SENP3 senses oxidative stress to facilitate STING-dependent dendritic cell antitumor function.

STING-dependent cytosolic DNA sensing in dendritic cells (DCs) initiates antitumor immune responses, but how STING signaling is metabolically regulated in the tumor microenvironment remains unknown. Here, we show that oxidative stress is required for STING-induced DC antitumor function through a process that directs SUMO-specific protease 3 (SENP3) activity. DC-specific deletion of Senp3 drives tumor progression by blunting STING-dependent type-I interferon (IFN) signaling in DCs and dampening antitumor immune responses. DC-derived reactive oxygen species (ROS) trigger SENP3 accumulation and the SENP3-IFI204 interaction, thereby catalyzing IFI204 deSUMOylation and boosting STING signaling activation in mice. Consistently, SENP3 senses ROS to facilitate STING-dependent DC activity in tissue samples from colorectal cancer patients. Our results reveal that oxidative stress as a metabolic regulator promotes STING-mediated DC antitumor immune responses and highlights SENP3 as an overflow valve for STING signaling induction in the metabolically abnormal tumor microenvironment.

Ubc13 Promotes K63-Linked Polyubiquitination of NLRP3 to Activate Inflammasome.

NLRP3 inflammasome plays an important role in innate immune system through recognizing pathogenic microorganisms and danger-associated molecules. Deubiquitination of NLRP3 has been shown to be essential for its activation, yet the functions of Ubc13, the K63-linked specific ubiquitin-conjugating enzyme E2, in NLRP3 inflammasome activation are not known. In this study, we found that in mouse macrophages, Ubc13 knockdown or knockout dramatically impaired NLRP3 inflammasome activation. Catalytic activity is required for Ubc13 to control NLRP3 activation, and Ubc13 pharmacological inhibitor significantly attenuates NLRP3 inflammasome activation. Mechanistically, Ubc13 associates with NLRP3 and promotes its K63-linked polyubiquitination. Through mass spectrum and biochemical analysis, we identified lysine 565 and lysine 687 as theK63-linked polyubiquitination sites of NLRP3. Collectively, our data suggest that Ubc13 potentiates NLRP3 inflammasome activation via promoting site-specific K63-linked ubiquitination of NLRP3. Our study sheds light on mechanisms of NLRP3 inflammasome activation and identifies that targeting Ubc13 could be an effective therapeutic strategy for treating aberrant NLRP3 inflammasome activation-induced pathogenesis.

Berberine increases stromal production of Wnt molecules and activates Lgr5+ stem cells to promote epithelial restitution in experimental colitis.

BACKGROUND: Inflammatory bowel diseases (IBDs) are characterized by sustained inflammation and/or ulcers along the lower digestive tract, and have complications such as colorectal cancer and inflammation in other organs. The current treatments for IBDs, which affect 0.3% of the global population, mainly target immune cells and inflammatory cytokines with a success rate of less than 40%. RESULTS: Here we show that berberine, a natural plant product, is more effective than the frontline drug sulfasalazine in treating DSS (dextran sulfate sodium)-induced colitis in mice, and that berberine not only suppresses macrophage and granulocyte activation but also promotes epithelial restitution by activating Lgr5+ intestinal stem cells (ISCs). Mechanistically, berberine increases the expression of Wnt genes in resident mesenchymal stromal cells, an ISC niche, and inhibiting Wnt secretion diminishes the therapeutic effects of berberine. We further show that berberine controls the expression of many circadian rhythm genes in stromal cells, which in turn regulate the expression of Wnt molecules. CONCLUSIONS: Our findings suggest that berberine acts on the resident stromal cells and ISCs to promote epithelial repair in experimental colitis and that Wnt-ß-Catenin signaling may be a potential target for colitis treatment.

Cutting Edge: Inhibition of Glycogen Synthase Kinase 3 Activity Induces the Generation and Enhanced Suppressive Function of Human IL-10+ FOXP3+-Induced Regulatory T Cells.

