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Effect of 1,25‐dihydroxyvitamin D 3 on induction of scavenger receptor and differentiation of 12‐ O ‐tetradecanoylphorbol‐13‐acetate‐treated THP‐1 human monocyte like cells
Author(s) -
Suematsu Yuji,
Nishizawa Yoshiki,
Shioi Atsushi,
Hino Masayuki,
Tahara Hideki,
Inaba Masaaki,
Morii Hirotoshi,
Otani Shuzo
Publication year - 1995
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041650313
Subject(s) - scavenger receptor , thp1 cell line , receptor , monocyte , chemistry , microbiology and biotechnology , macrophage , cell culture , biochemistry , in vitro , lipoprotein , cholesterol , biology , immunology , genetics
Abstract We investigated the effect of 1,25‐dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ) on the expression of scavenger receptors in human monocytic cell line (THP‐1 cells) treated for 24 h with 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) which induces their differentiation into macrophages. The capacity to degrade 125 I‐labeled acetyl low density lipoprotein (LDL) was developed in accordance with macrophage differentiation. The treatment with 10 nM 1,25(OH) 2 D 3 for 72 h inhibited the degradation of acetyl LDL by THP‐1 macrophages in a dose‐dependent manner, suggesting that 1,25(OH) 2 D 3 inhibits scavenging function in macrophages. In order to clarify the mechanism of its inhibitory effect on degradation of acetyl LDL, we performed the ligand binding assay using 125 I‐labeled acetyl LDL. Scatchard analysis revealed that 1,25(OH) 2 D 3 decreased the number of scavenger receptors without changing the affinity for acetyl LDL. We next examined the effect of 1,25(OH) 2 D 3 on the expression of scavenger receptor mRNA. The mRNA of type I scavenger receptor was first detected in THP‐1 cells 4 days after the treatment with TPA, the mRNA level increased up to 6 days, and then decreased. The treatment with 1,25(OH) 2 D 3 for 72 h dramatically decreased the mRNA levels after the acquisition of macrophage phenotypes as evidenced by nonspecific esterase staining. However, 1,25(OH) 2 D 3 did not affect the activity of non‐specific esterase nor the induction of interleukin‐1β mRNA by lipopolysaccharide in THP‐1 macrophages. These findings suggest that 1,25(OH) 2 D 3 exclusively decreases the expression of scavenger receptors in TPA‐induced THP‐1 macrophages without affecting the basic cellular functions as macrophages. © 1995 Wiley‐Liss Inc.