Betaine addition to the diet alleviates intestinal injury in growing rabbits during the summer heat through the AAT/mTOR pathway

Background The aim of this experiment was to investigate the effect of different levels of betaine(Bet)inclusion in the diet on the intestinal health of growing rabbits under summer heat.A total of 100 weaned Qixing meat rabbits aged 35 d with body weight of 748.61±38.59 g were randomly divided into 5 treatment groups:control group(basal diet)and Bet groups(basal diet+0.75,1.0,1.5 or 2.0 g/kg Bet).The average daily temperature in the rabbitry during the experiment was 30.48°C and the relative humidity was 69.44%.Results Dietary addition of Bet had no significant effect on growth performance and health status of growing rabbits(P>0.05),but it increased ileal secretory immunoglobulin A content compared to the control under summer heat(P<0.05).Addition of 0.75 g/kg Bet up-regulated jejunal IL-4,down-regulated ileal TNF-αexpression(P<0.05).The addition of 1.0 g/kg Bet increased the villi height(VH)in the jejunum(P<0.05).Serum glucose levels were reduced,and the expression of SLC6A20 was up-regulated in jejunum and ileum of rabbits fed with 1.5 g/kg Bet(P<0.05).When added at 2.0 g/kg,Bet reduced serum HSP70 content,increased jejunal VH,and up-regulated duodenal SLC7A6,SLC38A2,mTOR and 4EBP-2 expression(P<0.05).Correlation analysis revealed that intestinal mTOR expression was significantly and positively correlated with SLC7A6,SLC38A2,SLC36A1 and IL-4 expression(P<0.05).Conclusions Dietary addition of Bet can up-regulate the expression of anti-inflammatory factors through the AAT/mTOR pathway,improve the intestinal immune function,alleviate intestinal damage in growing rabbits caused by summer heat,and improve intestinal health.

Prevention and management of non-steroidal anti-inflammatory drugs-induced small intestinal injury

Non-steroidal anti-inflammatory drug （NSAID）-induced small bowel injury is a topic that deserves attention since the advent of capsule endoscopy and balloon enteroscopy. NSAID enteropathy is common and is mostly asymptomatic. However, massive bleeding, stricture, or perforation may occur. The pathogenesis of small intestine injury by NSAIDs is complex and different from that of the upper gastrointestinal tract. No drug has yet been developed that can completely prevent or treat NSAID enteropathy. Therefore, a long-term randomized study in chronic NSAID users is needed.

Over-starvation aggravates intestinal injury and promotes bacterial and endotoxin translocation under high-altitude hypoxic environment

AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.

Plasma non-transferrin-bound iron uptake by the small intestine leads to intestinal injury and intestinal flora dysbiosis in an iron overload mouse model and Caco-2 cells

Iron overload often occurs during blood transfusion and iron supplementation, resulting in the presence of non-transferrin-bound iron(NTBI) in host plasma and damage to multiple organs, but effects on the intestine have rarely been reported. In this study, an iron overload mouse model with plasma NTBI was established by intraperitoneal injection of iron dextran. We found that plasma NTBI damaged intestinal morphology, caused intestinal oxidative stress injury and reactive oxygen species(ROS) accumulation,and induced intestinal epithelial cell apoptosis. In addition, plasma NTBI increased the relative abundance of Ileibacterium and Desulfovibrio in the cecum, while the relative abundance of Faecalibaculum and Romboutsia was reduced. Ileibacterium may be a potential microbial biomarker of plasma NTBI. Based on the function prediction analysis, plasma NTBI led to the weakening of intestinal microbiota function, significantly reducing the function of the extracellular structure. Further investigation into the mechanism of injury showed that iron absorption in the small intestine significantly increased in the iron group. Caco-2 cell monolayers were used as a model of the intestinal epithelium to study the mechanism of iron transport. By adding ferric ammonium citrate(FAC, plasma NTBI in physiological form) to the basolateral side, the apparent permeability coefficient(Papp) values from the basolateral to the apical side were greater than 3×10^(-6)cm s^(-1). Intracellular ferritin level and apical iron concentration significantly increased, and SLC39A8(ZIP8) and SLC39A14(ZIP14) were highly expressed in the FAC group.Short hairpin RNA(sh RNA) was used to knock down ZIP8 and ZIP14 in Caco-2 cells. Transfection with ZIP14-specific sh RNA decreased intracellular ferritin level and inhibited iron uptake. These results revealed that plasma NTBI may cause intestinal injury and intestinal flora dysbiosis due to the uptake of plasma NTBI from the basolateral side into the small intestine, which is probably mediated by ZIP14.

