title: Adipocyte phospholipid transfer protein and lipoprotein metabolism.
abstract: OBJECTIVE
  Phospholipid transfer protein (PLTP) is highly expressed in adipose tissues. Thus, the effect of adipose tissue PLTP on plasma lipoprotein metabolism was examined.
  
  
  RESULTS
  We crossed PLTP-Flox-ΔNeo and adipocyte protein 2 (aP2)-Cre recombinase (Cre) transgenic mice to create PLTP-Flox-ΔNeo/aP2-Cre mice that have a 90 and a 60% reduction in PLTP mRNA in adipose tissue and macrophages, respectively. PLTP ablation resulted in a significant reduction in plasma PLTP activity (22%), high-density lipoprotein-cholesterol (21%), high-density lipoprotein-phospholipid (20%), and apolipoprotein A-I (33%) levels, but had no effect on nonhigh-density lipoprotein levels in comparison with those of PLTP-Flox-ΔNeo controls. To eliminate possible effects of PLTP ablation by macrophages, we lethally irradiated PLTP-Flox-ΔNeo/aP2-Cre mice and PLTP-Flox-ΔNeo mice, and then transplanted wild-type mouse bone marrow into them to create wild-type→PLTP-Flox-ΔNeo/aP2-Cre and wild-type→PLTP-Flox-ΔNeo mice. Thus, we constructed a mouse model (wild-type→PLTP-Flox-ΔNeo/aP2-Cre) with PLTP deficiency in adipocytes but not in macrophages. These knockout mice also showed significant decreases in plasma PLTP activity (19%) and cholesterol (18%), phospholipid (17%), and apolipoprotein A-I (26%) levels. To further investigate the mechanisms behind the reduction in plasma apolipoprotein A-I and high-density lipoprotein lipids, we measured apolipoprotein A-I-mediated cholesterol efflux in adipose tissue explants and found that endogenous and exogenous PLTP significantly increased cholesterol efflux from the explants.
  
  
  CONCLUSIONS
  Adipocyte PLTP plays a small but significant role in plasma PLTP activity and promotes cholesterol efflux from adipose tissues.
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Amirfarbod
authors.initials: A
authors.lastname: Yazdanyar
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Bin
authors.initials: B
authors.lastname: Lou
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Yunqin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Ruohan
authors.initials: R
authors.lastname: Li
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Hai
authors.initials: H
authors.lastname: Hoang Bui
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Ming-Shang
authors.initials: MS
authors.lastname: Kuo
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Mohamad
authors.initials: M
authors.lastname: Navab
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Shucun
authors.initials: S
authors.lastname: Qin
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Li
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
authors.forename: Weijun
authors.initials: W
authors.lastname: Jin
authors.affiliation: From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.). XJiang@downstate.edu.
authors.forename: Xian-Cheng
authors.initials: XC
authors.lastname: Jiang
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D016632:Apolipoprotein A-I / Q000097:blood; D016026:Bone Marrow Transplantation; D002478:Cells, Cultured; D002784:Cholesterol / Q000097:blood; D050556:Fatty Acid-Binding Proteins / Q000235:genetics; D005838:Genotype; D019426:Integrases / Q000235:genetics; D008075:Lipoproteins, HDL / Q000097:blood*; D008264:Macrophages / Q000378:metabolism; D018345:Mice, Knockout; D010641:Phenotype; D049294:Phospholipid Transfer Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010743:Phospholipids / Q000097:blood; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D016632:Apolipoprotein A-I; C493411:Fabp4 protein, mouse; D050556:Fatty Acid-Binding Proteins; D008075:Lipoproteins, HDL; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; C510091:phospholipid transfer protein, mouse; D002784:Cholesterol; C045073:Cre recombinase; D019426:Integrases
keywords: HDL cholesterol; adipocytes; adipose tissue; bone marrow transplantation; cholesterol-efflux regulatory protein; macrophage; phospholipid transfer protein