Mucosal Apoptosis Research Articles

P53 upregulated by HIF-1α promotes gastric mucosal epithelial cells apoptosis in portal hypertensive gastropathy.

Portal hypertensive gastropathy (PHG) is a serious complication of liver cirrhosis and a potential cause of gastrointestinal bleeding. Mucosal apoptosis is an essential pathological feature of PHG. However, whether HIF-1α and p53 are involved in mucosal apoptosis and whether HIF-1α induces PHG by mediating p53 remains unclear. Gastric mucosal injury and apoptosis were examined in PHG patients and animal models. The mechanisms of HIF-1α- and p53-mediated apoptosis were analyzed. The GES-1 cell line was used to elucidate the underlying mechanisms using siRNA knockdown of HIF-1α and p53 in a hypoxic environment in vitro. Epithelial apoptosis, HIF-1α, and p53 were markedly induced in the gastric mucosa of PHG. Apoptosis was attenuated in mice with HIF-1α- and p53-specific inhibitors. Apoptotic signaling factors were markedly induced in the gastric mucosa of PHG. Inhibition of p53 demonstrably attenuated the mucosal apoptosis; however, it did not affect HIF-1α expression. Conversely, targeted deletion of HIF-1α significantly inhibited p53 expression and attenuated the injury and p53-mediated apoptosis. Bax and Bcl-2 expression can be upregulated and downregulated by p53, respectively, to increasecleaved caspase-3 expression, which can be regulated by HIF-1α. These results indicate that HIF-1α regulates the p53-induced mucosal epithelial apoptotic signaling pathway and that HIF-1α and p53 are potential therapeutic targets for PHG.

Oridonin attenuates dextran sulfate sodium‑induced ulcerative colitis in mice via the Sirt1/NF‑κB/p53 pathway.

Ulcerative colitis (UC) is a serious chronic inflammatory bowel disease. Oridonin (Ori) has anti-inflammatory, antibacterial and antitumor activities. The current study aimed to investigate the regulatory role of Ori in UC. BALB/C mice were induced to form a model of UC using dextran sulfate sodium (DSS), after which UC mice received high-(Ori-H) and low-doses of Ori (Ori-L). Subsequently, the length of the colon was measured and hematoxylin and, eosin staining was performed to detect colonic injury. Western blot analysis was performed to detect expression level in tight junction-associated proteins in murine colon tissue. Additionally, myeloperoxidase activity and inflammatory factor concentration were detected in colon tissue using ELISA. TUNEL and western blot assays were also performed to detect cell apoptosis, and the expression level of Sirt1/NF-κB/p53 pathway-related proteins was also determined using western blot analysis. The results revealed that Ori ameliorated clinical symptoms and pathological lesions in mice with DSS-induced UC. Furthermore, Ori protected the integrity of the colonic mucosal barrier, reduced the inflammatory response and decreased oxidative stress levels in mice with DSS-induced UC. Ori treatment also inhibited intestinal mucosal cell apoptosis. These effects may have occurred via the Sirtuin-1/NF-κB/p53 pathway. In conclusion, Ori treatment inhibited DSS-induced inflammatory response, oxidative stress and intestinal mucosal apoptosis in UC mice.

Inflection-Point Nutrition Support Determined by Oral Mucosal Apoptosis Rate Is a Novel Assessment Strategy for Personalized Nutrition: A Prospective Cohort Study.

Background: Energy intake and nutritional status influences a patient’s recovery from major abdominal surgery. The aim of this study is to explore and validate the clinical feasibility of an inflection-point nutrition strategy for personalized nutrition in gastric cancer patients after surgery. Methods: We conducted a prospective cohort study from a single tertiary referral hospital. Patients diagnosed with gastric cancer who met the inclusion criteria were included in this study. We collected the demographic and clinic pathological characteristics of included patients. Patients were divided into a formular nutrition (FN) and inflection-point nutrition (IPN) group. We monitored the perioperative dynamics of the oral mucosal epithelia cell apoptosis rate. Predictive factors for inflection phenomenon were investigated in univariate and multivariate analysis. Results: A total of 53 gastric cancer patients were included. A total of 30 (56.6%) patients showed the inflection phenomenon, with 9 (34.6%) patients in the FN group and 21 (77.8%) patients in the IPN group, respectively. We found that patients with the inflection phenomenon had a shorter duration of hospital stay compared to patients without the inflection phenomenon (p = 0.04). In multivariate analysis, independent predictive factors for inflection phenomenon were age (p = 0.015), operation time ≤ 300 min (p = 0.012), and average energy intake ≥ 25 Kcal/kg/day (p = 0.038). Conclusions: Our findings for the first time revealed that the oral epithelial cell apoptosis rate can promptly reflect the patients’ perioperative nutrition needs. Meanwhile, we developing a novel and feasible nutrition therapy guided by the oral epithelial cell apoptosis rate is novel in gastric cancer patients that have undergone laparoscopic gastrectomy.

