Influence of scratching on skin profiles in chronic pruritus patients

抓挠对慢性瘙痒症患者皮肤轮廓的影响

• 批准号: 399404657
• 负责人: Dr. Konstantin Agelopoulos
• 金额: --
• 依托单位: Klinik für Hautkrankheiten
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/399404657?language=en
• 关键词: Influence; scratching; skin; profiles; chronic

Chronic pruritus (CP) is a highly prevalent symptom of different diseases and constitutes a high burden of suffering for patients. Still, little is known about the underlying pathways. This holds especially true for the mechanisms involved in scratching. Scratching reliefs pruritus but, in CP, it can result in damage of the skin integrity, anatomy and function. The influence of scratching on the cutaneous cellular and molecular mechanisms have been investigated in the first funding period of PRUSEARCH and CP-differentiating branching pattern and gene expression have been found. In this project, we aim to analyze in-depth the epidermal neuroanatomical alterations, and neuronal and non-neuronal pruritic markers that are induced by scratching. We will further investigate the effect of chronic mechanical stress (as equivalent for scratching) on gene expression regarding factors contributing to nerve fiber alterations and metabolism of keratinocytes and we will define the role of long-term modifying factors of gene expression in maintaining chronicity of pruritus.We will recruit patients with chronic nodular prurigo (CNPG, syn: prurigo nodularis; as a model for severe scratch-related skin lesions), atopic dermatitis (AD; in order to connect to data obtained in the first funding period) and corresponding healthy volunteers (in total 180 participants). Using skin biopsies of (a) pruritic, chronically scratched, (b) pruritic, unscratched and (c) not-pruritic, normal skin, we will morphologically characterize the neuroanatomy of the cutaneous nerve fibers and expression of pruritogenic markers. We will isolate keratinocytes to analyze in vitro the effect of chronic mechanical stress on gene expression. This will be done by means of mRNA sequencing with focus on neuroplasticity-related genes. Comparison of the different areas will enable us to identify a priming effect of pruritus and chronic scratching on these cells. Co-culture of neuronal cells and the keratinocytes will be used for functional validation of candidate genes defined within the first funding period. We will use spiking or depletion in media (secreted proteins) or modulation of gene expression. To obtain a functional correlate in the scratched and unscratched skin, focal electrical stimulation will be performed for selective nociceptor stimulation. Finally, DNA methylation signatures will be defined for the different CP entities as well as for chronic scratching. Analyzing same biopsies will allow to define impact of DNA methylation on gene expression profiles and by this on maintaining chronicity.In sum, we aim to identify the causal relationships between the scratching-related factors and morphological changes, clinical pruritus characteristics obtained via questionnaires and functional parameters. The findings will have an important translational impact by defining molecular factors which are related to chronic scratching and which open novel therapeutically strategies.

慢性瘙痒症（CP）是多种疾病的常见症状，给患者带来沉重的痛苦负担。尽管如此，人们对潜在的途径知之甚少。对于涉及抓挠的机制尤其如此。抓挠可以缓解瘙痒，但对于脑瘫患者来说，抓挠可能会导致皮肤完整性、解剖结构和功能受损。 PRUSEARCH 的第一期资助期间研究了抓挠对皮肤细胞和分子机制的影响，并发现了 CP 分化的分支模式和基因表达。在这个项目中，我们的目标是深入分析抓挠引起的表皮神经解剖学改变以及神经元和非神经元瘙痒标志物。我们将进一步研究慢性机械应力（相当于抓挠）对神经纤维改变和角质形成细胞代谢相关因素的基因表达的影响，并且我们将定义基因表达的长期修饰因素在维持瘙痒慢性中的作用。我们将招募慢性结节性痒疹（CNPG，同义词：结节性痒疹；作为模型 严重的抓伤相关皮肤损伤）、特应性皮炎（AD；以便连接到第一个资助期获得的数据）以及相应的健康志愿者（总共 180 名参与者）。使用（a）瘙痒、长期抓伤、（b）瘙痒、未抓伤和（c）非瘙痒、正常皮肤的皮肤活检，我们将从形态学上表征皮肤神经纤维的神经解剖学和致痒标记物的表达。我们将分离角质形成细胞，以在体外分析慢性机械应力对基因表达的影响。这将通过 mRNA 测序来完成，重点关注神经可塑性相关基因。不同区域的比较将使我们能够确定瘙痒和慢性抓挠对这些细胞的启动效应。神经元细胞和角质形成细胞的共培养将用于第一个资助期内定义的候选基因的功能验证。我们将使用介质（分泌蛋白）中的加标或耗尽或基因表达的调节。为了获得划伤和未划伤皮肤的功能相关性，将进行局部电刺激以进行选择性伤害感受器刺激。最后，将为不同的 CP 实体以及慢性抓挠定义 DNA 甲基化特征。分析相同的活检将能够确定 DNA 甲基化对基因表达谱的影响，从而确定对维持慢性性的影响。总之，我们的目标是确定抓挠相关因素与形态变化、通过问卷获得的临床瘙痒特征和功能参数之间的因果关系。通过定义与慢性抓伤相关的分子因素并开辟新的治疗策略，这些发现将产生重要的转化影响。