β2-AR信号通路影响表皮角质细胞可塑性及其在体表慢性创面治疗过程中的作用

Chronic wounds, including diabetic foot ulcers, venous leg ulcers, and pressure ulcers, often lead to tissue and organ defects that reduce quality of life. It has been estimated that 1 to 2% of the population in developed countries will experience a chronic wound in their lifetime. In China, the situation is more serious. An anticipated risk of diabetes and age-associated healing impairments dramatically contribute to the increased prevalence of chronic wounds. Not only are chronic wounds incredibly painful for patients, but they also require long-term treatment which present a substantial economic burden to the healthcare system. Wound healing is an intricate tissue remodeling process that is arbitrarily divided into three, overlapping phases, such as inflammation, tissue growth (proliferation) and tissue remodeling (maturation), and requires a coordinated interplay among cells, growth factors, and extracellular matrix proteins. Although healing is a consistent and regulated process, poor healing, however, increases the risk for wound infections or complications, lengthens hospital stays, magnifies patient discomfort, and slows return to activities of daily living. In this regard,, how to promote the regenerative capacity of surviving cells at the wound area and lead to functional recovery of wounded skin involved with sweat gland regeneration poses a great challenge for physicians and medical specialists. Converging evidence from different research paradigms suggest that neuroendocrine factors and their receptors participate in a complex network that modulates chronic wound healing. Described as the body's largest organ, the skin is strategically located at the interface with the external environment where it has evolved to detect, integrate and respond to a diverse range of stressors. The skin also functions as an important peripheral (neuro) endocrine organ that is tightly networked to central stress axes. In our previous study, we found an involvement of β2-AR signaling in the induction of EMT-like alterations in human keratinocytes in vitro. β2-AR signaling also affected HaCaT cell migration, resulting in faster closure on the wound gap as measured by in vitro scratch wound healing assay. Given the process of EMT portrays similar characteristics with “stemness” acquisition, the β2-AR/PKA/STAT3 cascade was therefore designed as an intervention to explore the mechanisms that regulate keratinocytes’ plasticity and cell-fate determination in this study, which will help to more clearly elucidate the pathways linking neuroendocrine factors and healing processes. Importantly, we constructed nanoparticles in targeted drug delivery by combining β2-AR agonist-PLGA microspheres with collagen sponge. Aiming at controlled release of the drug in the targeting wound, we tried to evaluate the role of β2-AR signaling on the healing outcome of chronic wounds. Based on these results, we further regulated the the plasticity of keratinocytes and promoted stemness via interactions of β2-AR signaling, which induced the reprogramming of keratinoctyes to sweat gland-like cells coupling with upregulation of ectodysplasin (EDA) expression levels in human epidermal keratinoctyes. Our results might shed new insight on precise control of the’ plasticity and fate determination of the surviving cells during chronic wound healing. Meanwhile, our study regarding to the neuroendocrine-controlled cell-fate modulation network also provides a novel target for therapeutic interventions during skin wound healing to rebulid the histological architecture and kinetics in reconstructed tissues, to restore normal function to damaged tissues, and ultimately reach the goal of perfect skin regeneration.

慢性创面不但影响患者生活质量，也给社会带来了沉重负担。创面修复是一个复杂过程涉及多种成分共同参与，因此如何引导创面内各细胞组分的可塑性，形成结构和功能兼备的组织替代物是慢性创面修复研究面临的难题之一。本项目基于我们前期关于神经-分泌通过调控表皮角质细胞（HEK）发生EMT样改变促进创面愈合、并调控HEK可塑性的工作基础，以β2-AR/PKA/STAT3为介入点，在研究β2-AR通路诱导HEK表型变化及命运转归相关分子机制的同时，构建纳米组装控释系统实现药物的靶向投递，客观地评价β2-AR通路在促进创面愈合及修复质量过程中的作用。在此基础上通过β2-AR通路干预HEK的可塑性使其获得干性，并联合基因编辑手段上调EDA的表达，诱导驯化HEK重编程为汗腺样细胞。本项目抓住了当前学科领域的关键问题，研究结果在理论及技术上的突破为促进慢性创面的功能性修复、实现多种组织原位同步再生奠定实验基础。

本项目面向再生医学与军事医学的重大需求，聚焦“汗腺再生与再造”这一前沿科学问题，深入探索神经-内分泌β2-AR信号通路在汗腺生理性发育及病理性再生中的作用。以满足临床治疗对结构及功能的双要求、提高患者生命质量为目标，将工程学、材料学的原理与技术与再生医学有机结合，以神经-内分泌 β2-AR 信号通路为切入点，构建汗腺精准重编程技术体系。发展集种子细胞规模化制备、功能化支架材料仿生制备、及二者有序装配为一体的促皮肤附件（汗腺）再生关键技术。在此基础上研发负载bFGF、可促慢性皮肤创面汗腺再生先进材料，并进入临床实验，辅助1例下肢静脉性溃疡患者的临床治疗。目前，本课题已发表SCI论文7篇，均在Biomaterials，Advanced Science，Signal Transduction and Targeted Therapy等高影响力国际期刊上发表。其中，关于激活 β2-AR 信号通路，构建汗腺精准重编程技术体系诱导表皮细胞转分化为功能性汗腺的研究论文已获国际生物工程顶级期刊Advanced Science正式发表，并被选为封面推介；关于生物材料负载技术重建组织内环境及其在汗腺再生及皮肤功能性修复中的重要作用相关论文已获国际生物医药顶级期刊Advanced Drug Delivery Reviews正式发表，他引130余次；关于应用生物材料重建组织微环境及其在汗腺再生领域的应用相关论文已获国际生物材料顶级期刊Biomaterials正式发表；关于应用仿生材料构建3D微环境及其在毛囊功能性再生领域的应用相关论文已获国际顶级期刊Signal Transduction and Targeted Therapy正式发表；核心技术申请专利5项，授权1项；参编专注2部，其中《烧伤、创伤、与再生医学》为国家卫计委“十二五”规划的研究生教材；获得临床伦理批件1份、临床病例报告1份；入选“国防卓青”，获军队军事科技进步一等奖、中国生物材料学会科学技术一等奖、解放军总医院科技进步一等奖等多项荣誉。培养博士研究生3名、硕士研究生6名。