黑素生成素对黑素细胞增殖和黑素合成作用的研究

古巴学者Ｃａｏ报道胎盘中提取的黑素生成素临床治疗白癜风有效。为了探讨治疗机理，我们按Ｃａｏ法提取黑素生成素，用体外细胞培养方法，在黑素细胞培养中分别加入黑素生成素和胎盘肽，以不加黑素生成素的黑素细胞培养作为对照，用ＭＴＴ法测定细胞增殖情况；用Ｏｉｋａｗａ法测定黑素合成量；用透射电镜观察黑素小体的生成。结果表明，加黑素生成素后，黑素细胞促增殖率为４２．５％，加胎盘肽促增率为５．９％，二者有显著性差异     

外用黑素生成素治疗肢端型白癜风疗效观察

目的研究黑素生成素治疗肢端型白癜风的疗效。方法 21例符合要求的肢端型白癜风患者进入该前瞻性研究。赠送给患者黑素生成素药液和红外线灯等材料。嘱患者2次/d使用红外线灯照射皮损区域,20min/次,照射期间每5min在皮损处涂黑素生成素1次。结果进入研究的患者完成了为期6个月的跟踪治疗。其中显效4例（19.0%）,好转3例（14.3%）,有效率为33.3%。经过数据分析,我们发现年龄较小的患者对该治疗措施的反应较好;足部的治疗效果好于手部。结论外用黑素生成素辅以红外线灯照射治疗安全、有效,可以作为肢端型白癜风,尤其少年儿童肢端型白癜风的重要备择治疗手段。     

与表皮黑素细胞增殖和黑素生成有关的信号转导

本文简要介绍了与黑素细胞增殖和黑素生成有关4条信号转导途径,如二脂酰甘油/蛋白激酶C(DAG/PKC)途径,一氧化氮/环磷酸鸟苷/蛋白激酶G(NO/cGMP/PKG)途径,丝裂原激活的蛋白激酶(MAPK)级联途径和环磷酸腺苷/蛋白激酶A(cAMP/PKA)途径。随着对信号依赖性黑素细胞增殖动力学和黑素代谢的研究将有助于阐明色素障碍性皮肤病的发病机制。同时针对信号转导环节而设计的增(减)色素性药物对色素障碍性皮肤病的临床治疗有着极其广阔的前景。     

负压吸疱自体表皮移植加黑素生成素治疗白癜风

负压吸疱自体表皮移植治疗稳定期的白癜风，自１９７１年Ｆａｌａｂｅｌａ［１］报告以后，目前已在国内广泛开展、文献报告成活率在４３．３％～９１％不等，我科在移植３００余例，移植表皮片１２００片以上的基础上，对其中５例经多次移植失败的患者（非表皮片１周内脱...     

黑素生成素对黑素瘤mel586细胞白癜风相关基因-1和酪氨酸酶表达的影响

采用MTT法测定黑素生成素对细胞增殖率的影响;多巴氧化法测定酪氨酸酶活性;半定量RT-PCR检测黑素生成素对黑素细胞白癜风相关基因-1（VIT-1）,酪氨酸酶（TYR）和酪氨酸酶相关蛋白-1（TRP1）基因表达的影响。结果：黑素生成素能促进黑素瘤细胞mel586的增殖,并与浓度呈正相关性,对TYR和TRP-1mRNA表达无明显促进作用;黑素生成素在浓度为6μg/mL和12μg/mL时对黑素瘤细胞mel586酪氨酸酶活性有促进作用（P〈0.05）。黑素生成素治疗白癜风有效的机制可能与提高VIT-1的表达量和促进细胞增殖有关。     

长波紫外线照射对培养的正常人黑素细胞增殖及黑素合成的影响

目的 了解UVA对黑素细胞增殖及黑素合成的影响.方法 采用体外细胞培养技术、MTT法及NaOH法研究不同剂量UVA照射对黑素细胞增殖和黑素合成的作用.结果 随着照射时间的增加,黑素细胞的增殖率增加,黑素合成量也增加.结论 照射剂量在3.6J/cm²以内时,黑素细胞增殖率逐步上升,以后趋向稳定.在测定的照射剂量内,黑素合成量与照射剂量呈正相关.     

