Mucosal Crypt Research Articles

Keratinocyte growth factor pretreatment prevents radiation-induced intestinal damage in a mouse model

Background. Radiation-induced gastrointestinal syndrome is usually severe in clinical practice. Keratinocyte growth factor (KGF) plays an important role in the intestinal mucosal growth and repair of intestinal injury. This study was to investigate the effects of KGF on radiation-induced intestinal damage, especially the barrier dysfunction, in a mouse model. Methods. Adult C57BL/6J mice were randomized into three groups: normal control, irradiation group, and KGF-treated group. Mice in the later two groups received irradiation with a dose of 6 Gy from Co-60 source. In the KGF-treated group, KGF was intraperitoneally given once daily (5 mg/kg/day) for 5 consecutive days before irradiation. Mice were killed at 3 days after irradiation and the small bowel was collected for histology. Epithelial cell proliferation was studied by immunohistochemistry for proliferating cell nuclear antigen. Claudin-1 and ZO-1 expressions were determined by western blot assay and immunohistochemistry. Epithelial barrier function was assessed with transepithelial resistance. Results. KGF significantly promoted the recovery of mucosa from radiation-induced injury demonstrated by mucosal histology, villus height, crypt depth, and crypt cell proliferation. KGF also improved the disrupted distribution of tight junction proteins and the epithelial barrier dysfunction after irradiation. Conclusion. KGF pretreatment could improve radiation-induced intestinal injury including the epithelial structure and function in a mouse model.

Gallbladder Stem/progenitor cells are able to repopulate and rescue the damaged liver in a experimental mouse model of liver cirrhosis

The human biliary tree contains stem cells within peribiliary glands (Cardinale et al., 2011). Human Gallbladder contains stem/progenitors (hGSCs) located in mucosal crypts (Carpino et al., 2012). Our aim was to evaluate the capability of hGSCs to repopulate and rescue the damaged liver in a model of liver cirrhosis. hGSCs were selected for Epithelial Cell Adhesion Molecule. Cirrhosis was induced by intraperitoneal injection, twice a week, of carbon tetrachloride for 7 weeks. hGSCs were injected into the liver via the spleen of normal or cirrhotic SCID mice. As controls, cirrhotic SCID mice were injected only with the medium or with mature human hepatocytes. 2 months after the injection, the necrotic areas were lower in mice treated with hGSCs in comparison with controls. In hGSCs-injected cirrhotic mice, the expression of the human antigens indicated that ≈10% of the host hepatocyte mass was represented by in vivo differentiated human hepatocytes derived from injected hGSCs. This value was significantly higher with respect to mice injected with human adult hepatocytes. The presence of human cells in murine livers was confirmed by in situ hybridization for human chromosomes. hGSCs injection dictated an improvement of serum liver biochemistry with a significant reduction of transaminases and an improvement of synthetic functions. In this model, hGSC engraftment and differentiation determinate the improvement of histological liver damage and serum liver biochemistry. These data could open future perspectives for a role of gallbladder as a source of stem cells for liver regenerative medicine.

Magnifying Endoscopic Findings Can Predict Clinical Outcome during Long-Term Follow-Up of More Than 12 Months in Patients with Ulcerative Colitis

Background and Aims. To explore the association of magnifying endoscopic (ME) findings with histopathology and relapse in ulcerative colitis (UC). Methods. Forty-six patients with UC underwent ME with narrow band imaging (NBI) and crystal violet staining and were followed for more than 12 months. ME findings with vital staining were classified into ME-A, regular arrangement of round to oval pits; ME-B, irregular arrangement with/without enlarged spaces between even pits; ME-C, irregular pits in size and shape with more irregular arrangement of pits; and ME-D, disrupted or disappeared pits. NBI-guided ME features of microvascular pattern (MVP) were divided into the MVP-regular and MVP-irregular type. Results. There were 5, 24, 10, and 7 cases of ME-A, ME-B, ME-C, and ME-D grade, respectively, while there were 21 and 25 of MVP-regular and MVP-irregular type, respectively. ME classifications were significantly associated with Matts endoscopic grade. ME classifications and MVP types were significantly associated with each pathognomonic microscopic feature of severe mucosal inflammation, crypt abscess, and goblet cell depletion. There were significant differences in the percentages of remission among ME classifications and between MVP types. Conclusion. ME findings can be predictive of relapse in UC and reliable for in vivo histopathological assessment.

