MicroRNA-21对瘢痕疙瘩成纤维细胞mTOR信号通路的调控作用研究

目的:探讨MicroRNA(miR)-21对瘢痕疙瘩成纤维细胞哺乳动物雷帕霉素靶蛋白(mTOR)信号通路的调控作用及机制。方法:应用miR-21抑制物(inhibitor)及阴性对照(NC)序列转染人瘢痕疙瘩成纤维细胞后,反转录(RT)-PCR检测miR-21及10号染色体张力缺失蛋白磷酸酶(PTEN)mRNA表达水平;western blot检测m TOR信号通路关键分子PTEN、磷脂酰肌醇3-激酶(PI3K)、蛋白激酶BPKB(p-Akt,又称Akt)及p-mTOR蛋白的表达。生物信息学方法预测miR-21与PTEN mRNA 3′-UTR结合位点,并用双萤光素酶报告基因验证miR-21对PTEN m RNA的靶向作用;四甲基偶氮唑蓝(MTT)法检测瘢痕疙瘩成纤维细胞增殖。结果:miR-21能够靶向调控PTEN m RNA表达,抑制miR-21表达可导致PTEN的m RNA和蛋白表达增加,进而抑制p-Akt及p-mTOR蛋白的表达,从而抑制瘢痕疙瘩成纤维细胞增殖。结论:miR-21可通过靶基因PTEN调控瘢痕疙瘩成纤维细胞mTOR信号通路关键分子p-Akt和p-mTOR的表达。     

白藜芦醇对病理性瘢痕成纤维细胞mTOR信号通路相关分子表达的影响

目的观察白藜芦醇对病理性瘢痕成纤维细胞mTOR信号通路关键分子PI3K、Akt、mTOR表达的影响。方法应用免疫荧光检测PI3K、Akt、mTOR在病理性瘢痕及正常皮肤组织成纤维细胞中的表达;病理性瘢痕成纤维细胞经不同浓度白藜芦醇处理后,分别应用RT-PCR、Western Blot检测PI3K、Akt、mTOR mRNA和蛋白的表达。结果免疫荧光检测结果显示,PI3K、Akt、mTOR在病理性瘢痕成纤维细胞中表达明显增强,且主要表达于细胞核,而在正常皮肤组织成纤维细胞中未见明显表达;RT-PCR及Western Blot检测结果显示,病理性瘢痕成纤维细胞经不同浓度的Res干预后,Akt和mTOR mRNA和蛋白表达量降低,并且呈剂量依赖关系,与对照组相比,差异具有统计学意义(P0.05),而PI3K mRNA和蛋白表达量降低不明显,与对照组相比差异无统计学意义(P0.05)。结论白藜芦醇抑制病理性瘢痕成纤维细胞增殖的机制可能与其下调mTOR信号通路关键分子Akt、mTOR表达有关。     

基于PI3KAkt-Bcl-2通路探讨TSG-6对人瘢痕疙瘩凋亡机制的影响

目的基于PI3KAkt-Bcl-2通路探讨肿瘤坏死因子-α刺激基因(TSG)-6对人瘢痕疙瘩凋亡机制的影响。方法以本院2017年8月—2018年8月通过手术治疗的56例瘢痕疙瘩患者为对象,收集其手术标本,对TSG-6过度表达细胞株(过度表达组)、TSG-6干扰细胞株(干扰组)、TSG-6过度表达对照细胞株(过度表达对照组)、TSG-6干扰对照细胞株(干扰对照组)进行构建,测定以上4组及瘢痕疙瘩成纤维细胞中PI3K、Akt、Bcl-2表达情况。结果过度表达组细胞凋亡率是36.67%,分别较过度表达干扰组的16.67%、干扰组的13.33%、干扰对照组的6.67%、瘢痕疙瘩成纤维细胞的10.00%高,差异有统计学意义(P0.05);过度表达组细胞增殖速度较瘢痕疙瘩成纤维细胞慢,干扰组细胞增殖效应显著较其余组别高,差异有统计学意义(P0.05),过度表达对照组、干扰对照组、瘢痕疙瘩成纤维细胞凋亡对比则差异无统计学意义(P0.05);过度表达组PI3K、Akt、Bcl-2基因mRNA与蛋白表达均显著较干扰组、过度表达对照组、干扰对照组、瘢痕疙瘩成纤维细胞低,干扰组PI3K、Akt、Bcl-2基因mRNA与蛋白表达均较过度表达组、过度表达对照组、干扰对照组、瘢痕疙瘩成纤维细胞高,差异有统计学意义(P0.05),过度表达对照组、干扰对照组、瘢痕疙瘩成纤维细胞对比则差异无统计学意义(P0.05)。结论 TSG-6过度表达可抑制瘢痕疙瘩成纤维细胞中PI3K、Akt、Bcl-2表达,表明TSG-6可对PI3KAkt-Bcl-2通路产生负向调控作用,促进瘢痕疙瘩成纤维细胞凋亡,进而达到抑制瘢痕疙瘩增生的效果。     

