各種不同之兒茶素成份，對於出自鼠的腹腔之巨噬細胞和名為J774.1巨噬細胞系的IL-12p40生成作用之影響

Effect of Various Catechins on the IL-12p40 Production by Murine Peritoneal Macrophages and a Macrophage Cell Line, J774.1

劉紹毅 ； Daiju Ichikawa ； Ayako Matsui ； Miwa Imai ； Yoshiko Sonoda ； Tadashi Kasahara

《中華民國血液淨化醫學會雜誌》 14卷3-4期 (2009/12) Pp. 99-101

https://doi.org/10.30024/JFBPS.200912.0026

摘要

Interleukin-12(IL-12)，為一種異二位之抗體細胞激素(Heterodimeric cytokine)，由p40與p35兩個蛋白質次單位(subunit)來組成，主要由monocytes與macrophages所製造，其為調節第一型輔助性T細胞(Th-1 cell)分化作用，不可或缺之角色。綠茶多酚(green tea polyphenol)藉由對細胞激素產生(cytokine production)之調節能力而具有強力之抗氧化及抗發炎作用力。我們藉使用細菌的脂多醣(Lipopolysaccharide, LPS)來誘發鼠的巨噬細胞(murine macrophages)，對於兒茶素(catechins)產生IL-12p40之影響。我們先以各種不同兒茶素的劑量，由0.3~30 μM 之EGCG，來處理鼠的腹腔滲出液細胞(murine peritoneal exudate cells, PEC)與1744.1之巨噬細胞系。我們發現兒茶素對此兩種細胞生成之IL-12p40，有依賴劑量方式(dose-dependent manner)之抑制作用。IL-20p40之蛋白質濃度(protein level)之減少，主要是出自IL-12p40 mRNA之轉錄作用(transcription)，向下調節所造成。這麼多種不同之兒茶素中，EGCG為最強力之抑制劑（抑制IL-12p40），其次為(-)-gallocatechin gallate(GCG)，和(-)-epicatechin gallate (ECG)。EGCG可以抑制p38-MAPK(p38-mitogen-activated protein kinase)之磷酸化作用，但對於JNK(Jun-N-termiral kinase)之磷酸化作用則無影響，這是由於EGCG會加強LPS-誘發之有關細胞外激晦ERK p44/p42(extracellular sigual-related kinase)之磷酸化作用。除此之外，包括EGCG與GCG均可抑制LPS-誘發之IkB-α之分解作用並同步地抑制核蛋白(nuclear protein)與NFkB位置(site)之鍵結和抑制IRF-1之合成作用。這些結果指出，化學結構上含有gallate之兒茶素，特別是EGCG，其在鼠之巨噬細胞(murime macrophages)中，藉由對p44/p42 ERK之增進與對p38 MAPK之抑制，而可將LPS-誘發之IL-12p40生成作用抑制，因而可導致IkBα分解作用與NFkB活化作用之抑制。（按ERK pathway為p38 MAPK pathway 之上游路徑）。

並列摘要

Interleukin-12 (IL-12) is a heterodimeric cytokine comprising p40 and p35 subunits produced mainly by monocytes and macrophages, and plays an essential role in the regulation of the differentiation of Th1 cells. Green tea polyphenols exhibit potent anti-oxidative activities and anti-inflammatory effects by modulating cytokine production. We investigated the effect of catechins on IL-12p40 production in murine macrophages induced by bacterial lipopolysaccharide (LPS). Pretreatment with several catechins at doses of 0.3-30μM suppressed IL-12 p40 production by murine peritoneal exudate cells (PEC) and 1774.1 cells in a dose-dependent manner. Decreases in protein production were primarily due to down-regulation of the transcription of IL-12p40 mRNA. Of the various catechins, (-)-epigallocatechin gallate (EGCG) was the most potent inhibitor, followed by (-)-gallocatechin gallate (GCG) and (-)-epicatechin gallate (ECG). EGCG inhibited LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), but not Jun N-terminal kinase (JNK), while EGCG augmented LPS-induced phosphorylation of p44/p42 extracellular signal-related kinase (ERK). In addition, both EGCG and GCG inhibited LPS-induced degradation of IκBα with concomitant inhibition of nuclear protein binding to NF-κB site and synthesis of IRF-1. These results suggest that gallate-containing catechins, particularly EGCG, inhibits LPS-induced IL-12p40 production in murine macrophages by inhibiting p38 MAPK while enhancing p44/p42 ERK, leading to the inhibition of 1κß xdegradation and NF-κB activation.

並列關鍵字

interleukin-12 IL-12 ； catechin ； - -epigallocatechin gallate EGCG ； NF-κB ； p38MAP kinase ； extracellular signal-related kinase ERK