Project description:The molecular basis of CNS myelin regeneration (remyelination) is poorly understood. Here we generate a comprehensive transcriptional profile of the separate stages of spontaneous remyelination following focal demyelination in the rat CNS. White matter tracts in the rat caudal cerebellar peduncles were focally demyelinated using 0.1% ethidium bromide, the lesions were isolated using laser capture microdissection at 5, 14 and 28 days postlesion, followed by RNA extraction and Illumina beadarray analysis of differentially expressed transcripts. We found transcripts encoding retinoid acid receptor RXR-gamma is highly differentially expressed during remyelination, and that oligodendrocyte lineage cells express RXR-gamma in rat tissues undergoing remyelination and in active and remyelinated MS lesions. RXR-gamma knockdown by RNA interference or RXR-specific antagonists severely inhibit oligodendrocyte differentiation in culture. In RXR-gamma deficient mice, adult oligodendrocyte precursor cells efficiently repopulate lesions following demyelination, but display delayed differentiation into mature oligodendrocytes. Administration of the RXR agonist 9-cis-retinoic acid to demyelinated cerebellar slice cultures and to aged rats following demyelination results in more remyelinated axons. RXR-gamma is therefore a positive regulator of endogenous oligodendrocyte precursor cell differentiation and remyelination, and may be a pharmacological target for CNS regenerative therapy. 9 Samples analysed, 3 different time points each with 3 biological replicates.
Project description:The molecular basis of CNS myelin regeneration (remyelination) is poorly understood. Here we generate a comprehensive transcriptional profile of the separate stages of spontaneous remyelination following focal demyelination in the rat CNS. White matter tracts in the rat caudal cerebellar peduncles were focally demyelinated using 0.1% ethidium bromide, the lesions were isolated using laser capture microdissection at 5, 14 and 28 days postlesion, followed by RNA extraction and Illumina beadarray analysis of differentially expressed transcripts. We found transcripts encoding retinoid acid receptor RXR-gamma is highly differentially expressed during remyelination, and that oligodendrocyte lineage cells express RXR-gamma in rat tissues undergoing remyelination and in active and remyelinated MS lesions. RXR-gamma knockdown by RNA interference or RXR-specific antagonists severely inhibit oligodendrocyte differentiation in culture. In RXR-gamma deficient mice, adult oligodendrocyte precursor cells efficiently repopulate lesions following demyelination, but display delayed differentiation into mature oligodendrocytes. Administration of the RXR agonist 9-cis-retinoic acid to demyelinated cerebellar slice cultures and to aged rats following demyelination results in more remyelinated axons. RXR-gamma is therefore a positive regulator of endogenous oligodendrocyte precursor cell differentiation and remyelination, and may be a pharmacological target for CNS regenerative therapy.
Project description:The efficiency of central nervous system (CNS) remyelination declines with age. This is in part due to an age-associated decline in the phagocytic removal of myelin debris, which contains inhibitors of oligodendrocyte progenitor cell differentiation. In this study we show that expression of genes involved in the retinoid X receptor (RXR) pathway are decreased with aging in myelin-phagocytosing cells. Loss of RXR function in young macrophages mimics aging by delaying remyelination after experimentally-induced demyelination, while RXR agonists partially restore myelin debris phagocytosis in aged macrophages. The FDA-approved RXR agonist bexarotene, when used in concentrations achievable in human subjects, caused a reversion of the gene expression profile in aging human monocytes to a more youthful profile. These results reveal the RXR pathway as a positive regulator of myelin debris clearance and a key player in the age-related decline in remyelination that may be targeted by available or newly-developed therapeutics. 24 Human CD14+ monocyte-sorted PBMC samples representing 4 Healthy Volunteers (HV) and 4 Multiple Sclerosis (MS) patients under 3 different treatment conditions. Condition 1 = (-) Phagocystosis (-) Bexarotene. Condition 2 = (+) Phagocystosis (-) Bexarotene. Condition 3 = (+) Phagocystosis (+) Bexarotene.
Project description:Chromatin Remodeler CHD7 mutated in CHARGE Syndrome Interacts with Sox10 to Regulate Timing of CNS Myelination and Remyelination [ChIP-seq]
Project description:Remyelinating substances could be an essential supplement to immunomodulatory medications, optimizing the treatment of multiple sclerosis (MS) patients. Fingolimod is a sphingosine-1-phosphate receptor (S1PR) modulator and crosses the blood-brain barrier. Central nervous system (CNS) cells express S1PRs, and Fingolimod could theoretically improve CNS remyelination and be neuroprotective per se, but data are inconsistent. We used the cuprizone model for investigating the effect of fingolimod on remyelination and axonal damage by Immunohistochemistry and quantitative mass spectrometry. After three weeks of remyelination, fingolimod-treated mice had more mature oligodendrocytes in the secondary motor cortex than the placebo group. However, fingolimod did not at any time point affect remyelination or axonal damage. We conclude that fingolimod does not promote remyelination or protect against axonal injury or loss after cuprizone exposure.
Project description:The Norway rat has important impacts on our life. They are amongst the most used research subjects, resulting in ground-breaking advances. At the same time, wild rats live in close association with us, leading to various adverse interactions. In face of this relevance, it is surprising how little is known about their natural behaviour. While recent laboratory studies revealed their complex social skills, little is known about their social behaviour in the wild. An integration of these different scientific approaches is crucial to understand their social life, which will enable us to design more valid research paradigms, develop more effective management strategies, and to provide better welfare standards. Hence, I first summarise the literature on their natural social behaviour. Second, I provide an overview of recent developments concerning their social cognition. Third, I illustrate why an integration of these areas would be beneficial to optimise our interactions with them.
Project description:BackgroundMurine kobuviruses (MuKV) are newly recognized picornaviruses first detected in murine rodents in the USA in 2011. Little information on MuKV epidemiology in murine rodents is available. Therefore, we conducted a survey of the prevalence and genomic characteristics of rat kobuvirus in Guangdong, China.ResultsFecal samples from 223 rats (Rattus norvegicus) were collected from Guangdong and kobuviruses were detected in 12.6% (28) of samples. Phylogenetic analysis based on partial 3D and complete VP1 sequence regions showed that rat kobuvirus obtained in this study were genetically closely related to those of rat/mouse kobuvirus reported in other geographical areas. Two near full-length rat kobuvirus genomes (MM33, GZ85) were acquired and phylogenetic analysis of these revealed that they shared very high nucleotide/amino acids identity with one another (95.4%/99.4%) and a sewage-derived sequence (86.9%/93.5% and 87.5%/93.7%, respectively). Comparison with original Aichivirus A strains, such human kobuvirus, revealed amino acid identity values of approximately 80%.ConclusionOur findings indicate that rat kobuvirus have distinctive genetic characteristics from other Aichivirus A viruses. Additionally, rat kobuvirus may spread via sewage.