Effects of Individual Control of pH and Hypoxia in Chondrocyte Culture
Effects of Individual Control of pH and Hypoxia in Chondrocyte Culture
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DOI：
10.1002/jor.20994
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发表时间：
2010-04-01
影响因子：
2.8
通讯作者：
Jahr, H.
中科院分区：
文献类型：
--
作者：
Das, R. H. J.;van Osch, G. J. V. M.;Jahr, H.
氧张力（pO（2））和pH值对基因和蛋白质表达和人软骨细胞的代谢活性的影响进行了独立评估。软骨细胞在生物反应器中在pH范围（6.4-7.4）和不同pO（2）（5和20%）下培养5天。测定对基因表达、DNA含量、蛋白质表达和代谢活性的影响。线性回归分析表明，I型胶原蛋白（COL 1），S 0X 9和VEGF的基因表达显着降低在酸性pH值，而聚集蛋白聚糖，II型胶原蛋白，和HIF 1A的表达是pH值无关。低pO（2）时VEGF蛋白表达水平较高。酸性pH严重降低了VEGF释放到培养基中、葡萄糖消耗和乳酸盐产生。细胞外pH值比氧张力对细胞功能的影响更强，后者在缺氧条件下表现为COL 1基因表达下调和VEGF蛋白表达上调。低氧培养抑制COL 1 mRNA表达的pH依赖性，而SOX 9的表达在很大程度上是缺氧无关的，但pH依赖性。HIF 1A和VEGF的表达显示了不同的pH依赖性。细胞外pH和氧张力的微妙波动明显影响软骨细胞代谢和标志物表达。复杂的pH值和氧气控制不仅可以研究（病理）生理变化，而且还为软骨组织工程开辟了新的途径。(C)2009骨科研究学会。出版社：Wiley Periodicals，Inc. J Orthop Res 28：537-545，2010
Effects of oxygen tension (pO(2)) and pH on gene and protein expression and metabolic activity of human chondrocytes were independently assessed. Chondrocytes were cultured under a range of pH (6.4-7.4) and different pO(2) (5 and 20%) during 5 days in a bioreactor. Effects on gene expression, DNA content, protein expression, and metabolic activity were determined. Linear regression analysis showed that gene expression of type I collagen (COL1), S0X9, and VEGF is significantly lower at acidic pH, while expression of aggrecan, type II collagen, and HIF1A is pH-independent. Higher protein levels of VEGF were found under low pO(2). Acidic pH severely lowered VEGF release into medium, glucose consumption, and lactate production. Extracellular pH proved to more potently influence cell function than oxygen tension, the latter showing down-regulation of COL1 gene expression and up-regulation of VEGF protein under hypoxia. Hypoxic culture inhibits COL1 mRNA expression pH-dependently, while expression of SOX9 is largely hypoxia independent, but pH dependent. Expression of HIF1A and VEGF revealed divergent pH dependencies. Subtle fluctuations in extracellular pH and oxygen tension clearly influence chondrocyte metabolism and marker expression. Sophisticated pH and oxygen control not only allows study of (patho)physiological changes, but also opens new venues in cartilage tissue engineering. (C) 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:537-545, 2010