PB0728 - Role of the mechanotransductor PIEZO1 in megakaryocyte differentiation

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Co-Author(s)

JD

Julien Demagny

PharmD
HEMATIM UE4666, Univ. Picardie Jules Verne
Amiens, Picardie, France
SP

Sonia Poirault-Chassac

Engineer
Université Paris Cité, Inserm UMR-S 1140
Paris, Ile-de-France, France
DI

Damtz Nehemie Ilsaint

Student
HEMATIM UE4666, Univ. Picardie Jules Verne
Amiens, Picardie, France
AM

Aurore Marchelli

Technician
Université Paris Cité, Inserm UMR-S 1140
Paris, Ile-de-France, France
HO

Hakim Ouled-Haddou

PhD
HEMATIM UE4666, Univ. Picardie Jules Verne
Amiens, Picardie, France
ML

Maïlys Le Guyader

MD
Biological Hematology Department, CHU Amiens-Picardie
amiens, Picardie, France
PG

Pascale Gaussem

PharmD, PhD
Université Paris Cité, Inserm UMR-S1140, Hôpital Européen Georges Pompidou
Paris, Ile-de-France, France
LG

Loïc Garçon

MD, PhD, Prof
HEMATIM UE4666, Univ. Picardie Jules Verne
Amiens, Picardie, France

Presenting Author(s)

CB

Christilla Bachelot-Loza, PhD

PhD
Université Paris Cité, Inserm UMR-S 1140
Paris, Ile-de-France, France

Background: From hematopoietic stem cells to megakaryocytes (Mks), cells undergo various mechanical forces that affect Mk differentiation, maturation and proplatelet formation. PIEZO1, a recently identified mechanotransductor, appears to be a natural candidate for sensing these mechanical forces and regulating megakaryopoiesis and thrombopoiesis. Gain of function mutations of PIEZO1 gene are responsible for hereditary xerocytosis, a haemolytic anaemia associated with thrombotic events

Aims: Characterization of the PIEZO1 role in megakaryopoiesis.

Methods: HEL cell line and primary CD34+ human cells were driven in vitro towards Mk differentiation. Using YODA1 and a shRNA based knock-down strategy, we evaluated step by step the effects of PIEZO1 during megakaryopoiesis, i.e the Mk commitment (flow cytometry was used to analyze calcium flux, ploidy using DAPI, and CD41+ and CD42+ expression) and the endomitosis process (DAPI labeling quantification by flow cytometry). Proplatelet formation was analyzed by inverted light microscopy.

Results: PIEZO1 activation by 4 µM YODA1 at early stages of culture induced cytosolic calcium ion influx and delayed cell maturation. Indeed, CD41+CD42+ cell numbers were reduced by around 1.5-fold, with no effects on proliferation. At later stages of Mk differentiation, PIEZO1 activation promoted endomitosis and proplatelet formation that was reversed by PIEZO1 gene invalidation with a ShRNA-PIEZO1. Same observations on endomitosis were reproduced in HEL cells induced into Mks by PMA and treated with YODA1.

Conclusion(s): We show here the dual role of a chronic activation of PIEZO1 on megakaryopoiesis, with an inhibitory effect during the first stages of Mk differentiation and a positive effect during late Mk maturation leading to a higher ploidy and an increased proplatelet formation.