1.Genetic polymorphisms of brain-derived neurotrophic factor and sporadic Parkinson disease
Dan HU ; Zhihou LIANG ; Xiang REN ; Mugen LIU ; Tao WANG ; Shenggang SUN
Chinese Journal of Tissue Engineering Research 2005;9(17):196-197
BACKGROUND: Brain-derived neurotrophic factor(BDNF) is a potent dopaminergic neurotrophin. The major pathological change in Parkinson disease(PD) is the degeneration and death of dopaminergic neurons in the substantia nigra pars compacta. There is a possibility that the onset of PD is associated with BDNF genetic polymorphisms.OBJECTIVE: To investigate the relationship between BDNF genetic polymorphisms and sporadic Parkinson disease(SPD) in Chinese population with the expectation of offering some genetic data for the primary rehabilitation and prevention of the disease.DESIGN: Explorative study based on DNA samples of SPD patients as study group and DNA samples of healthy population as control group.SETTING: Neurological Department of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, and Human Genome Center of Huazhong University of Science and Technology.PARTICIPANTS: Subjects included DNA samples of 85 SPD patients(study group, Han population, living in Huazhong area for a long term) offered by Department of Neurology of Wuhan Union Hospital and DNA samples of health persons(control group, Han population, living in Huazhong area for a long term) offered by Human Genome Center of Huazhong University of Science and Technology.METHODS: The genotype of healthy controls and SPD patients was analyzed with the polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP).MAIN OUTCOME MEASURES: Genotypes and alleles of the two polymorphisms: G196A and C270T of the two groups.RESULTS: G/A genotype was dominant in both SPD patients and control group with frequencies of 50.6% and 52.0% respectively. The C/C genotype occurred with the frequency of 100% in both groups. There were no significant differences in genotype and allele frequencies of G196A and C270T between SPD and control group( P > 0. 05).CONCLUSION: No association existed between BDNF genetic polymorphisms and the onset of SPD in Chinese Han population of Huazhong area.
2.Screening of ET-1 receptor antagonists and the pharmacological evaluation
Xin LI ; Zehui GONG ; Mugen CHI ; Fengzhen LI ; Junjun DONG ; Keliang LIU ; Jianquan ZHENG
Chinese Pharmacological Bulletin 2003;0(11):-
Aim Series of compounds,which were considered to be the antagonists of ET-1 receptor,were synthesized by Beijing Institute of Pharmacology and Toxicology.The biological activity of these compounds was screened and some active compounds were selected for further pharmacological characterization on pulmonary hypertension.Methods Radioligand binding assay was performed to study the binding affinity of compounds for ETA and ETB receptors.The biological activity of compounds was evaluated in isolated rat aortic ring and in systemic arterial pressure(SAP)of anesthetized rat experiments.In addition,hypotensive effect of compounds was investigated on monocrotaline induced pulmonary hypertension in rats.Results Compounds bind to ETA receptor had over 10 000 fold higher affinity than to ETB receptor.Contraction induced by ET-1 in isolated rat aortic ring was inhibited by compounds,and 1 ?mol?L-1 ETP-508 shifted the cumulative concentration-contraction response curve to ET-1 to right with no change in the maximal response.In vivo,the increase in SAP induced by ET-1 〔3.7 ?g?(0.5 ml)-1?kg-1〕 was inhibited by 2 mg?kg-1 compounds by intravenous infusion.Furthermore,BQ-485 and ETP-508 by intravenous infusion(0.4 mg?h-1)significantly inhibited 80 mg?kg-1(sc)monocrotaline induced pulmonary hypertension in rats.Conclusions These results indicate that ETP-508 and BQ-485 are highly selective ETA receptor antagonists and significantly inhibite monocrotaline induced pulmonary hypertension in rats.
4.Two novel mutations of the retinitis pigmentosa GTPase regulator gene in two Chinese families with X-linked retinitis pigmentosa.
Li LIU ; Haoming CHEN ; Mugen LIU ; Lei JIN ; Yong WEI ; Xuejun WU ; Youe LIU ; Renyuan XHU ; Jianhua CHAI
Chinese Medical Journal 2002;115(6):833-836
OBJECTIVETo detect mutations of the retinitis pigmentosa GTPase regulator (RPGR) gene in two Chinese X-linked retinitis pigmentosa families.
METHODSFragments of exons 1-19 of the RPGR gene were amplified with intronic primers, using genomic DNA as template. The polymerase chain reaction (PCR) products were analysed by single-strand conformation polymorphism (SSCP) and direct sequencing. Mutations were identified by comparing DNA sequences of the patients with those of the normal controls.
RESULTSTwo novel mutations, c1536delC and E332X, were identified in exons 12 and 9 of the RPGR gene in both families. Each mutation was the first mutation found in their respective exons. Both mutations were predicted to cause premature termination, which resulted in truncated proteins without normal functions of the RPGR products.
CONCLUSIONSBoth mutations are the genetic basis of the pathogenesis in the respective families. Our data might be helpful in analysing the function of the RPGR protein.
