Pharmaceutical grade synthetic peptide Thr-Glu-Lys-Lys-Arg-Arg-Glu-Thr-Val-Glu-Arg-Glu-Lys-Glu ameliorates DSS-induced murine colitis by reducing the number and pro-inflammatory activity of colon tissue-infiltrating Ly6G+ granulocytes and Ly6C+ monocytes.

A pharmaceutical grade synthetic tetradecapeptide Thr-Glu-Lys-Lys-Arg-Arg-Glu-Thr-Val-Glu-Arg-Glu-Lys-Glu (GEPON) that mimics the ezrin protein hinge region was studied in dextran sodium sulphate-induced murine experimental colitis (DSS colitis). We report that GEPON intraperitoneal injections significantly attenuated DSS-induced pathological manifestations in the large intestine, bloody diarrhoea, and body weight loss in C57BL/6 mice. GEPON markedly inhibited the transcription rate of pro-inflammatory Il1b, Il6, and Nos2 genes in the colon tissue, in contrast with those encoding anti-inflammatory factors, such as Tgfb1, I10, and Arg1, whose transcription rate did not change significantly. Using flow cytometry, we found that GEPON treatment significantly reduced the accumulation of Ly6G+ granulocytes and Ly6C+ monocytes in the colon infiltrate of DSS colitis mice. Analysis of the mRNA level in myeloid cells sorted from the colon tissue revealed that GEPON had decreased the expression of pro-inflammatory genes in both colon-infiltrating Ly6G+ granulocytes and Ly6C+ monocytes, but not in Ly6C-CD64+ macrophages of DSS-treated mice. The direct anti-inflammatory impact of GEPON was shown in an in vitro culture of Ly6C+ monocytes, as evidenced by an inhibition of IL-1 beta and IL-6 mRNA expression. Taken together, our results demonstrated that GEPON had a pronounced therapeutic effect on ulcerative colitis in a laboratory mice model and provided evidence of its curative efficacy via inhibition of colon tissue inflammation by decreasing Ly6G+ granulocyte and Ly6C+ monocyte infiltration and by reducing their pro-inflammatory activities.

Synthetic peptide TEKKRRETVEREKE derived from ezrin induces differentiation of NIH/3T3 fibroblasts.

Synthetic 14 AA peptide (Gepon) derived from the hinge region of ezrin, a protein that links cell surface molecules to intracellular actin filaments, accelerates and facilitates wound and ulcer healing in clinical applications. However, the molecular mechanisms underlying this phenomenon and involved in enhanced healing of wounds with Gepon are not yet understood. The purpose of current study was to investigate intracellular signaling pathways involved in the effect of this peptide on wild type and genetically modified (CD44 KO) NIH/3T3 embryonic mouse fibroblasts. Gepon treatment of NIH/3T3 cells resulted in morphological and biochemical changes, characteristic of differentiated fibroblasts. While treatment of NIH/3T3 cells with TGF-ß1 triggered the activation of both canonical and non-canonical signaling pathways, exposure of fibroblasts to Gepon activated only the ERK1/2 dependent pathway without modulating SMAD dependent signaling pathway. Knocking out hyaluronic acid CD44 receptor did not change Gepon or TGF-ß1 dependent activation of intracellular signaling pathways and assembling of α-SMA-positive filaments. Gepon dependent differentiation of NIH/3T3 fibroblasts is based on activation of ERK1/2 kinase, non-canonical intracellular signaling pathway. Our data suggest that the treatment of fibroblasts with Gepon triggers activation of the non-canonical (SMAD independent) intracellular signaling pathway that involves ERK1/2kinase phosphorylation. Activation of the MAPK signaling pathway and the increase in formation of α-SMA containing stress filaments induced by Gepon were independent on presence of CD44 receptor in NIH/3T3 fibroblasts. Thus, our observation designates the significance and sufficiency of MAPK pathway mediated activation of fibroblasts with Gepon for healing of erosion, ulcers and wounds.