Evaluating a novel protective agent against radiation-induced acute intestinal injury

Objective:To develop and synthesize a novel derivative of ethyl pyruvate,named TZC02,and investigate its radioprotective effects against ionizing radiation(IR)-induced intestinal injury in mice.Methods:Male C57BL/6J mice weighing(20±2)g in the survival experiment were randomly divided into five groups(n=10 in each):control group,IR group,IR+TZC02(50 mg/kg)group,IR+TZC02(100 mg/kg)group,and IR+TZC02(200 mg/kg)group.Mice's survival rates were monitored for 7 d.In other experiments,the male mice were randomly divided into three groups(n=5 per group):control group,IR group,and IR+TZC02(100 mg/kg)group.TZC02 was intragastrically administered 1 h before 12 Gy abdominalγ-ray irradiation(ABI)and 24 h,48 h after irradiation,respectively.Three days after IR exposure,small intestinal tissues were collected and the number of small intestinal crypts was determined using hematoxylin&eosin(H&E)staining.Immunohistochemical analysis was used to assess the regenerative capacity of the small intestine(SI)and radiation-induced damage,stemness markers or DNA repair surrogates,including Ki67,lysozyme,and villus.The expressions of histone H2AX phosphorylation(γH2AX)and caspase-3 were evaluated through immunofluorescence analyses.Additionally,in vitro cultured small intestinal organoids were employed to investigate the effects of TZC02 on SI regeneration after irradiation.Results:The administration of TZC02 significantly improved the 7 d-survival rate of mice exposed to 12 Gy ABI(P<0.05).Compared to the IR group,TZC02 treatment attenuated the decrease of SI Ki67-positive cells[(59.60±6.33)vs.(37.70±7.82),t=11.89,P<0.0001]and Paneth cells[(9.90±1.37)vs.(5.50±1.71),t=6.02,P<0.001]in five crypts,and reduced structural damage to the SI[villus height,(349.49±60.17)μm vs.(294.72±40.09)μm;t=3.39;P<0.05].TZC02 also significantly decreased the crypt apoptosis detected by caspase-3[(10.75±1.26)vs.(29.83±2.56),t=13.39,P<0.0001]and DNA damage detected by gH2AX[(10.40±1.14)vs.(29.60±2.70),t=10.13,P<0.0001].The organoid survival 7 d post-irradiation further confirmed the protective effects of TZC02(area of organoids,(0.119±0.081)mm^(2)vs.(0.080±0.037)mm^(2);t=2.30;P<0.05).Conclusions:This study demonstrate that TZC02 can offer effective protection against IR-induced intestinal injury,suggesting its potential as a promising protective compound for patients treated with radiotherapy.

Activating transcription factor 4 protects mice against sepsis-induced intestinal injury by regulating gut-resident macrophages differentiation

Background: Gut-resident macrophages (gMacs) supplemented by monocytes-to-gMacs differentiation play a critical role in maintaining intestinal homeostasis. Activating transcription factor 4 (ATF4) is involved in immune cell differentiation. We therefore set out to investigate the role of ATF4-regulated monocytes-to-gMacs differentiation in sepsis-induced intestinal injury.Methods: Sepsis was induced in C57BL/6 wild type (WT) mice andAtf4-knockdown (Atf4+/-) mice by cecal ligation and puncture or administration of lipopolysaccharide (LPS). Colon, peripheral blood mononuclear cells, sera, lung, liver, and mesenteric lymph nodes were collected for flow cytometry, hematoxylin and eosin staining, immunohistochemistry, quantitative reverse transcription polymerase chain reaction, and enzyme-linked immunosorbent assay, respectively.Results: CD64, CD11b, Ly6C, major histocompatibility complex-II (MHC-II), CX3CR1, Ly6G, and SSC were identified as optimal primary markers for detecting the process of monocytes-to-gMacs differentiation in the colon of WT mice. Monocytes-to-gMacs differentiation was impaired in the colon during sepsis and was associated with decreased expression of ATF4 in P1 (Ly6Chi monocytes), the precursor cells of gMacs.Atf4 knockdown exacerbated the impairment of monocytes-to-gMacs differentiation in response to LPS, resulting in a significant reduction of gMacs in the colon. Furthermore, compared with WT mice,Atf4+/- mice exhibited higher pathology scores, increased expression of inflammatory factor genes (TNF-α, IL-1β), suppressed expression of CD31 and vascular endothelial-cadherin in the colon, and increased translocation of intestinal bacteria to lymph nodes and lungs following exposure to LPS. However, the aggravation of sepsis-induced intestinal injury resulting fromAtf4 knockdown was not caused by the enhanced inflammatory effect of Ly6Chi monocytes and gMacs.Conclusion: ATF4, as a novel regulator of monocytes-to-gMacs differentiation, plays a critical role in protecting mice against sepsis-induced intestinal injury, suggesting that ATF4 might be a potential therapeutic target for sepsis treatment.