IL-10 is critical for Foxp3+ regulatory T cell (Tregs)-mediated immune suppression, but how to efficiently upregulate IL-10 production in Tregs remains unclear. In this article, we show that human IL-10+ FOXP3+-induced regulatory T cell (iTreg) generation can be dramatically promoted by inhibiting GSK3 activity. IL-10+ FOXP3+ iTregs induced by GSK3 inhibition exhibit classical features of immune-suppressive T cells. We further demonstrate that IL-10+ iTregs exhibit enhanced suppressive function in both IL-10-dependent and -independent manners. The enhanced suppressive function of IL-10+ Tregs is not due to a single factor such as IL-10, although IL-10 may mediate this enhanced suppressive function to some extent. Mechanistically, the increased transcriptional activity of IL-10 promoter and the enhanced expression of C-Maf and BLIMP1 coordinately facilitate IL-10 expression in human iTregs under GSK3 inhibition. Our study provides a new strategy to generate human immune-suppressive IL-10+ FOXP3+ Tregs for immunotherapies.

Circulating miR-221/222 reduces CD4+ T cells by inhibiting CD4 expression in colorectal cancer.

Many patients with cancers have low levels of CD4+ in their peripheral blood. However, the molecular mechanism is still unclear. Here, we found that the blood levels of miR-221 and miR-222 were dramatically increased in patients with colorectal cancer (CRC), and both circulating miR-211 and miR-222 served as sensitive diagnostic markers with an area under the curve of 0.8790 and 0.9148, respectively. Transfection of either miR-221 or miR-222 resulted in the reduction of the surface CD4 antigen level but not the surface CD8 antigen level. The luciferase reporter assay showed that miR-221/222 directly regulated CD4 expression in human primary T cells. These data showed that miR-221/222 levels were upregulated in the blood of patients with CRC and that the expression of CD4 in human primary T cells was inhibited by miR-221/222. These findings provide a novel strategy for modulating the number of CD4+ T cells in the blood and further adjusting the microenvironment suitable for immunotherapy.

Infliximab for Crohn's Disease Patients with Perianal Fistulas: Better Image, Better Life.

BACKGROUND Patients with Crohn's disease (CD) experience physical impairments, poor quality of life and negative body image. These factors are exacerbated in CD patients with active perianal fistulas. MATERIAL AND METHODS Baseline characteristics were compared in retrospectively enrolled CD patients with and without active perianal fistulas. The relationships between improvements in perianal fistulas and quality of life, body image, and self-esteem were determined. The effects of infliximab treatment on improvement of psychological-social status were assessed in CD patients with active perianal fistulas. RESULTS Of the 301 CD patients included in our institution's database. 91 (30.2%) had active perianal fistulas. After adjustment by propensity score matching, CD patients with active perianal fistulas had lower self-esteem and more severe body image dissatisfaction than CD patients without active perianal fistulas (P<0.01 each). Perianal fistula response was closely associated with improvements in quality of life, body image dissatisfaction and self-esteem (P<0.01 each). Patients with perianal fistula treated with infliximab showed a response rate of 68.3%, significantly higher than the rate in patients with perianal fistula not treated with infliximab (P=0.005). Furthermore, improvements of life quality, body image and self-esteem were significantly greater in patients with perianal fistula who were than were not treated with infliximab (P<0.05 each). CONCLUSIONS CD patients with active perianal fistulas experience body image dissatisfaction, low self-esteem and poor quality of life. Treatment of these patients with infliximab could improve their body image, self-esteem and quality of life.

Chromogranin A: A Valuable Serum Diagnostic Marker for Non-Insulinoma Neuroendocrine Tumors of the Pancreas in a Chinese Population.

