Cytokine-induced MMP13 Expression in Human Chondrocytes Is Dependent on Activating Transcription Factor 3 (ATF3) Regulation
Cytokine-induced MMP13 Expression in Human Chondrocytes Is Dependent on Activating Transcription Factor 3 (ATF3) Regulation
复制标题
DOI：
10.1074/jbc.m116.756601
复制
发表时间：
2017-02-03
影响因子：
4.8
通讯作者：
Rowan, Andrew D.
中科院分区：
文献类型：
--
作者：
Chan, Chun Ming;Macdonald, Christopher D.;Rowan, Andrew D.
胶原酶基质金属蛋白酶13 （MMP13）对软骨细胞外基质（ECM）的不可逆破坏是骨关节炎（OA）进展中的一个关键事件。虽然炎症最常与炎症性关节疾病相关，但它也发生在OA中，因此与普遍的组织破坏有关。在这里，炎症产生cFOS AP-1早期反应，间接影响MMP13基因表达。为了确定cFOS对MMP13长期产生的更直接影响，我们研究了在cFOS快速、短暂表达和随后的MMP13诱导之间发生的潜在分子事件。重要的是，我们发现MMP13 mRNA的表达是由新生hnRNA转录反映的。通过ChIP检测，cFOS向MMP13启动子的募集发生在基因转录之前的早期阶段，并且转录起始标记的募集也与MMP13表达相关。此外，早期FOS表达后的蛋白合成抑制导致MMP13表达显著降低，这表明不同的调节因子调节了该基因的表达。随后的mRNA转录组分析强调了FOS后不久诱导的几个基因可能有助于MMP13的表达。特异性小干扰rna介导的沉默表明，ATF3对MMP13具有与cFOS一样高的选择性。此外，ATF3的表达依赖于AP-1(cFOS/cJUN)，并且在早期短暂的cFOS反应后维持表达水平。此外，ATF3在不再支持FOS结合的时间点上结合受刺激软骨细胞的近端MMP13 AP-1基序。因此，这些发现支持cFOS（间接）和ATF3（直接）在影响人软骨细胞中MMP13转录中的作用。
Irreversible breakdown of cartilage extracellular matrix (ECM) by the collagenase matrix metalloproteinase 13 (MMP13) represents a key event in osteoarthritis (OA) progression. Although inflammation is most commonly associated with inflammatory joint diseases, it also occurs in OA and is thus relevant to the prevalent tissue destruction. Here, inflammation generates a cFOS AP-1 early response that indirectly affects MMP13 gene expression. To ascertain a more direct effect on prolonged MMP13 production we examined the potential molecular events occurring between the rapid, transient expression of cFOS and the subsequent MMP13 induction. Importantly, we show MMP13 mRNA expression is mirrored by nascent hnRNA transcription. Employing ChIP assays, cFOS recruitment to the MMP13 promoter occurs at an early stage prior to gene transcription and that recruitment of transcriptional initiation markers also correlated with MMP13 expression. Moreover, protein synthesis inhibition following early FOS expression resulted in a significant decrease in MMP13 expression thus indicating a role for different regulatory factors modulating expression of the gene. Subsequent mRNA transcriptome analyses highlighted several genes induced soon after FOS that could contribute to MMP13 expression. Specific small interfering RNA-mediated silencing highlighted that ATF3 was as highly selective for MMP13 as cFOS. Moreover, ATF3 expression was AP-1(cFOS/cJUN)-dependent and expression levels were maintained after the early transient cFOS response. Furthermore, ATF3 bound the proximal MMP13 AP-1 motif in stimulated chondrocytes at time points that no longer supported binding of FOS. Consequently, these findings support roles for both cFOS (indirect) and ATF3 (direct) in effecting MMP13 transcription in human chondrocytes.