Inhibiting microRNA-7 Expression Exhibited a Protective Effect on Intestinal Mucosal Injury in TNBS-Induced Inflammatory Bowel Disease Animal Model

The miR-7/EGFR axis controls the epithelial cell immunomodulation and regeneration and orchestrates the pathology in inflammatory bowel disease

INTRODUCTION

The epithelial immunomodulation and regeneration are intrinsic critical events against inflammatory bowel disease (IBD). MiR-7 is well documented as a promising regulator in the development of various diseases including inflammatory diseases.

OBJECTIVES

This study aimed to assess the effect of miR-7 in intestinal epithelial cells (IECs) in IBD.

METHODS

MiR-7def mice were given dextran sulfate sodium (DSS) to induce enteritis model. The infiltration of inflammatory cells was measured by FCM and immunofluorescence assay. 5'deletion assay and EMSA assays were performed to study the regulatory mechanism of miR-7 expression in IECs. The inflammatory signals and the targets of miR-7 were analyzed by RNA-seq and FISH assay. IECs were isolated from miR-7def, miR-7oe and WT mice to identify the immunomodulation and regeneration capacity. IEC-specific miR-7 silencing expression vector was designed and administered by the tail vein into murine DSS-induced enteritis model to evaluate the pathological lesions of IBD.

RESULTS

We found miR-7 deficiency improved the pathological lesions of DSS-induced murine enteritis model, accompanied by elevated proliferation and enhanced transduction of NF-κB/AKT/ERK signals in colonic IECs, as well as decreased local infiltration of inflammatory cells. MiR-7 was dominantly upregulated in colonic IECs in colitis. Moreover, the transcription of pre-miR-7a-1, orchestrated by transcription factor C/EBPα, was a main resource of mature miR-7 in IECs. As for the mechanism, EGFR, a miR-7 target gene, was downregulated in colonic IECs in colitis model and Crohn's disease patients. Furthermore, miR-7 also controlled the proliferation and inflammatory-cytokine secretion of IECs in response to inflammatory-signals through EGFR/NF-κB/AKT/ERK pathway. Finally, IEC-specific miR-7 silencing promoted the proliferation and transduction of NF-κB pathway in IECs and alleviated the pathological damage of colitis.

CONCLUSION

Our results present the unknown role of miR-7/EGFR axis in IEC immunomodulation and regeneration in IBD and might provide clues for the application of miRNA-based therapeutic strategies in colonic diseases.

MicroRNA sequencing analysis reveals injury-induced immune responses of Scylla paramamosain against cheliped autotomy

During pond culture or intensive culture system of crabs (mainly Eriocheir sinensis, Portunus trituberculatus and Scylla paramamosain), high-density farming has typically contributed to a higher limb autotomy level in juvenile animals, especially in S. paramamosain which has a high level of cannibalism. Due to the high limb autotomy level, the survival and growth rates in S. paramamosain farming are restricted, which limit the growth of the mud crab farming industry. MicroRNAs (miRNAs) are small noncoding RNAs that regulate a series of biological processes including innate immune responses by post-transcriptional suppression of their target genes. MiRNAs are believed to be crucial for innate immune process of host wound healing. Many miRNAs have been verified to be required in host immune responses to repair wound and to defense pathogen after tissue damage. However, to our best knowledge, the miRNAs functions of crustacean innate immune reactions against injury induced by limb autotomy have not been studied yet. Here in this study, for the first time, miRNAs involved in the S. paramamosain immune reactions against injury induced by cheliped autotomy were obtained by high-throughput sequencing. A total of 575 miRNAs (518 known miRNAs and 57 novel predicted miRNAs) were obtained, of which 141 differentially expressed microRNAs (93 up-regulated microRNAs and 48 down-regulated microRNAs) were revealed to be modified against cheliped autotomy, and the qPCR results of randomly selected miRNAs confirmed the expression patterns in the miRNAs sequencing data. Numerous immune-related target genes associated with innate immune system were mediated by miRNAs to induce host humoral immune and cellular immune defense to minimize acute physical damage. Furthermore, the genes expression in hemolymph coagulation and melanization pathways, as well as Toll and Imd signaling pathways were mediated by miRNAs to activate host immune responses including melanization and antimicrobial peptides for rapid wound healing and killing invaded pathogens. These results will help to understand injury-induced immune responses in crabs and to develop an effective control strategy of autotomy rate in crabs farming.

