Animals ; Biological Transport, Active/physiology* ; Centrioles/metabolism* ; Cilia/metabolism* ; Mice ; Mice, Mutant Strains ; N-Acetylglucosaminyltransferases/metabolism*

OBJECTIVE: To detect EXT1 and EXT2 gene mutations in two pedigrees affected with hereditary multiple exostosis (HME). METHODS: The coding regions and exon/intron boundaries of the EXT1 and EXT2 genes were analyzed by targeted next-generation sequencing (NGS). Suspected mutations were confirmed by Sanger sequencing of the probands, their family members and 200 unrelated healthy controls. Gross deletion was confirmed by quantitative PCR (qPCR) analysis and multiple ligation-dependent probe amplification (MLPA) analysis. RESULTS: Two mutations were detected in the pedigrees, which included EXT2 gene c.337_338insG mutation in pedigree 1 and deletion of entire EXT1 in pedigree 2. Analysis of sequencing data revealed that a novel heterozygous mutation (c.337_338insG) in EXT2 gene in proband 1 and his father. The same mutation was not found among healthy family members and 200 unrelated healthy controls. As shown by NGS and MLPA analysis, proband 2 carried a heterozygous deletion of entire EXT1 gene. The same deletion was also found in her mother by qPCR. CONCLUSION Mutations of the EXT1 and EXT2 genes probably underlie the HME in both pedigrees. NGS combined with Sanger sequencing, qPCR and MLPA is effective for attaining the diagnosis.
DNA Mutational Analysis ; Exostoses, Multiple Hereditary ; genetics ; Female ; Humans ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Pedigree

OBJECTIVE: To identify pathogenic variations of EXT1 and EXT2 genes in two Chinese pedigrees affected with hereditary multiple exostosis (HME). METHODS: Genomic DNA was extracted from peripheral blood samples using a phenol-chloroform method. PCR and Sanger sequencing was conducted to amplify the exons and the flanking intronic regions of the EXT1 and EXT2 genes. RESULTS: DNA sequencing has revealed a heterozygous missense variation c.812A>G (p.Tyr271Cys) in the exon 1 of EXT1 in pedigree 1, and a heterozygous frameshift variation c.1431dup (p.Ser478Leufs*43) in the exon 6 of EXT1 in the proband from pedigree 2. Both variations have co-segregated with the disease phenotype, which was also consistent with previous report. CONCLUSION Two heterozygous pathogenic variations underlying HME have been identified. The result has facilitated genetic counseling and prenatal diagnosis for the affected pedigrees.
Asian Continental Ancestry Group ; Base Sequence ; DNA Mutational Analysis ; Exostoses, Multiple Hereditary ; genetics ; pathology ; Frameshift Mutation ; Humans ; Mutation, Missense ; N-Acetylglucosaminyltransferases ; genetics ; Pedigree

OBJECTIVETo detect potential mutation of EXT1 gene in a pedigree affected with multiple osteochondroma and explore its pathogenic mechanism.

METHODSThe coding regions and their flanking sequences of the EXT1/EXT2 genes were subjected to PCR amplification and Sanger sequencing. Suspected mutations were verified by excluding possible single nucleotide polymorphisms and bioinformatics analysis. Transcripts of the EXT1 gene in the proband were analyzed by TA clone-sequencing, with its abundance compared with that of healthy controls.

RESULTSDNA sequencing has identified in the proband a novel heterozygous point mutation (c.1164+1G to A) at the 5'splice sites of intron 3 of the EXT1 gene. The same mutation was not found in the healthy controls. Bioinformatics analysis indicated that the mutation is highly conserved and can lead to skipping of exon 3 or aberrant splicing. TA clone-sequencing indicated that the numbers of transcripts with skipping of exon 3 has significantly increased in the proband (< 0.05) compared with the controls.

CONCLUSIONThe c.1164+1G to A mutation has resulted in skipping of exon 3 in a proportion of EXT1 gene transcripts. As the result, the number of transcripts with tumor suppressing function is relatively reduced and has ultimately led to the tumors.