4-HPR对瘢痕疙瘩成纤维细胞Procollagen Ⅰ、MMP-1及信号通路PI3K/Akt的影响

目的探讨4-羟苯基维胺(4-hydroxyphenyl-retinamide,4-HPR)对瘢痕疙瘩成纤维细胞的作用及PI3K/Akt信号转导通路的影响。方法通过免疫印迹方法检测人瘢痕疙瘩成纤维细胞中,4-HPR对Ⅰ型前胶原(type I pro-collagen,ProcollagenⅠ)和基质金属蛋白酶-1(matrix metallo-protein-1,MMP-1)蛋白表达水平,观察4-HPR联合TGF-β1、PD98059、SP600125、SB203580及LY294002对瘢痕疙瘩成纤维细胞中相关蛋白表达的影响。结果瘢痕疙瘩成纤维细胞中,4-HPR使ProcollagenⅠ蛋白表达水平明显减少,MMP-1蛋白表达水平明显增加,并且具有4-HPR浓度依赖性(P0.01)。在瘢痕疙瘩成纤维细胞中,4-HPR+TGF-β1组中ProcollagenⅠ蛋白表达水平较TGF-β1组明显降低(P0.01),但P-Smad2和P-Smad3蛋白表达均无显著改变(P0.05)。LY294002组中ProcollagenⅠ蛋白水平与对照组相比显著降低,MMP-1显著升高(P0.01)。但PD98059、SB203580及SP600125组中ProcollagenⅠ和MMP-1蛋白水平与对照组相比未发生明显变化(P0.05),且4-HPR可有效抑制P-Akt蛋白表达水平(P0.01)。结论人瘢痕疙瘩成纤维细胞中,4-HPR可以抑制Ⅰ型前胶原蛋白的表达、上调MMP-1的表达,而这种调控作用可能与PI3K/Akt信号传导通路被削弱有关。     

成纤维细胞活化蛋白在瘢痕疙瘩组织中的表达及意义

 目的:了解成纤维细胞活化蛋白（FAP）在瘢痕疙瘩组织中的表达情况，探讨FAP在瘢痕疙瘩发病机制中的作用。方法:采用免疫组化染色技术检测30例瘢痕疙瘩组织（病例组）和20例正常皮肤组织（对照组）中FAP的表达强度，并比较两组间及瘢痕疙瘩不同临床分级之间FAP表达阳性率的差异。结果:病例组瘢痕疙瘩组织中FAP在成纤维细胞和血管内皮细胞内表达，阳性率为73.33％；对照组正常皮肤组织中未见FAP表达，两组间FAP表达阳性率比较,差异有统计学意义（  X²=26.19,P=0.001）；瘢痕疙瘩临床分级中,轻度与重度之间及中度与重度之间比较，FAP表达阳性率差异均有统计学意义（P值分别为0.002、0.006）。结论:瘢痕疙瘩组织中FAP表达阳性率明显高于正常皮肤组织；瘢痕疙瘩临床分级越严重，FAP表达阳性率越高；FAP可能参与瘢痕疙瘩的发病机制，针对FAP的干预可能有助于瘢痕疙瘩的治疗。     