BACKGROUND Pancreatic neuroendocrine tumors (P-NETs) are uncommon neoplasms, with few studies to date assessing serum biomarkers for the diagnosis of P-NETs. This study assessed the ability of serum chromogranin A (CgA) concentrations to distinguish P-NETs from other pancreatic lesions in a Chinese population and to determine the histological grades of P-NETs. MATERIAL AND METHODS This prospective study enrolled 165 patients, including 73 with proven P-NETs, 60 with malignant tumors of the pancreas, and 32 with benign lesions of the pancreas. Serum CgA concentrations were measured by ELISA. RESULTS Serum CgA concentrations were significantly higher in patients with P-NET than in patients with other pancreatic malignancies and benign lesions (P<0.001), but did not differ significantly in the latter 2 groups (P=0.827). Serum CgA concentrations were significantly higher in patients with non-insulinoma P-NETs than in the other groups (P<0.001), but did not differ significantly in patients with insulinoma and patients with non-P-NETs (P=0.668). Receiver operating characteristic (ROC) curves revealed that a serum CgA concentration of 77.8 ng/ml could distinguish patients with non-insulinoma P-NETs from patients with non-P-NETs, with a sensitivity of 96.7%, a specificity of 76.1%, and an area under the ROC curve of 0.897. In patients with P-NETs, multifactor analysis showed that the non-insulinoma subtype and the presence of liver metastases were associated with elevated serum CgA (both p<0.001). CONCLUSIONS Serum CgA concentration may be a valuable diagnostic biomarker for non-insulinoma P-NETs. Elevated serum CgA is likely associated with liver metastases.

Identifying Potential Norovirus Epidemics in China via Internet Surveillance.

BACKGROUND: Norovirus is a common virus that causes acute gastroenteritis worldwide, but a monitoring system for norovirus is unavailable in China. OBJECTIVE: We aimed to identify norovirus epidemics through Internet surveillance and construct an appropriate model to predict potential norovirus infections. METHODS: The norovirus-related data of a selected outbreak in Jiaxing Municipality, Zhejiang Province of China, in 2014 were collected from immediate epidemiological investigation, and the Internet search volume, as indicated by the Baidu Index, was acquired from the Baidu search engine. All correlated search keywords in relation to norovirus were captured, screened, and composited to establish the composite Baidu Index at different time lags by Spearman rank correlation. The optimal model was chosen and possibly predicted maps in Zhejiang Province were presented by ArcGIS software. RESULTS: The combination of two vital keywords at a time lag of 1 day was ultimately identified as optimal (ρ=.924, P<.001). The exponential curve model was constructed to fit the trend of this epidemic, suggesting that a one-unit increase in the mean composite Baidu Index contributed to an increase of norovirus infections by 2.15 times during the outbreak. In addition to Jiaxing Municipality, Hangzhou Municipality might have had some potential epidemics in the study time from the predicted model. CONCLUSIONS: Although there are limitations with early warning and unavoidable biases, Internet surveillance may be still useful for the monitoring of norovirus epidemics when a monitoring system is unavailable.

MicroRNA-218 inhibits gastrointestinal stromal tumor cell and invasion by targeting KIT.

The objectives of this study were to detect the expressions of microRNA-218 (miR-218) in human gastrointestinal stromal tumor (GIST) tissues and cells and explore its effects on the biological features of GIST-T1 cells and the expression of its target gene KIT, so as to provide new insights for GIST treatment. Using quantitative real-time polymerase chain reaction (qRT-PCR), we detected the expressions of miR-218 in the tissues and adjacent tissues of GIST and in the GIST cell lines including GIST882, GIST430, GIST48, and GIST-T1. Forty-eight hours after the miR-218 mimic was transfected into the GIST-T1 cells, the expression of miR-218 in the GIST-T1 cells was detected by qRT-PCR. The effect of miR-218 on the GIST-T1 cell viability was detected using MTT. The effect of miR-218 on the proliferation and apoptosis of GIST-T1 cell was analyzed using flow cytometry. Transwell invasion chamber was applied to detect the effect of miR-218 on the invasion of GIST-T1 cells. KIT was identified to be a target gene of miR-218 by the luciferase reporter enzyme system, and the effect of miR-218 on the expression of KIT protein in cells was determined using Western blotting. As shown by qRT-PCR, compared with that in the GIST adjacent tissue, the expressions of miR-218 in the tumor tissue and GIST cell lines were significantly decreased (P < 0.0001). Compared with the control group, the expression of miR-218 increased significantly in GIST-T1 cells transfected with miR-218 mimic for 48 h (P < 0.01). MTT showed that the cell viability decreased significantly after the overexpression of miR-218 in the GIST-T1 cells (P < 0.01). Flow cytometry showed that the cell proliferation index significantly declined after the overexpression of miR-218 (P < 0.01); meanwhile, the apoptosis of cells also significantly increased (P < 0.01). Detection using the Transwell invasion chamber showed that the number of cells passing through the Transwell chamber significantly dropped after the enhanced expression of miR-218 (P < 0.01). Luciferase reporter gene assay showed that, compared with the control group, the relative luciferase activity significantly declined in the miR-218 mimic transfection group (P < 0.01). Compared with the control group, the expression of KIT protein in the GIST-T1 cells transfected with miR-218 mimic for 48 h significantly decreased (P < 0.01). In conclusion, the expression of miR-218 decreases in human GIST tissue and cell lines. miR-218 can negatively regulate the expression of KIT protein and inhibit the proliferation and invasion of GIST cells. Treatment based on the enhanced expression of miR-218 may be a promising strategy for GIST.