甲氧沙林对人毛囊黑素细胞增殖、活化和黑素合成作用的研究

目的 研究甲氧沙林对人毛囊黑素细胞活化、增殖和黑素合成的影响.方法 体外培养正常人毛囊黑素细胞,观察不同浓度甲氧沙林(10～500μmol/L)对毛囊黑素细胞形态、增殖、酪氨酸酶活性和黑素合成的影响.结果 50μmol/L甲氧沙林处理细胞7d后,毛囊黑素细胞树突明显增多延长,胞浆内出现较多棕褐色颗粒,酪氨酸酶活性和黑素含量增加显着高于对照组(P<0.01).结论 甲氧沙林能诱导毛囊黑素细胞树突增多延长,酪氨酸酶活性和黑素含量增加.     

p21小干扰RNA对低浓度过氧化氢诱导的黑素细胞提前衰老和黑素传递的影响

目的:探讨小干扰RNA(siRNA)抑制p21表达对低浓度过氧化氢(H₂O₂)诱导的黑素细胞提前衰老的影响,以及黑素细胞提前衰老与黑素传递功能间的关系。方法:p21 siRNA序列转染黑素细胞,采用荧光显微镜、实时荧光定量聚合酶链式反应(qRT-PCR)及western blot检测抑制效率。将正常人黑素细胞分为对照组(阴性siRNA转染处理)、p21 siRNA组(p21 siRNA转染处理)、阴性siRNA+H₂O₂组(阴性siRNA转染24 h后加入400μmol/L H₂O₂处理)及p21 siRNA+H₂O₂组(p21 siRNA转染24 h后加入400μmol/L H₂O₂处理)。采用β-半乳糖苷酶染色检测细胞衰老;EdU细胞增殖检测细胞增殖能力;western blot检测各组p21和树突调节蛋白[RhoA、Rac1及细胞分裂周期蛋白42(Cdc42)]表...     

黄芩甙对紫外线诱导人正常黑素细胞黑素合成的抑制作用研究

体外培养黑素细胞（MC）分别经隔日长波紫外线（UVA）或中波紫外线（UVB）照射和（或）黄芩处理后，观察细胞增殖情况，测定酪氨酸酶活性和黑素含量。结果：（1）UVA使细胞增殖增快，但剂量较大时增殖减发电量；UVB使细胞增殖减慢。二者均可使细胞酪氨酸酶活性和黑素含量高于对照组。（2）黄芩具有抑制UVA和UVB诱导的MC增殖、酪氨酸酶活性及黑素合成改变的作用。提示黄芩能抑制UVA和UVB诱导的细胞反应，还可通过抑制酪氨酸酶减少MC黑素合成。     

含中药血清对体外黑素细胞增殖及黑素合成量的影响

目的　探讨含中药白净冲剂血清对黑素细胞 (MC)增殖及合成黑素功能的影响。方法　体外培养人MC,于对数生长期加 10%浓度的大鼠含中药白净冲剂血清培养 56h后,分别采用噻唑蓝法(MTT法)和NaOH法检测MC增殖及合成黑素的情况,并与大鼠转移因子注射后含药血清组作对照。空白对照大鼠血清为空白对照组。结果　中药白净冲剂及转移因子含药血清组对MC增殖较空白对照组有明显促增殖作用,合成黑素量显著增加,差异均有显著性 (P均<0. 01)。结论　含中药白净冲剂血清有促进MC增殖作用,并使MC合成黑素增加。     

Trypsin induces epidermal proliferation and inflammation in murine skin

Human keratinocytes are known to express the protease-activated receptors, PAR-1 and PAR-2. Activation of PAR-1 results in increased proliferation, whereas PAR-2 activation results in decreased keratinocyte proliferation. Trypsin activates PAR-1 and in higher concentrations, PAR-2. The aim of this study was to evaluate the overall effect of trypsin on keratinocyte proliferation in a mouse in vivo and in vitro model. Daily topical application of 0.3-300 pmol trypsin/cm2 on hairless mouse skin induced dose-dependent epidermal hyperproliferation as determined by an increase in 5-bromo-2'-deoxyuridine incorporation of up to eight-fold in basal keratinocytes and an up to three-fold increase in keratinocyte layers. This was accompanied by an increased transepidermal water loss. These effects of trypsin were abolished by the addition of the trypsin inhibitor n-p-tosyl-l-lysine-chloromethyl ketone. Histological analysis revealed acanthosis, hypergranulosis, and spongiosis in the epidermis as well as vasodilatation and an inflammatory infiltrate in the upper dermis. In the murine keratinocyte cell line PAM-212 activation of PAR-1 with specific activating peptides resulted in a calcium influx and an increase of proliferation, whereas activation of PAR-2 caused a diminished proliferation. Incubation with trypsin, PAR-1-, and PAR-2-activating peptides induced cytokine-induced neutrophil chemoattractant (KC) mRNA expression as a marker for inflammation in PAM-212 in a dose-dependent manner. In conclusion, our results suggest that trypsin induces in vivo epidermal proliferation and inflammation. Proliferation seems not to be signaled by PAR activation, but PAR-2-induced KC chemokine expression may contribute in part to trypsin-induced inflammation.     

