Osteoarthritis (OA) is a degenerative articular disorder manifested by cartilage destruction, subchondral sclerosis, osteophytes, and synovitis, resulting in chronic joint pain and physical disability in the elderly. The purpose of this study was to investigate mitochondrial DNA copy number (mtDNA_CN) and inflammatory cytokines in primary knee OA patients and healthy volunteers. A total of 204 knee OA patients and 169 age-matched healthy volunteers were recruited. Their relative blood leukocyte mtDNA_CN was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), and ten inflammatory cytokines in their plasma were detected by multiplex immunoassay. Blood leukocyte mtDNA_CN in the OA group was significantly lower than that in the control group. Leukocyte mtDNA_CN in the control group was negatively correlated with their age (r=-0.380, P<0.0001), whereas mtDNA_CN in the OA group was positively correlated with their age (r=0.198, P<0.001). Plasma interleukin-4 (IL-4) and IL-6 were significantly higher in the knee OA group than in the control group. The plasma IL-6 level was positively correlated with blood leukocyte mtDNA_CN in the OA group (r=0.547, P=0.0014). IL-5 showed as a major factor (coefficient 0.69) in the second dimension of principle components analysis (PCA)-transformed data and was significantly higher in the OA group (P<0.001) as well as negatively correlated with mtDNA_CN (r=-0.577, P<0.001). These findings suggest that elevation of plasma IL-4 and IL-6 and a relative reduction in mtDNA_CN might be effective biomarkers for knee OA. IL-5 is a plausible factor responsible for decreasing blood leukocyte mtDNA_CN in knee OA patients.
Age Factors ; Aged ; Aged, 80 and over ; Cytokines/blood* ; DNA, Mitochondrial/blood* ; Female ; Gene Dosage ; Humans ; Leukocytes/metabolism* ; Male ; Middle Aged ; Osteoarthritis, Knee/metabolism* ; Principal Component Analysis

OBJECTIVE: : To screen genes involved in mitochondrial DNA (mtDNA) damage repair in rats with septic acute kidney injury (SAKI). METHODS: : Forty male C57BL/6J mice were randomly divided into SAKI group (=28) and sham operation group (=12). The SAKI mouse model was established by cecal ligation and puncture. Blood and kidney samples were collected at 8, 24, and 48 h after surgery. Serum creatinine and urea nitrogen were measured by a dry biochemical analyzer. Serum inflammatory cytokines were detected by ELISA. Histopathological changes were observed with HE staining. The mtDNA damage repair related genes were screened by RNA sequencing and bioinformatics analysis; the mRNA and protein expression levels of related genes were detected by real-time quantitative RT-PCR and immunohistochemisry, respectively. RESULTS: : Symptoms of sepsis were observed in SAKI group, and 16 out of 28 mice were died in the SAKI group; serum TNF-α, IL-6, creatinine and urea nitrogen levels were higher than those in the sham group (<0.05 or <0.01). Histopathological examination in SAKI group showed that renal tubular epithelial cells were swollen, inflammatory cells infiltrated, and a large number of cell vacuoles were seen, suggesting successful modeling. Mitochondrial DNA damage repair related genes and were screened out. The expression of these genes was detected by real-time RT-PCR, and the results were consistent with RNA sequencing trends. Immunohistochemical staining showed that Gadd45α was mainly expressed in the nucleus of renal tubular epithelial cells, and the positive rate of Gadd45α in SAKI group was higher than that in the sham operation group (<0.05). CONCLUSIONS : and genes are involved in mtDNA damage repair in rats with SAKI, indicating that these genes may be used as new targets for prevention and treatment of SAKI.
Acute Kidney Injury ; physiopathology ; Animals ; Blood Urea Nitrogen ; Creatinine ; blood ; DNA Repair ; genetics ; DNA, Mitochondrial ; Male ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Rats ; Sepsis ; physiopathology

