Mesothelial primary cilia of peritoneal and other serosal surfaces

Abstract

The conspicuous presence of primary cilia, a small immotile cilium present on most cell types, left researchers with little doubt of their functional relevance. Recently mechanosensitive functional significance was established and a link with the pathogenesis of polycystic kidney disease. Together these discoveries have raised the profile of this, previously considered "vestigial", organelle. Primary cilia are expressed on the apical surface of serosal mesothelium and display regional variation but are more abundant on biosynthetically active cells. Adult mesothelial cells are highly biosynthetic producing a phospholipid rich surfactant that lubricates and protects the visceral organs. The mesothelium is utilized as a semipermeable membrane during peritoneal dialysis for patients with end stage renal failure. However, little is known about the functional role of primary cilia on this highly specialized cell type. The present review, examines the significance of the primary cilium in serosal mesothelial cell biology with an emphasis on ciliary location, structure, form and function. Future research is identified and discussed in view of the emerging role cilia have in other cells and the established function of the serosal mesothelium in development, normal function, peritoneal dialysis and pathology of the serosal membranes.

Functional and molecular characterization of a peritoneal dialysis model in the C57BL/6J mouse

“…The luminal side of the mesothelial cells showed numerous cytoplasmic extensions corresponding to microvilli and primary cilia. These structures are particularly developed in the visceral peritoneum, which may indicate a state of biosynthetic activation in these cells [21]. Most importantly, immunostaining confirmed the specific distribution of AQP1 and eNOS in distinct vascular beds in the PM.…”

Pathophysiology of colorectal peritoneal carcinomatosis: Role of the peritoneum

“…The luminal surface of mesothelial cells has numerous microvilli varying in shape, size and density; increasing the functional mesothelial surface area[31]. Cilia have also been identified on the surface of resting mesothelial cells[32]. The mesothelium functions as a dynamic layer that contributes substantially to the structural, functional, and homeostatic properties of the peritoneum[29].…”

Wt1 and β-catenin cooperatively regulate diaphragm development in the mouse

“…Due to this feature, both cuboidal and squamous types of mesothelial cells exist, where squamous are thought to be the most differentiated form (Herrick and Mutsaers, 2004). Cuboidal mesothelial cells coating highly mobile organs are biosynthetically active with primary cilia, abundant Golgi, rough endoplasmic reticulum, microvilli, lamellar bodies, basement membrane, cell-cell junctions, and extensive cytoskeletal networks (Bird, 2004). These cellular characteristics are important for tensile strength and flexibility.…”