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OBJECTIVE@#To investigate the molecular genetic mechanism of Charcot- Marie-Tooth (CMT) disease in a pedigree.@*METHODS@#Genomic DNA was extracted from the peripheral blood of the family members of a pedigree with autosomal dominant CMT disease, and 65 candidate genes of the proband were screened using target exon capture and the next generation sequencing, and the suspicious genes were verified using Sanger sequencing. PolyPhen-2, PROVEAN and SIFT software were used to predict the function of the mutant genes, and PyMOL-1 software was used to simulate the mutant protein structure.@*RESULTS@#A heterozygous missense mutation [c.371A>G (p.Y124C)] was detected in exon 3 of gene of the proband. This heterozygous mutation was also detected in both the proband's mother and her brother, but not in her father. Multiple sequence alignment analysis showed that tyrosine at codon 124 of GDAP1 protein was highly conserved. All the 3 prediction software predicted that the mutation was harmful. Molecular structure simulation showed a weakened interaction force between the amino acid residues at codon 124 and the surrounding amino acid residues to affect the overall stability of the protein.@*CONCLUSIONS@#The mutation of gene may be related to the pathogenesis of autosomal dominant AD-CMT in this pedigree. The newly discovered c.371A>G mutation (p.Y124C) expands the mutation spectrum of gene, but further study is needed to clarify the underlying pathogenesis.

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<p><b>OBJECTIVE</b>To investigate the correlation of apolipoprotein AI (ApoAI), ApoB, ApoB/ApoAI and the severity of brain white matter lesions (WML).</p><p><b>METHODS</b>A total of 648 patients with WML confirmed by brain magnetic resonance imaging (MRI) were divided into mild WML group (=386) and moderate to severe WML group (=262) according to evaluations with the Fazekas scale. The demographic data, blood biochemical parameters and the levels of ApoAI, ApoB and ApoB/AI ratio were compared between the two groups to identify the risk factors of moderate to severe WML.</p><p><b>RESULTS</b>Univariate analysis showed that age, gender, hypertension, diabetes, coronary heart disease, previous stroke, homocysteine, HDL-C, ApoAI, and ApoB/AI ratio all differed significantly between the two groups ( < 0.05), but ApoB levels were similar between them ( > 0.05). Multivariate logistic regression analysis revealed that with ApoAI and ApoB/AI ratio as the continuous variables, after adjustment for the compounding factors, ApoB/AI ratio was an independent risk factor (OR=11.456, 95% : 3.622-36.229, < 0.001) and ApoAI was an independent protective factor for moderate to severe WML (OR=0.068, 95% : 0.018-0.262, < 0.001). With the upper quartiles of ApoAI level (1.38 g/L) and ApoB/AI ratio (0.58) as their respective cutoff values, patients with a high ApoAI level and a low ApoB/AI ratio were found to have the lowest incidence of moderate to severe WML ( < 0.001).</p><p><b>CONCLUSIONS</b>An increased ApoB/AI ratio is an independent risk factor and an increased ApoAI level is an independent protective factor for moderate to severe WML.</p>

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Objective To explore the preparation and identification of amyloid-β protein 1-42 (Aβ1-42) oligomers and their effect on in vitro cultured astrocytes in mice.Methods (1) Aβ1-42peptides were dissolved and 100 μ mol/L Aβ1-42 polypeptide was chosen as mother liquor;and then,they were incubated under different conditions (4 ℃ for 24 h,4 ℃ for 72 h,37 ℃ for 24 h and 37 ℃ for 72 h);the form of Aβ-42 was observed under electron microscope and the degrees of Aβ1-42 polymerization were detected by Western blotting.(2) Aβ1-42 oligomers of different concentrations (Aβ1-42 polypeptide as mother liquor being incubated under condition of 4 ℃ for 24 h) were added into the in vitro cultured astrocytes;CCK-8 assay was used to detect the effects ofAβ1-42 oligomers (0,0.1,0.5,1,5,10,50,and 100 μmol/L) on astrocytic viability;after 0,1,10,and 50 μmol/L Aβ1-42 oligomers treatment,immunofluorescence was employed to detect the morphological changes of astrocytes and Western blotting was used to detect the glial fibrillary acidic protein (GFAP) and aquaporin-4 (AQP4) expressions.Results (1) Different forms and degrees of polymerization of Aβ1-42 could be observed by electron microscope and Western blotting:100 μmol/L Aβ1-42 polypeptides could induce 10 nm granulated mixture of Aβ1-42 oligomers at 4 ℃ incubation for 24 h;proteins with relative molecular mass of 10 000 had decreased expression,and those of 15 000-25 000 had increased expression.(2) Twenty-four h after Aβ1-42oligomers treatment,the viability of astrocytes was increased gradually:as compared with the 0 μmol/L Aβ1-42 oligomer treatment group,the 10,50 and 100 μmol/L Aβ1-42 oligomer treatment groups had significantly increased viability of astrocytes (P＜0.05);immunofluorescent staining indicated that as compared with the 0 μmol/L Aβ1-42 oligomer treatment group,the one,10,and 50 μmol/L Aβ1-42 oligomer treatment groups had activated astrocytes:enlarged soma,increased cell processes and increased GFAP fluorescence intensity were noted;Western blotting indicated that following the increased oligomer concentrations,the protein expressions of GFAP and AQP4 increased:as compared with the 0 μmol/L Aβ1-42 oligomer treatment group,the 10 and 50 μmol/L Aβ1-42 oligomer treatment groups had significantly increased GFAP protein expression (P＜0.05);and as compared with the 0 μmol/L Aβ1-42 oligomer treatment group,the one,10,and 50 μmol/L Aβ1-42 oligomer treatment groups had significantly increased AQP4 protein expression (P＜0.05) Conclusions The Aβ1-42 oligomers could be prepared with 100 μmol/L peptide under 4 ℃ for 24 h.Aβ1-42 oligomers could activate astrocytes and up-regulate the AQP4 expression,which might be a self protective mechanism.