Th17 Cell-Derived Amphiregulin Promotes Colitis-Associated Intestinal Fibrosis Through Activation of mTOR and MEK in Intestinal Myofibroblasts.

BACKGROUND & AIMS: Intestinal fibrosis is a significant complication of Crohn's disease (CD). Gut microbiota reactive Th17 cells are crucial in the pathogenesis of CD; however, how Th17 cells induce intestinal fibrosis is still not completely understood. METHODS: In this study, T-cell transfer model with wild-type (WT) and Areg-/- Th17 cells and dextran sulfate sodium (DSS)-induced chronic colitis model in WT and Areg-/- mice were used. CD4+ T-cell expression of AREG was determined by quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of AREG on proliferation/migration/collagen expression in human intestinal myofibroblasts was determined. AREG expression was assessed in healthy controls and patients with CD with or without intestinal fibrosis. RESULTS: Although Th1 and Th17 cells induced intestinal inflammation at similar levels when transferred into Tcrßxδ-/- mice, Th17 cells induced more severe intestinal fibrosis. Th17 cells expressed higher levels of AREG than Th1 cells. Areg-/- mice developed less severe intestinal fibrosis compared with WT mice on DSS insults. Transfer of Areg-/- Th17 cells induced less severe fibrosis in Tcrßxδ-/- mice compared with WT Th17 cells. Interleukin (IL)6 and IL21 promoted AREG expression in Th17 cells by activating Stat3. Stat3 inhibitor suppressed Th17-induced intestinal fibrosis. AREG promoted human intestinal myofibroblast proliferation, motility, and collagen I expression, which was mediated by activating mammalian target of rapamycin and MEK. AREG expression was increased in intestinal CD4+ T cells in fibrotic sites compared with nonfibrotic sites from patients with CD. CONCLUSIONS: These findings reveal that Th17-derived AREG promotes intestinal fibrotic responses in experimental colitis and human patients with CD. Thereby, AREG might serve as a potential therapeutic target for fibrosis in CD.

Downregulation of Setdb2 promotes alternative activation of macrophages via the PI3K/Akt pathway to attenuate NAFLD after sleeve gastrectomy.

Non-alcoholic fatty liver disease (NAFLD) stands as the most prevalent hepatic disorder, with bariatric surgery emerging as the most effective intervention for NAFLD remission. Sleeve gastrectomy (SG) has notably ascended as the predominant procedure due to its comparative simplicity and consistent surgical outcomes. Nonetheless, the underlying mechanisms remain unclear. In this study, we probed the therapeutic potential of SG for NAFLD induced by a high-fat diet (HFD) in mice, with a focus on its impact on liver lipid accumulation, macrophage polarization, and the role of the histone methyltransferase Setdb2. SG prompted significant weight loss, diminished liver size and liver-to-body weight ratio, and enhanced liver function, evidenced by reduced serum levels of triglycerides (TG), total cholesterol (T-CHO), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Histological examination confirmed a reduction in liver lipid accumulation. Additionally, flow cytometry unveiled an increased proportion of M2 macrophages and a decrease in Setdb2 expression was shown in the SG group, suggesting an association between Setdb2 levels and postsurgical macrophage polarization. Furthermore, the conditional knockout of Setdb2 in mice further mitigated HFD-induced steatosis and promoted the M2 macrophage phenotype. Mechanistically, Setdb2 knockout in bone marrow-derived macrophages (BMDMs) favored M2 polarization, with RNA sequencing and western blotting analyses corroborating the upregulation of the PI3K/Akt signaling pathway. The effects of Setdb2 on macrophage activation were nullified by the PI3K inhibitor LY294002, suggesting that Setdb2 facilitates alternative macrophage activation through the PI3K/Akt signaling pathway. These comprehensive findings underscore the potential of SG as a therapeutic intervention for NAFLD by regulating the critical function of Setdb2 in macrophage polarization and activation, thereby offering novel insights into NAFLD pathogenesis and therapeutic targets.

Harnessing ResNet50 and SENet for enhanced ankle fracture identification.

