紫外线照射后生成的微囊泡对成纤维细胞氧化损伤及凋亡的作用

目的：明确对UVA及UVB照射后皮肤成纤维细胞生成的微囊泡对成纤维细胞氧化损伤及凋亡的作用。方法：紫外线照射人皮肤成纤维细胞,提取细胞上清液中的微囊泡,利用光散射分析技术鉴定分析微囊泡的大小及数量。将紫外线照射后生成的微囊泡与正常成纤维细胞共孵育,荧光酶标仪定量检测活性氧含量,流式细胞仪检测细胞凋亡率。结果：UVA及UVB照射后皮肤成纤维细胞释放的微囊泡数量及大小明显高于正常成纤维细胞释放的微囊泡。正常纤维细胞、UVA和UVB照射后的成纤维细胞与微囊泡共孵育后活性氧荧光值分别为（52.76±1.4347）、（82.60±4.082）和（85.94±6.264）,凋亡率分别为（3.260±1.732）%,（28.94±2.430）%和（34.48±2.718）%,细胞的氧化损伤和凋亡可被抗氧化剂逆转。结论：急性中长波紫外线照射可诱导皮肤成纤维细胞释放微囊泡进一步介导细胞的氧化损伤和凋亡。     

中波紫外线诱导人皮肤成纤维细胞自噬对凋亡影响的初步研究

[目的]探讨不同剂量中波紫外线(UVB)照射人皮肤成纤维细胞诱导的自噬对细胞凋亡活性的影响.[方法]人皮肤成纤维细胞来自于23岁健康男性环切术后包皮的原代培养,连续传代培养后取第3～ 10代的细胞进行实验.通过单丹酰戊二胺(MDC)染色和免疫荧光标记微管相关蛋白1轻链3(LC3)的方法,确定不同剂量3-甲基腺嘌呤(3-MA)对自噬的抑制作用.UVB照射后立即加入0.5 mmol/L 3-MA孵育细胞4h作为自噬的抑制方法.Hoechst和碘化丙啶(PI)染色结合Annexin V-异硫氰酸荧光索(FITC)和PI标记细胞后流式细胞仪检测作为细胞凋亡的定性和定量方法.[结果]0.5 mmol/L 3-MA能明显抑制人皮肤成纤维细胞自噬活性(饥饿诱导组自噬细胞阳性百分数为63.037％±5.876％,3-MA孵育后下降至34.425％±5.183％).空白对照组、30、50、100mJ/cm2UVB照射组标记LC3绿色荧光信号逐渐增强,照射后立即对上述4组加入3-MA孵育4h则LC3蛋白表达差异不明显.0.5 mmol/L 3-MA对细胞活性影响最小.50 mJ/cm2 UVB照射下加入3-MA孵育较未加3-MA孵育细胞强Hoechst和强PI双染细胞增多;100 mJ/cm2 UVB照射后加3-MA孵育较未加3-MA孵育细胞强Hoechst和强PI双染细胞减少.Annexin V -FITC和PI标记细胞后流式细胞仪分析显示,在50 mJ/cm2 UVB照射下,抑制自噬的细胞中晚期凋亡水平[( 10.933±0.839)％]较未抑制细胞[(7.267±0.473)％]上升,两者之间差异具有统计学意义(t=5.20,P＜ 0.05);而在100mJ/cm2UVB照射下,抑制自噬的细胞中晚期凋亡水平[(7.100±0.781)％]较未抑制细胞[( 10.133±0.681)％]下降,两者之间差异具有统计学意义(t=6.29,P＜ 0.05).[结论]50 mJ/cm2 UVB照射诱导人皮肤成纤维细胞自噬通过抑制凋亡对细胞起到保护作用,而在100 mJ/cm2 UVB照射下发生的较高水平自噬可能诱导了自噬性细胞死亡.     

