Zhang Guolei, Zha Junpu, Liu Junchuan, Di Jun
Department of Orthopaedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China.
Arch Med Sci. 2019 Mar;15(2):475-483. doi: 10.5114/aoms.2018.73520. Epub 2018 Feb 15.
One of the crucial mechanisms following spinal cord injury is mitochondria-associated cell death. Minocycline, an anti-inflammatory drug, is well known to impede mitochondrial cell death. However, there has been no study on the effect of minocycline linking Fas cell surface death receptor (FAS)-mediated cell death and hypoxia inducible factor (HIF-1α), the targets involved in mitochondrial cell death.
Male Sprague Dawley rats ( = 15, divided into three groups) were subjected to traumatic spinal cord injury and were injected with minocycline ( = 5) (90 mg/kg and later a 45 mg/kg dose twice a day (every 12 h)). Injection with sterile PBS in injured animals served as the vehicle ( = 5) and another group comprised healthy animals ( = 5). TUNEL assay was used to quantify cell death. The release of Smac/Diablo, cytochrome-c (cyt-c), HIF-1α, FAS ligand (FASL) and tumour necrosis factor-α (TNF-α) was measured using ELISA. Expression of HIF-1α, FASL and other cell death associated factors was quantified at the mRNA and protein level and confirmed with immunohistochemistry.
There was a marked reduction in the HIF-1α and FASL expression levels in the minocycline-treated group compared to the vehicle. The reduction of HIF-1α and FASL was associated with other factors linked to cell death (Smac/Diablo, cyt-c, TNF-α, p53, caspase-8 and BH3 interacting domain death agonist (BID)) ( < 0.5; * < 0.05 vs. vehicle group, ** < 0.01 vs. vehicle group).
The present study focuses on the investigation of minocycline in inhibiting mitochondria-associated cell death by modulating FASL and HIF-1α expression, which are seemingly interlinked mechanisms contributing to cell death.
脊髓损伤后的关键机制之一是线粒体相关的细胞死亡。米诺环素是一种抗炎药物，众所周知它能阻止线粒体细胞死亡。然而，尚未有关于米诺环素对Fas细胞表面死亡受体（FAS）介导的细胞死亡以及缺氧诱导因子（HIF-1α）（线粒体细胞死亡所涉及的靶点）影响的研究。
雄性Sprague Dawley大鼠（n = 15，分为三组）遭受创伤性脊髓损伤，并注射米诺环素（n = 5）（90 mg/kg，随后每天两次（每12小时一次）给予45 mg/kg剂量）。在受伤动物中注射无菌PBS作为对照（n = 5），另一组为健康动物（n = 5）。采用TUNEL检测法对细胞死亡进行定量。使用酶联免疫吸附测定法测量Smac/Diablo、细胞色素c（cyt-c）、HIF-1α、FAS配体（FASL）和肿瘤坏死因子-α（TNF-α）的释放。在mRNA和蛋白质水平对HIF-1α、FASL及其他细胞死亡相关因子的表达进行定量，并通过免疫组织化学进行确认。
与对照组相比，米诺环素治疗组的HIF-1α和FASL表达水平显著降低。HIF-1α和FASL的降低与其他细胞死亡相关因子（Smac/Diablo、cyt-c、TNF-α、p53、半胱天冬酶-8和BH3相互作用结构域死亡激动剂（BID））有关（P < 0.5；*与对照组相比P < 0.05，**与对照组相比P < 0.01）。
本研究聚焦于米诺环素通过调节FASL和HIF-1α表达来抑制线粒体相关细胞死亡的研究，这两种机制似乎相互关联，共同导致细胞死亡。
