Molecular regulation mechanism of intestinal stem cells in mucosal injury and repair in ulcerative colitis

Ulcerative colitis(UC)is a chronic nonspecific inflammatory disease with complex causes.The main pathological changes were intestinal mucosal injury.Leucinerich repeat-containing G protein coupled receptor 5(LGR5)-labeled small intestine stem cells(ISCs)were located at the bottom of the small intestine recess and inlaid among Paneth cells.LGR5+small ISCs are active proliferative adult stem cells,and their self-renewal,proliferation and differentiation disorders are closely related to the occurrence of intestinal inflammatory diseases.The Notch signaling pathway and Wnt/β-catenin signaling pathway are important regulators of LGR5-positive ISCs and together maintain the function of LGR5-positive ISCs.More importantly,the surviving stem cells after intestinal mucosal injury accelerate division,restore the number of stem cells,multiply and differentiate into mature intestinal epithelial cells,and repair the damaged intestinal mucosa.Therefore,in-depth study of multiple pathways and transplantation of LGR5-positive ISCs may become a new target for the treatment of UC.

Ligustrazine alleviates gastric mucosal injury in a rat model of acute necrotizing pancreatitis

BACKGROUND: Acute necrotizing pancreatitis (ANP) leads to a systemic inflammatory response characterized by widespread leukocyte activation and, as a consequence, distant organ injury. The aim of this study was to explore the relationship between gastric microcirculatory impairment and inflammatory mediators released in rats and to evaluate the therapeutic effect of ligustrazine extracted from Rhizoma ligusticum wallichii on gastric mucosa injury in a rat model of ANP. METHODS: Ninety-six Sprague-Dawley rats were randomly divided into three groups: normal control (group Q; ANP without treatment (group P); and ANP treated with ligustrazine (group T). The ANP model was induced by injection of 50 g/L sodium taurocholate under the pancreatic membrane (4 ml/kg). Group C was given isovolumetric injection of 9 g/L physiological saline by the same route. Group T was injected with ligustrazine (10 ml/kg) via the portal vein. The radioactive biomicrosphere technique was used to measure the blood flow 2 and 12 hours after the induction of ANP. Samples of the pancreas and stomach were taken to assess pathological changes by a validated histology score; meanwhile, the levels of serum interleukin-1 beta (IL-1 beta) were determined. Gastric tissues were also used to measure the level of myeloperoxidase (MPO), which is expressed intracellularly in the azurophilic granules of neutrophils. RESULTS: Blood flow in group P was significantly lower than that in group C (P < 0.01). Pathological changes were significantly aggravated in group P. The gastric MPO activity in group P was significantly higher than that in group C (P < 0.01). The level of serum IL-1 beta in group P increased more significantly than that in group C (P < 0.01). Blood flow of the stomach in group T was significantly higher than that in group P after 2 hours (P < 0.01). The pathological changes were significantly alleviated in group T. The MPO activity of group T was significantly lower than that of group P (P < 0.01). Although serum IL-1 beta level of group T, was higher than of group C (P < 0.01), it was lower than that of group P (P < 0.01). There was a negative correlation between gastric blood flow and MPO activity (r=-0.983, P < 0.01), and between gastric blood flow and pathological score (r=-0.917, P < 0.05). CONCLUSIONS: Decreased gastric blood flow and increased inflammatory mediators can be seen early in ANP, and both are important factors for gastric and mucosal injury. Ligustrazine can ameliorate microcirculatory disorder and alleviate the damage to the pancreas and stomach.

Protective effect of clodronate-containing liposomes on intestinal mucosal injury in rats with severe acute pancreatitis