Low-energy helium-neon laser induces locomotion of the immature melanoblasts and promotes melanogenesis of the more differentiated melanoblasts: recapitulation of vitiligo repigmentation in vitro

Helium-neon laser (He-Ne Laser, 632.8 nm) is a low-energy laser that has therapeutic efficacy on various clinical conditions. Our previous study has demonstrated efficacy of He-Ne laser on vitiligo, a disease characterized by skin depigmentation. To regain skin tone on vitiligo lesions, the process began by the migration of the immature melanoblasts (MBs) to the epidermis, which was followed by their functional development to produce melanin. In this study, we investigated the physiologic effects of He-Ne laser irradiation on two MB cell lines: the immature NCCmelb4 and the more differentiated NCCmelan5. The intricate interactions between MBs with their innate extracelluar matrix, fibronectin, were also addressed. Our results showed that He-Ne laser irradiation enhanced NCCmelb4 mobility via enhanced phosphorylated focal adhesion kinase expression and promoted melanogenesis in NCCmelan5. In addition, He-Ne laser decreased the affinity between NCCmelb4 and fibronectin, whereas the attachment of NCCmelan5 to fibronectin increased. The alpha5beta1 integrin expression on NCCmelb4 cells was enhanced by He-Ne laser. In conclusion, we have demonstrated that He-Ne laser induced different physiologic changes on MBs at different maturation stages and recapitulated the early events during vitiligo repigmentation process brought upon by He-Ne laser in vitro.     

Fibroblast growth factor 10 induces proliferation and differentiation of human primary cultured keratinocytes

Fibroblast growth factor 10 is a novel member of the fibroblast growth factor family, which is involved in morphogenesis and epithelial proliferation. It is highly homologous to the keratinocyte growth factor (or fibroblast growth factor 7), a key mediator of keratinocyte growth and differentiation. Both fibroblast growth factor 10 and keratinocyte growth factor bind with high affinity to the tyrosine kinase keratinocyte growth factor receptor. Here we analyzed the effect of fibroblast growth factor 10 on primary cultures of human keratinocytes, grown in chemically defined medium, and we compared the proliferative and differentiative cell responses to fibroblast growth factor 10 with those induced by keratinocyte growth factor and epidermal growth factor. Cell counting, 5-bromo-2'-deoxyuridine incorporation, and western blot analysis showed that fibroblast growth factor 10, similarly to keratinocyte growth factor, not only is a potent mitogen for human keratinocytes, but also promotes the expression of both early differentiation markers K1 and K10 and late differentiation marker filaggrin in response to the Ca2+ signal, and seems to sustain the proliferative activity in suprabasal stratified cells. Immunoprecipitation/western blot analysis revealed that fibroblast growth factor 10, similarly to keratinocyte growth factor, is able to induce tyrosine phosphorylation of keratinocyte growth factor receptor and of cellular substrates such as PLCgamma.     

sprouty4蛋白对角质形成细胞增殖及分化的影响

 目的:探证sprouty4(SPRY4)蛋白对角质形成细胞增殖及分化的影响。方法：以人永生化表皮细胞株HaCaT细胞作为实验对象,实验组HaCaT细胞采用基因敲降技术进行SPRY4蛋白抑制物的转染,对照组HaCaT细胞不作任何处理。运用实时荧光定量PCR技术（RT-qPCR）检测实验组与对照组中sprouty4蛋白对HaCaT细胞分化指标Involucrin、CK1与CK10的影响,运用CCK-8实验检测HaCaT细胞的增殖功能。结果：RT-qPCR结果显示,实验组HaCaT细胞中SPRY4基因敲降成功,敲降率约为94.75%。与对照组相比,实验组HaCaT细胞中分化指标Involucrin、CK1与CK10表达水平降低;CCK-8实验结果显示,与对照组相比,实验组HaCaT细胞增殖能力增强。结论：SPRY4蛋白表达下降对细胞增殖起到促进作用,对细胞分化起到抑制作用。     

