Investigating the role of SLFN14 mutations in inherited thrombocytopenia and haematopoiesis

Stapley, Rachel J. (2021). Investigating the role of SLFN14 mutations in inherited thrombocytopenia and haematopoiesis. University of Birmingham. Ph.D.

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Abstract

Schlafen 14 (SLFN14) has recently been identified as an endoribonuclease responsible for cleaving RNA to regulate and inhibit protein synthesis. Early studies revealed members of the SLFN family are capable of altering lineage commitment during T-cell differentiation, using cell cycle arrest as a means of translational control. SLFN14 mutations have been previously reported as causing inherited macrothrombocytopenia and bleeding in patients. The aim of this thesis was to uncover potential mechanisms for how SLFN14 and its mutations contribute to inherited thrombocytopenia and altered haematopoiesis. A novel CRISPR knock-in mouse of SLFN14-K208N and platelet specific knock-out mouse using the PF4Cre loxP system were used to better understand the involvement of SLFN14 in haematopoiesis and platelet function. Gross haematological analysis, in vitro and in vivo studies of platelet and erythrocyte function, as well as analysis of spleen and bone marrow progenitors were used. Homozygous mice for the K208N mutation do not survive to weaning age due to severe anaemia. Heterozygotes exhibit microcytic erythrocytosis, haemolytic anaemia, splenomegaly and abnormal thrombus formation examined by intravital microscopy although in vitro platelet function and morphology remain unchanged. RT-PCR of transcription factor GATA1 in SLFN14-K208N mice revealed significant reduction in GATA1 mRNA from whole bone marrow suggesting the SLFN14 endoribonuclease is active in haematopoiesis. In addition, SLFN14 PF4Cre mice show macrothrombocytopenia with reduced proportion of megakaryocytes in the bone marrow although platelet function was retained. This suggests SLFN14 is a key regulator in mammalian haematopoiesis and a species-specific mediator in platelet and erythrocyte production and function.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):