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Effects of hyperbaric oxygen on the tight junction of intestinal epithelial cells Caco-2 in ischemia-reperfusion injury

Objective 
To investigate the effects of hyperbaric oxygen (HBO) on the tight junction (TJ) of monolayer human intestinal epithelial cells Caco-2 in ischemia reperfusion (I/R) injury in vitro. 
 
 
Methods 
In the culture of human intestinal monolayer epithelial cells Caco-2, 0.5 mmol/L t-buooh was used to induce I/R injury of intestinal epithelial cells in vitro. The monolayer Caco-2 cells were randomly divided into 5 groups (n=8 cases): the control group, the ischemia/ reperfusion group (I/R), the hyperbaric oxygen preconditioning group (HBO-P), the HBO intervention during ischemia group (HBO-I) and the HBO intervention during reperfusion group (HBO-R). Transmembrane electrical impedance detection (TEER) was used to detect the opening of the tight junction between epithelial cells of the intestinal mucosa and evaluate its permeability. The transcription of tight ligandin ZO-1 between cells was detected by RT-PCR. 
 
 
Results 
Results indicated that the impedance as shown by TEER was in the following order: the impedance value of the control group was the highest, then came the HBO-P group, further down was the HBO-R group, and at the end was the HBO-I group. Statistical significance could be noted when comparisons were made between the HBO-P group and all the other groups(P 0.05). 
 
 
Conclusions 
HBO intervention seemed to have a certain protective effect on the tight junction of monolayer Caco-2 cells, and inhibit the decrease of tight ligandin ZO-1, the mechanism of which might be associated with the maintenance of the level of ZO-1. HBO intervention before ischemia and during reperfusion seemed to have beneficial effects, and HBO preconditioning could produce better results. Nevertheless, HBO intervention during ischemia seemed to be ineffective. 
 
 
Key words: 
Hyperbaric oxygen; Ischemia-reperfusion injury; Tight junction; Monolayer intestinal cancer cell (Caco-2); ZO-1