Cell Adhesion Structures in Epithelial Cells Are Formed in Dynamic and Cooperative Ways

Abstract

There are many morphologically distinct membrane structures with different functions at the surface of epithelial cells. Among these, adherens junctions (AJ) and tight junctions (TJ) are responsible for the mechanical linkage of epithelial cells and epithelial barrier function, respectively. In the process of new cell-cell adhesion formation between two epithelial cells, such as after wounding, AJ form first and then TJ form on the apical side of AJ. This process is very complicated because AJ formation triggers drastic changes in the organization of actin cytoskeleton, the activity of Rho family of small GTPases, and the lipid composition of the plasma membrane, all of which are required for subsequent TJ formation. In this review, the authors focus on the relationship between AJ and TJ as a representative example of specialization of plasma membrane regions and introduce recent findings on how AJ formation promotes the subsequent formation of TJ. Figure 6. Addition of cholesterol restores the formation of TJ in α-catenin KO cells. Time-lapse imaging of α-catenin KO epithelial cells expressing GFP-claudin-3. Cholesterol-saturated MβCD (75 mM) was added to the medium to restore the level of cholesterol in the plasma membrane at time 0. GFP-claudin-3 gradually accumulate at the cell-cell interface and TJ is formed even in the absence of AJ. Scale bar, 20 µm. Adapted with permission. [72]

A microtubule‐LUZP1 association around tight junction promotes epithelial cell apical constriction

“…Finally, this LUZP1‐based mechanism sheds new light on the importance of the association between TJs and CRs for vertebrate apical constriction. TJs are vertebrate‐specific junctions that are not only crucial for paracellular barriers with selective paracellular permeability, but also as signaling hubs regulating a variety of cellular events (Tsukita et al , 2001; Raleigh et al , 2011; Krug et al , 2014; Suzuki et al , 2014; Tamura & Tsukita, 2014; Saitoh et al , 2015; Tanaka et al , 2015, 2016; Zihni et al , 2016; Tanaka et al , 2017; Odenwald et al , 2018; Tanaka et al , 2018; Citi, 2019; Nakamura et al , 2019; Shigetomi & Ikenouchi, 2019; Tsukita et al , 2019b). Notably, in the context of TJ maturation, the association between actomyosin CRs and TJs is known to be important.…”

Permeability of the Endothelial Barrier: Identifying and Reconciling Controversies

“…Together, in vivo evidence weighs against actin stress fibers mediating endothelial cell retraction, barrier breakdown, and gap formation in postcapillary venules in vivo [102,110]. However, the cortical actin cytoskeleton is likely to contribute to the formation of finger-like processes next to gaps, maintain cell-cell contacts during gap formation, and promote gap closure, adherens junction reformation, and resolution of leakage [111].…”

Pioglitazone Attenuates Experimental Colitis-Associated Hyperalgesia through Improving the Intestinal Barrier Dysfunction

“…The above pathological changes eventually result in a profound inflammatory immune response, and in turn, worsening the damage of intestinal mucosa [10,11]. Tight junctions are composed by a series of transmembrane proteins including the claudins, occludins, junctional adhesion molecules with immunoglobulin-like domains, and intracellular scaffold proteins (i.e., zonula occludens) [12]. Tight junctions are pivotal in regulating intestinal permeability and maintaining intestinal barrier integrity.…”