Preventive effect of tetramethylpyrazine on intestinal mucosal injury in rats with acute necrotizing pancreatitis

AIM： To evaluate the role of microcirculatory disorder （MCD） and the therapeutic effectiveness ;of tetramethylpyrazine （TMP） on intestinal mucosa injury in rats with acute necrotizing pancreatitis （ANP）.METHODS： A total of 192 Sprague-Dawley rats were randomly divided into three groups： normal control group （C group）, ANP group not treated with TMP （P group）, ANP group treated with TMP （T group）. An ANP model was induced by injection of 50 g/L sodium taurocholate under the pancreatic membrane （4 mL/kg）. C group received isovolumetric injection of 9 g/L physiological saline solution using the same method. T group received injection of TMP （10 mL/kg） via portal vein. Radioactive biomicrosphere technique was used to measure the blood flow at 0.5, 2, 6 and 12 h after the induction of ANP. Samples of pancreas, distal ileum were collected to observe pathological changes using a validated histology score. Intestinal tissues were also used for examination of myeloperoxidase （MPO） expressed intraceUularly in azurophilic granules of neutrophils.RESULTS： The blood flow was significantly lower in P group than in C group （P 〈 0.01）. The pathological changes were aggravated significantly in P group. The longer the time, the severer the pathological changes. The intestinal MPO activities were significantly higher in P group than in C group （P 〈 0.01）. The blood flow of intestine was significantly higher in T group than in P group after 2 h （P 〈 0.01）. The pathological changes were alleviated significantly in T group. MPO activities were significantly lower in T group than in P group （P 〈 0.01 or P 〈 0.05）. There was a negative correlation between intestinal blood flow and MPO activity （r = -0.981, P 〈 0.01） as well as between intestinal blood flow and pathologic scores （r = -0.922, P 〈 0.05）.CONCLUSION： MCD is an important factor for intestinal injury in ANP. TMP can ameliorate the condition of MCD and the damage to pancreas and intestine.

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.

Protective effect of Astragalus membranaceus on intestinal mucosa reperfusion injury after hemorrhagic shock in rats

AIM： To study the protective effect of Astragalus rnernbranaceus on intestinal mucosa reperfusion injury and its mechanism after hemorrhagic shock in rats. METHODS： A total of 32 SD rats were randomly divided into four groups （n = 8, each group）： normal group, model group, low dosage group （treated with 10 g/kg Astragalus membranaceus） and high dosage group （treated with 20 g/kg Astragalus membranaceus）. The model of hemorrhagic shock for 60 min and reperfusion for 90 min was established. Therapeutic solution （3 mL） was administrated before reperfusion. At the end of the study, the observed intestinal pathology was analyzed. The blood concentrations of lactic acid （LD）, nitric oxide （NO）, endothelin-1 （ET-1）, malondialdehyde （MDA） and the activity of superoxide dismutase （SOD）, glutathione peroxidase （GSH-PX） in intestinal mucosa were determined. RESULTS： The intestinal mucosa pathology showed severe damage in model group and low dosage group, slight damage in high dosage group and no obvious damage in normal group. The Chiu＇s score in low dose group and high dose group was significantly lower than that in model group. The content of MDA in model group was higher than that in low and high dose groups, while that in high dose group was almost the same as in normal group. The activity of SOD and GSH-PX was the lowest in model group and significantly higher in high dose group than in normal and low dose groups. The concentrations of LD and ET-1 in model group were the highest. The concentrations of NO in model group and low dose group were significantly lower than those in high dose group and normal group. CONCLUSION： High dose Astraga/us membranaeus has much better protective effect on hemorrhagic shockreperfusion injury of intestinal mucosa than low dose Astragalus membranaceus. The mechanism may be that Astragalus membranaceus can improve antioxidative effect and regulate NO/ET level during hemorrhagic reperfusion.

