Bone-resorptive cytokine gene expression in periapical lesions in the rat.
Bone-resorptive cytokine gene expression in periapical lesions in the rat.
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DOI：
10.1111/j.1399-302x.1997.tb00619.x
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发表时间：
1997-04
影响因子：
--
通讯作者：
C. Y. Wang;N. Tani-Ishii;P. Stashenko
中科院分区：
文献类型：
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作者：
C. Y. Wang;N. Tani-Ishii;P. Stashenko
根尖周骨破坏是牙髓感染的重要后遗症。本实验室的最新发现表明，大鼠根尖周病变提取物中的大多数骨吸收活性可以被抗白细胞介素1α抗血清中和。为了进一步阐明其发病机制，我们分析了骨吸收细胞因子信使RNA(MRNAs)在大鼠牙周病变中的表达。对20只SD大鼠的磨牙进行手术暴露，并保持敞开，以允许从口腔环境感染。分别于暴露后第3、7、15、30天从根尖周肉芽肿组织中提取细胞总RNA。逆转录-聚合酶链式反应扩增IL-1α、IL-1β和肿瘤坏死因子-α的mRNA，并与看家基因磷酸甘油醛脱氢酶平行扩增的水平接近。IL-1α和TNF-αmRNA从第7天开始高表达，第15天开始增加，第30天有所下降。相反，IL-1βmRNA的表达水平要低得多，但具有相似的动力学。定量核糖核酸酶保护实验证实了稳态IL-1α和TNF-αmRNA水平的动态变化，但不能检测到IL-1βmRNA的表达。通过原位杂交鉴定IL-1αmRNA表达的细胞，包括浸润性巨噬细胞、常驻成纤维细胞、内皮细胞和破骨细胞。这些结果表明，IL-1α和TNF-α基因在大鼠发展中的根尖周病变中高度表达，并在该模型中从蛋白质水平证实了先前的研究。
Periapical bone destruction is an important pathogenic sequela of pulpal infection. Recent findings from this laboratory have demonstrated that most bone-resorbing activity in extracts of rat periapical lesions can be neutralized by an anti-interleukin (IL)-1 alpha antiserum. To further clarify pathogenic mechanisms, bone-resorptive cytokine messenger RNA (mRNA) expression was analyzed in developing rat periapical lesions. The molar teeth of 20 Sprague-Dawley rats were surgically exposed and left open to permit infection from the oral environment. Total cell RNA was isolated from periapical granuloma tissue obtained on days 3, 7, 15 and 30 after exposure. mRNA for IL-1 alpha, IL-1 beta and tumor necrosis factor alpha (TNF-alpha) was amplified by reverse transcription polymerase chain reaction, and levels were approximated by comparison to the parallel amplification of the housekeeping gene glyceraldehyde phosphate dehydrogenase. IL-1 alpha and TNF-alpha mRNA were both highly expressed beginning on day 7, increased on day 15, and declined somewhat on day 30. In contrast, IL-1 beta mRNA was expressed at much lower levels, but with similar kinetics. The kinetics of steady state IL-1 alpha and TNF-alpha mRNA levels were confirmed using the quantitative RNase protection assay, whereas IL-1 beta mRNA could not be detected by this technique. IL-1 alpha mRNA-expressing cells were identified using in situ hybridization and included infiltrating macrophages, as well as resident fibroblasts, endothelial cells and osteoclasts. These results demonstrate that the IL-1 alpha and TNF-alpha genes are highly expressed in developing periapical lesions in the rat and confirm previous studies at the protein level in this model.