Protective Effects of Baicalin on Peritoneal Tight Junctions in Piglets Challenged with Glaesserella parasuis

Abstract

Glaesserella parasuis (G. parasuis) causes inflammation and damage to piglets. Whether polyserositis caused by G. parasuis is due to tight junctions damage and the protective effect of baicalin on it have not been examined. Therefore, this study aims to investigate the effects of baicalin on peritoneal tight junctions of piglets challenged with G. parasuis and its underlying molecular mechanisms. Piglets were challenged with G. parasuis and treated with or without baicalin. RT-PCR was performed to examine the expression of peritoneal tight junctions genes. Immunofluorescence was carried out to detect the distribution patterns of tight junctions proteins. Western blot assays were carried out to determine the involved signaling pathways. Our data showed that G. parasuis infection can down-regulate the tight junctions expression and disrupt the distribution of tight junctions proteins. Baicalin can alleviate the down-regulation of tight junctions mRNA in peritoneum, prevent the abnormalities and maintain the continuous organization of tight junctions. Our results provide novel evidence to support that baicalin has the capacity to protect peritoneal tight junctions from G. parasuis-induced inflammation. The protective mechanisms of baicalin could be associated with inhibition of the activation of PKC and MLCK/MLC signaling pathway. Taken together, these data demonstrated that baicalin is a promising natural agent for the prevention and treatment of G. parasuis infection.

Baicalin Protects Vascular Tight Junctions in Piglets During Glaesserella parasuis Infection

“…Baicalin can alleviate the phosphorylation of PKC-α and PKCδ, which is in consistent with our previous work and the results of other studies of the regulation effects of baicalin on PKC (26,40,(51)(52)(53). The results suggest that the protective effect of baicalin on vascular TJ may be related to inhibit PKC or the downstream pathways.…”

“…Evidence showed that G. parasuis demonstrated extreme adhesion and invasion properties to porcine aorta endothelial cells and brain microvascular endothelial cells (39), suggesting that G. parasuis could damage the vascular barrier. Necropsy results in our previous experiment show that G. parasuis caused server pericarditis, peritonitis, meningitis, and septicemia in piglets (27,40). EP and FM were used as positive controls in the experiment derived from their anti-inflammatory effects to control inflammation-related diseases (27).…”

Baicalin alleviates endometrial inflammatory injury through regulation of tight junction proteins

“…25 Baicalin exhibits ameliorative effects on barrier damage in the brain, peritoneum, and vessels. 26–28 Here, we found that baicalin prevented endometrial barrier integrity by altering the redistribution of TJ proteins via autophagy. Pharmacological and genetic modification of autophagy affects the baicalin-induced redistribution of TJ proteins with LPS treatment (Fig.…”

Carvacrol attenuated lipopolysaccharide-induced intestinal injury by down-regulating TLRs gene expression and regulating the gut microbiota in rabbit

“…During this process, some genes occur protein loss and mislocalization, which suggests that TNF-α can disrupt TJs, thereby negatively affecting intestinal barrier function 47 . Studies have reported that ZO-1 mislocalization disrupts the stability of TJ complexes in both rats and piglets 48 , 49 . In the present study, adding CAR to the diet alleviated the marked increase in TNF-α expression and the significant reduction in ZO-1 , occludin , and claudin 1 genes expression in the rabbit intestine after LPS stimulation.…”