ObjectiveTo explore the effects and molecular mechanisms of histone methylase G9a inhibitor BIX-01294 on apoptosis in esophageal squamous cell carcinoma (ESCC).MethodsMTT assay and Colony-forming Units were adopted to determine the effects of BIX-01294 on the growth and proliferation of ESCC cell lines EC109 and KYSE150. Flow cytometry was used to analyze the apoptosis status of ESCC cells after the treatment of BIX-01294. The effects of BIX-01294 treatment on the expressions of G9a catalytic product H3K9me2, DNA double-strand break (DSB) markers, and apoptosis-related proteins were detected by Western blotting.ResultsBIX-01294 inhibited the growth of EC109 and KYSE150 cells in a dose-dependent manner (P<0.05), and BIX-01294 with the inhibitory concentration 50% (IC50) significantly inhibited the formation of colony (P<0.05). After 24 hours treatment of BIX-01294 (IC50), the apoptosis rate of EC109 cells increased from 11.5%±2.1% to 42.5%±5.4%, and KYSE150 cells from 7.5%±0.9% to 49.2%±5.2% (P<0.05). The expression level of the G9a catalytic product, H3K9me2, significantly decreased (P<0.05); while the expression of the DSB marker γH2AX was dramatically enhanced (P<0.05). We also found that the mitochondrial apoptosis pathway was activated and the expression levels of cleaved caspase3 and cleaved PARP were significantly elevated (P<0.05).ConclusionBIX-01294, the inhibitor of methyltransferase G9a, prompted apoptosis in ESCC cells by inducing DSB damage and activating mitochondrial apoptosis pathway.
Optic atrophy,hereditary／diagnosis; Polymerase chain reaction; DNA,mitochondrial; Point mutation; Sequence analysis
Objective To review the research progress of mitochondrial dynamics mediated by optic atrophy 1 (OPA1) in skeletal system diseases. MethodsThe literatures about OPA1-mediated mitochondrial dynamics in recent years were reviewed, and the bioactive ingredients and drugs for the treatment of skeletal system diseases were summarized, which provided a new idea for the treatment of osteoarthritis. Results OPA1 is a key factor involved in mitochondrial dynamics and energetics and in maintaining the stability of the mitochondrial genome. Accumulating evidence indicates that OPA1-mediated mitochondrial dynamics plays an important role in the regulation of skeletal system diseases such as osteoarthritis, osteoporosis, and osteosarcoma. Conclusion OPA1-mediated mitochondrial dynamics provides an important theoretical basis for the prevention and treatment of skeletal system diseases.
摘要:目的: 探讨在血管紧张素Ⅱ(AngⅡ)诱导血管平滑肌细胞(VSMCs)NOX1基因表达增加中线粒体所起的作用。 方法 :体外培养大鼠主动脉VSMCs,用线粒体呼吸链的抑制剂阻断线粒体的作用,用荧光实时定量PCR检测NOX1基因表达的量。 结果 :AngⅡ能够诱导 NOX1基因的表达增加,线粒体呼吸链的抑制剂能够抑制上述这一作用。 结论 :在大鼠的VSMCs中,AngⅡ诱导NOX1的增加通过线粒体呼吸的作用。Abstract: Objective: To detect the role of mitochondria involved in Angiotensin Ⅱ(Ang Ⅱ) induced NOX1 gene expression. Methods :Rat aortic vascellum smooth muscle cells(VSMCs) were cultured in vitro,and were treated with or without some inhibitors of complexs in mitochondrial respiratory chain. Realtime RTPCR was used to calculate the expression of NOX1 mRNA. Results :AngⅡ stimulated NOX1 gene expression,while some inhibitors of complexs in mitochondrial respiratory chain attenuated this progress.〖WTHZ〗Conclusion : Mitochondrial respiratory chain mediates expression of NOX1 gene in VSMCs by AngⅡ.