Efficacy of Liangxue Guyuan decoction(凉血固元汤)on radiation-induced intestinal injury in rats via the toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor-kappa B pathway

OBJECTIVE:To evaluate the efficacy of Liangxue Guyuan decoction(凉血固元汤,LGD)on radiation-induced intestinal injury in rats,and the possible underlying mechanism of action.METHODS:A total of 255 male Sprague-Dawley rats were used.15 rats were assigned to the control group and the remaining 240 rats were exposed to a^(60)Co source at a dose of 11 Gy.Irradiated rats were randomly divided into model,dexamethasone(DXM),low-dose LGD(LGDl),and high-dose LGD(LGDh)groups and treated for 11 d.The survival rate,weight of body,intestinal pathology and the expression of toll-like receptor 4(TLR4),myeloid differentiation primary response 88(MyD88),and nuclear`factor-kappa B(NF-κB)were recorded.RESULTS:Radiation reduced the survival rate and weight of rats,destroyed the intestinal structure,induced an inflammatory reaction,and increased both protein and mRNA expression of TLR4,MyD88,and NF-κB in ileum.However,LGDh increased the survival rate,inhibited weight loss,alleviated inflammation and improve the expression of TLR4 pathway.CONCLUSIONS:LGD increased the survival rate and inhibit weight loss of irradiated rats,and reduced inflammation and intestinal injury.The underlying mechanism may involve regulation of the TLR4/MyD88/NF-κB pathway.

Comparison of the protective effects of resveratrol and pterostilbene against intestinal damage and redox imbalance in weanling piglets

Background: Evidence indicates that early weaning predisposes piglets to intestinal oxidative stress and increases the risk of intestinal dysfunction;however, there are minimal satisfactory treatment strategies for these conditions.This study investigated the potential of resveratrol and its analog, pterostilbene, as antioxidant protectants for regulating intestinal morphology, barrier function, and redox status among weanling piglets.Methods: A total of 144 piglets were selected at 21 days of age and randomly allocated into one of four treatment groups, each of which included six replicates. Piglets in a sow-reared control group were suckling normally between ages 21 and 28 days, while those in weaned groups were fed a basal diet, supplemented with either 300 mg/kg of resveratrol or with 300 mg/kg of pterostilbene. Parameters associated with intestinal injury and redox status were analyzed at the end of the feeding trial.Results: Early weaning disrupted the intestinal function of young piglets, with evidence of increased diamine oxidase activity and D-lactate content in the plasma, shorter villi, an imbalance between cell proliferation and apoptosis, an impaired antioxidant defense system, and severe oxidative damage in the jejunum relative to suckling piglets. Feeding piglets with a resveratrol-supplemented diet partially increased villus height(P = 0.056) and tended to diminish apoptotic cell numbers(P = 0.084) in the jejunum compared with those fed a basal diet. Similarly, these beneficial effects were observed in the pterostilbene-fed piglets. Pterostilbene improved the feed efficiency of weanling piglets between the ages of 21 and 28 days;it also resulted in diminished plasma diamine oxidase activity and D-lactate content relative to untreated weaned piglets(P < 0.05). Notably, pterostilbene restored jejunal antioxidant capacity, an effect that was nearly absent in the resveratrol-fed piglets. Pterostilbene reduced the malondialdehyde and 8-hydroxy-2′-deoxyguanosine contents of jejunal mucosa possibly through its regulatory role in facilitating the nuclear translocation of nuclear factor erythroid-2-related factor 2 and the expression levels of NAD(P)H quinone dehydrogenase 1 and superoxide dismutase 2(P < 0.05).Conclusions: The results indicate that pterostilbene may be more effective than its parent compound in alleviating early weaning-induced intestinal damage and redox imbalance among young piglets.