BACKGROUND: Ankle fractures are prevalent injuries that necessitate precise diagnostic tools. Traditional diagnostic methods have limitations that can be addressed using machine learning techniques, with the potential to improve accuracy and expedite diagnoses. METHODS: We trained various deep learning architectures, notably the Adapted ResNet50 with SENet capabilities, to identify ankle fractures using a curated dataset of radiographic images. Model performance was evaluated using common metrics like accuracy, precision, and recall. Additionally, Grad-CAM visualizations were employed to interpret model decisions. RESULTS: The Adapted ResNet50 with SENet capabilities consistently outperformed other models, achieving an accuracy of 93%, AUC of 95%, and recall of 92%. Grad-CAM visualizations provided insights into areas of the radiographs that the model deemed significant in its decisions. CONCLUSIONS: The Adapted ResNet50 model enhanced with SENet capabilities demonstrated superior performance in detecting ankle fractures, offering a promising tool to complement traditional diagnostic methods. However, continuous refinement and expert validation are essential to ensure optimal application in clinical settings.

GPR120 Inhibits Colitis Through Regulation of CD4+ T Cell Interleukin 10 Production.

BACKGROUND & AIMS: G protein-coupled receptor (GPR) 120 has been implicated in regulating metabolic syndromes with anti-inflammatory function. However, the role of GPR120 in intestinal inflammation is unknown. Here, we investigated whether and how GPR120 regulates CD4+ T cell function to inhibit colitis development. METHODS: Dextran sodium sulfate (DSS)-induced colitis model, Citrobacter rodentium infection model, and CD4+ T cell adoptive transfer model were used to analyze the role of GPR120 in regulating colitis development. The effect of GPR120 on CD4+ T cell functions was analyzed by RNA sequencing, flow cytometry, and Seahorse metabolic assays. Mice were administered GPR120 agonist for investigating the potential of GPR120 agonist in preventing and treating colitis. RESULTS: Deficiency of GPR120 in CD4+ T cells resulted in more severe colitis in mice upon dextran sodium sulfate insult and enteric infection. Transfer of GPR120-deficient CD4+CD45Rbhi T cells induced more severe colitis in Rag-/- mice with lower intestinal interleukin (IL) 10+CD4+ T cells. Treatment with the GPR120 agonist CpdA promoted CD4+ T cell production of IL10 by up-regulating Blimp1 and enhancing glycolysis, which was regulated by mTOR. GPR120 agonist-treated wild-type, but not IL10-deficient and Blimp1-deficient, T helper 1 cells induced less severe colitis. Furthermore, oral administration of GPR120 agonist protected mice from intestinal inflammation in both prevention and treatment schemes. Gpr120 expression was positively correlated with Il10 expression in the human colonic mucosa, including patients with inflammatory bowel diseases. CONCLUSIONS: Our findings show the role of GPR120 in regulating intestinal CD4+ T cell production of IL10 to inhibit colitis development, which identifies GPR120 as a potential therapeutic target for treating inflammatory bowel diseases.

A Deep Learning-Based Algorithm for Identifying Precipitation Clouds Using Fengyun-4A Satellite Observation Data.

Rapid and accurate identification of precipitation clouds from satellite observations is essential for the research of quantitative precipitation estimation and precipitation nowcasting. In this study, we proposed a novel Convolutional Neural Network (CNN)-based algorithm for precipitation cloud identification (PCINet) in the daytime, nighttime, and nychthemeron. High spatiotemporal and multi-spectral information from the Fengyun-4A (FY-4A) satellite is utilized as the inputs, and a multi-scale structure and skip connection constraint strategy are presented in the framework of the algorithm to improve the precipitation cloud identification. Moreover, the effectiveness of visible/near-infrared spectral information in improving daytime precipitation cloud identification is explored. To evaluate this algorithm, we compare it with five other deep learning models used for image segmentation and perform qualitative and quantitative analyses of long-time series using data from 2021. In addition, two heavy precipitation events are selected to analyze the spatial distribution of precipitation cloud identification. Statistics and visualization of the experiment results show that the proposed model outperforms the baseline models in this task, and adding visible/near-infrared spectral information in the daytime can effectively improve model performance. More importantly, the proposed model can provide accurate and near-real-time results, which has important application in observing precipitation clouds.

ATF4 Deficiency Promotes Intestinal Inflammation in Mice by Reducing Uptake of Glutamine and Expression of Antimicrobial Peptides.

