Successful culture of adult human melanocytes obtained from normal and vitiligo donors.

The development of growth conditions for human melanocytes from uninvolved skin from vitiligo patients and age-matched normal adults is a prerequisite to understanding the etiology of this pigmentary disorder. By using new growth conditions, pure melanocyte cultures were prepared from normal adults and the pigmented skin of vitiligo donors. Both cell types grew without a lag period and were maintained for more than six months (4-8 passages). The cultures could be expanded from several thousand melanocytes in the original cell suspension to several million cells (2-7 x 10(6] in pure culture. To obtain these results, the current standard conditions for the culture of fetal melanocytes were substantially modified. MEM-S medium was less satisfactory than MCDB-153. Adult normal and vitiligo cells also required the presence of exogenous catalase (20 micrograms/ml) during isolation and primary seeding. Thereafter, this enzyme was not necessary. Melanocytes grew best and gave the highest yields if the concentrations of both calcium (200 microM) and the phorbol ester 12-0-tetradecanoylphorbol-13-acetate (TPA) were low (4-8 nM). Other growth factors included in the MCDB-153 media were bFGF, crude bovine pituitary extract, insulin, transferrin, hydrocortisone, 5% FCS, and the antioxidant alpha-tocopherol. Cholera toxin and isobutylmethylxanthine (IBMX) were omitted from the MCDB-153 growth medium because they slowed down growth even at very low concentrations. The results indicate adult and vitiligo melanocytes can be cultured. Preliminary studies of the normal and vitiligo cells indicate that vitiligo melanocytes retain some of the ultrastructural abnormalities observed in skin even when grown in culture.     

NB-UVB对白癜风患者黑素细胞生物学特性的影响

目的：明确窄谱中波紫外线(narrow-band UVB, NB-UVB)对白癜风患者的黑素细胞生物学特性的影响。方法：提取34例白癜风患者皮损处黑素细胞进行体外培养。每例样本分组后分别接受不同的照射剂量（0、20、40、60、80、100 mJ/cm2）的NB-UVB处理，照射后1 d采用免疫印迹法对黑素细胞中微管相关蛋白轻链3 II/I(LC3 II/I)、酸化哺乳动物雷帕霉素靶蛋白(p-mTOR)、自噬信号磷酸化磷酸腺苷蛋白激酶(p-AMPK)、P26蛋白的表达情况进行测定。照射后2d、3d、4d采用MTT法对黑素细胞的增殖活性进行测定，采用NaOH染色法对黑素细胞中黑素含量进行测定。结果：随着NB-UVB照射剂量的增加,LC3 II/I和p-AMPK表达水平逐渐上调，p-mTOR和P26的表达水平逐渐下降。不同NB-UVB剂量下，黑素细胞增殖水平增加，但随剂量的增加，增殖的程度逐渐减弱。不同NB-UVB剂量黑素细胞中黑素水平升高，且呈剂量依赖式递增。结论：NB-UVB能够有效调节白癜风患者黑素细胞自噬相关蛋白表达水平，活化自噬信号通路，促进黑素细胞增殖及黑素合成能力。     

Culture of normal adult human melanocytes

Melanocytes isolated from normal adult human skin were cultured in vitro. Separation of the epidermis from the dermis by trypsin flotation proved better than collagenase treatment for providing viable cultures of melanocytes with a minimum of fibroblast contamination. Centrifugation on a discontinuous, rather than a continuous Percoll gradient, was more efficient in separating the epidermal cell types. Most of the melanocytes were usually found in one particular layer, and most of the viable keratinocytes were in the sediment. None of the layers produced a uniformly high percentage of melanocytes on routine culture, but enriched melanocyte cultures could be obtained by seeding the epidermal cells in magnesium- and calcium-free medium for 24 to 48 hours, and then transferring them to fibroblast-conditioned medium containing horse serum and polyamines. Melanocytes were identified by their dendritic morphology, ultrastructure, reaction to cholera toxin and pigment production after treatment with melanocyte stimulating hormone. Pure cultures of melanocytes have been cultivated by this method for more than 43 weeks (ten passages).     

