BACKGROUND: Intestinal alkaline phosphatase (IAP) plays a pivotal role in maintaining gut health and well-being. Oral supplementation with IAP in mice improves gut barrier function and prevents luminal proinflammatory factors from gaining access to the circulation. In this study, we sought to explore the relationship between IAP and tight junction protein (TJP) expression and function. STUDY DESIGN: The effect of IAP deletion on TJP levels was studied in mouse embryonic fibroblasts (MEFs) generated from IAP-knockout and wild type mice. Regulation of TJPs by IAP was assayed in the human colon cancer Caco-2 and T84 cells by overexpressing the human IAP gene. Tight junction protein levels and localization were measured by using RT q-PCR and antibodies targeting the specific TJPs. Finally, the effect of IAP on inflammation-induced intestinal permeability was measured by in vitro trans-well epithelial electrical resistance (TEER). RESULTS: Intestinal alkaline phosphatase gene deletion in MEFs resulted in significantly lower levels of ZO-1, ZO-2, and Occludin compared with levels in wild-type control cells; IAP overexpression in Caco-2 and T84 cells resulted in approximate 2-fold increases in the mRNA levels of ZO-1 and ZO-2. The IAP treatment ameliorated lipopolysaccharide-induced increased permeability in the Caco-2 trans-well system. Furthermore, IAP treatment preserved the localization of the ZO-1 and Occludin proteins during inflammation and was also associated with improved epithelial barrier function. CONCLUSIONS: Intestinal alkaline phosphatase is a major regulator of gut mucosal permeability and appears to work at least partly through improving TJP levels and localization. These data provide a strong foundation to develop IAP as a novel therapy to maintain gut barrier function.
BACKGROUND:Intestinal alkaline phosphatase (IAP) plays a pivotal role in maintaining gut health and well-being. Oral supplementation with IAP in mice improves gut barrier function and prevents luminal proinflammatory factors from gaining access to the circulation. In this study, we sought to explore the relationship between IAP and tight junction protein (TJP) expression and function. STUDY DESIGN: The effect of IAP deletion on TJP levels was studied in mouse embryonic fibroblasts (MEFs) generated from IAP-knockout and wild type mice. Regulation of TJPs by IAP was assayed in the humancolon cancerCaco-2 and T84 cells by overexpressing the humanIAP gene. Tight junction protein levels and localization were measured by using RT q-PCR and antibodies targeting the specific TJPs. Finally, the effect of IAP on inflammation-induced intestinal permeability was measured by in vitro trans-well epithelial electrical resistance (TEER). RESULTS:Intestinal alkaline phosphatase gene deletion in MEFs resulted in significantly lower levels of ZO-1, ZO-2, and Occludin compared with levels in wild-type control cells; IAP overexpression in Caco-2 and T84 cells resulted in approximate 2-fold increases in the mRNA levels of ZO-1 and ZO-2. The IAP treatment ameliorated lipopolysaccharide-induced increased permeability in the Caco-2 trans-well system. Furthermore, IAP treatment preserved the localization of the ZO-1 and Occludin proteins during inflammation and was also associated with improved epithelial barrier function. CONCLUSIONS:Intestinal alkaline phosphatase is a major regulator of gut mucosal permeability and appears to work at least partly through improving TJP levels and localization. These data provide a strong foundation to develop IAP as a novel therapy to maintain gut barrier function.
Authors: Madhu S Malo; Omeed Moaven; Nur Muhammad; Brishti Biswas; Sayeda N Alam; Konstantinos P Economopoulos; Sarah Shireen Gul; Sulaiman R Hamarneh; Nondita S Malo; Abeba Teshager; Mussa M Rafat Mohamed; Qingsong Tao; Sonoko Narisawa; José Luis Millán; Elizabeth L Hohmann; H Shaw Warren; Simon C Robson; Richard A Hodin Journal: Am J Physiol Gastrointest Liver Physiol Date: 2014-04-10 Impact factor: 4.052
Authors: Stephan C Bischoff; Giovanni Barbara; Wim Buurman; Theo Ockhuizen; Jörg-Dieter Schulzke; Matteo Serino; Herbert Tilg; Alastair Watson; Jerry M Wells Journal: BMC Gastroenterol Date: 2014-11-18 Impact factor: 3.067
Authors: Antonis Kourtidis; Siu P Ngok; Pamela Pulimeno; Ryan W Feathers; Lomeli R Carpio; Tiffany R Baker; Jennifer M Carr; Irene K Yan; Sahra Borges; Edith A Perez; Peter Storz; John A Copland; Tushar Patel; E Aubrey Thompson; Sandra Citi; Panos Z Anastasiadis Journal: Nat Cell Biol Date: 2015-08-24 Impact factor: 28.824
Authors: Florian Kühn; Ruifeng Duan; Matthias Ilmer; Ulrich Wirth; Fatemeh Adiliaghdam; Tobias S Schiergens; Joachim Andrassy; Alexandr V Bazhin; Jens Werner Journal: Visc Med Date: 2021-04-29
Authors: Florian Kühn; Fatemeh Adiliaghdam; Paul M Cavallaro; Sulaiman R Hamarneh; Amy Tsurumi; Raza S Hoda; Alexander R Munoz; Yashoda Dhole; Juan M Ramirez; Enyu Liu; Robin Vasan; Yang Liu; Ehsan Samarbafzadeh; Rocio A Nunez; Matthew Z Farber; Vanita Chopra; Madhu S Malo; Laurence G Rahme; Richard A Hodin Journal: JCI Insight Date: 2020-03-26