Hyplip2, a new gene for combined hyperlipidemia and increased atherosclerosis.
OBJECTIVE
We previously reported the mapping of a quantitative trait locus (QTL) on chromosome 15 contributing to hyperlipidemia in a cross between inbred strains MRL/MpJ (MRL) and BALB/cJ (BALB). Using marker-assisted breeding, we constructed a congenic strain in which chromosome 15 interval from MRL is placed on the genetic background of BALB. The congenic allowed us to confirm the QTL result and to further characterize the properties and location of the underlying gene.


RESULTS
On chow and high-fat (atherogenic) diets, the congenic mice exhibited higher levels of plasma triglycerides and cholesterol than BALB mice. In response to the atherogenic diet, the congenic mice but not BALB mice exhibited a dramatic approximately 30-fold increase in atherogenic lesions accompanied by approximately 2-fold decrease in high-density lipoprotein cholesterol levels. With respect to atherosclerotic lesions and some lipid parameters, this chromosome 15 gene, designated Hyplip2, exhibited dominant inheritance. Expression array analyses suggested that Hyplip2 may influence inflammatory and bile acid synthesis pathways. Finally, we demonstrated the usefulness of subcongenic strains to narrow the locus (50 Mbp) with the goal of positionally cloning Hyplip2.


CONCLUSIONS
Our data demonstrate that the Hyplip2 gene significantly contributes to combined hyperlipidemia and increased atherosclerosis in mice.
Department of Medicine,University of California, Los Angeles 90095-1679, USA.
Xuping
X
Wang
Peter
P
Gargalovic
Jack
J
Wong
Jennifer L
JL
Gu
Xiaohui
X
Wu
Hongxiu
H
Qi
Pingzi
P
Wen
Li
L
Xi
Bing
B
Tan
Rocky
R
Gogliotti
Lawrence W
LW
Castellani
Aurobindo
A
Chatterjee
Aldons J
AJ
Lusis
D000818:Animals; D020296:Animals, Congenic; D001161:Arteriosclerosis / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping / Q000379:methods; D003433:Crosses, Genetic; D004036:Diet, Atherogenic; D005796:Genes / Q000502:physiology; D006949:Hyperlipidemias / Q000235:genetics* / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D051379:Mice; D020297:Mice, Congenic; D008807:Mice, Inbred BALB C; D019463:Mice, Inbred MRL lpr; D040641:Quantitative Trait Loci / Q000235:genetics
D008055:Lipids