Growth defects of melanocytes in culture from vitiligo subjects are spontaneously corrected in vivo in repigmenting subjects and can be partially corrected by the addition of fibroblast-derived growth factors in vitro

Summary Melanocytes cultured from uninvolved skin of untreated vitiligo subjects have decreased initial seeding capacities, manifest a lag period for the onset of the growth phase, and cannot be passaged. In contrast, melanocytes obtained from uninvolved and perilesional skin of vitiligo subjects actively repigmenting under 8-methoxy psoralen plus sunlight (PUVA) therapy have higher initial seeding capacities, grow faster without a lag period, and can be passaged to more than 12 passages. Extracts of a fetal lung fibroblast cell line (PMR-GF) that promote the growth rates and passage capacities of melanocytes from normal adult donors have been found also to promote the growth rates and passage capacities of melanocytes from the uninvolved skin of vitiligo subjects. Extracts of a fetal lung fibroblast cell line (PMR-GF), however, did not have any further stimulatory effect on the growth of melanocytes obtained from repigmenting vitiligo subjects. Melanocytes cultured from normal and untreated vitiligo subjects grew individually dispersed in the absence of PMR-GF, but tended to grow in clusters in its presence. Melanocytes from the repigmenting vitiligo subjects, however, tended to grow in clusters even in the absence of PMR-GF. These results indicate that the defective in vitro growth characteristics of melanocytes from vitiligo subjects may be related to the pathogenesis of this disease. It is possible that growth factors may be involved in the process of repigmentation in vitiligo subjects.     

Transplantation of melanocytes in vitiligo

Summary We report the results of a study on 100 patients (aged 12–68) with vitiligo, who were treated by transplantation of cultured autologous melanocytes to the depigmented areas, after removal of the epidermis at the recipient site by dermabrasion. The melanocytes were cultured from a 2x3 cm² superficial shave biopsy taken from pigmented buttock skin. After 2–3 weeks in culture, 700–1000 cells per mm² were applied on 60–500 cm² dermabraded areas, and occluded for 1 week. The repigmented portion of the total treated area amounted to 95–100% in 40 patients, 65–94% in 32, 20–64% in 22, and 0–19% in six. It was more difficult to achieve complete pigmentation on the fingers, elbows and knees. In the first few months following the procedure, the treated areas were often hypo- or hyperpigmented, but after 6–8 months they had acquired the same colour as the surrounding skin. No scarring or other side-effects occurred. The donor site had repigmented after 3–6 months in all but two patients, who also showed poor pigmentation in the transplanted areas. At follow-up after 1 and 2 years in 50 and 10 patients, respectively, the repigmented areas remained unchanged. The method is time-consuming, but the results obtained indicate that the procedure can be valuable in motivated patients, when the extent of vitiligo does not exceed 30% of the total body area, and when the areas to be treated are not actively extending.     

Growth inhibition in normal mammalian melanocytes in vitro

Studies on primary cultures of normal adult melanocyies from the ear skin of a black strain of guinea pigs are reported. Melanocytes have a low proliferation rate and tend to form cohesive groups on a glass surface. The cells undergo division while maintaining close contacts with each other whereas DNA synthesis is rare in melanocytes with multiple contacts.     

