Abstract
Lecithin cholesterol acyl transferase (LCAT) deficiency is associated with low high-density lipoprotein (HDL) and the presence of an abnormal lipoprotein called lipoprotein X (Lp-X) that contributes to end-stage renal disease. We examined the possibility of using LCAT an as enzyme replacement therapy agent by testing the infusion of human recombinant (r)LCAT into several mouse models of LCAT deficiency. Infusion of plasma from human LCAT transgenic mice into LCAT-knockout (KO) mice rapidly increased HDL-cholesterol (C) and lowered cholesterol in fractions containing very-low-density lipoprotein (VLDL) and Lp-X. rLCAT was produced in a stably transfected human embryonic kidney 293f cell line and purified to homogeneity, with a specific activity of 1850 nmol/mg/h. Infusion of rLCAT intravenously, subcutaneously, or intramuscularly into human apoA-I transgenic mice showed a nearly identical effect in increasing HDL-C approximately 2-fold. When rLCAT was intravenously injected into LCAT-KO mice, it showed a similar effect as plasma from human LCAT transgenic mice in correcting the abnormal lipoprotein profile, but it had a considerably shorter half-life of approximately 1.23 ± 0.63 versus 8.29 ± 1.82 h for the plasma infusion. rLCAT intravenously injected in LCAT-KO mice crossed with human apolipoprotein (apo)A-I transgenic mice had a half-life of 7.39 ± 2.1 h and increased HDL-C more than 8-fold. rLCAT treatment of LCAT-KO mice was found to increase cholesterol efflux to HDL isolated from mice when added to cells transfected with either ATP-binding cassette (ABC) transporter A1 or ABCG1. In summary, rLCAT treatment rapidly restored the normal lipoprotein phenotype in LCAT-KO mice and increased cholesterol efflux, suggesting the possibility of using rLCAT as an enzyme replacement therapy agent for LCAT deficiency.
Footnotes
This work was supported in part by the Intramural Research Program of the National Institutes of Health National Heart, Lung, and Blood Institute and the National Institutes of Health National Heart, Lung, and Blood Institute [Grant HL09265601].
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
doi:10.1124/jpet.110.169540.
↵ The online version of this article (available at http://jpet.aspetjournals.org) contains supplemental material.
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ABBREVIATIONS:
- LCAT
- lecithin cholesterol acyl transferase
- FLD
- familial lecithin cholesterol acyl transferase deficiency
- FED
- fish eye disease
- LDL
- low-density lipoprotein
- HDL-C
- high-density lipoprotein-cholesterol
- Lp-X
- lipoprotein X
- HDL
- high-density lipoprotein
- RCT
- reverse cholesterol transport
- apo
- apolipoprotein
- rLCAT
- recombinant human lecithin/cholesterol acyl transferase
- KO
- knockout
- Tg
- transgenic
- HEK
- human embryonic kidney
- BSA
- bovine serum albumin
- FPLC
- fast protein liquid chromatography
- BHK
- baby hamster kidney
- ABCA1
- ATP-binding cassette
- DMEM
- Dulbecco's modified Eagle's medium
- CE
- cholesteryl ester(s)
- CETP
- cholesteryl ester transport protein.
- Received April 26, 2010.
- Accepted June 30, 2010.
- U.S. Government work not protected by U.S. copyright
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