Repair of injured muscle involves repair of injured myofibers through the involvement of dysferlin and its interacting partners, including annexin. Studies with mice and patients have established that dysferlin deficit leads to chronic inflammation and adipogenic replacement of the diseased muscle. However, longitudinal analysis of annexin deficit on muscle pathology and function is lacking. Here we show that unlike annexin A1, but similar to dysferlin, lack of annexin A2 (AnxA2) causes poor myofiber repair and progressive weakening with age. However, unlike dysferlin-deficient muscle, AnxA2-deficient muscles do not exhibit chronic inflammation or adipogenic replacement. Deletion of AnxA2 in dysferlin deficient mice reduces inflammation, adipogenic replacement, and loss in muscle function caused by dysferlin deficit. These results show that: a) AnxA2 facilitates myofiber repair, b) chronic inflammation and adipogenic replacement of dysferlinopathic muscle requires AnxA2, and c) inhibiting AnxA2-mediated inflammation is a novel therapeutic avenue for dysferlinopathy.
Annexin A2 links poor myofiber repair with inflammation and adipogenic replacement of the injured muscle.
Age, Specimen part
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Transcriptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure.
Sex, Specimen part
View SamplesGlyphosate-based herbicides (GBH) are the major pesticides used worldwide. Converging evidence suggests that GBH residues pose a particular risk to the kidneys and liver. However, the existence of biological effects with negative health implications at low environmentally relevant doses remains unresolved. A previous investigation addressed this issue, by conducting a 2-year feeding study, which included 10 female Sprague Dawley rats administered via drinking water with 0.1 ppb of a major Roundup formulation (50 ng/L glyphosate equivalent dilution). Hepatorenal toxicities, as well as urine and blood biochemistry disturbances at the 15th month of age were observed. In an effort to obtain molecular mechanistic insight into the underlying causes of these pathologies, we have carried out a transcriptome microarray analysis of the liver and kidneys from these same animals. The expression of 4224 and 4447 genes were found to be disturbed respectively in liver and kidney (p<0.01, q<0.08, fold change >1.1). Among the 1319 genes whose expression was altered in both tissues, 3 functional categories were over-represented. First, genes involved in mRNA splicing and small nucleolar RNA were mostly upregulated, suggesting disruption of normal spliceosome activity. Electron microscopic analysis of hepatocytes confirmed nucleolar structural disruption. Second, genes controlling chromatin structure (especially histone-lysine N-methyltransferases) were mostly upregulated. Third, genes related to respiratory chain complex I and the tricarboxylic acid cycle were mostly downregulated. The transcription factor networks that can account for these disruptions were centered on CREB1, ESR1, YY1, c-Myc and Oct3/4 activity, which are known to closely cooperate in the regulation of gene expression after hormonal stimulation. The analysis of pathways and toxicity processes showed that these disturbances in gene expression were representative of fibrosis, necrosis, phospholipidosis, mitochondrial membrane dysfunction and ischemia, which correlate with the pathologies observed at an anatomical and histological level. Our results suggest that new studies incorporating testing principles from endocrinology and developmental epigenetics need to be performed to investigate potential consequences of exposure to low dose, environmental levels of GBH and glyphosate.
Transcriptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure.
Sex, Specimen part
View SamplesGlyphosate-based herbicides (GBH) are the major pesticides used worldwide. Converging evidence suggests that GBH residues pose a particular risk to the kidneys and liver. However, the existence of biological effects with negative health implications at low environmentally relevant doses remains unresolved. A previous investigation addressed this issue, by conducting a 2-year feeding study, which included 10 female Sprague Dawley rats administered via drinking water with 0.1 ppb of a major Roundup formulation (50 ng/L glyphosate equivalent dilution). Hepatorenal toxicities, as well as urine and blood biochemistry disturbances at the 15th month of age were observed. In an effort to obtain molecular mechanistic insight into the underlying causes of these pathologies, we have carried out a transcriptome microarray analysis of the liver and kidneys from these same animals. The expression of 4224 and 4447 genes were found to be disturbed respectively in liver and kidney (p<0.01, q<0.08, fold change >1.1). Among the 1319 genes whose expression was altered in both tissues, 3 functional categories were over-represented. First, genes involved in mRNA splicing and small nucleolar RNA were mostly upregulated, suggesting disruption of normal spliceosome activity. Electron microscopic analysis of hepatocytes confirmed nucleolar structural disruption. Second, genes controlling chromatin structure (especially histone-lysine N-methyltransferases) were mostly upregulated. Third, genes related to respiratory chain complex I and the tricarboxylic acid cycle were mostly downregulated. The transcription factor networks that can account for these disruptions were centered on CREB1, ESR1, YY1, c-Myc and Oct3/4 activity, which are known to closely cooperate in the regulation of gene expression after hormonal stimulation. The analysis of pathways and toxicity processes showed that these disturbances in gene expression were representative of fibrosis, necrosis, phospholipidosis, mitochondrial membrane dysfunction and ischemia, which correlate with the pathologies observed at an anatomical and histological level. Our results suggest that new studies incorporating testing principles from endocrinology and developmental epigenetics need to be performed to investigate potential consequences of exposure to low dose, environmental levels of GBH and glyphosate.
Transcriptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure.
Sex, Specimen part
View SamplesWe analyzed the generation of mouse gliomas following the overexpression of PDGF-B in embryonic neural progenitors. Comparison of our microarray data, with published gene expression data sets for many different murine neural cell types, revealed a closest relationship between our tumor cells and oligodendrocyte progenitor cells, confirming definitively that PDGF-B-induced gliomas are pure oligodendrogliomas.
PDGF-B induces a homogeneous class of oligodendrogliomas from embryonic neural progenitors.
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Progression from low- to high-grade in a glioblastoma model reveals the pivotal role of immunoediting.
Specimen part
View SamplesThe different phases of tumor immunoediting in vivo were dissected thanks to a murine model of glioma induced by PDGF-B overexpression. We show that low-grade gliomas are highly immunostimulatory and that the adaptive immune system prevents the development of secondary tumor in syngeneic mice. During tumor progression, glioma cells downregulate immunostimulatory genes and the immune infiltrate becomes pro-tumorigenic. We showed that glioma cells are able to progress towards a high-grade phenotype even in immunodeficient mice, albeit more slowly and this progression invariably requires a downregulation of immunostimulatory genes.
Progression from low- to high-grade in a glioblastoma model reveals the pivotal role of immunoediting.
Specimen part
View SamplesThe different phases of tumor immunoediting in vivo were dissected thanks to a murine model of glioma induced by PDGF-B overexpression. We show that low-grade gliomas are highly immunostimulatory and that the adaptive immune system prevents the development of secondary tumor in syngeneic mice. During tumor progression, glioma cells downregulate immunostimulatory genes and the immune infiltrate becomes pro-tumorigenic.
Progression from low- to high-grade in a glioblastoma model reveals the pivotal role of immunoediting.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Jarid1b targets genes regulating development and is involved in neural differentiation.
Specimen part
View SamplesThe H3K4me2/3 histone demethylase Jarid1b (Kdm5b/Plu1) is dispensable for embryonic stem cell (ESC) self-renewal, but essential for ESC differentiation along the neural lineage. During neural differentiation, Jarid1b depleted ESCs fail to efficiently silence lineage-inappropriate genes, specifically stem and germ cell genes. Our results delineate an essential role for Jarid1b-mediated transcriptional control during ESC differentiation.
Jarid1b targets genes regulating development and is involved in neural differentiation.
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