白藜芦醇对UVB照射的人皮肤成纤维细胞MMP-1水平及细胞凋亡的影响

目的初步探寻红葡萄酒中主要活性成分白藜芦醇对紫外线照射皮肤保护作用的可能机制。方法白藜芦醇对UVB照射的人皮肤成纤维细胞基质金属蛋白酶(MMP)-1水平及细胞凋亡的影响。将培养的人皮肤成纤维细胞分为5组,A组:无UVB照射无干预组,B组:UVB照射无干预组,C组:UVB照射1μmol/L白藜芦醇干预组,D组:UVB照射10μmol/L白藜芦醇干预组,E组:UVB照射100μmol/L白藜芦醇干预组。UVB照射剂量均为30mJ/cm2。用免疫组织化学方法分别检测5组细胞中MMP-1水平,用磷脂酰丝氨酸外翻分析(AnnexinV法)检测细胞凋亡率。结果 A～E组5组细胞MMP-1阳性细胞评分及凋亡率差异均有统计学意义(P均<0.05)。A组评分及凋亡率均明显低于B组,两组比较差异有统计学意义(P均<0.05),B组与C,D,E组评分及凋亡率比较差异均有统计学意义(P均<0.05),C～E组3组评分及凋亡率比较差异亦有统计学意义(P<0.05)。结论白藜芦醇可以抑制UVB照射诱导的人皮肤成纤维细胞MMP-1水平的升高,并可减少细胞因UVB照射引起的凋亡,白藜芦醇可能通过此机制对紫外线照射皮肤起到保护作用。     

咖啡因可保护UVB致人皮肤成纤维细胞的损伤

目的：确定咖啡因对中波紫外线（UVB）照射致体外培养人皮肤成纤维细胞氧化损伤的防护作用.方法：分离培养人成纤维细胞,分为空白对照组、咖啡因组、UVB照射组、UVB照射＋咖啡因组,UVB照射剂量为30 mJ/cm2.用MTT法检测细胞增殖活性,酶生化比色法检测细胞丙二醛（MDA）含量、超氧化物歧化酶（SOD）及谷胱甘肽过氧化物酶（GSH-Px）活性.结果：UVB照射前后用咖啡因处理能使成纤维细胞存活率提高、MDA产生减少,酶的活性增强.结论：咖啡因对UVB照射损伤成纤维细胞具有一定保护性作用,其机制可能与抑制氧化损伤和增强抗氧化能力有关.     

UVB诱导人皮肤成纤维细胞的氧化应激损伤研究

目的 观察人皮肤成纤维细胞被UVB照射后的光损伤、凋亡、周期阻滞和氧化应激损伤状态,并检测氧化应激的相关信号蛋白p66Shc的表达情况。方法 用小剂量UVB多次照射培养的人皮肤成纤维细胞,以细胞衰老β-半乳糖苷酶（SA-β-Gal）化学染色法观察细胞衰老状态,流式细胞仪检测细胞凋亡和细胞周期,ELISA法检测细胞内超氧化物歧化酶活性和丙二醛的含量,并以Western印迹法检测p66Shc蛋白的表达。结果 SA-β-Gal染色显示,培养的人皮肤成纤维细胞在UVB照射后呈强阳性染色;细胞凋亡率在未照射的对照组为0.96％,UVB照射组为37％;而细胞周期检测显示,经UVB照射的人皮肤成纤维细胞大部分阻滞于G0/G1期（80.07%）。细胞内超氧化物歧化酶水平对照组为（52.35 ± 4.97） ng/g蛋白,UVB照射组为（7.81 ± 0.68） ng/g蛋白（两组比较,P < 0.01）;而丙二醛水平两组分别为（3.52 ± 0.34） ng/g蛋白和（33.91 ± 3.20） ng/g蛋白（两组比较,P < 0.05）。人皮肤成纤维细胞经UVB照射诱导后24 h,p66Shc呈弱阳性表达,48 h后表达进一步增强。结论 培养的人皮肤成纤维细胞经UVB照射后进入氧化应激增强状态。p66Shc蛋白在此过程中表达逐渐增强。     

UVB对皮肤成纤维细胞相关骨架蛋白表达的影响

目的:确定UVB对皮肤成纤维细胞骨架蛋白的影响.方法:用150 mJ/cm2的UVB照射培养的皮肤成纤维细胞,用MTT法检测细胞活性,用Western blot法检测α-微管蛋白、β-微管蛋白、β-肌动蛋白和波形蛋白的含量.结果:150 mJ/cm2 UVB照射后β-微管蛋白含量逐渐降低,波形蛋白逐渐升高,α-微管蛋白和β-肌动蛋白改变不明显.结论:在UVB诱导人皮肤成纤维细胞光损伤过程中,β-微管蛋白和波形蛋白可能发挥着重要作用.     

