A Study Based On RUNX-1 And GATA2 Gene Overexpression To Promote Hematopoietic System Repair In Hematopoietic Injury Mice

Bone marrow is one of the most radiation-sensitive tissues.Whole body irradiation doses > 1.0 Gy can cause damage to the hematopoietic system of the irradiated individuals,reduce the number of hematopoietic stem cells in the bone marrow,change the peripheral blood hemogram,and significantly reduce white blood cells,platelets,and red blood cells.When a large dose of radiation(> 3.5Gy)causes severe damage to the hematopoietic system of the exposed person,the number of hematopoietic stem / progenitor cells in the patient’s body is extremely reduced.Without treatment,the patient is likely to die from bone marrow radiation disease.In addition to the damage caused by bone marrow hematopoietic cells,chemotherapy drugs such as carboplatin can also cause damage to the hematopoietic system.Therefore,it is particularly important to find treatments that promote the recovery of the hematopoietic system.The somatic lineage reprogramming technology that has appeared in recent years provides new ideas for finding new sources of hematopoietic cells.Studies have shown that the use of transcription factor overexpression in vivo can promote the reprogramming of specific adult cells into cells of another lineage.For example,skin fibroblasts overexpress GATA2,Lmo2,Myc,n Pitx2,Sox17,and Tal1 transcription factors.Promote its transformation into endothelial cells,thereby promoting angiogenesis.There is also the use of reprogramming technology to transform fibroblasts into keratinocytes to promote the repair of skin tissues;reprogram the fibroblasts into astrocytes to promote the repair of the nervous system.The liver and hematopoietic cells are closely related in development.We intend to use the strategy of hematopoietic transcription factor overexpression in the liver to explore whether liver cells have the potential to transdifferentiate into hematopoietic cells.In order to achieve the overexpression of hematopoietic transcription factors in the liver,we used hydrodynamics-based transfection to achieve this goal.Hydrodynamic transfection method is a method of rapid injection of a large volume of plasmid DNA solution from the tail vein of mice to obtain the expression of transgenes.This method was established by scientists such as Liu in 1999.It mixes a plasmid containing the expression of the target gene into physiological saline and injects it into the mouse from the tail vein through high-pressure transfection.Most plasmids can be expressed in the liver..And the plasmid introduced into the mouse body by this method is transient transfection,which is a transient change.The highest expression level is 1-3 days after transfection,and then the expression level decreases until it disappears.It will not cause long-term effects on the liver of the animal.It is safe.Sex is higher.The transcription factors we screened are RUNX1 and GATA2 genes.RUNX1,also known as AML1(acute myeloid leukemia 1),is a member of the core binding factor(CBF)family.RUNX1 has been confirmed in previous studies as indispensable in the early process of hematopoietic differentiation.The lack of key regulatory factors plays a regulatory role in the regulation and differentiation of hematopoietic stem cells.The GATA2 gene is a key regulator of hematopoietic cell development and maintenance.Deletion of the GATA2 gene in mice shows that it is essential for embryogenesis of hematopoietic stem cells(HSC)and hematopoietic progenitor cells(HPC).In embryos it functions during the transition from hematopoietic endothelial cells to hematopoietic cells to affect hematopoietic clusters and reduces the formation of hematopoietic stem cells(HSC)and hematopoietic progenitor cells(HPC).RUNX1 and GATA2 genes are key regulators of hematopoietic cell development and maintenance.RUNX1 and GATA2 genes play a vital role in the entire hematopoietic process.In this study,an expression vector containing the hematopoietic transcription factors RUNX1 c and GATA2 genes was successfully constructed,and the expression vectors of RUNX1 c and GATA2 in mouse liver were achieved by hydrodynamic transfection,and transfected in the case of mouse hematopoietic system damage.Fourteen days after double plasmid infection,megakaryocytes in the bone marrow and peripheral blood increased,peripheral blood platelets increased,bone marrow hematopoietic stem cells,and megakaryocyte progenitors increased;and hematopoietic stem cells increased in mouse liver,and liver cells colonized after 14 days In the experiment,hematopoietic colonies were detected.It lays a foundation for further studying the effects of over-expressing hematopoietic transcription factors in liver on hepatocytes and hematopoietic system.