The Potential of Vitamin D3 to Repaired Mucosal Injury in Dextran Sulfate Sodium Induced Acute Colitis in Mice

BACKGROUND: Inflammatory Bowel Disease (IBD) has become an emerging disease worldwide. The treatment of IBD involves two basic principles: Inflammation control and mucosal repair. AIM: This study evaluates the potential effect of Vitamin D3 in mucosal repair through colon stem cell activation and proliferation. METHODS: Dextran sulfate sodium (DSS; 5%) was used to induce colitis in mice. Vitamin D3 at various dosages was then administered as a treatment. The mice were divided into five groups: Control (C-); DSS only (C+); and DSS (5%) plus Vitamin D3 at 0.2 μg (VD1), 0.4 μg (VD2), or 0.6 μg (VD3) per 25 g body weight as the treatment groups. Immunofluorescence analyses of Lgr5+ expression indicated stem cell activation, and Ki67 expression indicated stem cell proliferation. The disease activity index (DAI), colon length, and histopathological index scores were determined after treatment to assess the inflammation and severity of colitis. RESULTS: Immunofluorescence analyses showed a gradually increasing expression of Lgr5+ also Ki67 in proportion with high doses group of Vitamin D3 (p < 0.05). The colon length, DAI scores, and histopathological index scores improved in all groups after Vitamin D3 treatment (p = 0.05; p = 0.026; and p = 0.029, respectively). CONCLUSION: Vitamin D3 has a potential beneficial effect on amplifying intestinal stem cells regulated by Wnt/B-catenin signaling. It is also reduced the inflammatory process proved by the evaluation severity of colitis. It might play an essential role in mucosal repair in IBD.

CD147 receptor is essential for TFF3-mediated signaling regulating colorectal cancer progression

Major gaps in understanding the molecular mechanisms of colorectal cancer (CRC) progression and intestinal mucosal repair have hampered therapeutic development for gastrointestinal disorders. Trefoil factor 3 (TFF3) has been reported to be involved in CRC progression and intestinal mucosal repair; however, how TFF3 drives tumors to become more aggressive or metastatic and how TFF3 promotes intestinal mucosal repair are still poorly understood. Here, we found that the upregulated TFF3 in CRC predicted a worse overall survival rate. TFF3 deficiency impaired mucosal restitution and adenocarcinogenesis. CD147, a membrane protein, was identified as a binding partner for TFF3. Via binding to CD147, TFF3 enhanced CD147-CD44s interaction, resulting in signal transducer and activator of transcription 3 (STAT3) activation and prostaglandin G/H synthase 2 (PTGS2) expression, which were indispensable for TFF3-induced migration, proliferation, and invasion. PTGS2-derived PGE2 bound to prostaglandin E2 receptor EP4 subtype (PTGER4) and contributed to TFF3-stimulated CRC progression. Solution NMR studies of the TFF3-CD147 interaction revealed the key residues critical for TFF3 binding and the induction of PTGS2 expression. The ability of TFF3 to enhance mucosal restitution was weakened by a PTGS2 inhibitor. Blockade of TFF3-CD147 signaling using competitive inhibitory antibodies or a PTGS2 inhibitor reduced CRC lung metastasis in mice. Our findings bring strong evidence that CD147 is a novel receptor for TFF3 and PTGS2 signaling is critical for TFF3-induced mucosal restitution and CRC progression, which widens and deepens the understanding of the molecular function of trefoil factors.

ZINC40099027 Promotes Gastric Mucosal Repair in Ongoing Aspirin-Associated Gastric Injury by Activating Focal Adhesion Kinase

Nonsteroidal anti-inflammatory drugs cause gastric ulcers and gastritis. No drug that treats GI injury directly stimulates mucosal healing. ZINC40099027 (ZN27) activates focal adhesion kinase (FAK) and heals acute indomethacin-induced small bowel injury. We investigated the efficacy of ZN27 in rat and human gastric epithelial cells and ongoing aspirin-associated gastric injury. ZN27 (10 nM) stimulated FAK activation and wound closure in rat and human gastric cell lines. C57BL/6J mice were treated with 300 mg/kg/day aspirin for five days to induce ongoing gastric injury. One day after the initial injury, mice received 900 µg/kg/6 h ZN27, 10 mg/kg/day omeprazole, or 900 µg/kg/6 h ZN27 plus 10 mg/kg/day omeprazole. Like omeprazole, ZN27 reduced gastric injury vs. vehicle controls. ZN27-treated mice displayed better gastric architecture, with thicker mucosa and less hyperemia, inflammation, and submucosal edema, and lost less weight than vehicle controls. Gastric pH, serum creatinine, serum alanine aminotransferase (ALT), and renal and hepatic histology were unaffected by ZN27. Blinded scoring of pFAK-Y-397 immunoreactivity at the edge of ZN27-treated lesions demonstrated increased FAK activation, compared to vehicle-treated lesions, confirming target activation in vivo. These results suggest that ZN27 ameliorates ongoing aspirin-associated gastric mucosal injury by a pathway involving FAK activation. ZN27-derivatives may be useful to promote gastric mucosal repair.

