hAPOE2

This APOE2 humanized mouse model was established by replacing the mouse Apoe gene coding exons and introns with the human APOE2 corresponding sequence by homologous recombination.

Fig.1 Detection of APOE expression in brain and liver by RT-PCR. Mouse Apoe mRNA (193 bp) was detectable only in wild-type C57BL/6 mice but not in hAPOE knockin mice. Human APOE mRNA (207 bp) was detectable only in homozygous hAPOE2 knockin mice but not in wild-type mice. Tissue RNA was extracted from wild-type C57BL/6 mice (WT) and homozygous hAPOE2 knockin mice (HO) (n=5 per group, male, 7 weeks old), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mRNA primers.

Fig.2 Detection of human APOE(A) and mouse APOE(B) expression in serum of WT C57BL/6 mice and HO hAPOE2 mice by ELISA.  Mouse APOE was exclusively detectable in wild-type C57BL/6 mice but not in hAPOE2 knockin mice, and human APOE was exclusively detectable in homozygous hAPOE2 knockin mice. Serum samples were collected from wild-type C57BL/6 mice and HO hAPOE2 mice (n=5 per group, male, 7 weeks old), and analyzed by ELISA with an anti-mAPOE ELISA kit and an anti-hAPOE ELISA kit. 

Abbr. HO, homozygous; WT, wild type.

Fig.3 Detection of human APOE(A) and mouse APOE(B) expression in brain of WT C57BL/6 mice and HO hAPOE2 mice by ELISA.  Mouse APOE was exclusively detectable in the brain of WT C57BL/6 mice but absent in hAPOE2 knockin mice. Human APOE was positively detectable in the brain of homozygous hAPOE2 knockin mice, although the kit exhibited non-specific detection in brain lysates of WT mice. Brain tissues lysates were collected from WT C57BL/6 mice and HO hAPOE2 mice (n=5 per group, male, 7 weeks old), and analyzed by ELISA with an anti-mAPOE ELISA kit and an anti-hAPOE ELISA kit. 

Abbr.  HO, homozygous; WT, wild type; N.D., not detectable.

Fig.4 Detection of human APOE(A) and mouse APOE(B) expression in liver of WT C57BL/6 mice and HO hAPOE2 mice by ELISA. Mouse APOE was exclusively detectable in the liver of WT C57BL/6 mice but absent in hAPOE2 knockin mice. Human APOE was positively detectable in the liver of homozygous hAPOE2 knockin mice, although the kit exhibited non-specific detection in liver lysates of WT mice. Liver tissues lysates were collected from WT C57BL/6 mice and HO hAPOE2 mice (n=5 per group, male, 7 weeks old), and analyzed by ELISA with an anti-mAPOE ELISA kit and an anti-hAPOE ELISA kit. 

Abbr. HO, homozygous; WT, wild type; N.D., not detectable.

Fig.5 Blood lipid profiles of hAPOE2 knockin mice. Homozygous hAPOE2 mice exhibited significantly elevated serum TG, T-CHO and LDL-C levels compared to wild-type C57BL/6 mice, indicating the lipid dysmetabolism in hAPOE2 knockin mice. Serum samples were collected from wild-type C57BL/6 mice and HO hAPOE2 mice (n=5 per group, male, 7 weeks old) to measure levels of (A) triglycerides (TG), (B) total cholesterol (T-CHO), (C) high-density lipoprotein cholesterol (HDL-C) and (D) low-density lipoprotein cholesterol (LDL-C (n=5 per group, Mean ± SEM, t-test, *p < 0.05, ***p < 0.001, ****p < 0.0001, ns, no significance). 

Abbr. HO, homozygous; WT, wild type.