The mechanism of intestinal stem cells differentiation after ischemia-reperfusion injury in a rat model.

Purpose: Notch and Wnt/β-catenin signaling are responsible for regulation of intestinal stem cells (ISCs) proliferation and differentiation. The purpose of the study was to evaluate Wnt/β-catenin and Notch signaling roles in regulation of ISC differentiation following ischemia-reperfusion (IR) injury in a rat.

Methods: Rats were assigned into two groups: Sham rats underwent laparotomy without vascular intervention and IR rats underwent occlusion of SMA and portal vein for 20 min followed by 48 h of reperfusion.

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.

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. 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.

Cell death induction (extrinsic versus intrinsic apoptotic pathway) by intestinal ischemia-reperfusion injury in rats is time-depended.

Purpose: We investigate the mechanism of intestinal cell apoptosis and its relation to the time of reperfusion in a rat model of intestinal ischemia-reperfusion (IR).

Methods: Rats were divided into 4 groups: Sham-24 and Sham-48 rats underwent laparotomy without an intentional ischemic intervention and were sacrificed 24 or 48 h hours later; IR-24 and IR-48 rats underwent occlusion of SMA and portal vein for 20 min followed by 24 or 48 h of reperfusion, respectively. Park's injury score, cell proliferation and apoptosis were determined at sacrifice.

Intestinal dysmotility after bowel resection in rats is associated with decreased ghrelin and vimentin expression and loss of intestinal cells of Cajal.

This study provides novel insight into the mechanisms of intestinal dysmotility following massive small bowel resection. We show that 2 wk after bowel resection in rats, impaired intestinal motility was associated with loss of interstitial cells of Cajal (ICC; downregulation of transmembrane member 16A (TMEM16A) and c-kit expression) as well as with decreased vimentin, desmin, and ghrelin levels. Impaired intestinal motility led to a decrease in final body weight, suggesting less effective nutrient absorption.

Anti-TNF-α Therapy Exerts Intestinal Anti-inflammatory and Anti-apoptotic Effects After Massive Bowel Resection in a Rat.

Objectives: The aim of this study was to examine the effect of massive small bowel resection on proinflammatory cytokine intestinal expression and the effect of anti-TNF-α antibodies (ATA) on intestinal inflammation, epithelial cell turnover, and intestinal adaptation after bowel resection in rats.

Methods: Male Sprague-Dawley rats were divided into 4 experimental groups: Sham-rats underwent bowel transection; Sham-ATA rats underwent bowel transection and were treated with ATA; SBS-animals underwent 75% bowel resection; and SBS-ATA rats underwent bowel resection and were treated with ATA similarly to Group B. Parameters of intestinal adaptation, enterocyte proliferation, and apoptosis were determined at sacrifice.

Accelerated Intestinal Epithelial Cell Turnover Correlates with Stimulated BMP Signaling Cascade following Intestinal Ischemia-Reperfusion in a Rat.

Introduction:  Bone morphogenetic proteins (BMPs) are a family of proteins that regulate proliferation and differentiation of intestinal epithelial cells. The purpose of this study was to evaluate the role of BMP signaling following intestinal ischemia-reperfusion (IR) in a rat model.

Materials And Methods:  Male Sprague-Dawley rats were divided into four experimental groups: Sham-24 and Sham-48 rats underwent laparotomy and were sacrificed 24 or 48 hours later, respectively; IR-24 and IR-48 rats underwent occlusion of superior mesenteric artery and portal vein for 30 minutes followed by 24 or 48 hours of reperfusion, respectively.

Repetitive DNA in the Architecture, Repatterning, and Diversification of the Genome of Tausch (Poaceae, Triticeae).

The genome's adaptability to environmental changes, especially during rapid climatic fluctuations, underlies the existence and evolution of species. In the wild, genetic and epigenetic genomic changes are accompanied by significant alterations in the complex nuclear repetitive DNA fraction. Current intraspecific polymorphism of repetitive DNA is closely related to ongoing chromosomal rearrangements, which typically result from erroneous DNA repair and recombination.

Sonic hedgehog signaling controls gut epithelium homeostasis following intestinal ischemia-reperfusion in a rat.

Purpose: One of the major regulators of gastrointestinal tract development is the hedgehog signaling pathway. The purpose of this study was to evaluate the role of sonic hedgehog (SHh) signaling 24 and 48 h following intestinal ischemia-reperfusion (IR) in a rat.

Materials And Methods: Male rats were divided into four experimental groups: (1) Sham-24 h rats underwent laparotomy and were sacrificed after 24 h, (2) Sham-48h rats underwent laparotomy and were sacrificed after 48 h, (3) IR-24h rats underwent occlusion of both superior mesenteric artery and portal vein for 20 min followed by 24 h of reperfusion, and (4) IR-48 h rats underwent ischemia for 20 min followed by 48 h of reperfusion.

Quercetin prevents small intestinal damage and enhances intestinal recovery during methotrexate-induced intestinal mucositis of rats.

