O papel do inflamassoma NLRP3 e caspase 1/11 na modulação da adipogênese, inflamação e microbiota

Tese (doutorado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Patologia Molecular, 2017.A obesidade é uma doença reconhecida pela Organização Mundial da Saúde (OMS) desde 1997. Devido a vários fatores (genéticos, ambientais, dietéticos), esta doença atualmente é uma grande parte da população mundial e está associada a várias outras patogenicidades. Vários estudos mostraram que quantidades maiores de gordura corporal estão associadas a riscos aumentados de vários tipos de câncer. A inflamação está relacionada à obesidade e ao câncer. Os mediadores pró-inflamatórios causam efeitos locais e sistêmicos. O inflamassoma NLRP3, um importante complexo proteico para o processo inflamatório, é responsável pela maturação das citocinas pró-inflamatórias IL-1β e IL-18. A ausência de componentes da inflamação já foi relacionada a um aumento de peso aumentado. Outro fator intimamente relacionado com obesidade, inflamação e, consequentemente, câncer é a microbiota. A filogenia e os metabólitos da microbiota intestinal podem desempenhar um papel benéfico e protetor ou nocivo, sendo relacionados ao desenvolvimento de doenças no hospedeiro. Ainda, existem dois tipos de adipócitos presentes no corpo – branco (WAT), amplamente distribuído e mais conhecido por seu papel no armazenamento de gordura, e marrom (BAT), localizados em depósitos específicos e com papel termogênico – têm papéis distintos na modulação do metabolismo e da resposta imune. O presente estudo avaliou o papel do inflamassoma NLRP3 no perfil inflamatório, metabolismo lipídico e na modulação da microbiota intestinal de animais obesos. Também foi avaliado se a abundância de WAT e BAT é modificada com a depleção dos componentes do inflamassoma e a ativação de macrófagos induzida por esses tecidos e o papel do inflamassoma nessa ativação. Para a primeira parte, camundongos selvagens e deficientes para caspase 1/11 e NLRP3 do inflamassoma foram alimentados com dieta convencional e rica em lipídeos (45% de calorias advindas de lipídeos) por 90 dias, a resposta inflamatória, o metabolismo de lipídeos e a filogenia da microbiota intestinal foram analisados. Nossos dados sugerem que animais nocautes para caspase1/11 apresentaram maior suscetibilidade à obesidade, com consequentes alterações dos marcadores de metabolismo lipídico e inflamatórios (esteatose hepática, biogênese de corpúsculos lipídicos, secreção de IL-12 e CD1d em células do lavado peritoneal), mudanças metabolômicas no perfil lipídico global do fígado e alteração na abundância filogenética da microbiota intestinal, apresentando filos envolvidos com ganho de peso e esteatose hepática; indicando uma modulação imunológica e no metabolismo lipídico. Na segunda parte, WAT e BAT foram retirados de animais selvagens e depletados para componentes de inflamassoma, mantidos em meio de cultura e o sobrenadante foi usado para estimular macrófagos de medula óssea (BMDM). Os animais nocautes apresentaram uma distribuição distinta desses tecidos e o uso do sobrenadante WAT e BAT depletados para proteínas do inflamassoma NLRP3 sugere que este complexo desempenha um papel importante na ativação de macrófagos regulada pelo tecido adiposo. Tomados em conjunto, nossos resultados sugerem que a ausência de caspase 1/11 modulam a abundância de WAT e BAT, que possuem papéis diferenciados na ativação de células imunes e, ainda, que a obesidade induzida pela dieta rica em gordura e a ausência de caspase 1/11 podem regular o metabolismo lipídico, a resposta inflamatória e a composição da microbiota intestinal.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).Obesity is a disease recognized by the World Health Organization (WHO) since 1997. Due to several factors (genetic, environmental, dietary), this disease is currently a large part of the world population and is associated with several other pathogenicities. Several studies have shown that higher amounts of body fat are associated with increased risks of various types of cancer. Inflammation is related to obesity and cancer. Pro-inflammatory mediators cause local and systemic effects. The inflammasome NLRP3, an important protein complex for the inflammatory process, is responsible for the maturation of the proinflammatory cytokines IL- 1βand IL-18. The absence of components of the inflammasome has already been related to an increased weight gain. Another factor closely related to obesity, inflammation and, consequently, cancer is the microbiota. The phylogeny and metabolites of the gut microbiota may play a beneficial and protective or deleterious role, being related to the development of diseases in the host. Furthermore, there are two types of adipocytes present in the body - white (WAT), widely distributed and better known for their role in fat storage, and brown (BAT), located in specific deposits and with thermogenic paper - have distinct roles in modulating metabolism and immune response. The present study evaluated the role of NLRP3 inflammation in the inflammatory profile, lipid metabolism and modulation of the intestinal microbiota of obese animals. It was also evaluated whether the abundance of WAT and BAT is modified by the depletion of the components of the inflammasome and the activation of macrophages induced by these tissues and the role of the inflammasome in this activation. For the first part, wild-type and caspase-deficient mice 1/11 and NLRP3 of the inflammasome were fed with a conventional diet and rich in lipids (45% of calories from lipids) for 90 days, the inflammatory response, lipid metabolism and phylogeny of the intestinal microbiota were analyzed. Our data suggest that animal knockouts for caspase 1/11 were more susceptible to obesity, with consequent changes in the markers of lipid and inflammatory metabolism (hepatic steatosis, biogenesis of lipid bodies, IL-12 and CD1d secretion in peritoneal lavage cells), changes metabolomics in the global lipid profile of the liver and alteration in the phylogenetic abundance of the intestinal microbiota, presenting phyla involved with weight gain and hepatic steatosis; indicating immunological modulation and lipid metabolism. In the second part, WAT and BAT were taken from wild animals and depleted for inflammasome components, kept in culture medium and the supernatant was used to stimulate bone marrow derived macrophages (BMDM). The knockout animals showed a distinct distribution of these tissues and the use of the supernatant WAT and BAT depleted for proteins of the NLRP3 inflammasome suggests that this complex plays an important role in the activation of macrophages regulated by adipose tissue. Taken together, our results suggest that the absence of caspase 1/11 modulate the abundance of WAT and BAT, which have differentiated roles in the activation of immune cells and also that obesity induced by the high fat diet and the absence of caspase 1/11 can regulate lipid metabolism, inflammatory response and intestinal microbiota composition

