Dallot Emmanuelle, Méhats Céline, Oger Stéphanie, Leroy Marie-Josèphe, Breuiller-Fouché Michelle
Institut National de la Santé et de la Recherche Médicale, Inserm U427, Faculté des Sciences Pharmaceutiques et Biologiques, Université René Descartes, 4, avenue de l'Observatoire, 75006 Paris, France.
Biochimie. 2005 Jun;87(6):513-21. doi: 10.1016/j.biochi.2005.02.009. Epub 2005 Mar 19.
Human myometrial cells respond to the endotoxin lipopolysaccharide (LPS) by activation of protein kinase C (PKC) zeta and nuclear translocation of the p65 subunit of NF-kB. Our first objective was to determine the expression of TLR4 in cultured myometrial cells. Positive immunoreactivity observed for TLR4 suggests that myometrial cells have the potential to respond to LPS. To confirm that LPS signals via TLR4, the ability of an anti-TLR4 neutralizing antibody to block LPS-induced translocation of p65 was demonstrated. To determine whether LPS-induced nuclear translocation of p65 is mediated through the PKC pathway, myometrial cells were treated with various inhibitors of the PKC isoforms already characterized in human myometrium. Neither the selective conventional PKC inhibitor nor the inhibitor of PKCdelta affected NF-kB activation. By contrast, we found that treatment of myometrial cells with an antisense against PKCzeta affect LPS-induced nuclear translocation of the p65 subunit of NF-kB. Accordingly, our data support the notion that PKCzeta is essential for LPS-induced NF-kB p65 subunit nuclear translocation in human myometrial cells.
人子宫肌层细胞通过蛋白激酶C（PKC）ζ的激活和核因子κB（NF-κB）p65亚基的核转位来响应内毒素脂多糖（LPS）。我们的首要目标是确定培养的子宫肌层细胞中Toll样受体4（TLR4）的表达。观察到的TLR4阳性免疫反应表明子宫肌层细胞有对LPS作出反应的潜力。为了证实LPS通过TLR4发出信号，证明了抗TLR4中和抗体阻断LPS诱导的p65核转位的能力。为了确定LPS诱导的p65核转位是否通过PKC途径介导，用已在人子宫肌层中鉴定的各种PKC同工型抑制剂处理子宫肌层细胞。选择性传统PKC抑制剂和PKCδ抑制剂均未影响NF-κB的激活。相比之下，我们发现用针对PKCζ的反义寡核苷酸处理子宫肌层细胞会影响LPS诱导的NF-κB p65亚基的核转位。因此，我们的数据支持PKCζ对于人子宫肌层细胞中LPS诱导的NF-κB p65亚基核转位至关重要这一观点。