红景天甙对UVA/UVB辐射的成纤维细胞中caspase-3和caspase-8活性的影响

目的:测定经UVA/UVB辐射的体外培养人皮肤成纤维细胞半胱氨酸天冬氨酸蛋白酶-3(caspase -3)和半胱氨酸天冬氨酸蛋白酶-8(caspase-8)活性,观察红景天甙对细胞凋亡信号传导过程中caspase通路的干预作用.方法:在进行UVA/UVB辐射的体外培养人皮肤成纤维细胞实验组中加入红景天甙,应用比色法检测caspase -3和caspase -8活性.结果:UVA/UVB辐射体外培养的成纤维细胞后,caspase -3和caspase -8活性均增高;加入红景天甙后,caspase -3和caspase -8活性均降低.结论:红景天甙可以降低caspase -3和caspase -8的活性,延缓成纤维细胞的凋亡过程.     

UVB照射对皮肤成纤维细胞产生受体相互作用蛋白-1的影响

目的:评价UVB照射对培养皮肤成纤维细胞受体相互作用蛋白-1(RIP-1)的影响.方法:采用150 mJ/cm2 UVB照射体外培养的人皮肤成纤维细胞,照射后12、24、36和48 h,MTT法检测细胞活性,RT-PCR法检测细胞中RIP-1 mRNA的变化,Western blot检测RIP-1蛋白水平.结果: UVB照射后,细胞活性进行性下降,RIP-1 mRNA逐渐减少,RIP-1蛋白含量逐渐升高.结论: 在UVB引起的皮肤成纤维细胞急性损伤过程中,RIP-1可能发挥着重要作用.     

Akt/mTOR活化抗UVB诱导HaCaT细胞凋亡的研究

目的 探讨Akt/mTOR信号通路活化抗中波紫外线（UVB）诱导的HaCaT细胞凋亡。方法 UVB照射角质形成细胞,Western印迹检测Akt/mTOR通路中相关信号分子的动态水平变化。免疫荧光 Hoechst 33342染色观察HaCaT细胞凋亡率。结果 UVB能活化Akt/mTOR信号通路,并在一定范围内（5 ～ 30 mJ/cm2）成剂量依赖性,在一定范围内（5 ～ 30 min）成时间依赖性。EGFR抑制剂PD 153035、PI3K抑制剂LY 294002和mTOR抑制剂雷帕霉素能显著抑制UVB对Akt/mTOR信号通路的活化作用。UVB照射前加入雷帕霉素、LY 294002预处理,HaCaT细胞凋亡率增加。结论 Akt/mTOR活化抗UVB诱导的HaCaT细胞凋亡。     

Nrf2信号通路调控自噬对UVA诱导人真皮成纤维细胞凋亡的作用

目的 探讨Nrf2信号通路介导的细胞自噬在UVA诱导人皮肤成纤维细胞凋亡过程中的作用。方法 体外培养正常人皮肤成纤维细胞，分为对照组、UVA组、自噬诱导剂雷帕霉素(rapamycin, RAPA)组、自噬抑制3-甲基嘌呤(3-methyladenine, 3-MA)组、核因子E2相关因子2(Nrf2)抑制剂(ML385)组及干涉(siRNA)组；各实验组经8 J/cm²的UVA照射；采用流式细胞术检测成纤维细胞凋亡；CCK-8检测细胞活性变化；Western blot检测细胞自噬及凋亡关键分子、p62及Nrf2蛋白表达水平。结果 经8 J/cm²的UVA照射后成纤维细胞凋亡比例增加、胞内自噬水平显著升高；自噬抑制剂3-MA处理后可显著促进UVA照射引起的成纤维细胞凋亡；而自噬促进剂RAPA处理细胞后，细胞凋亡率较UVA组相比显著降低(P<0.01);与对照组相比，UVA照射后胞核Nrf2表达显著增高；ML385阻断Nrf2入核及使用siRNA干涉Nrf2表达后，自噬关键蛋白LC3Ⅱ/Ⅰ降低(P<0.01),p62表达显著减少(P&...     