Adipocytes and macrophages interplay in the orchestration of tumor microenvironment : new implications in cancer progression

Inflammation has been known as one of the main keys to the establishment and progression of cancers. Chronic low-grade inflammation is also a strategic condition that underlies the causes and development of metabolic syndrome and obesity. Moreover, obesity has been largely related to poor prognosis of tumors by modulating tumor microenvironment with secretion of several inflammatory mediators by tumor-associated adipocytes (TAAs), which can modulate and recruit tumor-associated macrophages. Thus, the understanding of cellular and molecular mechanisms that underlay and link inflammation, obesity, and cancer is crucial to identify potential targets that interfere with this important route. Knowledge about the exact role of each component of the tumor microenvironment is not yet fully understood, but the new insights in literature highlight the essential role of adipocytes and macrophages interplay as key factor to determine the fate of cancer progression. In this review article, we focus on the functions of adipocytes and macrophages orchestrating cellular and molecular mechanisms that lead to inflammatory modulation in tumor microenvironment, which will be crucial to cancer establishment. We also emphasized the mechanisms by which the tumor promotes itself by recruiting and polarizing macrophages, discussing the role of adipocytes in this process. In addition, we discuss here the newest possible anticancer therapeutic treatments aiming to retard the development of the tumor based on what is known about cancer, adipocyte, and macrophage polarization

Adipocytes and Macrophages Interplay in the Orchestration of Tumor Microenvironment: New Implications in Cancer Progression

Inflammation has been known as one of the main keys to the establishment and progression of cancers. Chronic low-grade inflammation is also a strategic condition that underlies the causes and development of metabolic syndrome and obesity. Moreover, obesity has been largely related to poor prognosis of tumors by modulating tumor microenvironment with secretion of several inflammatory mediators by tumor-associated adipocytes (TAAs), which can modulate and recruit tumor-associated macrophages. Thus, the understanding of cellular and molecular mechanisms that underlay and link inflammation, obesity, and cancer is crucial to identify potential targets that interfere with this important route. Knowledge about the exact role of each component of the tumor microenvironment is not yet fully understood, but the new insights in literature highlight the essential role of adipocytes and macrophages interplay as key factor to determine the fate of cancer progression. In this review article, we focus on the functions of adipocytes and macrophages orchestrating cellular and molecular mechanisms that lead to inflammatory modulation in tumor microenvironment, which will be crucial to cancer establishment. We also emphasized the mechanisms by which the tumor promotes itself by recruiting and polarizing macrophages, discussing the role of adipocytes in this process. In addition, we discuss here the newest possible anticancer therapeutic treatments aiming to retard the development of the tumor based on what is known about cancer, adipocyte, and macrophage polarization