Resveratrol and its derivative pterostilbene ameliorate intestine injury in intrauterine growth-retarded weanling piglets by modulating redox status and gut microbiota

Background:Intestinal disorder is an important factor contributing to growth lag and high rates of morbidity and mortality of piglets with intrauterine growth retardation(IUGR).Resveratrol(RSV)and its derivative pterostilbene(PT)are natural stilbenes possessing various bioactivities,such as antioxidative and anti-inflammatory effects.This study compared the protective potential of RSV and PT on the intestinal redox status and gut microbiota in weanling piglets with IUGR.Methods:Eighteen male piglets of normal body weight(NBW)and 54 same-sex IUGR piglets were chosen according to their birth and weaning weights.The NBW piglets accepted a basal diet,while the IUGR piglets were allotted to one of three groups according to their body weight at weaning and received a basal diet,an RSV-supplemented diet(300 mg/kg),or a PT-supplemented diet(300 mg/kg),respectively.Results:Compared with IUGR piglets,both RSV and PT improved the IUGR-associated decrease in jejunal villus height and increases in plasma diamine oxidase activity and D-lactate level and jejunal apoptosis of piglets(P<0.05).Administering RSV and PT also enhanced jejunal superoxide dismutase activity and the mRNA and protein expression of superoxide dismutase 2 of IUGR piglets by promoting nuclear factor erythroid 2-related factor 2(Nrf2)nuclear translocation(P<0.05).Comparatively,PT was more effective than RSV in elevating the villus height/crypt depth ratio and occludin mRNA and protein levels in the jejunum of IUGR piglets(P<0.05).PT was also superior to RSV in increasing Nrf2 nuclear translocation and inhibiting malondialdehyde accumulation in the jejunum of IUGR piglets(P<0.05).Additionally,RSV modulated the composition of cecal microbiota of IUGR piglets,as evidenced by increasing the prevalence of the phylum Bacteroidetes and the genera Prevotella,Faecalibacterium,and Parabacteroides and inhibiting the growth of the phylum Proteobacteria and its genera Escherichia and Actinobacillus(P<0.05).Moreover,RSV significantly increased the butyrate concentration in the cecum of IUGR piglets(P<0.05).Conclusion:PT is more potent than RSV to prevent intestinal oxidative stress,while RSV has a stronger capacity to regulate gut microbiota compared to PT.

Muscovite is protective against non-steroidal anti-inflammatory drug-induced small bowel injury

AIM: To evaluate the effect of muscovite in preventing small bowel injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs).

The protective effects of Xuebijing injection on intestinal injuries of mice exposed to irradiation

Background:Gastrointestinal(GI)injury is one of the most common side effects of radiotherapy.However,there is no ideal therapy method except for symptomatic treatment in the clinic.Xuebijing(XBJ)is a traditional Chinese medicine,used to treat sepsis by injection.In this study,the protective effects of XBJ on radiation-i nduced intestinal injury(RⅢ)and its mechanism were explored.Methods:The effect of XBJ on survival of irradiated C57BL/6 mice was monitored.Histological changes including the number of crypts and the length of villi were evaluated by H&E.The expression of Lgr5^(+)intestinal stem cells(ISCs),Ki67^(+)cells,villin and lysozymes were examined by immunohistochemistry.The expression of cytokines in the intestinal crypt was detected by RT-PCR.DNA damage and apoptosis rates in the small intestine were also evaluated by immunofluorescence.Results:In the present study,XBJ improved the survival rate of the mice after 8.0and 9.0 Gy total body irradiation(TBI).XBJ attenuated structural damage of the small intestine,maintained regenerative ability and promoted proliferation and differentiation of crypt cells,decreased apoptosis rate and reduced DNA damage in the intestine.Elevation of IL-6 and TNF-α was limited,but IL-1,TNF-β and IL-10 levels were increased in XBJ-treated group after irradiation.The expression of Bax and p53 were decreased after XBJ treatment.Conclusions:Taken together,XBJ provides a protective effect on RⅢby inhibiting inflammation and blocking p53-related apoptosis pathway.