Adult ; Base Sequence ; Child ; Exostoses, Multiple Hereditary ; genetics ; Female ; Humans ; Male ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases ; genetics ; Point Mutation ; RNA Splice Sites ; RNA Splicing

Dynamic changes of the post-translational O-GlcNAc modification (O-GlcNAcylation) are controlled by O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) and the glycoside hydrolase O-GlcNAcase (OGA) in cells. O-GlcNAcylation often occurs on serine (Ser) and threonine (Thr) residues of the specific substrate proteins via the addition of O-GlcNAc group by OGT. It has been known that O-GlcNAcylation is not only involved in many fundamental cellular processes, but also plays an important role in cancer development through various mechanisms. Recently, accumulating data reveal that O-GlcNAcylation at histones or non-histone proteins can lead to the start of the subsequent biological processes, suggesting that O-GlcNAcylation as 'protein code' or 'histone code' may provide recognition platforms or executive instructions for subsequent recruitment of proteins to carry out the specific functions. In this review, we summarize the interaction of O-GlcNAcylation and epigenetic changes, introduce recent research findings that link crosstalk between O-GlcNAcylation and epigenetic changes, and speculate on the potential coordination role of O-GlcNAcylation with epigenetic changes in intracellular biological processes.
Acetylglucosamine ; metabolism ; Animals ; Epigenesis, Genetic ; Glycoside Hydrolases ; metabolism ; Humans ; N-Acetylglucosaminyltransferases ; metabolism ; Neoplasms ; genetics ; metabolism ; Protein Processing, Post-Translational

Hereditary multiple exostoses (HME) are an autosomal dominant skeletal disease with wide variations in clinical manifestations among different ethnic groups. This study investigated the epidemiology, clinical presentations, pathogenetic features and treatment strategies of HME in mainland China. We searched and reviewed the related cases published since 1990 by searching electronic databases, namely SinoMed database, Wanfang database, CNKI, Web of Science and PubMed as well as Google search engines. A total of 1051 cases of HME (male-to-female ratio 1.5:1) were investigated and the diagnosis was made in 83% before the age of 10 years. Approximately 96% patients had a family history. Long bones, ribs, scapula and pelvis were the frequently affected sites. Most patients were asymptomatic with multiple palpable masses. Common complications included angular deformities, impingement on neighbouring tissues and impaired articular function. Chondrosarcomas transformation occurred in 2% Chinese cases. Among the cases examined, about 18% had mutations in EXT1 and 28% in EXT2. Frameshift, nonsense and missense mutations represented the majority of HME-causing mutations. Diagnosis of HME was made based on the clinical presentations and radiological documentations. Most patients needed no treatment. Surgical treatment was often directed to remove symptomatic exostoses, particularly those of suspected malignancy degeneration, and correction of skeletal deformities. This study shows some variance from current literature regarding other ethnic populations and may provide valuable baseline assessment of the natural history of HME in mainland China.
Adult ; Asian Continental Ancestry Group ; genetics ; Cell Transformation, Neoplastic ; genetics ; China ; epidemiology ; Exostoses, Multiple Hereditary ; diagnosis ; ethnology ; genetics ; Family Health ; Female ; Genetic Predisposition to Disease ; genetics ; Humans ; Male ; Membrane Proteins ; genetics ; Middle Aged ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Polymorphism, Genetic ; Prevalence ; Retrospective Studies ; Sex Factors ; Tumor Suppressor Proteins ; genetics ; Young Adult

OBJECTIVETo investigate EXT1 and EXT2 genes mutations in a family with hereditary multiple osteochondromas (HME).

METHODSA four-generation family with HME from Linyi city of Shandong Province was studied. There were 6 affected individuals among the 17 family members. Physical examination and radiographical evaluations were carried out for all family members. Genomic DNA was extracted from peripheral venous blood and the samples were subjected to mutation screening by PCR of the coding regions of EXT1 and EXT2 genes.

RESULTSThe family has featured an autosomal dominant inheritance pattern. Sequencing of the EXT1 and EXT2 genes suggested the causative gene in this family was in linkage with the second exon of EXT2. A c.244delG mutation was detected, which has resulted in a frameshift mutation p.Asp81IlefsX30. The mutation was found in all of the 6 affected individuals but not in normal family members. And the mutation has co-segregated with the phenotype.

CONCLUSIONThe mutation c.244delG in the EXT2 gene is the probably the cause of the disease in this family.

