Izumi Kaji1, Joseph T Roland2, Masahiko Watanabe3, Amy C Engevik2, Anna E Goldstein2, Craig A Hodges4, James R Goldenring5. 1. Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee. Electronic address: izumi.kaji@vumc.org. 2. Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee. 3. Hokkaido University Graduate School of Medicine, Sapporo, Japan. 4. Cystic Fibrosis Mouse Models Resource Center, Case Western Reserve University, Cleveland, OH. 5. Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee; Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee; Nashville Veterans Affairs Medical Center, Nashville, Tennessee.
Abstract
BACKGROUND & AIM: Myosin VB (MYO5B) is an essential trafficking protein for membrane recycling in gastrointestinal epithelial cells. The inactivating mutations of MYO5B cause the congenital diarrheal disease, microvillus inclusion disease (MVID). MYO5B deficiency in mice causes mislocalization of SGLT1 and NHE3, but retained apical function of CFTR, resulting in malabsorption and secretory diarrhea. Activation of lysophosphatidic acid (LPA) receptors can improve diarrhea, but the effect of LPA on MVID symptoms is unclear. We investigated whether LPA administration can reduce the epithelial deficits in MYO5B-knockout mice. METHODS: Studies were conducted with tamoxifen-induced, intestine-specific knockout of MYO5B (VilCreERT2;Myo5bflox/flox) and littermate controls. Mice were given LPA, an LPAR2 agonist (GRI977143), or vehicle for 4 days after a single injection of tamoxifen. Apical SGLT1 and CFTR activities were measured in Üssing chambers. Intestinal tissues were collected, and localization of membrane transporters was evaluated by immunofluorescence analysis in tissue sections and enteroids. RNA sequencing and enrichment analysis were performed with isolated jejunal epithelial cells. RESULTS: Daily administration of LPA reduced villus blunting, frequency of multivesicular bodies, and levels of cathepsins in intestinal tissues of MYO5B-knockout mice compared with vehicle administration. LPA partially restored the brush border height and the localization of SGLT1 and NHE3 in small intestine of MYO5B-knockout mice and enteroids. The SGLT1-dependent short-circuit current was increased and abnormal CFTR activities were decreased in jejunum from MYO5B-knockout mice given LPA compared with vehicle. CONCLUSIONS: LPA may regulate a MYO5B-independent trafficking mechanism and brush border maturation, and therefore be developed for treatment of MVID.
BACKGROUND & AIM: Myosin VB (MYO5B) is an essential trafficking protein for membrane recycling in gastrointestinal epithelial cells. The inactivating mutations of MYO5B cause the congenital diarrheal disease, microvillus inclusion disease (MVID). MYO5Bdeficiency in mice causes mislocalization of SGLT1 and NHE3, but retained apical function of CFTR, resulting in malabsorption and secretory diarrhea. Activation of lysophosphatidic acid (LPA) receptors can improve diarrhea, but the effect of LPA on MVID symptoms is unclear. We investigated whether LPA administration can reduce the epithelial deficits in MYO5B-knockout mice. METHODS: Studies were conducted with tamoxifen-induced, intestine-specific knockout of MYO5B (VilCreERT2;Myo5bflox/flox) and littermate controls. Mice were given LPA, an LPAR2 agonist (GRI977143), or vehicle for 4 days after a single injection of tamoxifen. Apical SGLT1 and CFTR activities were measured in Üssing chambers. Intestinal tissues were collected, and localization of membrane transporters was evaluated by immunofluorescence analysis in tissue sections and enteroids. RNA sequencing and enrichment analysis were performed with isolated jejunal epithelial cells. RESULTS: Daily administration of LPA reduced villus blunting, frequency of multivesicular bodies, and levels of cathepsins in intestinal tissues of MYO5B-knockout mice compared with vehicle administration. LPA partially restored the brush border height and the localization of SGLT1 and NHE3 in small intestine of MYO5B-knockout mice and enteroids. The SGLT1-dependent short-circuit current was increased and abnormal CFTR activities were decreased in jejunum from MYO5B-knockout mice given LPA compared with vehicle. CONCLUSIONS:LPA may regulate a MYO5B-independent trafficking mechanism and brush border maturation, and therefore be developed for treatment of MVID.
Authors: Sudiksha Rathan-Kumar; Joseph T Roland; Michael Momoh; Anna Goldstein; Lynne A Lapierre; Elizabeth Manning; Louise Mitchell; Jim Norman; Izumi Kaji; James R Goldenring Journal: Am J Physiol Gastrointest Liver Physiol Date: 2022-07-12 Impact factor: 4.871
Authors: Michael W Hess; Iris M Krainer; Przemyslaw A Filipek; Barbara Witting; Karin Gutleben; Ilja Vietor; Heinz Zoller; Denise Aldrian; Ekkehard Sturm; James R Goldenring; Andreas R Janecke; Thomas Müller; Lukas A Huber; Georg F Vogel Journal: J Clin Med Date: 2021-04-28 Impact factor: 4.964
Authors: Izumi Kaji; Joseph T Roland; Sudiksha Rathan-Kumar; Amy C Engevik; Andreanna Burman; Anna E Goldstein; Masahiko Watanabe; James R Goldenring Journal: JCI Insight Date: 2021-08-23