miR-203及其下游靶基因p63和survivin在瘢痕疙瘩皮损中的表达

目的:检测瘢痕疙瘩皮损中miR-203及其下游靶基因p63和survivin mRNA的表达。方法:Real-time PCR法检测30例瘢痕疙瘩皮损及30例健康对照皮肤中miR-203、p63和survivin mRNA的表达。结果:与健康对照皮肤相比,瘢痕疙瘩皮损中miR-203表达明显下调,其表达量为对照组的0.32±0.16倍(P0.05),靶基因p63和survivin mRNA表达明显上调,其表达量分别为对照组的3.90±0.84倍和5.11±0.93倍(均P0.05)。经Pearson相关性分析,miR-203与survivin间呈负相关(r=-0.40,P0.05),miR-203与p63间呈负相关(r=-0.51,P0.05)。结论:miR-203及其下游靶基因p63和survivin可能参与了瘢痕疙瘩的发病过程。     

细胞周期蛋白A,p21~(WAF1)及C-myc在皮肤瘢痕及瘢痕癌中的表达及意义

目的探讨细胞周期蛋白A(CyclinA),p21WAF1和C-myc在病理性皮肤瘢痕和瘢痕癌中的表达及意义。方法采用免疫组化(SP)法分别检测正常皮肤、皮肤瘢痕和瘢痕癌中CyclinA,p21WAF1和C-myc蛋白的表达,采用原位杂交技术分别检测CyclinA mRNA,p21WAF1 mRNA的表达,并对数据进行统计学分析。结果 CyclinA,p21WAF1及其mRNA在瘢痕癌组织中呈强阳性表达,与正常皮肤组及皮肤瘢痕组比较,差异均有统计学意义(P<0.01);但其在正常皮肤组与瘢痕组比较,差异无统计学意义(P>0.05);C-myc蛋白在正常皮肤、皮肤瘢痕和瘢痕癌组织中的表达分别为弱阳性、阳性和强阳性,差异均有统计学意义(P<0.01)。瘢痕癌中CyclinA与CyclinA mRNA;Cy-clinA与p21WAF1,C-myc;CyclinA mRNA与p21WAF1 mRNA的表达均呈正相关。结论 CyclinA,C-myc的高表达与皮肤瘢痕癌的发生有相关性,这两种因子在瘢痕癌的发生中发挥协同作用;C-myc蛋白的表达可作为皮肤瘢痕癌变早期诊断的一个指标。p21WAF1在瘢痕癌中高表达的意义尚有待于进一步论证。     

miR-384靶向HTRA1影响瘢痕疙瘩成纤维细胞的增殖和凋亡

目的：明确miR-384对瘢痕疙瘩成纤维细胞(KFBs)增殖和凋亡的影响。方法：RT-qPCR和Western Blot检测miR-384和靶向高温需求因子A1（HTRA1）在KFBs和人瘢痕疙瘩皮肤组织中的表达。CCK-8细胞计数试剂盒检测KFBs增殖活力;流式细胞术检测KFBs细胞凋亡;Western Blot检测Ki-67、增殖细胞核抗原（PCNA）、B淋巴细胞瘤-2（Bcl-2）和Bcl-2相关X蛋白（Bax）表达。双荧光素酶报告基因实验验证miR-384对HTRA1的靶向作用。结果：KFBs和人瘢痕疙瘩皮肤组织中miR-384呈低表达,HTRA1呈高表达。转染anti-miR-384后KFBs增殖活力升高,细胞凋亡率降低,Ki-67、PCNA和Bcl-2蛋白表达升高,Bax蛋白表达降低。转染si-HTRA1后KFBs增殖活力降低,细胞凋亡率增加,Ki-67、PCNA和Bcl-2蛋白表达降低,Bax蛋白表达升高。miR-384靶向负性调控HTRA1表达。结论：miR-384可能通过靶向调控HTRA1促进瘢痕疙瘩成纤维细胞增殖,抑制细胞凋亡。     

