Recombinant adeno-associated virus carrying thymosin β₄suppresses experimental colitis in mice

Abstract

AIMTo investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β4 (AAV-Tβ4) on murine colitis via intracolonic administration.METHODSAAV-Tβ4 was prepared and intracolonically used to mediate the secretory expression of Tβ4 in mouse colons. Dextran sulfate sodium (DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to establish a mouse colitis model resembling Crohn’s disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ4 on colitis. The activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis and proliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTSRecombinant AAVs efficiently delivered LacZ and Tβ4 into the colonic tissues of the mice, and AAV-Tβ4 led to a strong expression of Tβ4 in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ4-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ4 significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ4 also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSIONTβ4 exerts a protective effect on murine colitis, indicating that AAV-Tβ4 could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.

Preclinical Study in Vivo for New Pharmacological Approaches in Inflammatory Bowel Disease: A Systematic Review of Chronic Model of TNBS-Induced Colitis

“…Some authors use lower concentrations of ethanol because they want to avoid ethanol interference in inducing damage to the intestinal epithelium. Nevertheless, studies using ethanol at 50% as TNBS vehicle in colitis model already proved that ethanol does not affect in the observed colon lesion [67,70,71,72,75]. In our colitis model, the findings corroborate the same [20,21,22,23,24,25].…”

Anticolitic Effect of Berberine in Rat Experimental Model: Impact of PGE2/p38 MAPK Pathways

“…Our results revealed marked decline in GSH and suppressions of antioxidant enzymes paralleled with increase of MDA and NO levels in UC group. Zheng et al [ 40 ] stated the enhancement of oxidative stress by the excess secretion of MPO and proinflammatory cytokines such as TNF- α and IL-6 in colitis. SOD overwhelms excess superoxide radicals via its conversion to hydrogen peroxide (less toxic metabolite) and water, but CAT acts by conversion of hydrogen peroxide to water and molecular oxygen, so they provide mutual significant protection against reactive oxygen species.…”

Thymosin β4 suppresses CCl4‐induced murine hepatic fibrosis by down‐regulating transforming growth factor β receptor‐II

“…This requirement cannot be fulfilled using the usual commercially available vectors. In the process of constructing a recombinant AAV to mediate biologically active secretory expression of Tβ4, we used a novel secretory expression system in which the signal peptide and leader peptide of pro‐pre‐NT‐4 was fused to the N‐terminus of Tβ4 . This fusion pattern enabled the precise cleavage of the fusion protein to release Tβ4 with a Ser at its ultimate N‐terminus.…”