Phase II trial of moderate dose omega-3 acid ethyl esters for colorectal cancer prevention in patients with lynch syndrome (COLYNE).

TPS209 Background: Lynch syndrome (LS) is the most common inherited colorectal cancer (CRC) syndrome and is responsible for about 3% of newly diagnosed CRC. It is caused by germline mutations in one of the DNA mismatch repair (MMR) genes, and patients with LS carry a lifetime risk of CRC ranging between 10% and 70%. The role of inflammation in driving this malignant transformation is now well established and retrospective studies have revealed a potential chemo-preventative role for omega-3 (ω-3) polyunsaturated fatty acids (PUFAs), possibly via inhibition of inflammatory pathways associated with the development of defective MMR CRC tumors. While patients with LS have the highest risk of developing CRC, the majority of chemoprevention trials are focused on sporadic CRC. Effective interventions to reduce the risk of developing CRC in this population are limited to close surveillance and surgical prophylaxis. There is an unmet need for safe, effective, and non-invasive chemo-preventive interventions in patients with LS. Methods: This pilot study is a single-arm, open-label, phase 2 clinical trial of omega-3 acid ethyl esters (generic Lovasa; 2 grams orally once daily) for adult patients (≥ 18 years of age) with confirmed LS (based on germline testing of the MMR genes panel: MLH1, MSH2, MSHS6, PMS2 or deletion in EPCAM gene). Patients who are not candidate for elective endoscopy and/or with prior history of right sided or pan-colectomy are excluded. Thirty-four patients are expected to enroll, with a primary objective to determine the feasibility (defined as 80% retention rate) of 12 months of treatment with 2 grams capsules of omega-3 acid ethyl esters daily. Secondary endpoints include safety and tolerability of the intervention. Correlative aims include pre and post treatment assessment of colon mucosal tissue proliferation (right sided colon specimens will be evaluated for markers of proliferation (Ki-67) and apoptosis (Caspase-3)), the effect of omega-3 acid ethyl esters on inflammatory markers in serum, urine and feces (PGE-2, COX-2, β-catenin levels, and EPA:AA ratios), and gene expression related to proliferation, apoptosis and cell survival in colon tissue (NF-κB/Wnt pathways). The impact of omega-3 acid ethyl esters on intestinal microbiota will also be assessed (16S rRNA-based profiling). Correlative Colon tissue, serum, urine and feces samples are collected at baseline and at 12 months. The study is actively enrolling with 20 patients enrolled at the time of submission. Clinical trial information: NCT03831698.

Effect of Anti-TNF Therapy on Mucosal Apoptosis Genes Expression in Crohn's Disease.

Crohn's disease (CD) is a chronic immune-mediated disorder for which there is not a fully effective treatment. Moreover, biological therapy with anti-tumor necrosis factor-α (anti-TNF-α) monoclonal antibodies leads to an effective response in only 60–70% of patients. Our previous data suggested that specific loci polymorphism of the TNFRSF1B, FCGR3A, IL1R, IL1B, and FAS genes could be a predictor of the primary non-response to anti-TNF therapy in CD patients. In this work, we propose to explain this hypothesis by functional analysis in colon biopsies and in a cell culture model. Using the RT-qPCR analysis, we estimated the FCGR3A, IL1R, TNFRSF1B, IL1B, FAS, and ADAM17 genes mRNA level in colon biopsies material from inflamed and non-inflamed tissue from 21 CD patients (14 responders and 7 non-responders to anti-TNF therapy) and 6 controls, as well as in vitro in a peripheral blood mononuclear cells (PBMCs) from 14 CD patients (seven responders and seven non-responders to anti-TNF therapy) and eight controls cultured for 72 h with 10 μg/ml of anti-TNF antibody. Our findings demonstrated a significant down-regulation of TNFRSF1B gene expression in non-responders both in inflamed and in non-inflamed colon tissue, while the expression of the FCGR3A and IL1B genes was significantly up-regulated in non-responders in the inflamed colon region. In vitro research results indicate that the anti-TNF drug induced a significant decrease in TNFRSF1B, FCGR3A, and FAS gene expression in non-responders. These results show that altered TNFRSF1B, FCGR3A, and IL1B genes expression can be a predictor of the primary non-response to anti-TNF therapy in CD patients.