BACKGROUND & AIMS: Activating transcription factor 4 (ATF4) regulates genes involved in the inflammatory response, amino acid metabolism, autophagy, and endoplasmic reticulum stress. We investigated whether its activity is altered in patients with inflammatory bowel diseases (IBDs) and mice with enterocolitis. METHODS: We obtained biopsy samples during endoscopy from inflamed and/or uninflamed regions of the colon from 21 patients with active Crohn's disease (CD), 22 patients with active ulcerative colitis (UC), and 38 control individuals without IBD and of the ileum from 19 patients with active CD and 8 individuals without IBD in China. Mice with disruption of Atf4 specifically in intestinal epithelial cells (Atf4ΔIEC mice) and Atf4-floxed mice (controls) were given dextran sodium sulfate (DSS) to induce colitis. Some mice were given injections of recombinant defensin α1 (DEFA1) and supplementation of l-alanyl-glutamine or glutamine in drinking water. Human and mouse ileal and colon tissues were analyzed by quantitative real-time polymerase chain reaction, immunoblots, and immunohistochemistry. Serum and intestinal epithelial cell (IEC) amino acids were measured by high-performance liquid chromatography-tandem mass spectrometry. Levels of ATF4 were knocked down in IEC-18 cells with small interfering RNAs. Microbiomes were analyzed in ileal feces from mice by using 16S ribosomal DNA sequencing. RESULTS: Levels of ATF4 were significantly decreased in inflamed intestinal mucosa from patients with active CD or active UC compared with those from uninflamed regions or intestinal mucosa from control individuals. ATF4 was also decreased in colonic epithelia from mice with colitis vs mice without colitis. Atf4ΔIEC mice developed spontaneous enterocolitis and colitis of greater severity than control mice after administration of DSS. Atf4ΔIEC mice had decreased serum levels of glutamine and reduced levels of antimicrobial peptides, such as Defa1, Defa4, Defa5, Camp, and Lyz1, in ileal Paneth cells. Atf4ΔIEC mice had alterations in ileal microbiomes compared with control mice; these changes were reversed by administration of glutamine. Injections of DEFA1 reduced the severity of spontaneous enteritis and DSS-induced colitis in Atf4ΔIEC mice. We found that expression of solute carrier family 1 member 5 (SLC1A5), a glutamine transporter, was directly regulated by ATF4 in cell lines. Overexpression of SLC1A5 in IEC-18 or primary IEC cells increased glutamine uptake and expression of antimicrobial peptides. Knockdown of ATF4 in IEC-18 cells increased expression of inflammatory cytokines, whereas overexpression of SLC1A5 in the knockdown cells reduced cytokine expression. Levels of SLC1A5 were decreased in inflamed intestinal mucosa of patients with CD and UC and correlated with levels of ATF4. CONCLUSIONS: Levels of ATF4 are decreased in inflamed intestinal mucosa from patients with active CD or UC. In mice, ATF4 deficiency reduces glutamine uptake by intestinal epithelial cells and expression of antimicrobial peptides by decreasing transcription of Slc1a5. ATF4 might therefore be a target for the treatment of IBD.

Tripartite motif-containing (TRIM) 21 negatively regulates intestinal mucosal inflammation through inhibiting TH1/TH17 cell differentiation in patients with inflammatory bowel diseases.

BACKGROUND: Tripartite motif-containing (TRIM) 21 has been implicated in the pathogenesis of several types of autoimmune diseases. OBJECTIVE: We sought to elucidate TRIM21 expression in patients with inflammatory bowel diseases (IBDs) and its role in regulating intestinal mucosal inflammation. METHODS: TRIM21 expression was analyzed in the inflamed mucosa of patients with IBDs by means of quantitative RT-PCR and immunohistochemistry. Peripheral blood CD4+ T cells were transfected with lentivirus-expressing TRIM21 (LV-TRIM21) or LV-sh-TRIM21, and cytokine expression was determined by using quantitative RT-PCR and ELISA. TRIM21-/- mice were generated, and trinitrobenzene sulfonic acid- and CD45RBhighCD4+ T cell-induced colitis models were established to determine its role in induction of intestinal inflammation. RESULTS: TRIM21 was expressed predominantly in CD4+ T cells and decreased markedly in the inflamed mucosa of patients with IBDs compared with healthy control subjects. Ectopic expression of TRIM21 inhibited IBD CD4+ T cells to differentiate into TH1 and TH17 cells, whereas downregulation of TRIM21 had the opposite effects. TRIM21-/- mice had more severe colitis after administration of trinitrobenzene sulfonic acid compared with wild-type mice, which was characterized by increased expression of IFN-γ, TNF-α, and IL-17A in the colon. TRIM21-/-CD45RBhighCD4+ T cells reconstituted into recombination-activating gene (Rag1)-/- mice induced more severe colitis than in wild-type control mice. Mechanistically, interferon regulatory factor 3 was identified as a functional downstream target of TRIM21 in that silencing of interferon regulatory factor 3 suppressed TRIM21-/-CD4+ T-cell differentiation into TH1 and TH17 cells. CONCLUSIONS: TRIM21 plays a protective role in mucosal inflammation through inhibiting TH1 and TH17 cell differentiation. Thus TRIM21 might serve as a potential therapeutic target for the treatment of IBDs.