MiRNA-Based Therapies for the Treatment of Inflammatory Bowel Disease: What Are We Still Missing?

Micro-RNAs (miRNAs) are noncoding RNAs usually 24-30 nucleotides long that play a central role in epigenetic mechanisms of inflammatory diseases and cancers. Recently, several studies have assessed the involvement of miRNAs in the pathogenesis of inflammatory bowel disease (IBD) and colitis-associated neoplasia. Particularly, it has been shown that many members of miRNAs family are involved in the pathways of inflammation and fibrogenesis of IBD; therefore, their use as inflammatory and fibrosis biomarkers has been postulated. In light of these results, the role of miRNAs in IBD therapy has been proposed and is currently under investigation with many in vitro and in vivo studies, murine models, and a phase 2a trial. The accumulating data have pushed miRNA-based therapy closer to clinical practice, although many open questions remain. With this systematic review, we discuss the current knowledge about the therapeutic effects of miRNAs mimicking and inhibition, and we explore the new potential targets of miRNA family for the treatment of inflammation and fibrosis in IBD.

Aryl hydrocarbon receptor activation ameliorates experimental colitis by modulating the tolerogenic dendritic and regulatory T cell formation

Background

Intestinal immune dysfunction is involved in the onset of Crohn’s disease (CD). Dendritic cells (DCs), antigen-presenting cells, play a key role in the maintenance of intestinal immune homeostasis. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor widely expressed in various immune cells, including DCs. Although AhR plays an important role in immune tolerance, its role in the DCs is unclear. The purpose of this study was to investigate whether the activation of AhR can induce tolerogenic DCs (tolDCs) and the differentiation of regulatory T (Treg) cells, as well as ameliorate experimental colitis.

Results

AhR activation in the DCs resulted in a lower expression of surface markers such as CD80, CD83, CD86, and pro-inflammatory cytokine production, and higher anti-inflammatory production (IL-1β, IL-23, and IL-12) compared to the control DCs. The surface dendrites in DCs were significantly reduced following AhR activation by 6-formylindolo [3,2-b]carbazole (FICZ). Such DCs with FICZ-mediated activation of AhR, namely tolDCs, promoted Treg cell differentiation. Adoptive transfer of tolDCs to a TNBS-induced colitis mouse model significantly alleviated the severity of inflammation by improving the colon length and decreasing the disease activity index (DAI) and histopathological score. Moreover, the transferred tolDCs decreased the frequency of Th17 cells and increased the frequency of Treg cells in the spleen and mesenteric lymph nodes (MLNs) in murine colitis models.

Conclusions

Activation of AhR in the DCs could induce tolDCs, and the transplantation of tolDCs may help in relieving intestinal inflammation and maintaining the Th17/Treg differentiation balance. Thus, our data suggest that AhR may be a potential therapeutic target for CD.

Immune-related biomarkers shared by inflammatory bowel disease and liver cancer

It has been indicated that there is an association between inflammatory bowel disease (IBD) and hepatocellular carcinoma (HCC). However, the molecular mechanism underlying the risk of developing HCC among patients with IBD is not well understood. The current study aimed to identify shared genes and potential pathways and regulators between IBD and HCC using a system biology approach. By performing the different gene expression analyses, we identified 871 common differentially expressed genes (DEGs) between IBD and HCC. Of these, 112 genes overlapped with immune genes were subjected to subsequent bioinformatics analyses. The results revealed four hub genes (CXCL2, MMP9, SPP1 and SRC) and several other key regulators including six transcription factors (FOXC1, FOXL1, GATA2, YY1, ZNF354C and TP53) and five microRNAs (miR-124-3p, miR-34a-5p, miR-1-3p, miR-7-5p and miR-99b-5p) for these disease networks. Protein-drug interaction analysis discovered the interaction of the hub genes with 46 SRC-related and 11 MMP9- related drugs that may have a therapeutic effect on IBD and HCC. In conclusion, this study sheds light on the potential connecting mechanisms of HCC and IBD.

