Characterization of persistent hyperemic foci and their role in photocarcinogenes

持续充血病灶的特征及其在光致癌物中的作用

• 批准号: 8529530
• 负责人: RAYMOND L KONGER
• 金额: $ 18.76万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-13 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8529530
• 关键词: Aging; Animals; Anti-Inflammatory Agents; Appearance; Area; CDKN2A gene; Carcinogen exposure; Carcinogens; Cell Aging; Cells; Characteristics; Chemicals; Chemopreventive Agent; Chronic; Clinical; Coupled; DNA; DNA Damage; DNA Double Strand Break; Dermal; Dermis; Development; Disease; Dose; Epidermis; Epithelial; Epithelium; Excision; Exhibits; Fibroblasts; Figs - dietary; Frequencies; Future; Gene Mutation; Hemoglobin; Heterochromatin; Human; Hyperemia; Hyperplasia; Image; Imaging technology; Inbred HRS Mice; Individual; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Response; Interleukin-8B Receptor; Lead; Left; Lesion; Life; Link; Malignant Neoplasms; Maps; Measurement; Measures; Mediating; Methods; Microscopic; Modeling; Monitor; Mus; Mutation; Oxidative Stress; Phenotype; Premalignant Change; Probability; Production; Proteins; Protocols documentation; Role; Sampling; Shuttle Vectors; Signal Transduction; Skin; Skin Cancer; Source; Sun Exposure; The Sun; Time; Tissues; Transgenic Mice; Ultraviolet Rays; Vascular blood supply; angiogenesis; bioimaging; carcinogenesis; celecoxib; chemical carcinogen; chemokine; cytokine; high risk; insight; keratinocyte; mouse model; neoplastic; novel; novel strategies; oxidative DNA damage; pressure; response; senescence; spatiotemporal; therapeutic target; therapy design; tool; tumor; tumorigenesis; ultraviolet

DESCRIPTION (provided by applicant): Chronic inflammation promotes DNA damage to overlying epithelium and is frequently associated with neoplastic disease. In addition, DNA damage to epithelial tissues results in the release of a number of cytokines and chemokines that promote an inflammatory response. In particular, a persistent DNA damage response (PDDR) leading to cellular senescence is particularly potent in producing a sustained source of pro- inflammatory mediators; this response has been called the senescence associated secretory phenotype (SASP). It would therefore seem reasonable that a self-perpetuating cycle of DNA damage/SASP and inflammation could occur that would lead to continuing mutation pressure in overlying epithelium. Our proposed studies will examine this linkage. This is possible due to a novel bioimaging approach that monitors dermal microvascular hemoglobin (Hgb) content. We show that focal areas of hyperemia occur following the application of chemical carcinogens or ultraviolet (UV) light to mouse skin. Hyperemia preceded tumor formation, tumors were found to invariably occur in these areas of hyperemia, and these areas were seen to persist and expand following the cessation of an initial carcinogenic UV exposure. Only areas with increased hyperemia were associated with epidermal hyperplasia and dermal inflammation. Moreover, celecoxib, a known anti-inflammatory agent, was shown to suppress these areas of hyperemia along with subsequent tumor formation. We hypothesize that initial carcinogenic exposures elicit a PDDR coupled SASP in epithelial or dermal cells that then drive a self- perpetuating cycle of DNA damage/dermal inflammatory angiogenesis that precedes neoplastic development. We will utilize our unique bioimaging strategy to examine this idea in two aims. In the first aim, we will expose mice to a carcinogenic dose of UV of limited duration, then map out early changes in microvascular blood supply. We will then verify that hyperemic areas correspond to zones of inflammatory angiogenesis that precede microscopic or macroscopic neoplastic disease. We will also determine whether these hyperemic zones exhibit enrichment for characteristic SASP inflammatory mediators. In the second aim, we will examine whether the epidermis overlying early hyperemic areas exhibit increased mutations of the key DNA damage regulator, p53, which is known to augment the SASP response. Moreover, we will determine whether dermal fibroblasts or epidermal keratinocytes in early hyperemic foci exhibit a senescence marker, heterochromatin protein 1g (HP1g), and markers of double stranded DNA breaks, gH2AX and p53BP1. In addition, using a transgenic mouse model (Big Blue mice), we will determine whether hyperemic areas are associated with increased epidermal mutation frequency and whether this mutation pressure persists in the absence of further UV exposures. In both aims, we will examine the capacity of two anti-inflammatory agents (celecoxib and a CXCR2 receptor antagonist) to suppress the formation of hyperemic foci and the associated features of inflammation, senescence and increased epidermal mutation pressure.

描述（由申请人提供）：慢性炎症会促进上皮细胞的 DNA 损伤，并且经常与肿瘤性疾病相关。此外，上皮组织的 DNA 损伤会导致许多细胞因子和趋化因子的释放，从而促进炎症反应。特别是，导致细胞衰老的持续DNA损伤反应（PDDR）对于产生持续的促炎介质来源特别有效。这种反应被称为衰老相关分泌表型（SASP）。因此，DNA 损伤/SASP 和炎症的自我延续循环可能会发生，这将导致上皮细胞中持续的突变压力，这似乎是合理的。我们提出的研究将检验这种联系。这得益于一种监测真皮微血管血红蛋白 (Hgb) 含量的新型生物成像方法。我们发现，在小鼠皮肤上使用化学致癌剂或紫外线 (UV) 后，会出现局部充血现象。充血先于肿瘤形成，发现肿瘤总是发生在这些充血区域，并且在最初的致癌紫外线照射停止后，这些区域持续存在并扩大。只有充血增加的区域才与表皮增生和真皮炎症相关。此外，塞来昔布（一种已知的抗炎药）被证明可以抑制这些区域的充血以及随后的肿瘤形成。我们假设最初的致癌暴露会在上皮细胞或真皮细胞中引发 PDDR 偶联的 SASP，然后在肿瘤发展之前驱动 DNA 损伤/真皮炎症血管生成的自我延续循环。我们将利用我们独特的生物成像策略从两个目标来检验这个想法。第一个目标是，我们将让小鼠在有限时间内暴露于致癌剂量的紫外线下，然后绘制出微血管血液供应的早期变化。然后我们将验证充血区域对应于微观或宏观肿瘤疾病之前的炎症血管生成区域。我们还将确定这些充血区是否表现出特征性 SASP 炎症介质的富集。在第二个目标中，我们将检查覆盖早期充血区域的表皮是否表现出关键 DNA 损伤调节因子 p53 的突变增加，众所周知，p53 会增强 SASP 反应。此外，我们将确定早期充血灶中的真皮成纤维细胞或表皮角质形成细胞是否表现出衰老标记物异染色质蛋白 1g (HP1g) 以及双链 DNA 断裂标记物 gH2AX 和 p53BP1。此外，使用转基因小鼠模型（Big Blue 小鼠），我们将确定充血区域是否与表皮突变频率增加相关，以及在没有进一步紫外线照射的情况下这种突变压力是否持续存在。在这两个目标中，我们将检查两种抗炎药（塞来昔布和 CXCR2 受体拮抗剂）抑制充血灶形成以及炎症、衰老和表皮突变压力增加的相关特征的能力。