<i>Helicobacter</i> infection decreases basal colon inflammation, but increases disease activity in experimental IBD

Background: Helicobacter species are best known for their roles in the pathology of gastritis; however, several Helicobacter species also colonize the intestine, and less is known about effects of Helicobacter on the development of intestinal inflammation. To evaluate contributions of Helicobacter in inflammatory bowel disease, we investigated whether and how pre-existing intestinal colonization would affect disease severity and biomarkers of inflammation in experimental IBD. Materials and Methods: Mice were infected with H. muridarum 2 weeks prior to induction of colitis mediated by 3% dextran sulfate (DSS). Disease activity index, stool blood and consistency, colon length, myeloperoxidase, histopathology, blood and lymphatic vessels, and numbers of dilated mucosal crypts were measured in control, DSS-only, H. muridarum-infected, and H. muridarum-infected + DSS mice. Results: Prior to DSS challenge, H. muridarum-infected mice showed little distal gut injury by several indices of colon inflammation with decreased blood vessel density in the submucosa, and lower lymphatic density in the mucosa and submucosa. However, after DSS colitis, H. muridarum-infected mice exhibited significantly greater disease. Weight change, stool bleeding, diarrhea, and angiogenesis were all increased in H. muridarum-infected mice in DSS colitis compared to DSS controls. Conclusions: Our data show that Helicobacter colonization of the intestine, unlike that of the stomach, lowers basal gut inflammatory scores, but increases disease activity and inflammation in an acute colitis model. Intestinal Helicobacter infection may therefore represent a significant sub-clinical factor which predisposes the gut to inflammatory injury.

Clinical significance of white gastric crypt openings observedviamagnifying endoscopy

To evaluate the relationship between Helicobacter pylori (H. pylori)-induced gastritis and white gastric mucosal crypt openings (COs) in the gastric corpus. A total of 175 consecutive patients (including 69 patients with gastric cancer) were enrolled in this study. We used magnifying endoscopy (ME) to observe the mucosa microsurface of the lesser and greater curvature of the gastric corpus (350 areas in all). We focused on areas with a round pit microstructure (primarily observed in non-atrophied areas) and evaluated the white openings of these gastric pits. We classified the whiteness of the COs as the "white-edged dark spot" type (consisting of a dark spot bordered by white); the "white" type (pure white with no dark spot); and the "dense white pit (DWP)" type (dense white, resembling a snowball). Gastritis was also histologically evaluated according to the updated Sydney System. We detected round COs using ME in 246 of the 350 areas examined. The histological examination showed significantly more mononuclear cells and neutrophil infiltration in the "white" and "DWP" types than the "white-edged dark spot" type (P < 0.001). Furthermore, significantly high-grade inflammation and evidence of active H. pylori-induced gastritis was observed in the "DWP" type (P < 0.001). Significant differences were observed in the whiteness of COs between H. pylori-positive (n = 139) and negative (n = 36) patients (P < 0.001). The sensitivity and specificity of the "white" and "DWP" types for predicting H. pylori infection were 78.5% and 81.7%, respectively. Of the patients with gastric cancer, 22.5% (18/80) had "white-edged dark spots", 51.3% (41/80) had "white" COs, and 26.3% (21/80) had "DWP"-type COs. "DWPs" were frequently observed among patients with undifferentiated gastric cancer [45.7% (16/35)]. CO whiteness detected via ME was associated with histological evidence of gastritis and helps to predict the severity of inflammation and H. pylori-induced activity.

