Papel do receptor aril-hidrocarboneto na atividade imunomoduladora das células-tronco mesenquimais utilizando um modelo de lesão renal aguda

• Ano de defesa: 2019
• Autor(a) principal: Evangelista, Laura Sibele Martins [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: Mesenchymal Stem Cell; Aryl-Hydrocarbon Receptor; Immunomodulation And Acute Renal Injury.; Célula-Tronco Mesenquimal; Receptor Aril-Hidrocarboneto; Imunomodulação E Lesão Renal Aguda.
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=9099905; https://repositorio.unifesp.br/handle/11600/60033

Acute kidney injury (AKI) affects millions of people worldwide with elevated mortality rate. AKI is characterized by an acute tissue inflammation with influx of inflammatory cells. The aryl-hydrocarbon receptor (AhR) is a transcription factor present in several cells and in inflammatory infiltrating cells being involved mainly in the regulation of various biological processes including the immune response. In this context, mesenchymal stem cells (MSCs) have a great immunotherapeutic potential, which can be regulated by specific receptors such as AhR. Thus, the precise mechanism associated to AhR activation in MSCs and its therapeutic role in AKI remains poorly elucidated. Therefore, in this study, we evaluated the activation of MSCs via AhR and functionally tested its therapy in an experimental model of cisplatin-induced AKI (15mg/kg, CEUA: 9656080916). Mouse adipose tissue-derived MSCs were expanded in cultures and activated with both kynurenine (KY, 50μM) or tetrachlorodibenzo-p-dioxin (TCDD, 0.2μM) agonists, which are natural and synthetic AhR inducers, respectively. At day 4 after cytotoxic injury, serum and renal tissues were collected to performing several analyzes (colorimetric, RT-PCR, flow cytometry, immunohistochemical and histopathological assays). First, we observed that MSCs were perfectly activated by AhR and expressed, in a dose-dependent manner, high levels of AhR responsive genes and its accessory molecules (CYP1b1, AhR and ARNT). In addition, these stimulated MSCs presented higher kinetics in culture (>Ki-67). Then, it was observed after both treatments with MSCs (unstimulated and KY-stimulated) similar protection in AKI-affected animals such as: lower weight loss, low creatinine and urea levels, preserved tubular renal architecture, reduced tissue apoptosis (caspase- 3) and diminished inflammation (IL-6, CCL2 and TNF-α). Moreover, we specifically analyzed in situ renal monocytes/macrophages (CD68 cells) and found lower cumulative frequency of these cells in mice treated with unstimulated MSCs. Renal macrophages (F4/80+/CD11b+) from group that received infusion of unstimulated MSCs also had an up-regulation of its immunoregulatory profile with decreased expression of M1 inflammatory markers (CCL2 and STAT3) and increased expression of M2 molecules (CD206, FIZZ1 and CX3CR1). Finally, we investigated the expression of genes associated with renal tissue metabolism and it was verified in kidneys of animals injected with unstimulated MSCs a reduced glycolytic profile (low HK2 and PK), whereas that kidneys of animals treated with KY-stimulated MSCs presented a β-oxidative pattern (high CPTA2 and ACOX1). In summary, we have documented that MSCs can be stimulated by KY via AhR and this licensing affected partially its immunoregulatory activities on renal macrophages in a model of cisplatin-induced AKI without impairing renoprotection. We believe that our findings could contribute with some insights concerning the mechanisms associated with MSCs activation and its application in several inflammatory diseases facilitating thus, its better therapeutic translation for clinical practice.