Mechanistic understanding of the effect of light (Visible & Blue light) on the body's internal clock and its associated skin functions.

所有的哺乳动物系统在系统、器官和细胞水平上都遵循一个昼夜循环。即使是皮肤和毛细胞，也有自己独立的内部时钟，所有这些都是由昼夜节律基因或时钟基因驱动的。在白天，皮肤昼夜节律基因促进皮肤保护性反应，在晚上调节对白天暴露在外部环境中的损伤的修复。目前的生活方式和过度暴露于外部因素，如光和污染，会影响人体的内在时钟，从而影响其相关功能。包括联合利华和Birch-Machin在内的多个实验室的科学家已经开始探索紫外线以外的太阳光谱的作用，以了解可见光对人类皮肤的影响。联合利华的研究表明，在体外和体内条件下，可见光，特别是HEV蓝光比绿光和红光影响更大。Birch Machin的团队展示了阳光的可见光和红外成分与紫外线对皮肤真皮成纤维细胞的直接协同作用。基因芯片数据表明，光影响多种途径，如自噬、氧化应激、线粒体功能和昼夜节律，特别是皮肤相关的夜间修复机制。某些生活方式、环境因素、过度使用电子设备、延迟的睡眠习惯似乎会调节身体的昼夜节律，这可能会直接或间接地影响皮肤自身的生物钟和功能。因此，需要对光和皮肤之间的相互作用以及是什么感觉和驱动可见光/蓝光对皮肤昼夜节律功能的影响进行强有力的分子理解，才能利用目前的防晒霜和夜间护肤霜来全面保护皮肤。通过这个项目，我们将试图解开分子机制和途径，然后可以有针对性地提供保护/修复/重置皮肤时钟，在这个不断变化和挑战的世界中。目的-1：确定光感受器(Opsins)在调节皮肤昼夜节律及其相关昼夜功能中的作用。视蛋白受体在皮肤细胞中表达，并激活光诱导通路。最近的研究表明，视蛋白受体3通过与MC1R受体结合，在调节肤色动态平衡方面发挥着重要作用。因此，我们将研究可见光和紫外线(单独和联合)对不同类型Fitzpatrick皮肤细胞Opsin3/5表达和活性的影响，并将利用各种分子和细胞生物学方法研究其在色素沉着、线粒体生物学和皮肤夜间修复功能中的调节作用。目的2：探索蓝光微阵列数据，了解其在皮肤昼夜节律及其下游相关功能中的意义。我们将建立在现有的关于蓝光对成纤维细胞影响的转录数据的基础上，使用RNAseq技术将进一步验证这些发现，特别是通过使用分子方法来验证昼夜节律调节皮肤的夜间功能。此外，新发现的与昼夜节律和皮肤夜间功能有关的表达标记物将在生理剂量的蓝光照射后的角质形成细胞中进行研究。目的3：了解蓝光对皮肤生物能量学的调节机制。线粒体呼吸链复合体的表达和线粒体功能的测量也将通过特定的功能分析和海马生物分析仪来确定，以评估OXPHOS和糖酵解活性与皮肤生物能量和健康的关系。目的-4：研究防晒霜和生物活性组合如何影响上述细胞通路的调节。

All mammalian systems follow a diurnal cycle at systemic, organ and cellular level. Even, skin and hair cells, have its own independent internal clock, all of which is driven by the circadian rhythm genes or clock genes. During the daytime, skin circadian rhythm gene promotes skin protective responses and at night regulates repair of the damages from the daytime exposure to external environment. The current lifestyle and excessive exposure to external factors like light and pollution impacts the body's internal clock and therefore its associated functions. Scientists in various labs including in Unilever & Birch-Machin's, have begun to explore the role of sun spectrum beyond UV to understand the effect of visible light on human skin. Unilever studies showed that visible light especially HEV blue light impacts more than green and red light in in vitro and in vivo conditions. Birch Machin's group demonstrated direct synergistic interaction of the visible and IR components of sunlight with UV on skin dermal fibroblasts. Microarray data indicates that light impacts multiple pathways such as autophagy, oxidative stress, mitochondrial function, and circadian rhythm especially the skin associated night repair mechanisms. The implication of certain lifestyle, environmental factors, excessive use of digital devices, delayed sleep habits seem to modulate bodies circadian rhythm which may have direct and indirect impact on skin's own biological clock & functions. Therefore, a robust molecular understanding of the interactions between light and skin and what senses and drives the visible/blue light effect on the skin circadian rhythm functions is needed to build on the benefit of current sunscreens and night skin care creams for total protection of skin. Through this project we would try to unravel the molecular mechanisms and pathways which can then be targeted to deliver protection/restoration/resetting the skin clock against the exposomes in this ever changing and challenging world.Objective-1:To determine the role of photoreceptors (Opsins) in regulating skin circadian rhythm and its associated day and night functions. Opsin receptors are expressed in skin cells and activates light induced pathways. Recent studies suggests that opsin receptor 3 play a very important role in regulating skin colour homeostasis by binding to MC1R receptor. Hence, we would be studying the effect of visible light and UV (alone and in combination) on the expression and activity of Opsin3/5 in various Fitzpatrick skin types and skin cells and its role in the regulation of pigmentation, mitochondrial biology and skin night repair functions will be studied using various molecular and cell biology methods.Objective-2:Exploring blue light microarray data to understand its implications in skin circadian rhythm and its downstream associated functions. We will build on the existing transcriptomic data that exist on the effect of bluelight on fibroblasts and using RNAseq technology will further validate the findings, especially on the circadian rhythm regulated skin's night functions by using molecular methodologies. In addition, the newly identified expression markers particularly involved in circadian rhythm and skin's night functions will be studied in keratinocytes following exposure to physiological dose of blue light.Objective-3:Mechanistic understanding on the regulation of skin bioenergetics by blue light. The expression of mitochondrial respiratory chain complexes and measurement of mitochondrial function will also be determined by specific functional assays and the Seahorse bioanalyzer to assess OXPHOS and glycolytic activity in relation to skin bioenergy and health. Objective-4:Investigate how sunscreens and bioactive combination affect the modulation of the cellular pathways identified above.