Effects of penehyclidine hydrochloride on rat intestinal barrier function during cardiopulmonary bypass

AIM:To test the ability of penehyclidine hydrochloride (PHC) to attenuate intestinal injury in a rat cardiopulmonary bypass (CPB) model.METHODS:Male Sprague-Dawley rats were randomly divided into six groups (eight each):sham-operated control;sham-operated low-dose PHC control (0.6 mg/kg);sham-operated high-dose PHC control (2.0 mg/kg);CPB vehicle control;CPB low-dose PHC (0.6 mg/kg);and CPB high-dose PHC (2.0 mg/kg).Blood samples were collected from the femoral artery 2 h after CPB for determination of plasma diamine oxidase (DAO),D-lactate and endotoxin levels.Spleen,liver,mesenteric lymph nodes and lung were removed for biochemical analyses.Intestinal tissue ultrastructure was examined by electron microscopy.RESULTS:In the sham-operated groups,high-and low-dose-PHC had no significant impact on the levels of DAO,D-lactate and endotoxin,or the incidence of intestinal bacterial translocation (BT).Serum levels of DAO,D-lactate,endotoxin and the incidence of intestinal BT were significantly increased in the surgical groups,compared with the sham-operated groups (0.543 ± 0.061,5.697 ± 0.272,14.75 ± 2.46,and 0/40 vs 1.038 ± 0.252,9.377 ± 0.769,60.37 ± 5.63,and 30/40,respectively,all P < 0.05).PHC alleviated the biochemical and histopathological changes in a dosedependent manner.Serum levels of DAO,D-lactate,and endotoxin and the incidence of intestinal BT in the high-dose PHC group were significantly lower than in the low-dose PHC group (0.637 ± 0.064,6.972 ± 0.349,29.64 ± 5.49,and 14/40 vs 0.998 ± 0.062,7.835 ± 0.330,38.56 ± 4.28,and 6/40,respectively,all P < 0.05).CONCLUSION:PHC protects the structure and function of the intestinal mucosa from injury after CPB in rats.

Dynamic changes of IL-2/IL-10, sFas and expression of Fas in intestinal mucosa in rats with acute necrotizing pancreatitis

AIM:To investigate dynamic changes of serum IL-2, IL-10, IL-2/IL-10 and sFas in rats with acute necrotizing pancreatitis. To explore the expression of Fas in intestinal mucosa of rats with acute necrotizing pancreatitis (ANP). METHODS:A total of 64 Sprague-Dawley (SD) rats were randomly divided into two groups:normal control group (C group), ANP group (P group). An ANP model was induced by injection of 50 g/L sodium taurocholate under the pancreatic membrane. Normal control group received isovolumetric injection of 9 g/L physiological saline solution using the same method. The blood samples of the rats in each group were obtained via superior mesenteric vein to measure levels of IL-2, IL-10, sFas and calculate the value of IL-2/IL-10. The levels of IL-2, IL-10 and sFas were determined by ELISA. The severity of intestinal mucosal injury was evaluated by pathologic score. The expression of Fas in intestinal mucosal tissue was determined by immunohistochemistry staining. RESULTS:Levels of serum IL-2 were significantly higher in P group than those of C group (2.79 ± 0.51 vs 3.53 ± 0.62, 2.93 ± 0.89 vs 4.35 ± 1.11, 4.81 ± 1.23 vs 6.94 ± 1.55 and 3.41 ± 0.72 vs 4.80 ± 1.10, respectively, P < 0.01, for all) and its reached peak at 6 h. Levels of serum IL-10 were significantly higher in P group than those of C group at 6 h and 12 h (54.61 ± 15.81 vs 47.34 ± 14.62, 141.15 ± 40.21 vs 156.12 ± 43.10, 89.18 ± 32.52 vs 494.98 ± 11.23 and 77.15 ± 22.60 vs 93.28 ± 25.81, respectively, P < 0.01, for all). The values of IL-2/IL-10 were higher significantly in P group than those of C group at 0.5 h and 2 h (0.05 ± 0.01 vs 0.07 ± 0.02 and 0.02 ± 0.01 vs 0.03 ± 0.01, respectively, P < 0.01, for all), and it were significantly lower than those of C group at 6 h (0.05 ± 0.02 vs 0.01 ± 0.01, P < 0.01) and returned to the control level at 12 h (0.04 ± 0.01 vs 0.05 ± 0.02, P > 0.05). In sFas assay, there was no significant difference between P group and C group (3.16 ± 0.75 vs 3.31 ± 0.80, 4.05 ± 1.08 vs 4.32 ± 1.11, 5.93 ± 1.52 vs 5.41 ± 1.47 and 4.62 ± 1.23 vs 4.44 ± 1.16, respectively, P > 0.05, for all). Comparison of P group and C group, the pathological changes were aggravated significantly in P group. Immunohistochemistry staining show the expression of Fas was absent in normal intestinal tissues, however, it gradually increased after induction of pancreatitis in intestinal tissue, then reached their peaks at 12 h.CONCLUSION:Fas were involved in the pathogenesis of pancreatitis associated intestinal injury. The mechanisms of Fas may be associated to Fas mediated T helper cell apoptosis.

