Enterocyte Apoptosis Research Articles

Effect of Plasma Resuscitation with Adjunctive Peritoneal Resuscitation on Hepatic Blood Flow and End-Organ Damage after Hemorrhagic Shock.

Intestinal injury from resuscitated hemorrhagic shock (HS) disrupts intestinal microvascular flow and causes enterocyte apoptosis, intestinal barrier breakdown, and injury to multiple organs. Fresh frozen plasma (FFP) resuscitation or directed peritoneal (DPR) resuscitation protect endothelial glycocalyx, improve intestinal blood flow, and alleviate intestinal injury. We postulated that FFP plus DPR might improve effective hepatic blood flow (EHBF) and prevent associated organ injury (liver, heart). Anesthetized Sprague-Dawley rats underwent HS (40% mean arterial pressure, 60 minutes) and were randomly assigned to groups (n = 8 per group): Sham; crystalloid resuscitation (CR; shed blood + 2 volumes CR); DPR (intraperitoneal 2.5% peritoneal dialysis fluid); FFP (shed blood + 1 vol IV FFP); FFP + DPR. EHBF was measured at postresuscitation timepoints. Organ injury was evaluated by serum ELISA (fatty acid-binding protein [FABP]-1 [liver], FABP-3 [heart], Troponin-I [heart], and Troponin-C [heart]) and hematoxylin and eosin. Differences were evaluated by 1-way ANOVA and 2-way repeated-measures ANOVA. CR resuscitation alone did not sustain EHBF. FFP resuscitation restored EHBF after resuscitation (2 hours, 3 hours, and 4 hours). DPR resuscitation restored EHBF throughout the postresuscitation period but failed to restore serum FABP-1 VS other groups. Combination FFP + DPR rapidly and sustainably restored EHBF and decreased organ injury. CR and DPR alone had elevated organ injury (FABP-1 [hepatocyte], FABP-3 [cardiac], and Troponin-I/C), whereas FFP or FFP + DPR demonstrated reduced injury at 4 hours after resuscitation. HS decreased EHBF, hepatocyte injury, and cardiac injury as evidenced by serology. FFP resuscitation improved EHBF and decreased organ damage. Although DPR resuscitation resulted in sustained EHBF, this alone failed to decrease hepatocyte or cardiac injury. Combination therapy with DPR and FFP may be a novel method to improve intestinal and hepatic blood flow and decrease organ injury after HS/resuscitation.

Exendin-4 inhibits small intestinal glucose sensing and absorption through repression of T1R2/T1R3 sweet taste receptor signalling in streptozotocin diabetic mice

The small intestine, which is the area where sugars are absorbed, should be considered in the approaches developed for the treatment of diabetes. However, studies on small intestine damage in diabetic individuals, and the effects of current treatments on the small intestine are very limited. This is the first study to investigate the effects of exendin-4, a GLP-1 receptor agonist, on small intestine injury in diabetic mice. BALB/c male mice were divided into 4 groups for this study. The first group was given citrate buffer, the second group was given exendin-4, the third group was given streptozotocin (STZ), and the fourth group was given both exendin-4, and STZ. As the results, we determined a decrease in the edema and deterioration in the integrity of the villi, disruption in continuity of the brush border, fibrosis and enterocyte apoptosis, while the TNFα level and crypt cell proliferation were increased in the small intestinal tissue of exendin-4 treated STZ diabetic mice. Furthermore, the levels of duodenal tissue glucose, SGLT1, and GLUT2 were decreased, whereas there was an increase in GIP level in diabetic mice administered with exendin-4. Moreover, we determined that the sweet taste receptors T1R2/T1R3, downstream molecules PLCβ2, α-gustducin and associated secondary messengers IP3, cAMP, which were increased in the duodenal tissue of STZ-diabetic mice, decreased with exendin-4 administration. These findings were evaluated as that exendin-4 reduces glucose absorption by suppressing the T1R2/T1R3 sweet taste signal perception pathway in duodenum of STZ diabetic mice.

Intrauterine Growth Retardation Affects Intestinal Health of Suckling Piglets via Altering Intestinal Antioxidant Capacity, Glucose Uptake, Tight Junction, and Immune Responses.

