HOME HELP FEEDBACK TABLE OF CONTENTS ARCHIVE SUBSCRIPTIONS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by De Franceschi, L. Articles by Iolascon, A. Search for Related Content PubMed PubMed Citation Articles by De Franceschi, L. Articles by Iolascon, A.

K-CL co-transport plays an important role in normal and ß thalassemic erythropoiesis

From the Department of Clinical and Experimental Medicine, Section of Internal Medicine, University of Verona, Italy (LDF, AS, CP); Department of Internal Medicine, University of Milano, Fondazione Policlinico Mangiagalli, Regina Elena, IRCCS, Milano; Italy (LR, MDC); Department of Biochemistry and Medical Biotechnology, University Federico II, CEINGE Napoli, Italy (FC, VS, AI); Molecular and Vascular Medicine and Renal Units, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA (SLA)

Correspondence: Maria Domenica Cappellini, MD, Department of Internal Medicine, University of Milano, IRCCS, Via F. Sforza, 35, 20122 Milano, Italy. E-mail: maria.cappellini{at}unimi.it

Background and Objectives: Cell volume changes are hallmarks of both cell maturation and apoptosis, and are paralleled by modulation of membrane ion transport pathways. We evaluated the possible role of K-Cl co-transport (KCC) in both normal and ß-thalassemic erythropoiesis in vitro.

Design and Methods: We studied the effects of the KCC inhibitor, DIOA, on cell proliferation and differentiation, on expression of KCC mRNA and polypeptides, and on expression of cell cycle and apoptosis genes in in vitro liquid-cultures of CD34⁺ cells from normal and ß-thalassemic subjects.

Results: ß-thalassemic erythroid precursors showed increased abundance of KCC1-3 mRNA and of KCC polypeptides in late erythropoiesis. DIOA markedly modified the composition of normal erythroid precursors, promoting differentiation and arrest at the polychromatic erythroblast stage and resulting in a precursor distribution profile similar to that of untreated ß-thalassemic cells. DIOA up-regulated cyclin-D mRNA levels in late erythropoiesis in both cell models, paralleling changes in the percentage of S-phase-cells. Caspase-3 activity in late erythropoiesis declined to similar degrees in both cell models. DIOA did not modify caspase-3 or -8 mRNA levels.

Interpretation and Conclusions: Ineffective erythropoiesis of in vitro cultured ß-thalassemic cells is likely related to impaired cell maturation. KCC activity appears to contribute to erythroid cell growth during late erythropoiesis.

Key words: erythroid precursors, DIOA, cyclin-D, p21.