Genistein attenuated gastric inflammation and apoptosis in Helicobacter pylori-induced gastropathy in rats

BackgroundHelicobacter pylori (H. pylori) infection is a major cause of chronic gastritis, peptic ulcer diseases and cancer. Genistein (4′,5,7-trihydroxyisoflavone), a tyrosine-specific-protein kinase inhibitor, has been shown to exert an anti-inflammatory property. The aim of this study was to examine the treatment effects of genistein and its mechanisms in rats with H. pylori infection.MethodsEighteen male Sprague-Dawley rats were divided into three groups (6 rats per group): (1) control group (Con); (2) H. pylori infected group (HP): the rats were inoculated with H. pylori (108− 1010 CFU/mL; 1 mL/rat.) for 3 consecutive days; and (3) HP + genistein group (HP + Gen): the rats were inoculated with H. pylori as above. Then, they were gavaged with genistein (16 mg/kg BW) for 14 days. Gastric tissue was used for the determination of nuclear factor (NF)-κB expression by immunohistochemistry (IHC), degree of apoptosis by the terminal deoxynucleotidyl transferasemediated dUTP nick-end labeling (TUNEL) reaction, and histopathology. Serum samples were used to measure the levels of tumor necrosis factor-alpha (TNF-α) and cytokine-induced neutrophil chemoattractant-1 (CINC-1).ResultsRats in the HP group had significantly higher levels of pro-inflammatory mediators, NF-κB expression and apoptotic cells when compared with the Con group, and these markers significantly decreased in HP + Gen group when compared with the HP group. The histopathology of HP group showed moderate gastric inflammation and many HP colonization. Gastric pathology in HP + Gen group demonstrated the attenuation of inflammatory cell infiltration and H. pylori colonization.ConclusionGenistein exerted its gastroprotective effects through the reduction of pro-inflammatory mediators, nuclear receptor NF-κB expression and gastric mucosal apoptosis in rats with H. pylori-induced gastropathy.

Clopidogrel-Induced Gastric Injury in Rats is Attenuated by Stable Gastric Pentadecapeptide BPC 157.

AimAlthough Clopidogrel is safe in healthy volunteers, it can induce recurrence of gastric ulcers in high-risk patients. Here, we investigated the protective effect of the natural product, stable gastric pentadecapeptide 157 (BPC 157) on Clopidogrel-induced gastric injury.MethodsWe used acetic acid to induce gastric ulcer in Sprague Dawley rats. Clopidogrel alone or in combination with BPC 157 or L-NAME (nitric oxide system blockade) were administered after healing of acetic acid-induced ulcer. One percent methylcellulose solution was used as control. Ulcer recurrence rate and the ulcer index were compared between these groups. Gastric mucosal apoptosis rate, microscopic inflammation activity and angiogenesis markers vascular endothelial growth factor A (VEGF-A) and CD34 were examined by TUNEL, histological evaluations (HE) and immunohistochemistry (IHC). Pathways involved, expressions of endoplasmic reticulum (ER) stress apoptosis marker CHOP, angiogenic markers VEGF-A and its receptor VEGFR1, and endothelial NO synthase (eNOS) were all analyzed by Western blot.ResultsThis study indicated that Clopidogrel significantly induced the gastric ulcers recurrence, severe inflammation and ER stress related apoptosis of the gastric mucosa, suppressed the synthesis of angiogenic markers and eNOS. Furthermore, Clopidrogel intervention resulted in the activation of protein kinase B (AKT) and p38 mitogen-activated protein kinase (p38/MAPK). BPC 157 attenuated the gastric mucosal damage caused by Clopidogrel and reversed these molecular effects. However, NO blockade L-NAME weakened the protective effect and thus the molecular effects of BPC 157 on gastric mucosa.ConclusionIn conclusion, these results suggest that BPC 157 inhibited Clopidogrel-induced gastric mucosa injury partially by inhibition of gastric mucosa cell ER stress-mediated apoptosis and inflammation, and promoting gastric mucosa angiogenesis via VEGF-A/VEGFR1 mediated-AKT/p38/MAPK signaling pathways.

