Polarização de macrófagos na hipertensão arterial

• Ano de defesa: 2019
• Autor(a) principal: Cavalcante, Paula Andrea Malveira [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Nefropatias; Macrófagos; Hipertensão
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=9097006; https://repositorio.unifesp.br/handle/11600/60036

Macrophage-mediated events contribute to a continuous increase in blood pressure and kidney injury in hypertension. There are indications that the relationship between the macrophagic phenotypes M1 and M2 is the component responsible for the development and maintenance of hypertension. However, the imbalance between the phenotypes and underlying mechanisms has not yet been clarified. Additionally, it is still unknown if the YM1/Chi3l3 marker has functions in hypertension and hypertensive nephropathy. YM1/Chi3l3 is a chitinase-3-like protein, expressed by M2 macrophages in different mouse tissues and is associated with functional recovery and restoration. The experiments were done with 2 animal models. MODEL 1. 10- to 12-week-old male mice C57BL/ 6 were divided into two groups, normotensive (C) (n = 6) and hypertensive (H) (n = 6) controls. Experimental groups received either saline or Ang II. The infusion was done through osmotic minipumps for 25 days. Systolic blood pressure was measured by plethysmography. The expression of genes related to the polarization of macrophages M1 and M2 were evaluated in the kidneys by real-time PCR. MODEL 2. Transgenic mice expressing the form of rat angiotensinogen (TGM (rAOGEN) 123, TGM123-FVB / N), hypertensive,10- to 12-week-old male (n = 9) and normotensive controls (FVB / N) (n = 9). Bone marrow cells were isolated from the femurs and tibia of the animals. To promote polarization in the M1 and M2 phenotypes, the cells were treated with LPS + IFN-γ and IL-4 + IL-13, respectively. Kidneys of TGM123-FVB/N animals were also examined. Real-time PCR was used to analyze gene expression as well as ELISA, western blot, CBA and immunofluorescence, and histology to assess protein levels. MODEL 1. After the twenty-five days of infusion with Ang II, an increase in BP was found, however, we did not find significant changes in the kidneys of hypertensive animals. MODEL 2. The groups (control and hypertensive) stimulated with LPS+IFN-γ in vitro showed no significant difference in the expression of CD86, an M1 marker gene, compared to cells from the controls. When stimulated with IL4+IL13, however, macrophages of the hypertensive group showed a significant increase in CD206 expression, an M2 marker gene, compared to the control group, and the M2/M1 ratio reached 288%. In the kidneys, the histology confirmed high levels of renal collagen. We found infiltration of predominantly polarized macrophages into the M2 phenotype associated with elevated levels of YM1/Chi3l3 (91.89%). MODEL 1. Despite confirmation of the hypertensive state, the twenty-five days of increase in blood pressure were not enough to induce alterations in the polarization of macrophages in the kidneys of the animals. MODEL 2. This study unveiled an important role of M2 macrophages and the YM1/Chi3l3 in hypertensive nephropathy. Our results indicate that, when stimulated in vitro, the macrophages of transgenic hypertensive mice are predisposed toward polarization to an M2 phenotype. These data support the results in the kidneys where we found an increased infiltration of predominantly polarized to M2 associated with high levels of YM1/Chi3l3 (91,89%), suggesting that YM1/Chi3l3 may be a biomarker of hypertensive nephropathy.