Background: Leigh syndrome (LS) is a rare disease caused by mitochondrial defects and has high phenotypic and genotypic heterogeneity. We analyzed the clinical symptoms, neuroimaging, muscular histopathology, and genotypes of 13 Chinese LS patients with mitochondrial DNA (mtDNA) mutations. Methods: Mutations in mtDNA were identified by targeted sequencing. The brain imaging features on magnetic resonance imaging (MRI) were analyzed. The levels of lactate in fasting blood and cerebrospinal fluid (CSF) were routinely tested. The levels of urinary organic acids, plasma amino acids, and acylcarnitines were examined with gas chromatography-mass spectrometry and tandem mass spectrometry. The histopathological traits of skeletal muscles were analyzed under microscope. Results: Among 13 patients, mutations of MT-NDs (n = 8) and MT-ATP6 (n = 4) genes were most common. Strabismus (8/13), muscle weakness (8/13), and ataxia (5/13) were also common, especially for the patients with late-onset age after 2 years old. However, respiratory distress was common in patients with early-onset age before 2 years old. The most frequently affected brain area in these patients was the brain stem (12/13), particularly the dorsal part of midbrain, followed by basal ganglia (6/13), thalamus (6/13), cerebellum (5/13), and supratentorial white matter (2/13). Besides, the elevated lactate levels in CSF (6/6) were more common than those in serum (7/13). However, the analysis of abnormal plasma amino acid and urinary organic acid showed limited results (0/3 and 1/4, respectively). Muscular histopathology showed mitochondrial myopathy in the three late-onset patients but not in the early-onset ones. Conclusions Noninvasive genetic screening is recommended for mtDNA mutations in MT-NDs and MT-ATP6 genes in patients with ophthalmoplegia, muscle weakness, ataxia, and respiratory disorder. Furthermore, the lactate detection in CSF and the brain MRI scanning are suggested as the diagnosis methods for LS patients with mtDNA mutations.
Child ; Child, Preschool ; Creatine Kinase ; blood ; Cytochrome-c Oxidase Deficiency ; DNA, Mitochondrial ; genetics ; Fasting ; blood ; cerebrospinal fluid ; Female ; Humans ; Infant ; Lactic Acid ; blood ; cerebrospinal fluid ; Leigh Disease ; diagnostic imaging ; genetics ; Magnetic Resonance Imaging ; Male ; Mutation ; genetics ; Neuroimaging ; methods

BACKGROUND: Previous studies suggest that habitual exercise can improve skeletal mitochondrial function; however, to date, the association between exercise and mitochondrial function in peripheral leukocytes has not been reported. The aim of this study was to evaluate the relationship between regular exercise and mitochondrial function by measuring leukocyte mitochondrial DNA (mtDNA) copy number in postmenopausal women. METHODS: This cross-sectional study included 144 relatively healthy, non-diabetic, non-smoking, postmenopausal women. Clinical parameters, including anthropometric measurements and cardio-metabolic parameters, were assessed. Regular exercise was defined as at least 150 minutes per week of moderate-intensity activity, or an equivalent combination of moderate and vigorous-intensity activity, over a duration of at least 6 months. Leukocyte mtDNA copy numbers were measured using real-time polymerase chain reaction assays, and these were normalized to the β-globin copy number to give the relative mtDNA copy number. RESULTS: The mtDNA copy number of peripheral leukocytes was significantly greater in the exercise group (1.33±0.02) than in the no exercise group (1.05±0.02, P<0.01). Stepwise multiple regression analysis showed that regular exercise was independently associated with mtDNA copy number (β=0.25, P<0.01) after adjusting for the variables age, body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, homeostasis model assessment of insulin resistance value, and levels of high-density lipoprotein cholesterol, triglycerides, and homocysteine. CONCLUSION: Regular exercise is associated with greater leukocyte mtDNA copy number in postmenopausal women.
Blood Pressure ; Body Mass Index ; Cholesterol ; Cross-Sectional Studies ; DNA, Mitochondrial* ; Female ; Homeostasis ; Homocysteine ; Humans ; Insulin Resistance ; Leukocytes* ; Lipoproteins ; Mitochondria ; Real-Time Polymerase Chain Reaction ; Triglycerides ; Waist-Hip Ratio

