NHE1 activity contributes to migration and is necessary for proliferation of human gastric myofibroblasts.

Abstract

Myofibroblasts play central roles in wound healing, deposition of the extracellular matrix and epithelial function. Their functions depend on migration and proliferation within the subepithelial matrix, which results in accelerated cellular metabolism. Upregulated metabolic pathways generate protons which need to be excreted to maintain intracellular pH (pH(i)). We isolated human gastric myofibroblasts (HGMs) from surgical specimens of five patients. Then we characterized, for the first time, the expression and functional activities of the Na(+)/H(+) exchanger (NHE) isoforms 1, 2 and 3, and the functional activities of the Na(+)/HCO(3)(-) cotransporter (NBC) and the anion exchanger (AE) in cultured HGMs using microfluorimetry, immunocytochemistry, reverse transcription polymerase chain reaction and immunoblot analysis. We showed that NHE1-3, NBC and AE activities are present in HGMs and that NHE1 is the most active of the NHEs. In scratch wound assays we also demonstrated (using the selective NHE inhibitor HOE-642) that carbachol and insulin like growth factor II (IGF-II) partly stimulate migration of HGMs in a NHE1-dependent manner. EdU incorporation assays revealed that IGF-II induces proliferation of HGMs which is inhibited by HOE-642. The results indicate that NHE1 is necessary for IGF-II-induced proliferation response of HGMs. Overall, we have characterized the pH(i) regulatory mechanisms of HGMs. In addition, we demonstrated that NHE1 activity contributes to both IGF-II- and carbachol-stimulated migration and that it is obligatory for IGF-II-induced proliferation of HGMs.

• Authors: Mátyás Czepán, Zoltán Rakonczay Jr, Andrea Varró, Islay Steele, Rod Dimaline, Nantaporn Lertkowit, János Lonovics, Andrea Schnúr, György Biczó, Andrea Geisz, György Lázár, Zsolt Simonka, Viktória Venglovecz, Tibor Wittmann, Péter Hegyi
• Journal: Pflugers Archiv : European journal of physiology (Pflugers Arch) Vol. 463 Issue 3 Pg. 459-75 (Mar 2012) ISSN: 1432-2013 [Electronic] Germany
• PMID: 22138972 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antiporters
• Cation Transport Proteins
• Guanidines
• SLC9A1 protein, human
• SLC9A2 protein, human
• Sodium-Bicarbonate Symporters
• Sodium-Hydrogen Exchanger 1
• Sodium-Hydrogen Exchanger 3
• Sodium-Hydrogen Exchangers
• Sulfones
• Insulin-Like Growth Factor II
• cariporide
• Carbachol

Topics

• Adult
• Aged
• Antiporters (biosynthesis)
• Carbachol (pharmacology)
• Cation Transport Proteins (antagonists & inhibitors, physiology)
• Cell Movement
• Cell Proliferation
• Female
• Guanidines (pharmacology)
• Humans
• Hydrogen-Ion Concentration
• Insulin-Like Growth Factor II (physiology)
• Male
• Myofibroblasts (physiology)
• Sodium-Bicarbonate Symporters (physiology)
• Sodium-Hydrogen Exchanger 1
• Sodium-Hydrogen Exchanger 3
• Sodium-Hydrogen Exchangers (antagonists & inhibitors, biosynthesis, physiology)
• Stomach (cytology)
• Sulfones (pharmacology)