Background: Gastrointestinal mucositis occurs as a consequence of cytotoxic treatment. Quercetin (QCT) is a bioflavonoid that exerts significant antioxidant activity and anti-inflammatory as well as anti-malignancy properties.

Objective: To evaluate the effects of oral QCT consumption in preventing intestinal mucosal damage and stimulating intestinal recovery following methotrexate (MTX)-induced intestinal damage in a rat model.

Effect of Pomegranate Juice on Intestinal Recovery Following Methotrexate-Induced Intestinal Damage in a Rat Model.

Background/aims: Several studies have demonstrated the antimicrobial, antihelminthic, and antioxidant potential of the active ingredients of pomegranate (PMG) extracts, suggesting their preventive and curative role in several gastrointestinal disorders. In the present study, the authors evaluated the effects of oral PMG supplementation on intestinal structural changes, enterocyte proliferation, and apoptosis during methotrexate (MTX)-induced intestinal damage in a rat.

Methods: Male rats were divided into 4 experimental groups: control rats; CONTR-PMG rats were treated with oral PMG given by gavage once a day 72 hours before and 72 hours following vehicle injection; MTX rats were treated with single dose of methotrexate; and MTX-PMG rats were treated with oral PMG following injection of MTX.

Effect of N-Acetylserotonin on TLR-4 and MyD88 Expression during Intestinal Ischemia-Reperfusion in a Rat Model.

Background:  Accumulating evidence indicates that changes in intestinal toll-like receptors (TLRs) precede histological injury in a rodent model of necrotizing enterocolitis. N-acetylserotonin (NAS) is a naturally occurring chemical intermediate in the biosynthesis of melatonin. A recent study has shown that treatment with NAS prevents gut mucosal damage and inhibits programmed cell death following intestinal ischemia-reperfusion (IR).

Activated Notch signaling cascade is correlated with stem cell differentiation toward absorptive progenitors after massive small bowel resection in a rat.

Notch signaling is thought to act to drive cell versification in the lining of the small intestine. The purpose of the present study was to evaluate the role of the Notch signaling pathway in stem cell differentiation in the late stages of intestinal adaptation after massive small bowel resection in a rat. Male Sprague-Dawley rats were randomly assigned to one of two experimental groups of eight rats each: Sham rats underwent bowel transection and reanastomosis, while SBS rats underwent 75% small bowel resection.

The Effect of Elevated Intra-Abdominal Pressure on TLR4 Signaling in Intestinal Mucosa and on Intestinal Bacterial Translocation in a Rat.

Background: Recent evidence suggests that elevated intra-abdominal pressure (IAP) may adversely affect the intestinal barrier function. Toll-like receptor 4 (TLR-4) is responsible for the recognition of bacterial endotoxin or lipopolysaccharide and for initiation of the Gram-negative septic shock syndrome. The objective of the current study was to determine the effects of elevated IAP on intestinal bacterial translocation (BT) and TLR-4 signaling in intestinal mucosa in a rat model.

Myxozoan polar tubules display structural and functional variation.

Background: Myxozoa is a speciose group of endoparasitic cnidarians that can cause severe ecological and economic effects. Although highly reduced compared to free-living cnidarians, myxozoans have retained the phylum-defining stinging organelles, known as cnidae or polar capsules, which are essential to initiating host infection. To explore the adaptations of myxozoan polar capsules, we compared the structure, firing process and content release mechanism of polar tubules in myxospores of three Myxobolus species including M.

Effect of Chelerythrine on Intestinal Cell Turnover following Intestinal Ischemia-Reperfusion Injury in a Rat Model.

 Chelerythrine (CHE) is a benzophenanthridine alkaloid that is a potent, selective, and cell-permeable protein kinase C inhibitor. The purpose of the present study was to examine the effect of CHE on intestinal recovery and enterocyte turnover after intestinal ischemia-reperfusion (IR) injury in rats.  Male Sprague-Dawley rats were divided into four experimental groups: (1) sham rats underwent laparotomy, (2) sham-CHE rats underwent laparotomy and were treated with intraperitoneal CHE; (3) IR-rats underwent occlusion of both superior mesenteric artery and portal vein for 30 minutes followed by 48 hours of reperfusion, and (4) IR-CHE rats underwent IR and were treated with intraperitoneal CHE immediately before abdominal closure.

Effect of bowel resection on TLR signaling during intestinal adaptation in a rat model.

Background: Bacterial overgrowth is common complication of short bowel syndrome (SBS) and is a result of an impaired gut barrier function. Toll-like receptor 4 (TLR4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of bowel resection on TLR4 signaling in intestinal mucosa in a rat model.

Effect of N-Acetylserotonin on Intestinal Recovery Following Intestinal Ischemia-Reperfusion Injury in a Rat.

Objective: N-acetylserotonin (NAS) is a naturally occurring chemical intermediate in the biosynthesis of melatonin. Extensive studies in various experimental models have established that treatment with NAS significantly protects heart and kidney injury from ischemia-reperfusion (IR). The purpose of the present study was to examine the effect of NAS on intestinal recovery and enterocyte turnover after intestinal IR injury in rats.