BACKGROUND: Severe acute pancreatitis (SAP) can result in intestinal mucosal injury. This study aimed to demonstrate the protective effect of clodronate-containing liposomes on intestinal mucosal injury in rats with SAP. METHODS: Liposomes containing clodronate or phosphate buffered saline (PBS) were prepared by the thin-film method SAP models were prepared by a uniform injection of sodium taurocholate (2 mL/kg body weight) into the subcapsular space of the pancreas. Sprague-Dawley rats were randomly divided into a control group (C group), a SAP plus PBS-containing liposomes group (P group) and a SAP plus clodronate-containing liposomes group (T group). At 2 and 6 hours after the establishment of SAP models, 2 mL blood samples were taken from the superior mesenteric vein to measure the contents of serum TNF-α and IL-12. Pathological changes in the intestine and pancreas were observed using hematoxylin and eosin staining, while apoptosis was detected using TUNEL staining. In addition, the macrophage markers cluster of differentiation 68 (CD68) in the intestinal tissue was assessed with immunohistochemistry. RESULTS: At the two time points, the levels of TNF-α and IL-12 in the P group were higher than those in the C group (P<0.05) Compared with the P group, the levels of TNF-α and IL-12 decreased in the T group (P<0.05). The pathological scores of the intestinal mucosa and pancreas in the T group were lower than those of the P group. In the T group, large numbers of TUNEL-positive cells were observed, but none or few in the C and P groups. The number of CD68-positive macrophages decreased in the T group.CONCLUSIONS: Clodronate-containing liposomes have prote- ctive effects against intestinal mucosal injury in rats with SAP. The blockade of macrophages may provide a novel therapeutic strategy in SAP.

Total triterpenes from fruits of Chaenomeles speciosa(Sweet) Nakai protect against indomethacin-induced gastric mucosal injury: involvement of TFF1-mediated EGF/EGFR and apoptotic pathways

OBJECTIVE Gastric ulcers affect people of all ages and half of the world's population,which is being considered as the new"plague of the 21st century".As is well known,gastric mucosa is known as the first guard to protect the stomach from ulcer injury,while the aetiology of gastric ulcer is relative to imbalances between gastric mucosal protective and aggressive factors.Therefore,reducing or eliminating the aggressive factors,returning to the balance of between mucosal protective and aggressive factors,and then restoring the normal functional of gastric mucosal barrier could be crucial for treating the gastric ulcer.The fruits of Chaenomeles speciosa(TCS),also known as"mugua",might be processed into edible and health care derived products,and used as a commonly used traditional medicine in China for thousands of years.In China folk,there is a saying that"apricot one benefit,pear two benefits,mgua hundred benefits",so it has a"hundred-benefit"fruit reputation.Tujia nationality inhabitants in Southwestern China should have rheumatic diseases and peptic ulcers for living in the damp environments and bingeing on spicy and pungent foods.For the exis⁃tence of the fruit derived products of Chaenomeles speciosa as their complementary foods or snacks,the habit makes them rarely suffer from the two kinds of diseases.Enlightened by these,we had investigated the structure-activity rela⁃tionships,screened out CSTT with gastroprotective activity.Our previous studies demonstrated that TCS owned effec⁃tively therapeutic effects on gastric ulcer patients and animals,and further confirmed that TFF1 and apoptotic pathway were closely interrelated with its exerting gastroprotection.However,its underlying molecular mechanisms involved have not been fully elucidated.The current study was to further investigate its protective effect on indomethacin(IND)-damaged RGM-1 cells and rats and its underlying mechanisms through modulating TFF1-mediated EGF/EGFR and apoptotic pathways.METHODS The gastroprotection of TCS was evaluated with IND-induced gastric lesions model in RGM-1 cells and rats.In vitro,the proliferation,migration,mitochondrial viability and apoptosis were assessed,In vivo,ulcer index,ulcer inhibition rate,gastric juice acidity,gastric wall mucus(GWM),histopathology of gastric mucosa were detected.The gastroprotective effects of TCS through the TFF1-mediated EGFR/EGFR and apoptotic pathways were presented and measured by qRT-PCR and Western blotting assays.RESULTS TCS had gastroprotective function,which was related to the amelioration in promoting IND-damaged RGM-1 cell proliferation and migration,hoisting gastric juice acidity and GWM,improving ulcer index and ulcer inhibition rate,attenuating the hemorrhage,edema,epithelial cell loss and inflammatory cell infiltration of gastric mucosa,upregulating proliferation cell nuclear antigen,Bcl-2,Bcl-xl mRNA and TFF1,EGF,p-EGFR,p-Src,pro-caspase-3,pro-caspase-9 protein expressions,mitochondrial viability,mitochondrial cytochrome C concentration and p-EGFR/EGFR,p-Src/Src,Bcl-2/Bax,Bcl-xl/Bad ratioes,downregulating Bax,Bad,Apaf-1 mRNA and cleaved-caspase-3,cleaved-caspase-9,cleaved-PARP-1 protein expressions,cytosol cytochrome C concentration.CONCLUSION TCS′s gastroprotective effect was closely connected with boosting TFF1 expression,acti⁃vating TFF1-mediated EGF/EGFR pathway,thus restraining mitochondrial-dependent apoptosis,which provided new insights into interpreting its underlying mechanism and promised to act as a candidate drug to treat gastric mucosal injury.

