School of Pharmacy and Bioengineering, University of Keele, Newcastle Under Lyme, Staffordshire ST5 5BG, UK.
College of Pharmacy, University of Mosul, Mosul 41002, Iraq.
Biomolecules. 2022 Apr 3;12(4):541. doi: 10.3390/biom12040541.
Cells respond to reduced oxygen availability predominately by activation of the hypoxia-inducible factor (HIF) pathway. HIF activation upregulates hundreds of genes that help cells survive in the reduced oxygen environment. The aim of this study is to determine whether chemical-induced HIF accumulation mimics all aspects of the hypoxic response of cells. We compared the effects of dimethyloxalylglycine (DMOG) (a HIF stabiliser) on PC12 cells cultured in air oxygen (20.9% O AO) with those cultured in either intermittent 20.9% O to 2% O (IH) or constant 2% O (CN). Cell viability, cell cycle, HIF accumulation, reactive oxygen species (ROS) formation, mitochondrial function and differentiation were used to characterise the PC12 cells and evaluate the impact of DMOG. IH and CN culture reduced the increase in cell numbers after 72 and 96 h and MTT activity after 48 h compared to AO culture. Further, DMOG supplementation in AO induced a dose-dependent reduction in the increase in PC12 cell numbers and MTT activity. IH-cultured PC12 cells displayed increased and sustained HIF-1 expression over 96 h. This was accompanied by increased ROS and mitochondrial burden. PC12 cells in CN displayed little changes in HIF-1 expression or ROS levels. DMOG (0.1 mM) supplementation resulted in an IH-like HIF-1 profile. The mitochondrial burden and action potential of DMOG-supplemented PC12 cells did not mirror those seen in other conditions. DMOG significantly increased S phase cell populations after 72 and 96 h. No significant effect on PC12 cell differentiation was noted with IH and CN culture without induction by nerve growth factor (NGF), while DMOG significantly increased PC12 cell differentiation with and without NGF. In conclusion, DMOG and reduced oxygen levels stabilise HIF and affect mitochondrial activity and cell behaviour. However, DMOG does not provide an accurate replication of the reduced oxygen environments.
细胞主要通过激活缺氧诱导因子（HIF）通路来应对氧含量降低。HIF 的激活会上调数百个基因，帮助细胞在低氧环境中存活。本研究旨在确定化学诱导的 HIF 积累是否模拟了细胞缺氧反应的所有方面。我们比较了二甲草酰基甘氨酸（DMOG）（一种 HIF 稳定剂）对在空气中氧气（20.9% O AO）中培养的 PC12 细胞与在间歇性 20.9% O 到 2% O（IH）或恒常 2% O（CN）中培养的 PC12 细胞的影响。细胞活力、细胞周期、HIF 积累、活性氧（ROS）形成、线粒体功能和分化用于描述 PC12 细胞，并评估 DMOG 的影响。与 AO 培养相比，IH 和 CN 培养使 72 和 96 小时后细胞数量的增加和 48 小时后 MTT 活性降低。此外，在 AO 中补充 DMOG 会导致 PC12 细胞数量和 MTT 活性增加的剂量依赖性降低。IH 培养的 PC12 细胞在 96 小时内持续增加和维持 HIF-1 表达。这伴随着 ROS 和线粒体负担的增加。CN 培养的 PC12 细胞中 HIF-1 表达或 ROS 水平几乎没有变化。DMOG（0.1 mM）补充导致类似于 IH 的 HIF-1 谱。补充 DMOG 的 PC12 细胞的线粒体负担和动作电位与其他条件下观察到的情况不相似。DMOG 在 72 和 96 小时后显著增加 S 期细胞群体。在没有神经生长因子（NGF）诱导的情况下，IH 和 CN 培养对 PC12 细胞分化没有显著影响，而 DMOG 显著增加了有无 NGF 的 PC12 细胞分化。总之，DMOG 和低氧水平稳定了 HIF，并影响了线粒体活性和细胞行为。然而，DMOG 并没有提供对低氧环境的准确复制。