The aim of the present study was to investigate the effects of intrauterine growth retardation (IUGR) on the intestinal morphology, intestinal epithelial cell apoptosis, intestinal antioxidant capacity, intestinal glucose absorption capacity, and intestinal barrier function of piglets during the suckling period. A total of eight normal-birth-weight (NBW) piglets and eight IUGR newborn piglets (Duroc × Landrace × Yorkshire) were selected from eight litters, one NBW and one IUGR newborn piglet per litter. In each litter, piglets with birth weight of 1.54 ± 0.04 kg (within one SD of the mean birth weight) were selected as NBW piglets and piglets with birth weight of 0.82 ± 0.03 kg (two SD below the mean birth weight) were selected as IUGR piglets. At 21 days of age, all piglets were killed by exsanguinations for sampling. The results showed the body weight (BW) of IUGR piglets on day 0, day 7, day 14, and day 21, and the body weight gain (BWG) of IUGR piglets was significantly lower than that of NBW piglets. IUGR piglets exhibited impaired intestinal morphology, raised enterocyte apoptosis, and increased oxidative damage. It showed that IUGR leads to a lower antioxidant capacity and glucose absorption in the jejunum. In accordance, IUGR caused the intestinal barrier dysfunction by impairing tight junctions and increasing intestinal inflammatory injury. Collectively, these results add to our understanding that IUGR affects intestinal health of suckling piglets via altering intestinal antioxidant capacity, glucose uptake, tight junction, and immune responses, and the slow growth of piglets with IUGR may be associated with intestinal injury.

A Protective Role for Glucagon-like Peptide-2 in Heat-stable Enterotoxin b (STb)-Induced L-Cell Toxicity.

Enterotoxigenic Escherichia coli (ETEC)-derived purified heat-stable enterotoxin b (STb) is responsible for secretory diarrhea in livestock and humans. STb disrupts intestinal fluid homeostasis, epithelial barrier function, and promotes cell death. Glucagon-like peptide-2 (GLP-2) is a potent intestinotrophic hormone secreted by enteroendocrine L cells. GLP-2 enhances crypt cell proliferation, epithelial barrier function, and inhibits enterocyte apoptosis. Whether STb can affect GLP-2 producing L cells remains to be elucidated. First, secreted-His-labeled STb from transformed E coli was collected and purified. When incubated with L-cell models (GLUTag, NCI-H716, and secretin tumor cell line [STC-1]), fluorescent immunocytochemistry revealed STb was internalized and was differentially localized in the cytoplasm and nucleus. Cell viability experiments with neutral red and resazurin revealed that STb was toxic in all but the GLUTag cells. STb stimulated 2-hour GLP-2 secretion in all cell models. Interestingly, GLUTag cells produced the highest amount of GLP-2 when treated with STb, demonstrating an inverse relationship in GLP-2 secretion and cell toxicity. To demonstrate a protective role for GLP-2, GLUTag-conditioned media (rich in GLP-2) blocked STb toxicity in STC-1 cells. Confirming a protective role of GLP-2, teduglutide was able to improve cell viability in cells treated with H2O2. In conclusion, STb interacts with the L cell, stimulates secretion, and may induce toxicity if GLP-2 is not produced at high levels. GLP-2 or receptor agonists have the ability to improve cell viability in response to toxins. These results suggest that GLP-2 secretion can play a protective role during STb intoxication. This work supports future investigation into the use of GLP-2 therapies in enterotoxigenic-related diseases.

Biotin controls intestinal stem cell mitosis and host-microbiome interactions.

Diet is a key regulator of metabolism and interacts with the intestinal microbiome. Here, we study the role of the Drosophila intestinal stem cell (ISC)-specific biotin transporter Smvt in midgut homeostasis, infection-induced regeneration, and tumorigenesis. We show that Smvt-transported biotin in ISCs is necessary for ISC mitosis. Smvt deficiency impairs intestinal maintenance, which can be rescued by the human Smvt, encoded by SLC5A6. ISC-specific, Smvt-silenced flies exhibit microbial dysbiosis, whereby the growth of Providencia sneebia, an opportunistic pathogen, is favored. Dysbiosis correlates with increased Nox expression, reactive oxygen species (ROS), and enterocyte apoptosis. Flies acquire biotin from their diet and microbiota. We show that, when dietary biotin is scarce, biotin-producing commensals, e.g., E.coli, can rescue reduced ISC mitosis. Smvt and commensals also control intestinal tumor growth. Our findings suggest that direct modification of the gut microbiome by biotin can serve as an approach for the treatment of dysbiosis-promoted diseases and tumorigenesis control.

Rhus chinensis Mill. fruits prevent necrotizing enterocolitis in rat pups via regulating the expressions of key proteins involved in multiple signaling pathways

