@article{CardaniSardiLaFerlaetal.2014, author = {Cardani, Diego and Sardi, Claudia and La Ferla, Barbara and D'Orazio, Guiseppe and Sommariva, Michele and Marcucci, Fabrizio and Olivero, Daniela and Tagliabue, Elda and Koepsell, Hermann and Nicotra, Francesco and Balsari, Andrea and Rumio, Christiano}, title = {Sodium glucose cotransporter 1 ligand BLF501 as a novel tool for management of gastrointestinal mucositis}, series = {Molecular Cancer}, volume = {13}, journal = {Molecular Cancer}, number = {23}, issn = {1476-4598}, doi = {10.1186/1476-4598-13-23}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117352}, year = {2014}, abstract = {Background: Recent studies demonstrated that engagement of sodium glucose transporter 1 (SGLT-1) by orally administered D-glucose protects the intestinal mucosa from lipopolysaccharide (LPS)-induced injury. We tested whether SGLT-1 engagement might protect the intestinal mucosa from doxorubicin (DXR)- and 5-fluorouracil (5-FU)-induced injury in animal models mimicking acute or chronic mucositis. Methods: Mice were treated intraperitoneally with DXR, alone or in combination with 5-FU, and orally with BLF501, a glucose-derived synthetic compound with high affinity for SGLT-1. Intestinal mucosal epithelium integrity was assessed by histological analysis, cellular proliferation assays, real-time PCR gene expression assays and Western blot assays. Student's t-test (paired two-tailed) and X-2 analyses were used for comparisons between groups. Differences were considered significant at p < 0.05. Results: BLF501 administration in mice treated with DXR and/or 5-FU decreased the injuries to the mucosa in terms of epithelial integrity and cellular proliferative ability. Co-treatment with BLF501 led to a normal expression and distribution of both zonula occludens-1 (ZO-1) and beta-catenin, which were underexpressed after treatment with either chemotherapeutic agent alone. BLF501 administration also restored normal expression of caspase-3 and ezrin/radixin/moesin (ERM), which were overexpressed after treatment with DXR and 5-FU. In SGLT1-/- mice, BLF501 had no detectable effects. BLF501 administration in wild-type mice with growing A431 tumors did not modify antitumor activity of DXR. Conclusions: BLF501-induced protection of the intestinal mucosa is a promising novel therapeutic approach to reducing the severity of chemotherapy-induced mucositis.}, language = {en} } @article{RoederGeillingerZieteketal.2014, author = {R{\"o}der, Pia V. and Geillinger, Kerstin E. and Zietek, Tamara S. and Thorens, Bernard and Koepsell, Hermann and Daniel, Hannelore}, title = {The Role of SGLT1 and GLUT2 in Intestinal Glucose Transport and Sensing}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {2}, doi = {10.1371/journal.pone.0089977}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117262}, pages = {e89977}, year = {2014}, abstract = {Intestinal glucose absorption is mediated by SGLT1 whereas GLUT2 is considered to provide basolateral exit. Recently, it was proposed that GLUT2 can be recruited into the apical membrane after a high luminal glucose bolus allowing bulk absorption of glucose by facilitated diffusion. Moreover, SGLT1 and GLUT2 are suggested to play an important role in intestinal glucose sensing and incretin secretion. In mice that lack either SGLT1 or GLUT2 we re-assessed the role of these transporters in intestinal glucose uptake after radiotracer glucose gavage and performed Western blot analysis for transporter abundance in apical membrane fractions in a comparative approach. Moreover, we examined the contribution of these transporters to glucose-induced changes in plasma GIP, GLP-1 and insulin levels. In mice lacking SGLT1, tissue retention of tracer glucose was drastically reduced throughout the entire small intestine whereas GLUT2-deficient animals exhibited higher tracer contents in tissue samples than wild type animals. Deletion of SGLT1 resulted also in reduced blood glucose elevations and abolished GIP and GLP-1 secretion in response to glucose. In mice lacking GLUT2, glucose-induced insulin but not incretin secretion was impaired. Western blot analysis revealed unchanged protein levels of SGLT1 after glucose gavage. GLUT2 detected in apical membrane fractions mainly resulted from contamination with basolateral membranes but did not change in density after glucose administration. SGLT1 is unequivocally the prime intestinal glucose transporter even at high luminal glucose concentrations. Moreover, SGLT1 mediates glucose-induced incretin secretion. Our studies do not provide evidence for GLUT2 playing any role in either apical glucose influx or incretin secretion.}, language = {en} }