title: [Overexpression of NHE1 suppresses ABCA1 protein expression via increasing calpain activity in RAW264.7 cells].
abstract: Objective To investigate the effect of over-expressed Na+/H+exchanger 1 (NHE1) on the protein expression of adenosine three phosphate binding cassette transporter A1 (ABCA1) in RAW264.7 cells. Methods RAW264.7 cells were infected with the adenoviral vector encoding NHE1-EGFP (AdNHE1). The infected RAW264.7 cells were subjected to Western blot analysis for NHE1-EGFP fusion protein. The subcellular localization of NHE1-EGFP fusion protein was observed by confocal laser scanning microscopy. NHE1 activity was measured by the method of pH recovery in response to an acute acid pulse. Furthermore, Western blotting was performed to determine ABCA1 protein levels and calpain activity in NHE1-overexpressing RAW264.7 cells. The effect of calpain inhibitor N-acetyl-L-leucyl-L-leucyl-L-norleucinal (ALLN) on ABCA1 protein levels in the presence of TO-901317 was examined by Western blotting. Results NHE1-EGFP fusion protein was highly expressed and localized in cytoplasm and cell membrane of RAW264.7 cells infected with AdNHE1. NHE1-EGFP fusion protein reduced ABCA1 protein expression and increased calpain activity. The calpain inhibitor ALLN blocked the decrease of ABCA1 protein expression. Conclusion Overexpressed NHE1 suppresses the expression of ABCA1 protein via increasing the calpain activity in RAW264.7 cells.
authors.affiliation: Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China. *Corresponding author, E-mail:moxiangang123@126.com.
authors.forename: Xiangang
authors.initials: X
authors.lastname: Mo
authors.affiliation: Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Guo
authors.affiliation: Guizhou Key Laboratory of Medical Molecular Biology, Guiyang 550004, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hong
authors.affiliation: Department of Immunology, Guizhou Medical University, Guiyang 550004, China.
authors.forename: Shiqi
authors.initials: S
authors.lastname: Long
authors.affiliation: Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xiang
authors.affiliation: Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
mesh_terms: D064286:ATP Binding Cassette Transporter 1 / Q000378:metabolism*; D000818:Animals; D002154:Calpain / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000378:metabolism*; D002460:Cell Line; D051379:Mice; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism*
chemical_list: D064286:ATP Binding Cassette Transporter 1; D002154:Calpain; D027682:Cation Transport Proteins; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers; C577833:Abca1 protein, mouse; C490997:Slc9a1 protein, mouse