| First Author | Baez JM | Year | 2005 |
| Journal | Biochem J | Volume | 388 |
| Issue | Pt 1 | Pages | 57-63 |
| PubMed ID | 15628972 | Mgi Jnum | J:115284 |
| Mgi Id | MGI:3691310 | Doi | 10.1042/BJ20041899 |
| Citation | Baez JM, et al. (2005) Decreased lipid efflux and increased susceptibility to cholesterol-induced apoptosis in macrophages lacking phosphatidylcholine transfer protein. Biochem J 388(Pt 1):57-63 |
| abstractText | Macrophages are the predominant cellular component of atherosclerotic lesions, where they scavenge oxidatively modified lipoproteins while defending themselves against cholesterol-induced cytotoxicity by adaptive mechanisms that depend in part on the synthesis, distribution and efflux of phosphatidylcholines. PC-TP (phosphatidylcholine transfer protein) is a START (steroidogenic acute regulatory protein-related lipid transfer) domain protein that catalyses the intermembrane transfer of phosphatidylcholines and promotes apolipoprotein AI-mediated lipid efflux when overexpressed in the cytosol of Chinese-hamster ovary cells. To explore a role for PC-TP in the adaptive responses of macrophages to cholesterol loading, we utilized peritoneal macrophages from mice with homozygous disruption of the gene encoding PC-TP (Pctp(-/-)) and wild-type littermate controls. PC-TP was abundantly expressed in macrophages from wild-type but not Pctp(-/-) mice. In cholesteryl ester-loaded macrophages from Pctp(-/-) mice, the apolipoprotein AI-mediated efflux of phospholipids and cholesterol was decreased. This could be attributed to proportional decreases in the expression levels of ATP-binding cassette A1. Also, in response to free cholesterol loading, the absence of PC-TP from macrophages was associated with marked increases in apoptotic cell death. These findings suggest that PC-TP in macrophages may serve an atheroprotective role by defending against cholesterol-induced cytotoxicity. |