NLRP3 gene is associated with ulcerative colitis (UC), but not Crohn's disease (CD), in Chinese Han population.

OBJECTIVE: This study aimed to investigate whether NLRP3 is associated with IBD in Chinese Han population. METHODS: Three SNPs were genotyped using polymerase chain reaction with sequence-specific primers in 288 patients [232 Crohn's disease (CD) patients, 56 ulcerative colitis (UC) patients] and 274 controls. RESULTS: In IBD group, the results showed no significant association. When subdivided to CD and UC, it showed in CD subgroup, there was no significant association. However, in UC subgroup, rs10754558 (P allele=0.015272, P genotype=0.029776, OR [95% CI]=0.604190[0.401200-0.909886]) and rs10925019 (P allele=0.013042, P genotype=0.037045, OR [95% CI]=2.022613[1.149854-3.557812]) have significant associations with UC. The G and T alleles were risk factors of the susceptibility of UC, the GG and TT genotypes may increase risk of this disease. Rs4925648 has no association with UC. The haplotypes analysis results showed as follow: for rs4925648-rs10925019, CC and TT are risk factors for UC (for CC, χ2=3.605, P=0.057613, OR [95% CI]=1.645 [0.980-2.761], for TT, χ2=5.522, P=0.018804, OR [95% CI]=0.426[0.205-0.884]), and for rs10754558-rs10925019, CT and GC haplotypes are risk factors for UC (for CT, χ2=3.545, P=0.059739, OR [95% CI]=0.571[0.317-1.029], for GC, χ2=9.359, P=0.002228, OR [95% CI]=1.904 [1.255-2.887]). CONCLUSIONS: We first demonstrated that rs10754558 and rs10925019 are significantly associated with the susceptibility of UC, but not CD in Chinese Han population, suggesting that NLRP3 may play an important role in the pathogenesis of UC.

Heated and humidified CO2 pneumoperitoneum inhibits tumour cell proliferation, migration and invasion in colon cancer.

BACKGROUND: Peritoneal carcinomatosis (PC) arising from colorectal cancer is associated with poor prognosis and few treatment options are currently available. Laparoscopic CO2 insufflation stimulates the progression and metastatic potential of gastrointestinal carcinomas. However, heated and humidified CO2 pneumoperitoneum (HH-CO2) is a promising treatment for PC, although its effects and mechanism of action in human colon cancer cells remain unclear. This study evaluated the anti-tumour effects of HH-CO2 on human colon cancer in vitro. METHODS: Cell viability was assessed using the WST-8 assay in two colon cancer cell lines. Apoptosis was assessed by Annexin V PI flow cytometry, and migration and invasion were examined using wound healing and Transwell® invasion assays. The expressions of Bcl-2, Bax, matrix metalloproteinase-2 (MMP-2), E-cadherin, ICAM-1, and CD44 were detected by western blotting. RESULTS: HH-CO2 significantly inhibited cell proliferation, migration, invasion and adhesion. HH-CO2 induced apoptosis and significantly inhibited the expression of Bcl-2, MMP-2, ICAM-1 and CD44, and increased Bax and E-cadherin expression in colon cancer cells. CONCLUSIONS: HH-CO2 induces apoptosis and inhibits proliferation, migration, invasion and adhesion of human colon cancer cells. Our results suggest that HH-CO2 may serve as a potential candidate for the treatment and/or prevention of peritoneal carcinomatosis from colorectal cancer and warrant further in vivo investigation.

