OBJECTIVE: Exercise, as a common non-drug intervention, is one of several lifestyle choices known to reduce the risk of cancer. Mitochondrial division has been reported to play a key role in the occurrence and transformation of hepatocellular carcinoma (HCC). This study investigated whether exercise could regulate the occurrence and development of HCC through mitosis. METHODS: Bioinformatics technology was used to analyze the expression level of dynamin-related protein 1 (DRP1), a key protein of mitochondrial division. The effects of DRP1 and DRP1 inhibitor (mdivi-1) on the proliferation and migration of liver cancer cells BEL-7402 were observed using cell counting kit-8, plate colony formation, transwell cell migration, and scratch experiments. Enzyme-linked immunosorbent assay, Western blot and real-time polymerase chain reaction were used to detect the expression of DRP1 and its downstream phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway. A treadmill exercise intervention was tested in a nude mouse human liver cancer subcutaneous tumor model expressing different levels of DRP1. The size and weight of subcutaneous tumors in mice were detected before and after exercise. RESULTS: The expression of DRP1 in liver cancer tissues was significantly upregulated compared with normal liver tissues (P < 0.001). The proliferation rate and the migration of BEL-7402 cells in the DRP1 over-expression group were higher than that in the control group. The mdivi-1 group showed an inhibitory effect on the proliferation and migration of BEL-7402 cells at 50 μmol/L. Aerobic exercise was able to inhibit the expression of DRP1 and decrease the size and weight of subcutaneous tumors. Moreover, the expression of phosphorylated PI3K (p-PI3K) and phosphorylated AKT (p-AKT) decreased in the exercise group. However, exercise could not change p-PI3K and p-AKT levels after knocking down DRP1 or using mdivi-1 on subcutaneous tumor. CONCLUSION Aerobic exercise can suppress the development of tumors partially by regulating DRP1 through PI3K/AKT pathway.
Animals ; Apoptosis ; Carcinoma, Hepatocellular/therapy* ; Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Dynamins ; Liver Neoplasms/therapy* ; Mice ; Phosphatidylinositol 3-Kinase/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Signal Transduction

OBJECTIVE: To explore the clinical features and disease-causing variants of a pediatric patient with fatal encephalopathy caused by mitochondrial peroxidase division deficiency, to identify the possible genetic causes of the disease and provide a basis for clinical diagnosis. METHODS: A child with fatal encephalopathy caused by mitochondrial peroxidase division deficiency in West China Second Hospital of Sichuan University was selected. The clinical manifestations, laboratory findings and disease-causing variant were analyzed. RESULTS: The main clinical symptoms of the patient were fever, headache and vomiting, followed by drug refractory epilepsy and progressive disturbance of consciousness. MRI showed deepening of sulcus, dilatation of bilateral ventricles, and multiple patch-like abnormal signals in paraventricular white matter, semioval center and subcortical white matter of bilateral frontal lobe. Gene detection showed a heterozygous missense variant c.1207C>T(p.Arg403Cys) in DNM1L, according to the American College of Medical Genetics and Genomics classification standards and guidelines for genetic variants, this variant was predicted to be pathogenic(PS1+PS2+PM2+PP3). After treated with gamma globulin, glucocorticoid, "mitochondrial cocktail therapy" and anti-epilepsy drugs, the condition of the patient was getting better, seizure attacks reduced and consciousness level improved. CONCLUSION The c.1207C>T variant in DNM1L gene may be the disease-causing variant for the patient, and the result of genetic testing provides a basis for the clinical diagnosis in this case.
Child ; Drug Resistant Epilepsy ; Dynamins ; Genomics ; Humans ; Mitochondria ; Mutation ; Peroxidase ; Seizures