BACKGROUND: Previous studies suggest that habitual exercise can improve skeletal mitochondrial function; however, to date, the association between exercise and mitochondrial function in peripheral leukocytes has not been reported. The aim of this study was to evaluate the relationship between regular exercise and mitochondrial function by measuring leukocyte mitochondrial DNA (mtDNA) copy number in postmenopausal women. METHODS: This cross-sectional study included 144 relatively healthy, non-diabetic, non-smoking, postmenopausal women. Clinical parameters, including anthropometric measurements and cardio-metabolic parameters, were assessed. Regular exercise was defined as at least 150 minutes per week of moderate-intensity activity, or an equivalent combination of moderate and vigorous-intensity activity, over a duration of at least 6 months. Leukocyte mtDNA copy numbers were measured using real-time polymerase chain reaction assays, and these were normalized to the β-globin copy number to give the relative mtDNA copy number. RESULTS: The mtDNA copy number of peripheral leukocytes was significantly greater in the exercise group (1.33±0.02) than in the no exercise group (1.05±0.02, P<0.01). Stepwise multiple regression analysis showed that regular exercise was independently associated with mtDNA copy number (β=0.25, P<0.01) after adjusting for the variables age, body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, homeostasis model assessment of insulin resistance value, and levels of high-density lipoprotein cholesterol, triglycerides, and homocysteine. CONCLUSION: Regular exercise is associated with greater leukocyte mtDNA copy number in postmenopausal women.
Blood Pressure ; Body Mass Index ; Cholesterol ; Cross-Sectional Studies ; DNA, Mitochondrial* ; Female ; Homeostasis ; Homocysteine ; Humans ; Insulin Resistance ; Leukocytes* ; Lipoproteins ; Mitochondria ; Real-Time Polymerase Chain Reaction ; Triglycerides ; Waist-Hip Ratio

BACKGROUNDMitochondrial diseases are a group of energy metabolic disorders with multisystem involvements. Variable clinical features present a major challenge in pediatric diagnoses. We summarized the clinical spectrum of m.3243A>G mutation in Chinese pediatric patients, to define the common clinical manifestations and study the correlation between heteroplasmic degree of the mutation and clinical severity of the disease.

METHODSClinical data of one-hundred pediatric patients with symptomatic mitochondrial disease harboring m.3243A>G mutation from 2007 to 2013 were retrospectively reviewed. Detection of m.3243A>G mutation ratio was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Correlation between m.3243A>G mutation ratio and age was evaluated. The differences in clinical symptom frequency of patients with low, middle, and high levels of mutation ratio were analyzed by Chi-square test.

RESULTSSixty-six patients (66%) had suffered a delayed diagnosis for an average of 2 years. The most frequent symptoms were seizures (76%), short stature (73%), elevated plasma lactate (70%), abnormal magnetic resonance imaging/computed tomography (MRI/CT) changes (68%), vomiting (55%), decreased vision (52%), headache (50%), and muscle weakness (48%). The mutation ratio was correlated negatively with onset age (r = -0.470, P < 0.001). Myopathy was more frequent in patients with a high level of mutation ratio. However, patients with a low or middle level of m.3243A>G mutation ratio were more likely to suffer hearing loss, decreased vision, and gastrointestinal disturbance than patients with a high level of mutation ratio.

CONCLUSIONSOur study showed that half of Chinese pediatric patients with m.3243A>G mutation presented seizures, short stature, abnormal MRI/CT changes, elevated plasma lactate, vomiting, and headache. Pediatric patients with these recurrent symptoms should be considered for screening m.3243A>G mutation. Clinical manifestations and laboratory abnormalities should be carefully monitored in patients with this point mutation.

Adolescent ; Age of Onset ; Asian Continental Ancestry Group ; Chi-Square Distribution ; Child ; Child, Preschool ; DNA, Mitochondrial ; genetics ; Female ; Hearing Loss ; pathology ; physiopathology ; Humans ; Infant ; Lactic Acid ; blood ; Magnetic Resonance Imaging ; Male ; Mitochondrial Diseases ; blood ; genetics ; pathology ; physiopathology ; Mutation ; Point Mutation ; genetics ; Polymerase Chain Reaction ; Retrospective Studies ; Seizures ; pathology ; physiopathology

OBJECTIVETo investigate the relationship between the changes of the copy numbers of mtDNA in peripheral blood mono-nucle- ar cell(PBMC) and the disordered of antioxidant capacity of hepatocellular carcinoma (HCC) patients.