Stimulating effect of pancreatic-like enzymes on the development of the gastrointestinal tract in piglets1

Use of nutritional components from the milk and eventually from the solid feed relates to the growth and development of gastrointestinal tract (GIT). We studied the effect of pancreatic-like enzymes [porcine pancreatic enzymes (Creon) or microbial-derived amylase, protease, and lipase] on GIT morphology and lipid absorption in suckling piglets. Both enzyme preparations, in low or high dose, were fed via a stomach tube twice a day for 7 d starting at 8 d of age and controls received vehicle, n = 6. The day after treatments ended, lipid absorption was tested after which pigs were euthanized and GIT was examined. Enzyme cocktails, irrespective of their origin, increased (P < 0.001) triglyceride level in blood. Enzyme preparation affected (P < 0.001) small intestinal mucosal thickness, villi length, and crypt depth and (P < 0.01) mitotic division of enterocytes. In addition, the external administration of pancreatic enzymes stimulated pancreatic growth as observed by increased (P < 0.05) mitotic division of pancreatic cells. The study revealed that pancreatic or pancreatic-like enzymes of microbial origin administrated in the early postperinatal period enhance GIT development and may be used to better prepare the GIT of piglets for milk use and weaning.

Inhibition of the mTOR Pathway Alleviates Intestinal Fibrosis Via Suppression of Myofibroblast Proliferation

Intestinal fibrosis is generally considered to be an irreversible stage which gradually evolves in response to prolonged injury or inflammation. The pathophysiology of intestinal fibrosis in IBD is not fully understood. Rapamcyin, an inhibitor of mTOR, has recently been reported to alleviate a severe form of IBD, presumably by improving the inflammatory response by down-regulating the immune system. Recent studies suggest that the mTOR signaling pathway may be involved in transforming growth factor β1(TGFβ1)-dependent fibrogenic processes in several organ systems. Low-dose oral administration of rapamycin reduces fibrogenesis, improves liver function, and prolongs survival in rats with established liver cirrhosis. We hypothesized that rapamycin ameliorates intestinal fibrosis via inhibition of submucosal myofibroblast proliferation. Mice were divided into four groups including control, TNBS alone, rapamycin alone, and both rapamycin and TNBS. Rapamycin (5 mg/kg/day) was administrated intraperitoneally for 6 weeks and TNBS enema weekly for 6 weeks to induce intestinal fibrosis. Mouse colon samples were collected for examination of submucosal collagen deposition by Masson's trichrome blue and myofibroblast proliferation by either aSMA or HIT-5 (focal adhesion protein hydrogen peroxide inducible clone 5). Isolated primary intestinal cells or smooth muscle cell line was treated with TGFβ1 for 72 hours either with or without rapamycin. Myofibroblast cells were identified by staining with aSMA. Colon samples harvested from TNBS-treated mice displayed severe stricture over the distal colon while only mild, patchy erythema and edema observed in the rectum from rapamycin treated TNBS group. While being completely distorted in vehicle treated TNBS group, mucosal crypt architecture was largely preserved in rapamycin treated TNBS group. Colon thickness is an indirect measurement of intestinal inflammation and fibrosis. TNBS treatment induced overall thickening of the colon tissue, especially in the submucosa and muscularis layers, which was markedly prevented by rapamycin treatment. Furthermore, we observed the presence of hyperproliferation of myofibroblasts (aSMA and Hic-5 positive cells) along with significant collagen deposition in the intestine from TNBS treated group. In contrast, intestine from rapamycin treated group exhibited very mild proliferation of myofibroblasts and deposition of collagen. Direct effect of rapamycin on myofibroblast proliferation was also examined in primary intestinal cells and smooth muscle cell line. We observed that rapamycin markedly inhibited proliferation of aSMA and Hic-5 positive cells elicited by TGF-β1in primary intestinal cell cultures. Rapamycin ameliorates intestinal fibrosis in TNBS mouse model. Our in vitro data suggest that rapamycin exerts anti-fibrotic effect in part via direct suppression of myofibroblast proliferation. These findings may have preventive or therapeutic applications in fibrotic Crohn disease.

Hematological Abnormalities in Aged Telomerase RNA Component Deficient Mice Are Associated with Intestinal Epithelial Degeneration and Bone Marrow Stromal Dysfunction

