背景:脉冲染料激光(PDL)是葡萄酒色斑(PWS)的主要治疗方法,但相当多的患者表现出低间隙。疗效差的原因与PDL诱导的血管生成有关。血管内皮生长因子(VEGF)在PDL诱导的血管生成中起重要作用,可以激活内皮细胞中VEGF受体(VEGFR)的酪氨酸激酶活性。它引发了全方位的回应,然后参与血管生成的调节。Tivozanib是VEGFR酪氨酸激酶活性的抑制剂,可以阻断VEGF的促血管生成作用并降低血管通透性。
方法:采用不同能量密度的PDL照射大鼠腹部皮肤。根据照射区域的一般和病理变化,选择结痂较小,血管效应较强的能量密度为8J/cm2用于后续实验。把老鼠腹部的皮肤分成四个区域,以8J/cm2的能量密度均匀照射其中三个,并将不同浓度的Tivozanib涂层剂施加到激光照射区域,并将它们分组如下:(1)空缺组,(2)对照组,(3)0.5%替沃扎尼组,(4)1%替沃扎尼组。相机和皮肤镜用于观察皮肤变化。苏木精-伊红染色,免疫组织化学染色,和血管计数以检测真皮血管再生。进行转录组测序和实时聚合酶链反应(PCR)以阐明机制并验证可靠性。
结果:与对照组相比,0.5%Tivozanib组和1%Tivozanib组的血管数量在第7、10和14天明显减少。1%替沃扎尼组血管数量较0.5%替沃扎尼组显著减少,表明Tivozanib成功地抑制了PDL诱导的血管生成,1%替沃扎尼的抑制作用比0.5%替沃扎尼的抑制作用更显著。转录组测序结果显示共有588个显著差异表达的基因,包括90个上调基因和498个下调基因。基因本体论(GO)和京都基因与基因组百科全书(KEGG)富集分析表明,显著差异表达的基因主要富集在与血管生成密切相关的代谢途径中。最后,实时PCR用于验证具有较高表达差异的基因,排名最高,与血管生成密切相关,即,Cxcl1,Cxcl2,Cxcl3,Cxcl6,Ccl3,Csf3,IL1β,iNOS,Mmp9,Mmp13,Plau,Ets1、Spp1、Nr4a1。结果与转录组测序结果的趋势一致,这证明了本研究的可靠性。
结论:本研究探讨了Tivozanib对PDL诱导的血管生成的抑制作用,为临床PWS的治疗提供了新的思路。转录组测序探索了该机制,为后期深入研究提供了可靠线索。
BACKGROUND: Pulsed dye laser (PDL) is the main treatment for port wine stain (PWS), but a considerable number of patients show low clearances. The reason for the poor efficacy is related to PDL-induced angiogenesis. Vascular endothelial growth factor (VEGF) plays an important role in PDL-induced angiogenesis and can activate the tyrosine kinase activity of VEGF receptor (VEGFR) in endothelial cells. It triggers a full range of responses, and then participates in the regulation of angiogenesis. Tivozanib is an inhibitor of VEGFR tyrosine kinase activity, which can block the pro-angiogenic effect of VEGF and reduce vascular permeability.
METHODS: Different energy densities of PDL were used to irradiate the abdominal skin of rats. According to the general and pathological changes of the irradiated area, the energy density of 8 J/cm2 with smaller scab and stronger vascular effect was selected for follow-up experiments. Divided the rat abdomen skin into four areas, irradiated three of them uniformly with an energy density of 8 J/cm2 , and applied different concentrations of Tivozanib coating agent to the laser irradiation area, and grouped them as follows: (1) vacant group, (2) control group, (3) 0.5% Tivozanib group, (4) 1% Tivozanib group. Camera and dermoscopy were used to observe skin changes. Hematoxylin-eosin staining, immunohistochemical staining, and blood vessels were counted to detect dermal vascular regeneration. Transcriptome sequencing and real-time polymerase chain reaction (PCR) were conducted to elucidate the mechanism and validate the reliability.
RESULTS: The number of blood vessels in the 0.5% Tivozanib group and 1% Tivozanib group was significantly reduced on the 7, 10, and 14 days compared with the control group. The number of blood vessels in the 1% Tivozanib group was significantly reduced compared with the 0.5% Tivozanib group, indicating that Tivozanib successfully inhibited PDL-induced angiogenesis, and the inhibitory effect of 1% Tivozanib was more significant than that of 0.5% Tivozanib. Transcriptome sequencing results showed a total of 588 significantly differentially expressed genes, including 90 upregulated genes and 498 downregulated genes. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the significantly differentially expressed genes were mainly enriched in the metabolic pathways which were closely related to angiogenesis. Finally, real-time PCR was used to verify the genes with higher expression differences, the top ranking and closely related to angiogenesis, namely, Cxcl1, Cxcl2, Cxcl3, Cxcl6, Ccl3, Csf3, IL1β, iNOS, Mmp9, Mmp13, Plau, Ets1, Spp1, Nr4a1. The results were consistent with the trend of transcriptome sequencing results, which proved the reliability of this study.
CONCLUSIONS: This study explored the inhibitory effect of Tivozanib on PDL-induced angiogenesis, and provided a new idea for the treatment of clinical PWS. Transcriptome sequencing explored the mechanism and provided reliable clues for later in-depth research.