A Natural Peptide from A Traditional Chinese Medicine Has the Potential to Treat Chronic Atrophic Gastritis by Activating Gastric Stem Cells.

Chronic atrophic gastritis (AG) is initiated mainly by Helicobacter pylori infection, which may progress to stomach cancer following the Correa's cascade. The current treatment regimen is H. pylori eradication, yet evidence is lacking that this treatment is effective on later stages of AG especially gastric gland atrophy. Here, using AG mouse model, patient samples, gastric organoids, and lineage tracing, this study unraveled gastric stem cell (GSC) defect as a crucial pathogenic factor in AG in mouse and human. Moreover, a natural peptide is isolated from a traditional Chinese medicine that activated GSCs to regenerate gastric epithelia in experimental AG models and revitalized the atrophic gastric organoids derived from patients. It is further shown that the peptide exerts its functions by stabilizing the EGF-EGFR complex and specifically activating the downstream ERK and Stat1 signaling. Overall, these findings advance the understanding of AG pathogenesis and open a new avenue for AG treatment.

TMED4 facilitates Treg suppressive function via ROS homeostasis in tumor and autoimmune mouse models.

Endoplasmic reticulum stress (ERS) plays crucial roles in maintaining regulatory T cells (Treg) stability and function, yet the underlying mechanism remains largely unexplored. Here we demonstrate that ERS-related protein transmembrane p24 trafficking protein 4 (TMED4) Treg-specific knockout (Tmed4ΔTreg) mice contain more Treg cells with impaired Foxp3 stability, Treg signature and suppressive activity, which leads to T cell hyperactivation, exacerbated inflammatory phenotype and boosted anti-tumor immunity in mice. Mechanistically, loss of Tmed4 causes defects in ERS and nuclear factor erythroid 2-related factor 2 (NRF2)-related antioxidant response, which results in excessive reactive oxygen species (ROS) that reduces Foxp3 stability and suppressive function of Treg cells in an IRE1α-XBP1 axis-dependent manner. The abnormalities can be effectively rescued by ROS scavenger, NRF2 inducer or forcible expression of IRE1α. Moreover, TMED4 suppresses IRE1α proteosome degradation via the ER-associated degradation (ERAD) system including BIP. Our study reveals that TMED4 maintains Treg cell stability and suppressive function through IRE1α-dependent ROS and the NRF2-related antioxidant response.

Downregulation of gas5 increases pancreatic cancer cell proliferation by regulating CDK6.

Recent studies have revealed that long non-coding RNAs (lncRNAs) play important roles in cancer biology and that lncRNA gas5 (growth arrest-specific 5) regulates breast cancer cell growth. However, the role of gas5 in pancreatic cancer progression remains largely unknown. In the current study, we assay the expression level of gas5 in pancreatic cancer tissues and define the role of gas5 in the regulation of pancreatic cancer cell proliferation. We verify that the expression level of gas5 is significantly decreased in pancreatic cancer tissues compared with normal control. Overexpression of gas5 in pancreatic cancer cells inhibits cell proliferation, whereas gas5 inhibition induces a significant decrease in G0/G1 phase and an increase in S phase. We further demonstrate that gas5 negatively regulates CDK6 (cyclin-dependent kinase 6) expression in vitro and in vivo. More importantly, knockdown of CDK6 partially abrogates gas5-siRNA-induced cell proliferation. These data suggest an important role of gas5 in the molecular etiology of pancreatic cancer and implicate the potential application of gas5 in pancreatic cancer therapy.

