HDAC6 inhibitor ACY-1215 protects from nonalcoholic fatty liver disease via inhibiting CD14/TLR4/MyD88/MAPK/NFκB signal pathway.

Background & aims: Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by hepatic steatosis, for which there is currently no effective treatment. ACY-1215 is a selective inhibitor of histone deacetylation 6, which has shown therapeutic potential in many tumors, as well as acute liver injury. However, no research about ACY-1215 on NAFLD has been published. Therefore, our study aims to explore the role and mechanism of ACY-1215 in the experimental model of NAFLD, to propose a new treatment strategy for NAFLD. Methods: We established cell and animal models of NAFLD and verified the effect of ACY-1215 on NAFLD. The mechanism of ACY-1215 on NAFLD was preliminarily explored through TMT relative quantitative proteomics, and then we verify the mechanism discovered in the experimental model of NAFLD. Results: ACY-1215 can reduce lipid aggregation, IL-1ß, and TNF α mRNA levels in liver cells in vitro. ACY-1215 can reduce the weight gain and steatosis in the liver of the NAFLD mouse model, alleviate the deterioration of liver function, and reduce IL-1ßs and TNF α mRNA levels in hepatocytes. TMT relative quantitative proteomics found that ACY-1215 decreased the expression of CD14 in hepatocytes. It was found that ACY-1215 can inhibit the activation level of CD14/TLR4/MyD88/MAPK/NFκB pathway in the NAFLD experimental model. Conclusions: ACY-1215 has a protective effect on the cellular model of NAFLD induced by fatty acids and lipopolysaccharide, as well as the C57BL/6J mouse model induced by a high-fat diet. ACY-1215 may play a protective role by inhibiting CD14/TLR4/MyD88/MAPK/NFκB signal pathway.

Associations between sex hormones, receptors, binding proteins and inflammatory bowel disease: a Mendelian randomization study.

Background: Gender differences existed in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Observational studies have revealed associations between sex hormones and IBD, such as estrogen and testosterone. However, the exact relationship between these sex hormones and IBD is unclear. Method: Based on the genome-wide association studies data of eight sex hormones, two sex hormone receptors, sex hormone-binding globulin (SHBG), total IBD and its two subtypes, we performed a two-sample Mendelian randomization (MR) study to analyze their mutual relationship. For estradiol (E2), progesterone (PROG), bioavailable testosterone (BAT), total testosterone (TT) and SHBG, sex-stratified MR analyses were also performed. Inverse variance weighted method, MR-Egger regression and Weighted median method were used for causal analyses. Sensitivity analyses were conducted to test the stability of causal relationships. Besides, a reverse MR analysis was performed to estimate the reverse causation. Results: E2 (P=0.028) and TT (P=0.034) had protective effects on CD. Sex-stratified analyses revealed protective roles of E2 in males on total IBD (P=0.038) and CD (P=0.020). TT in females had protective effects on total IBD (P=0.025) and CD (P=0.029), and BAT in females decreased the risk of developing CD (P=0.047) and UC (P=0.036). Moreover, SHBG in males was also associated with a decreased risk of CD (P=0.021). The reversed MR analysis showed that CD was negatively correlated with estrogen receptor (P=0.046). UC was negatively correlated with PROG in females (P=0.015) and positively correlated with SHBG levels in males (P=0.046). Conclusion: Findings of this study revealed the mutual causal associations between sex hormones and the risk of developing IBD.

Chronic Diarrhea with Villous Blunting of the Small Intestine Under Capsule Endoscopy in Common Variable Immunodeficiency and X-Linked Agammaglobulinemia: A Case Series.

Introduction: Primary immunodeficiencies (PIDs) are a heterogeneous group of disorders, common variable immunodeficiency disorder (CVID) and X-linked agammaglobulinemia (XLA) are PIDs related to B-cell defect, characterized by reduced levels of immunoglobulins and immune dysregulation. Infections are the most common clinical manifestations, while underlying autoimmune and inflammatory conditions are present in some patients with CVID and XLA, leading to clinical misdiagnosis and diagnostic delay. Chronic diarrhea in patients with CVID and XLA, particularly complicated malabsorption and protein-energy malnutrition, is responsible for poor prognostic outcomes. Methods: In this study, we described three PID adult patients (two with CVID and one with XLA) who presented with varying degrees of chronic diarrhea, weight loss, and protein-energy malnutrition. We suggest that villous blunting of the small intestine under capsule endoscopy may be an endoscopic feature of PID-related enteropathy, thus highlighting the application of capsule endoscopy in patients with CVID and XLA presenting with chronic diarrhea. Conclusion: We also summarize regular Ig supplementation is the basic treatment for CVID and XLA patients, proper enteral nutrition and probiotic therapy can be explored to use to alter gut microbiota and modulate intestinal immune response. However, vedolizumab is not helpful to PID-related enteropathy therapy, as it exacerbates the inflammatory response in extra-intestinal organs and ultimately causes poor clinical outcomes.

