Serum exosomal microRNA-144-3p: a promising biomarker for monitoring Crohn's disease

The miRNA Landscape in Crohn's disease: Implications for novel therapeutic approaches and interactions with Existing therapies

MicroRNAs (miRNAs), which are non-coding RNAs consisting of 18-24 nucleotides, play a crucial role in the regulatory pathways of inflammatory diseases. Several recent investigations have examined the potential role of miRNAs in forming Crohn's disease (CD). It has been suggested that miRNAs serve as diagnostics for both fibrosis and inflammation in CD due to their involvement in the mechanisms of CD aggravation and fibrogenesis. More information on CD pathophysiology could be obtained by identifying the miRNAs concerned with CD and their target genes. These findings have prompted several in vitro and in vivo investigations into the putative function of miRNAs in CD treatment. Although there are still many unanswered questions, the growing body of evidence has brought miRNA-based therapy one step closer to clinical practice. This extensive narrative study offers a concise summary of the most current advancements in CD. We go over what is known about the diagnostic and therapeutic benefits of miRNA mimicry and inhibition so far, and we see what additional miRNA family targets could be useful for treating CD-related inflammation and fibrosis.

Plasma exosomes from patients with active thyroid-associated orbitopathy induce inflammation and fibrosis in orbital fibroblasts

BACKGROUND

The pathogenesis of thyroid-associated orbitopathy (TAO) remains incompletely understand. The interaction between immunocytes and orbital fibroblasts (OFs) play a critical role in orbital inflammatory and fibrosis. Accumulating reports indicate that a significant portion of plasma exosomes (Pla-Exos) are derived from immune cells; however, their impact upon OFs function is unclear.

METHODS

OFs were primary cultured from inactive TAO patients. Exosomes isolated from plasma samples of patients with active TAO and healthy controls (HCs) were utilized for functional and RNA cargo analysis. Functional analysis in thymocyte differentiation antigen-1+ (Thy-1+) OFs measured expression of inflammatory and fibrotic markers (mRNAs and proteins) and cell activity in response to Pla-Exos. RNA cargo analysis was performed by RNA sequencing and RT-qPCR. Thy-1+ OFs were transfected with miR-144-3p mimics/inhibitors to evaluate its regulation of inflammation, fibrosis, and proliferation.

RESULTS

Pla-Exos derived from active TAO patients (Pla-ExosTAO-A) induced stronger production of inflammatory cytokines and hyaluronic acid (HA) in Thy-1+ OFs while inhibiting their proliferation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and single sample gene set enrichment analysis (ssGSEA) suggested that the difference in mRNA expression levels between Pla-ExosTAO-A and Pla-ExosHC was closely related to immune cells. Differential expression analysis revealed that 62 upregulated and 45 downregulated miRNAs in Pla-ExosTAO-A, with the elevation of miR-144-3p in both Pla-Exos and PBMCs in active TAO group. KEGG analysis revealed that the target genes of differentially expressed miRNA and miR-144-3p enriched in immune-related signaling pathways. Overexpression of the miR-144-3p mimic significantly upregulated the secretion of inflammatory cytokines and HA in Thy-1+ OFs while inhibiting their proliferation.

CONCLUSION

Pla-Exos derived from patients with active TAO were immune-active, which may be a long-term stimulus casual for inflammatory and fibrotic progression of TAO. Our finding suggests that Pla-Exos could be used as biomarkers or treatment targets in TAO patients.

