Romaldini Alessio, Mastrogiacomo Maddalena, Cancedda Ranieri, Descalzi Fiorella
Department of Experimental Medicine (DIMES) and Department of Internal Medicine (DIMI), University of Genoa; Biotherapy Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
Front Bioeng Biotechnol. 2018 Dec 21;6:203. doi: 10.3389/fbioe.2018.00203. eCollection 2018.
Skin chronic wounds are non-healing ulcerative defects, which arise in association with a morbidity state, such as diabetes and vascular insufficiency or as the consequence of systemic factors including advanced age. Platelet Rich Plasma, a platelet-rich blood fraction, can significantly improve the healing of human skin chronic ulcers. Given that the subcutaneous adipose tissue is located beneath the skin and plays a role in the skin homeostasis, in this study, we investigated the response of human subcutaneous adipose tissue cells to platelet content in a model mimicking the milieu of a deep skin injury. Considering that, at the wound site, plasma turn to serum, platelets are activated and inflammation occurs, human adipose-derived stromal cells (hASC) were cultured with Human Serum (HS) supplemented or not with Platelet Lysate (PL) and/or IL-1α. We observed that HS sustained hASC proliferation more efficiently than FBS and induced a spontaneous adipogenic differentiation in the cells. PL added to HS enhanced hASC proliferation, regardless the presence of IL-1α. In the presence of PL, hASC progressively lessened the adipogenic phenotype, possibly because the proliferation of less committed cells was induced. However, these cells resumed adipogenesis in permissive conditions. Accordingly, PL induced in quiescent cells activation of the proliferation-related pathways ERK, Akt, and STAT-3 and expression of Cyclin D1. Moreover, PL induced an early and transient increase of the pro-inflammatory response triggered by IL-1α, by inducing COX-2 expression and secretion of a large amount of PGE, IL-6, and IL-8. Media conditioned by PL-stimulated hASC exerted a chemotactic activity on human keratinocytes and favored the healing of an scratch wound. In order to bridge the gap between results and possible events, the stimuli were also tested in cultures of human adipose tissue biopsies (hAT). PL induced cell proliferation in hAT and outgrowth of committed progenitor cells able to differentiate in permissive conditions. In conclusion, we report that the adipose tissue responds to the wound microenvironment by activating the proliferation of adipose tissue progenitor cells and promoting the release of factors favoring wound healing.
皮肤慢性伤口是不愈合的溃疡性缺损，其与诸如糖尿病和血管功能不全等发病状态相关联，或者是包括高龄在内的全身因素的结果。富血小板血浆，一种富含血小板的血液成分，能够显著改善人类皮肤慢性溃疡的愈合。鉴于皮下脂肪组织位于皮肤下方并在皮肤稳态中发挥作用，在本研究中，我们在模拟深度皮肤损伤环境的模型中研究了人类皮下脂肪组织细胞对血小板含量的反应。考虑到在伤口部位，血浆会转变为血清，血小板被激活且发生炎症，将人脂肪来源的基质细胞（hASC）与添加或不添加血小板裂解物（PL）和/或IL-1α的人血清（HS）一起培养。我们观察到，HS比胎牛血清更有效地维持hASC增殖，并诱导细胞自发的脂肪生成分化。添加到HS中的PL增强了hASC增殖，无论是否存在IL-1α。在存在PL的情况下，hASC逐渐减少脂肪生成表型，这可能是因为诱导了不太定向的细胞的增殖。然而，这些细胞在允许的条件下恢复了脂肪生成。相应地，PL诱导静止细胞中增殖相关途径ERK、Akt和STAT-3的激活以及细胞周期蛋白D1的表达。此外，PL通过诱导COX-2表达以及分泌大量PGE、IL-6和IL-8，诱导了由IL-1α触发的促炎反应的早期和短暂增加。由PL刺激的hASC条件培养基对人角质形成细胞发挥趋化活性，并有利于划痕伤口的愈合。为了弥合结果与可能事件之间的差距，还在人脂肪组织活检（hAT）培养物中测试了这些刺激。PL诱导hAT中的细胞增殖以及能够在允许条件下分化的定向祖细胞的生长。总之，我们报告脂肪组织通过激活脂肪组织祖细胞的增殖并促进有利于伤口愈合的因子的释放来响应伤口微环境。
