Purpose To investigate whether Epac1 is key to Compound 49b's regulation of zonula occluden 1 (ZO-1) and occludin levels in human retinal endothelial cells (REC) and in an Epac1 vascular-specific conditional knockout mouse retina. Methods Primary REC were grown in normal (5 mM) or high glucose (25 mM). Some cells were treated with a novel β-adrenergic receptor agonist, Compound 49b. Additiona...

Obesity is an important risk factor for exacerbating chronic diseases such as cardiovascular disease and cancer. High serum level of saturated free fatty acids such as palmitate is an important contributor for obesity-induced diseases. Here, we examined the contribution of inflammasome activation in vascular cells to free fatty acid-induced endothelial dysfunction and vascular injury in obesity...

The oxidative-stress-induced alteration in paracellular junctional complexes was analysed in Caco-2 cell monolayer. Oxidative stress induced a rapid increase in tyrosine phosphorylation of occludin, zonula occludens (ZO)-1, E-cadherin and beta-catenin. An oxidative-stress-induced decrease in transepithelial electrical resistance was associated with a redistribution of occludin-ZO-1 and E-cadher...

Cingulin, a protein component of the submembrane plaque of tight junctions (TJ), contains globular and coiled-coil domains and interacts in vitro with several TJ and cytoskeletal proteins, including the PDZ protein ZO-1. Overexpression of Xenopus cingulin in transfected Xenopus A6 cells resulted in the disruption of endogenous ZO-1 localization, suggesting that cingulin functionally interacts w...

Enteropathogenic Escherichia coli, Shigella flexneri, and Listeria monocytogenes induce localized actin polymerization at the cytoplasmic face of the plasma membrane or within the host cytoplasm, creating unique actin-rich structures termed pedestals or actin tails. The process is known to be mediated by the actin-related protein 2 and 3 (Arp2/3) complex, which in these cases acts downstream of...

OBJECTIVE Burn-induced gut dysfunction plays an important role in the development of sepsis and multiple organ dysfunction. Emerging evidence suggests that hypoxia-inducible factor-1α (HIF-1α) is critical in paracellular barrier functions via regulating vascular endothelial growth factor (VEGF) and myosin light chain kinase (MLCK) expression. Previous studies have also demonstrated that histone...

Epithelial tight junctions regulate paracellular permeability, restrict apical/basolateral intramembrane diffusion of lipids, and have been proposed to participate in the control of epithelial cell proliferation and differentiation. Previously, we have identified ZO-1-associated nucleic acid binding proteins (ZONAB), a Y-box transcription factor whose nuclear localization and transcriptional ac...

The proper cellular location and sealing of tight junctions is assumed to depend on scaffolding properties of ZO-1, a member of the MAGUK protein family. ZO-1 contains a conserved SH3-GUK module that is separated by a variable region (unique-5), which in other MAGUKs has proven regulatory functions. To identify motifs in ZO-1 critical for its putative scaffolding functions, we focused on the SH...

Entamoeba (E.) histolytica trophozoites initiate amebiasis through invasion into the enteric mucosa. It was our aim to understand the molecular interactions between amebic trophozoites and enterocytes during the early steps of invasion. Trophozoites of E. histolytica strain HM1:IMSS were seeded on the apical side of enteric T84 cell layers, which were established on filters in two-compartment c...