%0 Journal Article %T Polycystic Diseases in Visceral Organs %A Shakila Abdul-Majeed %A Surya M. Nauli %J Obstetrics and Gynecology International %D 2011 %I Hindawi Publishing Corporation %R 10.1155/2011/609370 %X Primary cilia are nonmotile, microtubule-based, antenna-like organelles projecting from the apical surface of most mammalian cells. Elegant studies have established the importance of ciliary structure and function in signal transduction and the sensory roles of cilia in maintaining healthy cellular state. In particular, dysfunctional cilia have been implicated in a large number of diseases mainly characterized by the presence of fluid-filled cysts in various organs. Aside from polycystic kidney disease (PKD), however, the roles of cilia in polycystic liver disease (PLD), polycystic pancreas disease (PPD), and polycystic ovarian syndrome (PCOS) are still very vague. In addition, although gender and sex hormones are known to regulate cyst formation, their roles in regulating physiological functions of cilia need to be further explored. 1. Introduction The primary cilium is an antenna-shaped organelle present on the apical surface of most mammalian cells (Figure 1). The main structural features of the primary cilium include a microtubule-based axoneme, which originates from the basal body or the mother centriole. Cilia play an important role in transmitting signals from the extracellular matrix to the cell interior, resulting in changes in gene expression and associated protein synthesis [1¨C3]. Their unique structures and locations help cells to detect and transmit even the minutest changes in the extracellular signals. Thus, cilia are important mechano- and chemosensory organelles [4, 5]. To assist in their sensory roles, cilia are bestowed with a large number of specialized proteins, known as ¡°ciliary proteins,¡± which include receptors, ion channels, and secondary messengers; many of which localize to the ciliary body or the basal body [2]. Consequently, various studies in the past have shown that improper structure and/or localization of the ciliary proteins to the cilium and/or the basal body results in a special class of diseases, collectively termed as ciliopathies [6, 7]. Figure 1: Primary cilia are present in vivo and in vitro. Primary cilia are present in all vestibular organs or tissues with vestibules (canals) that support perfusion of bodily fluid. Shown here are representative images demonstrating the presence of primary cilia in endothelial cells. (a) Scanning electron micrograph shows the presence of primary cilia in the lumen of mouse femoral artery. (b) Immunofluorescence image verify the presence of cilia in the mouse femoral endothelia. (c) When these endothelial cells were isolated, the cells retained their cilia in culture, as depicted %U http://www.hindawi.com/journals/ogi/2011/609370/