MAPK在病理性瘢痕和瘢痕癌中的表达

目的探讨MAPK及其mRNA与病理性瘢痕上皮和瘢痕癌的相关性。方法采用免疫组织化学(SP)法和核酸分子原位杂交技术分别检测正常皮肤表皮,病理性瘢痕上皮和瘢痕癌三组组织中MAPK蛋白和mRNA的表达;结合图像分析,分别计算三组组织中所检指标的平均光密度和阳性面积,所有数据运用SPSS16.0软件包进行统计学分析。结果 MAPK蛋白和mRNA在正常皮肤表皮、病理性瘢痕上皮和瘢痕癌组织中分别呈阴性表达、弱阳性表达和强阳性表达。瘢痕癌组表达水平(阳性面积)、表达强度(平均光密度)与正常皮肤、病理性瘢痕组比较,差异均有统计学意义(P均<0.01);但正常皮肤组与病理性瘢痕组比较,差异无统计学意义(P>0.05)。且在瘢痕癌组织中,MAPK及其mRNA的表达呈正相关。结论 MAPK及其mRNA在瘢痕癌中的高表达,与瘢痕癌的发生有相关性,可作为瘢痕癌靶向治疗的靶点,但在病理性瘢痕上皮中的表达不具有特殊意义。     

宫颈癌细胞外泌体miR-21调控PTEN/PI3K/AKT信号轴对淋巴管生成的影响

目的探究宫颈癌细胞外泌体miR-21对淋巴管生成的影响及机制。方法提取宫颈上皮细胞HcerEpic、宫颈癌细胞HeLa和C-33A三者分泌的外泌体(HcerEpic exo、HeLa exo和C-33A exo),采用实时荧光定量PCR(qRT-PCR)检测HcerEpic、HeLa、C-33A及其所分泌外泌体中miR-21的表达;HeLa细胞转染miR-21 mimic、miR-21 inhibitor、Negative control,提取转染后HeLa细胞的外泌体(HeLa/miR-21 mimic exo、HeLa/miR-21 inhibitor exo、HeLa/miR-NC exo),将上述外泌体与淋巴管内皮细胞HLECs共孵育后检测HLECs中miR-21的表达及小管生成能力;采用双荧光素酶报告基因验证miR-21和酪氨酸磷酸酶基因(PTEN)的靶向关系,检测转染siRNA抑制蛋白(PTEN)表达后的小管形成及磷脂酰肌醇3-激酶(PI3K)和蛋白激酶B(AKT)磷酸化水平;将HeLa/miR-21 mimic exo与HLECs共孵育后转染PTEN质粒(HeLa/miR-21 mimic exo+PTEN),然后检测小管形成及PI3K和AKT磷酸化水平。结果 miR-21高表达于HeLa、C-33A及二者外泌体;与HeLa exo、C-33A exo、HeLa/miR-21 mimic exo共孵育后HLECs中miR-21表达显著上调,HeLa/miR-21 mimic exo显著促进小管形成;PTEN为miR-21靶基因,抑制PTEN表达后,HLECs小管形成及PI3K和AKT磷酸化水平均显著增加;HeLa/miR-21 mimic exo+PTEN HLECs小管形成及PI3K和AKT磷酸化水平均显著低于HeLa/miR-21 mimic exo。结论外泌体miR-21通过激活PTEN/PI3K/AKT信号通路而诱导HLECs淋巴管生成。     

PTEN基因在皮肤肿瘤中的研究进展

PTEN基因是一个抑癌基因,其缺失、突变和表达减少可存在多种皮肤肿瘤中.PTEN基因主要通过PI3K/Akt、FAK/p130途径及Shc/ras/MARK途径影响细胞的分化、凋亡、移动及信号转导等方面,参与皮肤肿瘤的发生发展,与皮肤肿瘤的恶性转化有着密切的关系.因此,PTEN基因在保持皮肤内环境稳定和抑制皮肤肿瘤的发生方面起着重要的作用.概述紫外线辐射对PTEN功能的调节及PTEN基因在多种皮肤肿瘤发生发展中的作用.     