Baicalein inhibits matrix metalloproteinase 1 expression via activation of TRPV1‐Ca‐ERK pathway in ultraviolet B–irradiated human dermal fibroblasts

Increased matrix metalloproteinase 1 (MMP‐1) expression is a feature of photo‐aged skin. We investigated the effects of baicalein and sulphoraphane on ultraviolet B (UVB) irradiation–induced MMP‐1 expression and apoptosis using human dermal fibroblasts. UVB irradiation not only increased MMP‐1 expression, but also caused apoptosis. Both baicalein and sulphoraphane protected cells from UVB irradiation–induced apoptosis, but only baicalein inhibited MMP‐1 expression. UVB irradiation activated 12‐lipoxygenase, and its product, 12‐hydroxyeicosatetraenoic acid, activated TRPV1 channels. The resulting UVB irradiation–induced Ca²⁺ increase was blocked by the 12‐lipoxygenase inhibitor baicalein and the TRPV1 blocker capsazepine, but not by the Nrf2 inducer sulphoraphane. UVB irradiation also increased ROS generation and decreased Nrf2 protein levels. UVB irradiation–induced MMP‐1 expression was blocked by the Ca²⁺ chelator BAPTA, by capsazepine and by TRPV1 silencing. However, induction was unaffected by the antioxidant N‐acetylcysteine. ERK phosphorylation and JNK phosphorylation were induced by UVB irradiation, but only ERK phosphorylation was Ca²⁺ sensitive. Increased MMP‐1 expression was blocked by PD98059, but not by SP600125. Thus, increased MMP‐1 expression is mediated by increased cytosolic Ca²⁺ and ERK phosphorylation. UVB irradiation–induced ROS generation is also Ca²⁺ sensitive, and UVB irradiation–induced apoptosis is caused by increased ROS. Thus, baicalein, by blocking the UVB irradiation–induced cytosolic Ca²⁺ increase, protects cells from UVB irradiation–induced MMP‐1 expression and apoptosis. In contrast, sulphoraphane, by decreasing cellular ROS, protects cells from only UVB‐induced apoptosis. Thus, targeting 12‐lipoxygenase may provide a therapeutic approach to improving the health of photo‐aged human skin.     

Protective effect of dl-alpha-tocopherol on the cytotoxicity of ultraviolet B against human skin fibroblasts in vitro

The effect of dl-alpha-tocopherol on ultraviolet light, 280-320 nm (UVB)-induced damage of human skin fibroblasts was studied by measuring the colony-forming ability, unscheduled DNA synthesis (UDS) and malondialdehyde (MDA) production. Regarding the cell toxicity, the values of the mean lethal dose (D0) of UV in fibroblast strains from 5 normal subjects were examined. D0 increased dose-dependently when the cells were cultured in the presence of dl-alpha-tocopherol at the concentration of 10-1000 micrograms/ml. UDS induced by 500 J/m2 UVB irradiation was not altered by treatment of 100 micrograms/ml dl-alpha-tocopherol. MDA did not increase after 500 J/m2 UVB irradiation in the fibroblasts cultured with 100 micrograms/ml dl-alpha-tocopherol, while MDA in the fibroblasts cultured without dl-alpha-tocopherol increased after irradiation. These results suggest that dl-alpha-tocopherol protects human skin fibroblasts against the cytotoxic effect of UVB, and its mechanism seems to be related to inhibition of UV-induced lipid peroxidation or to the antioxidation effect of dl-alpha-tocopherol.     