Study of CCN3 (NOV) and DDR1 in normal melanocytes and vitiligo skin

We have hypothesised that melanocytes disappear in vitiligo because they are weakly attached to the epidermal basal membrane (melanocytorrhagy). In the epidermis, attachment of melanocytes to collagen IV is mediated through DDR1, which is under the control of CCN3. DDR1 genetic variants have been associated with vitiligo in patients of different ethnic origin. In vitro studies have shown that inhibition of CCN3 induces the detachment of melanocytes. We have studied in parallel the expression of CCN3 and DDR1 in lesional and perilesional skin of patients with vitiligo and the impact of the silencing of CCN3 and DDR1 in normal human melanocytes on their behaviour in epidermal reconstructs. Our in vivo study provides evidence of a dysregulation of the DDR1-CCN3 interaction in vitiligo skin as melanocytes remaining in perilesional skin did not express CCN3. Expression of DDR1 was decreased in lesional versus perilesional vitiligo skin in the majority of patients, and the expression of collagen IV was found decreased in all patients. Silencing of CCN3 in melanocytes induced a significant inhibition of cell adhesion to collagen IV whereas melanocytes transduced with shDDR1 still adhered well on collagen IV and did not increase melanocyte loss in epidermal reconstructs as compared with normal melanocytes. Melanocyte detachment was observed but not in all reconstructs using CCN3 silenced melanocytes. Overall, our study confirms that a downregulation of CCN3 is implicated in melanocyte adhesion in part through DDR1. In vitiligo skin, the interaction of CCN3 with other molecules, such as TGFβ and CCN2, needs to be addressed.     

窄谱中波紫外线辐射对白癜风黑素细胞生物学特性的影响

目的：探讨窄谱中波紫外线（NB—UVS）辐射对白癜风不同部位培养的黑素细胞生物学特性的影响，以指导设定NB—UVB最佳治疗间隔时间。方法：体外培养白癜风患者外观正常皮肤、皮损边缘处黑素细胞，倒置显微镜观察NB一[NB辐射对细胞形态的影响，MTT法和NaOH法检测NB—UVB辐射剂量（0-100mJ/cm^2，cm^2）和作用时间（辐射后48h、72h、96h）对细胞增殖和黑素合成的作用。结果：①NBUVB（50-mJ/cm^2）辐射黑素细胞后，细胞肿胀，树突缩短增粗，黏附性下降；②NB—UVB辐射后48h，在实验剂量下可提高细胞的黑素合成能力，辐射剂量≥60mJ／cm^2可抑制白癜风外观正常皮肤黑素细胞增殖，而≥40mJ／cm^2即可对皮损边缘处黑素细胞产生抑制作用；NB—UVB辐射后72h、96h，可促进黑素细胞增殖和黑素合成，对白癜风外观正常皮肤黑素细胞作用更明显，辐射后72h黑素细胞增殖率和黑素含量达到最高点。结论：NB—UVB辐射后72h对白癜风黑素细胞功能的影响最大，可用以指导临床设定NB-UVB照射最佳的治疗间隔时间。     

白癜风表皮黑素细胞超微结构及小眼畸形相关转录因子转录调控研究

目的 研究白癜风黑素细胞超微结构和小眼畸形相关转录因子 （MITF）及其转录调控的酪氨酸酶相关蛋白（TRP）与白癜风临床类型与病程的相关性。方法 选择不同病程的寻常型白癜风（VV）12例和节段型白癜风（SV）8例,分别取白斑区、白斑边缘正常肤色区和远离白斑正常肤色区的表皮片,经组织学确定其表皮的完整性。透射电镜观察10例患者（VV 6例,SV 4例）不同区表皮黑素细胞的超微结构特点。对所有20例远离白斑正常肤色区的表皮片黑素细胞进行培养,应用免疫印迹方法检测 MITF及其转录调控的酪氨酸酶（TYR）、酪氨酸酶相关蛋白1（TYRP1）和酪氨酸酶相关蛋白2（TYRP2）的表达水平。结果 白癜风表皮黑素细胞超微结构病理改变：10例中7例白斑区表皮内未见黑素细胞,1例短病程和2例长病程VV分别可见少量黑素体显著减少或缺失的黑素细胞;白斑边缘正常肤色区,6例VV中,3例病程小于15个月者可见黑素细胞超微结构异常,而4例SV中仅1例异常;远离白斑正常肤色区,10例黑素细胞超微结构均正常。白癜风表皮黑素细胞MITF及其转录调控TRP的表达：VV的MITF表达下调与TYR、TYRP1、TYRP2的表达下调一致;SV存在MITF显著表达下调,而TYR、TYRP1、TYRP2几均正常表达。结论 VV和SV可能存在不同的表皮黑素细胞超微结构病理改变和MITF转录调控机制。     