Systemic immune-inflammation index as a potential biomarker to monitor ulcerative colitis.

OBJECTIVE: The treat-to-target strategy is recommended by Selecting Therapeutic Targets in Inflammatory Bowel Disease II (STRIDE-II) for treating ulcerative colitis (UC), and monitoring remission status is crucial during this management. The systemic immune-inflammation index (SII), defined as platelet * neutrophil/lymphocyte, is a complete blood count-based index reflecting the balance of immune and inflammatory status. This study aims to investigate the feasibility of SII for diagnosing UC and monitoring UC disease activity. METHODS: This study retrospectively analyzed patients with UC and controls. Relationships between SII and Mayo clinical score, Mayo Endoscopic Score (MES), and Nancy Histological Index (NHI) were evaluated. RESULTS: 167 patients with UC and 106 controls were included. SII significantly increased in patients with UC and was closely correlated with the Mayo clinical score, MES, and NHI. SII diagnosed UC with a cut-off value of 619.1 × 109/L (area under the curve = 0.861, p < 0.0001, sensitivity 79.64%, specificity 77.36%), evaluated clinical remission status with a cut-off value of 1068 × 109/L (area under the curve = 0.691, p < 0.05, sensitivity 55.71%, specificity 81.48%), endoscopic improvement with a cut-off value of 981.3 × 109/L (area under the curve = 0.819, p < 0.0001, sensitivity 65.22%, specificity 89.66%), and histological healing with a cut-off value of 689.3 × 109/L (area under the curve = 0.898, p < 0.0001, sensitivity 88.89%, specificity 95.83%). CONCLUSION: SII is a potential biomarker for diagnosing UC and monitoring UC disease severity, especially in evaluating mucosal and histological healing during the long-term management in treat-to-target strategy. However, further research is needed to confirm its usefulness and optimize its clinical application.

Researchers studied an index calculated from a blood test, named the "systemic immune-inflammation index" (SII), to see if it can identify and track the activity of a bowel condition called ulcerative colitis (UC).They reviewed health records of UC patients and compared them to people without this condition. They specifically checked if the SII test's results aligned with other common tests that show the severity of UC.People with UC tended to have higher SII results. The SII test results were consistent with other tests for UC. Specific scores from the SII test, like 619.1 × 10⁹/L, can indicate someone might have UC. What's more, this test can give clues about inflammation in the bowel, saving some from more invasive tests like a colonoscopy or biopsy.The SII test could be a promising way for doctors to diagnose UC and gauge its activity without needing more intrusive tests. However, more studies are required to fully trust this approach.

The role of sphingosine-1-phosphate in the gut mucosal microenvironment and inflammatory bowel diseases.

Sphingosine-1-phosphate (S1P), a type of bioactive sphingolipid, can regulate various cellular functions of distinct cell types in the human body. S1P is generated intracellularly by the catalysis of sphingosine kinase 1/2 (SphK1/2). S1P is transferred to the extracellular environment via the S1P transporter, binds to cellular S1P receptors (S1PRs) and subsequently activates S1P-S1PR downstream signaling. Dysbiosis of the intestinal microbiota, immune dysregulation and damage to epithelial barriers are associated with inflammatory bowel disease (IBD). Generally, S1P mainly exerts a proinflammatory effect by binding to S1PR1 on lymphocytes to facilitate lymphocyte migration to inflamed tissues, and increased S1P was found in the intestinal mucosa of IBD patients. Notably, there is an interaction between the distribution of gut bacteria and SphK-S1P signaling in the intestinal epithelium. S1P-S1PR signaling can also regulate the functions of intestinal epithelial cells (IECs) in mucosa, including cell proliferation and apoptosis. Additionally, increased S1P in immune cells of the lamina propria aggravates the inflammatory response by increasing the production of proinflammatory cytokines. Several novel drugs targeted at S1PRs have recently been used for IBD treatment. This review provides an overview of the S1P-S1PR signaling pathway and, in particular, summarizes the various roles of S1P in the gut mucosal microenvironment to deeply explore the function of S1P-S1PR signaling during intestinal inflammation and, more importantly, to identify potential therapeutic targets for IBD in the SphK-S1P-S1PR axis.