Objective To investigate the changes in mitochondrial morphology, structure and function in rats with severe intermittent hypoxia, as well as the effects of intermittent hypoxia and its severity on cognitive function. Methods A total of 18 rats were selected to construct a model of severe intermittent hypoxia, which were divided into a normal control group, an intermittent air control group, and a 5% intermittent hypoxia group for 8 weeks, with 6 rats in each group. The structural and functional changes of mitochondria in the hippocampal CA1 region were observed. A total of 30 rats were randomly divided into 5 groups: a normal control group, an intermittent air control group, a 5% intermittent hypoxia 4-week group, a 5% intermittent hypoxia 6-week group, and a 5% intermittent hypoxia 8-week group, with 6 rats in each group. The cognitive function of the rats in each group was evaluated by Morris water maze experiment. Results In the mitochondria of the hippocampal CA1 region of severely intermittent hypoxic rats, bilayer membranes or multilayer membranes were visible, the mitochondria were swollen, cristae were broken and vacuolated, and their respiratory function was significantly weakened, the membrane permeability was increased, and the membrane potential was reduced. In the Morris water maze, there was no significant difference in swimming speed between the rats. With the prolongation of intermittent hypoxia action time, the latency of finding the hidden platform in each group of rats increased significantly, and the residence time of the target quadrant decreased significantly. Conclusions Mitochondrial structure in the hippocampal CA1 region of the rat brain is destroyed during severe intermittent hypoxia, and dysfunction and cognitive impairment occur. With the prolongation of intermittent hypoxic injury, the degree of cognitive impairment worsens.
Objective To investigate the spectrum of mitochondrial DNA (mtDNA) mutations in Chinese patients with Leber′s hereditary optic neuropathy (LHON). Methods The primary mtDNA mutations (G3460A、G11778A and T14484 C) of 140 patients with LHON were detected by mutation-specific priming polymerase chain reaction (MSP-PCR), heteroduplex-single strand conformation polymorphism polymerase chain reaction (HA-SSCP), restriction fragment length polymorphisms (RFLP) and measurement of DNA sequence. The transmissibility of the patients′ stirps was analyzed.Results In the 140 patients with LHON, G11778A mtDNA primary mutation was found in 130 (92.9%), including 113 males and 17 females; G3460A mutation was found in 2 (1.4%) including 1 male and 1 female; G14484A mutation was found in 8 (5.7% ) including 6 males and 2 females.Conclusion In Chinese patients with LHON, the incidence of G11778A mtDNA mutation is higher than that of G3460A and T14484C. (Chin J Ocul Fundus Dis，2003，19：269-332)
Leber hereditary optic neuropathy (LHON) is a matrilineal hereditary optic neuropathy in which mitochondrial DNA mutations lead to retinal ganglion cell degeneration. At present, the treatment for LHON is limited. Early symptomatic treatment and medical treatment may improve the vision of patients. In recent years, rapid progress has been made in gene therapy. Many clinical studies have confirmed its safety and efficacy. Monocular gene therapy is helpful to improve the visual function of LHON patients, and it can also improve the visual acuity of uninjected eyes. Patients do not have serious eye or systemic adverse events during the treatment period, showing good safety and tolerance. Studies with larger sample size and longer follow-up time are needed to further verify the efficacy and safety of gene therapy in the future. Gene therapy is expected to become a safe and effective treatment, bringing hope to LHON patients.
Mitochondrial adenosine triphosphate (ATP) synthase is the key enzyme of mitochondrial oxidative phosphorylation reaction.The down-regulation of the mitochondrial ATP synthase is a hallmark of most human carcinomas, which is the embodiment of the bioenergetic signature of cancer in the performance of the decreased oxidative phosphorylation and increased aerobic glycolysis. Combining with the bioenergetic signature of cancer, studies showed that mitochondrial ATP synthase and multidrug resistance and adverse prognosis of tumor were closely related. Its mechanisms are related to post-transcriptional regulation of the ATP synthase,the hypermethylation of the ATP synthase gene and the inhibitor peptide of the mitochondrial ATP synthase, called ATP synthase inhibitory factor 1(IF1). In this review, we stress the biological characteristics of mitochondrial ATP synthase and the relationship between ATP synthase and multidrug resistance and prognosis of Malignant tumor, in order to find a new way for tumor therapy.