CD177+ neutrophils as functionally activated neutrophils negatively regulate IBD.

BACKGROUND: Neutrophils are accumulated in inflamed mucosa of IBD and play an important role in the pathogenesis. CD177 is expressed in neutrophils specifically and upregulated during inflammation. However, the role of CD177+ neutrophils in pathogenesis of IBD remains elusive. MATERIALS AND METHODS: Expression of CD177 was analysed in peripheral blood and intestinal mucosa from patients with IBD using quantitative RT-PCR, flow cytometry and immunohistochemistry. CD177+ and CD177- neutrophils were isolated to determine gene differences by RNA sequencing. Colitis was established in CD177-/- and wild-type mice in response to dextran sulfate sodium (DSS) insults to determine the role of CD177+ neutrophils in IBD. RESULTS: CD177+ neutrophils were markedly increased in peripheral blood and inflamed mucosa from patients with active IBD compared with healthy controls. RNA sequencing revealed that differential gene expression between CD177+ and CD177- neutrophils from patients with IBD was associated with response to bacterial defence, hydrogen peroxide and reactive oxygen species (ROS). CD177+ neutrophils produced lower levels of proinflammatory cytokines (ie, interferon-γ, interleukin (IL)-6, IL-17A), but higher levels of IL-22 and transforming growth factor-ß, and exhibited increased bactericidal activities (ie, ROS, antimicrobial peptides, neutrophil extracellular trap) compared with CD177- subset. CD177-/- mice developed more severe colitis on DSS insults compared with wild-type mice. Moreover, CD177 deficiency led to compromised intestinal barrier and impaired antibacterial immunity through decreased production of IL-22 by CD177- neutrophils. CONCLUSIONS: CD177+ neutrophils represent functionally activated population and play a protective role in IBD through increased bactericidal activity and IL-22 production. Targeting CD177+ neutrophils may be beneficial for treatment of IBD.

CD177+ neutrophils suppress epithelial cell tumourigenesis in colitis-associated cancer and predict good prognosis in colorectal cancer.

Neutrophils are found to be infiltrated in tumour tissues of patients with colitis-associated cancer (CAC) and colorectal cancer (CRC), and CD177 is mainly expressed in neutrophils. In our study, expression of CD177 in tumour tissues from patients with CAC or CRC was analysed byquantitative real-time polymerase chain reaction, flow cytometry and immunohistochemistry. We recruited 378 patients with CRC, determined CD177 expression in tumours and examined its correlation with clinicopathological features. Moreover, CAC model was induced in wild-type and CD177-/- mice by azoxymethane/dextran sodium sulphate. CD177+ neutrophils were significantly increased in colon tumour tissues from patients with CRC or CAC compared with controls. Expression of CD177 mRNA and percentages of CD177+ neutrophils were also markedly increased in tumour tissues from CRC patients compared with controls. Patients with high density of CD177+ neutrophils had better overall survival and disease-free survival compared with controls. Multivariate analyses revealed that the density of CD177+ neutrophils was an independent factor in predicting overall survival and disease-free survival. Consistently, CD177 depletion aggravated azoxymethane/dextran sodium sulphate-induced CAC in mice. Expression of Ki67 and proliferating cell nuclear antigen was increased in tumour tissues from CD177-/- mice compared with wild-type counterparts. Moreover, CD177-/- neutrophils failed to migrate in response to fMLP[AU: Please expand fMLP, DN, TNM and HIF-1α.] stimulation compared with wild-type controls. Our data indicate that CD177+ neutrophils suppress epithelial cell tumourigenesis and act as an independent factor in predicting the prognosis in patients with CRC. CD177+ neutrophils may serve as a novel therapeutic target in the treatment and predict the prognosis of CAC and CRC.

MicroRNA 301A Promotes Intestinal Inflammation and Colitis-Associated Cancer Development by Inhibiting BTG1.