Alterations in the gut microbiota and the efficacy of adjuvant probiotic therapy in liver cirrhosis.

Background: Liver cirrhosis is the end stage of various chronic liver diseases (CLDs). The gut microbiota can impact the liver environment and trigger chronic liver inflammation through the gut-liver axis. Alteration of the gut microbiota has become an effective strategy in the biological treatment of cirrhosis. Methods: Twenty-eight patients with liver cirrhosis and 16 healthy individuals were included, and fresh stool samples were collected. We analyzed changes in the gut microbiota between groups by 16S rRNA sequencing and evaluated the association between microbiota alterations and hepatic function. Additionally, 102 cirrhotic patients were retrospectively enrolled and divided into a probiotic group (n=44) and a nonprobiotic group (n=58) in addition to standard treatment for cirrhosis. Patients were monitored for hematological parameters and hepatic function during the six-month follow-up. Results: The gut microbiota profile of patients with cirrhosis was greatly different from that of healthy individuals, presenting with significantly reduced α diversity and decreased abundance of representative SCFA-producing bacteria including Firmicutes, Coprococcus and Clostridium IV. The pathogenic bacteria Gammaproteobacteria, Veillonella, and Bacilli were greatly enriched in cirrhotic patients. Additionally, patients with decompensated cirrhosis (DCPC) had a significantly reduced abundance of Oscillibacter compared to compensated cirrhosis (CPC), which is also a SCFA-producing bacteria, and the lower Firmicutes to Bacteroidetes ratio and enhanced MDR values were also shown in DCPC patients compared to CPC patients. In addition, the abundance of Firmicutes was negatively related to hepatic function in cirrhotic patients, including the levels of ALT, AST, and DBIL. From the retrospective study, we found that biochemical improvements in alanine transaminase (ALT) and total bilirubin (TBIL) were obtained in DCPC patients who received oral probiotic therapy compared with the nonprobiotic group. Conclusion: Severe microbial dysbiosis existed in patients with liver cirrhosis, especially patients who reached the decompensatory stage. SCFA-producing bacteria were significantly reduced in cirrhosis. Altered gut microbiota cause changes in functional modules, which may contribute to cirrhosis progression and are associated with clinical prognosis. Adjuvant probiotic supplementation to enhance SCFA-producing bacteria can be a prospective therapy for patients with cirrhosis.

Regulators, functions, and mechanotransduction pathways of matrix stiffness in hepatic disease.

The extracellular matrix (ECM) provides physical support and imparts significant biochemical and mechanical cues to cells. Matrix stiffening is a hallmark of liver fibrosis and is associated with many hepatic diseases, especially liver cirrhosis and carcinoma. Increased matrix stiffness is not only a consequence of liver fibrosis but is also recognized as an active driver in the progression of fibrotic hepatic disease. In this article, we provide a comprehensive view of the role of matrix stiffness in the pathological progression of hepatic disease. The regulators that modulate matrix stiffness including ECM components, MMPs, and crosslinking modifications are discussed. The latest advances of the research on the matrix mechanics in regulating intercellular signaling and cell phenotype are classified, especially for hepatic stellate cells, hepatocytes, and immunocytes. The molecular mechanism that sensing and transducing mechanical signaling is highlighted. The current progress of ECM stiffness's role in hepatic cirrhosis and liver cancer is introduced and summarized. Finally, the recent trials targeting ECM stiffness for the treatment of liver disease are detailed.

KCNJ14 knockdown significantly inhibited the proliferation and migration of colorectal cells.

BACKGROUND: This study attempted to verify the potential of KCNJ14 as a biomarker in colorectal cancer (CRC). METHODS: Data on transcriptomics and DNA methylation and the clinical information of CRC patients were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus databases. Biological information analysis methods were conducted to determine the role of KCNJ14 in the prognosis, diagnosis, immune cell infiltration, and regulation mechanism of CRC patients. The effect of KCNJ14 on the proliferation and migration of HCT116 and SW480 CRC cell lines was verified by in vitro experiments (MTT, colony-forming, wound healing, and transwell assays). Western blotting was performed to detect the effect of KCNJ14 on the levels of mTOR signalling pathway-related proteins. RESULTS: KCNJ14 expression was remarkably increased in CRC tissues and cell lines, which reduced the overall survival time of patients. KCNJ14 mRNA was negatively regulated by its methylation site cg17660703, which can also endanger the prognosis of patients with CRC. Functional enrichment analysis suggested that KCNJ14 is involved in the mTOR, NOD-like receptor, and VEGF signalling pathways. KCNJ14 expression was positively correlated with the number of CD4 + T cells and negatively correlated with that of CD8 + T cells in the immune microenvironment. KCNJ14 knockdown significantly reduced not only the proliferation and migration of CRC cell lines but also the levels of mTOR signalling pathway-related proteins. CONCLUSIONS: This study not only increases the molecular understanding of KCNJ14 but also provides a potentially valuable biological target for the treatment of colorectal cancer.