Melatonin protects liver from intestine ischemia reperfusion injury in rats

AIM: To investigate the protective effect of melatonin on liver after intestinal ischemia-reperfusion injury in rats. METHODS: One hundred and fifty male Wistar rats, weighing 190-210 g, aged 7 wk, were randomly divided into melatonin exposure group, alcohol solvent control group and normal saline control group. Rats in the melatonin exposure group received intraperitoneal (IP) melatonin (20 mg/kg) 30 min before intestinal ischemia-reperfusion (IR), rats in the alcohol solvent control group received the same concentration and volume of alcohol, and rats in the normal saline control group received the same volume of normal saline. Serum samples were collected from each group 0.5, 1, 6, 12, and 24 h after intestinal IR. Levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured with an auto-biochemical analyzer. Serum TNF-α was tested by enzyme-linked immunosorbent assay (ELISA). Malondialdehyde (MDA) in liver was detected by colorimetric assay. Pathological changes in liver and immunohistochemical straining of ICAM-1 were observed under an optical microscope. RESULTS: The levels of ALT measured at various time points after intestinal IR in the melatonin exposure group were significantly lower than those in the other two control groups (P < 0.05). The serum AST levels 12 and 24 h after intestinal IR and the ICAM-1 levels (%) 6, 12 and 24 h after intestinal IR in the melatonin exposure group were also significantly lower than those in the other two control groups (P < 0.05). CONCLUSION: Exotic melatonin can inhibit the activity of ALT, AST and TNF-α, decrease the accumulation of MDA, and depress the expression of ICAM-1 in liver after intestinal IR injury, thus improving the liver function.

Cystic fibrosis transmembrane conductance regulator prevents ischemia/reperfusion induced intestinal apoptosis via inhibiting PI3K/AKT/NF-κB pathway

BACKGROUND Intestinal ischemia/reperfusion(I/R)injury is a fatal syndrome that occurs under many clinical scenarios.The apoptosis of intestinal cells caused by ischemia can cause cell damage and provoke systemic dysfunction during reperfusion.However,the mechanism of I/R-induced apoptosis remains unclear.Cystic fibrosis transmembrane conductance regulator(CFTR)is a cAMP-activated chloride channel.Few researchers have paid attention to its role in intestinal I/R injury,or the relationship between CFTR and intestinal apoptosis induced by hypoxia/reoxygenation(H/R).AIM To investigate the effects of CFTR on I/R-induced intestinal apoptosis and its underlying molecular mechanisms.METHODS An intestinal I/R injury model was established in mice with superior mesenteric artery occlusion, and Caco2 cells were subjected to H/R for the simulation of I/R in vivo.RESULTSThe results suggested that CFTR overexpression significantly increased the Caco2 cell viability anddecreased cell apoptosis induced by the H/R. Interestingly, we found that the translocation of p65,an NF-κB member, from the cytoplasm to the nucleus after H/R treatment can be reversed by theoverexpression of CFTR, the NF-κB P65 would return from the nucleus to the cytoplasm asdetermined by immunostaining. We also discovered that CFTR inhibited cell apoptosis in theH/R-treated cells, and this effect was significantly curbed by the NF-κB activator BA, AKTinhibitor GSK690693 and the PI3K inhibitor LY294002. Moreover, we demonstrated that CFTRoverexpression could reverse the decreased PI3K/AKT expression induced by the I/R treatment invivo or H/R treatment in vitro.CONCLUSIONThe results of the present study indicate that the overexpression of CFTR protects Caco2 cells fromH/R-induced apoptosis;furthermore, it also inhibits H/R-induced apoptosis through thePI3K/AKT/NF-κB signaling pathway in H/R-treated Caco2 cells and intestinal tissues.