BACKGROUND & AIMS: Intestinal tissues from patients with inflammatory bowel disease (IBD) and colorectal cancer have increased expression of microRNA-301a (MIR301A) compared with tissues from patients without IBD. We studied the mechanisms of MIR301A in the progression of IBD in human tissues and mice. METHODS: We isolated intestinal epithelial cells (IECs) from biopsy samples of the colon from 153 patients with different stages of IBD activity, 6 patients with colitis-associated cancer (CAC), and 35 healthy individuals (controls), enrolled in the study in Shanghai, China. We measured expression of MIR301A and BTG anti-proliferation factor 1 (BTG1) by IECs using quantitative reverse-transcription polymerase chain reaction. Human colon cancer cell lines (HCT-116 and SW480) were transfected with a lentivirus that expresses MIR301A; expression of cytokines and tight junction proteins were measured by quantitative reverse transcription polymerase chain reaction, flow cytometry, and immunofluorescence staining. We generated mice with disruption of the microRNA-301A gene (MIR301A-knockout mice), and also studied mice that express a transgene-encoding BTG1. Colitis was induced in knockout, transgenic, and control (C57BL/B6) mice by administration of dextran sulfate sodium (DSS), and mice were given azoxymethane to induce colorectal carcinogenesis. Colons were collected and analyzed histologically and by immunohistochemistry; tumor nodules were counted and tumor size was measured. SW480 cells expressing the MIR301A transgene were grown as xenograft tumors in nude mice. RESULTS: Expression of MIR301A increased in IECs from patients with IBD and CAC compared with controls. MIR301A-knockout mice were resistant to the development of colitis following administration of DSS; their colon tissues expressed lower levels of interleukin 1ß (IL1ß), IL6, IL8, and tumor necrosis factor than colons of control mice. Colon tissues from MIR301A-knockout mice had increased epithelial barrier integrity and formed fewer tumors following administration of azoxymethane than control mice. Human IECs expressing transgenic MIR301A down-regulated expression of cadherin 1 (also called E-cadherin or CDH1). We identified BTG1 mRNA as a target of MIR301A; levels of BTG1 mRNA were reduced in inflamed mucosa from patients with active IBD compared with controls. There was an inverse correlation between levels of BTG1 mRNA and levels of MIR301A in inflamed mucosal tissues from patients with active IBD. Human colon cancer cell lines that expressed a MIR301A transgene increased proliferation; they had increased permeability and decreased expression of CDH1 compared with cells transfected with a control vector, indicating reduced intestinal barrier function. BTG1 transgenic mice developed less severe colitis than control mice following administration of DSS. SW480 cells expressing anti-MIR301A formed fewer xenograft tumors in nude mice than cells expressing a control vector. CONCLUSIONS: Levels of MIR301A are increased in IECs from patients with active IBD. MIR301A reduces expression of BTG1 to reduce epithelial integrity and promote inflammation in mouse colon and promotes tumorigenesis. Strategies to decrease levels of MIR301A in colon tissues might be developed to treat patients with IBD and CAC.

Critical role of ROCK2 activity in facilitating mucosal CD4+ T cell activation in inflammatory bowel disease.

Rho-associated kinase (ROCK) has been found to be involved in the pathogenesis of a variety of autoimmune diseases, but the role of ROCK in inflammatory bowel disease (IBD) is still elusive. In this study, we demonstrated that the levels of ROCK2, but not ROCK1, activity were significantly upregulated in peripheral blood mononuclear cells (PBMC) and inflamed mucosa from IBD patients using a ROCK activity assay, and that ROCK2 activity in intestinal mucosa was positively correlated with disease severity. Stimulation with TNF markedly upregulated ROCK2 activity in IBD CD4+ T cells through NF-κB signaling. Blockade of ROCK2 activity using Slx-2119 significantly suppressed proinflammatory cytokines in inflamed mucosa from IBD patients including IFX-unresponsive CD patients, and inhibited IBD CD4+ T cells to differentiate into Th1 and Th17 cells through downregulating phosphorylated Stat1 and Stat3, but promoted Treg cell differentiation through upregulating phosphorylated Stat5. Furthermore, oral administration of Slx-2119 markedly ameliorated intestinal mucosal inflammation in TNBS-induced colitis in mice and decreased proinflammatory cytokines productions in inflamed colon. Our data indicate that ROCK2 plays a critical role in inducing mucosal T cell activation and inflammatory responses in IBD and that inhibition of ROCK2 activity might serve as a novel therapeutic approach in the management of IBD.