The effects of the melatonin on ultraviolet-B irradiated cultured dermal fibroblasts

It has been reported that reactive oxygen species (ROS) and oxygen-derived free radicals are generated by ultraviolet (UV) radiation and various chemicals and their important roles in cellular damage and apoptosis are being increasingly recognized. Melatonin is a hormone with multiple functions in humans, produced by the pineal gland and stimulated by beta-adrenergic receptors. Melatonin has been shown to have photo protection properties, but there has been little progress toward identifying the specific mechanisms of its action. To clarify the role of melatonin as a free radical scavenger, in response to ultraviolet-B (UVB) irradiation, we investigated the effects of UVB and melatonin on cytotoxicity, lipid peroxidation, terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick end-labeling (TUNEL) assay and alteration of cell cycle in cultured skin fibroblast. Cell survival curves after UVB irradiation showed dose dependent decrement pattern by trypan blue exclusion assay. Only 56% of dermal fibroblasts were survived at 140 mJ/cm2 UVB irradiation. The damage was associated with cell membrane lipid peroxidation, as shown by accumulation malondialdehyde (MDA). By pre-cultivation with melatonin (10(-9) M), a significant preventive effect was noted on the increase in the absolute number of surviving cells (up to 92.5% of cells were survived) and the levels of MDA were markedly decreased. These finding suggest significant correlation between an increase of lipid peroxide and cell viability. Morphological changes associated with apoptotic cell death were easily distinguished by TUNEL stain. Quantitative analysis of DNA content of skin fibroblasts was evaluated by flow cytometric analysis performed after vital staining with propidium iodide. UVB suppresses the G1 progression induced pre-G1 arrest leading to apoptotic changes of dermal fibroblast and those are blocked by melatonin pre-treatment. The results show the photodynamic effects of UVB that supposes the production of ROS and arrest the cell cycle. Melatonin, which have newly accepted as a potential UV protection properties, is effective membrane peroxidation inhibitor and prevent the pre-G1 arrest when present in relevant concentration during UVB irradiation.     

过表达p53基因和中波紫外线照射对人皮肤成纤维细胞衰老的影响

目的建立稳定过表达野生型p53基因(wtp53)的人皮肤成纤维细胞系,探讨过表达p53基因及中波紫外线(UVB)照射对人皮肤成纤维细胞(HSF)衰老的影响。方法在脂质体lipofectamine TM 2000介导下,将含有wtp53的真核表达质粒pCMV-p53导入HSF中,经G418筛选抗性克隆,扩大培养,建立转染克隆细胞系。用RT-PCR,实时荧光定量PCR和蛋白印迹法分析目的基因及其蛋白表达。亚毒性剂量UVB照射细胞,以染色法检测SAβ-gal活性,MTT法检测细胞增殖能力。结果成功构建过表达p53的HSF细胞系,转染细胞中存在p53基因及蛋白的稳定过表达。过表达p53的细胞株不论UVB照射与否SAβ-gal活性均未见增高,过表达p53可使HSF的增殖能力减弱,但对UVB诱导的细胞生长停滞的影响并不显著。结论过表达p53不能促进HSF的复制衰老和UVB诱导的早期衰老,过表达p53引起的HSF增殖减弱可能与细胞凋亡有关而非衰老。     

P38 and JNK signal pathways are involved in the regulation of phlorizin against UVB‐induced skin damage

Phlorizin is well known to inhibit sodium/glucose cotransporters in the kidney and intestine for the treatment of diabetes, obesity and stress hyperglycaemia. However, the effects of phlorizin against ultraviolet B (UVB) irradiation and its molecular mechanism are still unknown. We examined the effects of phlorizin on skin keratinocyte apoptosis, reactive oxygen species (ROS) production, pro‐inflammatory responses after UVB irradiation and the changes of some signal molecules by in vitro and in vivo assay. We observed that phlorizin pretreatments inhibited HaCaT cell apoptosis and overproduction of ROS induced by UVB. Phlorizin also decreased the expression of UVB‐induced pro‐inflammatory cytokines, such as interleukin‐1 beta (IL‐1β), interleukin‐6 (IL‐6) and interleukin‐8 (IL‐8) at the mRNA level. Topical application of phlorizin on UVB‐exposed skin of nude mice prevented the formation of scaly skin and erythema, inhibited the increase of epidermal thickness and reduced acute inflammation infiltration in skin. Additionally, PCR, Western blot and immunohistochemical data showed that phlorizin reversed the overexpression of cyclooxygenase‐2 (Cox‐2) induced by UVB irradiation both in vitro and in vivo. The activation of p38 and JNK mitogen‐activated protein kinases (MAPK) after UVB irradiation was also inhibited by phlorizin. These findings suggest that phlorizin is effective in protecting skin against UVB‐induced skin damage by decreasing ROS overproduction, Cox‐2 expression and the subsequent excessive inflammation reactions. It seemed that p38 and JNK MAPK signal pathways are involved in the regulation of the protective function of phlorizin.     

