Characterization of biological effects of KdPT on epithelial barrier function and wound healing

炎症性肠病的治疗选择仍然有限。以前，我们可以鉴定出α-黑素细胞刺激激素的抗炎三肽衍生物Lys-d-Pro-Thr（KdPT），其在各种结肠炎实验小鼠模型中具有有希望的保护作用。基于这些开创性结果，目前正在溃疡性结肠炎患者中进行II期多中心临床试验。值得注意的是，KdPT的抗炎作用不仅限于肠道。我们可以表明，KdPT抑制典型的NF-κ B信号在SZ 95 sebocytes，一个永生化的人类上皮sebocytes细胞系经常被用作痤疮，最常见的炎症性皮肤病的体外模型。有趣的是，KdPT可能通过调节不同的紧密连接（TJ）蛋白的表达和/或定位，进一步促进肠上皮细胞的增殖和增强肠屏障功能。(2)我们将采用鼠结肠镜检查研究肽在体内是否促进机械诱导的结肠伤口的愈合。(3)为了测试KdPT是否在炎症环境中促进皮肤中的伤口愈合，我们将研究在IL-1 β和TNF-α存在下肽对人表皮角质形成细胞以及3D人皮肤等同物的影响。(4)最后，将在存在上述促炎细胞因子的情况下在人表皮角质形成细胞中检查KdPT对屏障功能读数、TJ蛋白的表达或定位以及NF-κ B活化的影响。最后一个目标将在很大程度上通过分享实验方法之间的两个跨学科的项目部分。总之，这些临床前实验被认为是提供了一个非常有前途的基础，为进一步开发KdPT在胃肠病学和皮肤病学领域。

The treatment options for inflammatory bowel diseases are still limited. Previously, we could identify an anti-inflammatory tripeptide derivative of alpha-melanocyte-stimulating hormone, Lys-d-Pro-Thr (KdPT), with promising protective effects in various experimental mouse models of colitis. Based on these pioneering results a phase II multi-center clinical trial is currently conducted in patients with colitis ulcerosa. Notably, the anti-inflammatory effects of KdPT are not limited to the gut. We could show that KdPT suppresses canonical NF-KappaB signalling in SZ95 sebocytes, an immortalized human epithelial sebocytes cell line frequently used as an vitro model of acne, the most common inflammatory skin disease. Interestingly, KdPT further increased proliferation and augmented barrier function of intestinal epithelial cells possibly by modulating expression and/or localization of distinct Tight Junction (TJ) proteins.Based on these encouraging findings we want to decipher in the present research project (1) the molecular mechanism by which KdPT increases intestinal barrier function. (2) We will investigate if the peptide in vivo promotes healing of mechanically-induced colonic wounds employing murine coloscopy. (3) To test as to whether KdPT promotes wound healing in the skin in an inflammatory setting we will investigate the impact of the peptide in presence of IL-1beta and TNF-alpha on human epidermal keratinocytes as well as in 3D human skin equivalents. (4) Finally, the effect of KdPT on barrier function readouts, expression or localization of TJ proteins, and NF-KappaB activation will be examined in human epidermal keratinocytes in presence of the above proinflammatory cytokines. The last objective will be largely facilitated by sharing experimental methods between the two interdisciplinary parts of the project. Taken together, these preclinical experiments are believed to provide a very promising base for the further exploitation of KdPT in the field of both gastroenterology and dermatology.