1.Clinical and genetic analysis of essential hypertension with mitochondrial tRNAMet 4435A>G and YARS2 mutation
Meili GUO ; Yunfan HE ; Ade CHEN ; Zaishou ZHUANG ; Xiaoyong PAN ; Minxin GUAN
Journal of Zhejiang University. Medical sciences 2024;53(2):184-193
Objective:To investigate the role of m.4435A>G and YARS2 c.572G>T(p.G191V)mutations in the development of essential hypertension.Methods:A hypertensive patient with m.4435A>G and YARS2 p.G191V mutations was identified from previously collected mitochondrial genome and exon sequencing data.Clinical data were collected,and a molecular genetic study was conducted in the proband and his family members.Peripheral venous blood was collected,and immortalized lymphocyte lines constructed.The mitochondrial transfer RNA(tRNA),mitochondrial protein,adenosine triphosphate(ATP),mitochondrial membrane potential(MMP),and reactive oxygen species(ROS)in the constructed lymphocyte cell lines were measured.Results:Mitochondrial genome sequencing showed that all maternal members carried a highly conserved m.4435A>G mutation.The m.4435A>G mutation might affect the secondary structure and folding free energy of mitochondrial tRNA and change its stability,which may influence the anticodon ring structure.Compared with the control group,the cell lines carrying m.4435A>G and YARS2 p.G191V mutations had decreased mitochondrial tRNA homeostasis,mitochondrial protein expression,ATP production and MMP levels,as well as increased ROS levels(all P<0.05).Conclusion:The YARS2 p.G191V mutation aggravates the changes in mitochondrial translation and mitochondrial function caused by m.4435A>G through affecting the steady-state level of mitochondrial tRNA and further leads to cell dysfunction,indicating that YARS2 p.G191V and m.4435A>G mutations have a synergistic effect in this family and jointly participate in the occurrence and development of essential hypertension.
2.Mitochondrial tRNA(Thr)T15943C mutation may be a new position that affects the phenotypic expression of deafness associated 12s rRNA A1555G mutation.
Hongli XIAO ; Zheyun HE ; Yinglong GAO ; Yaling YANG ; Jing ZHENG ; Zhaoyang CAI ; Binjiao ZHENG ; Xiaowen TANG ; Minxin GUAN
Chinese Journal of Medical Genetics 2015;32(2):163-168
OBJECTIVETo identify secondary mutations associated with deafness in a Chinese family affected with deafness.
METHODSThe family has been subjected to clinical and molecular analyses, in addition with measurement of reactive oxygen species and doubling time after establishment of immortalized lymphocyte cell lines.
RESULTSThe results showed that the hearing loss level and audiometric configuration were discrepant among the family members with maternally transmitted hearing loss. The penetrance of hearing loss in this family was respectively 66.7% and 44.4% when aminoglycoside-induced hearing loss was included or excluded. Analysis of whole mitochondrial genome has found 33 variants as previously reported polymorphisms, except for a 12s rRNA A1555G mutation and a tRNA(Thr)T15943C mutation. Haplotype evolutionary tree has verified that this family belonged to East-Asian haplogroup F. 15943 position was located on the T-stem of the tRNA(Thr), which has destroyed the extremely conserved T-A base pair when T changed to C at this position. However, functional experiments indicated that the population doubling time in special galactose and glucose were longer, whilst the level of reactive oxygen species has increased. Compared with the control cell line groups and a family only carrying the 12s rRNA A1555G mutation, all of the three groups belonged to the same haplogroup.
CONCLUSIONMitochondrial tRNA(Thr)T15943C mutation may act as a potential modifying factor and interact with 12s rRNA A1555G mutation, and thereby enhance the penetrance and expression of deafness.
Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; China ; DNA, Mitochondrial ; genetics ; Deafness ; genetics ; Female ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Pedigree ; Phenotype ; Point Mutation ; RNA, Ribosomal ; genetics ; RNA, Transfer, Thr ; genetics ; Young Adult
3.Urinary continence-related structures and intraoperative protective techniques in radical prostatectomy
Minxin HE ; Geng TIAN ; Tie CHONG ; Delai FU
Journal of Modern Urology 2023;28(12):1086-1091
Radical prostatectomy (RP) is the standard treatment for patients with early-stage of prostate cancer,but often causes urinary incontinence and other complications, which harm patients’ quality of life. The protection and reconstruction of urinary continence-related structures during the operation are significant approaches to reduce the incidence of urinary incontinence and restore urinary continence. This article reviewed the surgical approaches of radical prostatectomy, anatomy of urinary continence-related structures (bladder neck, functional urethra, supporting structures, nerves and vessels) and the protective skills,hoping to provide reference for the treatment of early-stage prostate cancer.
4.Clinical and genetic analysis of essential hypertension with CYB gene m.15024G>A mutation.
Yunfan HE ; Wenxu LI ; Zhen LIU ; Juanjuan ZHANG ; Minxin GUAN
Journal of Zhejiang University. Medical sciences 2023;52(4):510-517
OBJECTIVES:
To explore the role of mitochondrial CYB 15024G>A mutation in the development of essential hypertension.
METHODS:
Mitochondrial genome sequences of hypertensive patients were obtained from previous studies. Clinical and genetic data of a hypertensive patient with mitochondrial CYB 15024G>A mutation and its pedigree were analyzed. Lymphocytes derived from patient and family members were transformed into immortalized lymphoblastoid cell lines, and the levels of adenosine triphosphate (ATP), mitochondrial membrane potential and intracellular reactive oxygen species (ROS) were detected.
RESULTS:
The penetrance of this essential hypertension family was 42.9%, and the age of onset was 46-68 years old. Mitochondrial genome sequencing results showed that all maternal members carried a highly conserved mitochondrial CYB 15024G>A mutation. This mutation could affect the free energy of mitochondrial CYB for secondary and tertiary structure and protein folding, thereby changing its structural stability and the structure of the electron transfer function area around the mutation site. Compared with the control, the cell line carrying the mitochondrial CYB 15024G>A mutation showed significantly decreased levels of mitochondrial CYB, ATP and mitochondrial membrane potential, and increased levels of ROS (P<0.01).
CONCLUSIONS
Mitochondrial CYB 15024G>A mutation may affect the structure of respiratory chain subunits and mitochondrial function, leading to cell dysfunction, which suggests that the mutation may play a synergistic role in essential hypertension.
Humans
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Middle Aged
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Aged
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Reactive Oxygen Species
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Essential Hypertension/genetics*
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Adenosine Triphosphate
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Cell Line
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Mutation