Expression of Mucins and Claudins in the Colon during Acute and Chronic Experimental Colitis

The Possible Anti-Inflammatory Effect of Dehydrocostus Lactone on DSS-Induced Colitis in Mice

BACKGROUND

Dehydrocostus lactone (DL), one of the main active constituents in Aucklandia lappa Decne. (Muxiang), reported to have anti-inflammatory, antiulcer, and immunomodulatory properties. However, the effect of DL on ulcerative colitis (UC) has not been reported. To analyze the anti-inflammatory potential role of DL in UC, we provide a mechanism for the pharmacological action of DL.

METHODS

The experimental model of UC was induced by using oral administration of 2% dextran sulfate sodium (DSS) with drinking water in BALB/c mice. Mesalazine (Mes, 0.52 g/kg/d), DL-high doses (DL-H, 20 mg/kg/d), DL-middle doses (DL-M, 15 mg/kg/d), DL-low doses (DL-L, 10 mg/kg/d) were gavaged once a day from day 4 to day 17. Disease activity index (DAI) was calculated daily. On day 18, mice were rapidly dissected and the colorectal tissues were used to detect the levels of UC-related inflammatory cytokines (TNF-α, IL-1β, MCP-1, MPO, SOD, IL-6, IL-17, and IL-23), IL-6/STAT3 inflammatory signaling pathway (iNOS, COX2, IL-6, GP130, L-17, and IL-23), and colorectal mucosal barrier-related regulatory factors (MUC2, XBP1s, and α, IL-1.

RESULTS

DL reduced the colorectal inflammation histological assessment, decreased UC-related inflammatory cytokines (TNF-α, IL-1β, MCP-1, MPO, SOD, IL-6, IL-17, and IL-23), IL-6/STAT3 inflammatory signaling pathway (iNOS, COX2, IL-6, GP130, L-17, and IL-23), and colorectal mucosal barrier-related regulatory factors (MUC2, XBP1s, and α, IL-1.

CONCLUSIONS

DL possessed the potential of anti-inflammatory effect to treated colitis. The protective mechanism of DL may involve in reducing inflammation and improving colorectal barrier function via downregulating the IL-6/STAT3 signaling.

The Characteristics of Intestinal-Barrier Damage in Rats With IgA Nephropathy

BACKGROUND

Intestinal-barrier damage plays an important pathogenic role in immunoglobulin A nephropathy (IgAN). In this study, we explored the characteristics of the intestinal barrier in rats with IgAN.

MATERIALS AND METHODS

We randomly divided 17 Sprague Dawley (SD) male rats into a normal control group (NC; n = 9) and an IgAN model group (n = 8). Feces in the distal ileum were taken for intestinal-microbiota 16sDNA sequencing. We also took a segment of terminal ileum to analyze intestinal morphology and to detect mRNA and protein expression of the tight-junction proteins zonula occludens-1 (ZO-1) and occludin (OCLN), as well as of mucin 2 (MUC2). We then measured levels of serum diamine oxidase (DAO) and D-lactic acid (D-LA), the biomarkers of intestinal permeability.

RESULTS

Compared with the NC group, mRNA expression levels of ZO-1 (t = 4.216, P = 0.0007), OCLN (t = 2.413, P = 0.029) and MUC2 (t = 0.859, P < 0.0001) were significantly decreased in the IgAN model group. Protein expression of ZO-1 (t = 7.349, P < 0.0001) and OCLN (t = 6.367, P < 0.0001) was also decreased in the IgAN model group. Conversely, serum DAO (t = 3.758, P = 0.0024) and D-LA (t = 2.246, P = 0.0427) levels increased in this group. At the genus level, the relative abundance of Ruminococcus2 (P = 0.0086) was increased in the IgAN model group.

CONCLUSIONS

Decreased expression of ZO-1, OCLN and MUC2, plus intestinal-microbiota dysbiosis, are associated with intestinal-barrier damage in IgAN rats.