Ethnopharmacological relevanceBased on ancient records and previous studies, many parts of Rhus chinensis Mill., including the fruits, have good preventive and therapeutic effects on inflammation, malaria, diarrhea, and gastrointestinal diseases. Rhus plants and Galla chinensis produced from R. chinensis leaves can also prevent or cure intestinal diseases. However, the preventive effect and molecular mechanisms of R. chinensis fruits on necrotizing enterocolitis (NEC) have not been comprehensively studied. Aim of the studyThis article aims to estimate the effect of the 80% ethanol extract of R. chinensis fruits (RM) on alleviating NEC in rat pups and illustrate the potential molecular mechanisms. Materials and methodsRat pups were subjected to formula feeding, intermittent hypoxic, and cold stresses to establish the NEC model. The preventive effects of RM on NEC were evaluated through survival rate; clinical sickness index; macroscopic conditions; histopathology; and expression levels of inflammatory markers (i.e., tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6]), oxidative stress indicators (i.e., total antioxidant status [TAS], total oxidant status [TOS], superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], myeloperoxidase [MPO], malondialdehyde [MDA]), and tight junction proteins (i.e., Zonula Occludens 1 [ZO-1], Occludin). Moreover, the expression levels of several key proteins involved in oxidative stress (i.e., nuclear factor erythroid 2-related factor 2 [Nrf2], NAD(P)H–quinone oxidoreductase-1 [NQO1]), inflammation (i.e., Toll-like receptor 4 [TLR4], phosphorylated-nuclear factor kappa-B [p-NF-κB], inducible nitric oxide synthase [iNOS]), and apoptosis (i.e., cleaved cysteinyl aspartate specific proteinase-3 [cleaved Caspase-3], Bcl-2-associated X [Bax], B-cell lymphoma-2 [Bcl-2]) in intestinal tissues were analyzed to clarify the molecular mechanisms. ResultsThe extract particularly high doses (400 mg RM/kg body weight) could remarkably reduce the mortality and clinical sickness score and improve the macroscopic condition and histopathological injury of the intestine in NEC pups. After RM administration, the levels of TOS, TNF-α, IL-6, MPO, and MDA in the bowel tissue decreased, whereas the levels of TAS, SOD, and GSH-Px were significantly enhanced. The expression levels of ZO-1 and Occludin proteins were dramatically augmented in RM-treated groups to maintain intestinal barrier integrity. Further analyses revealed that RM might prevent NEC pups by improving some pivotal proteins involved in oxidative stress, inflammation, and apoptosis of enterocytes, namely, by down-regulating the levels of TLR4, p-NF-κB, iNOS, cleaved Caspase-3, and Bax and up-regulating the levels of Bcl-2, NQO1, and Nrf2. ConclusionsThe RM prevented the intestinal inflammation and damage caused by NEC by regulating the expression of several pivotal proteins involved in oxidative stress, inflammation, and apoptosis. This study might provide a scientific basis for R. chinensis fruits as a traditional herbal medicine to prevent and/or alleviate NEC.

L-Isoleucine Administration Alleviates DSS-Induced Colitis by Regulating TLR4/MyD88/NF-κB Pathway in Rats.

Inflammatory bowel disease (namely, colitis) severely impairs human health. Isoleucine is reported to regulate immune function (such as the production of immunoreactive substances). The aim of this study was to investigate whether l-isoleucine administration might alleviate dextran sulfate sodium (DSS)-induced colitis in rats. In the in vitro trial, IEC-18 cells were treated by 4 mmol/L l-isoleucine for 12 h, which relieved the decrease of cell viability that was induced by TNF-α (10 ng/ml) challenge for 24 h (P <0.05). Then, in the in vivo experiment, a total of 44 Wistar rats were allotted into 2 groups that were fed l-isoleucine-supplemented diet and control diet for 35 d. From 15 to 35 d, half of the rats in the 2 groups drank the 4% DSS-adding water. Average daily gain, average daily feed intake and feed conversion of rats were impaired by DSS challenge (P <0.05). Drinking the DSS-supplementing water also increased disease activity index (DAI) and serum urea nitrogen level (P <0.05), shortened colonic length (P <0.05), impaired colonic enterocyte apoptosis, cell cycle, and the ZO-1 mRNA expression (P <0.05), increased the ratio of CD11c-, CD64-, and CD169-positive cells in colon (P <0.05), and induced extensive ulcer, infiltration of inflammatory cells, and collagenous fiber hyperplasia in colon. However, dietary l-isoleucine supplementation attenuated the negative effect of DSS challenge on growth performance (P <0.05), DAI (P <0.05), colonic length and enterocyte apoptosis (P <0.05), and dysfunction of colonic histology, and downregulated the ratio of CD11c-, CD64-, and CD169-positive cells, pro-inflammation cytokines and the mRNA expression of TLR4, MyD88, and NF-κB in the colon of rats (P <0.05). These results suggest that supplementing l-isoleucine in diet improved the DSS-induced growth stunting and colonic damage in rats, which could be associated with the downregulation of inflammation via regulating TLR4/MyD88/NF-κB pathway in colon.

Gut metabolite Urolithin A mitigates ionizing radiation-induced intestinal damage.

