Objective To investigate the mutations of mitochondrial genome in a pedigree with suspected maternally inherited diabetes and deafness and to explore the correlations between the mutations and clinical features. Meth...Objective To investigate the mutations of mitochondrial genome in a pedigree with suspected maternally inherited diabetes and deafness and to explore the correlations between the mutations and clinical features. Methods Genomic DNA was isolated from blood leucocytes of each member of the pedigree. The mitochondrial genome was amplified with 24-pair primers that could cover the entire mitochondrial DNA. Direct sequencing of PCR products was used to identify any mitochondrial DNA mutations. Results Family members on the maternal side all harbored the tRNA^Lcu（UUR） A3243G mutation. The paternal side family members did not have the mutation. The age-of-onset of diabetes of the 4 maternal side family members was 15, 41, 44, and 65 years old, and their corresponding heteroplasmy level of the mutation was 34.5%, 14.9%, 14.6%, and 5.9%, respectively. The age-of-onset of diabetes and heteroplasmy level of A3243G mutation were negatively correlated with a correlation coefficient of -0.980（P=0.02）. Meanwhile, patient with high heteroplasmy level of A3243G mutation had relatively low severity of disease. Moreover, 6 reported polymorphisms and 2 new variants were found. Conclusions The main cause of diabetes in this pedigree is the tRNA^Lcu（UUR） A3243G mutation. However, other gene variants may contribute to its pathogenicity. The heteroplasmy level of the tRNA^Lcu（UUR） A3243G mutation is positively associated with earlier age-of-onset and increasing severity of diabetes.展开更多
Mitochondrion plays the key functions in mammalian cells. It is believed that mitochondrion exerts the common biologic functions in many tissues, but also performs some specific functions correspondent with tissues wh...Mitochondrion plays the key functions in mammalian cells. It is believed that mitochondrion exerts the common biologic functions in many tissues, but also performs some specific functions correspondent with tissues where it is localized. To identify the tissue-specific mitochondrial proteins, we carried out a systematic survey towards mitochondrial proteins in the tissues of C57BL/6J mouse, such as liver, kidney and heart. The mitochondrial proteins were separated by 2DE and identified by MALDI-TOF/TOF MS. Total of 87 unique proteins were identified as the tissue-specific ones, and some representatives were further verified through ICPL quantification and Western blot. Because these issue-specific proteins are coded from nuclear genes, real-time PCR was employed to examine the mRNA status of six typical genes found in the tissues.With combining of the expression data and the co-localization images obtained from confocal microscope, we came to the conclusion that the tissue-specifically mitochondrial proteins were widely distributed among the mouse tissues. Our investigation, therefore, indeed provides a solid base to further explore the biological significance of the mitochondrial proteins with tissue-orientation.展开更多
文摘Objective To investigate the mutations of mitochondrial genome in a pedigree with suspected maternally inherited diabetes and deafness and to explore the correlations between the mutations and clinical features. Methods Genomic DNA was isolated from blood leucocytes of each member of the pedigree. The mitochondrial genome was amplified with 24-pair primers that could cover the entire mitochondrial DNA. Direct sequencing of PCR products was used to identify any mitochondrial DNA mutations. Results Family members on the maternal side all harbored the tRNA^Lcu（UUR） A3243G mutation. The paternal side family members did not have the mutation. The age-of-onset of diabetes of the 4 maternal side family members was 15, 41, 44, and 65 years old, and their corresponding heteroplasmy level of the mutation was 34.5%, 14.9%, 14.6%, and 5.9%, respectively. The age-of-onset of diabetes and heteroplasmy level of A3243G mutation were negatively correlated with a correlation coefficient of -0.980（P=0.02）. Meanwhile, patient with high heteroplasmy level of A3243G mutation had relatively low severity of disease. Moreover, 6 reported polymorphisms and 2 new variants were found. Conclusions The main cause of diabetes in this pedigree is the tRNA^Lcu（UUR） A3243G mutation. However, other gene variants may contribute to its pathogenicity. The heteroplasmy level of the tRNA^Lcu（UUR） A3243G mutation is positively associated with earlier age-of-onset and increasing severity of diabetes.
基金supported by the National Natural Science Foundation of China (Grant No. 30700378)National High Technology Research and Development Program of China (Grant No. 2006AA02A308)
文摘Mitochondrion plays the key functions in mammalian cells. It is believed that mitochondrion exerts the common biologic functions in many tissues, but also performs some specific functions correspondent with tissues where it is localized. To identify the tissue-specific mitochondrial proteins, we carried out a systematic survey towards mitochondrial proteins in the tissues of C57BL/6J mouse, such as liver, kidney and heart. The mitochondrial proteins were separated by 2DE and identified by MALDI-TOF/TOF MS. Total of 87 unique proteins were identified as the tissue-specific ones, and some representatives were further verified through ICPL quantification and Western blot. Because these issue-specific proteins are coded from nuclear genes, real-time PCR was employed to examine the mRNA status of six typical genes found in the tissues.With combining of the expression data and the co-localization images obtained from confocal microscope, we came to the conclusion that the tissue-specifically mitochondrial proteins were widely distributed among the mouse tissues. Our investigation, therefore, indeed provides a solid base to further explore the biological significance of the mitochondrial proteins with tissue-orientation.
