Project description:Members of the CUG-BP, Elav-like family (CELF) regulate alternative splicing in the heart. In MHC-CELFdelta transgenic mice, CELF splicing activity is inhibited postnatally in heart muscle via expression of a nuclear dominant negative CELF protein under an a-myosin heavy chain promoter. MHC-CELFdelta mice develop dilated cardiomyopathy characterized by alternative splicing defects, enlarged hearts, and severe contractile dysfunction. In this study, gene expression profiles in the hearts of wild type, high- and low-expressing lines of MHC-CELFdelta mice were compared using microarrays. Gene ontology and pathway analyses identified contraction and calcium signaling as the most affected processes. Network analysis revealed that the serum response factor (SRF) network is highly affected. Downstream targets of SRF were up-regulated in MHC-CELFdelta mice compared to the wild type, suggesting an increase in SRF activity. Although SRF levels remained unchanged, known inhibitors of SRF activity were down-regulated. These results suggest a role for CELF-mediated alternative splicing in the regulation of contractile gene expression, achieved in part through modulating the activity of SRF, a key cardiac transcription factor. Microarray analysis was performed on total RNA extracted from whole hearts of three MHC-CELFdelta-10 and three MHC-CELFdelta-574 females collected at weaning (three weeks old). Three female wild type littermates from each line were used as controls (n = 6 wild type in total).
Project description:Members of the CUG-BP, Elav-like family (CELF) regulate alternative splicing in the heart. In MHC-CELFdelta transgenic mice, CELF splicing activity is inhibited postnatally in heart muscle via expression of a nuclear dominant negative CELF protein under an a-myosin heavy chain promoter. MHC-CELFdelta mice develop dilated cardiomyopathy characterized by alternative splicing defects, enlarged hearts, and severe contractile dysfunction. In this study, gene expression profiles in the hearts of wild type, high- and low-expressing lines of MHC-CELFdelta mice were compared using microarrays. Gene ontology and pathway analyses identified contraction and calcium signaling as the most affected processes. Network analysis revealed that the serum response factor (SRF) network is highly affected. Downstream targets of SRF were up-regulated in MHC-CELFdelta mice compared to the wild type, suggesting an increase in SRF activity. Although SRF levels remained unchanged, known inhibitors of SRF activity were down-regulated. These results suggest a role for CELF-mediated alternative splicing in the regulation of contractile gene expression, achieved in part through modulating the activity of SRF, a key cardiac transcription factor.
Project description:CUG-BP, Elav-like family (CELF) proteins regulate alternative splicing. In MHC-CELFdelta transgenic mice, CELF-mediated alternative splicing is disrupted in heart muscle via expression of a nuclear dominant negative CELF protein under an alpha-myosin heavy chain promoter. MHC-CELFdelta mice develop dilated cardiomyopathy and contractile dysfunction by 3 weeks of age, shortly after the transgene is activated and splicing defects appear. Cardiac function and heart size spontaneously recover with age in a low-expressing (mild) line of MHC-CELFdelta mice despite persistence of dominant negative protein expression and splicing defects, whereas there is no recovery in a higher-expressing (severe) line that also experiences early muscle death and fibrosis. In this study, we explored the basis for this functional recovery by comparing the gene expression profiles in the hearts of low- and high-expressing lines of MHC-CELFdelta mice to those of wild type littermates at 3 weeks (when cardiac dysfunction is maximal) and 24 weeks (when the low-expressing line has recovered) using microarrays. We found that differences in gene expression are greatly reduced in older animals from the low-expressing line, but were exacerbated in the high-expressing line. We did not find evidence of a new compensatory pathway being activated in the low-expressing line with age, and propose that recovery may occur due to developmental stage-specific compatibility of CELF-dependent splice variants with the changing cellular environment of cardiomyocytes. Microarray analysis was performed on total RNA extracted from whole hearts of female mice: three MHC-CELFdelta-10 (high-expressing line) and three MHC-CELFdelta-574 (low-expressing line) were collected at 3 weeks, and five MHC-CELFdelta-10 and five MHC-CELFdelta-574 were collected at 24 weeks. Two wild type mice from each line were collected at each time point (n = 4 total wild type at 3 weeks, and n = 4 total wild type at 24 weeks).
Project description:CUG-BP, Elav-like family (CELF) proteins regulate alternative splicing. In MHC-CELFdelta transgenic mice, CELF-mediated alternative splicing is disrupted in heart muscle via expression of a nuclear dominant negative CELF protein under an alpha-myosin heavy chain promoter. MHC-CELFdelta mice develop dilated cardiomyopathy and contractile dysfunction by 3 weeks of age, shortly after the transgene is activated and splicing defects appear. Cardiac function and heart size spontaneously recover with age in a low-expressing (mild) line of MHC-CELFdelta mice despite persistence of dominant negative protein expression and splicing defects, whereas there is no recovery in a higher-expressing (severe) line that also experiences early muscle death and fibrosis. In this study, we explored the basis for this functional recovery by comparing the gene expression profiles in the hearts of low- and high-expressing lines of MHC-CELFdelta mice to those of wild type littermates at 3 weeks (when cardiac dysfunction is maximal) and 24 weeks (when the low-expressing line has recovered) using microarrays. We found that differences in gene expression are greatly reduced in older animals from the low-expressing line, but were exacerbated in the high-expressing line. We did not find evidence of a new compensatory pathway being activated in the low-expressing line with age, and propose that recovery may occur due to developmental stage-specific compatibility of CELF-dependent splice variants with the changing cellular environment of cardiomyocytes.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)