CD99 refers to the activity of inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD), composed of Crohn's disease (CD) and ulcerative colitis (UC), is an inflammatory autoimmune disease. CD99 has been reported to participate in migration of leukocytes and T cell activation. However, the roles of CD99 in IBD are obscure. MATERIALS AND METHODS: CD99 expression was examined in peripheral blood mononuclear cells (PBMCs) and inflamed mucosa from IBD patients by qRT-PCR. Serum TNF-α and IL-17A levels were detected by ELISA. Correlations of CD99 expression with TNF-α, IL-17A, Crohn's disease activity index (CDAI), simple endoscopic score for CD (SES-CD), Mayo index, and Truelove grading were performed by Pearson's correlation. RESULTS: CD99 expression was increased in PBMCs and inflamed mucosa from active CD and UC patients, and CD99 expression was also increased in the inflamed mucosa compared with unaffected control from the same patients. Serum TNF-α and IL-17A levels were increased in active CD or UC patients, and positively correlated with CD99 expression in PBMCs (CD: r = .402, p = .009; r = .350, p = .025. UC: r = .289, p = .028; r = .322, p = .014). Moreover, CD99 expression in inflamed mucosa was correlated with CDAI, SES-CD, Mayo index, and Truelove grading (r = .410, p = .012; r = .341, p = .005; r = .366, p = .002; r = .312, p = .011). CONCLUSION: CD99 expression is increased in patients with active IBD, and positively correlated with disease activity. Therefore, CD99 expression can be used as an index to evaluate the activity of IBD.

Critical Role of p53 and K-ras in the Diagnosis of Early Colorectal Cancer: a One-year, Single-center Analysis.

Background: Colorectal cancer (CRC) is strongly associated with colorectal polyps, which has become the third most common cancer in China. In the present study, we revealed the susceptible population and risk factors of colorectal polyps, and analyzed the expression of Ki-67, p53 and K-ras in the intestinal mucosa of patients with colorectal polyps in order to explore their significance in the detection and prognosis of CRC at an early stage. Materials and Methods: Total 801 cases of colorectal polyps were collected during endoscopic resection including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Expression of Ki-67, p53 and K-ras in the intestinal mucosa was detected by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Histological analysis was performed by Hematoxylin and eosin (HE) staining. Categorical variables were compared by one-way ANOVA, Pearson test, Spearman test, Kruskal-Wallis test and analysis of regression. Results: Of all patients with colorectal polyps, 90.76% of patients (n = 727) were ≥ 50 years old. 530 cases (66.17%) were males compared with 271 females (33.83%) in all 801 cases. More importantly, 1.03% patients (n = 7) underwent polypectomy and histological examination was confirmed to be the early stage of CRC. The expression of p53 was found to be significantly decreased, while K-ras was increased in tumor tissues of CRC compared with that in hyperplastic polyps and healthy controls. Conclusions: 1.03% patients (n = 7) underwent polypectomy was confirmed to be the early stage of CRC. Histological analysis for expression of p53 and K-ras can guarantee to screen the early stage of CRC.

Stromal Cell Regulation of Intestinal Inflammatory Fibrosis.

Intestinal inflammatory fibrosis is a severe consequence of inflammatory bowel diseases (IBDs). There is currently no cure for the treatment of intestinal fibrosis in IBD. Although inflammation is necessary for triggering fibrosis, the anti-inflammatory agents used to treat IBD are ineffective in preventing the progression of intestinal fibrosis and stricture formation once initiated, suggesting that inflammatory signals are not the sole drivers of fibrosis progression once it is established. Among multiple mechanisms involved in the initiation and progression of intestinal fibrosis in IBD, stromal cells play critical roles in mediating the process. In this review, we summarize recent progress on how stromal cells regulate intestinal fibrosis in IBD and how they are regulated by focusing on immune regulation and gut microbiota. We also outline the challenges moving forward in the field.

Microbial metabolite butyrate modulates granzyme B in tolerogenic IL-10 producing Th1 cells to regulate intestinal inflammation.

CD4+ T cells play a critical role in regulating autoimmune diseases, and intestinal microbial metabolites control various immune responses. Granzyme B (GzmB)-producing CD4+ T cells have been recently reported to participate in the pathogenesis of autoimmune diseases. Here, we found that GzmbB-deficient CD4+ T cells induced more severe colitis in Rag1-/- mice than wild-type (WT) CD4+ T cells. Germ-free (GF) mice exhibited a lower expression of GzmB in intestinal CD4+ T cells compared to specific pathogen-free (SPF) mice. Intestinal microbial metabolite butyrate increased GzmB expression in CD4+ T cells, especially in IL-10-producing Th1 cells, through HDAC inhibition and GPR43, but not GPR41 and GPR109a. Butyrate-treated GzmB-deficient CD4+ T cells demonstrated more severe colitis compared to butyrate-treated WT CD4+ T cells in the T cell transfer model. Butyrate altered intestinal microbiota composition, but altered microbiota did not mediate butyrate induction of intestinal CD4+ T cell expression of GzmB in mice. Blimp1 was involved in the butyrate induction of GzmB in IL-10-producing Th1 cells. Glucose metabolism, including glycolysis and pyruvate oxidation, mediated butyrate induction of GzmB in Th1 cells. In addition, we found that IKZF3 and NR2F6 regulated GzmB expression induced by butyrate. Together, our studies underscored the critical role of GzmB in mediating gut bacterial metabolite butyrate regulation of T cell tolerance at the mucosal surface.

