Regulation of Mesothelial Cell Fate during Development and Human Diseases

Abstract

Mesothelial cells (MCs) play a classic role in maintaining homeostasis in pleural, peritoneal, and pericardial cavities. MCs work as lubricants to reduce friction between organs, as regulators of fluid transport, and as regulators of defense mechanisms in inflammation. MCs can differentiate into various cells, exhibiting epithelial and mesenchymal characteristics. MCs have a high potential for differentiation during the embryonic period when tissue development is active, and this potential decreases through adulthood. The expression of the Wilms’ tumor suppressor gene (Wt1), one of the MC markers, decreased uniformly and significantly from the embryonic period to adulthood, suggesting that it plays a major role in the differentiation potential of MCs. Wt1 deletion from the embryonic period results in embryonic lethality in mice, and even Wt1 knockout in adulthood leads to death with rapid organ atrophy. These findings suggest that MCs expressing Wt1 have high differentiation potential and contribute to the formation and maintenance of various tissues from the embryonic period to adulthood. Because of these properties, MCs dynamically transform their characteristics in the tumor microenvironment as cancer-associated MCs. This review focuses on the relationship between the differentiation potential of MCs and Wt1, including recent reports using lineage tracing using the Cre-loxP system.

The Utility of Rectal Water Contrast Transvaginal Ultrasound for Assessment of Deep Bowel Endometriosis

“…Additionally, the presence of peritoneal fluid in the pelvic cavity presumably contributes to endometriosis development caused by retrograde menstruation [ 7 ]. Peritoneal fluid, naturally present in the abdominal cavity in small amounts, is made to lubricate the surface of tissue lining the abdominal wall and pelvic cavity and covers most of the organs at these locations [ 9 , 10 ]. Primarily, among others, produced by the developing follicles and corpus luteum, the peritoneal fluid contains electrolytes; urea; and ovarian steroidal hormones; as well as cellular components, including, for e.g., endometrial cells; macrophages; lymphocytes; and red blood cells [ 3 ].…”