Project description:Charcot-Marie-Tooth 1A is a demyelinating peripheral neuropathy caused by the duplication of peripheral myelin protein 22 (PMP22), which produces muscle weakness and loss of sensation in the hands and feet. A recent case-only genome wide association study by the Inherited Neuropathy Consortium identified a strong association between variants in signal induced proliferation associated 1 like 2 (SIPA1L2) and strength of foot dorsiflexion. To validate SIPA1L2 as a candidate modifier, and to assess its potential as a therapeutic target, we engineered mice with a deletion in SIPA1L2 and crossed them to the C3-PMP22 mouse model of CMT1A. We performed neuromuscular phenotyping and identified an interaction between Sipa1l2 deletion and muscular endurance decrements assayed by wire-hang duration in C3-PMP22 mice, as well as several interactions in femoral nerve axon morphometrics such as myelin thickness. Gene expression changes suggested an involvement of Sipa1l2 in cholesterol biosynthesis, which was also implicated in C3-PMP22 mice. Though several interactions between Sipa1l2 deletion and CMT1A-associated phenotypes were identified, validating a genetic interaction, the overall effect on neuropathy was small.
Project description:We compared gene expression at ages P4 and P60 in sciatic nerve of wild type mice and mice with peripheral neuropathies caused by altered Pmp22 gene dosage (homozygous knockout or transgene) or a point mutation (Trembler).
Project description:We compared gene expression at ages P4 and P60 in sciatic nerve of wild type mice and mice with peripheral neuropathies caused by altered Pmp22 gene dosage (homozygous knockout or transgene) or a point mutation (Trembler). Keywords: parallel sample
Project description:The goal of this study was to identify deregulated genes in Schwann cells of Pmp22 transgenic rats in comparison to wildtype rats. Three timepoints in the course of peripheral nerve myelination were chosen (embryonic day [E] 21, perinatal day [P]6 and P18) in order to reveal mechanistic insight into early pathological processes of Charcot-Marie-Tooth disease 1A (CMT1A).
Project description:Here, human induced pluripotent stem cells (control-hiPSCs, CMT1A-hiPSCs, and PMP22-hiPSCs) were induced to differentiate to Schwann cells (control-SCs, CMT1A-SCs, and PMP22-SCs) through neural crest stage (control-NCSCs, CMT1A-NCSCs, and PMP22-NCSCs). We sequenced mRNA samples from Schwann cell differentiation of human pluripotent stem cells at 3 different stage to generate the gene expression profiles of these cells.
Project description:GDAP1 is a mitochondrial fission factor and mutations in GDAP1 cause Charcot-Marie-Tooth disease. Gdap1 knockout mice, mimicking genetic alterations of patients suffering from severe CMT forms, develop an age-related, hypomyelinating peripheral neuropathy. We used microarrays to determine changes in the expression profiles in the peripheral nervous system before a phenotype was detectable in the animal model (2 month of age). To seek changes in gene expression patterns of Gdap1-/- mice, we isolated motoneurons by laser dissection and took sciatic nerve lysates of two-month-old mice and purified RNA of five mice. Based on the amount and quality of the isolated RNA we selected three samples per tissue (sciatic nerve lysate and motoneruons) and genotype (GDAP1-/- or wild type). Note: the probe sets for Gdap1 lie within exon 4 and exon 6, thus no apparent loss of Gdap1 mRNA expression is present in Gdap1-/- animals.
Project description:Peripheral myelin protein 22 (PMP22) is a tetraspan integral membrane protein for which mistrafficking-causing mutations are linked to the inherited peripheral neuropathy, Charcot-Marie-Tooth disease (CMTD). Wild type (WT) PMP22 is an inefficient folder with ~20% of the protein trafficking to the plasma membrane. We discovered that N-linked glycosylation significantly limits forward trafficking of WT and disease variants of PMP22. N-glycosylation of WT PMP22 was found to occur primarily post-translationally. Glycosylation inhibition dramatically increased PMP22 trafficking efficiency. Quantitative proteomics identified novel PMP22 interacting proteins that may impact trafficking. Our results suggest that critical quality control decisions for unstable L16P PMP22 occur at earlier stages in the trafficking pathway than for the WT protein. Knock-out cell lines of likely PMP22 interactors led to the discovery that calnexin limits trafficking of stable PMP22 variants, UGGT1 promotes trafficking and RER1 limits trafficking of all PMP22 variants. This work establishes N-glycosylation as a key determinant of PMP22 retention in the ER, ultimately limiting forward surface-trafficking.
Project description:The deletion of the POZ domain of the transcription factor Miz1 leads to a late onset neuropathy with subsequent spontaneous regeneration in mice. In this study, we aim to identify genes that are involved in the development of this neuropathy. We traced first gene regulatory changes in sciatic nerve tissue from Miz1∆POZ mice to 30 days after birth. At this time point, we harvested samples of sciatic nerve tissue from several mice and performed RNAseq analysis to identify differentially expressed genes between Miz1∆POZ and wild type mice.
Project description:The goal of the experiment was to assess gene expression in sciatic nerve of Mtmr2 null mice, which is a model of the genetic neuropathy known as CMT4B1, and response to niacin treatment.
Project description:SREBF-1c is a transcription factor regulating fatty acid biosynthesis. We have charaterized the impact of the abcence of SREBF-1c on the development of peripheral neuropathy In this dataset we included expression data from dissected sciatic nerve from 10 months old SREBF-1c KO mice and relative littermates.