CREB3L4 promotes hepatocellular carcinoma progression and decreases sorafenib chemosensitivity by promoting RHEB-mTORC1 signaling pathway.

This study was designed to explore the roles of CREB3L4 in the pathogenesis and drug resistance of hepatocellular carcinoma (HCC). The proliferation of HCC lines was determined in the presence of CREB3L4 over-expression and silencing. Chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter assay were performed to screen the potential target of CREB3L4 on mTORC1. Xenografted tumor model was established to define the regulatory effects of CREB3L4 in the tumorigenesis. Then we evaluated the roles of CREB3L4 in chemosensitivity to sorafenib treatment. CREB3L4 significantly induced the HCC cell proliferation by modulating the activation of mTROC1-S6K1 signaling pathway via binding with RHEB promoter. Moreover, CREB3L4 dramatically inhibited the chemosensitivity to sorafenib treatment via up-regulating RHEB-mTORC1 signaling. CREB3L4 promoted HCC progression and decreased its chemosensitivity to sorafenib through up-regulating RHEB-mTORC1 signaling pathway, indicating a potential treatment strategy for HCC through targeting CREB3L4.

Amelioration of NAFLD by sleeve gastrectomy-triggered hepatocyte regeneration in mice - experimental research.

BACKGROUND: Sleeve gastrectomy (SG) is known to alleviate non-alcoholic fatty liver disease (NAFLD) and restore liver function; however, its underlying mechanism remains unclear. MATERIALS AND METHODS: We investigated the effect of SG on the metabolic phenotype of diet-induced obese (DIO) mice. Postoperative stained liver images were analyzed to determine the hepatocyte proliferation phenotype. Single-cell RNA sequencing was used to characterize the regeneration signals of the liver after SG in DIO mice, and real-time quantitative reverse transcription PCR was performed to verify the above results. We employed Olink proteomics to capture serum element changes and investigated the role of Yes1 protein in liver regeneration and carcinogenesis through the Hippo-YAP pathway. DIO mice were treated with YAP inhibitor verteporfin after SG mice to clarify whether SG-induced liver regeneration is related to the YAP signaling pathway. RESULTS: SG significantly reduced NAFLD-associated dysfunction in hepatocytes and replaced them with fully functional hepatocytes, which have a high regenerative capacity across the entire liver. SG also enhanced the hepatic regenerative capacity, as demonstrated by SG combined with hepatic lobectomy in healthy mice. Yes1 protein was identified as the signaling molecule most closely related to classical regeneration signals. Our study showed that SG-enhanced proliferation and improved metabolism did not depend on YAP signaling. CONCLUSION: SG can enhance hepatic regenerative capacity and improve liver metabolism. This study provides a better understanding of the mechanisms underlying SG-induced metabolic improvements.

Novel subtype of obesity influencing the outcomes of sleeve gastrectomy: Familial aggregation of obesity.

BACKGROUND: Differences in the preoperative characteristics and weight loss outcomes after sleeve gastrectomy (SG) between patients with familial aggregation of obesity (FAO) and patients with sporadic obesity (SO) have not been elucidated. AIM: To explore the impact of SG on weight loss and the alleviation of obesity-related comorbidities in individuals with FAO. METHODS: A total of 193 patients with obesity who underwent SG were selected. Patients with FAO/SO were matched 1:1 by propensity score matching and were categorized into 4 groups based on the number of first-degree relatives with obesity (1SO vs 1FAO, 2SO vs 2FAO). The baseline characteristics, weight loss outcomes, prevalence of obesity-related comorbidities and incidence of major surgery-related complications were compared between groups. RESULTS: We defined FAO as the presence of two or more first-degree relatives with obesity. Patients with FAO did not initially show significant differences in baseline data, short-term postoperative weight loss, or obesity-related comorbidities when compared to patients with SO preoperatively. However, distinctions between the two groups became evident at the two-year mark, with statistically significant differences in both percentage of total weight loss (P = 0.006) and percentage of excess weight loss (P < 0.001). The FAO group exhibited weaker remission of type 2 diabetes mellitus (T2DM) (P = 0.031), hyperlipidemia (P = 0.012), and non-alcoholic fatty liver disease (NAFLD) (P = 0.003) as well as a lower incidence of acid reflux (P = 0.038). CONCLUSION: FAO patients is associated with decreased mid-to-long-term weight loss outcomes; the alleviation of T2DM, hyperlipidemia and NAFLD; and decreased incidence of acid reflux postoperatively.

