Avaliação do efeito reparativo e regenerativo da lL-4 no músculo isquêmico através da expansão de macrófagos residentes com fenótipo M2

• Ano de defesa: 2018
• Autor(a) principal: Honda, Tâmisa Seeko Bandeira [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: M2 macrophage; Resident macrophage,; Peripheral arterial disease,; Member ischemia; Macrófagos M2; Macrófagos residentes; Doença arterial periférica; Isquemia de membro
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=6575875; https://repositorio.unifesp.br/handle/11600/53061

Introduction: Peripheral arterial disease is caused by obstruction of the arteries of the lower limbs, mainly due to atherosclerosis. The inflammation inherent to atherosclerosis and hypoperfusion has at its core a monocytic / macrophagic infiltrate, which is also involved in the healing process and vascular remodeling. IL-4 is an antiinflammatory cytokine capable of polarizing macrophages into an M2 phenotype, evolved with tissue repair. Aim: To determine if the administration of IL-4 after ischemia is capable of expanding M2 macrophages and thus contribute to the recovery of ischemic muscle. Methods: Limb ischemia was induced in 10-12 week male Balb / c mice by electrocautery of the femoral artery. Three days after ischemia, 50 μg of the uP-IL-4 vector were electroporated into the rectus femoris muscle. Blood and muscle were collected on days 2, 4, 7 and 14 for analysis of IL-4 expression by ELISA and macrophage monocyte subpopulations by flow cytometry. Weekly, we measured the blood flow by Laser Doppler and the degree of necrosis of the limb by visual score. At the end of the 30 days, the muscle strength of the gastrocnemius muscle was measured and the muscles were removed for histology. The procedures were approved by CEUA 2941120716. Results: Animals treated with the uP-IL4 vector had higher (p <0.01) levels of expression of this cytokine on day two after treatment. High IL-4 expression may have contributed to a lower degree of nail necrosis and a 60% recovery of muscle contractility capacity (p <0.05) when compared to ischemic animals. Morphologically, the uP-IL4 treated muscle had lower amounts of regenerating fibers (p <0.05) and intramuscular adipose tissue (p <0.001). However, no significant change in collagen deposition was observed. Concerning monocyte subpopulations, it was observed that administration of uP-IL4 significantly elevated (p <0.01) the Ly6ChiCX3CR1low monocytes on day 2 after treatment. This increase was accompanied by a reduction (p <0.01) of the Ly6ClowCX3CR1hi monocytes. MHC + CD206-macrophage apparently had no effects resulting from uP-IL4 treatment. However, MHC-CD206 + macrophages were elevated on day 2. Conclusion: Treatment with uP-IL4 expanded and made precocious tissue macrophages with M2 phenotype and this increase improved muscle strength and ischemic muscle visual necrosis scores.