Apolipoprotein E-deficient lipoproteins induce foam cell formation by downregulation of lysosomal hydrolases in macrophages

Dong Fang Wu, Chakradhari Sharan, Hong Yang, J. Shawn Goodwin, Lichun Zhou, Gregory A. Grabowski, Hong Du, Zhong Mao Guo

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Apolipoprotein E (apoE) deficiency has been suggested to induce foam cell formation. Using lipoproteins obtained from wild-type mice and apoE-deficient mice expressing apoB-48 but not apoB-100, we studied apoE-deficient lipoprotein-induced changes in lipoprotein catabolism and protein expression in mouse peritoneal macrophages (MPMs). Our data demonstrate that incubation of MPMs with apoE-deficient lipoproteins induced intracellular lipoprotein, cholesteryl ester, and triglyceride accumulation, which was associated with a time-related decline in apoE-deficient lipoprotein degradation in MPMs. Confocal microscopy analysis indicated that the accumulated lipids were localized in lysosomes. ApoE-deficient lipoproteins reduced the protein levels of lysosomal acid lipase, cathepsin B, and cation-dependent mannose 6 phosphate receptor (MPR46). Exogenous apoE reduced apoE-deficient lipoprotein-induced lipid accumulation and attenuated the suppressive effect of apoE-deficient lipoproteins on lysosomal hydrolase and MPR46 expression. Although oxidized lipoproteins also increased lipid contents in MPMs, exogenous apoE could not attenuate oxidized lipoprotein-induced lipid accumulation. Our in vivo studies also showed that feeding apoE-deficient mice a high-fat diet resulted in cholesteryl ester and triglyceride accumulation and reduced lysosomal hydrolase expression in MPMs. These data suggest that apoE-deficient lipoproteins increase cellular lipid contents through pathways different from those activated by oxidized lipoproteins and that reducing lysosomal hydrolases in macrophages might be a mechanism by which apoE-deficient lipoproteins result in intralysosomal lipoprotein accumulation, thereby inducing foam cell formation.

Original languageEnglish (US)
Pages (from-to)2571-2578
Number of pages8
JournalJournal of Lipid Research
Volume48
Issue number12
DOIs
StatePublished - Dec 1 2007
Externally publishedYes

Fingerprint

Foam Cells
Macrophages
Apolipoproteins E
Hydrolases
Lipoproteins
Foams
Down-Regulation
Peritoneal Macrophages
Lipids
Cholesterol Esters
Triglycerides
Apolipoprotein B-48
Apolipoprotein B-100
Sterol Esterase
Cathepsin B
Confocal microscopy
High Fat Diet
Nutrition
Lysosomes
Lipase

Keywords

  • Cholesterol ester
  • Mannose 6 phosphate receptor
  • Oxidized lipoproteins

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Cell Biology

Cite this

Apolipoprotein E-deficient lipoproteins induce foam cell formation by downregulation of lysosomal hydrolases in macrophages. / Wu, Dong Fang; Sharan, Chakradhari; Yang, Hong; Goodwin, J. Shawn; Zhou, Lichun; Grabowski, Gregory A.; Du, Hong; Guo, Zhong Mao.

In: Journal of Lipid Research, Vol. 48, No. 12, 01.12.2007, p. 2571-2578.

Research output: Contribution to journalArticle

Wu, Dong Fang ; Sharan, Chakradhari ; Yang, Hong ; Goodwin, J. Shawn ; Zhou, Lichun ; Grabowski, Gregory A. ; Du, Hong ; Guo, Zhong Mao. / Apolipoprotein E-deficient lipoproteins induce foam cell formation by downregulation of lysosomal hydrolases in macrophages. In: Journal of Lipid Research. 2007 ; Vol. 48, No. 12. pp. 2571-2578.
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AU - Sharan, Chakradhari

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AU - Zhou, Lichun

AU - Grabowski, Gregory A.

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AU - Guo, Zhong Mao

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