Microarray Profiling and Functional Identification of LncRNA in Mice Intestinal Mucosa Following Intestinal Ischemia/Reperfusion

BackgroundIntestinal ischemia-reperfusion (I/R) injury is a common clinical event with high mortality, but its mechanism is elusive. Although long noncoding RNAs (lncRNAs) have recently emerged as critical molecules in I/R damage in other organs, the changes in their expression and potential roles in intestinal I/R remain unclear. MethodsThe expression profiles of both lncRNAs and mRNAs in mouse intestinal mucosa after intestinal I/R were explored by a microarray approach, and their biological functions were elucidated by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Then, some lncRNAs were further verified by qRT-PCR. Based on the coding-noncoding gene coexpression (CNC) network analyses, the role of lncRNA AK089510 in intestinal I/R-induced intestinal mucosa apoptosis was investigated by knockdown assay in vitro. ResultsA total of 3602 aberrantly expressed lncRNAs (1503 upregulated and 2099 downregulated) and 3158 mRNAs (1528 upregulated and 1630 downregulated) were identified. The dysregulated transcripts were enriched in the lipid metabolic process, apoptotic process, reactive oxygen species metabolic process, MAPK, TNF, ErbB, mTOR, and FoxO signaling pathways, and so on. The overexpression of lncRNA AK089510 was validated by qRT-PCR, and the CNC analysis revealed its target mRNAs. AK089510-siRNA reduced Casp6 and Casp7 expression and suppressed intestinal epithelial cell apoptosis after oxygen-glucose deprivation treatment. ConclusionsOur study revealed the lncRNA and mRNA expression patterns in mouse intestinal mucosa after intestinal I/R and predicted their potential functions and pathways. We identified AK089510 as a novel lncRNA involved in the apoptosis of intestinal mucosa, advancing our understanding of the molecular mechanisms of intestinal I/R injury.

Показатели пролиферации и апоптоза эпителиальных клеток слизистой оболочки желудка у коренных жителей Республики Тыва с Helicobacter pylori-позитивной язвенной болезнью двенадцатиперстной кишки

Показатели пролиферации и апоптоза эпителиальных клеток слизистой оболочки желудка у коренных жителей Республики Тыва с Helicobacter pylori-позитивной язвенной болезнью двенадцатиперстной кишки

The Effect of Tissue Tension in Radiation-Induced Rectal Toxicity: Apoptosis and Fibrosis

Gastrointestinal (GI) tract is vulnerable to ionizing radiation due to the nature of high-turnover-rate. For prostate cancer radiotherapy, the dosimetric advantage of endorectal ballooning has been suggested by the concept of high dose volume reduction. Furthermore, the possibility of toxicity reduction by biological effect has also been raised, whose mechanism is still unknown. We hypothesized the relationship between the GI toxicity and the macroscopic tension status of the tissue in terms of mucosal apoptosis and fibrotic change. Eight-week-old male Sprague Dawley rats were irradiated by high-energy X-ray. The radiation dose was categorized into low (15 Gy) and high (25 Gy) dose group with 5 daily fractionation. In all cases, a ballooning tube catheter was inserted into the rectum and the tissue tension levels were differentiated by injecting 1.3, 0.7, and 0.0 (non-ballooning) mL normal saline. Radiation volume was localized around the rectum via CT simulation to exclude systemic effects. Rectum tissue was harvested at the 3rd day (early phase, Ep) and the 28th day (late phase, Lp) after the end of irradiation. Mucosal fibrosis was quantitatively evaluated by the ratio of area occupied by collagen deposition on Picrosirius red-stained image. Apoptosis in rectal mucosa was estimated by cleaved caspase-3 positive cells. The mRNA expressions of IL-6, HIF-1α, VEGF-A, and NF-κB were analyzed as related markers. Mucosal collagen deposition tend to be greater in the non-ballooning group, and this tendency was more pronounced at Ep (p=0.010 versus 1.3 mL injection and p=0.020 versus 0.7 mL injection in 25 Gy radiation groups at Ep). Cleaved caspase-3 positivity tended to be dominant in the non-ballooning group as a whole, and statistical significance was relatively prominent for 25 Gy radiation at Lp (p<0.001 versus 1.3 mL injection and p=0.021 versus 0.7 mL injection). Despite relatively low statistical significance, IL-6 had a tendency to show dose-dependent response and time-dependent recovery except in the non-ballooning group. HIF-1α and VEGF-A showed similar profiles each other in terms of radiation dose and time phase. That is, the relative expression by low dose tended to be high in the non-injection group (p = 0.070 at Lp), whereas, in the injection group of 1.3 and 0.7 mL, this tendency disappeared at Lp. The effect of tissue tension was observed in mucosal fibrotic change and apoptosis with some mRNA expression. Apoptosis can be an index reflecting the degree of dose response relatively consistently. Despite no definite profile difference, tissue tension may act as a possible variable in the dose-dependent and time-related radiotoxicity of the rectum, suggesting the necessity of mechanical intervention-based approach in GI radiotoxicity assessment with more detailed approaches in future studies.