AbstractAbstract 1244Mice carrying germline deletion of the telomerase RNA component (Terc−/−) have functional alterations in various tissues but can breed and live normally for six generations. We acquired Terc−/− mice at G3 generation under the C57BL/6 (B6) background, backcrossed to normal inbred B6 mice, interbred between Terc+/− offspring to generate Terc−/−, Terc+/− and Terc+/+ mice at later generations, and analyzed cytological changes in hematological tissues using animals at young (3–6 months), middle (12–18 months) and old (20–26 months) ages. Cellular composition was relatively normal in peripheral blood (PB), bone marrow (BM) and spleen in young Terc−/− and Terc+/− mice relative to Terc+/+ littermates. However, middle and old Terc−/− mice had significantly lower levels of red blood cells, hemoglobin and hematocrit, and significantly higher percentage red cell distribution width and neutrophil counts in comparison to old Terc+/+ mice and young B6 controls. Middle and old Terc−/− mice also showed typical signs of lineage bias with significantly higher CD11b cell percentage and significantly lower CD45R cell percentage in BM, PB and spleen. Interestingly, BM cells from middle and old Terc−/− mice contained higher percentage and total number of Lin−Sca1+Kit+CD150+ hematopoetic stem and progenitor cells than those from young Terc−/− and young B6 controls. Transplantation of old Terc−/− BM cells into lethally irradiated young B6 recipients resulted in effective donor cell engraftment with relatively normal levels of blood cell counts and normal CD11b and CD45R cell percentages at four to twelve months after transplantation, indicating that the anemia, neutrocytosis and hematopoietic lineage bias seen in aged Terc−/− mice were not intrinsic to hematopoietic stem or progenitor cells. We therefore hypothesize that the age-related hematological abnormalities in Terc−/− mice were responses secondary to inflammatory stresses, or were results of BM stromal dysfunction, or both.Since hematological abnormalities were easily detectable in middle Terc−/− (12–18 months) mice, we used animals of this age group in our future studies. Middle Terc−/− mice were smaller in size compared to littermates, lethargic, in a hunched posture, and produced a soft stool instead of fecal pellets. At necropsy, the walls of the ileum, cecum and colon were thickened; the ceca were diminished in size, and the cecal and colonic digesta was soft and pasty. Histologic changes in the small intestine, cecum and colon consisted of dysplastic mucosal epithelium with anisocytosis, cytomegaly, and karyomegaly. The small intestinal villi were blunted and fused. Mucosal crypts were lost in the small intestine, cecum and colon along with mucosal ulceration, epithelial attenuation and bacterial colonization of ulcerated areas. There was marked suppurative intestinal inflammation along with severe enteritis, typhlitis and colitis (Figure 1, A & B). In these same animals, BM hematopoiesis was dominated by myeloid precursors with a sharp decline in the presence of erythroid precursors (Figure 1, C & D). In the skin sections, the vast majority of hair follicles were in telogen, a resting phase, and were located close to the epidermis with few sebaceous glands around the hair follicle. Liver, heart, lung and kidney were relatively normal based on microscopic examinations. We analyzed plasma concentrations of selected hematopoietic cytokines and found insignificant declines in GM-CSF and IL-3 and significant increases in G-CSF and IL-6 in middle Terc−/− mice. Flow cytometry analyses revealed a lower percentage of CD3−CD11b−CD45R−CD44+Sca1+ stromal cells in the BM of middle Terc−/− animals. Culturing middle Terc−/− BM cells in vitro in alpha-modified eagle media at 33 degrees for two weeks resulted in the development of stromal feeder layers with normal morphological appearance but reduced functional efficacy to support cobblestone colony formation from freshly-overlaid normal B6 BM cells. We conclude that constitutional Terc deficiency in middle and old Terc−/− mice causes obvious intestinal epithelia degeneration and severe intestinal inflammation that adversely affects normal hematopoiesis to result in neutrocytosis, anemia and lineage bias disfavoring B cells. Dysfunction of BM stromal cells might also contribute to hematological abnormalities in aged Terc-deficient animals. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Effects of hexavalent chromium on reproductive functions of male adult rats

Hexavalent chromium is an environmental contaminant which may be associated with reproductive abnormalities in male rats. In the present study, we examined the effect of hexavalent chromium on male reproductive function of rats. Male Wistar rats received a daily intraperitoneal injection of potassium dichromate (1 or 2 mg/kg body weight) for fifteen consecutive days. A decrease in testis weight and an increase in seminal vesicles and prostate weights were demonstrated after chromium treatment. Moreover, a dose-dependent increase in blood and testis chromium levels as well as an increase in FSH and a decrease in LH and testosterone serum levels were detected in treated rats. Histological analysis revealed pronounced morphological alterations with enlarged intracellular spaces, tissue loosening and dramatic loss of gametes in the lumen of the seminiferous tubules of treated rats. In addition, a decreased sperm motility and number of epididymal spermatozoa together with an increased sperm abnormality rate was found in chromium-treated rats in comparison to controls. In rats receiving the higher chromium dose, histological images presented considerably increased areas filled with seminal vesicle and prostate secretions. The mucosal crypts of seminal vesicles and the typical invaginations of prostate were altered. The results suggest that subacute treatment of potassium dichromate promotes reproductive system toxicity and affects testicular function of adult male rats.

