Does dexamethasone act in neuropeptides SP and CGRP in neurogenic inflammation of the skin? An experimental study

PURPOSE: To investigate the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) after subcutaneous injection of dexamethasone prior to skin incision in rats.METHODS:Twenty seven Wistar-EPM-1 rats were randomly divided into three groups. The sham group (SG) of rats was injected with 0.9 % saline. The second group (Dexa) was injected with 1.0 mg/kg dexamethasone, and the third group (Dexa+) was injected with 10.0 mg/kg dexamethasone. In all groups, the three subcutaneous injections were performed 30 minutes prior to the surgical skin incision and tissue collection. SP and CGRP (15 kDa pro-CGRP and 5 kDa CGRP) were quantified by Western Blotting.RESULTS: No statistically significant differences (p>0.05) were found in pro-CGRP, CGRP and SP values in all three groups.CONCLUSION:The anti-inflammatory effect of dexamethasone did not occur when the substance P and calcitonin gene-related peptide levels were altered during the neurogenic inflammation process of skin wound healing in rats.

Effects of subcutaneous carbon dioxide on calcitonin gene related peptide and substance P secretion in rat skin

To investigate the subcutaneous injection of carbon dioxide (CO2) on neuropeptides Calcitonin Gene-Related Peptide (CGRP) and Substance P (SP) secretion in rat skin. Fifty-six Wistar-EPM rats were distributed in two groups: one for CGRP analysis, the other for SP analysis. Each group was subdivided into four subgroups: control (Cont), control with needle (ContNd), CO2 injection (CO2Inj) and atmospheric air injection (AirInj) - with seven animals each. Sample analyses of partial skin were conducted by Western Blotting (WB). RESULTS: In SP group, there was a decrease in the amount of neuropeptides in subgroups CO2Inj and AirInj. Similarly, in CGRP group, there was a decrease in the amount of pro-CGRP neuropeptides (15 kDa) in subgroups CO2Inj and AirInj; Nevertheless, there was no decrease in the amount of CGRP (5 kDa) in any subgroups. Subcutaneous injection of CO2 and atmospheric air decreased the amount of Substance P and pro-Calcitonin Gene-Related Peptide (15 kDa) neuropeptides in rat skin.

The review of the methods to obtain non-neuronal cells to study glial influence on Amyotrophic Lateral Sclerosis pathophysiology at molecular level in vitro / Revisão dos métodos de obtenção de células não neuronais para o estudo da fisiopatologia da Esclerose Lateral Amiotrófica ao nível molecular in vitro

PURPOSE: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that displays a rapid evolution. Current treatments have failed to revert clinical symptoms because the mechanisms involved in the death of motoneuron are still unknown. Recent publications have put non-neuronal cells, particularly, astrocyte and microglia, in the scenario of pathophisiology of the disease. Animal models for ALS, particularly transgenic mice expressing the human SOD1 gene with a G93A mutation (hSOD1), are available and display the phenotype of the disease at cellular and clinical levels. However, it is a lack of detailed information regarding the methods to study the disease in vitro to better understand the contribution of non-neuronal cells in the onset and progression of the pathology. METHODS: Colonies of Swiss mice and transgenic mice expressing hSOD1 mutation as well as non-transgenic controls (wild-type) were amplified after a genotyping evaluation. Disease progression was followed behaviorally and mortality was registered. Highly purified primary cultures of astrocytes and microglia from mouse spinal cord were obtained. Cells were identified by means of GFAP and CD11B immunocytochemistry. The purity of astroglial and microglial cell cultures was also accompanied by means of Western blot and RT-PCR analyses employing a number of markers. RESULTS: The disease onset was about 105 days and the majority of transgenic mice displayed the disease symptoms by 125 days of age and reached the endpoint 20 days later. A substantial motor weakens was registered in the transgenic mice compared to wild-type at the end point. Immunocytochemical, biochemical and RT-PCR analyses demonstrated a highly purified primary cultures of spinal cord astrocytes and microglia. CONCLUSION: It is possible to achieve highly purified primary cultures of spinal cord astrocytes and microglia to be employed in cellular and molecular analyses of the influence of such non-neuronal cells in the pathophysiology of ALS.

OBJETIVO: A esclerose lateral amiotrófica (ELA) é uma doença neurodegenerativa fatal com evolução rápida. Os tratamentos atualmente disponíveis falham em reverter os sintomas porque os mecanismos envolvidos na morte do neurônio motor ainda não são conhecidos. Publicações recentes colocam as células não neuronais, particularmente o astrócito e a microglia, no cenário da fisiopatologia da doença. Modelos animais para a ELA, particularmente os camundongos transgênicos que expressam o gene da SOD1 humana (hSOD1) mutante estão disponíveis e mostram o fenótipo da doença ao nível celular e clínico. Entretanto, informações detalhadas são escassas sobre os métodos de estudo da doença in vitro para a melhor compreensão da participação das células não neuronais no início e na progressão da patologia. MÉTODOS: Colônias de camundongos Swiss e camundongos transgênicos que expressam a hSOD1 mutante assim como os controles não transgênicos (selvagem) foram amplificadas após avaliação genotípica. A progressão da doença foi acompanhada pelo comportamento e a mortalidade foi registrada. Culturas primárias altamente purificadas de astrócitos e microglia da medula espinal dos camundongos foram obtidas. As células foram identificadas pela immunocitoquímica da GFAP e CD11B. A pureza das culturas de astrócitos e microglia foi acompanhada pelas análises do Western blot e RT-PCR empregando-se marcadores específicos. RESULTADOS: Os primeiros sinais da doença ocorreram por volta dos 105 dias de vida e a maioria dos camundongos transgênicos já estava com a doença manifestada aos 125 dias de idade e alcançaram o estágio terminal aproximadamente 20 dias depois. Fraqueza substancial da força muscular foi registrada nos animais transgênicos comparados com os animais selvagens. Análises imuncitoquímica, bioquímica e pelo RT-PCR demonstraram culturas primárias altamente purificadas de astrócito e microglia da medula espinal dos camundongos. CONCLUSÃO: É possível obter culturas purificadas de astrócitos e microglia da medula espinal do camundongo a ser empregadas em análises celulares e moleculares da influência destas células não neuronais na fisiopatologia da ELA.