Prodigiosins from a marine sponge-associated actinomycete attenuate HCl/ethanol-induced gastric lesion via antioxidant and anti-inflammatory mechanisms.

Gastric ulcer is sores that form in the stomach mucosal layer because of erosion caused by high acid secretion and excessive use of non-steroidal anti-inflammatory drugs. Prodigiosins (PdGs) are red-pigmented secondary metabolites produced by bacteria, including actinomycetes. Butylcycloheptylprodigiosin (1) and undecylprodigiosin (2) were identified and isolated from a crude extract of the actinomycete RA2 isolated from the Red Sea Sponge Spheciospongia mastoidea. Chemical structure of 1 and 2 was determined by NMR and mass spectroscopy. Although their antioxidant and anti-inflammatory properties are known, their effect on gastric lesion is unknown. Therefore, this study aimed to investigate gastroprotective effects of PdGs against HCl/ethanol-induced gastric lesion in rats. Oral pretreatment with PdGs (100, 200, and 300 mg/kg) attenuated severity of HCl/ethanol-induced gastric mucosal injury, as evidenced by decreases in gastric lesion index scores, ulceration area, histopathologic abnormality, and neutrophil infiltration. These effects were comparable to those of omeprazole, a standard anti-gastric ulcer agent. HCl/ethanol-induced gastric erosions was associated with tremendous increases in lipid peroxidation, nitric oxide, and pro-inflammatory cytokines and mediators (myeloperoxidase, interleukin-1β, tumor necrosis factor-α, and cyclooxygenase-2), and with significant decreases in enzymatic and non-enzymatic antioxidant activities. However, PdGs ameliorated gastric inflammation and oxidative stress by downregulating nuclear factor kappa B and inducible nitric oxide synthase expression and upregulating heme oxygenase-1 expression. PdGs prevented gastric mucosal apoptosis by downregulating Bax and caspase-3 expression and upregulating Bcl-2 expression, thereby increasing prostaglandin E2 production. Our results suggested that PdGs exerted gastroprotective effects by decreasing the levels of inflammatory mediators, apoptotic markers, and antioxidants.

IL-6-Driven FasL Promotes Nf-κBp65/PUMA-Mediated Apoptosis in Portal Hypertensive Gastropathy

Background: Mucosal epithelial apoptosis with non-specific inflammation is an essential pathological characteristic in portal hypertensive gastropathy (PHG). However, whether a coordinated crosstalk between myeloid cells and epithelial cells involved in PHG remains unclear. Methods: Gastric injury and mucosal apoptosis were examined in patients with PHG and the PHG model of p65ΔM/ΔM (myeloid cells specific NF-κBp65 deletion) and p65f/f (floxed p65) mice, PUMA-WT (PUMA wild-type) and PUMA-KO (PUMA knockout) mice. The interaction of IL-6, Fas, FasL, NF-κBp65 and PUMA expression was investigated, and the mechanisms underlying IL-6-regulated gastric epithelial apoptosis were analysed. Findings: IL-6, which is induced in the mucosa of PHG patients and mice, promotes FasL production via enhancing NF-κBp65 activation in myeloid cells, while blockage of IL-6 signaling by Tocilizumab or deletion of NF-κBp65 in myeloid cells attenuates the inflammatory response and Fas/FasL-mediated epithelial apoptosis in PHG. IL-6-driven FasL from myeloid cells combines with epithelial Fas receptor to encourage NF-κBp65/PUMA-mediated epithelial apoptosis in PHG, and inhibition of NF-κBp65 or knockout of PUMA dramatically alleviates Fas/FasL network-mediated epithelial apoptosis in PHG. Interpretation: These results indicate that IL-6 drives FasL generation via NF-κBp65 in myeloid cells to promote Fas/NF-κBp65/PUMA-mediated epithelial apoptosis in PHG. Funding: This work was supported by grants from the National Natural Science Foundation of China (U1501224, 81700536), the Natural Science Foundation Team Project of Guangdong Province (2018B03031200), the Science and Technology Developmental Special Foundation of Guangdong Province (2017B020226003), the Basic Research Programme of Young Teachers' Training Project of Sun Yat-sen University (17ykpy51), the Science and Technology Planning Projects of Guangzhou City (201604020118, 201604020002). Declaration of Interest: The authors declare that there are no conflicts of interest. Ethical Approval: The study protocol and the acquisition of the tissue samples were approved by the Institutional Review Board of The Third Affiliated Hospital of Sun Yat-Sen University.

