RhTyrRS (Y341A), a novel human tyrosyl-tRNA synthetase mutant, stimulates thrombopoiesis through activation of the VEGF-R II/NF-κB pathway

Abstract Bacground and purpose Tumor chemotherapy and radiotherapy induces hematopoietic cell damage, resulting in thrombocytopenia. Conventional platelet transfusion strategies or drug therapies are used to treat thrombocytopenia. However, these therapies may result in a several side effects, including heightened susceptibility to infectious diseases and the formation of anti-TPO-antibodies. Therefore, a more secure strategy should be explored to overcome and compensate for the shortcomings of conventional strategies. Experimental approach Effects of rhTyrRS(Y341A) on the expression of VCAM-1 on the surface of HUVECs were determined by analysing mRNA expression, promoter activity, protein expression. The molecular mechanisms of the effects of rhTyrRS(Y341A) on the expression of VCAM-1 on the surface of HUVECs were investigated by determining the activation of VEGF-R II/NF-κB pathway. Key results Our results provide evidence that rhTyrRS (Y341A) activates NF-κB to upregulate VCAM-1 in a VEGF-R II/NF-κB pathway-dependent, resulting in megakaryocyte adhering to PVECs to induce platelet production. Conclusions This study suggested that rhTyrRS (Y341A), a novel human tyrosyl-tRNA synthetase mutation, increased the platelet count under normal conditions. Further more, we confirmed that an NF-κB-mediated mechanism is involved in rhTyrRS (Y341A)-induced thrombopoiesis, which involves its interaction with VEGF-R II.