The aim of this study was to investigate the effect of edaravone (Eda) on the balance of mitochondrial fusion and fission in Parkinson's disease (PD) cell model. A cell model of PD was established by treating PC12 cells with 500 μmol/L 1-methyl-4-phenylpyridinium (MPP). Thiazole blue colorimetry (MTT) was used to detect the effect of different concentrations of Eda on the survival rate of PC12 cells exposed to MPP. The mitochondrial morphology was determined by laser confocal microscope. Western blot was used to measure the protein expression levels of mitochondrial fusion- and fission-related proteins, including OPA1, MFN2, DRP1 and Fis1. The results showed that pretreatment with different concentrations of Eda antagonized MPP-induced PC12 cell damage in a dose-dependent manner. The PC12 cells treated with MPP showed mitochondrial fragmentation, up-regulated DRP1 and Fis1 protein expression levels, and down-regulated MFN2 and OPA1 protein expression levels. Eda could reverse the above changes in the MPP-treated PC12 cells, but did not affect Fis1 protein expression. These results suggest that Eda has a protective effect on the mitochondrial fusion disruption induced by MPP in PC12 cells. The mechanism may be related to the up-regulation of OPA1/MFN2 and down-regulation of DRP1.
1-Methyl-4-phenylpyridinium ; Animals ; Dynamins ; Edaravone ; pharmacology ; GTP Phosphohydrolases ; Mitochondria ; drug effects ; Mitochondrial Dynamics ; Mitochondrial Proteins ; PC12 Cells ; Parkinson Disease ; Rats ; Up-Regulation

Viperin is an IFN-stimulated gene (ISG)-encoded protein that was identified in human primary macrophages treated with IFN-γ and in human primary fibroblasts infected with cytomegalovirus (CMV). This protein plays multiple roles in various cell types. It inhibits viral replication, mediates signaling pathways, and regulates cellular metabolism. Recent studies have shown that viperin inhibits IFN expression in macrophages, while it enhances TLR7 and TLR9-mediated IFN production in plasmacytoid dendritic cells, suggesting that viperin can play different roles in activation of the same pathway in different cell types. Viperin also controls induction of ISGs in macrophages. However, the effect of viperin on induction of ISGs in cell types other than macrophages is unknown. Here, we show that viperin differentially induces ISGs in 2 distinct cell types, macrophages and fibroblasts isolated from wild type and viperin knockout mice. Unlike in bone marrow-derived macrophages (BMDMs), viperin downregulates the expression levels of ISGs such as bone marrow stromal cell antigen-2, Isg15, Isg54, myxovirus resistance dynamin like GTPase 2, and guanylate binding protein 2 in murine embryonic fibroblasts (MEFs) treated with type I or II IFN. However, viperin upregulates expression of these ISGs in both BMDMs and MEFs stimulated with polyinosinic-polycytidylic acid or CpG DNA and infected with murine CMV. The efficiency of viral entry is inversely proportional to the expression levels of ISGs in both cell types. The data indicate that viperin differentially regulates induction of ISGs in a cell type-dependent manner, which might provide different innate immune responses in distinct cell types against infections.
Animals ; Carrier Proteins ; Cytomegalovirus ; Dendritic Cells ; DNA ; Dynamins ; Fibroblasts ; GTP Phosphohydrolases ; Humans ; Immunity, Innate ; Interferons ; Macrophages ; Mesenchymal Stromal Cells ; Metabolism ; Mice ; Mice, Knockout ; Orthomyxoviridae ; Poly I-C

BACKGROUNDIt is well documented that sevoflurane postconditioning (SP) has a significant myocardial protection effect. However, the mechanisms underlying SP are still unclear. In the present study, we investigated the hypothesis that the Pim-1 kinase played a key role in SP-induced cardioprotection by regulating dynamics-related protein 1 (Drp1).

METHODSA Langendorff model was used in this study. Seventy-two rats were randomly assigned into six groups as follows: CON group, ischemia reperfusion (I/R) group, SP group , SP+proto-oncogene serine/threonine-protein kinase 1 (Pim-1) inhibitor II group, SP+dimethylsufoxide group, and Pim-1 inhibitor II group (n = 12, each). Hemodynamic parameters and infarct size were measured to reflect the extent of myocardial I/R injury. The expressions of Pim-1, B-cell leukemia/lymphoma 2 (Bcl-2) and cytochrome C (Cyt C) in cytoplasm and mitochondria, the Drp1 in mitochondria, and the total Drp1 and p-Drp1ser637 were measured by Western blotting. In addition, transmission electron microscope was used to observe mitochondrial morphology. The experiment began in October 2014 and continued until July 2016.

