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)
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.
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.
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.
Optic atrophy,hereditary／diagnosis; Polymerase chain reaction; DNA,mitochondrial; Point mutation; Sequence analysis
ObjectiveTo observe the clinical features of patients over 30 years old with Leber hereditary optic neuropathy (LHON). MethodsNine male LHON patients (18 eyes) were enrolled in this study. The patients aged from 34 to 56 years old, with an average age of (45.22±6.91) years. The course of the disease ranged from 7 days to 21 months, with a mean course of 5 months. Visual acuity, slit lamp microscope, chromoptometry, direct ophthalmoscope and fundus photography were measured for all patients, visual field examined for 6 patients (11 eyes). Mitochondrial DNA mutation was analyzed. The visual acuity was followed-up for 12 months. ResultsSeven of the 9 patients (77.78%) had family history. Five patients (55.56%) had both eyes involved simultaneously, and 4 patients (44.44%) had the eyes involved at different time. Three patients (33.33%) had sudden visual loss, and 6 patients (66.67%) had gradual visual loss. The visual acuity was light perception in 1 eye (5.55%), finger counting in 3 eyes (16.67%), 0.01-0.1 in 7 eyes (38.89%), 0.12-0.3 in 3 eyes (16.67%), equal or greater than 0.4 in 4 eyes (22.22%). Sixteen eyes (88.88%) had normal light reflex, 1 eye (5.55%) had no light reflex, and 1 eye (5.55%) had relative afferent papillary defect. Eight eyes (44.44%) had normal optic disk, 3 eyes (16.67%) had blurred optic disc border and disc telangiectasia, 7 eyes (38.89%) had pale disc and clear boundary. Among 11 eyes underwent visual field examination, 9 eyes (81.82%) had central or paracentral scotoma and 2 eyes (18.18%) had visual field narrowing. Among 9 patients, there were 7 patients (77.78%) with G11778A mutation, 1 patient (11.11%) with G11696A mutation, and 1 patient (11.11%) with T14484C mutation. In the last follow-up, the visual acuity was light perception in 1 eye (5.55%), finger counting in 4 eyes (22.22%), 0.01-0.1 in 6 eyes (33.33%), 0.12-0.3 in 3 eyes (16.67%), equal or greater than 0.4 in 4 eyes (22.22%).The visual acuity was improved in 9 eyes (50.00%), stable in 7 eyes(38.89%), and decreased in 2 eyes (11.11%). ConclusionLHON patients (older than 30 years) are more common in men, mostly with normal light reflex, central or paracentral scotoma and G11778A mutation.
Objective To investigate the major types and clinical manifestations of mitochondrial DNA (mtDNA)mutations in Chinese patients with Leber′s hereditary optic neuropathy(LHON). Methods A total of 119 patients with bilateral optic neuropathy from 117 pedigrees, including 37 with determinate diagnosis of LHON(group A) and 82 with suspected LHON(group B),were tested for mtDNA mutations by using single-strand conformational polymorphism, mutation-specific primer polymerase chain reaction and sequencing. Pertinent clinical data and history of the patients with the 11778 mutation were collected. Results Nucleotide positions(np)11778 mutation and np 14484 mutation was found in 33 (89.2%) and 3 (8.1%) patients respectively in group A, while np 11778 mutation was obtained in 26（31.7%）in group B. No 3460 mutation was found in group A or B. The clinical manifestations of 59 patients with np 11778 mutation were as follows: acute or chronic visual loss，no ophthalmalgia, the age of onset of 10-25, and either a central or paracentral scotoma in perimetry. The visual recovery rate was 8.6%～11.6%. Conclusion Chinese patients with LHON have a very high incidence of np 11778 mutation and the clinical manifestations of the patients with np 11778 mutation are similar to those of Caucasian patients. (Chin J Ocul Fundus Dis，2004，20：78-80)
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.
Objective To observe the oxidative damage of mtDNA, apoptosis and expression of adhesion molecules in retinal capillary cells of diabetic rat with different disease courses. Methods One hundred Sprague-Dawley rats were randomly divided into the control group and the experimental group. The rats of experimental group were induced with streptozotocin (STZ) injection creating a diabetic model. Then they were divided into DR1m, DR2m DR3m group according to disease courses. The rats of control group were divided into NR1m, NR2m, NR3m group. Rat retinal capillaries were prepared, and then the contents of undamaged mtDNA were examined by Southern blot combined with Fpg. The expression of cyclooxygenase (COX)-1 encoded by mtDNA and transcription factors A (mtTFA) mRNA were detected by real-time quantitative polymerase chain reaction (RT-PCR). Apoptosis and expression of intercellular adhesion molecule-1 (ICAM-1) were detected by terminal dUT nick endlabeling (TUNEL) immuno-fluorescence and immunohistochemistry respectively. Results The contents of undamaged mtDNA in rats of DR1m, DR2m, DR3m were less than those of NR1m、NR2m、NR3m. The contents of undamaged mtDNA in diabetic rats decreased with the increase of disease courses. In addition, the mRNA levels of COX-1 and mtTFA were downregulated in diabetic rats. The positive cells of TUNEL and ICAM-1TUNEL and ICAM-1 in diabetic rats increased with the increase of disease courses. Conclusion With the increase of disease courses, mtDNA damage and apoptotic cells are increased, while the expression of mRNA encoded by mtDNA and ICAM-1 decreased in retinal capillary cells in diabetic rats.
ObjectiveTo summarize the role of chondrocyte mitochondrial homeostasis imbalance in the pathogenesis of osteoarthritis (OA) and analyze its application prospects. Methods The recent literature at home and abroad was reviewed to summarize the mechanism of mitochondrial homeostasis imbalance, the relationship between mitochondrial homeostasis imbalance and the pathogenesis of OA, and the application prospect in the treatment of OA. Results Recent studies have shown that mitochondrial homeostasis imbalance, which is caused by abnormal mitochondrial biogenesis, the imbalance of mitochondrial redox, the imbalance of mitochondrial dynamics, and damaged mitochondrial autophagy of chondrocytes, plays an important role in the pathogenesis of OA. Abnormal mitochondrial biogenesis can accelerate the catabolic reaction of OA chondrocytes and aggravate cartilage damage. The imbalance of mitochondrial redox can lead to the accumulation of reactive oxygen species (ROS), inhibit the synthesis of extracellular matrix, induce ferroptosis and eventually leads to cartilage degradation. The imbalance of mitochondrial dynamics can lead to mitochondrial DNA mutation, decreased adenosine triphosphate production, ROS accumulation, and accelerated apoptosis of chondrocytes. When mitochondrial autophagy is damaged, dysfunctional mitochondria cannot be cleared in time, leading to ROS accumulation, which leads to chondrocyte apoptosis. It has been found that substances such as puerarin, safflower yellow, and astaxanthin can inhibit the development of OA by regulating mitochondrial homeostasis, which proves the potential to be used in the treatment of OA. Conclusion The mitochondrial homeostasis imbalance in chondrocytes is one of the most important pathogeneses of OA, and further exploration of the mechanisms of mitochondrial homeostasis imbalance is of great significance for the prevention and treatment of OA.