1.Buyang Huanwu Decoction reduces mitochondrial autophagy in rheumatoid arthritis synovial fibroblasts in hypoxic culture by inhibiting the BNIP3-PI3K/Akt pathway.
Junping ZHAN ; Shuo HUANG ; Qingliang MENG ; Wei FAN ; Huimin GU ; Jiakang CUI ; Huilian WANG
Journal of Southern Medical University 2025;45(1):35-42
OBJECTIVES:
To investigate the role of the BNIP3-PI3K/Akt signaling pathway in mediating the inhibitory effect of Buyang Huanwu Decoction (BYHWT) on mitochondrial autophagy in human synovial fibroblasts from rheumatoid arthritis patients (FLS-RA) cultured under a hypoxic condition.
METHODS:
Forty normal Wistar rats were randomized into two groups (n=20) for daily gavage of BYHWT or distilled water for 7 days to prepare BYHWT-medicated or control sera. FLS-RA were cultured in routine condition or exposed to hypoxia (10% O2) for 24 h wigh subsequent treatment with IL-1β, followed by treatment with diluted BYHWT-medicated serum (5%, 10% and 20%) or control serum. AnnexinV-APC/7-AAD double staining and T-AOC kit were used for detecting apoptosis and total antioxidant capacity of the cells, and the changes in ROS, ATP level, mitochondrial membrane potential and Ca2+ homeostasis were analyzed. The changes in mRNA and protein expressions of BNIP3, PI3K and AKT and mRNA expressions of LC3, Beclin-1 and P62 were detected using RT-qPCR and Western blotting.
RESULTS:
Treatment with BYHWT-medicated serum dose-dependently lowered apoptosis rate of IL-1β-induced FLS-RA with hypoxic exposure. The treatment significantly decreased T-AOC concentration, increased ROS production, autophagosome formation and ATPase levels, and lowered mitochondrial membrane potential and Ca2+ level in the cells. In IL-1β-induced FLS-RA with hypoxic exposure, treatment with BYHWT-medicated serum significantly increased BNIP3 protein expression, decreased the protein expressions of PI3K and AKT, increased the mRNA expressions of BNIP3 and P62, and lowered the mRNA expressions of PI3K, AKT, LC3 and Beclin-1 without significantly affecting Beclin-1 protein expression. The cells treated with 5% and 10% BYHWT-medicated serum showed no significant changes in LC3 expression.
CONCLUSIONS
BYHWT inhibits mitochondrial autophagy in IL-1β-induced FLS-RA with hypoxic exposure possibly by inhibiting BNIP3-mediated PI3K/AKT signaling pathway.
Drugs, Chinese Herbal/pharmacology*
;
Arthritis, Rheumatoid/pathology*
;
Animals
;
Signal Transduction/drug effects*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Autophagy/drug effects*
;
Humans
;
Fibroblasts/cytology*
;
Rats, Wistar
;
Membrane Proteins/metabolism*
;
Rats
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Mitochondria/metabolism*
;
Cells, Cultured
;
Proto-Oncogene Proteins/metabolism*
;
Apoptosis/drug effects*
;
Cell Hypoxia
;
Synovial Membrane/cytology*
;
Male
;
Mitochondrial Proteins
2.Hypertension exacerbates postoperative learning and memory impairment in rats possibly due to UCP2 downregulation-mediated mitochondrial dysfunction.
Luyu LIU ; Maowei GONG ; Guosong LIAO ; Weixing ZHAO ; Qiang FU
Journal of Southern Medical University 2025;45(4):725-735
OBJECTIVES:
To explore the correlation of hypertension with postoperative cognitive dysfunction and its possible mechanism.
METHODS:
Twelve-week-old spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats were both randomized into control group and surgical group (n=8). In the latter group, the rats received carotid artery exposure surgery under sevoflurane anesthesia to establish models of postoperative learning and memory impairment. Postoperative cognitive function changes of the rats were evaluated using behavioral tests. The hippocampus of the rats were collected for determining ATP level and mitochondrial membrane potential (MMP) and for detecting expressions of UCP2 and astrocyte markers (GFAP and NOX4) using Western blotting and immunofluorescence staining. Serum levels of ROS, IL-6, IL-1β and TNF‑α were detected using ELISA. Nissl staining was used to examine hippocampal neuronal loss in the CA1 region.