Effects of cepharanthine and minoxidil on proliferation,differentiation and keratinization of cultured cells from the murine hair apparatus

Summary The effects of cepharanthine and minoxidil on proliferation, differentiation and keratinization of cultured cells from the murine hair apparatus were examined electron microscopically. Both cepharanthine and minoxidil stimulated cell proliferation and delayed initiation of differentiation and keratinization of the cultured cells. On day 6, most control cells (87%) cultured in a 0.03 mM calcium medium without cepharanthine and minoxidil were differentiated into several subpopulations corresponding to those of in vivo cell layers of the hair apparatus, while most of the cells cultured with cepharanthine (71%) or minoxidil (70%) were still immature. On day 13, the number of degenerated cells increased (63%) in the control culture, whereas in the culture treated with cepharanthine or minoxidil, cell degeneration scarcely occurred (5% and 8%, respectively). Differentiated cells having tonofilaments were often observed in the cepharanthine- and minoxidil-treated cultures (76% and 72%, respectively). Elevation of extracellular calcium up to 1.0 mM induced keratinization (34%) in the control culture on day 6, while no keratinized cells were observed in the cepharanthine- or minoxidil-treated culture. On day 13 keratinization similarly occurred in the cultures with cepharanthine (30%) or minoxidil (48%). These results show that both cepharanthine and minoxidil may directly influence proliferation, differentiation and keratinization of cultured cells from the hair apparatus.     

The role of the TRAF-interacting protein in proliferation and differentiation

Ubiquitination of proteins is a post-translational modification, which decides on the cellular fate of the protein. Addition of ubiquitin moieties to proteins is carried out by the sequential action of three enzymes: E1, ubiquitin-activating enzyme; E2, ubiquitin-conjugating enzyme; and E3, ubiquitin ligase. The TRAF-interacting protein (TRAIP, TRIP, RNF206) functions as Really Interesting New Gene (RING)-type E3 ubiquitin ligase, but its physiological substrates are not yet known. TRAIP was reported to interact with TRAF [tumor necrosis factor (TNF) receptor-associated factors] and the two tumor suppressors CYLD and Syk (spleen tyrosine kinase). Ectopically expressed TRAIP was shown to inhibit nuclear factor-kappa B (NF-κB) signalling. However, recent results suggested a role for TRAIP in biological processes other than NF-κB regulation. Knock-down of TRAIP in human epidermal keratinocytes repressed cellular proliferation and induced a block in the G1/S phase of the cell cycle without affecting NF-κB signalling. TRAIP is necessary for embryonal development as mutations affecting the Drosophila homologue of TRAIP are maternal effect-lethal mutants, and TRAIP knock-out mice die in utero because of aberrant regulation of cell proliferation and apoptosis. These findings underline the tight link between TRAIP and cell proliferation. In this review, we summarize the data on TRAIP and put them into a larger perspective regarding the role of TRAIP in the control of tissue homeostasis.     

Depilatory chemical thioglycolate affects hair cuticle and cortex,degrades epidermal cornified envelopes and induces proliferation and differentiation responses in keratinocytes

Thioglycolate is a potent depilatory agent. In addition, it has been proposed to be useful as a penetration enhancer for transepidermal drug delivery. However, the effects on hair structure and stress responses it elicits in epidermal keratinocytes have not been fully characterised. We have used label‐free confocal and fluorescence lifetime imaging supported by electron microscopy to demonstrate how thioglycolate damages hair cuticle cells by generating breakages along the endocuticle and leading to swelling of cortex cells. Maleimide staining of free SH‐groups and a decrease in the average fluorescence lifetime of endogenous fluorophores demonstrate a specific change in protein structure in both hair cuticle and cortex. We found that the thioglycolate damages cornified envelopes isolated from the stratum corneum of the epidermis. However, thioglycolate‐treated epidermal equivalent cultures recover within 48 hours, which highlights the reversibility of the damage. HaCaT keratinocytes respond to thioglycolate by increased proliferation, onset of differentiation and expression of the chaperone protein Hsp 70, but not Hsp 27. Up‐regulation of involucrin can be blocked by an application of c‐Jun N–terminal kinase (JNK) inhibitor, but the up‐regulation of Hsp 70 takes place regardless of the presence of the JNK inhibitor.