PTEN、Akt在寻常型银屑病皮损中的表达及意义

目的:检测PTEN、Akt蛋白在寻常型银屑病皮损中的定位及表达水平,探讨其在银屑病角质形成细胞异常增殖中的作用。方法:收集30例寻常型银屑病患者的皮损及30例健康对照皮肤组织,采用免疫组化及Western blot法检测PTEN、Akt的表达,比较两组之间PTEN、Akt的表达水平。结果:免疫组化结果显示,PTEN、Akt蛋白均主要表达于表皮角质形成细胞的胞浆中,其中PTEN在寻常型银屑病皮损的角质形成细胞中为淡黄色颗粒,在健康对照皮肤角质形成细胞中为深黄色颗粒;Akt在寻常型银屑病皮损的角质形成细胞中为棕黄色颗粒,在健康对照皮肤角质形成细胞中为浅黄色颗粒。Western blot结果显示,与健康对照皮肤比较,寻常型银屑病皮损中PTEN蛋白的表达明显下调[(0.78±0.21)vs(1.46±0.34),t=9.39,P0.05],Akt蛋白的表达水平明显上调[(1.83±0.28)vs(0.92±0.16),t=15.56,P0.05]。结论:PTEN的低表达、Akt的高表达可能促进了银屑病皮损中角质形成细胞的异常增殖。     

miRNA-188-5p表达下调通过调控PTEN/Akt途径抑制皮肤鳞状细胞癌细胞的增殖和侵袭能力

【摘要】 目的 探讨miRNA-188-5p（miR-188-5p）在皮肤鳞状细胞癌（鳞癌）组织和细胞中的表达，分析其表达下调对皮肤鳞癌细胞增殖和侵袭能力的影响。方法 2012年11月至2018年10月在河南省新乡医学院第一附属医院收集50例手术切除的皮肤鳞癌组织及50例癌旁正常皮肤组织。实时荧光定量PCR（qPCR）检测皮肤鳞癌组织、癌旁正常皮肤组织、皮肤鳞癌细胞系SCL-1、A431、HSC-5和人永生化角质形成细胞株HaCaT细胞中miR-188-5p的表达。培养的A431和HSC-5细胞分别分为2组：miR-188-5p抑制剂组和阴性对照组，对转染miR-188-5p抑制剂的细胞和阴性对照组细胞，通过qPCR检测miR-188-5p的相对表达（2-△△Ct），并以CCK8法和Transwell小室分别检测各组细胞的增殖活性和侵袭能力。双荧光素酶报告实验检测miR-188-5p和PTEN的相互作用，Western印迹法检测PTEN、总Akt（t-Akt）和磷酸化Akt（p-Akt）的表达。两独立样本比较采用t检验。结果 皮肤鳞癌组织中miR-188-5p的相对表达（5.213 ± 3.138）显著高于癌旁正常皮肤组织（1.010 ± 0.364，t = 9.187，P < 0.001）。SCL-1、A431和HSC-5细胞中miR-188-5p的表达（3.858 ± 0.163、7.068 ± 0.262和4.572 ± 0.413）均显著高于HaCaT细胞（1.079 ± 0.300，t = 17.890、21.110和8.737，均P < 0.05）。与阴性对照组相比，miR-188-5p抑制剂组A431和HSC-5细胞miR-188-5p表达显著下调（均P < 0.01），细胞增殖和侵袭能力下降（均P < 0.05）。双荧光素酶报告实验显示，miR-188-5p表达下调显著上调A431和HSC-5细胞中PTEN的表达，但抑制p-Akt的表达。结论 miR-188-5p在皮肤鳞癌组织和细胞中高表达，且miR-188-5p表达下调可能通过调控PTEN/Akt途径，抑制皮肤鳞癌细胞增殖活性和侵袭能力。     

