseases. However, its mechanism in lipoteichoic acid (LTA) induced endometritis remains unclear. In the present study, we explored the mechanism of miR-92b on LTA-induced endometritis in vivo and in vitro. The result displayed that the expression of miR-92b was reduced in LTA induced mouse endometritis and bovine endometrial epithelial cell lines (BEND). Overexpression miR-92b significantly alleviated mouse uterine injury and reduced the protein levels of TNF-α, IL-1β and the MPO activity. The reporter assay of luciferase showed that miR-92b directly targeted the transmembrane receptor Frizzled-10 (FZD10), a transmembrane-type Wnt receptor. Molecular experiments were further performed to explore the mechanism of miR-92b in protecting LTA induced endometritis. The results of in vitro suggested that miR-92b mimic decreased the protein levels of Wnt3a and β-catenin in LTA stimulated BEND, which were abolished by overexpression of FZD10. As expected, miR-92b mimic decreased the expression levels of TNF-α and IL-1β, while overexpression of FZD10 promoted the production of these pro-inflammatory cytokines. Collectively, the above findings indicated that miR-92b might be an effective strategy for treatment of LTA induced endometritis.

Why U matters: detection and functions of pseudouridine modifications in mRNAs

The uridine modifications pseudouridine (Ψ), dihydrouridine, and 5-methyluridine are present in eukaryotic mRNAs. Many uridine-modifying enzymes are associated with human disease, underscoring the importance of uncovering the functions of uridine modifications in mRNAs. These modified uridines have chemical properties distinct from those of canonical uridines, which impact RNA structure and RNA-protein interactions. Ψ, the most abundant of these uridine modifications, is present across (pre-)mRNAs. Recent work has shown that many Ψs are present at intermediate to high stoichiometries that are likely conducive to function and at locations that are poised to influence pre-/mRNA processing. Technological innovations and mechanistic investigations are unveiling the functions of uridine modifications in pre-mRNA splicing, translation, and mRNA stability, which are discussed in this review.

Analysis of genetic variability in Turner syndrome linked to long-term clinical features

Background

Women with Turner syndrome (TS) (45,X and related karyotypes) have an increased prevalence of conditions such as diabetes mellitus, obesity, hypothyroidism, autoimmunity, hypertension, and congenital cardiovascular anomalies (CCA). Whilst the risk of developing these co-morbidities may be partly related to haploinsufficiency of key genes on the X chromosome, other mechanisms may be involved. Improving our understanding of underlying processes is important to develop personalized approaches to management.

Objective

We investigated whether: 1) global genetic variability differs in women with TS, which might contribute to co-morbidities; 2) common variants in X genes - on the background of haploinsufficiency - are associated with phenotype (a "two-hit" hypothesis); 3) the previously reported association of autosomal TIMP3 variants with CCA can be replicated.

Methods

Whole exome sequencing was undertaken in leukocyte DNA from 134 adult women with TS and compared to 46,XX controls (n=23), 46,XX women with primary ovarian insufficiency (n=101), and 46,XY controls (n=11). 1) Variability in autosomal and X chromosome genes was analyzed for all individuals; 2) the relation between common X chromosome variants and the long-term phenotypes listed above was investigated in a subgroup of women with monosomy X; 3) TIMP3 variance was investigated in relation to CCA.

Results

Standard filtering identified 6,457,085 autosomal variants and 126,335 X chromosome variants for the entire cohort, whereas a somatic variant pipeline identified 16,223 autosomal and 477 X chromosome changes. 1) Overall exome variability of autosomal genes was similar in women with TS and control/comparison groups, whereas X chromosome variants were proportionate to the complement of X chromosome material; 2) when adjusted for multiple comparisons, no X chromosome gene/variants were strongly enriched in monosomy X women with key phenotypes compared to monosomy X women without these conditions, although several variants of interest emerged; 3) an association between TIMP3 22:32857305:C-T and CCA was found (CCA 13.6%; non-CCA 3.4%, p<0.02).

Conclusions

Women with TS do not have an excess of genetic variability in exome analysis. No obvious X-chromosome variants driving phenotype were found, but several possible genes/variants of interest emerged. A reported association between autosomal TIMP3 variance and congenital cardiac anomalies was replicated.

The Role of IL-23 in the Pathogenesis and Therapy of Inflammatory Bowel Disease

Interleukin-23 (IL-23) is a proinflammatory cytokine produced mainly by macrophages and antigen-presenting cells (APCs) after antigenic stimulation. IL-23 plays a significant role as a mediator of tissue damage. Indeed, the irregularities in IL-23 and its receptor signaling have been implicated in inflammatory bowel disease. IL-23 interacts with both the innate and adaptive immune systems, and IL-23/Th17 appears to be involved in the development of chronic intestinal inflammation. The IL-23/Th17 axis may be a critical driver of this chronic inflammation. This review summarizes the main aspects of IL-23's biological function, cytokines that control cytokine production, effectors of the IL-23 response, and the molecular mechanisms associated with IBD pathogenesis. Although IL-23 modulates and impacts the development, course, and recurrence of the inflammatory response, the etiology and pathophysiology of IBD are not completely understood, but mechanism research shows huge potential for clinical applications as therapeutic targets in IBD treatment.