Inhibition of the ubiquitination of HSF1 by FBXW7 protects the intestine against ischemia-reperfusion injury.

Epithelial apoptosis is an important factor in intestinal ischemia-reperfusion (I/R) injury. Heat shock factor 1 (HSF1) is a classical stress response factor that directly regulates the transcription of heat shock proteins (HSPs) under stress conditions. Although HSPs are involved in protecting the intestine against I/R, the mechanism whereby HSF1 is regulated in I/R is poorly understood. Here, we show that the ubiquitin ligase FBXW7 targets HSF1 for ubiquitination and degradation in intestinal I/R. In this study, we found that FBXW7 expression was upregulated at the transcriptional level in intestinal mucosae subjected to I/R. In Caco-2 and IEC-6 cells subjected to hypoxia/reoxygenation (H/R), a high FBXW7 level led to excessive HSF1 ubiquitination and degradation. FBXW7 knockdown attenuated HSF1 ubiquitination and downregulation and accelerated HSPB1 and HSP70 expression. In addition, FBXW7 deletion alleviated the apoptosis of intestinal epithelial cells, as evidenced by decreased activation of caspase-3 and caspase-9. The results suggest that FBXW7 suppression protects against intestinal I/R, at least partly through the HSF1/HSP pathway. These findings indicate that FBXW7 may be a potential therapeutic target for inhibiting intestinal mucosa apoptosis during intestinal I/R.

Effect of hesperetin on inflammatory and oxidative status in trinitrobenzene sulfonic acid-induced experimental colitis model

In our study, the effect of hesperetin on inflammatory and oxidative status in trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis model was investigated through different methods. Eighteen Wistar albino male rats were divided in to three groups: Group I (Control, n = 8; 1 ml physiological saline), Group II (Colitis, n = 8; 1 ml TNBS), Group III (Hesperetin, n = 8; 1 ml TNBS and 100 mg/kg hesperetin). Macroscopic and microscopic scores were calculated to determine the damage to the colon at the end of the experiment. Serum tumor necrosis factor-α (TNF-α) and tissue interleukin-6 (IL-6) levels were determined using the ELISA method. Myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) levels were investigated spectrophotometrically. The TUNEL method was used for the detection of apoptotic cells in the colon tissue. Inducible nitric oxide synthase (iNOS) and nuclear factor-kappa-B (NF-ĸβ) expression in the colon were determined immunohistochemically. Hesperetin administration has shown to significantly reduce levels of MPO, MDA, and proinflammatory agents (TNF-α, IL-6, and NF-ĸβ). It has also been proven to inhibit mucosal apoptosis. This study indicates that hesperetin is protective against TNBS-induced colitis model via antiinflammatory, antioxidant and antiapoptotic effects.

Imipenem and normal saline with cyclophosphamide have positive effects on the intestinal barrier in rats with sepsis.