RESULTS:
The SHRs exhibited exacerbated learning and memory deficits following the surgery as shown by significantly reduced performance in novel object recognition tests and context-related and tone-related fear conditioning experiments. Compared with WKY rats, the SHRs had significantly decreased mitochondrial UCP2 expression and MMP in the hippocampus, increased hippocampal ATP level, and markedly increased serum levels of ROS and inflammatory factors, showing also increased activation of hippocampal astrocytes and microglia and reduced number of neurons positive for Nissl staining.
CONCLUSIONS
Hypertension can exacerbate major postoperative learning and memory impairment in rats possibly as a result of UCP2-mediated mitochondrial dysfunction and oxidative stress damage, which further leads to astrocyte overactivation and neuronal damage.
Animals
;
Rats, Inbred SHR
;
Rats
;
Uncoupling Protein 2
;
Rats, Inbred WKY
;
Hypertension/physiopathology*
;
Hippocampus/metabolism*
;
Mitochondria/metabolism*
;
Down-Regulation
;
Male
;
Memory Disorders/etiology*
;
Mitochondrial Proteins/metabolism*
3.Qianggu Kangshu Formula attenuates osteoclast differentiation in rheumatoid arthritis by inhibiting the HIF-1α/BNIP3 autophagy signaling pathway.
Weiyi LI ; Lu JIANG ; Zongxing ZHANG ; Dan CHEN ; Zhuoma BAO ; Li HUANG ; Lin YUAN
Journal of Southern Medical University 2025;45(7):1389-1396
OBJECTIVES:
To investigate the effect of Qianggu Kangshu Formula (QGKSF) for alleviating osteoclast differentiation in rheumatoid arthritis and the underlying mechanism.
METHODS:
RAW264.7 cells cultured under hypoxic conditions were treated with RANKL to induce osteoclast differentiation and incubated with normal rat serum or sera from rats medicated with methotrexate (MTX) or QGKSF at low and high doses. Cell viability, TRAP-positive multinucleated cells and F-actin ring formation in the treated cells were assessed with CCK-8 assay, TRAP staining and Phalloidin staining, respectively. Autophagy and autophagosomes in the cells were observed with MDC staining and transmission electron microscopy. ELISA was used to measure IL-6 and TNF-α levels in the culture supernatant, and the expressions of HIF-1α, BNIP3, Bcl-2, Beclin1, LC3-I, LC3-II, P62 and TRAP mRNAs and proteins were analyzed using RT-qPCR and Western blotting.
RESULTS:
In hypoxia- and RANKL-induced RAW264.7 cells treated with normal rat serum, significant increments of TRAP-positive cells and F-actin ring formation were observed with an enhanced autophagic fluorescence intensity and increased autophagosomes. Treatment of the induced cells with rat sera medicated with MTX and low- and high-dose QGKSF obviously reduced the TRAP-positive cells, F-actin rings and autophagosomes as well as the autophagic fluorescence intensity. RANKL treatment significantly increased IL-6 and TNF-α levels in RAW264.7 cells, which were obviously decreased by treatment with MTX- and QGKSF-medicated sera. RANKL also significantly increased the mRNA and protein expression levels of HIF-1α, BNIP3, Bcl-2, Beclin1, LC3 and TRAP and lowered P62 expressions, and these changes were effectively reversed by treatment with MTX- and QGKSF-medicated sera.
CONCLUSIONS
QGKSF attenuates RANKL-induced osteoclast differentiation in hypoxic RAW264.7 cells by inhibiting the HIF-1α/BNIP3 autophagy signaling pathway, suggesting its potential for treatment of bone destruction in rheumatoid arthritis.
Animals
;
Drugs, Chinese Herbal/pharmacology*
;
Osteoclasts/drug effects*
;
Autophagy/drug effects*
;
Mice
;
Signal Transduction/drug effects*
;
Rats
;
Cell Differentiation/drug effects*
;
Arthritis, Rheumatoid/pathology*
;
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
;
RAW 264.7 Cells
;
Membrane Proteins/metabolism*
;
Mitochondrial Proteins
4.Inhibition of ferroptosis alleviates acute kidney injury caused by diquat in zebrafish.
Zejin OU ; Ying LI ; Shi CHEN ; Ziyi WANG ; Meiyi HE ; Zhicheng CHEN ; Shihao TANG ; Xiaojing MENG ; Zhi WANG
Journal of Southern Medical University 2025;45(8):1743-1750
OBJECTIVES:
To investigate the role of ferroptosis in diquat-induced acute kidney injury (AKI) and its molecular mechanisms.
