The Role of Peritoneal Macrophages in Endometriosis

Abstract

Endometriosis is an estrogen-dependent gynecological disorder, defined as the growth of endometrial stromal cells and glands at extrauterine sites. Endometriotic lesions are more frequently located into the abdominal cavity, although they can also be implanted in distant places. Among its etiological factors, the presence of immune dysregulation occupies a prominent place, pointing out the beneficial and harmful outcomes of macrophages in the pathogenesis of this disease. Macrophages are tissue-resident cells that connect innate and adaptive immunity, playing a key role in maintaining local homeostasis in healthy conditions and being critical in the development and sustainment of many inflammatory diseases. Macrophages accumulate in the peritoneal cavity of women with endometriosis, but their ability to clear migrated endometrial fragments seems to be inefficient. Hence, the characteristics of the peritoneal immune system in endometriosis must be further studied to facilitate the search for new diagnostic and therapeutic tools. In this review, we summarize recent relevant advances obtained in both mouse, as the main animal model used to study endometriosis, and human, focusing on peritoneal macrophages obtained from endometriotic patients and healthy donors, under the perspective of its future clinical translation to the role that these cells play on this pathology.

Huayu Sanjie Enema Liquid Relieves Pain in Endometriosis Model Rats by Inhibiting Inflammation, Peripheral Sensitization, and Pelvic Adhesion

“…Recent studies have found that the inflammatory response, peripheral nerve sensitization, and pelvic adhesion are involved in the generation of pelvic pain in EMs. They interact with each other, directly or indirectly to stimulate nerve endings or mediate the sensitivity of nerve endings, thus inducing pain [ 23 , 24 ].…”

Evaluating the Phagocytic Index of Peripheral Leukocytes in Endometriosis by Plasma Experiments

“…Macrophages, deriving from monocytes, and neutrophil granulocytes, play a significant role in the development of inflammation and the immune response in the peritoneal environment; therefore, examining these cells from peripheral blood seems to be important [ 26 , 27 ]. It was also demonstrated that macrophages produce a significantly increased amount of proinflammatory cytokines, and there are data about defects in the phagocyte function [ 28 , 29 ]. Macrophages, natural killer cells and dendritic cells are present in peritoneal fluid with altered immunological function, which may be responsible for the residues of invaded menstrual debris [ 30 ].…”

Peritoneal autoantibody landscape in endometriosis

“…B-cells, T-cells, and macrophages are key immune cells in the maintenance of immune tolerance, and conversely, their dysfunction in autoimmunity. Macrophages are important immune cells that maintain immune homeostasis via phagocytosis of foreign matter, apoptotic or necrotic cells and are recruited to the peritoneum and prominently associated with endometriosis [22][23][24] . Macrophages play a central role in the homeostatic clearance of cell corpses and debris by presenting antigens to T and B cells and secreting cytokines that direct the responses of T and B cells.…”

“…Intrinsic defects in peritoneal macrophages in endometriosis may also contribute to autoimmunity. Macrophages are important immune cells that maintain immune homeostasis via phagocytosis of foreign matter, apoptotic or necrotic cells, and are recruited to the peritoneum where they are prominently associated with endometriosis [22][23][24] . Dysregulation in these immune cells promotes skewed tolerogenic peritoneal environments in endometriosis.…”