YAP Activates STAT3 Signalling to Promote Colonic Epithelial Cell Proliferation in DSS-Induced Colitis and Colitis Associated Cancer.

Background and Aims: Yes-associated protein (YAP) is a key transcriptional coactivator of cell proliferation and differentiation. In this study, we sought to identify the roles of YAP in colonic epithelial regeneration and tumourigenesis. Methods: Murine DSS-induced colitis and YAP overexpression models were constructed via lentiviral intraperitoneal injection. Stable YAP-overexpressing cells, protein immunoprecipitation, and ChIP were used to deeply explore the molecular mechanism. Results: We found that the expression of YAP was dramatically diminished in the colonic crypts during the acute colitis phase, while YAP was strikingly enhanced to initiate tissue repair after DSS withdrawal. Overexpressing YAP in mice drastically accelerated epithelial regeneration, presenting with more intact structural integrity and reduced inflammatory cell infiltration in the mucosa. Further mechanistic studies showed that the expression of YAP in the nucleus was significantly increased by 2 h post-DSS removal, accompanied by upregulated protein levels of activated STAT3. Overexpression of YAP (YAPWT) elevated the expression of activated STAT3 and its transcriptional targets and strengthened the proliferation and "wound healing" ability of colonic cells. However, these effects were reversed when STAT3 was silenced in YAPWT cells. Moreover, YAP could directly interact with STAT3 in the nucleus, and c-Myc and CyclinD1 were the transcriptional targets. Finally, during colitis-associated cancer (CAC), YAPWT promoted the progression of CAC, while the phosphomimetic YAP downregulated the expression of STAT3 and inhibited the development and progression of CAC. Conclusion: YAP activates STAT3 signalling to facilitate mucosal regeneration after DSS-induced colitis. However, excessive YAP activation in the colonic epithelium promotes CAC development.

The Hippo-YAP/TAZ Signaling Pathway in Intestinal Self-Renewal and Regeneration After Injury.

The Hippo pathway and its downstream effectors, the transcriptional coactivators Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), control stem cell fate and cell proliferation and differentiation and are essential for tissue self-renewal and regeneration. YAP/TAZ are the core components of the Hippo pathway and they coregulate transcription when localized in the nucleus. The intestinal epithelium undergoes well-regulated self-renewal and regeneration programs to maintain the structural and functional integrity of the epithelial barrier. This prevents luminal pathogen attack, and facilitates daily nutrient absorption and immune balance. Inflammatory bowel disease (IBD) is characterized by chronic relapsing inflammation of the entire digestive tract. Impaired mucosal healing is a prominent biological feature of IBD. Intestinal self-renewal is primarily dependent on functional intestinal stem cells (ISCs), especially Lgr5+ crypt base columnar (CBC) cells and transient-amplifying (TA) cells in the crypt base. However, intestinal wound healing is a complicated process that is often associated with epithelial cells, and mesenchymal and immune cells in the mucosal microenvironment. Upon intestinal injury, nonproliferative cells rapidly migrate towards the wound bed to reseal the damaged epithelium, which is followed by cell proliferation and differentiation. YAP is generally localized in the nucleus of Lgr5+ CBC cells, where it transcriptionally regulates the expression of the ISC marker Lgr5 and plays an important role in intestinal self-renewal. YAP/TAZ are the primary mechanical sensors of the cellular microenvironment. Their functions include expanding progenitor and stem cell populations, reprogramming differentiated cells into a primitive state, and mediating the regenerative function of reserve stem cells. Thus, YAP/TAZ play extremely crucial roles in epithelial repair after damage. This review provides an overview of the Hippo-YAP/TAZ signaling pathway and the processes of intestinal self-renewal and regeneration. In particular, we summarize the roles of YAP/TAZ in the phases of intestinal self-renewal and regeneration to suggest a potential strategy for IBD treatment.