METHODS:
Transgenic zebrafish models with Tg (Eco.Tshb:EGFP) labeling of the renal tubules and Tg (lyz:dsRed2) labeling of the neutrophils were both divided into control group, gentamicin (positive control) group, diquat poisoning group, ferroptosis inhibitor group. The indicators of kidney injury, inflammatory response, and ferroptosis were examined in the zebrafish, and the changes in expressions of voltage-dependent anion-selective channel protein 1 (VDAC1) and mitochondrial ferritin (FTMT) were detected using Western blotting.
RESULTS:
AKI induced by diquat exhibited a significant dose-effect relationship, and the severity of injury was proportional to the exposure concentration. Diquat also caused marked oxidative stress and inflammatory responses in the zebrafish models. Rhodamine metabolism assay and HE staining revealed significantly declined glomerular filtration function of the zebrafish as diquat exposure concentration increased. Immunofluorescence staining highlighted significant changes in the expressions of ferroptosis markers GPX4 and FTH1 in zebrafish renal tissues following diquat exposure. In diquat-exposed zebrafish, treatment with ferrostatin-1, a ferroptosis inhibitor, obviously upregulated GPX4 and downregulated FTH1 expressions and improved the metabolic rate of glucan labeled with rhodamine B. Diquat exposure significantly upregulated the expression of VDAC1 and FTMT in zebrafish, and the application of ferrostatin-1 and VBIT-12 (a VDAC1 inhibitor) both caused pronounced downregulation of FTMT expression.
CONCLUSIONS
Ferroptosis is a critical mechanism underlying diquat-induced AKI, in which VDAC1 and FTMT play important regulatory roles, suggesting their potential as therapeutic target for AKI caused by diquat.
Animals
;
Zebrafish
;
Ferroptosis/drug effects*
;
Acute Kidney Injury/chemically induced*
;
Diquat/toxicity*
;
Animals, Genetically Modified
;
Voltage-Dependent Anion Channel 1/metabolism*
;
Ferritins/metabolism*
;
Oxidative Stress
5.Study on the effects of telomerase reverse transcriptase in alleviating doxorubicin induced cardiotoxicity.
Qingqing GU ; Qianwe CHEN ; Yu WANG ; Dabei CAI ; Tingting XIAO ; Qingjie WANG ; Ling SUN
Chinese Critical Care Medicine 2025;37(6):583-589
OBJECTIVE:
To investigate the role of telomerase reverse transcriptase (TERT) in alleviating doxorubicin (DOX)-induced cardiotoxicity.
METHODS:
(1) Cell experiments: rat H9c2 cardiomyocytes were divided into control group (CON group), null adenovirus transfection group (NC group), TERT overexpression adenovirus transfection group (TERT group), DOX group (treated with 1 μmol/L DOX for 12 hours), DOX+NC group, and DOX+TERT group (null adenovirus or TERT overexpression adenovirus were transfected for 24 hours and then treated with 1 μmol/L DOX for 12 hours). The mRNA expression of TERT in cardiomyocytes was detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The level of mitochondrial membrane potential was detected by immunofluorescence. The expression levels of intracellular Bax, Bcl-2, microtubule-associated protein 1 light chain 3 (LC3) and p62 were detected by Western blotting. (2) Animal experiments: male C57BL/6 mice were randomly divided into a sham operation group (Sham group), DOX group (acute cardiotoxicity model was constructed by intraperitoneal injection of DOX 15 mg/kg), DOX+NC group and DOX+TERT group (modeled after transfection with airborne adenovirus or TERT overexpression adenovirus for 7 days). After 7 days of modeling, the area of myocardial fibrosis was detected by Sirius scarlet staining, and cardiac function was detected by echocardiography.