Schistosomiasis May Contribute To Goblet Cell Carcinoid of the Appendix

Abstract : To investigate whether schistosomiasis can contribute to appendiceal goblet cell carcinoid, appendix samples were obtained from 3 patients with combined appendiceal schistosomiasis and goblet cell carcinoid (CSG), 6 patients with goblet cell carcinoid only (GCC), 12 patients with appendiceal schistosomiasis only (ASO), and 12 cases with normal appendix (NA), all of similar gender ratio and age distributions. Hematoxylin and eosin-(H&E) stained sections were studied in 3 CSGs and 12 ASOs to diagnose schistosomiasis by detecting schistosome eggs. H&E and alcian blue/PAS-stained sections and immunohistochemistry of CgA and CEA were employed to establish the diagnosis of GCC in the 3 CSGs and 6 GCCs. Then, to determine whether schistosomiasis can contribute to GCC, immunostaining patterns of CgA and Ki67 in mucosal crypt epithelia were investigated and compared among all 33 cases. Our results revealed typical histological and immunohistochemical phenotypes of GCC in the 3 CSGs and 6 GCCs and schistosome egg deposits in 3 CSGs and 12 ASOs. We found that the expression levels of both CgA and Ki67 in mucosal crypt epithelia were significantly higher in CSG than in GCC (P < 0.05 = 0.013 and P = 0.004, respectively). Moreover, high expression levels of both CgA and Ki67 in mucosal crypt epithelia favor ASO as compared to NA (P < 0.001 = 3.4 × 10(-6) and 3.1 × 10(-5), respectively). Our findings suggest that appendiceal schistosomiasis was associated with increased proliferation and neuroendocrine differentiation of mucosal pluripotent crypt cells and that it may contribute to GCC, which is documented to originate from mucosal pluripotent crypt cells in mucosal crypt epithelia.

Cutaneous vasculitis in ulcerative colitis mimicking Henoch–Schönlein purpura

To the best of our knowledge, no cases of ulcerative colitis (UC) mimicking Henoch–Schönlein purpura (HSP) have been reported so far. During a 28-year period 5635 patients were followed up at our Pediatric Rheumatology Unit and 357 had HSP according to the European League Against Rheumatism, the Paediatric Rheumatology International Trials Organisation and the Paediatric Rheumatology European Society validated classification criteria. At the same period, 148 patients with IBD according to the European Society for Paediatric Gastroenterology, Hepatology and Nutrition criteria were followed up at the Pediatric Gastroenterology Unit in our University Hospital. Only two of them had vasculitis, as an extra intestinal manifestation of UC mimicking HSP, and fulfilled both disease criteria. A 2-year old girl had bloody diarrhoea, severe abdominal pain, arthritis in ankles, petechiae and palpable purpura not related to thrombocytopenia in lower limbs. A 5-year old boy had bloody diarrhoea, palpable purpura in buttocks, lower limbs, penis and scrotum associated with arthritis in knees, orchitis in right testicle and periarticular swelling in hands and feet. Their ileocolonoscopy showed diffuse mucosal erythema, oedema, friability and multiple irregular ulcers, and histopathological examination of colonic specimen revealed diffuse chronic mucosal inflammation, crypt distortion and crypt abscesses suggesting ulcerative colitis. There were no signs of intestinal vasculitis in both cases. In conclusion, this is the first study in a paediatric population that evidenced palpable purpura associated with UC mimicking HSP.