The genetics of non-monogenic IBD

Inflammatory bowel disease (IBD), with Crohn's disease and ulcerative colitis as main subtypes, is a prototypical multifactorial disease with both genetic and environmental factors involved. Genetically, IBD covers a wide spectrum from monogenic to polygenic forms. In polygenic disease, many genetic variants each contribute a small amount to disease risk. With the advent of genome-wide association studies (GWAS), it became possible to find these variants and corresponding genes, leading so far to the discovery of ca 240 loci associated with IBD. Together, these however explain only 20-25% of the heritability of IBD, leaving a large portion unaccounted for. This missing heritability might be hidden in common variants with even lower effect than the ones currently found through GWAS, but also in rare variants which can be found through large-scale sequencing studies or potentially in multiplex families. In this review, we will give an overview of the current knowledge about the genetics of non-monogenic IBD and how it differs from the monogenic form(s), and future perspectives. The history of IBD genetic studies from twin studies over linkage studies to GWAS, and finally large-scale sequencing studies and the revisiting of multiplex families will be discussed.

Clinical Phenotype and Disease Course of Inflammatory Bowel Disease: A Comparison Between Sporadic and Familial Cases

BACKGROUND

The role of genetic and environmental factors in inflammatory bowel disease's (IBD) clinical course is not fully clear. We aimed to assess the clinical phenotype, disease course, and prognosis of familial IBD in comparison with sporadic cases.

METHODS

We conducted a prospective national matched case-control study of registered IBD patients in the Iranian Registry of Crohn's and Colitis (IRCC) recruited from 2017 until 2020. Sporadic and familial IBD patients were matched based on age, sex, and disease duration. Data on demographics, past medical disease, family history of IBD, disease type, clinical phenotype, extraintestinal manifestations, IBD medications, IBD activity using the IBD-control-8 questionnaire and the Manitoba IBD index, emergency visits in the past 12 months, admissions in the past 3 months, history of colon cancer, IBD-related surgeries, and aggressive phenotype were gathered. Variable distributions were compared between sporadic and familial cases.

RESULTS

Overall, 5231 patients with ulcerative colitis (UC, 18.3% familial) and 1438 patients with Crohn's disease (CD, 16.7% familial) were registered in the IRCC. Age at diagnosis was similar between familial and sporadic cases. After matching, 3523 UC patients and 908 CD patients were enrolled in the study. Extraintestinal manifestations, UC extent, CD location and behavior, anti-TNF use, disease activity, colon cancer, IBD-related surgeries and the aggressive phenotype were similar between these sporadic and familial cases.

CONCLUSIONS

The prevalence of familial UC and CD cases in Iran was more similar to western countries, and family history did not show a predictive value for disease phenotype, course, and outcomes in our study.

Prebiotic effects of goji berry in protection against inflammatory bowel disease

The prevalence of inflammatory bowel disease (IBD) is increasing, which is concerning because IBD is a known risk factor for the development of colorectal cancer. Emerging evidence highlights environmental factors, particularly dietary factors and gut microbiota dysbiosis, as pivotal inducers of IBD onset. Goji berry, an ancient tonic food and a nutraceutical supplement, contains a range of phytochemicals such as polysaccharides, carotenoids, and polyphenols. Among these phytochemicals, L. barbarum polysaccharides (LBPs) are the most important functional constituents, which have protective effects against oxidative stress, inflammation, and neurodegeneration. Recently, the beneficial effects of goji berry and associated LBPs consumption were linked to prebiotic effects, which can prevent dysbiosis associated with IBD. This review assessed pertinent literature on the protective effects of goji berry against IBD focusing on the gut microbiota and their metabolites in mediating the observed beneficial effects.

Systematic Review: The Gut Microbiome and Its Potential Clinical Application in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting systemic disease of the gastrointestinal tract. It is well established that the gut microbiome has a profound impact on IBD pathogenesis. Our aim was to systematically review the literature on the IBD gut microbiome and its usefulness to provide microbiome-based biomarkers. A systematic search of the online bibliographic database PubMed from inception to August 2020 with screening in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. One-hundred and forty-four papers were eligible for inclusion. There was a wide heterogeneity in microbiome analysis methods or experimental design. The IBD intestinal microbiome was generally characterized by reduced species richness and diversity, and lower temporal stability, while changes in the gut microbiome seemed to play a pivotal role in determining the onset of IBD. Multiple studies have identified certain microbial taxa that are enriched or depleted in IBD, including bacteria, fungi, viruses, and archaea. The two main features in this sense are the decrease in beneficial bacteria and the increase in pathogenic bacteria. Significant differences were also present between remission and relapse IBD status. Shifts in gut microbial community composition and abundance have proven to be valuable as diagnostic biomarkers. The gut microbiome plays a major role in IBD, yet studies need to go from casualty to causality. Longitudinal designs including newly diagnosed treatment-naïve patients are needed to provide insights into the role of microbes in the onset of intestinal inflammation. A better understanding of the human gut microbiome could provide innovative targets for diagnosis, prognosis, treatment and even cure of this relevant disease.