Compose a 500 words essay on Disrubtion of the tight junction ZO-1 by cytokine in intestinal epithelial and probiotic treatment. Needs to be plagiarism free!d endothelial cells, in particular the inte

Compose a 500 words essay on Disrubtion of the tight junction ZO-1 by cytokine in intestinal epithelial and probiotic treatment. Needs to be plagiarism free!

d endothelial cells, in particular the intestinal epithelium and cerebral vasculature, where tight junctions have to be particularly efficient (Bazzoni and Dejana, 2004). The tight junction helps seal the spaces between cells to help form a confluent, continuous monolayer.

The role of ZO-1 in the tight junction in intestinal epithelial cells is to stabilize the barrier, functionally link it to the actin–myosin cytoskeleton, and limit the permeability of the cell layer to large solutes (Van Itallie et al, 2009). The permeability to solutes is measured in terms of trans-epithelial electrical resistance.

A variety of both exogenous and endogenous factors can affect the permeability of the intestinal epithelial tight junction. These include bacterial toxins, dietary glucose, cytokines and growth factors (Walsh et al., 2000). The role of inflammation in affecting the tight junction and increasing its permeability is clear from various studies. Piche et al. (2009) demonstrated the impairment in tight junction function and decrease in expression of ZO-1 mRNA in intestinal cells of patients with active Irritable Bowel Syndrome. however, specific cytokine mediators responsible for the effect could not be identified. Similarly, although infection with Giardia Lamblia has been found to disrupt ZO-1 integrity, the precise inflammatory cytokines responsible for the process have not been determined (Buret et al., 2002). Walsh et al. (2000) postulated in a review, based on evidence from several studies, that IFN-gamma alters paracellular permeability by several mechanisms, including possibly direct effects on the ZO-1 and/or via changes in the perijunctional actin cytoskeleton. This, however, has not been validated by studies that followed. Bruewer et al (2003) found that the cytokines IFN-gamma and TNF-alpha affected the epithelial barrier by causing internalization of transmembrane proteins, junction adhesion molecule 1, occludin, and claudin, however, their effects on