IKKα/CHUK regulates extracellular matrix remodeling independent of its kinase activity to facilitate articular chondrocyte differentiation.
IKKα/CHUK regulates extracellular matrix remodeling independent of its kinase activity to facilitate articular chondrocyte differentiation.
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DOI：
10.1371/journal.pone.0073024
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Marcu KB
中科院分区：
文献类型：
--
作者：
Olivotto E;Otero M;Astolfi A;Platano D;Facchini A;Pagani S;Flamigni F;Facchini A;Goldring MB;Borzì RM;Marcu KB
非经典NF-κB激活激酶IKKα由CHUK（conserved-helix-loop-helix-ubiquitous-kinase）编码，已报道调节促炎或抗炎反应、细胞存活和细胞分化。在这里，我们研究了IKKα作为人和小鼠软骨细胞细胞外基质（ECM）稳态和向肥大分化的新型效应物的作用机制。分别通过逆转录病毒介导的稳定shRNA转导和Cre重组酶依赖性Lox P位点重组，在原代人骨关节炎（OA）软骨细胞和来自IKKαf/f：CreERT 2小鼠的未成熟小鼠关节软骨细胞（iMAC）中消除IKKα表达。通过mRNA表达谱分析、定量RT-PCR分析、免疫组化和免疫印迹分析，确定MMP-10是软骨细胞中IKKα的主要靶点。通过II型胶原（COL 2）沉积和MMP依赖性COL 2降解产物的缺乏评估ECM完整性，IKKα消融增强了小鼠的ECM完整性。MMP-13和总胶原酶活性显著降低，而TIMP-3（金属蛋白酶组织抑制剂-3）蛋白水平在IKKα缺陷的软骨细胞中增加。IKKα缺陷抑制软骨细胞分化，如茜素红染色的定量抑制和多种软骨细胞分化效应物（包括Runx 2、Col 10a 1和Vegfa）的表达减少所示。重要的是，IKKα缺陷软骨细胞的分化被激酶死亡的IKKα蛋白突变体拯救。IKKα的作用不依赖于其激酶活性，以帮助驱动软骨细胞向肥大样状态分化。IKKα通过多个下游靶点（分别包括mRNA和转录后水平的MMP-10和TIMP-3）积极调节ECM重塑，以维持最大MMP-13活性，这是ECM重塑导致软骨细胞分化所必需的。软骨细胞是关节软骨中独特的细胞成分，其在组织稳态期间处于静止状态并维持ECM的完整性。在OA中，软骨细胞重新获得增殖和分化的能力，并且它们的活化导致明显的软骨退化。因此，我们的发现对于定义OA疾病的发作和/或进展也具有潜在的相关性。
The non-canonical NF-κB activating kinase IKKα, encoded by CHUK (conserved-helix-loop-helix-ubiquitous-kinase), has been reported to modulate pro- or anti- inflammatory responses, cellular survival and cellular differentiation. Here, we have investigated the mechanism of action of IKKα as a novel effector of human and murine chondrocyte extracellular matrix (ECM) homeostasis and differentiation towards hypertrophy. IKKα expression was ablated in primary human osteoarthritic (OA) chondrocytes and in immature murine articular chondrocytes (iMACs) derived from IKKαf/f:CreERT2 mice by retroviral-mediated stable shRNA transduction and Cre recombinase-dependent Lox P site recombination, respectively. MMP-10 was identified as a major target of IKKα in chondrocytes by mRNA profiling, quantitative RT-PCR analysis, immunohistochemistry and immunoblotting. ECM integrity, as assessed by type II collagen (COL2) deposition and the lack of MMP-dependent COL2 degradation products, was enhanced by IKKα ablation in mice. MMP-13 and total collagenase activities were significantly reduced, while TIMP-3 (tissue inhibitor of metalloproteinase-3) protein levels were enhanced in IKKα-deficient chondrocytes. IKKα deficiency suppressed chondrocyte differentiation, as shown by the quantitative inhibition of.Alizarin red staining and the reduced expression of multiple chondrocyte differentiation effectors, including Runx2, Col10a1 and Vegfa,. Importantly, the differentiation of IKKα-deficient chondrocytes was rescued by a kinase-dead IKKα protein mutant. IKKα acts independent of its kinase activity to help drive chondrocyte differentiation towards a hypertrophic-like state. IKKα positively modulates ECM remodeling via multiple downstream targets (including MMP-10 and TIMP-3 at the mRNA and post-transcriptional levels, respectively) to maintain maximal MMP-13 activity, which is required for ECM remodeling leading to chondrocyte differentiation. Chondrocytes are the unique cell component in articular cartilage, which are quiescent and maintain ECM integrity during tissue homeostasis. In OA, chondrocytes reacquire the capacity to proliferate and differentiate and their activation results in pronounced cartilage degeneration. Τηυσ, our findings are also of potential relevance for defining the onset and/or progression of OA disease.
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影响因子：
5.6
作者：
Bobick, Brent E.;Thornhill, Tasha M.;Kulyk, William M.
通讯作者：
Kulyk, William M.
影响因子：
64.8
作者：
Anest, V;Hanson, JL;Baldwin, AS
通讯作者：
Baldwin, AS
影响因子：
3.1
作者：
Goldring MB;Otero M;Plumb DA;Dragomir C;Favero M;El Hachem K;Hashimoto K;Roach HI;Olivotto E;Borzì RM;Marcu KB
通讯作者：
Marcu KB
DOI：
10.1097/01.blo.0000143838.53434.b8
发表时间：
2004-10-01
影响因子：
4.2
作者：
Aigner, T;Bartnik, E;Zimmer, R
通讯作者：
Zimmer, R
影响因子：
--
作者：
Barksby, H. E.;Milner, J. M.;Rowan, A. D.
通讯作者：
Rowan, A. D.