Iyengar Bhanu
Pigment Cell Centre, Iyengar Farm, Brijwasan Road, PO Kapshera, New Delhi, 110037 India.
Springerplus. 2013 Apr 12;2(1):158. doi: 10.1186/2193-1801-2-158. Print 2013 Dec.
The pigment cells form the largest population of neural crest cells to migrate into the epidermis and hair follicle along each dermatomic area from the neural folds. The melanopsin system responsible for photoentrainment, was isolated from the photosensitive dermal melanophores of frogs Xenopus laevis responding to light. Melanocytes form a photoresponsive network which reads the environmental seasonal variations in the light cycles in the same manner. The present work was undertaken to study the organization of this system by: I. Experimental assessment of photoresponse and II. Evidence of an organized system of photoreception in the skin. Melanocytes, in whole skin organ cultures and epidermal strips, from margin of vitiligo in G2 phase show prominent dendricity, and express pigment, biogenic amines and hormones on UV exposure. The photoresponse depends on the photosensitive enzymes NAT/HIOMT and dopaoxidase. Melanocytes interact with adjacent keratinocytes, dermal capillaries, and nerve endings. The melanocyte network reads the diurnal and seasonal photophase by the melatonin/serotonin switch like the pineal. Sleep disorders and winter depression are corrected by phototherapy utilising this mechanism. Melanocytes showing photoactivity, aplasia, hypoplasia and hyperplasia, and interactive keratinocytes occupy the trigeminal, brachial and lumbosacral dermatomes, zones of high embryonic induction, forming an ectodermal placodal system. Melanin units and hair follicles serve as photoreceptors. Migration of active melanocytes to defined areas is evident in pigment patterns in guinea pigs. This study identifies defined photoreceptor melanocyte/epidermal domains which read the seasonal photophase and control the sleep waking cycle in response to the environmental light. I. Whole skin organ cultures, and epidermal strips from margin of vitiligo in G2 phase are exposed to UV and IR to study sequential and dose response of marginal melanocytes, using histochemistry, immunohistochemistry to assess pigment, biogenic amines and hormones on UV exposure. II. Dermatomic Distributions: Detailed maps of melanocyte photoresponse in 356 biopsies, lesions in 297 vitiligo, 100 melanosis, 165 melanomas 142 leprosy and 442 basal cell/keratinocytes lesions were assessed for patterns of dermatomic distribution. Embryonal melanocyte migration along dermatomes was assessed in 285 guinea pigs from an inbred colony having black, brown and white patches.
色素细胞是迁移至表皮和毛囊的最大一群神经嵴细胞,它们沿着神经褶,沿每个皮节区域迁移。负责光调节的黑视蛋白系统,是从非洲爪蟾(Xenopus laevis)对光有反应的光敏真皮黑素细胞中分离出来的。黑素细胞形成一个光反应网络,以同样的方式读取环境中光周期的季节性变化。本研究旨在通过以下方式研究该系统的组织:一、光反应的实验评估;二、皮肤中有组织的光感受器系统的证据。在G2期白癜风边缘的全皮肤器官培养物和表皮条中的黑素细胞,表现出明显的树突状形态,并在紫外线照射下表达色素、生物胺和激素。光反应取决于光敏酶NAT/HIOMT和多巴氧化酶。黑素细胞与相邻的角质形成细胞以及真皮毛细血管和神经末梢相互作用。黑素细胞网络像松果体一样,通过褪黑素/血清素开关读取昼夜和季节性光相。利用这一机制的光疗可纠正睡眠障碍和冬季抑郁症。表现出光活性、发育不全、发育不良和增生的黑素细胞,以及相互作用的角质形成细胞占据三叉神经、臂部和腰骶部皮节,即胚胎诱导高的区域,形成一个外胚层基板系统。黑色素单位和毛囊充当光感受器。在豚鼠的色素模式中,活跃黑素细胞向特定区域的迁移很明显。本研究确定了特定的光感受器黑素细胞/表皮区域,这些区域读取季节性光相,并根据环境光控制睡眠-觉醒周期。一、将G2期白癜风边缘的全皮肤器官培养物和表皮条暴露于紫外线和红外线,以研究边缘黑素细胞顺序和剂量反应,使用组织化学、免疫组织化学评估紫外线照射下的色素、生物胺和激素。二、皮节分布:对356份活检、297例白癜风病变、100例黑变病、165例黑色素瘤、142例麻风病和442例基底细胞/角质形成细胞病变中黑素细胞光反应的详细图谱进行皮节分布模式评估。在285只来自具有黑色、棕色和白色斑块的近交群体的豚鼠中,评估胚胎黑素细胞沿皮节的迁移情况。