title: Na+/H+exchanger NHE1 and NHE2 have opposite effects on migration velocity in rat gastric surface cells.
abstract: Following superficial injury, neighbouring gastric epithelial cells close the wound by rapid cell migration, a process called epithelial restitution. Na+/H+exchange (NHE) inhibitors interfere with restitution, but the role of the different NHE isoforms expressed in gastric pit cells has remained elusive. The role of the basolaterally expressed NHE1 (Slc9a1) and the presumably apically expressed NHE2 (Slc9a2) in epithelial restitution was investigated in the nontransformed rat gastric surface cell line RGM1. Migration velocity was assessed by loading the cells with the fluorescent dye DiR and following closure of an experimental wound over time. Since RGM1 cells expressed very low NHE2 mRNA and have low transport activity, NHE2 was introduced by lentiviral gene transfer. In medium with pH 7.4, RGM1 cells displayed slow wound healing even in the absence of growth factors and independently of NHE activity. Growth factors accelerated wound healing in a partly NHE1-dependent fashion. Preincubation with acidic pH 7.1 stimulated restitution in a NHE1-dependent fashion. When pH 7.1 was maintained during the restitution period, migratory speed was reduced to ∼10% of the speed at pH 7,4, and the residual restitution was further inhibited by NHE1 inhibition. Lentiviral NHE2 expression increased the steady-state pHiand reduced the restitution velocity after low pH preincubation, which was reversible by pharmacological NHE2 inhibition. The results demonstrate that in RGM1 cells, migratory velocity is increased by NHE1 activation, while NHE2 activity inhibit this process. A differential activation of NHE1 and NHE2 may therefore, play a role in the initiation and completion of the epithelial restitution process.
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Paehler Vor der Nolte
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Giriprakash
authors.initials: G
authors.lastname: Chodisetti
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Zhenglin
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Busch
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Riederer
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Min
authors.initials: M
authors.lastname: Luo
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Departments of Biochemistry, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Manoj B
authors.initials: MB
authors.lastname: Menon
authors.affiliation: Departments of Hematology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Departments of Hematology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Renata
authors.initials: R
authors.lastname: Stripecke
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Katerina
authors.initials: K
authors.lastname: Nikolovska
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Sunil
authors.initials: S
authors.lastname: Yeruva
authors.affiliation: Departments of Gastroenterology, Hemostatsis, Oncology and Stem Cell Transplantation, Medical School of Hannover, Germany.
authors.forename: Ursula
authors.identifier: http://orcid.org/0000-0002-9600-2769
authors.initials: U
authors.lastname: Seidler
mesh_terms: D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D005753:Gastric Mucosa / Q000166:cytology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016086:Lentivirus / Q000378:metabolism; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D014945:Wound Healing
chemical_list: D012333:RNA, Messenger; C452850:Slc9a1 protein, rat; C513110:Slc9a2 protein, rat; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers; D049452:Green Fluorescent Proteins
keywords: Slc9a1; Slc9a2; cell migration; intracellular pH; mucosal protection; sodium hydrogen exchanger