TY - JOUR
T1 - Germline variants in ETV6 underlie reduced platelet formation, platelet dysfunction and increased levels of circulating CD34+ progenitors
AU - NIHR BioResource
AU - Poggi, Marjorie
AU - Canault, Matthias
AU - Favier, Marie
AU - Turro, Ernest
AU - Saultier, Paul
AU - Ghalloussi, Dorsaf
AU - Baccini, Veronique
AU - Vidal, Lea
AU - Mezzapesa, Anna
AU - Chelghoum, Nadjim
AU - Mohand-Oumoussa, Badreddine
AU - Falaise, Céline
AU - Favier, Rémi
AU - Ouwehand, Willem H.
AU - Fiore, Mathieu
AU - Peiretti, Franck
AU - Morange, Pierre Emmanuel
AU - Saut, Noémie
AU - Bernot, Denis
AU - Greinacher, Andreas
AU - Nurden, Paquita
AU - Nurden, Paquita
AU - Freson, Kathleen
AU - Raslova, Hana
AU - Alessi, Marie Christine
AU - Trégouët, David Alexandre
N1 - Publisher Copyright:
© 2017 Ferrata Storti Foundation.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Variants in ETV6, which encodes a transcription repressor of the E26 transformation-specific family, have recently been reported to be responsible for inherited thrombocytopenia and hematologic malignancy. We sequenced the DNA from cases with unexplained dominant thrombocytopenia and identified six likely pathogenic variants in ETV6, of which five are novel. We observed low repressive activity of all tested ETV6 variants, and variants located in the E26 transformation-specific binding domain (encoding p.A377T, p.Y401N) led to reduced binding to corepressors. We also observed a large expansion of megakaryocyte colony-forming units derived from variant carriers and reduced proplatelet formation with abnormal cytoskeletal organization. The defect in proplatelet formation was also observed in control CD34+ cell-derived megakaryocytes transduced with lentiviral particles encoding mutant ETV6. Reduced expression levels of key regulators of the actin cytoskeleton CDC42 and RHOA were measured. Moreover, changes in the actin structures are typically accompanied by a rounder platelet shape with a highly heterogeneous size, decreased platelet arachidonic response, and spreading and retarded clot retraction in ETV6 deficient platelets. Elevated numbers of circulating CD34+ cells were found in p.P214L and p.Y401N carriers, and two patients from different families suffered from refractory anemia with excess blasts, while one patient from a third family was successfully treated for acute myeloid leukemia. Overall, our study provides novel insights into the role of ETV6 as a driver of cytoskeletal regulatory gene expression during platelet production, and the impact of variants resulting in platelets with altered size, shape and function and potentially also in changes in circulating progenitor levels.
AB - Variants in ETV6, which encodes a transcription repressor of the E26 transformation-specific family, have recently been reported to be responsible for inherited thrombocytopenia and hematologic malignancy. We sequenced the DNA from cases with unexplained dominant thrombocytopenia and identified six likely pathogenic variants in ETV6, of which five are novel. We observed low repressive activity of all tested ETV6 variants, and variants located in the E26 transformation-specific binding domain (encoding p.A377T, p.Y401N) led to reduced binding to corepressors. We also observed a large expansion of megakaryocyte colony-forming units derived from variant carriers and reduced proplatelet formation with abnormal cytoskeletal organization. The defect in proplatelet formation was also observed in control CD34+ cell-derived megakaryocytes transduced with lentiviral particles encoding mutant ETV6. Reduced expression levels of key regulators of the actin cytoskeleton CDC42 and RHOA were measured. Moreover, changes in the actin structures are typically accompanied by a rounder platelet shape with a highly heterogeneous size, decreased platelet arachidonic response, and spreading and retarded clot retraction in ETV6 deficient platelets. Elevated numbers of circulating CD34+ cells were found in p.P214L and p.Y401N carriers, and two patients from different families suffered from refractory anemia with excess blasts, while one patient from a third family was successfully treated for acute myeloid leukemia. Overall, our study provides novel insights into the role of ETV6 as a driver of cytoskeletal regulatory gene expression during platelet production, and the impact of variants resulting in platelets with altered size, shape and function and potentially also in changes in circulating progenitor levels.
UR - http://www.scopus.com/inward/record.url?scp=85011589641&partnerID=8YFLogxK
U2 - 10.3324/haematol.2016.147694
DO - 10.3324/haematol.2016.147694
M3 - Article
C2 - 27663637
AN - SCOPUS:85011589641
SN - 0390-6078
VL - 102
SP - 282
EP - 294
JO - Haematologica
JF - Haematologica
IS - 2
ER -