PDGF-α stimulates intestinal epithelial cell turnover after massive small bowel resection in a rat

Numerous cytokines have been shown to affect epithelial cell differentiation and proliferation through epithelial-mesenchymal interaction. Growing evidence suggests that platelet-derived growth factor (PDGF) signaling is an important mediator of these interactions. The purpose of this study was to evaluate the effect of PDGF-α on enterocyte turnover in a rat model of short bowel syndrome (SBS). Male rats were divided into four groups: Sham rats underwent bowel transection, Sham-PDGF-α rats underwent bowel transection and were treated with PDGF-α, SBS rats underwent a 75% bowel resection, and SBS-PDGF-α rats underwent bowel resection and were treated with PDGF-α. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at euthanasia. Illumina's Digital Gene Expression analysis was used to determine PDGF-related gene expression profiling. PDGF-α and PDGF-α receptor (PDGFR-α) expression was determined by real-time PCR. Western blotting was used to determine p-ERK, Akt1/2/3, bax, and bcl-2 protein levels. SBS rats demonstrated a significant increase in PDGF-α and PDGFR-α expression in jejunum and ileum compared with sham animals. SBS-PDGF-α rats demonstrated a significant increase in bowel and mucosal weight, villus height, and crypt depth in jejunum and ileum compared with SBS animals. PDGF-α receptor expression in crypts increased in SBS rats (vs. sham) and was accompanied by an increased cell proliferation following PDGF-α administration. A significant decrease in cell apoptosis in this group was correlated with lower bax protein levels. In conclusion, in a rat model of SBS, PDGF-α stimulates enterocyte turnover, which is correlated with upregulated PDGF-α receptor expression in the remaining small intestine.

Effect of Boswellia serrata on Antioxidant Status in an Experimental Model of Colitis Rats Induced by Acetic Acid

To evaluate the antioxidant effect of an extract of the plant Boswellia serrata in an experimental model of acute ulcerative colitis induced by administration of acetic acid (AA) in rats. The extract of B. serrata (34.2 mg/kg/day) was administered orally by gavage for 2 days before and after induction of colitis with AA diluted to 4 % and in a volume of 4 ml. The anal sphincter pressure in the groups treated with B. serrata showed a significant increase compared to the colitis group (P < 0.001). Histological analysis of treated animals showed less edema with preservation of mucosal crypts. Lipid peroxidation showed a significant decrease in the treated groups compared to the colitis group (P < 0.001). The superoxide dismutase (SOD) enzyme activity showed a significant reduction in the treated groups compared to the colitis group (P < 0.001), the glutathione peroxidase (GPx) significantly increased in the treated groups compared to colitis group (P < 0.05), and the same was the result for enzyme activity glutathione (GSH; P < 0.05). The extract of B. serrata has active antioxidant substances that exert protective effects in acute experimental colitis.

Intact function of Lgr5 receptor-expressing intestinal stem cells in the absence of Paneth cells

Lifelong self-renewal of the adult intestinal epithelium requires the activity of stem cells located in mucosal crypts. Lgr5 and Bmi1 are two molecular markers of crypt-cell populations that replenish all lineages over time and hence function as stem cells. Intestinal stem cells require Wnt signaling, but the understanding of their cellular niche is incomplete. Lgr5-expressing crypt base columnar cells (CBCs) reside deep in the crypt, mingled among mature Paneth cells that are well positioned for short-range signaling. Partial lineage ablation previously had implied that Paneth cells are nonessential constituents of the stem-cell niche, but recently their absence was reported to interfere with Lgr5(+) CBCs, resurrecting an appealing idea. However, previous mouse models failed to remove Paneth cells completely or permanently; defining the intestinal stem-cell niche requires clarity with respect to the Paneth cell role. We find that Lgr5(+) cells with stem-cell activity cluster in future crypts early in life, before Paneth cells develop. We also crossed conditional Atoh1(-/-) mice, which lack Paneth cells entirely, with Lgr5(GFP) mice to visualize Lgr5(+) CBCs and to track their stem-cell function. In the sustained absence of Paneth cells, Lgr5(+) CBCs occupied the full crypt base, proliferated briskly, and generated differentiated progeny over many months. Gene expression in fluorescence-sorted Lgr5(+) CBCs reflected intact Wnt signaling despite the loss of Paneth cells. Thus, Paneth cells are dispensable for survival, proliferation, and stem-cell activity of CBCs, and direct contact with Lgr5-nonexpressing cells is not essential for CBC function.

