Novel Mechanisms of Regenerative Tissue Repair

项目摘要 产后皮肤损伤愈合后留下疤痕，造成重大的健康、心理和经济负担。我们 研究小组研究了胎儿再生组织修复的机制，最终目标是开发抗- 纤维化治疗在追求这一使命和以前的R 01支持，我们的团队已经（i）发现IL-10是 胎儿伤口修复的关键调节因子，并促进无瘢痕愈合，（ii）复制胎儿无瘢痕表型 通过在出生后皮肤伤口上应用IL-10，（iii）揭示了控制细胞外 通过高分子量透明质酸（HMW-HA）信号传导的基质（ECM）重塑和新血管形成， (iv)表明HMW-HA驱动T淋巴细胞介导的IL-10表达，（v）最近报道， 小鼠皮肤伤口中主要是CD 4 + T淋巴细胞的时间流入与 伤口愈合的增殖和重塑阶段，以及（vi）获得的证据表明， 过继转移功能性CD 4 + T淋巴细胞对重症联合免疫缺陷小鼠免疫作用 显著减少炎症，减少纤维化，并愈合损伤后皮肤伤口， 疤痕虽然我们的集体数据强烈表明，一致的HMW-HA介导的IL-10依赖性串扰 成纤维细胞和动员的T淋巴细胞之间的损伤反应，很少有人知道的身份， 产生IL-10的CD 4 + T淋巴细胞亚群及其对皮肤伤口修复结果的作用我们 假设：（a）CD 4+淋巴细胞亚群通过IL-10- 依赖性信号传导和（B）HA和透明质酸粘附素β信号传导，以驱动通过CD 4+细胞产生IL-10 淋巴细胞，从而减少疤痕的风险。为了获得支持我们假设的实验证据， 为设计有效的抗疤痕疗法提供了令人信服的线索，我们提出了三个具体目标。在目标1中，我们 将确定产生IL-10的CD 4 + T淋巴细胞亚群调节炎症、ECM 形成和血管生成以减少体外和体内的瘢痕形成。在这一目标和随后的目标中，我们将 使用独特的10 Bit 4小鼠模型，该模型设计有三重报告系统- IL-4（RFP）、Il-10（CD90.1）和 Foxp 3（GFP）-明确评估不同T淋巴细胞亚群的需求，推测这些T淋巴细胞亚群 抗疤痕功能。在目的2中，我们将研究HA如何调节CD 4+淋巴细胞的产生， IL-10通过CD 44信号传导，并确定HA稳定透明质酸粘附素如何影响这种信号级联。 最后，在目标3中，我们将确定HA介导的内源性IL-10产生是否可以指导成人成纤维细胞 向胎儿样再生表型的方向发展，以及这种信号传导是否可以影响人类瘢痕形成表型。 利用我们所获得的知识，我们将优化一个翻译的HMW-HA为基础的水凝胶治疗系统 促进皮肤伤口中CD 4+淋巴细胞稳定产生IL-10，并测试其对瘢痕形成的影响 临床前伤口愈合模型的结果。总的来说，提出的目标将揭示新的CD 4+淋巴细胞 本发明提供了一种用于伤口愈合的新的转化生理学，并导致一种新的转化治疗范例以减轻皮肤瘢痕形成。

PROJECT SUMMARY Postnatal dermal injuries heal with scars, resulting in major health, psychosocial and economic burdens. Our team has studied the mechanisms of fetal regenerative tissue repair with the ultimate goal to develop anti- fibrotic therapies. In pursuit of this mission and with previous R01 support, our team has (i) found that IL-10 is a key regulator of fetal wound repair and promotes scarless healing, (ii) replicated the fetal scarless phenotype by application of IL-10 on postnatal dermal wounds, (iii) revealed new mechanisms that control extracellular matrix (ECM) remodeling and neovascularization via high molecular weight hyaluronan (HMW-HA) signaling, (iv) demonstrated that HMW-HA drives T lymphocyte-mediated IL-10 expression, (v) recently reported a temporal influx of predominantly CD4+ T lymphocytes in murine skin wounds that correlated with the proliferative and remodeling phases of wound healing, and (vi) obtained evidence that reconstitution of immunity by adoptive transfer of functional CD4+ T lymphocytes in severe combined immune deficient mice significantly reduced inflammation, decreased fibrosis, and healed post-injury dermal wounds with less scarring. While our collective data strongly suggest a concerted HMW-HA-mediated IL-10-dependent crosstalk between fibroblast cells and mobilized T lymphocytes in response to injury, little is known about the identity of IL-10-producing CD4+ T lymphocyte subsets and how they contribute to dermal wound repair outcomes. We hypothesize that: (a) CD4+ lymphocyte subsets differentially regulate postnatal dermal scarring via IL-10- dependent signaling and (b) HA and the hyaladherins transduce signals to drive IL-10 production by CD4+ lymphocytes, which reduces scarring risks. To obtain experimental evidence that supports our hypothesis and provides compelling clues to design effective anti-scar therapies, we propose three specific aims. In aim 1, we will identify the mechanisms by which IL-10-producing CD4+ T lymphocyte subsets regulate inflammation, ECM formation and angiogenesis to reduce scar formation in vitro and in vivo. In this and subsequent aims, we will use unique 10Bit4 mouse models engineered with a triple reporter system - IL-4 (RFP), Il-10 (CD90.1), and Foxp3 (GFP) - to unambiguously assess the requirement of different T lymphocyte subsets presumed to transduce anti-scar functions. In aim 2, we will investigate how HA regulates CD4+ lymphocyte production of IL-10 via CD44 signaling, and determine how HA-stabilizing hyaladherins influence this signaling cascade. Finally in aim 3, we will determine if HA-mediated endogenous IL-10 production can direct adult fibroblasts toward a fetal-like regenerative phenotype and if this signaling can influence human scarring phenotypes. Using our gained knowledge, we will then optimize a translational HMW-HA-based hydrogel treatment system to promote stable IL-10 production by CD4+ lymphocytes in dermal wounds and test its effects on scarring outcomes in a preclinical wound healing model. Overall, the proposed aims will reveal new CD4+ lymphocyte physiology in wound healing and lead to a novel translational treatment paradigm to mitigate dermal scarring.