Ionizing radiation (IR)‐induced intestinal damage is the major and common injury of patients receiving radiotherapy. Urolithin A (UroA) is a metabolite of the intestinal flora of ellagitannin, a compound found in fruits and nuts such as pomegranates, strawberries and walnuts. UroA shows the immunomodulatory and anti‐inflammatory capacity in various metabolic diseases. To evaluate the radioprotective effects, UroA(0.4, 2 and 10 mg/kg) were intraperitoneally injected to C57BL/6 male mice 48, 24, 1 h prior to and 24 h after 9.0Gy TBI. The results showed that UroA markedly upregulated the survival of irradiated mice, especially at concentration of 2 mg/kg. UroA improved the intestine morphology architecture and the regeneration ability of enterocytes in irradiated mice. Then, UroA significantly decreased the apoptosis of enterocytes induced by radiation. Additionally, 16S rRNA sequencing analysis showed the effect of UroA is associated with the recovery of the IR‐induced intestinal microbacteria profile changes in mice. Therefore, our results determinated UroA could be developed as a potential candidate for radiomitigators in radiotherapy and accidental nuclear exposure. And the beneficial functions of UroA might be associated with the inhibition of p53‐mediated apoptosis and remodelling of the gut microbes.

S3023 Mesenteric Lymphadenopathy From Recurrent Giardiasis: A Rare Cause of Small Bowel Obstruction in a Patient With X Linked Agammaglobulinemia

Introduction: Giardiasis, the most common parasitic infection of the human intestine, is caused by the binucleated protozoan parasite Giardia duodenalis (G intestinalis, giardia lamblia). This infection is commonly reported in developing countries; however, it remains one of the most common parasitic infections in the United States. This infection is also often found in populations with immunodeficiency disorders, such as X Linked agammaglobulinemia. Here, we discuss the case of a patient with X linked agammaglobulinemia who presented with a rare complication of small bowel obstruction (SBO) due to recurrent giardiasis. Case Description/Methods: A 59-year-old male with medical history of X linked agammaglobulinemia, bronchiectasis, COPD, iron deficiency anemia, intestinal malabsorption presented with the complaints of abdominal discomfort and intractable vomiting. The patient also reported similar complaints in the past. Review of systems unremarkable. Initial lab tests revealed leukocytosis (WBC 14.5 K/micro-L), Na 133 mmol/L, K 4.0 mmol/L, BUN 17 mg/dl, Cr 1.17 mg/dl, LFT with in normal limits. X Ray abdomen suggestive of ileus rather than small bowel obstruction. Stool studies positive for calprotectin and lactoferrin. EGD showed giardiasis, colonoscopy biopsies negative for IBD and cancer. CT Abd is unremarkable except for persistent prox. Jejunal luminal narrowing. MR Enterography positive for mesenteric lymphadenopathy causing persistent small bowel obstruction (Fig 1). Discussion: X linked agammaglobulinemia is an inherited immunodeficiency disorder characterized by a failure to produce mature B lymphocytes and antibodies. Because of the lack of antibodies, patients most often present with recurrent upper respiratory tract infections, followed by gastrointestinal infections. Patients with giardiasis present with chronic diarrhea, bloating, nausea and vomiting. Functional dyspepsia, irritable bowel syndrome and cancer are additional intestinal manifestations of giardiasis. The pathophysiology is thought to be due increased enterocyte apoptosis, intestinal barrier dysfunction, malabsorption and increased intestinal transit rates caused by the host’s pathogen immune response. SBO from giardiasis is very rarely reported and has been hypothesized to relate to altered intestinal motility. More research is needed to study the details of the mechanism causing this complication.Figure 1.: Massively distended small bowel loops (shown by orange arrow).

Protection of curcumin to intestinal mucosal barrier by inhibiting enterocyte apoptosis in septic rats