RESULTSSP improved myocardial I/R injury-induced hemodynamic parametric changes, cardiac function, and preserved mitochondrial phenotype and decreased myocardial infarct size (24.49 ± 1.72% in Sev group compared with 41.98 ± 4.37% in I/R group; P< 0.05). However, Pim-1 inhibitor II significantly (P < 0.05) abolished the protective effect of SP. Western blotting analysis demonstrated that, compared with I/R group, the expression of Pim-1 and Bcl-2 in cytoplasm and mitochondria as well as the total p-Drp1ser637 in Sev group (P < 0.05) were upregulated. Meanwhile, SP inhibited Drp1 compartmentalization to the mitochondria followed by a reduction in the release of Cyt C. Pretreatment with Pim-1 inhibitor II significantly (P < 0.05) abolished SP-induced Pim-1/p-Drp1ser637 signaling activation.

CONCLUSIONSThese findings suggested that SP could attenuate myocardial ischemia-reperfusion injury by increasing the expression of the Pim-1 kinase. Upregulation of Pim-1 might phosphorylate Drp1 and prevent extensive mitochondrial fission through Drp1 cytosolic sequestration.

Animals ; Dynamins ; metabolism ; Hemodynamics ; drug effects ; Ischemic Postconditioning ; methods ; Male ; Methyl Ethers ; therapeutic use ; Mitochondria ; drug effects ; metabolism ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Proto-Oncogene Proteins c-pim-1 ; antagonists & inhibitors ; metabolism ; Quinazolinones ; pharmacology ; Rats ; Rats, Sprague-Dawley

Centronuclear myopathy (CNM) is a rare congenital myopathy that is pathologically characterized by the centrally locatednuclei in most of the muscle fibers. On clinical examination, dynamin 2 (DNM2)-related CNM typically shows distaldominant muscle atrophy, ptosis, ophthalmoplegia, and contracture. The reported cases of CNM in Caucasian studies showa high prevalence rate of early-onset ptosis and ophthalmoplegia and correlated with the severity of the disease. However,Asian reports show a low prevalence and late-onset ocular symptoms in DNM2-related CNM patients. p.R465W is one ofthe most commonly found mutations in Western countries, and all the cases showed ocular symptoms. The proband and hisdaughter had no ocular symptoms despite harboring the same p.R465W mutation. This family makes us speculate that ocularsymptoms in DNM2-related CNM are influenced by ethnic background. In addition, this is the first familial case of DNM2-related CNM in Korea.
Contracture ; Dynamin II ; Dynamins* ; Humans ; Korea ; Muscular Atrophy ; Muscular Diseases ; Myopathies, Structural, Congenital* ; Ophthalmoplegia ; Prevalence

To observe the protective effect and mechanism of Sailuotong capsule in focal cerebral ischemia/reperfusion. The 90 min middle cerebral artery occlusion (MCAO) reperfusion model was established. The expressions of dynamin-related protein 1 ( Drp1) and optic atrophy 1 (Opa1) were tested by Western blot. The transmission electron microscope was used to observe the changes in the mitochondrial ultra-structure. The pathological morphological changes were observed through the HE staining. The immunohistochemical method was used to test Drp1 and Opa1 expressions. Sailuotong capsule (33, 16.5 mg x kg(-1), ig) can inhibit the abnormal mitochondrial fission and fusion in the cortical area on the ischemia side and the mitochondrial fission gene expression and promote the mitochondrial fusion gene Opa1 expression, so as to alleviate the energy metabolism disorder caused by ischemia/reperfusion. Sailuotong capsule can inhibit the abnormal mitochondrial dynamics in peri-ischemic regions and maintain the normal morphology of mitochondria, which may be the mechanism of Sailuotong capsule in promoting the self-recovery function in the ischemic brain region.
Animals ; Brain ; drug effects ; metabolism ; Brain Ischemia ; drug therapy ; genetics ; metabolism ; surgery ; Drugs, Chinese Herbal ; administration & dosage ; Dynamins ; genetics ; metabolism ; GTP Phosphohydrolases ; genetics ; metabolism ; Humans ; Male ; Mitochondria ; drug effects ; metabolism ; Rats

OBJECTIVETo detect the levels of miR-499 and relative proteins in hearts of mice after exercise training, and investigate the mechanism of exercise-regulative apoptosis.

