Purpose To investigate the relationship between mitochondrial DNA 11778 mutation and clinical characteristics of patients with Laber is hereditary optic neuropathy(LHON). Methods PCR RFLPs (MaeⅢ) and mutation specific primer PCR(MSP-PCR) were used simultaneously to detect mitochondrial DNA 11778 mutation. Results Among 10 subjects who habored 11778 mutation,one was a carrier and nine were patients with LHON.Of the nine patients,six were males and three were females.The age of onset ranged from 12 to 25 years old and the onset interval of the two eyed varied between 0 to 6 months. The visual acuity was CF/10cm-0.1 except one who lost her vision after delivery but recovered gradually.The results of visual field,VEP and color vision were abnormal but ERG and systemic status were all normal. Conclusion Molecular biological detection of the ten subjects showed that they all habored mtDNA 11778 mutation.The existence of carrier and visual recovery imlied that mtDNA mutation was a primary cause of LHON,but other factors such as endocrine disorder might influence the pathogenesis of LHON. (Chin J Ocul Fundus Dis,1998,14:156-158)
Objective To explore the effects of drugs on functions of mitochondria in retinal nerve cells, and to lay a foundation of the investigation of drug protection for retinal nerve cells. Methods Cultivation of the retinal nerve cells of 8 eyes of neonatal calves was performed. The changes of fluorescent density of the mitochondria of cultured cells labeled by dye rhodamine 123 (Rh123) before and after the activation of the medicines, including ferulic acid (FA), arginine, glycine,taurine, vitamine E and brain derived neurotrophic factor( BDNF) respectively, were detected by laser-scanning confocal microscopy. Results FA with the concentration of 500 μg/ml led the diphasic variation of the fluorescent intensity of mitochondria. After scanning for 60.772 seconds when treated with FA firstly, the fluorescent intensity decreased rapidly (from 45.425±4.153 to 22.135±5.293); while after 112.774 seconds when treated secondly, the in tensity increased obviously (from 19.655±4.383 to 28.247±4.764), and after 168.773 seconds when treated thirdly the intensity still increased. After scanning for 56.457 seconds when treated with vitamin E (12.5 mg/ml), the fluorescent in tensity increased obviously (from 88.255±5.039 to 111.273±4.529), which suggested that vitamin E with the concentration of 12.5 mg/ml strengthen the fluorescent intensity. After scanning for 58.147 and 134.148 seconds when treated with BDNF(50 ng/ml) respectively, the fluorescent intensity increased obviously (from 69.115±5.038 to 77.225±5.131) which suggested that BDNF with the concent ration of 50 ng/ml led the increase of the fluorescent intensity. Glycine (2.5 mg/ml) and arginine(30 mg/ml) didn’t affect the fluorescent intensity of mitochondria, and taurine (6.25 mg/ml) caused the appreciable decrease of the fluorescent intensity . Conclusion FA, BDNF and vitamin E may promote the metabolism of retinal nerve cells via the path of mitochondria, while amino acids may adjust the activation of retinal nerve cells through other ways. (Chin J Ocul Fundus Dis，2004，20：229-232)
The main function of mitochondrial fusion protein 1 （Mfn1） and mitochondrial fusion protein 2 （Mfn2） was originally thought to be just regulating the fusion of mitochondrial outer membrane. But in recent years，many studies on these two proteins show that they are involved in many important cellular physiological processes including proliferation，apoptosis，necrosis and regulation of respiratory function and oxidative metabolism. There are many aspects of the influenceof Mfn1 and Mfn2 on cardiomyocyte，which have not been thoroughly studied yet，sometimes with even contradictoryconclusions. But these two proteins definitely have significant impact on the growth，development and physiological functionof cardiomyocyte. To investigate the function and mechanism of Mfn1 and Mfn2 in various physiological processes of cardiomyocyte is of great significance for in vitro studies of physiological functions of cardiomyocyte and technological development of myocardial tissue engineering and transplantation in vivo. This article mainly focuses on recent research progress of the influence of Mfn1 and Mfn2 on various physiological functions of cardiomyocyte.