The role and mechanisms of miRNA in neonatal necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC), the most significant causes of neonatal mortality, is a disease of acute intestinal inflammation. At present, it is not clear exactly how the disease is caused, but it has been suggested that this disorder is a result of a complex interaction among prematurity, enteral feeding and inappropriate pro-inflammation response and bacterial infection of the intestine. A microRNA (miRNA) is a class of endogenous non-coding single-stranded RNA that is about 23 nucleotides long engaging in the regulation of the gene expression. Recently, numerous studies have determined that abnormal miRNA expression plays important roles in various diseases, including NEC. Here, we summarized the role of miRNAs in NEC. We introduce the biosynthetic and function of miRNAs and then describe the possible mechanisms of miRNAs in the initiation and development of NEC, including their influence on the intestinal epithelial barrier's function and regulation of the inflammatory process. Finally, this review aids in a comprehensive understanding of the current miRNA to accurately predict the diagnosis of NEC and provide ideas to find potential therapeutic targets of miRNA for NEC. In conclusion, our aims are to highlight the close relationship between miRNAs and NEC and to summarize the practical value of developing diagnostic biomarkers and potential therapeutic targets of NEC.

Moxibustion Inhibits the Expression of Colonic NLRP3 through miR7/RNF183/NF-κB Signaling Pathway in UC Rats

Background

Moxibustion has been recognized as an effective approach for ulcerative colitis, yet its mechanism is not clear. The research aimed to investigate the influence of moxibustion on the activation of NLRP3 inflammasome and its mechanism in treating ulcerative colitis by observing miR7/RNF183 inducing IκB α ubiquitination to regulate NF-κB signaling pathway in an ulcerative colitis rat model.

Methods

An ulcerative colitis rat model was established by unlimited access to self-administration of 3.5% (w/v) dextran sulfate sodium solution. Mild moxibustion was applied to bilateral Tianshu points (ST25) in the moxa-stick moxibustion group; rats in the control group were intervened by intraperitoneal injection of ubiquitination inhibitor, MG132. The disease activity index was determined at the end of the intervention; colon injury was observed and scored after hematoxylin-eosin staining; the immunohistochemical method was adopted to detect the expressions of colonic IL-1β and NLRP3 proteins; Western blot determined the expressions of RNF183, IκB α, and NF-κB p65 proteins in the colon; the immunofluorescence test was used to observe the coexpression of IκB α/ubiquitin and IκB α/RNF183 proteins in the colon; immunoprecipitation assay was adopted to observe the interaction between IκB α and RNF183 proteins; and quantitative real-time polymerase chain reaction determined the expression of colonic miR7.

Results

Moxibustion lowered the disease activity index, manifesting as restored colonic tissue and reduced inflammatory reaction, and decreased expression levels of NLRP3 and IL-1β proteins, compared with the model group. It also reduced colonic expression of NF-κB p65 protein, together with the increased level of IκB α protein and weaker expression levels of ubiquitin and RNF183 proteins and mRNAs and stronger expression of miR7. There were no significant differences between the moxa-stick moxibustion group and the control group except the expressions of RNF183 protein and mRNA and miR7.

Conclusion

Moxibustion encourages the recovery of colon injury probably by regulating the expression of NLRP3 protein in ulcerative colitis rats through miR7/RNF183/NF-κB signaling pathway.

Role of MicroRNA in Inflammatory Bowel Disease: Clinical Evidence and the Development of Preclinical Animal Models

The dysregulation of microRNA (miRNA) is implicated in cancer, inflammation, cardiovascular disorders, drug resistance, and aging. While most researchers study miRNA's role as a biomarker, for example, to distinguish between various sub-forms or stages of a given disease of interest, research is also ongoing to utilize these small nucleic acids as therapeutics. An example of a common pleiotropic disease that could benefit from miRNA-based therapeutics is inflammatory bowel disease (IBD), which is characterized by chronic inflammation of the small and large intestines. Due to complex interactions between multiple factors in the etiology of IBD, development of therapies that effectively maintain remission for this disease is a significant challenge. In this review, we discuss the role of dysregulated miRNA expression in the context of clinical ulcerative colitis (UC) and Crohn's disease (CD)-the two main forms of IBD-and the various preclinical mouse models of IBD utilized to validate the therapeutic potential of targeting these miRNA. Additionally, we highlight advances in the development of genetically engineered animal models that recapitulate clinical miRNA expression and provide powerful preclinical models to assess the diagnostic and therapeutic promise of miRNA in IBD.

