Alterations of Intercellular Junctions in Peritoneal Mesothelial Cells from Patients Undergoing Dialysis: Effect of Retinoic Acid

Abstract

Tight junctions were altered in HPMCs from dialyzed patients. The HT monolayer has lower TER than LT, which might be associated with the peritoneal permeability in these patients. ATRA might be a therapeutic alternative to maintain mesothelial integrity, since it improved TJ localization and expression.

The Peritoneum: Beyond the Tissue – A Review

“…The peritoneum is generally described as a protective barrier and frictionless interphase that covers abdominal viscera ( Herrick and Mutsaers, 2004 ; Mutsaers, 2004 ; Yung et al, 2006 ; Susan and Tak Mao, 2012 ), but it is a much more complex structure with a great variety of functions. Besides from participating in the embryogenesis of primitive gut ( Burn and Hill, 2009 ), peritoneal functions include: selective fluid and cell transport ( Mutsaers, 2002 , 2004 ; Susan and Tak Mao, 2012 ; Retana et al, 2015 ; van Baal et al, 2017 ); physiological barrier ( Davies et al, 1990 ; Heel and Hall, 1996 ; Zarrinkalam et al, 2001 ; Grupp et al, 2007 ; Kazancioglu, 2009 ; Susan and Tak Mao, 2012 ); immune induction, modulation, and inhibition ( Bird et al, 2004 ; Susan and Tak Mao, 2012 ; van Baal et al, 2017 ); tissue repair and scarring ( Susan and Tak Mao, 2012 ; van Baal et al, 2017 ); preventing adhesion and tumoral dissemination ( Mutsaers, 2002 , 2004 ); and trans -cellular migration (see Figure 5 ) ( Mutsaers, 2002 ; Herrick and Mutsaers, 2004 ; Yung et al, 2006 ; Wang et al, 2010 ; van Baal et al, 2017 ).…”

“…Two mesothelial layers (visceral and parietal peritoneum) and the liquid-filled space in-between compose the peritoneal cavity ( Herrick and Mutsaers, 2004 ; Mutsaers, 2004 ; van Baal et al, 2017 ). Each mesothelium is a tortuous monolayer of overlapped mesothelial cells ( Mutsaers, 2002 , 2004 ; Retana et al, 2015 ) that rests on a basal lamina and its connective tissue underneath (sub-mesothelium) ( Michailova et al, 1999 ; Mutsaers, 2002 ; Bird et al, 2004 ; Yung et al, 2006 ; Blackburn and Stanton, 2014 ; Retana et al, 2015 ; van Baal et al, 2017 ). Sub-mesothelium varies throughout the peritoneum ( van Baal et al, 2017 ), but it invariably contains different cell types (fibroblast, adipocytes, and others), and blood and lymph vessels ( Bird et al, 2004 ).…”

“…Mesothelial cell have cellular unions like tight junctions (zonula occludens), intermediate junctions (zonula adherens), desmosomes and gap junctions ( Mutsaers, 2002 , 2004 ; Susan and Tak Mao, 2012 ; Blackburn and Stanton, 2014 ; van Baal et al, 2017 ). Tight junctions provide semipermeable properties and work as a gate regulator for water, ions, and other solutes diffusion ( Retana et al, 2015 ). Zonula adherens give structural support ( Mutsaers, 2004 ), while gap junctions are mainly aqueous intracellular channels that alongside the lymphatic stomata and intermediate pores, compose the three-pore theory ( Mutsaers, 2002 , 2004 ; Krediet et al, 2008 ; Devuyst et al, 2010 ).…”

“…These barrier functions make the peritoneum the first line of defense of the abdominal cavity ( Susan and Tak Mao, 2012 ). For example, peritoneal dialysis has been found to alter the cellular junctions of mesothelial cells ( Retana et al, 2015 ). Therefore, in peritoneal dialysis patients, the barrier functions are altered, which explains the increased risk for peritonitis ( Susan and Tak Mao, 2012 ).…”

Protective effects and mechanisms of omega‐3 polyunsaturated fatty acid on intestinal injury and macrophage polarization in peritoneal dialysis rats

“…Among these TJs, ZO‐1 (zonula occludens 1) and occludin form a ‘leak’ pathway to regulate the permeability of macromolecules and claudin forms at ‘pore’ pathway to regulate permeability of ions and small molecules . A previous study also demonstrated that the expression of TJ proteins, such as occludin and ZO‐1, was significantly decreased in human peritoneal mesothelial cells isolated from patients that received peritoneal dialysis …”