Research progress in diffuse axonal injury and its association with Apolipoprotein E polymorphism / 中华创伤杂志

ABSTRACT

Diffuse axonal injury (DAI) is a common primary brain injury.The main mechanism of DAI is the relative displacement of brain tissue junction caused by shearing force during cranial rotation.The pathological changes are the deformation and rupture of white matter nerve fiber bundles.The mechanism of injury and recovery is still unclear,and unified diagnostic criteria are also lacking.Apolipoprotein E (APOE) gene polymorphisms are associated with nervous system development,injury,and repair process.The APOE gene contains six genotypes by the combination among three genes and synthesizes three proteins including apoE2,apoE3 and apoE4.The abnormal spatial structure of apoE4 decreases its ability of transporting lipids,resulting in reduced repair ability after nerve injury.The molecular mechanism of ApoE in the development of axonal injury is complicated.apoE protein can bind to receptor proteins such as low density lipoprotein receptor related protein 1 (LRP1) and heparan sulfate proteoglycan (HSPG) to mediate axonal repair,and it can also damage nerves by influencing calcium influx and producing toxic fragments through hydrolysis.Correcting the abnormal structure of apoE4 is helpful to nerve repair,and apoE analogues also have certain neuroprotective effects.This article reviews the injury characteristics,pathological characteristics,APOE gene polymorphisms,and the role of apoE synthesis in DAI,to provide new insights for elucidation of mechanism of DAI and related clinical application.