Protective role of fruits of Rosa odorata var. gigantea against WIRSinduced gastric mucosal injury in rats by modulating pathway related to inflammation, oxidative stress and apoptosis

Objective: Rosa odorata var. gigantea is a popular medicinal plant. Some studies have demonstrated that ethanolic extract of the fruits of R. odorata var. gigantea(FOE) has gastroprotective properties. The aim of this study was to investigate the gastroprotective activity of FOE on water immersion restrained stress(WIRS)-induced gastric mucosal injury in a rat model and elucidate the possible molecular mechanisms involved.Methods: A rat stress ulcer model was established in this study using WIRS. After rats were treated with FOE orally for 7 d, the effect of FOE treatment was analyzed by hematoxylin and eosin(H&E) staining, and the changes of inflammatory factors, oxidative stress factors, and gastric-specific regulatory factors and pepsin in the blood and gastric tissues of rats were examined by ELISA assay. Molecular mechanism of FOE was investigated by immunohistochemical assay and Western blot.Results: Compared with the WIRS group, FOE could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. FOE significantly preserved the antioxidants glutathione peroxidase(GSH-PX), superoxide dismutase(SOD) and catalase(CAT) contents;anti-inflammatory cytokines interleukin-10(IL-10) and prostaglandin E2(PGE2) levels as well as regulatory factors tumor necrosis factor-a(TGF-a) and somatostatin(SS) contents, while decreasing malondialdehyde(MDA), nitric oxide synthase(i NOS), tumor necrosis factor(TNF-a), interleukin-1β(IL-1β), interleukin-6(IL-6), gastrin(GAS)and endothelin(ET) levels. Moreover, FOE distinctly upregulated the expression of Nrf2, HO-1, Bcl2 and proliferating cell nuclear antigen(PCNA). In addition, FOE activated the expression of p-EGFR and downregulated the expression of NF-ΚB, Bax, Cleaved-caspase-3, Cyto-C and Cleaved-PARP1, thus promoting gastric mucosal cell survival.Conclusion: The current work demonstrated that FOE exerted a gastroprotective activity against gastric mucosal injury induced by WIRS. The underlying mechanism might be associated with the improvement of anti-inflammatory, anti-oxidation and anti-apoptosis systems.

Prospective randomized study correlating intra-operative urethral mucosal injury with early period after transurethral resection of the prostate stricture urethra: A novel concept

Objective:To investigate the incidence of urethral stricture during the early period after transurethral resection of the prostate(TURP)and correlate its incidence with intra-operative urethral mucosal injury during TURP.Also to compare the other established risk factors affecting the development of urethral stricture among patients undergoing monopolar or bipolar TURP over a period of 6 months follow-up as the prospective randomized study.Methods:One hundred and fifty men older than 50 years with lower-urinary tract symptoms associated with benign prostatic hyperplasia were randomized to undergo either standard monopolar TURP with glycine as the irrigation fluid or bipolar TURP with normal saline as irrigant.The prostate size,operative time,intra-operative mucosal rupture,catheter time,catheter traction duration,uroflowmetry,and post-operative stricture rate were compared.Results:A total of 150 patients underwent TURP,including 74 patients undergoing monopolar TURP(one patient was excluded as his post-operative histopathological examination report was of adenocarcinoma prostate)and 75 patients undergoing bipolar-TURP,all of which were performed using a 26 Fr sheath resectoscope.The mean International Prostate Symptom Score and maximum urinary flow rate score at post-operative 3 months and 6 months were comparable between the groups.Out of 149 patients,nine patients(6.0%)developed urethral stricture.The severity of the injury(urethral mucosal injury)correlated with the likelihood of developing a subsequent complication(stricture urethra).Patients with stricture had significantly larger prostate volume than patients without stricture(65.0 mL vs.50.0 mL;p=0.030).Patients with stricture had longer operative time than patients without stricture(55.0 min vs.40.0 min;p=0.002).In both procedures,formation of post-operative stricture urethra was independently associated with intra-operative mucosal injury.Conclusion:Intra-operative recognition of urethral mucosal injury helps in prediction of stricture urethra formation in early post-operative period.