RESULTS:
(1) Cellular experiments: the mRNA expression level of TERT was significantly higher in the TERT group compared with the CON and NC groups. Compared with the CON group, the TERT mRNA expression level of cardiomyocytes in the DOX group and the DOX+NC group were significantly lower, the level of mitochondrial membrane potential was significantly lower, the protein expressions of Bax and LC3 were significantly increased, and the protein expressions of Bcl-2 and p62 were significantly decreased. No significant differences were found between the DOX group and DOX+NC group. Compared with the DOX group and DOX+NC group, the TERT mRNA expression level was increased in the DOX+TERT group (relative expression: 1.02±0.10 vs. 0.61±0.05, 0.54±0.03, both P < 0.05), the level of mitochondrial membrane potential was significantly increased (1.14±0.05 vs. 0.96±0.01, 0.96±0.01, both P < 0.05), the protein expressions of Bax and LC3 were significantly decreased, and the protein expressions of Bcl-2 and p62 were significantly increased (Bax/β-actin: 0.88±0.01 vs. 1.31±0.02, 1.26±0.01; LC3-II/I: 2.16±0.05 vs. 2.64±0.06, 2.58±0.02; Bcl-2/β-actin: 0.65±0.01 vs. 0.40±0.01, 0.41±0.01; p62/β-actin: 0.45±0.01 vs. 0.23±0.02, 0.29±0.01; all P < 0.05). (2) Animal experiments: compared with the Sham group, the percentage of myocardial fibrosis area was significantly increased and left ventricular ejection fraction (LVEF) and fractional shortening (FS) were significantly decreased in the DOX group and DOX+NC group. Compared with the DOX group and DOX+NC group, the percentage of myocardial fibrotic area was significantly decreased in the DOX+TERT group (%: 2.33±0.06 vs. 3.76±0.07, 3.87±0.06, both P < 0.05), and the LVEF and FS were significantly increased [LVEF (%): 67.00±1.14 vs. 54.60±1.57, 53.40±2.18; FS (%): 38.60±0.51 vs. 30.60±1.10, 30.00±0.71; all P < 0.05].
CONCLUSION
Up-regulation of TERT expression can inhibit DOX-induced cardiomyocyte autophagy and apoptosis, attenuate DOX-induced myocardial fibrosis in mice, improve cardiac function, and thus alleviate DOX-induced cardiotoxicity.
Animals
;
Doxorubicin/toxicity*
;
Telomerase/metabolism*
;
Myocytes, Cardiac/metabolism*
;
Rats
;
Male
;
Cardiotoxicity
;
Mice, Inbred C57BL
;
Mice
;
Membrane Potential, Mitochondrial
;
Adenoviridae
;
bcl-2-Associated X Protein/metabolism*
;
Proto-Oncogene Proteins c-bcl-2/metabolism*
;
Transfection
;
Apoptosis
6.Research Progress in the Function and Regulation of Sirtuin 3 in Sepsis-Related Diseases.
Jun-Jie LI ; Hong MEI ; Xin-Xin LIU ; Kun YU ; Bang-Hai FENG ; Bao FU ; Song QIN
Acta Academiae Medicinae Sinicae 2025;47(4):601-610
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection,with a high mortality rate.Sirtuin 3,a deacetylase within mitochondria,plays an important regulatory role in cellular metabolism,oxidative stress,and inflammatory responses.In recent years,significant progress has been made in the study of the function and regulatory role of sirtuin 3 in sepsis-related diseases.Research has shown that sirtuin 3 can alleviate organ damage caused by sepsis by regulating mitochondrial function,reducing oxidative stress,and inhibiting inflammatory responses.The specific mechanisms include the regulation of mitochondrial bioenergetics,activation of antioxidant enzyme systems,and inhibition of inflammatory mediator expression.In addition,sirtuin 3 plays a protective role in the pathological process of sepsis by interacting with multiple signaling pathways.This article summarizes the functions and regulatory mechanisms of sirtuin 3 in various sepsis-related diseases,aiming to provide new targets and strategies for the prevention and treatment of sepsis in the future.
Sepsis/metabolism*
;
Sirtuin 3/physiology*
;
Humans
;
Animals
;
Oxidative Stress
;
Mitochondria/metabolism*
;
Signal Transduction
7.Impact of tyrosine phosphorylation site mutation in FUNDC1 protein on mitophagy in H9c2 cardiomyocytes.
