Effect Of ApoE4on Mitochondrial Morphology And Function In HEK293Cells

Background: Apolipoprotein E4(ApoE4) is the most known risk factor forAlzheimer’s disease(AD). Epidemiological study found that ApoE4allele carriershave a risk as high as60%to develop to Alzheimer’s disease in their whole life.ApoE4has been reported to play role on mitochondria, however there is no directstudy on ApoE4to study its effect on mitochondria morphology. Since mitochondriamorphology is important for its function, this experiment study ApoE4’s role onmitochondria morphology as well as effect on its function.Objective: To explore the role of ApoE4on mitochondria.Methods: First constructed three EGFP plasmids of ApoE isoforms, namely ApoE2,ApoE3and ApoE4, and then use these constructed plasmids to transfect the HumanEmbryo Kidney293cell lines(HEK293), use mitochondria specific staining labelHEK293cells which have been transfected with fluorescence ApoE4plasmid. Inconfocal microscopy or multi-photon microscopy to observe the morphology change.Then use JC-1to detect the change of mitochondria membrane potential, and detectthe change in production of ATP.Results:1) ApoE4can induce obvious mitochondria abnormality and increase curvedmitochondria.2) ApoE4decreases mitochondria membrane potential；3) ApoE4decreases mitochondria ATP production; 4) In vitro cell transfection with ApoE4decrease the expression of ER stress relatedprotein GADD153and BiP.Conclusion: ApoE4can affect mitochondrial morphology, and increase curvedmitochondria number, these changes in morphology accompanies mitochondriamembrane potential decrease and ATP production decrease; ApoE4doesn’t affect ERstress related protein. These observation implies that ApoE4can directly andspecifically affect mitochondria morphology and function.