Neuronal over-expression of chromogranin A accelerates disease onset in a mouse model of ALS
JOURNAL OF NEUROCHEMISTRY
Authors: Abou Ezzi, Samer; Lariviere, Roxanne; Urushitani, Makoto; Julien, Jean-Pierre
Abstract
Recent studies provided evidence that chromogranins can interact with mutant superoxide dismutase 1 (SOD1) and that chromogranin B (CgB) may act as a susceptibility gene and modifier of onset in amyotrophic lateral sclerosis (ALS). To further investigate the role of chromogranins in ALS pathogenesis, we generated SOD1(G37R) mice that over-express CgA under the control of Thy1 promoter. Here, we report that neuronal over-expression of CgA in SOD1(G37R) mice caused acceleration of onset of motor impairment and exacerbation of motor neuron degeneration. The use of monoclonal antibody specific to misfolded mutant SOD1 demonstrated a higher level of misfolded SOD1 species in double transgenic mice compared to SOD1(G37R) mice, suggesting a stabilization of pathogenic SOD1 species by excess CgA. These results suggest a role of chromogranins as modulators of disease onset in ALS pathogenesis.
Biocompatible Gels of Chitosan-Buriti Oil for Potential Wound Healing Applications
MATERIALS
Authors: Goncalves Ferreira, Maria Onaira; Lima, Idglan Sa; Ribeiro, Alessandra Braga; Lobo, Anderson O.; Rizzo, Marcia S.; Osajima, Josy Anteveli; Estevinho, Leticia Miranda; Silva-Filho, Edson C.
Abstract
The buriti oil (Mauritia flexuosa L.) can be associated with polymeric matrices for biomedical applications. This study aimed to evaluate the effect of chitosan gel (CG) associated with buriti oil (CGB) as a healing agent. The fatty acids and volatile compounds composition of buriti oil were performed and the composite gels were characterized using FTIR and thermal analysis. Biological tests including antimicrobial, antioxidant, anti-inflammatory and healing effects were also investigated. Buriti oil is composed of oleic and palmitic acids, and the main volatile compounds were identified. The buriti oil did not show antimicrobial activity, on the other hand, the composite gel (chitosan and oil) proved to be efficient against Staphylococcus aureus and Klebsiella pneumonia at the 10 mg/mL. Similar behavior was observed for antioxidant activity, determined by the beta-carotene bleaching assay, composite gels presenting higher activity and buriti oil showed anti-inflammatory activity, which may be related to the inhibition of the release of free radicals. Regarding wound healing performed using in vivo testing, the composite gel (CGB) was found to promote faster and complete wound retraction. The results indicated that the gel chitosan-buriti oil has a set of properties that improve its antibacterial, antioxidant and healing action, suggesting that this material can be used to treat skin lesions.