Objective To analyze the glucolipotoxicity effects of glucose combined with free fatty acid (FFA) on ketone production and ultrastructure of skeletal muscle, by exogenous elevating circulating glucose and FFA concentration. Methods Fifty Wistar rats were divided into high-fat-feed induced obesity group (OB group, n=40) and ordinary feed as normal control group (NC group, n=10). Circulating glucose and FFA levels were increased by infusion in high-fat-fed obese rats. The levels of serum lipid, plasma FFA and beta-hydroxybutyric acid were detected by the horizontal colorimetry, and the microstructure of skeletal muscle was observed by transmission electron microscopy, especially the changes of the mitochondrial structure. Euglycemic-hyperinsulinemic clamp with tracer infusion was performed to assess peripheral insulin sensitivity. Results The average weight and body fat ratio in the OB group was higher than that in the NC group (P<0.05). Insulin clamp test to assess peripheral insulin sensitivity showed that the steady-state glucose Infusion rate in the OB group during clamp test was significantly lower than that in the NC group [OB: (19.26±1.84) mg/(kg·min)vs. NC: (28.82±1.69) mg/(kg·min), P<0.05]. The mitochondrial denaturation of skeletal muscle in the OB group of rats was observed, and the swelling and crest permutation, the accumulation of lipid droplets and cavitation were formed, and hypertrophy of mitochondria were also seen after intralipid and glucose infusion, which was obvious in the combined infusion group. Conclusions By exogenous elevating circulating glucose and FFA concentration, the products of ketone body increases. The mitochondrial damage of skeletal muscle suggests that mitochondrial may be the potential target of glucoxicity and lipotocicity.
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.
Alzheimer’s disease (AD) is the most common degenerative disease of the nervous system. Studies have found that the 40 Hz pulsed magnetic field has the effect of improving cognitive ability in AD, but the mechanism of action is not clear. In this study, APP/PS1 double transgenic AD model mice were used as the research object, the water maze was used to group dementia, and 40 Hz/10 mT pulsed magnetic field stimulation was applied to AD model mice with different degrees of dementia. The behavioral indicators, mitochondrial samples of hippocampal CA1 region and electrocardiogram signals were collected from each group, and the effects of 40 Hz pulsed magnetic field on mouse behavior, mitochondrial kinetic indexes and heart rate variability (HRV) parameters were analyzed. The results showed that compared with the AD group, the loss of mitochondrial crest structure was alleviated and the mitochondrial dynamics related indexes were significantly improved in the AD + stimulated group (P < 0.001), sympathetic nerve excitation and parasympathetic nerve inhibition were improved, and the spatial cognitive memory ability of mice was significantly improved (P < 0.05). The preliminary results of this study show that 40 Hz pulsed magnetic field stimulation can improve the mitochondrial structure and mitochondrial kinetic homeostasis imbalance of AD mice, and significantly improve the autonomic neuromodulation ability and spatial cognition ability of AD mice, which lays a foundation for further exploring the mechanism of ultra-low frequency magnetic field in delaying the course of AD disease and realizing personalized neurofeedback therapy for AD.
To investigate the mechanisms of hepatic injury after biliary obstruction. After a rat model of complete biliary obstruction(CBO) was induced, hepatocyte mitochondria was isolated and the calcium content of mitochondria, the contents of liver malondialdyhyde (MDA) and superoxide dismutase (SOD), the levels of serum T-Bil, ALT, ALP and GGT were measured in each group. Results: After CBO, mitochondrial calcium content, liver MDA and serum T-Bil, ALT, ALP, GGT became increased progressively, compared with control group (Ｐ＜0.05); the liver SOD was decreased markedly (Ｐ＜0.05). Mitochondrial calcium content was highly positively correlated with liver MDA content, serum ALT and ALP, r values were 0.967, 0.924 and 0.919 respectively (Ｐ＜0.01). The liver MDA content was highly positively correlated with serum ALT and ALP, r values were 0.949 and 0.843 respectively (Ｐ＜0.01). Conclusions: Mitochondrial calcium overload and liver lipid peroxidation may be the important mechanisms of hepatic injury induced by biliary obstruction.
Objective\ To study the mechanism of myocardial protection of exogenous creatine phosphate (CP) against ischemia reperfused injury in modified isolated perfused working rat heart model.\ Methods\ Seventy two rats were divided into five groups.The rat hearts of five groups undergone Langendorff perfused were arrested and made totally ischemic for 40 minutes at 37℃ and reperfused for 20 minutes. St.Thomas cardioplegic solution wasn’t used in group A;It was used immediately after ischemia in group B and grou...
