Effects of hypoxia on anabolic and catabolic gene expression and DNA methylation in OA chondrocytes.
Effects of hypoxia on anabolic and catabolic gene expression and DNA methylation in OA chondrocytes.
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DOI：
10.1186/1471-2474-15-431
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发表时间：
2014-12-15
影响因子：
2.3
通讯作者：
Oreffo RO
中科院分区：
文献类型：
--
作者：
Alvarez K;de Andrés MC;Takahashi A;Oreffo RO
软骨是一种无血管和无神经的组织。软骨细胞在这种低氧张力和营养供应差的受限环境中茁壮成长，这导致人们认为缺氧可能是预防骨关节炎（OA）发展的保护机制。还有越来越多的证据支持表观遗传因素在 OA 发病机制中的作用。然而，很少有研究调查缺氧环境下的表观遗传-OA 过程。目前的研究调查了缺氧对 OA 发病机制中合成代谢和分解代谢基因的基因表达和 DNA 甲基化的影响。从 OA 股骨头中提取的软骨细胞在常氧和缺氧（分别为 20% 和 2% 氧浓度）下孵育。将白细胞介素 1-β (IL-1β) 加制瘤素 M (OSM)、5-氮杂脱氧胞苷 (5-aza-dC) 或单独的培养基（对照）每周两次添加到孵育的样品中。 5 周后，使用基于 SYBR Green 的 qRT-PCR 测量 IX 型胶原蛋白 (COL9A1)、IL1B 和基质金属蛋白酶 13 (MMP13) 基因表达水平，并与焦磷酸测序方法分析的甲基化状态相关联。缺氧导致 COL9A1 和 IL1B 的相对表达分别增加 >50 倍和 >10 倍。这与这些基因的 DNA 甲基化状态呈负相关。对照细胞中 MMP13 的表达在 2% 氧张力下降低。在含氧量正常的条件下，用 IL-1β 和 5-aza-dC 刺激的细胞中 MMP13 的相对表达增加，这种效应在低氧张力下被消除，尽管没有观察到与甲基化状态的相关性。这些发现证明了缺氧在合成代谢和分解代谢基因表达的调节以及 DNA 甲基化变化的影响中的作用。这些结果进一步支持了表观遗传学在 OA 中的作用，更重要的是，强调了软骨细胞的生理环境与骨关节炎过程之间的复杂关系，对治疗干预和我们对 OA 病理生理学的理解具有影响。本文的在线版本 (doi:10.1186/1471-2474-15-431) 包含补充材料，可供授权用户使用。
Cartilage is an avascular and aneural tissue. Chondrocytes thrive in this restricted environment of low oxygen tension and poor nutrient availability which has led to suggestions that hypoxia may be a protective mechanism against the development of osteoarthritis (OA). There is also a growing body of evidence to support the role of epigenetic factors in the pathogenesis of OA. However, few studies have investigated the epigenetic-OA process within a hypoxic environment. The current study has investigated the effects of hypoxia on gene expression and DNA methylation of anabolic and catabolic genes involved in the pathogenesis of OA. Chondrocytes extracted from OA femoral heads were incubated in normoxia and hypoxia (20% and 2% oxygen concentrations respectively). Interleukin 1-beta (IL-1β) plus oncostatin M (OSM), 5-azadeoxycytidine (5-aza-dC) or media alone (control) were added twice weekly to the incubated samples. After 5 weeks, levels of Collagen type IX (COL9A1), IL1B, and matrix metalloproteinase-13 (MMP13) gene expression were measured using SYBR Green-based qRT-PCR and were correlated with methylation status analysed by pyrosequencing methodology. Hypoxia resulted in a >50-fold and >10-fold increase in relative expression of COL9A1 and IL1B respectively. This was inversely correlated to the DNA methylation status of these genes. Expression of MMP13 was reduced at 2% oxygen tension in control cells. Relative expression of MMP13 increased in cells stimulated with IL-1β and 5-aza-dC in normoxic conditions, and this effect was eliminated at low oxygen tension although no correlation with methylation status was observed. These findings demonstrate a role for hypoxia in the regulation of anabolic and catabolic gene expression and the influence of changes in DNA methylation. These results further support the role of epigenetics in OA and, critically, highlight the complex relationship between the physiological environment of cartilaginous cells and the osteoarthritic process with implications for therapeutic intervention and our understanding of OA pathophysiology. The online version of this article (doi:10.1186/1471-2474-15-431) contains supplementary material, which is available to authorized users.
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影响因子：
7
作者：
Grimshaw, MJ;Mason, RM
通讯作者：
Mason, RM
影响因子：
7
作者：
Grimshaw, MJ;Mason, RM
通讯作者：
Mason, RM
影响因子：
--
作者：
Sato, T;Konomi, K;Nakajima, T
通讯作者：
Nakajima, T
影响因子：
--
作者：
Hashimoto, Ko;Oreffo, Richard O. C.;Gibson, Marc B.;Goldring, Mary B.;Roach, Helmtrud I.
通讯作者：
Roach, Helmtrud I.
影响因子：
3.9
作者：
MORALES, TI
通讯作者：
MORALES, TI