Review article: Is obesity an inflammatory illness? Role of low-grade inflammation and macrophage infiltration in human white adipose tissue

Authors

  • R Cancello,

    Corresponding author
    1. Institut National de la Santé et de la Recherche Médicale (INSERM) U755 Nutriomique, Paris, France; Faculty of Medicine Les Cordeliers, Pierre and Marie Curie-Paris 6 University, Paris, France; Nutrition Department, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôtel-Dieu Hospital, Paris, France
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  • K Clément

    1. Institut National de la Santé et de la Recherche Médicale (INSERM) U755 Nutriomique, Paris, France; Faculty of Medicine Les Cordeliers, Pierre and Marie Curie-Paris 6 University, Paris, France; Nutrition Department, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôtel-Dieu Hospital, Paris, France
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Dr R Cancello, Institut National de la Santé et de la Recherche Médicale (INSERM) U755 ‘Nutriomique’, UMPC, Paris 6, Service of Nutrition, Hôtel-Dieu, 1 place du parvis Notre Dame, 75004 Paris, France. Email raffaella.cancello@ea3502.org

Abstract

There are at least two scientific evidences of human obesity as a chronic inflammatory illness: first, the well-described moderate increase of inflammatory factors in the circulation in obese subjects, and second, the recent identification of macrophage cells infiltrating the white adipose tissue (WAT). These observations led to a revision of the physiopathology of obesity and its co-morbidities. It has been suggested that the ‘low-grade’ inflammatory state associates with metabolic and cardiovascular complications of obesity. Weight loss is able to improve this inflammatory state by both significantly decreasing circulating inflammatory molecules and macrophage cell infiltration in WAT depots. However, the mechanisms of WAT macrophage recruitment into the adipose tissue and their role in obesity complications have not been defined. This review aims to point out the knowledge on inflammatory cytokines associated with obesity and focuses on macrophage infiltration in human WAT, discussing their recruitment and role. The interactions of macrophages with adipocytes will certainly be the subject of intense investigations in the future.

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