Clinical significance of RECK promoter methylation in pancreatic ductal adenocarcinoma.

The aim of this study was to analyze the clinical significance of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) promoter methylation in pancreatic ductal adenocarcinoma (PDA). Methylation-specific polymerase chain reaction was used to examine the promoter methylation status of RECK in 60 pairs of PDA tissue samples and adjacent non-cancerous tissue samples. Statistical analyses were applied to test the associations between RECK promoter methylation status, clinicopathologic factors, and prognosis. The rate of RECK promoter methylation was significantly higher in PDA tissues than in adjacent non-cancerous tissues (P < 0.001). RECK methylation status was significantly associated with clinical stage (P = 0.017), histological differentiation (P = 0.046), and lymph node metastasis (P = 0.003), but was not associated with gender, age, and tumor location (all P > 0.05). Additionally, RECK promoter methylation is associated with malignant behavior and poor prognosis. In conclusion, determination of RECK promoter methylation status in tumor tissues may assist in the identification of patients who require aggressive postoperative intervention in order to improve prognosis.

Preoperative Prognostic Nutritional Index and Nomogram for Predicting the Risk of Postoperative Complications in Patients With Crohn's Disease.

INTRODUCTION: Patients with Crohn's disease (CD) are at a high risk of having postoperative complications. Preoperative prognostic nutritional index (PNI) has been extensively studied for postoperative complications in malignancies but seldom for CD. METHODS: Patients who underwent CD-related bowel surgery for the first time in our hospital were retrospectively enrolled from January 2013 to October 2019. Differences in clinical features in low-PNI (≤34) and high-PNI (>34) groups were compared. A prognostic nomogram was then established to explore the risk factors and their assignments of postoperative complications. RESULTS: A total of 124 patients who underwent CD-related bowel surgery in our hospital from January 2013 to October 2019 were enrolled. Of these patients, 39 (31.5%) were categorized in the low-PNI group. The serum albumin levels (23.4 ± 4.8 vs 35.8 ± 5.2 g/L, P < 0.001), hemoglobin levels (98.0 ± 24.1 vs 115.8 ± 22.2 g/L, P < 0.001), and white blood cell counts (8.3 ± 5.4 × 10 9 vs 6.3 ± 3.0 × 10 9 , P = 0.009) of the patients in the low-PNI group were lower than those in the high-PNI group. Postoperative complications were observed in 35 cases of the total cohort, 20 of 39 (51.3%) in the low-PNI group, and 15 of 85 (17.6%) in the high-PNI group ( P < 0.001). A prognostic nomogram was built through least absolute shrinkage and selection operator regression. The nomogram revealed a significant difference in the length of postoperative stay between patients with high-risk postoperative complications and those with low-risk postoperative complications (17.07 ± 24.73 vs 10.36 ± 4.51, P = 0.02). DISCUSSION: PNI is closely associated with postoperative complications in patients with CD. Its inclusion in a prognostic nomogram provides a convenient mechanism to predict postoperative complications in patients with CD undergoing surgery.

Analysis and purification of innate lymphoid cells in human intestine and blood by flow cytometry.

The role of innate lymphoid cells (ILCs)-including natural killer cells, helper-like ILC1s, ILC2s, ILC3s, and lymphoid tissue inducers-in human cancer is still poorly understood due to the scarcity of cell number. To address this, we present a protocol to analyze or purify ILCs from human blood, adjacent intestine, and colorectal tumor tissue. We describe steps for tissue and blood treatment, density centrifugation, antibody staining, and cell sorting. For complete details on the use and execution of this protocol, please refer to Qi et al. (2021).1.

Novel mRNA Signature for Anti-TNF-α Therapy Primary Response in Patients With Ulcerative Colitis.