METHODSThe Ficoll Hypaque method was used to isolate the PBMC from blood specimens. The ND1 gene of the mitochondrial was amplified by real-time PCR; meantime β-actin was served as a quantitative standard marker; the difference of mtDNA copy number in PBMC was compared between HCC and healthy control group. The level of reactive oxygen species (ROS) in PBMC was determined by flow cytometry. The change of total antioxidant capacity (T- AOC) of plasma was detected by the biochemistry examination.

RESULTSThe copy numbers of ND1 gene in PBMC of HCC was 73% that of the healthy control group,which suggested a decrease of the copy numbers of mtDNA in HCC. The levels of ROS of PBMC in HCC was (417. 82 ± 110.62) and (301.82 ± 75.54) in control group, which showed that the levels of ROS of PBMC in HCC were significant higher than that in control group (P < 0.01).Plasma T-AOC in HCC was (1.30 ± 0.85), and (3.20 ± 1.62) in control. The T-AOC of plasma of HCC was significantly lower than in control group (P < 0.01).

CONCLUSIONThere was a certain relationship between the decrease of the copy numbers of mtDNA and the disordered antioxidant capacity in hepatocellular carcinoma, which may be associated with the development of hepatocellular carcinoma.

Actins ; Antioxidants ; metabolism ; Carcinoma, Hepatocellular ; blood ; genetics ; Case-Control Studies ; DNA Copy Number Variations ; DNA, Mitochondrial ; genetics ; Humans ; Leukocytes, Mononuclear ; metabolism ; Liver Neoplasms ; blood ; genetics ; Reactive Oxygen Species ; metabolism

BACKGROUND: A newborn screening (NBS) program has been utilized to detect asymptomatic newborns with inherited metabolic diseases (IMDs). There have been some bottlenecks such as false-positives and imprecision in the current NBS tests. To overcome these issues, we developed a multigene panel for IMD testing and investigated the utility of our integrated screening model in a routine NBS environment. We also evaluated the genetic epidemiologic characteristics of IMDs in a Korean population. METHODS: In total, 269 dried blood spots with positive results from current NBS tests were collected from 120,700 consecutive newborns. We screened 97 genes related to NBS in Korea and detected IMDs, using an integrated screening model based on biochemical tests and next-generation sequencing (NGS) called NewbornSeq. Haplotype analysis was conducted to detect founder effects. RESULTS: The overall positive rate of IMDs was 20%. We identified 10 additional newborns with preventable IMDs that would not have been detected prior to the implementation of our NGS-based platform NewbornSeq. The incidence of IMDs was approximately 1 in 2,235 births. Haplotype analysis demonstrated founder effects in p.Y138X in DUOXA2, p.R885Q in DUOX2, p.Y439C in PCCB, p.R285Pfs*2 in SLC25A13, and p.R224Q in GALT. CONCLUSIONS: Through a population-based study in the NBS environment, we highlight the screening and epidemiological implications of NGS. The integrated screening model will effectively contribute to public health by enabling faster and more accurate IMD detection through NBS. This study suggested founder mutations as an explanation for recurrent IMD-causing mutations in the Korean population.
Computational Biology ; DNA/chemistry/isolation & purification/metabolism ; Dried Blood Spot Testing ; Galactokinase ; Genomics ; Haplotypes ; High-Throughput Nucleotide Sequencing ; Humans ; Incidence ; Infant, Newborn ; Membrane Proteins/genetics ; Metabolic Diseases/*diagnosis/epidemiology/genetics ; Metabolism, Inborn Errors/diagnosis/epidemiology/genetics ; Mitochondrial Membrane Transport Proteins/genetics ; Neonatal Screening ; Polymorphism, Genetic ; Republic of Korea/epidemiology ; Sequence Analysis, DNA

OBJECTIVETo explore the role of mitochondrial DNA 5178 C/A (Mt5178) polymorphism of NADH-dehydrogenase subunit 2 (ND2) gene in type-2 diabetes mellitus (T2DM) among ethnic Han Chinese through a case-control study.