[Treatment of Tile type C pelvic ring fracture using orthopedic robot combined with Starr pelvis reduction frame].

OBJECTIVE: To investigate the clinical effect of orthopedic robot combined with Starr pelvic reduction frame in the treatment of Tile type C pelvic ring fracture. METHODS: From October 2019 to May 2021, 14 patients with type C pelvic ring fracture were treated with robotic combined with Starr pelvic reduction frame, including 9 males and 5 females. The age ranged from 33 to 69 years. All the 14 patients had fresh closed fractures without femur, tibia and fibula fracture. Surgery was completed from 4 to 7 d after hospital admission. During the operation, the X-ray carbon bed was used, the pelvic ring was reduced by Starr pelvis reduction frame, and pelvic ring fracture was treated by orthopedic robot. Operation time, bleeding volume, fluoroscopy times of single screw placement, fracture reduction quality, affected limb function and complications were observed. Radiological reduction was evaluated using Matta scoring standard, and clinical efficacy was evaluated by Majeed pelvic function scoring system at the final follow-up. RESULTS: All of 14 patients successfully completed the operation, the operation time was 84 to 141 min, the bleeding volume was 20 to 50 ml, and the fluoroscopy times of single screw insertion was 4 to 9 times. All of 14 patients were followed up for 12 to 24 months. The healing time was 3 to 7 months. No complications such as fracture of internal fixation, screw loosening, infection and nerve injury were found. According to the evaluation criteria of Matta imaging reduction, 9 cases were excellent, 4 cases were good, and 1 case was fair. At the final follow-up, Majeed pelvic function scoring system was used:10 cases were excellent, 4 cases were good. CONCLUSION: The treatment of type C pelvic ring fracture with robotic combined Starr pelvis reduction frame is simple, time-saving, less trauma, less complications and effective.

"In-Out-In" Percutaneous Reduction Technique for Treatment of Valgus-Impacted Femoral Neck Fractures: A Technical Trick and Case Series.

OBJECTIVE: Valgus-impacted femoral neck fractures with or without posterior tilt of the femoral head are very common and full of pitfalls in clinical practice, which may lead to femoral neck shortening (FNS) and avascular necrosis (AVN). The study tries to introduce a novel technical trick aiming at anatomical reduction of valgus-impacted femoral neck fracture with minimally invasive procedure, and summarize the clinical prognosis in case series. METHODS: In this retrospective study, 24 patients (seven men and 17 women) with valgus-impacted femoral neck fractures between May 2017 and July 2020 were managed by "in-out-in" percutaneous reduction technique (percutaneous reduction group). Another 24 cases (10 men and 14 women) suffering the fractures underwent in situ fixation were enrolled as control group for function comparison (in situ fixation group). All patients were followed up for 24-42 months. The clinical outcomes included complications after operations (χ2 test) and Harris Hip Score (HHS) for hip function (unpaired t test) in the two groups. The radiographic outcomes were evaluated by collodiaphyseal angle, posterior tilt angle, and FNS before the operation and during the follow-up in the percutaneous reduction group (unpaired t test). RESULTS: Patients' preoperative data, including age, sex, affected side, fracture types, and medical history, were similar between the two groups, respectively (p > 0.05). After surgery, the mean HHS at 6, 12, and 24 months were all better in the percutaneous reduction group (76 ± 6.72, 85.34 ± 6.33 and 90.54 ± 5.81) than that in the in situ fixation group (70.86 ± 6.91, 80 ± 6.11 and 84.1 ± 7.82), respectively (p < 0.05). One patient suffered fixation failure with screws retreat and one patient suffered AVN in the percutaneous reduction group. In the in situ fixation group, AVN occurred in two patients at last follow-up. There was no significant difference in complication amounts between the two groups (p > 0.05). In the percutaneous reduction group, collodiaphyseal angle, posterior tilt angle, and amount of FNS were significantly different between preoperative cases and immediately postoperative cases (p < 0.05). However, there was no statistical difference of the measurements among postoperative cases at different time points (within 24 h, 6 months, and 2 years postoperatively) (p > 0.05). CONCLUSIONS: Our experience of the technique and the case series show that "in-out-in" percutaneous reduction technique for treatment of valgus-impacted femoral neck fracture with or without posterior tilt of the femoral head is safe and effective for achieving successful bone union and satisfactory function.