title: K-Cl cotransporter gene expression during human and murine erythroid differentiation.
abstract: The K-Cl cotransporter (KCC) regulates red blood cell (RBC) volume, especially in reticulocytes. Western blot analysis of RBC membranes revealed KCC1, KCC3, and KCC4 proteins in mouse and human cells, with higher levels in reticulocytes. KCC content was higher in sickle versus normal RBC, but the correlation with reticulocyte count was poor, with inter-individual variability in KCC isoform ratios. Messenger RNA for each isoform was measured by real time RT-quantitative PCR. In human reticulocytes, KCC3a mRNA levels were consistently the highest, 1-7-fold higher than KCC4, the second most abundant species. Message levels for KCC1 and KCC3b were low. The ratios of KCC RNA levels varied among individuals but were similar in sickle and normal RBC. During in vivo maturation of human erythroblasts, KCC3a RNA was expressed consistently, whereas KCC1 and KCC3b levels declined, and KCC4 message first increased and then decreased. In mouse erythroblasts, a similar pattern for KCC3 and KCC1 expression during in vivo differentiation was observed, with low KCC4 RNA throughout despite the presence of KCC4 protein in mature RBC. During differentiation of mouse erythroleukemia cells, protein levels of KCCs paralleled increasing mRNA levels. Functional properties of KCCs expressed in HEK293 cells were similar to each other and to those in human RBC. However, the anion dependence of KCC in RBC resembled most closely that of KCC3. The results suggest that KCC3 is the dominant isoform in erythrocytes, with variable expression of KCC1 and KCC4 among individuals that could result in modulation of KCC activity.
authors: Molecular and Cell Therapy Program, Division of Experimental Hematology, Cincinnati, Ohio 45229; the Departments of Pediatrics, Cincinnati, Ohio 45267. Electronic address: dao.pan@cchmc.org.
authors: Dao
authors: D
authors: Pan
authors: the Departments of Pediatrics, Cincinnati, Ohio 45267; Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229.
authors: Theodosia A
authors: TA
authors: Kalfa
authors: Molecular and Cell Therapy Program, Division of Experimental Hematology, Cincinnati, Ohio 45229.
authors: Daren
authors: D
authors: Wang
authors: Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229.
authors: Mary
authors: M
authors: Risinger
authors: Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229.
authors: Scott
authors: S
authors: Crable
authors: Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229.
authors: Anna
authors: A
authors: Ottlinger
authors: the Departments of Pediatrics, Cincinnati, Ohio 45267; Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229.
authors: Sharat
authors: S
authors: Chandra
authors: Renal Division, Brigham and Women's Hospital, Veterans Affairs Boston Healthcare System, Harvard Medical School, Boston, Massachusetts 02115.
authors: David B
authors: DB
authors: Mount
authors: Department of Clinical Chemistry, University Hospital of the Friedrich-Schiller-University, D-07747 Jena, Germany.
authors: Christian A
authors: CA
authors: Hübner
authors: Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229; Internal Medicine, University of Cincinnati School of Medicine, Cincinnati, Ohio 45267.
authors: Robert S
authors: RS
authors: Franco
authors: the Departments of Pediatrics, Cincinnati, Ohio 45267; Division of Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229. Electronic address: clinton.joiner@cchmc.org.
authors: Clinton H
authors: CH
authors: Joiner
mesh_terms: D000755:Anemia, Sickle Cell / Q000378:metabolism; D000818:Animals; D000838:Anions; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002712:Chlorides / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D020869:Gene Expression Profiling; D006801:Humans; D051379:Mice; D012156:Reticulocytes / Q000166:cytology; D027981:Symporters / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D000096922:K Cl- Cotransporters
chemical_list: D000838:Anions; D002712:Chlorides; D027981:Symporters; D000096922:K Cl- Cotransporters; C119650:SLC12A6 protein, human; C119651:SLC12A7 protein, human; C492280:Slc12a6 protein, mouse; C492282:Slc12a7 protein, mouse