title: Gene expression analyses of human macrophage phagocytizing sub-micro titanium particles by allergy DNA chip (Genopal).
abstract: The purpose of this study was to examine gene expressions of macrophage phagocytizing sub-micro Ti particles by a DNA chip. Human monocytic cell line THP-1 was differentiated into macrophages by culturing for two days in medium supplemented with 200 nM phorbol ester (PMA). The macrophages were then cultured in four media: medium without PMA (control); medium with suspended sub-micro Ti particles (0.5 wt%); medium with 1.0 microg/ml lipopolysaccharide (LPS); and medium with LPS and Ti particles. After 6 hours' culture, total RNA were extracted and gene expressions were evaluated by DNA allergy chip with 205 allergy and inflammation related gene spots. We found that phagocytosis of sub-micro Ti particles and LPS independently and synergistically up-regulated 17 inflammation-related genes more than two-fold. The extensive expressions of four genes (CCL1, IL1B, IL6 and IL8) were further confirmed by real-time quantitative PCR. It turned out that dual stimulation of LPS and Ti particles most up-regulated three genes (IL1B, IL6 and IL8), followed by LPS while Ti particles moderately but least increased, suggesting that phagocytosis of sub-micro Ti particles induces moderate inflammation with its degree less than LPS, but phagocytosis of sub-micro Ti particles has the potential to worsen inflammation caused by LPS-stimulated macrophages.
authors.affiliation: Department of Dental Materials Science and Technology, Iwate Medical University School of Dentistry, Morioka, Japan. mtaira@iwate-med.ac.jp
authors.forename: Masayuki
authors.initials: M
authors.lastname: Taira
authors.forename: Takashi
authors.initials: T
authors.lastname: Nezu
authors.forename: Minoru
authors.initials: M
authors.lastname: Sasaki
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Kimura
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Kagiya
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Harada
authors.forename: Takayuki
authors.initials: T
authors.lastname: Narushima
authors.forename: Yoshima
authors.initials: Y
authors.lastname: Araki
mesh_terms: D001681:Biological Assay / Q000379:methods*; D002478:Cells, Cultured; D016207:Cytokines / Q000032:analysis / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D008264:Macrophages / Q000502:physiology*; D053758:Nanoparticles; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010587:Phagocytosis / Q000502:physiology*; D014025:Titanium
chemical_list: D016207:Cytokines; D014025:Titanium