中波紫外线对角质形成细胞MMP-1及TIMP-1的影响

目的：研究中波紫外线照射对永生化人角质形成细胞的影响。方法：绘制细胞生长曲线,用不同剂量UVB（30、60、90 mJ/cm2）照射永生化人角质形成细胞,用MTT方法测定UVB照射后细胞的增殖活性,用RT-PCR方法测定HaCaT细胞中MMP-1mRNA和TIMP-1mRNA的表达。结果：UVB照射后,HaCaT细胞的增殖活性受到抑制,MMP-1 mRNA表达增强,TIMP-1 mRNA表达下降,90 mJ/cm2照光组与未照光组比较,差异均有统计学意义。结论：UVB照射可诱导HaCaT细胞损伤和细胞凋亡,促使MMP-1mRNA表达增加,TIMP-1 mRNA表达减少,二者比例失调,这可能与光老化的发生有一定的关系。     

Ultraviolet B radiation regulates cysteine‐rich protein 1 in human keratinocytes

Background: Cysteine‐rich protein 1 (CRP1) is a growth‐inhibitory cytoskeletal protein that is induced by ultraviolet (UV) C radiation radiation in fibroblasts. Our aim was to investigate the effects of UV radiation on CRP1 in keratinocytes, the main cell type subjected to UV radiation in the human body. Methods: The effects of physiologically relevant doses of UVB radiation on CRP1 protein levels were studied in cultured primary keratinocytes and transformed cell lines (HaCaT, A‐431) by immunoblotting. UVB‐induced keratinocyte apoptosis was assessed by flow cytometry and monitoring caspase activity. Expression of CRP1 in human skin in vivo was studied by immunohistochemistry in samples of normal skin, actinic keratosis (AK) representing UV‐damaged skin and squamous cell carcinoma (SCC), a UV‐induced skin cancer. Results: CRP1 expression increased by UVB radiation in primary but not in immortalized keratinocytes. Upon high, apoptosis‐inducing doses of UV radiation, CRP1 was cleaved in a caspase‐dependent manner. In normal skin, CRP1 was expressed in smooth muscle cells, vasculature, sweat glands, sebaceous glands and hair root sheath, but very little CRP1 was present in keratinocytes. CRP1 expression was elevated in basal cells in AK but not in SCC. Conclusion: CRP1 expression is regulated by UVB in human keratinocytes, suggesting a role for CRP1 in the phototoxic responses of human skin.     

Dihydroavenanthramide D prevents UV‐irradiated generation of reactive oxygen species and expression of matrix metalloproteinase‐1 and ‐3 in human dermal fibroblasts

Ultraviolet B (UVB) radiation induces photoageing by upregulating the expression of matrix metalloproteinases (MMPs) in human skin cells. Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component in oats. Although anti‐inflammatory, anti‐atherosclerotic and antioxidant effects have been reported, the antiphotoageing effects of DHAvD are yet to be understood. In this study, we investigated the inhibitory effects of DHAvD on UVB‐induced production of reactive oxygen species (ROS) and expression of MMPs, and its molecular mechanism in UVB‐irradiated human dermal fibroblasts. Western blot and real‐time PCR analyses revealed that DHAvD inhibited UVB‐induced MMP‐1 and MMP‐3 expression. It also significantly blocked UVB‐induced ROS generation in fibroblasts. Additionally, DHAvD attenuated UVB‐induced phosphorylation of MAPKs, activation of NF‐κB and AP‐1. DHAvD regulates UVB‐irradiated MMP expression by inhibiting ROS‐mediated MAPK/NF‐κB and AP‐1 activation. DHAvD may be a useful candidate for preventing UV light‐induced skin photoageing.