体外培养节段型白癜风样无色素痣皮损黑素细胞及其临床意义

【摘要】 目的 评价负压吸疱表皮黑素细胞培养对节段型白癜风样无色素痣的辅助诊断价值。方法 收集2019年6月至2020年3月于杭州市第三人民医院皮肤科依据Coupe标准临床诊断的8例节段型白癜风样无色素痣患者,进行伍德灯、反射式共聚焦显微镜（RCM）检查,308 nm准分子激光试验,负压吸疱获取表皮黑素细胞并培养,记录结果。结果 8例患者中,6例皮损伍德灯下可见荧光,4例RCM下可见色素环完整性缺失,5例经308 nm准分子激光照射试验后未见复色反应。8例患者体外培养的皮损黑素细胞硫酸亚铁染色均阳性,经消化离心后沉淀呈黄白色,电镜下黑素细胞胞质内可见Ⅰ~ Ⅲ期黑素小体;皮损对侧同一解剖部位正常皮肤黑素细胞沉淀则呈黑色,电镜下黑素细胞胞质内可见Ⅰ~ Ⅳ期黑素小体。结论 负压吸疱表皮黑素细胞培养有助于诊断节段型白癜风样无色素痣。     

In vitro phototoxicity test using artificial skin with melanocytes

BACKGROUND: Exposure to ultraviolet radiation (UVR) has been shown to induce cutaneous biological changes and phototoxic reactions. OBJECTIVE: This study was designed to evaluate the usefulness of artificial skin (AS) composed of keratinocytes and melanocytes as an in vitro phototoxicity model for topical agents. MATERIALS AND METHODS: AS was manufactured with three-dimensionally cultured keratinocytes and melanocytes on a de-epidermized dermis (DED). The photobiological responses in AS with and without melanocytes were comparatively examined after ultraviolet A (UVA) exposure. Three test chemicals (8-methoxypsoralen, 6-methylcoumarin and tetracycline) were topically applied onto the AS with melanocytes and after UVA irradiation, the released inflammatory cytokines (IL-1alpha, IL-beta and IL-6) were analyzed. RESULTS: AS with melanocytes showed better epidermal structures, stronger resistance to UVA exposure and photobiological responses closer to in vivo human skin. Releases of inflammatory cytokines were well correlated with the increased phototoxicities of test chemicals. Among the measured cytokines, IL-6 could be the most reliable in vitro marker indicative of phototoxic potential, because it showed statistically significant increase only in case of concurrent exposure to chemicals and UVA. CONCLUSION: The AS with melanocytes may be a useful tool especially for examining UV-induced cutaneous changes and a promising in vitro phototoxicity test model for topical agents.     

中药单体芍药甙促进黑素合成的机制研究

目的:确定芍药甙(paeoniflorin)对促进黑素合成的作用.方法:MTT法测定芍药甙对黑素细胞增殖影响,多巴氧化法和NaOH法测定黑素细胞内酪氨酸酶活性和黑素合成, 定量定时RT-PCR和蛋白印迹法测定酪氨酸酶、酪氨酸酶相关蛋白-1 mRNA表达.结果:100 μg/mL芍药甙对细胞的生长有抑制作用;5～10 μg/mL浓度可促进促黑素细胞的增殖;芍药甙增强酪氨酸酶的活性,增加黑素合成;上调TYR,TRP-1 mRNA表达.结论:芍药甙可促进黑素细胞增殖,通过上调酪氨酸酶的活性促进黑素合成.     

黑素细胞体外纯培养及生物学特性鉴定

为了对体外培养的黑素细胞的生物学特性进行鉴定,采用特殊染色法即多巴染色法和脱黑素染色法、免疫组化方法以及透射电镜技术对经含TPA培养液培养的黑素细胞的形态、结构和功能进行观察,确定培养细胞的性质。结果,多巴染色证实黑素细胞的酪氨酸酶功能正常,脱黑素染色从另一侧面证实细胞内的黑素是真正的黑素;用HMSA－1、HMB45、HMSA－5单克隆抗体证实培养的黑素细胞无间变和恶变,保持正常的生物学特性;电镜结果发现黑素细胞内与合成功能有关的细胞器非常丰富,如核糖体、内质网、线粒体和高尔基复合体等,含有不同阶段的黑素小体,黑素小体的分布、输送均正常。结果示体外培养的黑素细胞的结构和功能保持着丰富的生物学特性。     