Carrier Proteins ; genetics ; Eye Proteins ; Female ; Genetic Linkage ; Humans ; Male ; Mutation ; Polymerase Chain Reaction ; Polymorphism, Single-Stranded Conformational ; Retinitis Pigmentosa ; genetics ; Sequence Analysis, DNA ; X Chromosome
5.Identification of a new lamin A/C mutation in a chinese family affected with atrioventricular block as the prominent phenotype.
Xiaoyan, WU ; Qing K, WANG ; Le, GUI ; Mugen, LIU ; Xianqin, ZHANG ; Runming, JIN ; Wei, LI ; Lu, YAN ; Rong, DU ; Qiufen, WANG ; Jianfang, ZHU ; Junguo, YANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2010;30(1):103-7
Even though mutations in LMNA have been reported in patients with typical dilated cardiomyopathy (DCM) and atrioventricular block (AVB) previously, the purpose of this study was to disclose this novel genetic abnormality in one Chinese family with the atypical phenotype of progressive AVB followed by DCM with normal QRS interval. Genome-wide linkage analysis mapped the AVB gene in this family to a marker at chromosome 1q21.2, where the LMNA gene was located. Direct DNA sequence analysis revealed a heterozygous G to A transition at nucleotide 244 in exon 1 of LMNA, which resulted in an E82K mutation. The E82K mutation co-segregated with all affected individuals in the family, and was not present in 200 normal controls. Further clinical evaluation of mutation carriers showed that 5 of 6 AVB patients exhibited mild DCM with a late onset of age in the fourth and fifth decades. Ejection fractions were documented in 5 patients with DCM, but 4 showed a normal value of [Symbol: see text]50%. Echocardiography showed that atrial dilatation occurred earlier than ventricular dilatation in the patients. This study suggests that progressive AVB with normal QRS interval and accompanying DCM at later stages may represent a distinct type of DCM. The molecular mechanism by which the E82K mutation causes AVB as the prominent phenotype in DCM may be a focus of future studies.
6.Two variants in MYOC and CYP1B1 genes in a Chinese family with primary angle-closure glaucoma.
Xiaohua DAI ; Shangwu NIE ; Tie KE ; Jianping LIU ; Qing WANG ; Mugen LIU
Chinese Journal of Medical Genetics 2008;25(5):493-496
OBJECTIVETo describe the clinical and genetic characteristics of a Chinese family with primary angle-closure glaucoma (PACG).
METHODSLinkage analysis and DNA sequencing as well as single strand conformation polymorphism (SSCP) analysis were performed to identify the disease-causing mutations.
RESULTSThe Arg46Stop mutation in MYOC gene and Leu432Val in CYP1B1 gene were identified in all patients. The digenic alterations have not been identified in any same Chinese control individuals.
CONCLUSIONAuthor identified digenic mutations, Arg46Stop in MYOC gene and Leu432Val in CYP1B1 gene, in a Chinese PACG family. Author's studies suggest a possible role of MYOC and CYP1B1 in the development of PACG and support the hypothesis that PAOG and PACG may have common origin across multiple glaucoma phenotypes.
Aged ; Alleles ; Aryl Hydrocarbon Hydroxylases ; genetics ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; Cytochrome P-450 CYP1B1 ; Cytoskeletal Proteins ; genetics ; Eye Proteins ; genetics ; Female ; Genotype ; Glaucoma, Angle-Closure ; genetics ; Glycoproteins ; genetics ; Humans ; Mutation ; Pedigree ; Phenotype ; Polymorphism, Genetic
7.Analysis of USH2A gene mutation in a Chinese family affected with Usher syndrome.
Pengcheng LI ; Fei LIU ; Mingchang ZHANG ; Qiufen WANG ; Mugen LIU
Chinese Journal of Medical Genetics 2015;32(4):468-471
OBJECTIVETo investigate the disease-causing mutation in a Chinese family affected with Usher syndrome type II.
METHODSAll of the 11 members from the family underwent comprehensive ophthalmologic examination and hearing test, and their genomic DNA were isolated from venous leukocytes. PCR and direct sequencing of USH2A gene were performed for the proband. Wild type and mutant type minigene vectors containing exon 42, intron 42 and exon 43 of the USH2A gene were constructed and transfected into Hela cells by lipofectamine reagent. Reverse transcription (RT)-PCR was carried out to verify the splicing of the minigenes.
RESULTSPedigree analysis and clinical diagnosis indicated that the patients have suffered from autosomal recessive Usher syndrome type II. DNA sequencing has detected a homozygous c.8559-2A>G mutation of the USH2A gene in the proband, which has co-segregated with the disease in the family. The mutation has affected a conserved splice site in intron 42, which has led to inactivation of the splice site. Minigene experiment has confirmed the retaining of intron 42 in mature mRNA.
CONCLUSIONThe c.8559-2A>G mutation in the USH2A gene probably underlies the Usher syndrome type II in this family. The splice site mutation has resulted in abnormal splicing of USH2A pre-mRNA.
Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; China ; Extracellular Matrix Proteins ; genetics ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Pedigree ; Usher Syndromes ; genetics ; metabolism ; Young Adult
8.A novel COL4A5 splicing mutation causing Alport syndrome in a Chinese family.
