LPS-induced IL-6, IL-8, VCAM-1, and ICAM-1 expression in human lymphatic endothelium

Y Sawa, T Ueki, M Hata, K Iwasawa… - … of Histochemistry & …, 2008 - journals.sagepub.com
Y Sawa, T Ueki, M Hata, K Iwasawa, E Tsuruga, H Kojima, H Ishikawa, S Yoshida
Journal of Histochemistry & Cytochemistry, 2008journals.sagepub.com
We have previously reported the TLR4 expression inhuman intestinal lymphatic vessels. In
the study here, microarray analysis showed the expression of the TLR4, MD-2, CD14,
MyD88, TIRAP, TRAM, IRAK1, and TRAF6 genes in cultured human neonatal dermal
lymphatic microvascular endothelial cells (LEC). The microarray analysis also showed that
LEC expressed genes of IL-6, IL-8, VCAM-1, and ICAM-1, and the real-time quantitative
PCR analysis showed that mRNA production was increased by lipopolysaccharide (LPS) …
We have previously reported the TLR4 expression inhuman intestinal lymphatic vessels. In the study here, microarray analysis showed the expression of the TLR4, MD-2, CD14, MyD88, TIRAP, TRAM, IRAK1, and TRAF6 genes in cultured human neonatal dermal lymphatic microvascular endothelial cells (LEC). The microarray analysis also showed that LEC expressed genes of IL-6, IL-8, VCAM-1, and ICAM-1, and the real-time quantitative PCR analysis showed that mRNA production was increased by lipopolysaccharide (LPS). The LPS-induced IL-6, IL-8, VCAM-1, and ICAM-1 production in LEC was suppressed by the introduction of TLR4-specific small interfering RNA, and also by anti-TLR4, nobiletin, and CAPE pretreatment. These findings suggest that LEC has TLR4-mediated LPS recognition mechanisms that involve at least activation of NF-κB, resulting in increased expression of IL-6, IL-8, VCAM-1, and ICAM-1. Both the LPS effect on the gene expression and also the suppression by nobiletin and CAPE pre-treatment on the protein production were larger in IL-6 and in VCAM-1 than in IL-8 and in ICAM-1 in LEC. The signal transduction of NF-κB and AP-1-dependent pathway may be more critical for the expression of IL-6 and VCAM-1 than that of IL-8 and ICAM-1 in LEC.
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