Morphological development of the small intestinal mucosa involves the stepwise remodeling of a smooth-surfaced endodermal tube to form finger-like luminal projections (villi) and flask-shaped invaginations (crypts). These remodeling processes are orchestrated by instructive signals that pass bidirectionally between the epithelium and underlying mesenchyme. Sonic (Shh) and Indian (Ihh) hedgehog ...

Injury, inflammation, or resection of the small intestine results in severe compromise of intestinal function. Nevertheless, therapeutic strategies for enhancing growth and repair of the intestinal mucosal epithelium are currently not available. We demonstrate that nude mice bearing subcutaneous proglucagon-producing tumors exhibit marked proliferation of the small intestinal epithelium. The fa...

The use of engineered nanoparticles in food and pharmaceuticals is expected to increase, but the impact of chronic oral exposure to nanoparticles on human health remains unknown. Here, we show that chronic and acute oral exposure to polystyrene nanoparticles can influence iron uptake and iron transport in an in vitro model of the intestinal epithelium and an in vivo chicken intestinal loop mode...

Recent efforts examining forces during morphogenesis suggest a role for mechanical crosstalk between epithelium and mesenchyme in tissue patterning. Reporting in Science, Shyer et al. (2013) show that differences between the mechanical properties of the developing intestinal epithelium and surrounding smooth muscle fold the epithelium into villi via mucosal buckling.

Simultaneous measurements of all major electrolytes including HCO3(-) and H+ as well as water demonstrated that fluids absorbed by the anterior intestine of the marine gulf toadfish under in vivo-like conditions on an overall net basis are hypertonic at 380 mOsm and acidic ([H+] = 27 mM). This unusual composition of fluids absorbed across the intestinal epithelium is due to the unusual intestin...

Pharmacologic blockade of EGFR or the closely related receptor ERBB2 has modest efficacy against colorectal cancers in the clinic. Although the upregulation of ERBB3, a pseudo-kinase member of the EGFR/ERBB family, is known to contribute to EGFR inhibitor resistance in other cancers, its functions in normal and malignant intestinal epithelium have not been defined. We have shown here that the i...

The epithelium of the gastrointestinal tract is constantly renewed as it turns over. This process is triggered by the proliferation of intestinal stem cells (ISCs) and progeny that progressively migrate and differentiate toward the tip of the villi. These processes, essential for gastrointestinal homeostasis, have been extensively studied using multiple approaches. Ex vivo technologies, especia...

The intestinal epithelium is sensitive to radiation injury. Damage to the intestinal epithelium is dose limiting in radiation therapy of abdominal cancers. There is a need for agents that can be given before radiation therapy to protect the intestinal epithelium. C57BL6 mice were subjected to 12 Gy of total body radiation. Some mice received intraperitoneal hyaluronic acid (HA) before radiation...

Nuclear receptor PPARγ affects lipid metabolism in several tissues, but its role in intestinal lipid metabolism has not been explored. As alterations have been observed in the plasma lipid profile of ad libitum fed intestinal epithelium-specific PPARγ knockout mice (iePPARγKO), we submitted these mice to lipid gavage challenges. Within hours after gavage with long chain unsaturated fatty acid (...

The immune system of the gastrointestinal (GI) tract manages the significant task of recognizing and eliminating pathogens while maintaining tolerance of commensal bacteria. Dysregulation of this delicate balance can be detrimental, resulting in severe inflammation, intestinal injury, and cancer. Therefore, mechanisms to relay important signals regulating cell growth and immune reactivity must ...