PI3K/Akt/mTOR信号通路与皮肤肿瘤靶向治疗

P13K/AkdmTOR信号转导通路是促存活通路,在很多肿瘤中组成性激活.该通路激活的机制是肿瘤抑制基PTEN功能缺失、P13K扩增或突变、Akt扩增或突变.近年研究发现,该通路失常可促进肿瘤细胞的存活和生长,持续活化在皮肤肿瘤发病中起着重要的作用,已经发现抑制该通路中的信号分子可以治疗多种肿瘤,目前,针对该通路的抑制药物也在研究中,主要集中于mTOR抑制剂.     

mTOR as a potential therapeutic target for treatment of keloids and excessive scars

Keloid is a dermal fibroproliferative disorder characterized by excessive deposition of extracellular matrix (ECM) components such as collagen, glycoproteins and fibronectin. The mammalian target of rapamycin (mTOR) is a serine/theronine kinase which plays an important role in the regulation of metabolic processes and translation rates. Published reports have shown mTOR as regulator of collagen expression and its inhibition induces a decrease in ECM deposition. Our aim was to investigate the role of mTOR in keloid pathogenesis and investigate the effect of rapamycin on proliferating cell nuclear antigen (PCNA), cyclin D1, collagen, fibronectin and alpha-smooth muscle actin (alpha-SMA) expression in normal fibroblasts (NF) and keloid fibroblasts (KF). Tissue extracts obtained from keloid scar demonstrated elevated expression of mTOR, p70KDa S6 kinase (p70S6K) and their activated forms, suggesting an activated state in keloid scars. Serum stimulation highlighted the heightened responsiveness of KF to mitogens and the importance of mTOR and p70S6K during early phase of wound healing. Application of rapamycin to monoculture NF and KF, dose- and time-dependently downregulates the expression of cytoplasmic PCNA, cyclin D1, fibronectin, collagen and alpha-SMA, demonstrating the anti-proliferative effect and therapeutic potential of rapamycin in the treatment of keloid scars. The inhibitory effect of rapamycin was found to be reversible following recovery in the expression of proteins following the removal of rapamycin from the culture media. These results demonstrate the important role of mTOR in the regulation of cell cycle and the expression of ECM proteins: fibronectin, collagen and alpha-SMA.     

Interleukin-18 system plays an important role in keloid pathogenesis via epithelial-mesenchymal interactions

Summary Background Keloid scarring is a dermal fibroproliferative disorder characterized by increased fibroblast proliferation and excessive production of collagen and extracellular matrix (ECM) components. To date, the role of cytokines in keloid pathogenesis has not been completely unravelled. Interleukin (IL)‐18 is a pro‐inflammatory cytokine that plays important roles in wound healing, fibrogenesis and carcinogenesis. Objectives Our aim was to study the role of the IL‐18 system in keloid pathogenesis. Materials and methods Expression and localization of IL‐18 and its receptor (IL‐18R) were investigated in normal skin and keloid tissues using Western blot and immunohistochemistry. We further studied the expression of the IL‐18 system in normal and keloid‐derived cell lines in a coculture model. Results Results from Western blot and immunohistochemistry revealed that IL‐18, IL‐18Rα and IL‐18Rβ expression was elevated in keloid tissue compared with normal skin tissue. Studies on the expression of IL‐18 and its antagonist, IL‐18 binding protein (IL‐18BP), using a coculture model demonstrated severe IL‐18/IL‐18BP imbalance in keloid keratinocyte/keloid fibroblast (KK/KF) cocultures with significant elevation of bioactive IL‐18 whereas IL‐18BP levels remained the same. This overproduction of bioactive IL‐18 in keloid cocultures could be due to increased caspase‐1 and decreased caspase‐3 expression in keloid tissue, as well as decreased soluble IL‐10 levels observed in keloid cocultures. The important inductive effects of IL‐18 on KFs were further underscored by the observation that exposure of KF to IL‐18 resulted in increased collagen and ECM component synthesis, and increased secretion of profibrotic cytokines such as IL‐6 and IL‐8. Finally, the addition of phosphatidylinositol 3‐kinase (PI3K), mitogen activation protein kinase (MAPK), specificity protein 1 (Sp1) and mammalian target of rapamycin (mTOR) inhibitors inhibited IL‐18 secretion in keloid cocultures. Conclusions The present study has proven that the IL‐18 system plays an important role in keloid pathogenesis via epithelial–mesenchymal interactions. It also suggests a therapeutic potential of PI3K, MAPK, Sp1 and mTOR inhibitors in the treatment of keloid scarring.     