Danggui Buxue Decoction Ameliorates Inflammatory Bowel Disease by Improving Inflammation and Rebuilding Intestinal Mucosal Barrier

Objective. This study aimed to determine whether Danggui Buxue decoction (DGBX) can improve inflammatory bowel disease (IBD) by regulating immunity and promoting intestinal mucosal repair. Method. Dextran sulfate sodium (DSS) was used to induce the IBD model. Drugs (DGBX or saline) were administered to mice, which were randomly divided into three groups (control, model, and experimental groups). Hematoxylin and eosin staining of intestinal tissues was conducted to observe for morphological changes. Changes in cytokines and immune cells in the intestinal tissues were detected by enzyme-linked immunosorbent assay and flow cytometry. Immunofluorescence techniques were used to assess the status of the intestinal mucosal repair. Results. This study found that treatment with DGBX can effectively improve the inflammatory state and pathological structure of the IBD model. DGBX not only can significantly change the composition of intestinal mucosal immune cells and promote the regression of inflammation but also significantly increase the proliferation of intestinal epithelial cells and promote the rapid repair of intestinal mucosal barrier injury compared with the model group ( p < 0.05 ). Conclusion. Taking these results, DGBX shows promising protective effects on IBD by regulating immunity and promoting intestinal mucosal repair.

THE TIGHT JUNCTION PROTEIN ZO-1 REGULATES MITOTIC SPINDLE ORIENTATION TO ENABLE EFFICIENT MUCOSAL REPAIR

The intestinal damage can be caused by physical, infectious, and immune-mediated injury. Rapid repair, which is essential for a return to mucosal homeostasis, depends on rapid epithelial migration, i.e., restitution, as well as epithelial proliferation and differentiation. Barrier restoration is a critical component of this repair process, but the contributions of structural proteins that form the barrier to mucosal repair have not been defined. Aim: To determine the contributions of the intestinal epithelial tight junction protein zonula occludens-1 (ZO-1) to mucosal repair. Results: Intestinal epithelial ZO-1 transcript and protein expression are reduced in biopsies from inflammatory bowel disease (IBD) patients relative to healthy controls. To determine if this ZO-1 loss contributes to disease pathogenesis, we created intestinal epithelial ZO-1-deficient Tjp1f/f x villin-Cre+ mice. When stressed, for example, with 2% DSS, ZO-1-deficient mice displayed much greater mucosal damage and weight loss relative to ZO-1-sufficient mice and failed to recover fully, even 4 weeks after DSS discontinuation. To better define the defect, mice were injected with nucleoside analogs (BrdU and EdU) to label proliferating cells 1 and 3 days after DSS discontinuation. When assessed 2 hours after labeling, numbers of labeled nuclei were significantly reduced in ZO-1-deficient mice relative to ZO-1-sufficient mice. More striking, however, was the nuclear fragmentation and staining for cleaved caspase-3 at 24 hours after labeling. In vitro studies of colonoids were used to better define the mechanisms of epithelial loss. Colonoids from ZO-1-deficient mice were smaller, had reduced numbers of buds (crypt domains) and Lgr5+ stem cells, and were nonresponsive to enhanced Wnt signaling induced by the GSK3 inhibitor CHIR99021, relative to ZO-1-sufficient colonoids. Live imaging of mitosis showed misoriented mitotic spindles in ZO-1-deficient colonoids that caused one daughter cell to lose contact with the extracellular matrix. Misoriented mitotic spindles were also present in tissues from DSS-treated ZO-1-deficient, not ZO-1-sufficient, mice. Live imaging of colonoids from mRFP1-ZO-1 transgenic mice detected transient accumulation of ZO-1 at the cleavage furrow, suggesting that ZO-1 interactions at this site required for accurate mitotic spindle orientation. Conclusion: ZO-1 has a previously unappreciated, noncanonical function in mitotic spindle orientation that is independent of barrier maintenance but central to epithelial proliferation and repair. We postulate that, in the absence of ZO-1, loss of contact with the basement membrane leads to anoikis, i.e., detachment-induced apoptosis, and an abortive proliferative response that compromises repair. We speculate that ZO-1 downregulation in IBD may similarly interfere with mucosal healing. Support: NIH (DK068271, DK061931)

Trefoil Factor Family Member 2 (TFF2) as an Inflammatory-Induced and Anti-Inflammatory Tissue Repair Factor

Trefoil factor family member 2 (TFF2) is known for its involvement in mucosal repair. Whereas it is overexpressed during inflammatory processes, adding TFF2 leads to an anti-inflammatory effect that would contribute to create the microenvironment required for tissue repair. These properties present TFF2 with a homeostatic pattern during inflammatory processes as illustrated by selected examples.