To study the effect of curcumin on enterocyte apoptosis and its protective effect on intestinal mucosal barrier in septic rats. Eighty-seven 3-month male Sprague-Dawley (SD) rats were divided into Sham group, model group and curcumin group by random number table method, with 29 rats in each group. The septic rat model was reproduced by cecal ligation and puncture (CLP). 4 mL dimethyl sulfoxide solution were intraperitoneally injected in both Sham group and model group, 200 mg/kg curcumin dissolved by 4 mL dimethyl sulfoxide solution were intraperitoneally injected in curcumin group 10 minutes after operation. The blood samples (15 rats in each group) were collected 2, 12, 24 hours after operation, and the levels of serum procalcitonin (PCT), tumor necrosis factor-α (TNF-α), D-lactic acid and diamine oxidas (DAO) were tested by enzyme linked immunosorbent assay (ELISA). The ileum tissues were collected 12 hours, 24 hours after operation in three groups, water content was tested by weighting, pathologic structure was observed by light microscope, the enterocyte apoptosis was tested by terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling method (TUNEL). The 7-day survival rate was observed in three groups (14 rats in each group). The serum levels of PCT, TNF-α, D-lactic acid and DAO were higher in model group at 2, 12, 24 hours after operation than those in Sham group, PCT, TNF-α levels were significantly higher in model group than those in Sham group 2 hours after operation [PCT (μg/L): 1.89±0.17 vs. 0.10±0.02, TNF-α (ng/L): 216.51±1.47 vs. 85.25±8.20, both P < 0.01], D-lactic acid, DAO levels were significantly higher in model group than those in Sham group 12 hours after operation [D-lactic acid (mg/L): 40.53±7.76 vs. 11.29±1.28, DAO (ng/L): 1 120.40±302.35 vs. 330.02±81.28, both P < 0.01]. Compared with model group, the levels of serum PCT, TNF-α, D-lactic acid and DAO were lower in curcumin group 2, 12, 24 hours after operation, the statistical difference appeared from 12 hours after operation [PCT (μg/L): 5.37±0.44 vs. 8.67±0.64, TNF-α (ng/L): 211.12±4.31 vs. 313.30±18.46, D-lactic acid (mg/L): 29.74±1.41 vs. 40.53±7.76, DAO (ng/L): 810.71±201.41 vs. 1 120.40±302.35, all P < 0.05], curcumin group had lower water content in ileum tissues 12 hours, 24 hours after operation [(68.34±0.68)% vs. (70.55±0.87)%, (69.41±0.59)% vs. (71.69±0.87)%, both P < 0.05]. The pathologic structures of intestinal villus were normal in Sham group, however, in model group intestinal villus were atrophic, edematous and shorten 12 hours after operation, it was further exacerbated 24 hours after operation. Compared with model group, the pathologic structures of intestinal villus in curcumin group were relived 12 hours, 24 hours after operation. The number of apoptotic enterocytes were significantly increased in model group compared with Sham group 24 hours after operation (cells: 25.48±6.10 vs. 4.00±2.04, P < 0.05), and the number of apoptotic enterocytes was lower in curcumin group than that in model group at the same time (cells: 15.48±3.75 vs. 25.48±6.10), the difference was statistically significant (both P < 0.05). Seven-day survival rate was significantly lower in curcumin than that in model group [42.9% (6/14) vs. 50.0% (7/14)], however, the difference was not statistically significant (P > 0.05). Curcumin can protect the intestinal mucosal barrier by inhibiting enterocyte apoptosis in septic rats.

The Selective 5-HT1A Agonist SR57746A Protects Intestinal Epithelial Cells and Enteric Glia Cells and Promotes Mucosal Recovery in Experimental Colitis.

Neurotrophic growth factors can stabilize the intestinal barrier by preventing the apoptosis of enteric glial cells (EGCs) and enterocytes. We reasoned that a selective 5-HT1A receptor agonist may have neuroprotective properties in the gut and that topical application of SR57746A might be an effective treatment strategy in inflammatory bowel disease (IBD). The therapeutic potential of 5-HT1A receptor agonist SR57746A in IBD was evaluated in vitro (nontransformed NCM460 colonic epithelial cells, SW480 colorectal carcinoma cells) and in vivo (murine dextran sulfate sodium [DSS] colitis and CD4-T-cell transfer colitis). In vitro, we analyzed the effect of SR57746A on apoptosis in intestinal epithelial cells (IECs) and EGCs, and upon proliferation, migration, and intracellular signaling in IECs. In vivo, the effect of topical application of SR57746 on disease activity and on histological and endoscopic findings was compared with intraperitoneal infliximab and placebo, respectively. The SR57746A activates PI3-K/AKT- and ERK-signaling in IECs. Depending on ERK- and AKT activation, SR57746A potently prevents apoptosis of IECs without inducing proliferation or migration in these cells. Moreover, SR57746A prevented apoptosis in EGCs in vitro. Topical SR57746A treatment significantly reduced mucosal injury in 2 experimental murine colitis models and was as effective as intraperitoneal infliximab treatment. Treatment with SR57746A prevents inflammatory cell damage and apoptosis in IECs and EGCs, similar to the neurotrophic effects of EGCs on IECs. Topical treatment with SR57746A could be a candidate for clinical evaluation in the treatment of IBD.

Bridging intestinal failure with Teduglutide - A case report.

Introduction and importanceIntestinal failure (IF) describes the state of a person's gastrointestinal absorption capabilities becoming unable to absorb fluids and nutrients needed to sustain normal physiology, leading to severe comorbidities and if left untreated, to death. IF is most commonly seen as a result of short bowel syndrome (SBS).Teduglutide is a glucagon-like peptide 2 (GLP-2) analogue used in the treatment of patients with SBS and intestinal failure (IF) as a way to reduce the need for parenteral support. Teduglutide leads to the growth of intestinal mucosa by stimulating intestinal crypt cell growth and inhibiting enterocyte apoptosis. It is usually prescribed as a final treatment step after the diagnosis of SBS-IF is made.Case presentationIn this case report we present a novel strategy for using teduglutide as a bridging therapy to intestinal reconstruction. The patient achieved enteral autonomy preoperatively, underwent surgery, and remained in enteral autonomy after intestinal reconstruction.Clinical discussionTeduglutide has been previously exclusively used as continuous therapy in SBS-IF, this is the first reported case of using teduglutide as bridging to intestinal reconstruction. The hypothesis of this approach was to achieve an adequate nutritional status for reconstruction without the disadvantages of parenteral support.ConclusionThe controlled application of teduglutide can provide the benefits of preoperative nutritional optimization without the disadvantages of parenteral support and at the same time facilitate an earlier and easier intestinal reconstruction.