Objective To explore the feasibility of identifying clonal origin of hepatocellular carcinoma (HCC) by analyzing the mitochondrial DNA D-Loop region variations. Methods Forty-two patients with a total of 112 HCC nodules consequentially hospitalized for radical resection of HCC in the department of hepatobiliary surgery of the First Affiliated Hospital of Guangxi Medical University from April 2004 to August 2007 were included for study group (multinodular HCCs). Control group included 20 cases of HCC (40 samples) hospitalized in the same period that consisted of two sub-groups: control groupⅠconsisted of 16 cases of single nodular HCC that each had two pieces of inconsecutive tumor tissues and control groupⅡconsisted of 4 cases of HCC with portal vein tumor embolus whose tumor tissues and portal vein tumor embolus were collected simultaneously. Normal control included 5 patients who were donors for liver transplantation or underwent liver trauma without any liver disease. Polymerase chain reaction (PCR) and direct sequencing were applied to study the mtDNA D-Loop region. The sequences of multinodular lesions were compared among different groups. Results For all the 42 cases of the study group, basic group variations appeared in 131 sites (131/1 122, 11.7%, the number 1 122 was the length of mtDNA D-Loop) with point mutation in 15 sites, insert in 9 sites, and deletion in 16 sites. And of all the variations in the study group, 98 were polymorphism. In study group, 20 cases were categorized as multicentric occurrence (MO) based on their variant mtDNA D-Loop sequences in each nodule from the same patient. And 22 cases were characterized as intrahepatic metastasis (IM) based on the identical mtDNA D-Loop sequences found in each nodule from the same patient. In all 20 cases in the control group, the inconsecutive tumor tissues or the portal vein tumor embolus and original tumors shared identical mtDNA D-Loop sequences. For the normal control group, basic group variations appeared in 14 sites, and they were all polymorphism including a new polymorphism (NT 479 Agt;G). Conclusions There is a high rate of changes in mtDNA D-Loop region. And our study speculates a novel discrimination of MO and IM origins among multinodular HCCs using PCR and direct sequencing of the mtDNA D-Loop sequences.
Objective To investigate the potential mechanism of cellular senescence-related mitochondrial autophagy genes in diabetic retinopathy (DR). MethodsThe DR gene datasets GSE53257 and GSE60436 from the GEO database and screened the differentially expressed genes (DEG) were downloaded. Cellular senescence-related genes and mitochondrial autophagy-related genes from the GeneCards database, and the intersection of the two to obtain the DR-related differentially expressed genes (CSRMRDEG) were collected. The obtained CSRMRDEG was subjected to Gene Ontology (GO) functional enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis, protein-protein interaction network (PPI) analysis, and hub gene identification using Maximal Clique Centrality (MCC), Degree, Maximum Neighborhood Component (MNC)、Edge Percolated Component (EPC) and Closeness algorithms. Gene Set Enrichment Analysis (GSEA) was conducted to obtain the enriched pathways of DEG, and ssGSEA immune infiltration analysis was performed to screen the correlation between immune cells and DR. The diagnostic efficacy of hub genes for DR was evaluated by drawing the receiver operating characteristic (ROC) curve and calculating the area under the curve (AUC). Meanwhile, the Wilcoxon rank sum test was used to compare the differences in the infiltration level of immune cells between the DR Group and the control group. Results23 DR-related CSRMRDEG were obtained. GO analysis showed that they were mainly enriched in the pathways of dicarboxylic acid, biosynthetic process of folate-containing compounds, tetrahydrofolate conversion, mitochondrial matrix, mitochondrial endomembrane, structural components of ribosomes, and glutamate transmembrane transporter protein activity. The results of KEGG pathway enrichment analysis showed that CSRMRDEG was highly enriched in pathways such as the folate carbon pool, biosynthesis of cofactors, and pyruvate metabolism. The PPI analysis results show that there are 16 related CSRMRDEG. Five algorithms (MCC, Degree, MNC, EPC, Closeness) obtained the nine Hub genes. The results of ROC curve analysis showed that the AUC of the expression levels of 9 hub genes for diagnosing DR ranged from 0.7-0.9. The ssGSEA results showed that there were statistically significant differences in Wilcoxon of central memory CD4+ T cells, macrophages, natural killer cells, and helper T cell 1 between the DR group and the control group (Z=−2.85, −2.23, −2.10, −2.52; P＜0.05). ConclusionMitochondrial autophagy genes related to cellular senescence are potential diagnostic targets for DR.