Exogenous GLP-2 and IGF-I induce a differential intestinal response in IGF binding protein-3 and -5 double knockout mice

Glucagon-like peptide-2 (GLP-2) action is dependent on intestinal expression of IGF-I, and IGF-I action is modulated by IGF binding proteins (IGFBP). Our objective was to evaluate whether the intestinal response to GLP-2 or IGF-I is dependent on expression of IGFBP-3 and -5. Male, adult mice in six treatment groups, three wild-type (WT) and three double IGFBP-3/-5 knockout (KO), received twice daily intraperitoneal injections of GLP-2 (0.5 μg/g body wt), IGF-I (4 μg/g body wt), or PBS (vehicle) for 7 days. IGFBP-3/-5 KO mice showed a phenotype of lower plasma IGF-I concentration, but greater body weight and relative mass of visceral organs, compared with WT mice (P < 0.001). WT mice showed jejunal growth with either IGF-I or GLP-2 treatment. In KO mice, IGF-I did not stimulate jejunal growth, crypt mitosis, sucrase activity, and IGF-I receptor (IGF-IR) expression, suggesting that the intestinotrophic actions of IGF-I are dependent on expression of IGFBP-3 and -5. In KO mice, GLP-2 induced significant increases in jejunal mucosal cellularity, crypt mitosis, villus height, and crypt depth that was associated with increased expression of the ErbB ligand epiregulin and decreased expression of IGF-I and IGF-IR. This suggests that in KO mice, GLP-2 action in jejunal mucosa is independent of the IGF-I system and linked with ErbB ligands. In summary, the intestinotrophic actions of IGF-I, but not GLP-2, in mucosa are dependent on IGFBP-3 and -5. These findings support the role of multiple downstream mediators for the mucosal growth induced by GLP-2.

A case of unexpected regeneration of small intestinal mucosal necrosis

If full-thickness mucosa, including the mucosal crypt, has been almost denuded, mucosa cannot regenerate as has been shown by animal models. The authors experienced an unusual mucosal regeneration exceed denuded bowel that occur in midgut volvulus of duration 2 days in a 6-day-old infant. Santulli's jejunostomy was performed using seriously denuded small bowel to prevent short bowel syndrome, despite the risks of leakage or stricture. Subsequently, stomal mucosa was fully regenerated when grossly identified 19 days after the second operation without any surgical complications.

Loss of Glucagon-Like Peptide-2–Induced Proliferation Following Intestinal Epithelial Insulin-Like Growth Factor-1–Receptor Deletion

Glucagon-like peptide-2 (GLP-2) is an intestinal hormone that promotes growth of the gastrointestinal tract. Although insulin-like growth factor (IGF)-1 and the IGF-1 receptor (IGF-1R) are required for GLP-2-induced proliferation of crypt cells, little is known about localization of the IGF-1R which mediates the intestinotropic actions of GLP-2. We examined intestinal growth and proliferative responses in mice with conditional deletion of IGF-1R from intestinal epithelial cells (IE-igf1rKO) after acute administration (30-90 min) of GLP-2, in response to 24-hour fasting and re-feeding (to induce GLP-2-dependent adaptation), and after chronic exposure (10 days) to GLP-2. IE-igf1rKO mice had normal small intestinal weight, morphometric parameters, proliferative indices, and distribution of differentiated epithelial cell lineages. Acute administration of GLP-2 increased nuclear translocation of β-catenin in non-Paneth crypt cells and stimulated the crypt-cell proliferative marker c-Myc in control but not IE-igf1rKO mice. Small intestinal weight, crypt depth, villus height, and crypt-cell proliferation were decreased in control and IE-igf1rKO mice after 24-hour fasting. Although re-feeding control mice restored all of these parameters, re-fed IE-igf1rKO mice had reductions in adaptive regrowth of the villi and crypt-cell proliferation. Control mice that were given chronic GLP-2 had increases in small intestinal weight, mucosal cross-sectional area, crypt depth, villus height, and crypt-cell proliferation. However, the GLP-2-induced increase in crypt-cell proliferation was not observed in IE-igf1rKO mice, and growth of the crypt-villus axis was reduced. The proliferative responses of the intestinal epithelium to exogenous GLP-2 administration and conditions of GLP-2-dependent adaptive re-growth require the intestinal epithelial IGF-1R.