METHODSMale C57BL/6 mice were randomly divided into 3 groups( n = 14): sedentary (SE), exercise training 1 (ET1) and exercise training 2 (ET2) group. SE did not do any exercise. ET1 performed swimming training for 8 weeks. ET2 performed the same work as ET1 until the 5th week. Then, mice trained twice a day until the end of training. TUNEL assay was applied to test myocardial apoptosis, RT-PCR and Western blot were used to detect miR-499 and proteins levels respectively.

RESULTSCompared with SE, stress in ET1 failed to affect apoptotic index (AI) and miR-499-CaN-Drp-1 pathway (P > 0.05). In contrast, exercise load in ET2 increased miR-499 level, decreased Drp-1 level and AI with statistical significance respectively (P < 0.05), but neither CaN expression nor CaN activity was changed significantly (P > 0.05).

CONCLUSIONSwimming training can inhibit myocardial apoptosis, and the decrease in Drp-l may be responsible for the reduced myocardial apoptosis. CaN, the upstream protein, does not participate in exercise-regulative apoptosis.

Animals ; Apoptosis ; Dynamins ; metabolism ; Heart ; Male ; Mice ; Mice, Inbred C57BL ; MicroRNAs ; metabolism ; Mitochondria, Heart ; physiology ; Myocardium ; pathology ; Physical Conditioning, Animal ; Swimming

Mitochondrial functions are essential for the survival and function of neurons. Recently, it has been demonstrated that mitochondrial functions are highly associated with mitochondrial morphology, which is dynamically changed by the balance between fusion and fission. Mitochondrial morphology is primarily controlled by the activation of dynamin-related proteins including dynamin-related protein 1 (Drp1), which promotes mitochondrial fission. Drp1 activity is regulated by several post-translational modifications, thereby modifying mitochondrial morphology. Here, we found that phosphorylation of Drp1 at serine 616 (S616) is mediated by cyclin-dependent kinase 5 (CDK5) in post-mitotic rat neurons. Perturbation of CDK5 activity modified the level of Drp1S616 phosphorylation and mitochondrial morphology in neurons. In addition, phosphorylated Drp1S616 preferentially localized as a cytosolic monomer compared with total Drp1. Furthermore, roscovitine, a chemical inhibitor of CDKs, increased oligomerization and mitochondrial translocation of Drp1, suggesting that CDK5-dependent phosphorylation of Drp1 serves to reduce Drp1's fission-promoting activity. Taken together, we propose that CDK5 has a significant role in the regulation of mitochondrial morphology via inhibitory phosphorylation of Drp1S616 in post-mitotic neurons.
Animals ; Cells, Cultured ; Cyclin-Dependent Kinase 5/*metabolism ; Dynamins/analysis/*metabolism ; HeLa Cells ; Humans ; Mitochondria/metabolism ; Mitosis ; Neurons/*cytology/*metabolism ; Phosphorylation ; Rats

As the basic physiological function of synapses, vesicle cycling involves in many aspects of process. Among them, vesicle recycling is the basis of synaptic vesicle cycling. Studies show that clathrin mediated endocytosis is a major pathway of vesicle recycling, in which Dynamin plays an important role. Dynamin is a GTPases with molecular weight of 100 kD, which acts as "scissors" in the endocytosis, separating the clathrin coated pits from membrane. It has been found that Dynamin is associated with epilepsy, Alzheimer's disease, centronuclear myopathy, and several other neurological diseases. In this paper, we discussed the structure, function and regulation of Dynamin, and reviewed recent advance in the studies on Dynamin related diseases.
Clathrin ; physiology ; Coated Pits, Cell-Membrane ; physiology ; Dynamins ; physiology ; Endocytosis ; Humans ; Synapses ; physiology ; Synaptic Transmission ; Synaptic Vesicles ; physiology