Impact of intestinal ischemia/reperfusion and lymph drainage on distant organs in rats

AIM:To investigate the impact of intestinal ischemia/reperfusion(I/R) injury and lymph drainage on distant organs in rats.METHODS:Thirty-two Sprague-Dawley male rats,weighing 280-320 g,were randomly divided into blank,sham,I/R,and ischemia/reperfusion and drainage(I/R + D) groups(n = 8).All rats were subjected to 60 min ischemia by clamping the superior mesenteric artery,followed by 120 min reperfusion.The rats in the I/R + D group received intestinal lymph drainage for 180 min.In the sham group,the abdominal cavity was opened for 180 min,but the rats received no treatment.The blank group served as a normal and untreated control.A chromogenic limulus assay kit was used for quantita-tive detection of serum endotoxin.The serum concentrations of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-1β,soluble cell adhesion molecules(sICAM-1),and high mobility group protein box 1(HMGB1) were determined with an enzyme-linked immunosorbent assay kit.Histological evaluations of the intestine,liver,kidney,and lung were performed by hematoxylin and eosin staining and immunohistochemistry.HMGB1 protein expression was assayed by western blot analysis.RESULTS:The serum levels of endotoxin and HMGB1 in the I/R and I/R + D groups were significantly higher than those in the sham group(endotoxin,I/R and I/R + D vs sham:0.033 ± 0.004 EU/mL,0.024 ± 0.003 EU/mL vs 0.017 ± 0.009 EU/mL,respectively,P < 0.05;HMGB1,I/R and I/R + D vs sham:5.473 ± 0.963 EU/mL,4.906 ± 0.552 EU/mL vs 0.476 ± 0.406 EU/mL,respectively,P < 0.05).In addition,endotoxin and HMGB1 were significantly lower in the I/R + D group compared to the I/R group(P < 0.05).The serum inflammatory factors IL-6,IL-1β,and sICAM-1 in the I/R and I/R + D groups were significantly higher than those in the sham group(IL-6,I/R and I/R + D vs sham:41.773 ± 9.753 pg/mL,19.204 ± 4.136 pg/mL vs 11.566 ± 2.973 pg/mL,respectively,P < 0.05;IL-1β,I/R and I/R + D vs sham:144.646 ± 29.378 pg/mL,65.829 ± 10.888 pg/mL vs 38.178 ± 7.157 pg/mL,respectively,P < 0.05;sICAM-1,I/R and I/R + D vs sham:97.360 ± 12.714 ng/mL,48.401 ± 6.547 ng/mL vs 33.073 ± 5.957 ng/mL,respectively;P < 0.05).The serum TNF-α in the I/R group were significantly higher than in the sham group(45.863 ± 11.553 pg/mL vs 18.863 ± 6.679 pg/mL,respectively,P < 0.05).These factors were significantly lower in the I/R + D group compared to the I/R group(P < 0.05).The HMGB1 immunohistochemical staining results showed no staining or apparent injury in the blank group,and slight staining at the top of the microvillus was detected in the sham group.In the I/R group,both the top of villi and the basement membrane were stained for HMGB1 in most areas,and injury in the I/R + D group was less than that in the I/R group.HMGB1 expression in the liver,kidney,and lung of rats in the I/R + D group was significantly lower than the rats in the I/R group(P < 0.05).CONCLUSION:Lymph drainage could block the "gutlymph" pathway,improve intestinal barrier function,and attenuate distant organ injury incurred by intestinal I/R.

Role of intestinal bifidobacteria in the pathogenesis of gut-derived bacteria/endotoxin translocation and the effect of bifidobacterial supplement on gut barrier function following burns

Objective:Early multiple organ dysfunction syndrome appears to be facilitated with bacterial transloca-tion in severely burn injury,yet the mechanisms of bacterial translocation remains in dispute.The aim of this studywas to investigate the potential role of intestinal bifidobacteria in the pathogenesis of gut-derived bacteria/endotoxintranslocation following burns and the effects of bifidohacterial supplement on gut barrier.Methods:Wistar rats wererandomly divided into burn group(Burn,n=60),sham burn g...