Sepsis is a life-threatening organ dysfunction caused the dysregulation of host inflammatory response and immunosuppression to infection Early recognition and intervention are hence of paramount importance. In this respect the "sepsis bundle" was proposed in 2004 to be instituted in cases of suspected sepsis. We hypothesised that a combination treatment of the sepsis bundle with cyclophosphamide would improve the function of the intestinal mucosa and enhance survival in rats with induced sepsis. Sprague-Dawley rats were divided into 5 different groups: sham, cecal ligation and puncture (CLP), cyclophosphamide (CTX), imipenem+normal saline (NS) and imipenem+NS+CTX. Cecal ligation and puncture were used for inducing the polymicrobial sepsis. Western-blot was used to measure the occludin protein, and ELISA for examining the plasma level of cytokines IL-6, IL-10 and TNF-α. TUNEL assay for testing the intestinal mucosal apoptosis, and hematoxylin-eosin staining for observing the intestinal mucosal changes. The permeability of intestinal mucosa was determined by the plasma level of FD-70. The results showed that the combination treatment of the sepsis bundle with cyclophosphamide attenuated cytokine levels, inhibited epithelial cell apoptosis and improved the function of the intestinal barrier. The survival rate of the group treated with the combined therapy was significantly higher than that of the other groups. The combination treatment of sepsis bundle with cyclophosphamide improves the function of the intestinal barrier and enhances survival in septic rats.

Ischemic Postconditioning Protects Against Intestinal Ischemia/Reperfusion Injury via the HIF-1\u03b1/miR-21 Axis

Intestinal ischemia/reperfusion (I/R) can lead to tissue damage associated with inflammation and mucosal apoptosis. Ischemic postconditioning (IPostC), a series of repeated, brief, intermittent periods of ischemia and reperfusion, has beneficial effects against I/R-induced injury in the heart and intestine, although the underlying mechanisms for these effects remain unclear. We evaluated the involvement of microRNA-21 (miR-21) in the protective effects of IPostC in a rat model of I/R induced by superior mesenteric artery occlusion and reopening. IPostC decreased I/R injury and suppressed apoptosis in the intestinal tissues concomitant with the induction of hypoxia inducible factor 1 alpha (HIF-1α) and the upregulation of miR-21. In vitro experiments in the intestinal epithelial cell line IEC-6 showed that hypoxia induced miR-21 and this effect was abolished by silencing HIF1-α, confirming the induction of miR-21 by HIF1-α, HIF1-α or miR-21 inhibition exacerbated I/R induced apoptosis, and programmed cell death 4 (PDCD4) and Fas-L was involved in miR-21 mediated anti-apoptotic effects on intestinal epithelial cells. Knockdown of miR-21 or inhibition of HIF1-α abolished the IPostC-mediated attenuation of intestinal injury and apoptosis and the downregulation of PDCD4 and Fas-L. A potential mechanism underlying the protective effect of IPostC may therefore involve the induction of miR-21 by HIF1-α and the attenuation of apoptosis via the downregulation of PDCD4 and Fas-L.

Short Chain Fatty Acid Acetate Protects against Ethanol-Induced Acute Gastric Mucosal Lesion in Mice.

Short chain fatty acids acetate and propionate have been demonstrated protective function in the intestinal mucosa. However, their impact on gastric mucosa has not yet been elucidated. The current study aimed to investigate the potential protective effects of acetate and propionate against ethanol-induced gastric mucosal lesion and the underlying mechanism in mice. ICR mice were orally treated with acetate and propionate, respectively, 30 min prior to the establishment of gastric mucosal injury model by challenge with absolute ethanol. The gastric samples were collected for the detection of oxidative, inflammatory and apoptotic related parameters. Acetate, but not propionate, attenuated the severity of gastric mucosal damage as evidenced by the gross changes of gastric mucosa, pathological aberrations. Acetate alleviated oxidative stress as shown by the increase in glutathione (GSH) content and superoxide dismutase (SOD) activities, and the decrease of malondialdehyde (MDA) level. The elevated concentrations of interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6, and the activation of nuclear factor-kappaB (NF-κB) p65 by ethanol stimulation was also reduced by acetate. Moreover, the anti-inflammatory factors, IL-4, LXA4 and IL-10, were up-regulated in acetate treated group. With respect to gastric mucosal apoptosis, acetate suppressed caspase-3 activity and BAX expression in favor of cell survival. These favorable actions were maybe associated with up-regulation of the gastric MUC5AC, the key defense factor of gastric mucosal system. These findings accentuate the gastroprotective actions of acetate in ethanol-induced gastric injury which were mediated via concerted multi-prolonged actions, including suppression of gastric oxidation, inflammation and apoptosis and promotion of MUC5AC expression.