Zhaoyang ZHANG ; Yanli YU ; Jieyun WU ; Wei TIAN ; Jingman XU
Chinese Journal of Cellular and Molecular Immunology 2025;41(7):629-636
Objective To investigate the effect of FUNDC1 tyrosine phosphorylation site mutations on mitophagy in H9c2 myocardial cells by constructing tyrosine site mutant plasmids (Y11 and Y18) of the FUN14 domain-containing protein 1 (FUNDC1). Methods The mutant plasmids constructed by whole-gene synthesis were transfected into rat myocardial H9c2 cells and divided into five groups: empty plasmid group, FUNDC1 overexpression group, Y11 mutant group, Y18 mutant group, and Y11 combined with Y18 mutant group. The viability of H9c2 cells was assessed using the CCK-8 assay. Additionally, tetramethylrhodamine ethyl ester (TMRE) staining was utilized to detect mitochondrial membrane potential. The protein expression levels of FUNDC1, translocase of the outer mitochondrial membrane 20 (TOM20), and cytochrome c oxidase IV (COX IV) were detected by Western blot analysis. Confocal microscopy was used to evaluate transfection efficiency as well as the co-localization of mitochondria and lysosomes. Results The FUNDC1 overexpression, Y11, Y18, and Y11 combined with Y18 mutant plasmids were successfully constructed. After plasmid transfection, widespread GFP fluorescence expression was observed under confocal microscopy. Compared with the empty plasmid group, FUNDC1 protein expression levels were significantly increased in the FUNDC1 overexpression group, Y11 mutation group, Y18 mutation group, and Y11 combined with Y18 mutation group, while cell viability and mitochondrial membrane potential showed no significant changes. Compared to the empty plasmid group, cells transfected with Y18 and Y11 combined with Y18 mutant plasmids showed increased TOM20 and COX IV expression levels and decreased mitochondrial-lysosomal co-localization. Conclusion Transfection with FUNDC1 Y18 or Y11 combined with Y18 mutant plasmids inhibited mitophagy in H9c2 myocardial cells.
Animals
;
Rats
;
Mitophagy/genetics*
;
Myocytes, Cardiac/cytology*
;
Mitochondrial Proteins/metabolism*
;
Mutation
;
Phosphorylation
;
Tyrosine/genetics*
;
Cell Line
;
Membrane Proteins/metabolism*
;
Membrane Potential, Mitochondrial
8.Combined oxidative phosphorylation deficiency type 7 caused by C12orf65 gene mutations: a case report and literature review.
Xiao-Yi CHEN ; Yong-Jie ZHU ; Jie DENG ; Yan-Li MA ; Jun-Fang SUO ; Yuan WANG ; Yuan-Ning MA
Chinese Journal of Contemporary Pediatrics 2025;27(2):205-211
OBJECTIVES:
To investigate the clinical features and gene mutation characteristics of combined oxidative phosphorylation deficiency type 7 (COXPD7) caused by mutations in the C12orf65 gene, and to enhance the awareness of this disease.
METHODS:
A child diagnosed with COXPD7 in the Department of Neurology, Children's Hospital Affiliated to Zhengzhou University in 2021 was included, along with 10 patients reported in the literature. All subjects were analyzed for their genotypes and clinical phenotypes.
RESULTS:
A total of 11 patients with COXPD7 were included, comprising 1 reported in this study and 10 from the literature. Among the 11 patients, 9 had homozygous mutations in the C12orf65 gene, while 2 had compound heterozygous mutations, which were identified as frameshift or nonsense mutations. The age of onset ranged from 1 day to 2 years, and clinical manifestations included optic nerve atrophy and delays in intellectual and motor development. Eight patients exhibited external ophthalmoplegia, and five patients displayed spastic paralysis. Cranial magnetic resonance imaging revealed optic nerve atrophy in all 11 patients, abnormal brainstem signals in 10 patients, and a lactate peak on brainstem magnetic resonance spectroscopy scans in 3 patients.
CONCLUSIONS
COXPD7 associated with the C12orf65 gene results from homozygous or compound heterozygous mutations, with primary clinical manifestations of optic nerve atrophy and delays in intellectual and motor development. Some patients may also present with spastic paralysis or external ophthalmoplegia. Cranial imaging reveals symmetrical abnormal signals in bilateral basal ganglia and brainstem, and a lactate peak is observed on brainstem magnetic resonance spectroscopy scans.
Child, Preschool
;
Female
;
Humans
;
Infant
;
Male
;
Mitochondrial Diseases/genetics*
;
Mitochondrial Proteins/genetics*
;
Mutation
;
Oxidative Phosphorylation
;
Infant, Newborn
9.Clinical characteristics and genetic analysis of two children with Multiple mitochondrial dysfunction syndrome due to variants of IBA57 gene.
Qiuping WU ; Shan CHEN ; Lijuan LIU ; Xiangshu WEN ; Jingjing LI
Chinese Journal of Medical Genetics 2025;42(1):69-73
OBJECTIVE:
To investigate the clinical features and genetic variants associated with Multiple mitochondrial dysfunction syndrome (MMDS) type 3 in two children.
METHODS:
Two children diagnosed with MMDS type 3 at Zhuhai Maternal and Child Health Care Hospital in January 2021 were selected for this study. A retrospective analysis of their clinical data was carried out. Whole exome sequencing was conducted on the two children and their parents, followed by Sanger sequencing for candidate variants and bioinformatic analysis. Both children received comprehensive rehabilitative therapy and were followed up for 3 years. This study was approved by the Ethics Committee of Zhuhai Maternal and Child Health Hospital (Ethics No. 202380).