Enhanced intestinal epithelial cell proliferation in diabetic rats correlates with β-catenin accumulation.

The Wnt/β-catenin signaling cascade is implicated in the control of stem cell activity, cell proliferation, and cell survival of the gastrointestinal epithelium. Recent evidence indicates that the Wnt/β-catenin pathway is activated under diabetic conditions. The purpose of this study was to evaluate the role of Wnt/β-catenin signaling during diabetes-induced enteropathy in a rat model.

Effect of ozone on intestinal epithelial homeostasis in a rat model.

Background: The positive effects of ozone therapy have been described in many gastrointestinal disorders. The mechanisms of this positive effect of ozone therapy are poorly understood. The purpose of the present study was to investigate whether the use of ozone may potentiate the gut intestinal mucosal homeostasis in a rat model.

The role of Wnt/β-catenin signaling in enterocyte turnover during methotrexate-induced intestinal mucositis in a rat.

Background/aims: Intestinal mucositis is a common side-effect in patients who receive aggressive chemotherapy. The Wnt signaling pathway is critical for establishing and maintaining the proliferative compartment of the intestine. In the present study, we tested whether Wnt/β-catenin signaling is involved in methotrexate (MTX)-induced intestinal damage in a rat model.

Glutamine attenuates the inhibitory effect of methotrexate on TLR signaling during intestinal chemotherapy-induced mucositis in a rat.

Toll-like receptor 4 (TLR-4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of glutamine (GLN) on TLR-4 signaling in intestinal mucosa during methotrexate (MTX)-induced mucositis in a rat. Male Sprague-Dawley rats were randomly assigned to one of four experimental groups of 8 rats each: 1) control rats; 2) CONTR-GLN animals were treated with oral glutamine given in drinking water (2%) 48 hours before and 72 hours following vehicle injection; 3) MTX-rats were treated with a single IP injection of MTX (20 mg/kg); and 4) MTX-GLN rats were pre-treated with oral glutamine similar to group B, 48 hours before and 72 hours after MTX injection.

Effect of ozone on intestinal recovery following intestinal ischemia-reperfusion injury in a rat.

Background: Growing evidence suggests that ozone (O3) protects the host against pathological conditions mediated by reactive oxygen species by increasing the activity of antioxidant enzymes. The purpose of the present study was to examine the effect of O3 on intestinal recovery and enterocyte turnover after intestinal ischemia-reperfusion (IR) injury in rats.

Methods: Male Sprague-Dawley rats were divided into four experimental groups: (1) sham rats underwent laparotomy; (2) sham-O3 rats underwent laparotomy and were treated with an ozone/oxygen mixture intraperitoneally and intraluminally (50 %/50 %); (3) IR rats underwent occlusion of both superior mesenteric artery and portal vein for 20 min followed by 48 h of reperfusion, and (4) IR-O3 rats underwent IR and were treated with an ozone/oxygen mixture similar to group 2.

Wnt/β-catenin signaling cascade down-regulation following massive small bowel resection in a rat.

Background: Growing evidence suggests that the Wnt/β-catenin signaling cascade is implicated in the control of stem cell activity, cell proliferation, lineage commitment, and cell survival during normal development and tissue regeneration of the gastrointestinal epithelium. The roles of this signaling cascade in stimulation of cell proliferation after massive small bowel resection are unknown. The purpose of this study was to evaluate the role of Wnt/β-catenin signaling during late stages of intestinal adaptation in a rat model of short bowel syndrome (SBS).

Dietary glutamine supplementation prevents mucosal injury and modulates intestinal epithelial restitution following acetic acid induced intestinal injury in rats.

Beneficial effects of glutamine (GLN) have been described in many gastrointestinal disorders. The aim of the present study was to evaluate the preventative effect of oral GLN supplementation against acetic acid (AA) induced intestinal injury in a rat. Male Sprague-Dawley rats were divided into four experimental groups: control (CONTR) rats underwent laparotomy, control-glutamine (CONTR-GLN) rats were treated with enteral glutamine given in drinking water (2%) 48 hours before and five days following laparotomy, AA rats underwent laparotomy and injection of AA into an isolated jejunal loop, and acetic acid-glutamine (AA-GLN) rats underwent AA-induced injury and were treated with enteral GLN 48 hours before and 5 days following laparotomy.

Dietary supplementation with vitamin D stimulates intestinal epithelial cell turnover after massive small bowel resection in rats.

Purpose: While the endocrine action of the active metabolite 1,25-dihydroxyvitamin D (VtD) has been well characterized in relation to the maintenance of plasma calcium and phosphate homeostasis through regulation of intestinal absorption, recent research has focused on its autocrine and/or paracrine activities. Such activities have been best characterized in intestine, where VtD regulates cell differentiation and maturation. The purpose of this study was to evaluate the effect of VtD on enterocyte turnover in a rat model of short bowel syndrome (SBS).