The Role of Vitamin D in Immune System and Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a nonspecific inflammatory disease that includes ulcerative colitis (UC) and Crohn's disease (CD). The pathogenesis of IBD is not fully understood but is most reported associated with immune dysregulation, dysbacteriosis, genetic susceptibility, and environmental risk factors. Vitamin D is an essential nutrient for the human body, and it not only regulates bone metabolism but also the immune system, the intestinal microbiota and barrier. Vitamin D insufficiency is common in IBD patients, and the abnormal low levels of vitamin D are highly correlated with disease activity, treatment response, and risk of relapse of IBD. Accumulating evidence supports the protective role of vitamin D in IBD through regulating the adaptive and innate immunity, maintaining the intestinal barrier and balancing the gut microbiota. This report aims to provide a broad overview of the role vitamin D in the immune system, especially in the pathogenesis and treatment of IBD, and its possible role in predicting relapse.

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OBJECTIVES: Ulcerative colitis (UC) is a chronic, relapsing inflammation of the colon. Impaired epithelial repair is an important biological features of UC. Accelerating intestinal epithelial repair to achieve endoscopic mucosal healing has become a key goal in UC. Yes-associated protein (YAP) is a key transcriptional coactivator that regulates organ size, tissue growth and tumorigenesis. Growing studies have focused on the role of YAP in intestinal epithelial regeneration. This study explore the molecular mechanism for the role YAP in modulating colonic epithelial proliferation, repair, and the development of colitis associated cancer. METHODS: We constructed the acute colitis mouse model through successive 5 days of 3% dextran sulfate sodium salt (DSS) induction. Then YAP-overexpressed mouse model was constructed by intraperitoneal injection the YAP overexpressed and negative control lentivirus into DSS mice. On the 5th day of DSS induction and the 5th day of normal drinking water after removing DSS (5+5 d), the mice were killed by spinal dislocation. The colon was taken to measure the length, and the bowel 1-2 cm near the anal canal was selected for immunohistochemical and Western blotting. We used YAP over-expressed colonic epithelial cells and small interfering signal transducer and activator of transcription 3 (STAT3) RNA to probe the regulation of YAP on STAT3, using cell counting kit-8 and scratch assays to explore the role of YAP on colonic epithelial cell proliferation. Finally, we conducted co-immunoprecipitation to test the relationship between YAP and STAT3. RESULTS: After DSS treatment, the expression of YAP was dramatically diminished in crypts. Compared with the empty control mice, overexpression of YAP drastically accelerated epithelial regeneration after DSS induced colitis, presenting with more intact of structural integrity in intestinal epithelium and a reduction in the number of inflammatory cells in the mucosa. Further Western blotting, functional experiment and co-immunoprecipitation analyses showed that the expression of YAP in nucleus was significantly increased by 2 h post DSS cessation, accompanied with up-regulated total protein levels of STAT3 and phosphorylated-STAT3 (p-STAT3). Overexpression of YAP enhanced the expression of STAT3, p-STAT3, and their transcriptional targets including c-Myc and Cyclin D1. In addition, it promoted the proliferation and the "wound healing" of colonic cells. However, these effects were reversed when silencing STAT3 on YAP-overexpressed FHC cells. Moreover, protein immunoprecipitation indicated that YAP could directly interact with STAT3 in the nucleus, up-regulatvng the expressvon of STAT3. Finally, during the process of CAC, overexpression of YAP mutant caused the down-regulated expression of STAT3 and inhibited the development and progress of CAC. CONCLUSIONS: YAP activates STAT3 signaling in regulation of epithelial cell proliferation and promotes mucosal regeneration after DSS induced colitis, which may serve as a potential therapeutic target in UC. However, persistent and excessive YAP activation may promote CAC development.

Perianal and Luminal Relapse Following Perianal Surgical Intervention in Crohn's Disease.