Adult ; Base Sequence ; Child, Preschool ; DNA Mutational Analysis ; Exons ; Exostoses, Multiple Hereditary ; genetics ; Female ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases ; genetics ; Pedigree ; Point Mutation ; Young Adult

OBJECTIVEHereditary multiple exostoses (HME) is an autosomal dominant monogenic disorder of paraplasia ossium. Mutations in EXT1 and EXT2 have been suggested to be responsible for over 70% of HME cases. This study aimed to analyze the clinical features and pathogenic mutations in a Chinese family with HME (6 patients in 24 members of 3 generations) and to review the relative literature regarding mutations in EXT1 and EXT2 in the Chinese population.

METHODSClinical pedigree dada from a Chinese family of HME were collected and analysed. EXT gene mutations in this pedigree assessed by PCR and sequencing. Pubmed and Wanfang (a Chinese database) were searched for the literature related to gene mutations in Chinese HME patients.

RESULTSIn the pedigree analyzed, the age of onset of HME was becoming younger, the disease was becoming more severe, and the number of osteochondromas was increasing, in successive generations. A splicing mutation IVS5+1G>A, first identified in Chinese population, was found in all diseased members of this pedigree. According the currently available literature, EXT1 and EXT2 mutations have been detected in 29% (26/90) and 43% (39/90) Chinese families with HME.

CONCLUSIONSHME starts earlier and becomes more severe and extensive with each successive generation in members of the pedigree analyzed. A splicing mutation, IVS5+1G>A, of EXT1, first identified in Chinese population, may be responsible for HME in the studied pedigree. EXT1 and EXT2 mutation rates may be different between the Chinese and Western populations.

Adolescent ; Adult ; Aged ; Alternative Splicing ; Exostoses, Multiple Hereditary ; genetics ; Female ; Humans ; Male ; Middle Aged ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Pedigree

OBJECTIVETo screen for potential mutations in an ethnic Han Chinese family from Shanxi with hereditary multiple exostoses.

METHODSPolymerase chain reaction and DNA sequencing were used to screen potential mutations in EXT1 and EXT2 genes.

RESULTSFor EXT1 gene, two synonymous mutations (P477P and E587E), three intronic mutations (c.1537 -48A>G, c.1721 +203A>G and c.1722 -103C>G) were detected. For EXT2 gene, five intronic mutations (c.-29 -148A>T, c.1080 -18T>A, c.1336 -93C>T, c.1526 -166C>T, and c.1526 -195C>T) were identified. Among these, EXT1 P477P, EXT1 E587E and EXT2 c.1080 -18T>A are polymorphisms listed by Multiple Osteochondroma Mutation Database, whilst the other 7 sites have not been reported.

CONCLUSIONNo mutations have been found among all exons of the EXT1 and EXT2 genes in this family. Linkage analysis is necessary for identifying the cause of this disease.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; China ; Exons ; Exostoses, Multiple Hereditary ; diagnosis ; genetics ; Female ; Genotype ; Humans ; Introns ; Male ; Middle Aged ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Young Adult

OBJECTIVETo study the effects of Xixin decoction (XXD) on O-GlcNAc transferase (OGT) and O-GlcNAc glycosidase in O-GlcNAc glycosylation of tau proteins in the brain of rats with sporadic Alzheimer's disease (SAD) and explore the possible mechanism.

METHODSMale SD rats were randomly divided into sham-operated group, model group, donepezil group, and low-, moderate-, and high-dose XXD groups. After treatment and behavioral test, the rats were sacrificed for detecting the expressions of OGT and O-GlcNAc glycosidase in the brain using immunohistochemistry and Western blotting.

RESULTSXXD significantly enhanced the expressions of OGT in the hippocampus of SAD rats and lowered the expression of O-GlcNAc glycosidase (P<0.05 or 0.01). OGT and O-GlcNAc glycosidase expressions showed no significant differences between the model group and donepezil group (P>0.05).

CONCLUSIONXXD can regulate the expression of OGT and O-GlcNAc glycosidase to enhance O-GlcNAc glycosylation of tau proteins in the hippocampus of SAD rats.

Acetylglucosaminidase ; metabolism ; Alzheimer Disease ; chemically induced ; enzymology ; metabolism ; Animals ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Glycosylation ; Hippocampus ; enzymology ; metabolism ; Male ; N-Acetylglucosaminyltransferases ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Streptozocin ; tau Proteins ; metabolism