Selective cultivation of human melanocytes from newborn and adult epidermis

Development of adequate culture systems for the human epidermal melanocyte is critical to further advances in pigment cell biology. We now report selective growth and long-term maintenance of melanocytes derived from both newborn and adult skin specimens. Disaggregated epidermal cell suspensions were plated in a hormone-supplemented medium containing cholera toxin and a hypothalamic extract treated to remove keratinocyte growth-promoting activity. After 3-4 weeks, pure melanocyte populations could be harvested and serially passaged up to 6 times over several months for a total of 10 or more cumulative population doublings in vitro. Electron microscopic studies revealed metabolically active cells with abundant melanosomes in various stages of melanization throughout the culture lifespan. Differences in size and number of melanosomes attributable to race of the tissue donor were readily apparent, and pigment content of melanocytes from both black and Caucasian donors appeared to increase with time in culture. Newborn melanocytes proliferated more rapidly and survived longer than did adult melanocytes, but there were no consistent morphologic differences as a function of donor age. Comparison of growth potential for the 3 major skin-derived cell types in this hormone-supplemented medium revealed striking specificity for melanocytes, with total elimination of keratinocytes over 1-2 weeks, and no fibroblast proliferation whatever in the absence of serum supplementation. This system promises to facilitate in vitro investigation of epidermal melanocytes in normal and diseased human skin.     

Tumour necrosis factors and several interleukins inhibit the growth and modulate the antigen expression of normal human melanocytes in vitro

In the present study the action of various cytokines as regulators of human melanocyte growth and differentiation was examined in vitro. Primary melanocyte cultures were obtained in complete medium free of 12-O-tetradecanoylphorbol-13-acetate or serum. First passage melanocytes were treated with various concentrations of recombinant tumour necrosis factor alpha and beta (rTNF-alpha, rTNF-beta), as well as with various recombinant interleukins (rIL-1a, rIL-1b, rIL-2, rIL-3, rIL-4 and rIL-6) for 6 days in complete medium and for 6 and 12 days in a mitogen-reduced medium variant. The 4-methylumbelliferyl heptanoate fluorometric microassay and Ki-67 staining were used for assessing cell proliferation, and the immunophenotype was evaluated using various monoclonal antibodies. Melanocyte proliferation in complete medium was inhibited by rTNF-alpha (–24%), rTNF-beta (–17%), rIL-1a (–21%), rIL-1b (–18%) and rIL-6 (–29%); in contrast, rIL-2, rIL-3 and rIL-4 had no antiproliferative effect. Measurements of Ki-67-positive nuclei confirmed these results. In the reduced medium variant, none of the above cytokines inhibited melanocyte proliferation. Recombinant TNF-alpha and rTNF-beta markedly reduced the expression of the pigment cell-associated antigens HMB-45 and K.1.2, and they enhanced the expression of VLA-2, ICAM-1 and HLA class I antigens and strongly induced HLA-DR. Similar changes were induced by rIL-1a, rIL-b and rIL-6, and rIL-2 decreased the expression of HLA class I antigens and of ICAM-1. In conclusion, several cytokines inhibited the growth and modulated the phenotype of melanocytes in vitro. Since these cytokines are major mediators of inflammatory processes, they may cause the pigmentary alterations seen after cutaneous inflammatory processes.Presented in part at the 23rd meeting of the European Society for Dermatological Research (ESDR). Amsterdam, 3–6 April 1992     