BACKGROUND: Ulcerative colitis (UC), an idiopathic, chronic inflammatory disorder of the colonic mucosa, is commonly treated with antitumor necrosis factor α (anti-TNF-α) agents. However, only approximately two-thirds have an initial response to these therapies. METHODS: We integrated gene expression profiling from 3 independent data sets of 79 UC patients before they began anti-TNF-α therapy and calculated the differentially expressed genes between patient response and nonresponse to anti-TNF-α therapy and developed a de novo response-associated transcription signature score (logOR_Score) to demonstrate the predictive capability of anti-TNF-α therapy for therapeutic efficacy. Furthermore, we performed association analysis of the logOR_Score and clinical features, such as disease activity and immune microenvironment. RESULTS: A total of 2522 responsive and 1824 nonresponsive genes were identified from the integrated data set. Responsive genes were significantly enriched in metabolism-related pathways, whereas nonresponsive ones were associated with immune response-related pathways. The logOR_Score enabled the accurate prediction of the therapeutic efficacy of anti-TNF-α in 4 independent patient cohorts and outperformed the predictions made based on 6 transcriptome-based signatures. In terms of clinical features, the logOR_Score correlated highly with the activity of UC. From an immune microenvironment perspective, logOR_Scores of CD8+IL-17+ T cells, follicular B cells, and innate lymphoid cells significantly decreased in inflamed UC tissue. CONCLUSIONS: The de novo response-associated transcription signature may provide novel insights into the personalized treatment of patients with UC. Comprehensive analyses of the response-related subtypes and the association between logOR_Score and clinical features and immune microenvironment may provide insights into the underlying UC pathogenesis.

We developed a de novo response-associated transcription signature score (logOR_Score) to predict the response of patients with UC to anti-TNF-α agents prior to treatment and explored the different response mechanisms of UC.

Ubiquitin-specific protease 47 regulates intestinal inflammation through deubiquitination of TRAF6 in epithelial cells.

Deubiquitinates (DUBs) alter the stabilities, localizations or activities of substrates by removing their ubiquitin conjugates, which are closely related to the development of inflammatory response. Here, we show that ubiquitin-specific protease 47 (USP47) prevents inflammation development in inflammatory bowel disease (IBD). Compared with wild-type mice, Usp47 knockout mice are more susceptible to dextran sodium sulfate (DSS)-induced acute and chronic colitis with higher inflammatory cytokines expression and severe intestinal tissue damage. Chimeric mouse experiments suggest that non-hematopoietic cells mainly contribute to the phenotype. And, DSS-induced colitis of the Usp47 knockout mice depends on commensal bacteria. Mechanistically, down-regulation of USP47 aggravates the activation of NF-κB signaling pathway by increasing the K63-linked poly-ubiquitination of tumor necrosis factor receptor-associated factor 6 (TRAF6) in intestinal epithelial cells. Furthermore, the expression of USP47, negatively correlated with the degree of inflammation, is lower at colonic inflammatory lesions than that non-inflammatory sites from the intestine from ulcerative colitis (UC) and Crohn's disease (CD) patients. These data, taken together, indicate that USP47 regulates intestinal inflammation through de-ubiquitination of K63-linked poly-ubiquitination TRAF6 in intestinal epithelial cells.

Oral zero-valent-molybdenum nanodots for inflammatory bowel disease therapy.

Inflammatory bowel disease (IBD) affects millions of people each year. The overproduction of reactive oxygen species (ROS) plays a critical role in the progress of IBD and will be a potential therapeutic target. Here, we synthesize a kind of oral zero-valent-molybdenum nanodots (ZVMNs) for the treatment of IBD by scavenging ROS. These ultrasmall ZVMNs can successfully pass through the gastric acid and then be absorbed by the intestine. It has been verified that ZVMNs can down-regulate the quantity of ROS and reduce colitis in a mouse IBD model without distinct side effects. In addition, RNA sequencing reveals a further mechanism that the ZVMNs can protect colon tissues from oxidative stress by inhibiting the nuclear factor κB signaling pathway and reducing the production of excessive pro-inflammatory factors. Together, the ZVMNs will offer a promising alternative treatment option for patients suffering from IBD.