Protective effects of sodium butyrate on rotavirus inducing endoplasmic reticulum stress-mediated apoptosis via PERK-eIF2\u03b1 signaling pathway in IPEC-J2 cells

BackgroundRotavirus (RV) is a major pathogen that causes severe gastroenteritis in infants and young animals. Endoplasmic reticulum (ER) stress and subsequent apoptosis play pivotal role in virus infection. However, the protective mechanisms of intestinal damage caused by RV are poorly defined, especially the molecular pathways related to enterocytes apoptosis. Thus, the aim of this study was to investigate the protective effect and mechanism of sodium butyrate (SB) on RV-induced apoptosis of IPEC-J2 cells.ResultsThe RV infection led to significant cell apoptosis, increased the expression levels of ER stress (ERS) markers, phosphorylated protein kinase-like ER kinase (PERK), eukaryotic initiation factor 2 alpha (eIF2α), caspase9, and caspase3. Blocking PERK pathway using specific inhibitor GSK subsequently reversed RV-induced cell apoptosis. The SB treatment significantly inhibited RV-induced ERS by decreasing the expression of glucose regulated protein 78 (GRP78), PERK, and eIF2α. In addition, SB treatment restrained the ERS-mediated apoptotic pathway, as indicated by downregulation of C/EBP homologous protein (CHOP) mRNA level, as well as decreased cleaved caspase9 and caspase3 protein levels. Furthermore, siRNA-induced GPR109a knockdown significantly suppressed the protective effect of SB on RV-induced cell apoptosis.ConclusionsThese results indicate that SB exerts protective effects against RV-induced cell apoptosis through inhibiting ERS mediated apoptosis by regulating PERK-eIF2α signaling pathway via GPR109a, which provide new ideas for the prevention and control of RV.

Epidermal growth factor receptor inhibitor-induced diarrhea: clinical incidence, toxicological mechanism, and management.

The epidermal growth factor receptor (EGFR) family is a class of receptor tyrosine kinase playing a central role in carcinogenesis and cancer progression. The members of this family, particularly EGFR and human epidermal growth factor receptor 2 (HER2), are the most extensively studied drug targets for malignancy. Today, numerous tyrosine kinase inhibitors targeting EGFR family have been developed to combat non-small-cell lung cancer and breast cancer. However, severe gastrointestinal (GI) toxicity leading to dose reduction and treatment discontinuation hampers the therapeutic outcome of EGFR inhibitors. Diarrhea is one of the most frequent GI side effects, especially when it comes to second-generation EGFR inhibitors. Enterocytes apoptosis and increased inflammation accompany with many oral EGFR inhibitors. Loperamide and budesonide are the first-line treatment to manage such adverse effects. However, current prophylaxis and management are all empirical interventions to relieve the symptom. They do not specifically target the toxicological mechanism of EGFR inhibitors. Hereby, those anti-diarrhea agents do not work well when used in cancer patients experiencing EGFR inhibitor-induced diarrhea. On the other hand, the toxicological mechanism of EGFR inhibitor-induced diarrhea is poorly understood. Thus, determining the mechanism behind such diarrhea is urgently in need for developing genuinely effective anti-diarrhea agents. This review aims to call attention to EGFR inhibitor-induced diarrhea, a highly occurring and devastating cancer drug toxicity.

Dietary dihydroartemisinin supplementation alleviates intestinal inflammatory injury through TLR4/NOD/NF-κB signaling pathway in weaned piglets with intrauterine growth retardation.

The aim of present study was to evaluate whether diets supplemented with dihydroartemisinin (DHA) could alleviate intestinal inflammatory injury in weaned piglets with intrauterine growth retardation (IUGR). Twelve normal birth weight (NBW) piglets and 12 piglets with IUGR were fed a basal diet (NBW-CON and IUCR-CON groups), and another 12 piglets with IUGR were fed the basal diet supplemented with DHA at 80 mg/kg (IUGR-DHA group) from 21 to 49 d of age. At 49 d of age, 8 piglets with similar body weight in each group were sacrificed. The jejunal and ileal samples were collected for further analysis. The results showed that IUGR impaired intestinal morphology, increased intestinal inflammatory response, raised enterocyte apoptosis and reduced enterocyte proliferation and activated transmembrane toll-like receptor 4 (TLR4)/nucleotide-binding and oligomerization domain (NOD)/nuclear factor-κB (NF-κB) signaling pathway. Dihydroartemisinin inclusion ameliorated intestinal morphology, indicated by increased villus height, villus height-to-crypt depth ratio, villus surface area and decreased villus width of piglets with IUGR (P < 0.05). Compared with NBW piglets, IUGR piglets supplemented with DHA exhibited higher apoptosis index and caspase-3 expression, and lower proliferation index and proliferating cell nuclear antigen expression in the intestine (P < 0.05). Dihydroartemisinin supplementation attenuated the intestinal inflammation of piglets with IUGR, indicated by increased concentrations of intestinal inflammatory cytokines and lipopolysaccharides (P < 0.05). In addition, DHA supplementation down-regulated the related mRNA expressions of TLR4/NOD/NF-κB signaling pathway and upregulated mRNA expressions of negative regulators of TLR4 and NOD signaling pathway in the intestine of piglets with IUGR (P < 0.05). Piglets in the IUGR-DHA group showed lower protein expressions of TLR4, phosphorylated NF-κB (pNF-κB) inhibitor α, nuclear pNF-κB, and higher protein expression of cytoplasmic pNF-κB in the intestine than those in the IUGR-CON group (P < 0.05). In conclusion, DHA supplementation could improve intestinal morphology, regulate enterocyte proliferation and apoptosis, and alleviate intestinal inflammation through TLR4/NOD/NF-κB signaling pathway in weaned piglets with IUGR.

