Pretražite po imenu i prezimenu autora, mentora, urednika, prevoditelja

Napredna pretraga

Pregled bibliografske jedinice broj: 1173609

The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production


Ivana Bertović
The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production, 2021., doktorska disertacija, Odjel za biotehnologiju, Rijeka


CROSBI ID: 1173609 Za ispravke kontaktirajte CROSBI podršku putem web obrasca

Naslov
The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production

Autori
Ivana Bertović

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Odjel za biotehnologiju

Mjesto
Rijeka

Datum
22.03

Godina
2021

Stranica
151

Mentor
Antonija Jurak Begonja

Ključne riječi
megakariociti, PI3P, Rab GTPaze, lizosomi, jezgrica
(megakaryocytes, PI3P, Rab GTPases, lysosomes, nucleolus)

Sažetak
The maturation of megakaryocytes (MKs) implies the polyploidization of the nucleus and the formation of a demarcation membrane system (DMS), an extensive internal membrane reservoir necessary for platelet production. While the initiation of the DMS starts with plasma membrane invagination and continues in the perinuclear region by the insertion of Golgi-derived vesicles, the membrane source(s) and mechanism for further DMS expansion, cell growth, and proplatelet formation remain elusive. In the present study, we investigated the role of endolysosomal system during MKs maturation and platelet production. Vps34 kinase and its product lipid phosphatidylinositol 3-monophosphate (PI3P) are key components of early and late endosomes where they regulate vesicular trafficking. We demonstrate that, during maturation, Vps34-derived PI3P translocates from the perinuclear early endosomes (EE) in immature, to peripheral late endosomes/lysosomes (LE/Lys) in mature MKs. Moreover, PI3P was found in close contact with PI(4, 5)P2 (plasma membrane/DMS) and LE/Lys in mature MKs. Sequestration of PI3P by expression of 2xFYVE domain, specific pharmacological inhibition of Vps34-mediated PI3P production, or depletion of PI3P by expression of PI3P-phosphatase (MTM1) decreased proplatelet formation. At the same time, inhibition of PI3P production led to the intracellular accumulation of LE/Lys markers preventing their surface expression, suggesting an essential role for PI3P in LE/Lys translocation toward the plasma membrane. Moreover, inhibition of Vps34 at earlier stages of MK maturation caused aberrant DMS development, decreased the size of MKs, and the expression of GPIb, a DMS marker. In line with the above was targeting of downstream events in endosome maturation: overexpression of the dominant-negative late endosomal GTPase Rab7 T22N or pharmacological inhibition of PI3P conversion to PI(3, 5)P2 led to the enlarged LE/Lys, reduced surface levels of LE/Lys markers, and decreased proplatelet formation. In parallel, we investigated the role of early endosomal GTPase Rab5 which regulates endocytic uptake and represents the starting point for endosome maturation. In addition, Rab5 mediates the recruitment of Vps34 on the membrane of EEs, which is a key step during early-to-late endosome maturation. Rab5 mutants expressed from retroviruses showed the opposing effects on EE morphology and the amount of endocytosis in MKs. Active Rab5 Q79L induced the formation of large EEs that accumulated GPIb, increased transferrin internalization, and at the same time increased proplatelet production. In contrast, inactive Rab5 N133L caused EE fragmentation, GPIb retention at the plasma membrane, impaired transferrin endocytosis, and strongly blocked proplatelet formation. Furthermore, active Rab5 Q79L increased membrane labeling by lipophilic dye PKH26 suggesting that the increased levels of the endocytosis might contribute to the internal membrane content in MKs. Together, these results suggest that PI3P-positive LE/Lys contribute to the membrane growth and proplatelet formation by their translocation to the cell periphery and fusion with the plasma membrane, while early endosomal Rab5 regulates GPIb trafficking and represents the limiting step during endocytosis in MKs, the amount of which we believe is a major determinant of membrane growth and proplatelet production.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Interdisciplinarne prirodne znanosti, Temeljne medicinske znanosti, Biotehnologija



POVEZANOST RADA


Projekti:
HRZZ-UIP-2014-09-2400 - Uloga fosfoinozitida u nastanku trombocita (MkPI) (Jurak Begonja, Antonija, HRZZ - 2014-09) ( POIROT)
Ostalo-CRP/HRV15-04_EC - Deciphering the role of phosphoinositol lipids in thrombopoiesis (Jurak Begonja, Antonija, Ostalo - CRP-ICGEB Early Career Return Grant) ( POIROT)
NadSve-Sveučilište u Rijeci-uniri-biomed-18-188-1343 - Identifikacija novih interakcijskih partnera Vps34 u megakariopoezi (Jurak Begonja, Antonija, NadSve - UNIRI projekti 2018) ( POIROT)
Ostalo-ASH-2019 - Nucleolar control of megakaryopoiesis (NucMeg) (Jurak Begonja, Antonija, Ostalo - American Society of Hematology (ASH) Global Research Award) ( POIROT)

Ustanove:
Sveučilište u Rijeci - Odjel za biotehnologiju

Profili:

Avatar Url Ivana Bertović (autor)

Avatar Url Antonija Jurak Begonja (mentor)


Citiraj ovu publikaciju:

Ivana Bertović
The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production, 2021., doktorska disertacija, Odjel za biotehnologiju, Rijeka
Ivana Bertović (2021) 'The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production', doktorska disertacija, Odjel za biotehnologiju, Rijeka.
@phdthesis{phdthesis, year = {2021}, pages = {151}, keywords = {megakariociti, PI3P, Rab GTPaze, lizosomi, jezgrica}, title = {The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production}, keyword = {megakariociti, PI3P, Rab GTPaze, lizosomi, jezgrica}, publisherplace = {Rijeka} }
@phdthesis{phdthesis, year = {2021}, pages = {151}, keywords = {megakaryocytes, PI3P, Rab GTPases, lysosomes, nucleolus}, title = {The role of phosphatidylinositol 3-monophosphate (PI3P) in megakaryocyte maturation and platelet production}, keyword = {megakaryocytes, PI3P, Rab GTPases, lysosomes, nucleolus}, publisherplace = {Rijeka} }




Contrast
Increase Font
Decrease Font
Dyslexic Font