title: Chylomicron remnants stimulate release of interleukin-1beta by THP-1 cells.
abstract: Recent findings suggest that the oxidative modification of low-density lipoproteins (LDL) and an increase in triglyceride-rich lipoprotein particles including chylomicron remnants contribute to the progression of atherosclerosis, as does the inflammatory response. We therefore examined whether and how these lipoproteins affected interleukin (IL)-1beta release and mRNA expression for IL-1beta and IL-18 in THP-1 cells, a human monocyte cell line. Chylomicron remnants increased IL-1beta release into the conditioned medium by THP-1 in a dose- and time-dependent manner. At concentrations up to 1 microg/ml, chylomicron remnants increased IL-1beta release by 4-fold compared with the control. Neither native LDL nor oxidized LDL (OxLDL) significantly increased IL-1beta release. Chylomicron remnants increased IL-1beta mRNA expression by 3 times. Native LDL or OxLDL did not increase IL-1beta mRNA, while neither these lipoproteins nor chylomicron remnants increased IL-18 mRNA. Chylomicron remnants also increased the activities of caspase-1 and nuclear factor (NF)-kappaB significantly, while native LDL or OxLDL did not. In conclusion, chylomicron remnants stimulated IL-1beta mRNA expression and IL-1beta protein production probably via caspase-1 and NF-kappaB activation in THP-1 cells.
authors.affiliation: Department of Internal Medicine, Division of Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okumura
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Fujioka
authors.forename: Shinji
authors.initials: S
authors.lastname: Morimoto
authors.forename: Miho
authors.initials: M
authors.lastname: Masai
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sakoda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsujino
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Kashiwamura
authors.forename: Haruki
authors.initials: H
authors.lastname: Okamura
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Ohyanagi
mesh_terms: D015152:Blotting, Northern; D045744:Cell Line, Tumor; D053298:Chylomicron Remnants; D002914:Chylomicrons / Q000494:pharmacology*; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics*; D007951:Leukemia, Myeloid / Q000378:metabolism* / Q000473:pathology; D008074:Lipoproteins / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D053298:Chylomicron Remnants; D002914:Chylomicrons; D007375:Interleukin-1; D008074:Lipoproteins; D012333:RNA, Messenger