microRNA in inflammatory bowel disease at a glance

Inflammatory bowel disease (IBD) as a chronic inflammation in colon and small intestine has two subtypes: ulcerative colitis (UC) and Crohn's disease (CD). Genome studies have shown that UC and CD are related to microRNAs (miRNAs) expression in addition to environmental factors. This article reviews important researches that have recently been done on miRNAs roles in CD and UC disease. First, miRNA is introduced and its biogenesis and function are discussed. Afterward, roles of miRNAs in inflammatory processes involved in IBD are showed. Finally, this review proposes some circulating and tissue-specific miRNAs, which are useful for CD and UC fast diagnosis and grade prediction. As a conclusion, miRNAs are efficient diagnostic molecules especially in IBD subtypes discrimination and can be used by microarray and real time PCR methods for disease detection and classification.

The Anti-Inflammatory Immune Response in Early Trichinella spiralis Intestinal Infection Depends on Serine Protease Inhibitor-Mediated Alternative Activation of Macrophages

Trichinella spiralis is recognized for its ability to regulate host immune responses via excretory/secretory (ES) products. Serine protease inhibitors (serpins) play an important role in ES product-mediated immunoregulatory effects during T. spiralis infection. In this study, the immunoregulatory properties of a serpin derived from T. spiralis (Ts-serpin) were explored in BALB/c mice. The results showed that naturally occurring Ts-serpin was detected in the stichosomes of muscle larvae and adult worms. Moreover, enhancing (by injection of a soluble-expressed recombinant Ts-serpin [rTs-serpin]) or blocking (by passive immunization with anti-rTs-serpin serum) the effects of Ts-serpin changed the levels of cytokines related to inflammation induced by T. spiralis infection in the serum, mesenteric lymph nodes, and peritoneal cavity, which then led to a change in the adult worm burden in early T. spiralis infection. Moreover, the phenotypic changes in peritoneal macrophages were found to be related to Ts-serpin-mediated immunoregulation. Furthermore, a STAT6 activation mechanism independent of IL-4Rα has been found to regulate protein-mediated alternative activation of bone marrow-derived macrophages and mimic the immunoregulatory role of Ts-serpin in T. spiralis infection. Finally, the anti-inflammatory properties of rTs-serpin and bone marrow-derived macrophage alternative activation by rTs-serpin were demonstrated using a trinitrobenzene sulfonic acid-induced inflammatory bowel disease model. In summary, a protein-triggered anti-inflammatory mechanism was found to favor the survival of T. spiralis in the early stage of infection and help to elucidate the immunoregulatory effects of T. spiralis on the host immune response.

Exploring the wound healing, anti-inflammatory, anti-pathogenic and proteomic effects of lactic acid bacteria on keratinocytes

The topical application of lactic acid bacteria (LAB) is recognized as a useful approach to improve skin health. This work aims to characterize by a multidisciplinary approach, the wound healing, anti-inflammatory, anti-pathogens and proteomic effects of six LAB lysates, belonging to the genus Lactobacillus. Our results demonstrated that the lysates of tested LAB stimulated the proliferation of keratinocytes, and that L. plantarum SGL 07 and L. salivarius SGL 19 accelerated the re-epithelization by inducing keratinocyte migration. The bacterial lysates also reduced the secretion of specific pro-inflammatory mediators from keratinocytes. Furthermore, viable L. salivarius SGL 19 and L. fermentum SGL 10 had anti-pathogenic effects against S. aureus and S. pyogenes, while L. brevis SGL 12 and L. paracasei SGL 04 inhibited S. aureus and S. pyogenes, respectively. The tested lactobacilli lysates also induced specific proteome modulation of the exposed keratinocytes, involving dysregulation of proteins (such as interleukin enhancer-binding factor 2 and ATP-dependent RNA helicase) and pathways (such as cytokine, NF-kB, Hedgehog, and RUNX signaling) associated with their specific wound healing and anti-inflammatory effects. This study indicates the different potential of selected lactobacilli, suggesting that they may be successfully used in the future together with conventional therapies to bring relief from skin disorders.