Project description:Neurofibromatosis type 1 (NF1) is a multi-system disease caused by mutations in the NF1 gene encoding a Ras-GAP protein, neurofibromin, which negatively regulates Ras signalling. Besides neuroectodermal malformations and tumours, the skeletal system is often affected (e.g. scoliosis and long bone dysplasia), demonstrating the importance of neurofibromin for development and maintenance of the musculoskeletal system. Here we focus on the role of neurofibromin in skeletal muscle development. Nf1 gene inactivation in the early limb bud mesenchyme using Prx1-cre (Nf1Prx1) resulted in muscle dystrophy characterised by fibrosis, reduced number of muscle fibres, and reduced muscle force. To gain insight into the molecular changes of the observed muscle dystrophy and fibrosis and to compare these with other known muscle dystrophies, we performed transcriptional profiling of the entire triceps muscles of threemonth-old wild type (wt) and mutant animals using Affymetrix high-density microrrays. We analyzed triceps muscles from 4 three-month-old wt controls and 4 three-month-old Nf1Prx1 mice using the Affymetrix Mouse Gene 1.0 ST platform. Array data was processed by the Affymetrix Exon Array Computational Tool. RNA isolated from each animal was hybridized to a separate microarray.
Project description:Neurofibromatosis type 1 (NF1) is a multi-system disease caused by mutations in the NF1 gene encoding a Ras-GAP protein, neurofibromin, which negatively regulates Ras signalling. Besides neuroectodermal malformations and tumours, the skeletal system is often affected (e.g. scoliosis and long bone dysplasia), demonstrating the importance of neurofibromin for development and maintenance of the musculoskeletal system. Here we focus on the role of neurofibromin in skeletal muscle development. Nf1 gene inactivation in the early limb bud mesenchyme using Prx1-cre (Nf1Prx1) resulted in muscle dystrophy characterised by fibrosis, reduced number of muscle fibres, and reduced muscle force. To gain insight into the molecular changes of the observed muscle dystrophy and fibrosis and to compare these with other known muscle dystrophies, we performed transcriptional profiling of the entire triceps muscles of threemonth-old wild type (wt) and mutant animals using Affymetrix high-density microrrays.
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)
Project description:Purpose: To study Nf1 regulated pathways in controlling juvenile satellite cells quiescence induction. Methods: We sequenced total mRNAs isolated from juvenile satellite cells FACS sorted from postnatal day 7 Control (Nf1flox/+ Myf5Cre+) and KO (Nf1flox/flox Myf5Cre+) mouse hindlimb skeletal muscle. Results: Our study suggests that Nf1 is required for maintaining the balance between quiescence induction and amplification / differentiation in the postnatal MP pool. Conclusions: The tumor suppressor Nf1 maintains the myogenic progenitor (MP) pool during postnatal muscle development.
Project description:Background Neurofibromatosis type 1 (NF1) is a multi-organ disease caused by mutations in Neurofibromin (NF1). Amongst other features, NF1 patients frequently show reduced muscle mass and strength, impairing patients’ mobility and increasing the risk of fall. The role of Nf1 in muscle and the cause for the NF1-associated myopathy is mostly unknown. Methods To dissect the function of Nf1 in muscle, we created muscle-specific knockout mouse models for Nf1, inactivating Nf1 in the prenatal myogenic lineage either under the Lbx1 promoter or under the Myf5 promoter. Mice were analyzed during pre-and postnatal myogenesis and muscle growth. Results Nf1Lbx1 and Nf1Myf5 animals showed only mild defects in prenatal myogenesis. Nf1Lbx1 animals were perinatally lethal, while Nf1Myf5 animals survived up to approx. 25 weeks. Nf1Myf5 animals showed decreased postnatal growth, reduced muscle size, and fast fiber atrophy. Proteome and transcriptome analysis of muscle tissue indicated decreased protein synthesis and increased proteasomal degradation, and decreased glycolytic and increased oxidative activity in muscle tissue. Real-time respirometry demonstrated enhanced oxidative metabolism in Nf1Myf5 muscles concomitant to a fiber type shift from type 2B to type 2A and type 1. Nf1Myf5 muscles showed hallmarks of mild oxidative stress and increased activation of AMPK indicating an energy deficit, increased expression of atrogenes and decreased activation of mTORC1. Proteome and transcriptome analysis indicated that oxidative fibers mainly relied on fatty acid catabolism. Inline, Nf1Myf5 animals showed a drastic reduction of white, but not brown, adipose tissue. Conclusions Our results demonstrate a cell-autonomous role for Nf1 in myogenic cells during postnatal muscle growth required for metabolic and proteostatic homeostasis. Furthermore, Nf1 deficiency in muscle leads to cross-tissue communication and mobilization of lipid reserves.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.