title: NHE-1 is the sodium-hydrogen exchanger isoform present in erythroid cells.
abstract: Erythrocyte sodium hydrogen exchanger (NHE) represents one of a limited number of sodium entry pathway in erythrocytes. At least five NHE isoforms have been identified, differing in tissue specificity, regulatory characteristics, and pharmacological sensitivities. Although physiological characteristics of erythrocyte NHE suggest that the widely expressed NHE-1 isoform may be present, evidence is not conclusive and does not exclude the existence of other isoforms. In this study, Northern blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses were used to test for five NHE isoforms in erythroid cells. Blood from patients with sickle cell disease was depleted of white blood cells (WBC) by passage through leukocyte filters and cellulose column. RT-PCR performed on WBC depleted reticulocyte RNA using a NHE-1 primer set yielded product a of expected size, the sequence of which was identical to the published human NHE-1 sequence. Northern blot analysis of the reticulocyte RNA using a 1.6 kb probe revealed a message of approximately 5.0 kb in size. RT-PCR analysis of rat kidney RNA using primers specific for NHE isoforms -2, -3, -4 and rat brain RNA using primer specific for NHE-5 isoform yielded products of expected size, whereas WBC depleted RNA under identical conditions yielded no products. These results identify the erythroid isoform of the sodium hydrogen exchanger as NHE-1.
authors.affiliation: Division of Hematology/Oncology, Department of Pediatrics, Cincinnati Comprehensive Sickle Cell Center, OH 45229, USA.
authors.forename: R
authors.initials: R
authors.lastname: Sarangarajan
authors.forename: N
authors.initials: N
authors.lastname: Dhabia
authors.forename: M
authors.initials: M
authors.lastname: Soleimani
authors.forename: M
authors.initials: M
authors.lastname: Soliemani
authors.forename: N
authors.initials: N
authors.lastname: Baird
authors.forename: C
authors.initials: C
authors.lastname: Joiner
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004912:Erythrocytes / Q000378:metabolism*; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D006801:Humans; D066298:In Vitro Techniques; D007962:Leukocytes / Q000378:metabolism; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017923:Sodium-Hydrogen Exchangers / Q000097:blood* / Q000235:genetics
chemical_list: D017931:DNA Primers; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen; D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers; C069139:growth factor-activatable Na-H exchanger NHE-1