Zhaohui TANG ; Yong DAI ; Zhihui WAN ; Tailan ZHAN ; Jinwang TAN ; Xiang REN ; Jingyu LIU ; Qing WANG ; Mugen LIU
Chinese Journal of Medical Genetics 2008;25(6):649-652
OBJECTIVETo identify the pathogenic mutation in a Chinese family with Alport syndrome.
METHODSBlood samples were collected from the members of the family. Direct DNA sequence analysis of the entire coding region and exon-intron boundaries of the COL4A5 gene was performed, and restriction fragment length polymorphism (RFLP) analysis was used to confirm the sequencing results and to test the mutation in all the family members and 200 controls.
RESULTSA novel splicing mutation of c.1517-1G to T in the COL4A5 gene was identified in all patients in the family. RFLP analysis did not detect this mutation in all the unaffected family members and the 200 controls.
CONCLUSIONThis data revealed a novel splicing mutation of c.1517-1G to T in the COL4A5 gene causing Alport syndrome in a Chinese family. Author's study enriched the spectrum of COL4A5 mutation associated with Alport syndrome.
Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Case-Control Studies ; Chromosomes, Human, X ; genetics ; Collagen Type IV ; genetics ; DNA Mutational Analysis ; Female ; Genetic Linkage ; Humans ; Male ; Mutation ; Nephritis, Hereditary ; genetics ; Pedigree ; Polymorphism, Restriction Fragment Length ; RNA Splicing ; genetics
9.Identification of a New Lamin A/C Mutation in a Chinese Family Affected with Atrioventricular Block as the Prominent Phenotype
WU XIAOYAN ; K.WANG QING ; GUI LE ; LIU MUGEN ; ZHANG XIANQIN ; JIN RUNMING ; LI WEI ; YAN LU ; DU RONG ; WANG QIUFEN ; ZHU JIANFANG ; YANG JUNGUO
Journal of Huazhong University of Science and Technology (Medical Sciences) 2010;30(1):103-107
Even though mutations in LMNA have been reported in patients with typical dilated cardio-myopathy(DCM)and atrioventricular block(AVB)previously,the purpose of this study was to disclose this novel genetic abnormality in one Chinese family with the atypical phenotype of progressive AVB followed by DCM with normal QRS interval.Genome-wide linkage analysis mapped the AVB gene in this family to a marker at chromosome 1q21.2,where the LMNA gene was located.Direct DNA sequence analysis revealed a heterozygous G to A transition at nucleotide 244 in exon 1 of LMNA,which resulted in an E82K mutation.The E82K mutation co-segregated with all affected individuals in the family,and was not present in 200 normal controls.Further clinical evaluation of mutation carriers showed that 5 of 6 AVB patients exhibited mild DCM with a late onset of age in the fourth and fifth decades.Ejection fractions were documented in 5 patients with DCM,but 4 showed a normal value of ≥50%.Echocardiography showed that atrial dilatation occurred earlier than ventricular dilatation in the patients.This study suggests that progressive AVB with normal QRS interval and accompanying DCM at later stages may represent a distinct type of DCM.The molecular mechanism by which the E82K mutation causes AVB as the prominent phenotype in DCM may be a focus of future studies.
10.Mechanisms of PiT2-loop7 Missense Mutations Induced Pi Dyshomeostasis.
Hao SUN ; Xuan XU ; Junyu LUO ; Tingbin MA ; Jiaming CUI ; Mugen LIU ; Bo XIONG ; Shujia ZHU ; Jing-Yu LIU
Neuroscience Bulletin 2023;39(1):57-68
PiT2 is an inorganic phosphate (Pi) transporter whose mutations are linked to primary familial brain calcification (PFBC). PiT2 mainly consists of two ProDom (PD) domains and a large intracellular loop region (loop7). The PD domains are crucial for the Pi transport, but the role of PiT2-loop7 remains unclear. In PFBC patients, mutations in PiT2-loop7 are mainly nonsense or frameshift mutations that probably cause PFBC due to C-PD1131 deletion. To date, six missense mutations have been identified in PiT2-loop7; however, the mechanisms by which these mutations cause PFBC are poorly understood. Here, we found that the p.T390A and p.S434W mutations in PiT2-loop7 decreased the Pi transport activity and cell surface levels of PiT2. Furthermore, we showed that these two mutations attenuated its membrane localization by affecting adenosine monophosphate-activated protein kinase (AMPK)- or protein kinase B (AKT)-mediated PiT2 phosphorylation. In contrast, the p.S121C and p.S601W mutations in the PD domains did not affect PiT2 phosphorylation but rather impaired its substrate-binding abilities. These results suggested that missense mutations in PiT2-loop7 can cause Pi dyshomeostasis by affecting the phosphorylation-regulated cell-surface localization of PiT2. This study helps understand the pathogenesis of PFBC caused by PiT2-loop7 missense mutations and indicates that increasing the phosphorylation levels of PiT2-loop7 could be a promising strategy for developing PFBC therapies.
Humans
;
Cell Membrane
;
Mutation, Missense
;
Phosphates/metabolism*
;
Sodium-Phosphate Cotransporter Proteins, Type III/genetics*