Study On Cardiac Injury And Mechanism Of ZIKV Infection

Objective:ZIKV infection has posed a serious threat to global health.There have been clinical reports of cardiac injury caused by ZIKV infection,but no relevant studies have been reported.In order to clarify the characteristics and mechanism of heart injury caused by ZIKV infection,found drugs to improve heart function and improve the clinical treatment rate of ZIKV infection.This study intends to establish a heart infection model of ZIKV in vivo and in vitro,to study whether ZIKV infection will cause heart injury and the mechanism of heart injury,and to analyze the role of cell surface receptors and cell autophagy in heart injury caused by ZIKV infection,so as to provide a theoretical basis for further research on anti-infection injury drugs.Methods:In this study,animal and cell models of ZIKV infected heart were firstly established,using qPCR to detect the viral load in the infected tissue and cell supernatant to indicate the infection of the heart.Then,ELISA was used to detect the changes of cardiac injury markers in the infected serum and cell supernatant to indicate the damage of the heart.Finally,flow cytometry and Western blot were used to further explore ZIKV infection cause heart damage mechanism.Results:(1)In vivo model of ZIKV infection was successfully established.The viral load was brain>heart>lung>liver.The maximum viral load of heart was 2.94×106copies/μg on post infection day 3,liver was 4.9×104copies/μg on post infection day 3,lung was 9.2×105copies/μg on post infection day 5,and brain was 1.16×1014copies/μg on post infection day 7.(2)The model of ZIKV infected heart in vitro was established successfully.The viral load of infection supernatant was proportional to infection titer and infection time.The infected supernatant could induce the plaque of Vero cells,which proved the reinfection of the progeny virus.The replication kinetics of ZIKV in HL-1 cells was consistent with that in Vero cells.The maximum value of intracellular ZIKV replication occurred 24 hours after infection,and the maximum value of extracellular ZIKV replication occurred 48 hours after infection.(3)The changes of cardiac injury markers CK-MB,BNP and cTnT showed statistical differences in infected animal serum and cell infection supernatant,indicating the existence of cardiac injury.(4)AXL and Tyro3 receptors were expressed on the surface of HL-1 cells,and blocking the receptor could effectively reduce the ZIKV viral load of HL-1 cells,but ZIKV infection did not cause changes in the receptor expression.(5)The expression of autophagy marker protein LC3B in the heart tissue of ZIKV-infected A129 mice and cardiomyocyte HL-1 was changed.The increased expression of LC3B after infection was statistically significant,indicating the increase of autophagyand.(6)Knockdown of AXL and Tyro3 receptors did not affect the expression of autophagy marker protein LC3B in HL-1 cells infected with ZIKV.Conclusion:ZIKV can successfully infect the heart and cause damage to the heart.The expression of AXL and Tyro3 receptors on the surface of myocardial cells can affect the ZIKV viral load of HL-1 cells,and ZIKV infection can lead to the increase of autophagy level in the heart.The two mechanisms of heart injury caused by ZIKV infection,cell surface receptor and cell autophagy,were found,which provided a certain theoretical basis for studying the detailed injury mechanism,provides an idea for studying the mechanism of cardiac injury caused by ZIKV infection,and will contribute to the clinical treatment of ZIKV infection.