麦冬皂苷B通过抑制PI3K/Akt/mTOR通路诱导人黑色素瘤A375细胞凋亡

目的探讨麦冬皂苷B对人黑色素瘤(Melanoma)A375细胞增殖,凋亡和细胞周期的影响以及相关机制。方法麦冬皂苷B处理A375细胞后,采用CCK-8法检测细胞活力;流式细胞仪检测A375细胞周期变化及细胞凋亡水平;Hoechst33258荧光染色法观察细胞凋亡形态;免疫印迹法检测麦冬皂苷B对A375细胞PI3K,p-PI3K,AKT,p-AKT蛋白以及通路下游凋亡相关蛋白Bcl-2,Bax,Cleaved-caspase3表达的影响。结果麦冬皂苷B能抑制A375细胞增殖活力及PI3K/Akt/mTOR通路的活化;麦冬皂苷B促进了A375细胞内Bax和Cleaved-caspase 3的表达,抑制Bcl-2表达,诱导人黑色素瘤细胞发生凋亡;麦冬皂苷B阻滞了A375细胞细胞周期,G0/G1期细胞比例明显升高;PI3K/Akt/mTOR通路活化剂IGF-1处理A375细胞后抑制了麦冬皂苷B的上述作用。结论麦冬皂苷B能抑制A375细胞的增殖,诱导细胞发生凋亡,阻滞细胞周期于G0/G1期。     

Inhibition of ANGPT2 activates autophagy during hypertrophic scar formation via PI3K/AKT/mTOR pathway

BackgroundHypertrophic scar (HS), a fibroproliferative disorder caused by aberrant wound healing following skin injuries such as burns, lacerations and surgery, is characterized by invasive proliferation of fibroblasts and excessive extracellular matrix (ECM) accumulation. The dysregulation of autophagy is the pathological basis of HS formation. Previously, angiopoietin-2 (ANGPT2) was found to be overexpressed in HS fibroblasts (HSFs) compared with normal skin fibroblasts. However, whether ANGPT2 participates in the process of HS formation and the potential molecular mechanisms are not clear.ObjectiveThis study is intended to figure out the role of ANGPT2 and ANGPT2-mediated autophagy during the development of HS.MethodsRT-qPCR was used to detect ANGPT2 expression in HS tissues and HSFs. HSFs were transfected with sh-ANGPT2 to knock down ANGPT2 expression and then treated with MHT1485, the mTOR agonist. The effects of sh-ANGPT2 or MHT1485 on the proliferation, migration, autophagy and ECM accumulation of HSFs were evaluated by CCK-8 assay, Transwell assay and western blotting. The expression of PI3K/Akt/mTOR pathway-related molecules (p-PI3K, p-Akt and p-mTOR) was assessed by western blotting.ResultsANGPT2 expression was markedly upregulated in HS tissues and HSFs. ANGPT2 knockdown decreased the expression of p-PI3K, p-Akt and p-mTOR. ANGPT2 knockdown activated autophagy and inhibited the proliferation, migration, and ECM accumulation of HSFs. Additionally, the treatment of MHT1485, the mTOR agonist, on ANGPT2-downregulated HSFs, partially reversed the influence of ANGPT2 knockdown on HSFs.Study limitationsThe study lacks the establishment of more stable in vivo animal models of HS for investigating the effects of ANGPT2 on HS formation in experimental animals.ConclusionsANGPT2 downregulation represses growth, migration, and ECM accumulation of HSFs via autophagy activation by suppressing the PI3K/Akt/mTOR pathway. Our study provides a novel potential therapeutic target for HS.