title: The Effects of Phellinus linteus Polysaccharide Extracts on Cholesterol Efflux in Oxidized Low-Density Lipoprotein-Loaded THP-1 Macrophages.
abstract: The removal of excess cellular cholesterol is critical for maintaining cellular cholesterol homeostasis. Phellinus linteus polysaccharide extracts (PLPEs) is an immunomudulatory agent with a molecular weight of 153 kd. Here, we analyzed the effects of PLPEs on cholesterol efflux in oxidized low-density lipoprotein (ox-LDL)-loaded THP-1 (human acute monocytic leukemia cell line) macrophages. Various concentrations of PLPEs (5, 10, 20, and 100 μg/mL) were used to treat cells. Cholesterol efflux analysis was performed to analyze the cholesterol efflux ratio in PLPE-treated cells. Semiquantitative reverse transcription-polymerase chain reaction and Western blot analysis were conducted to assess the expression of target genes. Low dose of PLPEs (5-20 μg/mL) dose dependently enhanced cholesterol efflux to apolipoprotein A-I (ApoA-I), evidenced by promoting the expression of adenosine 5'-triphosphate (ATP)-binding cassette A1, ATP-binding cassette G1, and peroxisome proliferation-activated receptor γ, key regulators for cholesterol efflux. Moreover, GW9662, a potent antagonist of peroxisome proliferation-activated receptor γ, inhibited PLPE (20 μg/mL)-promoted cholesterol efflux to ApoA-I in a dose-dependent fashion. However, high dose of PLPEs (100 μg/mL) inhibited cholesterol efflux to ApoA-I from ox-LDL-loaded THP-1 macrophages, enhanced the production of superoxide anion, decreased mitochondrial membrane potential and ATP levels, and raised nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate oxidase subunits. Thus, these results indicate that low and high doses of PLPEs exhibit opposite effects on cholesterol efflux from ox-LDL-loaded THP-1 cells.
authors.affiliation: From the *Department of Cardiovascular Surgery ICU, Henan Provincial People's Hospital, Zhengzhou; †Department of Radiology, Puyang City Oil-Field General Hospital, Puyang; and ‡Department of Rehabilitation Medicine, Henan Provincial People's Hospital; and §Department of Respiratory, The First Affiliated Hospital of Zhengzhou University, Henan Province, China.
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Zhao-yun
authors.initials: ZY
authors.lastname: Cheng
authors.forename: Xi-guo
authors.initials: XG
authors.lastname: Cai
authors.forename: Hong-min
authors.initials: HM
authors.lastname: Wang
mesh_terms: D045744:Cell Line, Tumor; D002784:Cholesterol / Q000378:metabolism*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism*; D000084682:Phellinus; D010936:Plant Extracts; D011134:Polysaccharides / Q000494:pharmacology*
chemical_list: D008077:Lipoproteins, LDL; C526145:Phellinus linteus extract; D010936:Plant Extracts; D011134:Polysaccharides; C099252:oxidized low density lipoprotein; D002784:Cholesterol