Infliximab therapy reverses the increase of allograft inflammatory factor-1 in serum and colonic mucosa of rats with inflammatory bowel disease

Objective: Our purpose was to study the molecular basis of infliximab (IFX) effect on colon mucosa in a colitis model and to identify new biomarkers of mucosal healing.Methods: Healthy rats and rats which were subjected to experimental colitis induced by dextran sulfate sodium, with or without IFX treatment (in the short- and long-term), were studied along with forty-seven IBD patients. Colon mucosal integrity by periodic acid Schiff (PAS) staining, intestinal damage by immunohistochemistry (proliferating cell nuclear antigen, β-catenin, E-cadherin, phosphotyrosine, p-p38, allograft inflammatory factor-1 (AIF-1) and colonic mucosal apoptosis by TUNEL staining were evaluated in rats while serum and colon AIF-1 levels were determined in IBD patients.Results: In rats with colitis, IFX reestablished the epithelial barrier integrity, recovered mucus production and decreased colon inflammation, as verified by reduced serum and colon AIF-1 levels; colon and serum AIF-1 levels were also lower in inactive IBD patients compare to active ones. P38 activation after IFX treatment tended to induce differentiation/proliferation of epithelial cells along the colonic crypt-villous axis.Conclusions: These findings support AIF-1 as a new biomarker of mucosal healing in experimental colitis and suggest that p38 activation is involved in the mucosal healing intracellular mechanism induced by IFX treatment.

Perturbation of neddylation-dependent NF-κB responses in the intestinal epithelium drives apoptosis and inhibits resolution of mucosal inflammation.

Recent work has revealed a central role for neddylation (the conjugation of a Nedd8-moiety to Cullin proteins) in the fine tuning of the NF-κB response (via Cullin-1). In the present study, we investigated the contribution of Cullin-1 neddylation and NF-κB signaling to mucosal inflammatory responses in vitro and in vivo. Initial in vitro studies using cultured intestinal epithelial cells revealed that the neddylation inhibitor MLN4924 prominently induces the deneddylation of Cullin-1. Parallel western blot, luciferase reporter and gene target assays identified MLN4924 as a potent inhibitor of intestinal epithelial NF-κB. Subsequent studies revealed that MLN4924 potently induces epithelial apoptosis but only in the presence of additional inflammatory stimuli. In vivo administration of MLN4924 (3 mg/kg/d) in a TNBS-induce colitis model significantly accentuated disease severity. Indeed, MLN4924 resulted in worsened clinical scores and increased mortality early in the inflammatory response. Histologic analysis of the colon revealed that neddylation inhibition results in increased tissue damage and significantly increased mucosal apoptosis as determined by TUNEL and cleaved caspase-3 staining, particularly prominent within the epithelium. Extensions of these studies revealed that ongoing inflammation is associated with significant loss of deneddylase-1 (SENP8) expresssion. These studies reveal that intact Cullin-1 neddylation is central to resolution of acute inflammation.

Extracorporeal circulation increases proliferation in the intestinal mucosa in a large animal model

Extracorporeal circulation induces ischemia/reperfusion injury in the small intestinal wall. One reason for this damage is a perfusion shift from the muscular toward the mucosal layer. This study investigated the effect of this perfusion shift on the small-intestinal apoptosis and proliferation. Twenty-eight pigs were randomly assigned to the following cohorts and underwent a thoracolaparotomy and a 1hour main procedure: cohort I: control; cohort II: thoracic aortic cross-clamping (TAC) without perfusion; cohort III: TAC and distal aortic perfusion (DAP); cohort IV: TAC, DAP, and selective visceral perfusion. The main procedure was followed by 2hours of reperfusion in all cohorts. Tissue samples were taken during the experiment, stained, and analyzed for apoptosis and proliferation (caspase-3, annexin-V, terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling, and proliferating cell nuclear antigen). Six animals died unexpectedly during the experiment and were excluded from the analysis. Extensive tissue damage and necrosis was only found in cohort II after the main procedure. In the mucosa, the proliferation was increased in cohort III at the end of the experiment (P= .0157 cohort I vs II). In contrast, the annexin-V/proliferating cell nuclear antigen ratio was significantly higher in cohorts II and IV than in cohorts I and II at the end of the experiment (P= .0034). Furthermore, the caspase-3/annexin-V ratio was increased in all cohorts at the end of the experiment (P= .0015). Mucosal proliferation is the early repair mechanism of the limited small intestinal ischemia/reperfusion injury after DAP. Furthermore, the extensive surgical trauma shifted the mucosal apoptosis into an advanced state.