角质形成细胞与黑素细胞体外构建含黑素的组织工程皮肤

目的 探讨体外构建含黑素的组织工程皮肤.方法 采用两步酶消化法处理健康小儿包皮,获得表皮细胞悬液,分别用人角质形成细胞(KC)无血清培养基(SFM)及改良的M254黑素细胞培养基培养KC、黑素细胞(MC),并传至第3代.将第3代KC接种于培养瓶中,48 h后加入第3代MC(MC:KC为1:10)混合培养.制备人去表皮的真皮(DED),将培养第3代的MC、KC制成细胞悬液,按照1:10的比例接种于DED表面,采用液下培养和空气-液面培养相结合的方式进行培养,2周后取培养的组织工程皮肤分别做HE染色、角蛋白免疫组化染色及Masson-Fontana染色.结果 KC、MC混合培养于培养皿5 d后,于倒置显微镜下观察到KC呈铺路石状生长,其间散布MC,且树突延伸到KC细胞间.两种细胞混合接种于DED 15 d后,HE染色显示在DED上有3～6层表皮细胞,并可见角质层,角蛋白免疫组化染色阳性,银氨染色显示基底层见黑素着色.结论 MC、KC混合接种于培养皿可构建MC和KC接触生长的单细胞层,将MC、KC接种于DED可构建含有黑素成分的组织工程皮肤.

Abstract：

Objective To construct tissue-engineered skin containing melanin with mixed culture of human keratinocytes (KCs) and melanocytes (MCs) on de-epidermized dermis (DED) in vitro. Methods Single-cell suspension was obtained by digestion of isolated preputial epidermis with pancreatin. Keratinocyte serum-free medium (K-SFM) and modified M254 culture medium were used to culture KCs and MCs respectively. Third-passage KCs were seeded into cell culture flasks and cultured for 48 hours; then, third-passage MCs were seeded into the same cell culture flasks with the MC/KC ratio being 1: 10 followed by a 5-day coculture. The suspension of third-passage KCs and MCs with the MC/KC ratio of 10:1 were seeded onto the surface of a prepared DED and maintained at the air-liquid interface for 11 days following a 4-day submerged culture.Subsequently, the constructed tissue-engineered skin was examined with HE staining, immunohistochemical staining for keratin and Masson-Fontana staining. Results After coculture in flasks for 5 days, KCs exhibited a typical paving-stone appearance, MCs with projected dendrites were scattered in the extracellular space between KCs. HE staining revealed 3 to 6 layers of cells with the formation of stratum corneum after mixed culture on DED for 15 days. Keratin protein was positive throughout the artificial epidermis, and melanin pigments were located in the basal layer of the epidermis as Masson-Fontana staining showed. Conclusions The co-culture of MCs and KCs can form single-cell layers with the contact between MCs and KCs in flasks, and construct tissue-engineered skin with melanin component on DED in vitro.     

Effects of oxygen tension on the growth and pigmentation of normal human melanocytes

The effects of oxygen tension on human melanocyte growth, tyrosinase activity, and melanin production were assessed. Melanocytes, seeded at 10(4) cells/cm2, were grown in modified Eagle's medium (MEM) with 5% fetal bovine serum (FBS) and 10 ng/ml 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Flasks were equilibrated with gas mixtures containing 5% CO2 and various partial pressures of oxygen (PO2 7-620 mm Hg) and kept in incubators, which were electronically maintained at the desired oxygen tensions. Melanocytes grew best at PO2 from 6-34 mm Hg. Growth was reduced by 30% at PO2 142 mm Hg, and even more at O2 tensions greater than 230 mm Hg. A PO2 of 603 mm Hg was cytotoxic. Tyrosinase activity (assayed by the method of Pomerantz) was 300 microU/mg protein at PO2 7-34 mm Hg. At PO2 235 and 355 mm Hg tyrosinase activity decreased to about 100 microU/mg protein. The apparent Km for tyrosine was unchanged in melanocytes cultured at all experimental oxygen tensions. The Vmax, however, was decreased at the higher oxygen tensions (PO2 235 mm Hg). At PO2 6-135 mm Hg the melanin content was proportional to tyrosinase activity. At cytostatic oxygen tensions (PO2 235 and 355 mm Hg) the intracellular melanin content increased somewhat, although tyrosinase activity was decreased. Low oxygen tension is favorable for both melanocyte proliferation and tyrosinase activity.