BACKGROUND AND AIMS: Fistula relapse occurs in 20-30% of patients with perianal Crohn's disease (PCD) despite optimal medico-surgical management. We aimed in this study to assess the rate of perianal and luminal relapse after surgically induced remission and to determine factors associated with fistula relapse. METHODS: Consecutive perianal CD patients who achieved clinical remission after surgery for fistulising PCD from January 2013 to January 2019 were included. The cumulative probabilities of relapse-free survival were estimated using the Kaplan-Meier method. RESULTS: A total of 130 patients were included. Sixty-six of 130 patients received infliximab (IFX) therapy after perianal surgery. After a median follow-up of 62 months (interquartile range [IQR]: 28-117 months), perianal relapse occurred in 30 of 64 (46.9%) nonbiological medication-treated cases and in 14 of 66 (21.1%) cases in the IFX therapy group. The cumulative probabilities of perianal relapse-free survival in patients with nonbiological treatment were 77.1% at 1 year, 54.6% at 3 years, and 30% at 5 years. The rates of survival without perianal fistula relapse in the IFX-treated group were 91.6%, 69.2%, and 59.3% at 1, 3 and 5 years, respectively. In patients treated with IFX after perianal surgery, discontinuation of IFX therapy (odds ratio [OR]=2.43, p=0.036), a penetrating CD phenotype (OR=4.324, p=0.019), and a complex perianal fistula (OR=3.392, p=0.026) were independently associated with perianal relapse in multivariate analysis. CONCLUSION: Infliximab therapy reduced the risk of perianal relapse after surgical remission in PCD patients compared with nonbiological treatment. However, approximately 40% of patients using infliximab experienced perianal relapse at 5 years, and patients who discontinued use of IFX or experienced a penetrating phenotype or a complex perianal fistula were associated with increased relapse rate.

Thalidomide Attenuates Colitis and Is Associated with the Suppression of M1 Macrophage Polarization by Targeting the Transcription Factor IRF5.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The TNF-α inhibitor thalidomide is reported to be effective for inducing remission in pediatric Crohn's disease (CD) and adults with refractory CD. The mechanisms underlying the immunomodulatory and anti-inflammatory properties of thalidomide are unclear. METHODS: Histological assessments were firstly performed in thalidomide treated UC patients. Then the effect of thalidomide in vivo was detected in DSS-induced murine colitis. The mechanism involving IRF5, and M1 macrophage polarization was investigated by using plasmid transfection, western blotting, and real-time PCR. Finally, AOM/DSS model was used to detect the role of thalidomide in colitis associated cancer. RESULTS: We first found that treatment with thalidomide could ameliorate colon inflammation for 8 weeks and promote mucosal healing in human UC. Moreover, treatment with thalidomide protected mice from dextran sodium sulfate (DSS)-induced acute colitis, with treated mice presenting with a higher body weight, lower histological score, and lower DAI. Concomitantly, in comparison with control mice, mice treated with thalidomide showed accelerated recovery following colitis after 10 days of thalidomide treatment. Mechanistically, we observed that thalidomide could increase epithelial cell self-renewal capacity and modulate M1/M2 polarization by decreasing M1 markers CD86 and CCR7 and increasing M2 protein signatures CD206 and Arg-1. Thalidomide controls M1 macrophage polarization by targeting the transcription factor IRF5. Finally, by using the classical AOM/DSS model, we found that thalidomide-treated mice presented with a lower incidence and growth of colitis-associated carcinoma (CAC) than negative control mice. CONCLUSIONS: In summary, thalidomide suppresses M1 polarization in the inflammatory microenvironment, which not only attenuates colonic inflammation to facilitate mucosal healing after DSS-induced injury but also represses the progression of CAC.

M1 Macrophage exosomes MiR-21a-5p aggravates inflammatory bowel disease through decreasing E-cadherin and subsequent ILC2 activation.

Abnormal immune regulation is a key feature of the complex pathogenic mechanism of ulcerative colitis (UC). In particular, macrophages and group 2 innate lymphoid cells (ILC2s) are important components of natural immunity that have been shown to play important roles in the pathogenesis of UC, as well as decreased E-cadherin expression on the colonic mucosa. However, it remains unclear how these components interact with each other. In this study, we investigated the molecular mechanisms of UC mediated by macrophage-derived exosomes. We showed for the first time that miR-21a-5p expression is increased in the peritoneal exosomes of mice with dextran sulphate sodium induced enteritis and that miR-21a-5p expression correlates negatively with E-cadherin expression in enterocytes. Moreover, we confirmed that miR-21a-5p was mainly derived from M1 macrophages and demonstrated that KLRG1, a surface inhibitory receptor on ILC2s, participated in excessive ILC2 activation in UC by promoting GATA-3. In conclusion, our results suggest molecular targets and provide a theoretical basis for elucidating the pathogenesis of UC and improving its treatment.

M2 Macrophage-Derived Exosomal miR-590-3p Attenuates DSS-Induced Mucosal Damage and Promotes Epithelial Repair via the LATS1/YAP/ ß-Catenin Signalling Axis.