Abstracts and Case Studies From the College of American Pathologists 2011 Annual Meeting (CAP '11)

Abstracts and Case Studies From the College of American Pathologists 2011 Annual Meeting (CAP '11)

Histomorphometrical evaluation of the gastrointestinal mucosa following chronic administration of Ghrelin in rat

Ghrelin, a peptide hormone, has several functions, of which the best known is its growth hormone (GH)-releasing effect in the pituitary. It also increases appetite and feeding behavior. Recent studies have implicated ghrelin in the regulation of gastrointestinal, cardiovascular, and immune function, and suggest a role for ghrelin in bone physiology. In this study, the effect of chronically administered ghrelin on the histomorphometrical properties of stomach and different parts of intestinal mucosa were evaluated in a rat model. Significant differences between control and ghrelin-treated groups were observed in gastrointestinal mucosa, stomach gland length, and duodenal mucosal thickness, villus length and crypt depth (P

Behcet disease and celiac disease: to screen or not?

Behcet’s disease (BD) is a chronic, relapsing, inflammatory disease characterized by recurrent oral aphthae and any of the several systemic manifestations including genital aphthae, ocular disease, skin lesions, gastrointestinal involvement, neurologic disease, vascular disease, or arthritis. BD is an autoimmune disorder and may be associated with other autoimmune diseases, but the underlying pathogenetic mechanism of the disease is not well understood [1]. Up to now, only a few cases have been described with BD and celiac disease (CD). Herein, we report a case of BD overlap with CD. A 17-year-old young was admitted to our clinic because of diarrhea, bloating, and abdominal distension. The patient’s medical history included BD. In addition, he had been taking colchicine for 2 years for BD. Microscopic examination of stool was normal. Serum biochemical parameters were within the normal range. Complete blood count revealed mild anemia with hb: 13.2 g/l and iron: 87(70–180) and total iron binding capacity: 417(227–428) and ferritine: 12 ng/ml (15–140). Because of iron deficiency, diarrhea and abdominal symptoms serum tissue transglutaminase (tTG) and gliadin antibodies were checked for celiac disease. Immunoglobulin A class tTG and IgG gliadin antibodies were found positive with normal serum immunoglobulin levels. In order to confirm the diagnosis of CD, an upper gastrointestinal system endoscopy with duodenal biopsy was performed. It showed scalloping of folds, and histopathological examination showed subtotal villous atrophy (Marsh 3a). Gluten-free diet was instituted, and all the symptoms significantly decreased in follow-up. Celiac disease can be defined as a small-bowel disorder characterized by mucosal inflammation, villous atrophy, and crypt hyperplasia, which occur upon exposure to dietary gluten and which demonstrate improvement after withdrawal of gluten from the diet [2]. Patients affected by CD have greater risk of developing autoimmune diseases, among them rheumatic diseases. BD and CD share many clinical presentations, such as recurrent aphthous stomatitis, as well as gastrointestinal, musculoskeletal, and neurologic involvements. There are only three studies concerning the association of BD and CD in the literature [3–5]. In these reports, patients with BD were screened for CD and only two of them were diagnosed with histologically proven CD. In addition, two other cases with CD and BD have been reported in the literature. Most of these cases showed alarm symptoms for early further investigations. In our case, patient referred to our clinic because of diarrhea and bloating. Colchicine is commonly used in the treatment of BD and has many gastrointestinal side effects including abdominal pain, cramping, nausea, vomiting, and diarrhea. Differential diagnosis of CD and colchicine side effects may be difficult because of similar symptoms and may result interruption of treatment. In conclusion, despite the rarity of this combination, both disease have immunogenic mechanism and share many clinical manifestations. It is still unclear whether all patients with BD should be screened for CD or not, and in addition, colchicine treatment may cause differential diagnosis more difficult. If diarrhea and iron deficiency are seen in a patient with BD, the serologic tests with smallbowel biopsy should be performed to exclude CD. B. Ergul E. Kocak (&) S. Koklu Department of Gastroenterology, Ankara Education and Research Hospital, Keklikpinari mahallesi, 240 sokak, Duru apartmani, 8/6, Dikmen, Cankaya, Ankara, Turkey e-mail: kocak67@hotmail.com