Park Hyunju, An Eunjin, Cho Lee Ae-Ri
College of Pharmacy, Duksung Women's University, 33 Samyang-ro144-gil, Dobong-gu, Seoul, 01369 Korea.
Tissue Eng Regen Med. 2017 Jan 19;14(1):73-80. doi: 10.1007/s13770-016-0017-y. eCollection 2017 Feb.
To evaluate whether Palmitoyl-pentapeptide (Pal-KTTKS), a lipidated subfragment of type 1 pro-collagen (residues 212-216), plays a role in fibroblast contractility, the effect of Pal-KTTKS on the expression of pro-fibrotic mediators in hypertropic scarring were investigated in relation with trans-differentiation of fibroblast to myofibroblast, an icon of scar formation. α-SMA was visualized by immunofluorescence confocal microscopy with a Cy-3-conjugated monoclonal antibody. The extent of α-SMA-positive fibroblasts was determined in collagen lattices and in cell culture study. Pal-KTTKS (0-0.5 µM) induced CTGF and α-SMA protein levels were determined by western blot analysis and fibroblast contractility was assessed in three-dimensional collagen lattice contraction assay. In confocal analysis, fibroblasts were observed as elongated and spindle shapes while myofibroblast observed as squamous, enlarged cells with pronounced stress fibers. Without Pal-KTTKS treatment, three quarters of the fibroblasts differentiates into the myofibroblast; α-SMA-positive stress fibers per field decreased twofold with 0.1 µM Pal-KTTKS treatment (75 ± 7.1 vs 38.6 ± 16.1%, n = 3, < 0.05). The inhibitory effect was not significant in 0.5 µM Pal-KTTKS treatment. Stress fiber level and collagen contractility correlates with α-SMA expression level. In conclusion, Pal-KTTKS (0.1 µM) reduces α-SMA expression and trans-differentiation of fibroblasts to myofibroblast. The degree of reduction is dose-dependent. An abundance of myofibroblast and fibrotic scarring is correlated with excessive levels of α-SMA and collagen contractility. Delicate balance between the wound healing properties and pro-fibrotic abilities of pentapeptide KTTKS should be considered for selecting therapeutic dose for scar prevention.
为了评估棕榈酰五肽(Pal-KTTKS),即I型前胶原的脂化亚片段(第212 - 216位氨基酸残基)是否在成纤维细胞收缩中发挥作用,研究了Pal-KTTKS对肥厚性瘢痕中促纤维化介质表达的影响,并将其与成纤维细胞向肌成纤维细胞的转分化(瘢痕形成的一个标志)相关联。使用Cy-3偶联的单克隆抗体通过免疫荧光共聚焦显微镜观察α-平滑肌肌动蛋白(α-SMA)。在胶原晶格和细胞培养研究中确定α-SMA阳性成纤维细胞的程度。通过蛋白质印迹分析确定Pal-KTTKS(0 - 0.5 μM)诱导的结缔组织生长因子(CTGF)和α-SMA蛋白水平,并在三维胶原晶格收缩试验中评估成纤维细胞的收缩性。在共聚焦分析中,成纤维细胞呈细长的纺锤形,而肌成纤维细胞呈鳞状、增大的细胞,具有明显的应力纤维。未经Pal-KTTKS处理时,四分之三的成纤维细胞分化为肌成纤维细胞;用0.1 μM Pal-KTTKS处理后,每视野α-SMA阳性应力纤维减少两倍(75 ± 7.1%对38.6 ± 16.1%,n = 3,P < 0.05)。在0.5 μM Pal-KTTKS处理中,抑制作用不显著。应力纤维水平和胶原收缩性与α-SMA表达水平相关。总之,Pal-KTTKS(0.1 μM)可降低α-SMA表达和成纤维细胞向肌成纤维细胞的转分化。降低程度呈剂量依赖性。大量的肌成纤维细胞和纤维化瘢痕与α-SMA和胶原收缩性的过度水平相关。在选择预防瘢痕的治疗剂量时,应考虑五肽KTTKS在伤口愈合特性和促纤维化能力之间的微妙平衡。