BACKGROUND AND AIMS: M2 phenotype macrophages are involved in the resolution of inflammation and intestinal repair. Exosomes are emerging as important mediators of intercellular communication in the mucosal microenvironment. METHODS: M2 macrophages were transfected with or without miR-590-3p. Exosomes derived from M2 macrophages were isolated and identified. Proliferation and wound healing were tested in vitro and compared between groups. The mechanism involving LATS1, and activation of YAP and ß-catenin signalling was investigated by using plasmid transfection, western blotting, immunofluorescence and luciferase reporter assays. The effect of exosomes in vivo was detected in dextran saline sulphate [DSS]-induced murine colitis. RESULTS: First, we demonstrated that M2 macrophages promoted colonic epithelial cell proliferation in an exosome-dependent manner. Epithelial YAP mediated the effect of M2 macrophage-derived exosomes [M2-exos] in epithelial proliferation. Moreover, miR-590-3p, which was significantly enriched in M2-exos, could be transferred from macrophages into epithelial cells, resulting in the enhanced proliferation and wound healing of epithelial cells. Mechanistically, miR-590-3p suppressed the expression of LATS1 by binding to its coding sequence and subsequently activated the YAP/ß-catenin-modulated transcription process to improve epithelial cell wound-healing ability. miR-590-3p also inhibited the induction of pro-inflammatory cytokines, including tumour necrosis factor-α, interleukin-1ß [IL-1ß] and IL-6. More importantly, repression of miR-590-3p in M2-exos resulted in more severe mucosal damage and impaired colon repair of mice compared with those in M2-exo-treated mice after DSS-induced colitis. CONCLUSION: M2 macrophage-derived exosomal miR-590-3p reduces inflammatory signals and promotes epithelial regeneration by targeting LATS1 and subsequently activating YAP/ß-catenin-regulated transcription, which could offer a new opportunity for clinical therapy for ulcerative colitis.

SET7 interacts with HDAC6 and suppresses the development of colon cancer through inactivation of HDAC6.

SET7 is the first lysine methyltransferase and plays vital roles in tumorigenesis. This study aims to seek clinical value of SET7 in colorectal cancer (CRC) patients, along with its biological impact on cell proliferation and migration. In patients with CRC, the expression of SET7 in cancer tissue was significantly lower than that in adjacent tissue, and down-regulated SET7 was closely correlated with poor prognosis. Loss-of-function and gain-of-function studies indicated that SET7 inhibited cell proliferation and migration by acting on HDAC6 substrate in colon cancer cells. Besides, the co-immunoprecipitation assay showed that SET7 and HDAC6 can interact reciprocally. The interaction effect between SET7 and HDAC6 could significantly reduce cell viability, scratch healing rate, and migrated cells in colon cancer cells. Instead of acting on each endogenous expression, the results demonstrated that the level of acetylated α-tubulin was greatly decreased in HDAC6 overexpression group, while significantly increased in SET7 overexpressed group. However, changes were partly restored in both SET7 and HDAC6-transfected group. On the contrary, the expression of acetylated α-tubulin protein was significantly increased in HDAC6 knockdown group, but higher in both HDAC6 and SET7 silencing group. These results indicated that SET7 played a role in tumor suppression via increasing levels of acetylated-α-tubulin mediated by HDAC6. In addition, the interaction effect significantly decreased the ratios of p-ERK/ERK, which indicated that it may partly suppress ERK signaling pathway. In conclusion, SET7 is a promising therapeutic target for preventing metastasis and improving prognosis in colon cancer.

Genetic Variations at rs3129891 and rs77005575 are Associated With Reduced Expression of Enteric α-defensins in IBD Patients.