METHODSThe Mt5178C/A polymorphism was determined by sequencing 1103 T2DM patients and 791 healthy controls. Logistic regression analysis was conducted to estimate odds ratios (OR) and 95% confidence intervals (CI). To confirm the results, a meta-analysis was conducted based on published literature on the association of Mt5178 variant with T2DM.

RESULTSNo significant association was found between the Mt5178C/A variant and T2DM either by our study or the meta-analysis which included eight published studies. Nevertheless, it was found that the T2DM patients with 5178C genotype were at a higher risk for nephropathy complication (OR=1.49, 95%CI: 1.005-2.197, P<0.05) and at significantly lower risk for hypertension complication (OR=0.744, 95%CI: 0.556-0.996, P<0.05) compared with those carrying a 5178A genotype.

CONCLUSIONNo association was found between the Mt5178C/A polymorphism of mitochondrial ND2 gene with the increased risk of T2DM. However, the polymorphism may affect the development of nephropathy and hypertension complications among T2DM patients.

Adult ; Aged ; Blood Glucose ; metabolism ; Cholesterol ; blood ; Cholesterol, HDL ; blood ; DNA, Mitochondrial ; chemistry ; genetics ; Diabetes Complications ; blood ; genetics ; Diabetes Mellitus, Type 2 ; blood ; complications ; genetics ; Diabetic Nephropathies ; blood ; genetics ; Fasting ; blood ; Female ; Humans ; Hypertension ; blood ; complications ; genetics ; Male ; Meta-Analysis as Topic ; Middle Aged ; Odds Ratio ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA ; Triglycerides ; blood

OBJECTIVES: Infants with slight/mild or late-onset hearing impairment might be missed in universal newborn hearing screening (UNHS). We identified the mutation hot spot of common deaf gene in the newborns in Jinan area population by screening the mutation spot with neonate cord blood, in order to make clear whether the neonate cord blood for screening is feasible. METHODS: Six hundred and forty-six newborns were subjected to both UNHS and genetic screening for deafness by using neonate cord blood. The newborn genetic screening targeted four deafness-associated genes, which were commonly found in the Chinese population including gap junction beta-2 protein (GJB2), gap junction beta-3 protein (GJB3), solute carrier family 26 member 4 (SLC26A4), and mtDNA 12S rRNA. The most common 20 spot mutations in 4 deaf genes were detected by MassARRAY iPLEX platform and mitochondrial 12S rRNA A1555G and C1494T mutations were sequenced using Sanger sequencing. RESULTS: Among the 646 newborns, 635 cases passed the UNHS and the other 11 cases (1.7%) did not. Of the 11 failures, two cases were found to carry homozygous GJB2 p.R143W pathogenic mutation, one case was found to have heterozygous GJB2 235delC mutation, and another one case carried heterozygous GJB3 p.R180X pathogenic mutation. Six hundred and thirty-five babies passed the newborn hearing screening, in which 25 babies were identified to carry pathogenic mutations, including 12 heterozygotes (1.9%) for GJB2 235delC, eight heterozygotes (1.3%) for SLC26A4 IVS7-2A>G, one heterozygote (0.2%) for p.R409H, two homozygotes (0.3%) for m.1494C>T, and two homozygotes (0.3%) for m.1555A>G. CONCLUSION: Newborn genetic screening through the umbilical cord blood for common deafness-associated mutations may identify carriers sensitive to aminoglycoside antibiotic, and can effectively prevent or delay hearing loss occurs.
Asian Continental Ancestry Group ; China* ; Deafness* ; DNA, Mitochondrial ; Fetal Blood ; Gap Junctions ; Genetic Testing ; Hearing ; Hearing Loss ; Heterozygote ; High-Throughput Nucleotide Sequencing ; Homozygote ; Humans ; Infant ; Infant, Newborn* ; Mass Screening*