Liu Shih-Ping, Shibu Marthandam Asokan, Tsai Fuu-Jen, Hsu Yuan-Man, Tsai Chang-Hai, Chung Jing-Gung, Yang Jai-Sing, Tang Chih-Hsin, Wang Shulin, Li Qiaowen, Huang Chih-Yang
1Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.
2College of Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Tzu Chi University, Hualien, Taiwan.
Nutr Metab (Lond). 2020 Jan 31;17:12. doi: 10.1186/s12986-020-0432-x. eCollection 2020.
Diabetic patients are highly vulnerable to hypoxic injury, which is associated with hypoxia induced BNIP3 expression that subsequently activate apoptosis. Our previous research show that Tetramethylpyrazine (TMP), a food flavoring agent, represses the hypoxia induced BNIP3 expression attenuate myocardial apoptosis. In this study, we evaluate the effect of TMP to provide protection against hypoxia aggravated high-glucose associated cellular apoptosis.
The cytoprotective effect of TMP against high glucose induced cellular damages was determined on embryo derived H9c2 cardiomyoblast cells that were subjected to 5% hypoxia for 24 h and subjected to different duration of 33 mM high glucose challenge. Further, the involvement of HIF-1α and BNIP3 in cellular damage and the mechanism of protection of TMP were determined by overexpression and silencing HIF-1α and BNIP3 protein expression.
The results show that hypoxic effects on cell viability aggravates with high glucose challenge and this augmentative effect is mediated through BNIP3 in H9c2 cardiomyoblast cells. However, TMP administration effectively reversed the augmented HIF-1α levels and BNIP3 elevation. TMP improved the survival of H9c2 cells and effectively suppressed apoptosis in H9c2 cells. Further comparison on the effects of TMP on H9c2 cells challenged with high glucose and those challenged with hypoxia show that TMP precisely regulated the hypoxic intensified apoptotic effects in high-glucose condition.
The results clearly show that flavoring agent-TMP attenuates cytotoxicity amplified by hypoxia challenge in high glucose condition by destabilizing HIF-1α.
糖尿病患者极易受到缺氧损伤，这与缺氧诱导的BNIP3表达相关，进而激活细胞凋亡。我们之前的研究表明，食品调味剂川芎嗪（TMP）可抑制缺氧诱导的BNIP3表达，减轻心肌细胞凋亡。在本研究中，我们评估TMP对缺氧加重的高糖相关细胞凋亡的保护作用。
在胚胎来源的H9c2心肌母细胞上测定TMP对高糖诱导的细胞损伤的细胞保护作用，这些细胞在5%缺氧条件下处理24小时，并接受不同时长的33 mM高糖刺激。此外，通过过表达和沉默HIF-1α和BNIP3蛋白表达，确定HIF-1α和BNIP3在细胞损伤中的作用以及TMP的保护机制。
结果表明，在H9c2心肌母细胞中，缺氧对细胞活力的影响会因高糖刺激而加剧，且这种增强作用是通过BNIP3介导的。然而，给予TMP可有效逆转HIF-1α水平的升高和BNIP3的上调。TMP提高了H9c2细胞的存活率，并有效抑制了H9c2细胞的凋亡。进一步比较TMP对高糖刺激的H9c2细胞和缺氧刺激的H9c2细胞的影响表明，TMP精确调节了高糖条件下缺氧加剧的凋亡作用。
结果清楚地表明，调味剂TMP通过使HIF-1α失稳，减轻了高糖条件下缺氧刺激放大的细胞毒性。