Роль неинвазивных маркеров повреждения энтероцитов и повышенной проницаемости в патогенезе целиакии

Celiac disease (CD) is an immune-mediated enteropathy characterized by atrophy/damage to the mucous membrane of the small intestine in genetically susceptible individuals in response to gluten administration. In CD morphology, atrophy is the result of increased enterocyte apoptosis due to autoimmune inflammation. Since the enterocyte is an anatomical and functional unit of the mucous membrane of the small intestine, responsible for the barrier function and for the absorption of nutrients, to understand the pathogenesis of CD, the study of the processes of restoration of the mucosa is of paramount importance. Antibodies to tissue transglutaminase, antibodies to deamidated gliadin peptides, antibodies to endomysium, which are used to monitor disease activity and represent the body's immune response, can only indirectly indicate the degree of damage/recovery of enterocytes. During histological examination it is not always possible to assess the degree of damage at the cellular level, taking into account the complexity of the interpretation of morphological changes and patchiness of mucosa damage. In recent years, researchers have paid much attention to new markers of mucosa permeability, which include: I-FABP − a marker reflecting damage to enterocytes, citrulline − a marker of the functional mass of enterocytes, zonulin − a marker of increased mucosa permeability and alpha-1-antitrypsin − a marker reflecting the failure of the barrier function of the small intestine and protein loss. Using of these markers will help optimize the algorithm for non-invasive diagnostics of CD, improve monitoring of disease activity, and will also usefull for understanding the processes of mucosa recovery.

Kampo medicines Rikkunshito and Hangeshashinto prevent cisplatin-induced intestinal mucosal injury in rats

Background/PurposeWe examined the effects and mechanisms of rikkunshito (RKT) and hangeshashinto (HST) on cisplatin-induced mucosal injuries in the rat small bowel. MethodsJuvenile rats were divided into 6 groups: sham control, cisplatin injection without kampo medicines, and cisplatin injection with oral administration of low and high doses of RKT (1000 mg/kg and 2000 mg/kg) and HST (500 mg/kg and 1000 mg/kg). Fecal condition, intestinal morphological changes, enterocyte proliferation, and enterocyte apoptosis were assessed. ResultsDiarrhea and atrophy of ileal villi observed in the cisplatin group were significantly improved in all kampo groups. Injury scores of the jejunum were significantly lower with RKT (2000 mg/kg) and HST (500 and 1000 mg/kg) than with cisplatin, and those of the ileum were significantly lower with HST (500 and 1000 mg/kg) than with cisplatin. Enterocyte proliferation of the jejunum was significantly increased with RKT (2000 mg/kg) and HST (500 mg/kg) compared with cisplatin, and those of the ileum were significantly increased in all kampo groups compared with the cisplatin group. Jejunal and ileal apoptosis following cisplatin administration was significantly inhibited by HST. ConclusionsRKT and HST prevented cisplatin-induced intestinal mucosal injury with increasing proliferation of intestinal epithelial cells. HST also attenuated cisplatin-induced crypt cell apoptosis.

Biotin Controls Intestinal Stem Cell Mitosis and Host-Microbiome Interactions

Detrimental alterations in intestinal microbiota, known as dysbiosis, predispose to inflammation that can lead to tumorigenesis. We show that dysbiosis can also result from impaired intestinal stem cell (ISC) metabolism. We found that the Drosophila intestinal ISC-specific biotin transporter Smvt is necessary for Jak/Stat pathway-mediated ISC mitosis. ISC-specific Smvt silencing impairs intestinal maintenance, which can be partially-rescued by the human Smvt, encoded by SLC5A6. Smvt-deficient flies exhibit microbial dysbiosis, whereby the growth of Providencia sneebia, an opportunistic pathogen, is favored. Dysbiosis correlates with increased Nox expression, ROS and enterocyte apoptosis. Flies acquire biotin from their diet and microbiota. We found that when dietary biotin is scarce, biotin-producing commensals, e.g. E. coli, can rescue reduced ISC mitosis. Smvt and commensals also control intestinal tumor growth. Our findings suggest that direct modification of the gut microbiome by biotin can serve as an approach for the treatment of dysbiosis-promoted diseases and tumorigenesis control.

