Actin polymerization in neutrophils from patients affected by myelodysplastic syndromes—A flow cytometric study

• Published in: Leukemia research Vol. 21; no. 6; pp. 513 - 518
• Main Authors: Carulli, Giovanni, Sbrana, Silverio, Minnucci, Sistina, Azzarà, Antonio, Angiolini, Claudia, Gullaci, Angela Rizzuti, Ambrogi, Fabio
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.1997; Elsevier Science
• Subjects: Actin; actin polymerization; Actins - blood; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Biopolymers; cytoskeleton; Female; Flow Cytometry; Hematologic and hematopoietic diseases; Humans; Kinetics; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Male; Medical sciences; Middle Aged; myelodysplastic syndromes; Myelodysplastic Syndromes - blood; N-Formylmethionine Leucyl-Phenylalanine - pharmacology; neutrophils; Neutrophils - drug effects; Neutrophils - metabolism; PBS; fMLP; cytoskeleton; FAB; RAEB; RA; actin polymerization; RAEB-t; CMMoL; Actin; RARS; myelodysplastic syndromes; flow cytometry; neutrophils; MDS; Human; Flow cytometry; Granulocyte; Actins; Polymerization; Cytoskeleton; Exploration; Neutrophil; Myelodysplastic syndrome
• ISSN: 0145-2126; 1873-5835
• DOI: 10.1016/S0145-2126(97)00009-X

In this study F-actin polymerization in neutrophils from 21 patients affected by myelodysplastic syndromes (MDS) was evaluated by means of a flow cytometric assay. Neutrophils were stimulated with formyl-methionyl-leucyl-phenylanaline (fMLP; 10 −8 M final concentration) for 15, 30, 60 and 120 sec, and F-actin content was determined using fluorescein-isothiocyanate phallacidin as a specific probe. Eight normal subjects were studied as controls. We found that F-actin polymerization was defective in ten patients, with very impaired values after 60 and 120 sec of stimulation with fMLP. The remaining 11 patients showed a prevalent neutrophil population with normal F-actin polymerization and neutrophil sub-populations with either defective or undetectable F-actin polymerization. In the first group, patients with very poor prognosis (refractory anemia with excess blasts, refractory anemia with excess blasts in leukemic transformation, trisomy 8, multiple karyotypic abnormalities) were present, although patients with aberrations of karyotype were present in the second group. It is possible that defects in neutrophil F-actin polymerization may be responsible for neutrophil dysfunction, which has frequently been observed in MDS.