Bile acid profiles and classification model accuracy for inflammatory bowel disease diagnosis

To investigate the utility of serum bile acid profiling for the diagnosis of inflammatory bowel disease (IBD). We analyzed 15 specific bile acids in the serum of 269 IBD patients, 200 healthy controls (HC), and 174 patients with other intestinal diseases (OID) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum bile acid levels were compared between IBD group, HC group, and OID group. Binary logistic regression-based models were developed to model the bile acids and diagnose IBD. Furthermore, receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic accuracy of each bile acid and the model. Compared to HC group, IBD group exhibited significantly lower levels of chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), glycodeoxycholic acid (GDCA), taurodeoxycholic acid (TDCA), lithocholic acid (LCA), glycolithocholic acid (GLCA), taurolithocholic acid (TLCA), and an elevated primary-to-secondary bile acid ratio. DCA had an area under the curve (AUC) of 0.860 for diagnosing IBD, with a sensitivity of 80.67% and a specificity of 82.50%. A model Y0 combining DCA and CDCA to distinguish between IBD group and HC group further improved accuracy (AUC = 0.866, sensitivity = 76.28%, specificity = 89.37%). Compared to non-IBD group (which combined healthy controls and those with other intestinal diseases), IBD group had significantly lower levels of DCA, GDCA, TDCA, LCA, GLCA, and TLCA, and elevated levels of glycocholic acid (GCA) and glycochenodeoxycholic acid (GCDCA). A model Y1 incorporating GCDCA, DCA and TLCA to distinguish between IBD group and non-IBD group yielded an AUC of 0.792, with a sensitivity of 77.67% and specificity of 71.91%. IBD patients exhibit decreased serum secondary bile acid levels and an elevated primary-to-secondary bile acid ratio. Serum bile acid alterations are associated with the onset of IBD. A model consisting of CDCA and DCA has potential for distinguishing between IBD group and HC group, while a model incorporating GCDCA, DCA and TLCA may be suitable for distinguishing between IBD group and non-IBD group.

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.

Efficacy of extracellular vesicles as a cell-free therapy in colitis: a systematic review and meta-analysis of animal studies

Background: Extracellular vesicles (EVs) mediate inflammation, immune responses, gut barrier integrity, and intestinal homeostasis. Recently, the application of EVs in the treatment of inflammatory bowel disease (IBD) has been under intensive focus. Some studies have been conducted in animal models of colitis, while systematic reviews and meta-analyses are lacking. The current study aimed to conduct a systematic review and meta-analysis of studies investigating the efficacy of EVs on IBD. Methods: A systematic retrieval of all studies in PubMed, EMBASE, MEDLINE, Web of Science, and Cochrane Library reported the effects of EVs in the colitis model up to 22 June 2023. The methodological quality was assessed based on SYRCLE's risk of bias (RoB) tool. Disease activity index (DAI), myeloperoxidase activity (MPO), histopathological score (HS), and inflammatory cytokines (TNF-α, NF-κB, IL-1β, IL-6, and IL-10) were extracted as analysis indicators by Web Plot Digitizer 4.5. A meta-analysis was performed to calculate the standardized mean difference and 95% confidence interval using random-effect models by Review Manager 5.3 and STATA 14.0 software. Results: A total of 21 studies were included in this meta-analysis. Although the heterogeneity between studies and the potential publication bias limits confidence in the extent of the benefit, EV treatment was superior to the control in the colitis evaluation with reduced DAI, HS, MPO activity, and pro-inflammatory cytokines, including TNF-α, NF-κB, IL-1β, and IL-6, while increasing the content of anti-inflammatory cytokine IL-10 (all p < 0.05). Conclusion: Our meta-analysis results supported the protective effect of EVs on colitis rodent models based on their potential role in IBD therapy and propelling the field toward clinical studies.

miRNA effects on gut homeostasis: therapeutic implications for inflammatory bowel disease

Inflammatory bowel disease (IBD) spans a range of chronic conditions affecting the gastrointestinal (GI) tract, which are marked by intermittent flare-ups and remissions. IBD results from microbial dysbiosis or a defective mucosal barrier in the gut that triggers an inappropriate immune response in a genetically susceptible person, altering the immune-microbiome axis. In this review, we discuss the regulatory roles of miRNAs, small noncoding RNAs with gene regulatory functions, in the stability and maintenance of the gut immune-microbiome axis, and detail the challenges and recent advances in the use of miRNAs as putative therapeutic agents for treating IBD.