BACKGROUND AND AIMS: Human enteric antimicrobial peptides composed predominantly of human enteric α-defensins (HD5 and HD6) are important in the mucosal antimicrobial barrier. Previous studies have identified that genetic variations at rs2066844, rs2066845, rs2066847 are associated with diminished enteric α-defensins in ileal Crohn's disease (CD). However, genetic variations associated with enteric antimicrobial peptides in colonic inflammatory bowel disease (IBD) remain unclear. To investigate it, we compared the colonic expression of antimicrobial peptides with respect to genotypes at 22 IBD-associated single-nucleotide polymorphisms (SNPs). MATERIALS AND METHODS: In total, 16 controls and 102 colonic IBD patients including 42 ulcerative colitis (UC) and 60 CD were studies. Mutation assay was performed to determine their genotypes at 22 IBD-associated SNPs. Real-time PCR was performed to determine the colonic mRNA expression of HD5, HD6, lysozyme, and secretory phospholipase A2. RESULTS: Mutant genotypes at rs2066844, rs2066845, rs2066847 were not found, and only SNPs rs3129891 and rs77005575 were associated with enteric α-defensin expression in colonic IBD. In both inflamed and noninflamed tissues, colonic expression of HD5 and HD6 was significantly decreased in UC and CD patients carrying rs3129891 homozygous mutant genotype. And their colonic expression was significantly decreased in inflamed but not noninflamed tissues from UC patients carrying rs77005575 homozygous mutant genotype. However, both lysozyme and secretory phospholipase A2 in UC and CD were unaffected by rs3129891 and rs77005575 genotypes. CONCLUSIONS: As enteric α-defensins play critical roles in the mucosal antimicrobial barrier, their reduced expression may partly explain the microbial-induced mucosal inflammation in colonic IBD patients, especially in patients carrying rs3129891 and rs77005575 mutant genotypes.

Submucosal Tunneling Endoscopic Resection for Gastric Submucosal Tumors: a Comparison Between Cardia and Non-cardia Location.

BACKGROUND AND PURPOSE: Submucosal tunneling endoscopic resection (STER) was initially used to remove submucosal tumors (SMTs) located at the esophagus and cardia; only few researchers have reported the feasibility of STER for gastric SMTs beyond cardia due to the technical difficulty, and little is known about the comparison of STER for cardia and non-cardia gastric SMTs. The purpose was to compare the feasibility and efficacy of STER for cardia and non-cardia gastric SMTs, as well as to explore the risk factors for failure of en bloc resection. METHODS: We retrospectively collected the clinical data about patients with gastric SMTs who received STER at our hospital from June 2012 to June 2018. Demographics, tumor size, procedure-related parameters, complications, hospital stay, and follow-up data were compared between cardia and non-cardia SMTs. And multivariate analyses were conducted to look for the risk factors for failure of en bloc resection. RESULTS: A total of 46 SMTs were removed, and 25 of them were located at cardia, while the other 21 at non-cardia position. There was no significant difference between the two groups in terms of gender, age, tumor size, en bloc resection rate, operation time, complications, and hospital stay (p > 0.05). No recurrence was noticed in all the cases. Multivariate analyses revealed that irregular shape was an independent risk factor for failure of en bloc resection. CONCLUSION: STER is feasible for both cardia and non-cardia gastric SMTs, and the efficacy between cardia and non-cardia location is comparable. Irregular shape was an independent risk factor for failure of en bloc resection.

A Molecular Targeted Immunotherapeutic Strategy for Ulcerative Colitis via Dual-targeting Nanoparticles Delivering miR-146b to Intestinal Macrophages.

BACKGROUND AND AIMS: Macrophages are a promising therapeutic target for intestinal mucosal repair. MiR-146b appears to control macrophage activation and cell proliferation. METHODS: By loading miR-146b mimic on mannose-modified trimethyl chitosan [MTC]-conjugated nanoparticles [NPs] [MTC-miR146b], a molecular targeted immunotherapeutic approach was developed to selectively target intestinal macrophages for mucosal regeneration and tumourigenesis in mouse models. RESULTS: We first confirmed that miR-146b expression was significantly enhanced during mucosal regeneration in a murine colitis model. Moreover， after mucosal damage, MTC-miR146b mimic-treated wild-type mice had dramatically restored body weight and mucosal barrier function compared with MTC-NC treated mice. Strikingly, MTC-miR146b mimic oral administration protected miR-146b-deficient mice from dextran sodium sulphate [DSS] injury and the colitis-associated cancer process. Mechanistically, miR-146b strongly inhibited M1 macrophage activation by suppressing the Toll-like receptor 4 [TLR4] signalling pathway, resulting in the repression of the induction of pro-inflammatory cytokines including TNF-α, IL-6, and IL-1ß. More importantly, miR-146b overexpression in bone marrow-derived macrophages [BMDMs] in M1 differentiation conditions induced a phenotype similar to M2 macrophages and improved the proliferation of co-cultured colonic epithelial cells via STAT3-dependent IL-10 production. CONCLUSIONS: MTC-miR146b should be regarded as an effective candidate for oral delivery and could improve the efficacy of immunotherapies for ulcerative colitis and colitis-associated cancer.