RESULTS:
The two MMDS type 3 children were monozygotic twin girls, aged 9 months, presenting with developmental regression, pyramidal signs, and other clinical manifestations. Cranial MRI revealed widespread abnormal signals and vacuolar changes in the white matter. Whole exome sequencing revealed that both children had harbored compound heterozygous variants of the IBA57 gene, namely c.286T>C (p.Tyr96His) and c.307C>T (p.Gln103Ter). Sanger sequencing confirmed that these variants were inherited from their father and mother, respectively. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, both variants were classified as pathogenic (PM2_Supporting+PM3_Very Strong+PP3_Moderate; PVS1+PM2_Supporting+PM3). After treatment with vitamins, levocarnitine, ATP, coenzyme Q10, and other drugs, both children showed partial recovery of neurodevelopmental regression, with improvement in feeding and sleep. Over the 3-year follow-up, there was slow but progressive improvement in motor, language, and cognitive development.
CONCLUSION
The compound heterozygous variants c.286T>C (p.Tyr96His) and c.307C>T (p.Gln103Ter) of the IBA57 gene probably underlay the MMDS type 3 in the twin pair. Clinicians should be vigilant about the possibility of MMDS type 3 in children with neurodevelopmental regression and early cranial MRI findings indicating widespread white matter abnormalities with vacuolar changes, as these may be indicative of IBA57 gene variants.
Female
;
Humans
;
Infant
;
Calcium-Binding Proteins/genetics*
;
Exome Sequencing
;
Genetic Testing/methods*
;
Microfilament Proteins/genetics*
;
Mitochondrial Diseases/genetics*
;
Mutation
;
Retrospective Studies
;
Carrier Proteins
10.Genetic analysis of a Chinese pedigree affected with Charcot-Marie-Tooth type 2A2A due to a missense variant of MFN2 gene.
Yu HAN ; Jie LIANG ; Jiebin WU ; Jingfang ZHAI
Chinese Journal of Medical Genetics 2025;42(1):74-81
OBJECTIVE:
To explore the genotype-phenotype correlation in a Charcot-Marie-Tooth type 2A2A (CMT2A2A) pedigree and to provide genetic counseling for its subsequent pregnancies.
METHODS:
A Chinese pedigree presenting with "lower limb muscle atrophy and movement disorders" at the Prenatal Diagnosis Center of Xuzhou Central Hospital between January and August 2024 was selected as the study subject. Relevant clinical data were collected from the pedigree members. Peripheral blood samples from affected individuals, and amniotic fluid and/or chorionic villus samples were obtained for DNA extraction. Whole exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing. Pathogenicity assessment and bioinformatic analysis were conducted. This study was approved by the Medical Ethics Committee of Xuzhou Central Hospital (Ethics No. XZXY-LK-20240111-0019).
RESULTS:
All affected individuals in this pedigree were females, whom included the proband, her mother, and her first daughter. Earlier age of onset was associated with more severe lower limb atrophy. A heterozygous missense variant of the MFN2 gene, namely c.314C>T (p.Thr105Met), was identified in the proband, her mother, daughter, and the third fetus from a re-marriage. The same variant was absent in her elder brother, current husband, and her fourth fetus. Based on the guidelines from American College of Medical Genetics and Genomics (ACMG) and recommendations from Clinical Genome Resources (ClinGen), the variant was classified as pathogenic (PP1_Strong+PM1+PS3+PS4_Moderate+PP3_Moderate+PM2_Supporting). Analyses with PROVEAN and Mutation Taster had categorized the variant as "deleterious" and "disease-causing", respectively. Analysis with Uniprot and Jalview showed that the affected amino acid residue is conserved across multiple species. ChEBI software predicted that the variant may alter the polarity of the 105th amino acid residue.
CONCLUSION
The c.314C>T (p.Thr105Met) missense variant of the MFN2 gene probably underlie the CMT2A2A in this pedigree. Above finding has enabled prenatal diagnosis and genetic counseling for its subsequent pregnancies.
Adult
;
Female
;
Humans
;
Male
;
Charcot-Marie-Tooth Disease/genetics*
;
East Asian People/genetics*
;
Exome Sequencing
;
Genetic Testing/methods*
;
GTP Phosphohydrolases/genetics*
;
Mitochondrial Proteins/genetics*
;
Mutation, Missense
;
Pedigree

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