Gene expression profiling in equine polysaccharide storage myopathy revealed inflammation, glycogenesis inhibition, hypoxia and mitochondrial dysfunctions

<p>Abstract</p> <p>Background</p> <p>Several cases of myopathies have been observed in the horse Norman Cob breed. Muscle histology examinations revealed that some families suffer from a polysaccharide storage myopathy (PSSM). It is assumed that a gene expression signature related to PSSM should be observed at the transcriptional level because the glycogen storage disease could also be linked to other dysfunctions in gene regulation. Thus, the functional genomic approach could be conducted in order to provide new knowledge about the metabolic disorders related to PSSM. We propose exploring the PSSM muscle fiber metabolic disorders by measuring gene expression in relationship with the histological phenotype.</p> <p>Results</p> <p>Genotypying analysis of GYS1 mutation revealed 2 homozygous (AA) and 5 heterozygous (GA) PSSM horses. In the PSSM muscles, histological data revealed PAS positive amylase resistant abnormal polysaccharides, inflammation, necrosis, and lipomatosis and active regeneration of fibers. Ultrastructural evaluation revealed a decrease of mitochondrial number and structural disorders. Extensive accumulation of an abnormal polysaccharide displaced and partially replaced mitochondria and myofibrils. The severity of the disease was higher in the two homozygous PSSM horses.</p> <p>Gene expression analysis revealed 129 genes significantly modulated (p < 0.05). The following genes were up-regulated over 2 fold: IL18, CTSS, LUM, CD44, FN1, GST01. The most down-regulated genes were the following: mitochondrial tRNA, SLC2A2, PRKCα, VEGFα. Data mining analysis showed that protein synthesis, apoptosis, cellular movement, growth and proliferation were the main cellular functions significantly associated with the modulated genes (p < 0.05). Several up-regulated genes, especially IL18, revealed a severe muscular inflammation in PSSM muscles. The up-regulation of glycogen synthase kinase-3 (GSK3β) under its active form could be responsible for glycogen synthase (GYS1) inhibition and hypoxia-inducible factor (HIF1α) destabilization.</p> <p>Conclusion</p> <p>The main disorders observed in PSSM muscles could be related to mitochondrial dysfunctions, glycogenesis inhibition and the chronic hypoxia of the PSSM muscles.</p

Multiphotonic and Harmonic generation microscopy: an attractive label free imaging and non-destructive observation of collagenic and adipose tissues in pathological muscle context

Second harmonic (SHG) and third harmonic generation (THG) provide powerful tools for collagenic and adipose tissueimaging respectively in unstained section. These properties due to the multiphotonic excitation represent very promising approach to explore the state of various degenerative diseases associated with abnormal fibrotic and fat tissue. In this report, we use SHG/THG to explore the fibrotic and fat tissue in muscular dystrophy context using rat and dog model. By comparison with classical used immunolabeling dedicated to collagen, we confirmed that SHG microscopy has strong potentiality to follow the fibrosis content in the disease. We also demonstrated that THG can be used to follow the distribution of lipid bodies in cells and dystrophic tissue. Thanks to these properties, the combination of fluorescence and harmonic signals represent a promising way to monitor the course of the neuro muscular diseases as well as the efficacy of therapeutic strategies

Characterization of an avian lung epithelial cell line.

International audienc

Implication des macrophages dans l'infection et la persistance du virus du Chikungunya dans un modèle expérimental simien

National audienc

Hypoxia exerts differential effects on the chondrogenic and osteogenic differentiation of human adipose-derived mesenchymal stem cells

International audienc

A novel chicken lung epithelial cell line: Characterization and response to low pathogenicity avian influenza virus

Chantier qualité GAAvian influenza virus (AIV) infections of the chicken occur via the respiratory route. Unlike ducks which are considered as a natural AIV reservoir, chickens are highly susceptible to AIV infections and do not possess the RIG-I pattern recognition receptor involved in triggering the antiviral interferon response. To study the chicken innate immune response to AIV in the respiratory tract, we established an epithelial cell line (CLEC213) from lung explants of white leghorn chickens. CLEC213 cells exhibited a polyhedral morphology and formed cohesive clusters bound through tight junctions as assessed by electron microscopy. Expression of E-cadherin but not vimentin could be detected as expected for cells of epithelial origin. In addition, CLEC213 cells showed characteristics similar to those of mammalian type II pneumocytes, including the presence of intracytoplasmic vacuoles filled with a mucopolysaccharide material, alkaline phosphatase activity, transcription of chicken lung collectins genes (cLL and SPA), and some intracytoplasmic lamellar-like bodies. CLEC213 cells showed a constitutive expression level of TLR3 and TLR4 and were responsive to stimulation with the respective agonists, poly (I:C) and LPS: between 4 h and 24 h after treatment, a strong increase in the expression of IFN-α, IFN-β and IL-8 genes could be detected. Furthermore, CLEC213 cells supported efficient growth of the low pathogenicity avian influenza virus H6N2 (A/duck/France/05057a/2005) in the presence or the absence of trypsin in the culture media. At 4 h post-infection, the H6N2 virus induced highly elevated levels of expression of IFN-α and IL-8, moderately elevated levels of LITAF, TGF-β4 and CCL5. However, an increase of IFN-β gene expression could not be detected in response to AIV infection. In conclusion, like mammalian type II pneumocytes, CLEC213 are able to mount a robust cytokine and chemokine immune response to microbial patterns and viral infection. We hypothesize that they could derive from lung atrial granular cells. The involvement of such type of lung epithelial cells in the respiratory tract defence of the chicken can thus be further studied

Lymphocytic insulitis in a dog with juvenile diabetes mellitus

International audienc

Formula-derived advanced glycation end products are involved in the development of long-term inflammation and oxidative stress in kidney of IUGR piglets.

SCOPE:Formula-derived dietary advanced glycation end products (AGEs) may promote programming of inflammation and oxidative stress in the kidney of intrauterine growth retardation (IUGR) piglets.METHODS AND RESULTS:IUGR piglets received either a low temperature heated formula (n = 8) or a high temperature heated formula (HHF: n = 8) or suckled naturally for 3 wk postnatally. Then they were fed with normal ad libitum regular diet. N(ε)-carboxymethyllysine (CML) was measured in plasma, feces, and formula by HPLC/MS-MS. CML was detected by immunofluorescence in kidney cells. Target renin-angiotensin-apoptotic, pro-inflammatory genes-p62 NF-κB, and soluble receptor of AGE (sRAGE) levels were quantified. Compared with that in controls, free CML and plasma urea increased significantly in the HHF-fed group at PND36 (p < 0.05). CML was detected in the nuclei of renal tubular cells of formula-fed piglets but not in suckled ones. This presence of CML was associated with the activation of the soluble receptor of AGE. AT1, AT2, caspase 3, caspase 8, NF-κB, p62 NF-κB, and total protein oxidation in kidney were higher in HHF-fed group as compared to LHF-fed group (p < 0.05).CONCLUSION:Food processes aimed at reducing the concentration of AGEs in infant formula are urgently needed and may be therapeutically relevant for premature and/or IUGR babies

Intra-muscular distribution of dystrophin positive fibers after locoregional injection of rAAV8-U7SNRNA vectors in the forelimb of GRMD dogs

National audienc