Study of Clinical and Genetic Risk Factors for Aspirin-inducec Gastric Mucosal Injury

Background： Current knowledge about clinical and genetic risk factors for aspirin-induced gastric mucosal injury is not sufficient to prevent these gastric mucosal lesions. Methods： We recruited aspirin takers as the exposed group and healthy volunteers as the control group. The exposed group was categorized into two subgroups such as subgroup A as gastric mucosal injury diagnosed by gastroscopy, including erosion, ulcer or bleeding of the esophagus, stomach, or duodenum; subgroup B as no injury of the gastric mucosa was detected by gastroscopy. Clinical information was collected, and 53 single nucleotide polymorphisms were evaluated. Results： Among 385 participants, 234 were in the aspirin-exposed group. According to gastroscopy, 82 belonged to subgroup A, 91 belonged to subgroup B, and gastroscopic results of 61 participants were not available. Using the Chi-square test and logistic regression, we found that peptic ulcer history （odds ratio [OR] = 5.924, 95% confidence intervals [C/]： 2.115-16.592）, dual anti-platelet medication （OR = 3.443, 95% CI： 1.154-10.271 ）, current Helicobacterpylori infection （OR = 2.242, 95% CI： 1.032-4.870）, male gender （OR = 2.211, 95% CI： 1.027-4.760）, GG genotype ofrs2243086 （OR = 4.516, 95% CI： I. 180-17.278）, and AA genotype ofrs 1330344 （OR = 2.178, 95% CI： 1.016-4.669） were more frequent in subgroup A than subgroup B. In aspirin users who suffered from upper gastrointestinal bleeding, the frequency of the TT genotype ofrs2238631 and TT genotype ofrs2243100 was higher than in those without upper gastrointestinal bleeding. Conclusions： Peptic ulcer history, dual anti-platelet medication, tt. pylori current infection, and male gender were possible clinical risk factors for aspirin-induced gastric mucosal injury. GG genotype of rs2243086 and AA genotype of rs 1330344 were possible genetic risk factors. TT genotype ofrs2238631 and TT genotype ofrs2243100 may be risk factors for upper gastrointestinal bleeding in aspirin users.

Effect of Weikang Capsule(胃康胶囊)on Aspirin-Related Gastric and Small Intestinal Mucosal Injury

Objective To investigate the effects of Weikang Capsule(胃康胶囊,WKC)on aspirin-related gastric and small intestinal mucosal injury by magnetically controlled capsule endoscopy(MCCE).Methods Patients taking enteric-coated aspirin aged 40-75 years were enrolled in Beijing Anzhen Hospital,Capital Medical University from January 2019 to December 2019.The patients continued taking aspirin Tablet(100 mg per day)and underwent MCCE before and after 1-month combined treatment with WKC(0.9 g per time orally,3 times per day).The gastrointestinal symptom score,gastric Lanza score,the duodenal,jejunal and ileal mucosal injury scores were used to evaluate the gastrointestinal injury before and after treatment.Adverse events including nausea,vomiting,abdominal pain,abdominal distension,abdominal discomfort,dizziness,or headache during MCCE and combined treatment were observed and recorded.Results Twenty-two patients(male/female,13/9)taking enteric-coated aspirin aged 59.5±11.3 years with a duration of aspirin use of 28.0(1.0,48.0)months were recruited.Compared with pre-treatment,the gastrointestinal symptom rating scale scores,gastric Lanza scores,and duodenal mucosal injury scores were significantly reduced after 1-month WKC treatment(P<0.05),and jejunal and ileal mucosal injury scores showed no obvious change.No adverse events occurred during the trial.Conclusions WKC can alleviate gastrointestinal symptoms,as well as gastric and duodenal mucosal injuries,in patients taking enteric-coated aspirin;it does not aggravate jejunal or ileal mucosal injury,which may be an effective alternative for these patients(Clinical trial registry No.ChiCTR1900025451).