The present study was to investigate the effects of infusing remifentanil-poly-caprolactone (REM-PCL) through the abdominal aorta on spinal cord ischemia reperfusion injury (SCIRI). The model of SCIRI was created by clamping the infrarenal aortic in thirty-six New Zealand white rabbits, which were randomly divided into sham group (group S), control group (group C), and REM-PCL group (group R) with 12 rabbits in each one. The spinal cord microcirculatory blood flow (SCMBF) and blood flow rate (BFR) were monitored before ischemia, 15 min, 30 min, 60 min and 120 min after reperfusion, respectively. Neurologic Function was evaluated before ischemia, 6h, 12h and 24h after reperfusion. The concentration of serum neuron-specific enolase (NSE), interleukin-lβ (IL-lβ) and interleukin-8 (IL-8) were monitored before ischemia, 45 min after ischemia, 30 min, 60 min, 6 h, 12 h and 24 h after reperfusion. The abnormal rate of motor neuron of spinal cord tissues and the level of superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), total anti-oxidation capacity (T-AOC) and mitochondrial swelling degree (MSD) in neural mitochondria were determined before ischemia, 45 min after clamping, 60 min and 120 min after reperfusion. As a result, the neural mitochondrial SOD, GSH-PX and T-AOC decreased while ROS, MDA, MSD, IL-lβ, IL-8 and NSE distinctly increased after clamping of the abdominal aorta as compared to the value before ischemia in group C (P < 0.01). Neurologic function scores recovered more rapidly in group R than those in group C during reperfusion (P < 0.01). The neural mitochondrial SOD, GSH-PX and T-AOC were distinctly higher while ROS, MDA, MSD, IL-lβ, IL-8 and NSE were distinctly lower in group R than those in group C (P < 0.01). The abnormal rate of motor neuron was significantly higher in group C during reperfusion than that in group R (P < 0.01). It has been shown that the intra-aortic REM-PCL infusion can alleviate SCIRI by inhibiting inflammatory response and improving mitochondrial anti-oxidation capacity.
ObjectiveTo investigate the expression of circular RNA mitochondrial fusin 2 (circ-MFN2) in pancreatic cancer and analyze its correlation with clinicopathological features and prognosis.MethodsThe expressions of circ-MFN2 miRNA in 55 cases of pancreatic cancer tissues and serum were detected by qRT-PCR, and analyzed the correlation between circ-MFN2 and clinicopathological factors of pancreatic cancer and prognosis. The sensitivity, specificity and accuracy of expression of circ-MFN2 miRNA in the diagnosis of pancreatic cancer were statistically analyzed. ROC curve was used to analyze its efficacy as a biomarker for early diagnosis of pancreatic cancer.ResultsCompared with paracancerous tissues of pancreatic cancer and serum of healthy control group, circ-MFN2 miRNA was highly expressed in pancreatic cancer tissues and serum, and the difference were all statistically significant (all P<0.05). Chi square test showed that the expression of circ-MFN2 miRNA in pancreatic cancer tissues was not related to age, gender, tumor size, pathological type, and tumor site (P>0.05), but was significantly related to CA19-9 level, TNM stage, tumor differentiation and lymph node metastasis (P<0.05). The sensitivity, specificity and accuracy of expression of circ-MFN2 miRNA for pancreatic cancer were 72.7%, 70.9% and 83.6% respectively, which were all higher than that of CA19-9 (54.5%, 50.9% and 52.7%, P<0.05). Kaplan-Meier analysis showed that the median survival time of pancreatic cancer patients with high expression of circ-MFN2 miRNA was significantly shorter than that of patients with low expression (9.1 months vs 22.3 months, P<0.05). The area under ROC curve of circ-MFN2 miRNA as a serum biomarker for the diagnosis of pancreatic cancer was 0.861 [95%CI (0.775, 1.157), P=0.000]. Cox multivariate analysis showed that the expression of cirC-MFN2 miRNA and lymph node metastasis were independent risk factors for the prognosis of pancreatic cancer patients.ConclusionsCirc-MFN2 miRNA is highly expressed in pancreatic cancer tissues, and it is related to the clinical characteristics and prognosis of patients. It is expected to be a new molecular marker to predict the prognosis of pancreatic cancer.