The Mechanisms of the Anti-Inflammatory and Anti-Apoptotic Effects of Omega-3 Polyunsaturated Fatty Acids during Methotrexate-Induced Intestinal Damage in Cell Line and in a Rat Model.

Background: The aim of this study was to examine the anti-inflammatory and anti-apoptotic patterns of omega-3 polyunsaturated fatty acids (n-3 PUFAs) during methotrexate (MTX) induced intestinal damage in cell culture and in a rat model. Methods: Non-treated and treated with MTX HT 29 and HCT116cells were exposed to increasing doses of n-3 PUFAs and cell viability was evaluated using PrestoBlue® assay. Male Sprague-Dawley rats were divided into 4 experimental groups: Control rats, CONTR+n-3 PUFA rats that were treated with oral n-3 PUFA, MTX rats were treated with MTX given IP, and MTX+n-3 PUFA rats were treated with oral n-3 PUFA before and following injection of MTX. Intestinal mucosal parameters and mucosal inflammation, enterocyte proliferation and apoptosis, TNF-α in mucosal tissue and plasma (ELISA), NF-κB, COX-2, TNF-α, Fas, FasL, Fadd, Bid, Bax and Bcl-2gene and protein levels were determined 72 h following MTX injection. Results: Exposure of HT 29 and HCT116cells to n-3 PUFA attenuated inhibiting effects of MTX on cell viability. MTX-n-3 PUFA rats demonstrated a lower intestinal injury score and enhanced intestinal repair. A significant decrease in enterocyte apoptosis in MTX+n-3 PUFA rats was accompanied by decreased TNF-α, FAS, FasL, FADD and BID mRNA levels. Decreased NF-κB, COX-2 and TNF-α levels in mucosa was accompanied by a decreased number of IELs and macrophages. Conclusions: n-3 PUFAs inhibit NF-κB/COX-2 induced production of pro-inflammatory cytokines and inhibit cell apoptosis mainly by extrinsic pathway in rats with MTX-induced intestinal damage.

Human antigen R (HuR) and Cold inducible RNA-binding protein (CIRP) influence intestinal mucosal barrier function in ulcerative colitis by competitive regulation on Claudin1.

To investigate the effects of RNA-binding proteins cold-inducible RNA binding protein (CIRP) and human antigen R (HuR) on expression of Claudin1 and mucosal barrier function in ulcerative colitis (UC). The clinical specimens of UC patients and healthy volunteers were collected. In the clinical experiments, the expressions of CIRP, Claudin1, and HuR, along with their correlations in tissues of UC patients were analyzed by qRT-PCR, Western blot and Pearson correlation coefficient, respectively. The chi-square test was utilized to assess the relevance between CIRP/HuR/Claudin1 level and clinicopathological characteristics of UC patients. The in vitro and in vivo models of UC were established by lipopolysaccharide treatment or dextran sulfate sodium injection. For cell experiments, after loss- and gain-of-function, the roles of CIRP or HuR in the apoptosis and proliferation of enterocytes were examined by flow cytometry and CCK-8 assay. The intestinal epithelial barrier function was inspected after determination on transepithelial electrical resistance value, horseradish peroxidase permeability and expressions of tight junction proteins (Occludin, ZO-1, and JAM-1). The relationship between HuR, CIRP, and Claudin1 was performed by RNA immunoprecipitation and dual-luciferase reporter gene assay. For in vivo experiments, the disease activity index score, weight loss and colon length of mice were assessed to observe the effect of CIRP or HuR on the UC mouse models. Histological analysis of colon tissues was conducted by H&E staining. FITC-dextran tracking was applied to inspect the intestinal mucosal barrier function of UC mouse models. In this study, high expression of CIRP and low expressions of HuR and Claudin1 were observed in patients, cells and mouse models of UC. The expressions of CIRP, HuR, and Claudin1 were correlated with the severity of patients with UC. There was a negative correlation between CIRP and Claudin1, and as a positive correlation between HuR and Claudin1. Claudin1 can be suppressed by CIRP, while enhanced by HuR. HuR and CIRP can competitively bind to Claudin1. HuR upregulation or CIRP downregulation promoted proliferation, suppressed apoptosis and ameliorated the damage of the barrier function in enterocytes. The in vivo experiments verified that the ameliorated damage of the intestinal mucosal barrier function in UC mice occurred with HuR overexpression or CIRP knockdown. CIRP and HuR confer pivotal effect on the intestinal mucosal barrier function of UC through competitively binding to Claudin1 mRNA.