Prokineticin 2/Bv8 is expressed in Kupffer cells in liver and is down regulated in human hepatocellular carcinoma

AIM： TO study the implication of prokineticin 1 （PKI/EGVEGF） and prokineticin 2 （PK2/13v8） in hepatocellular carcinoma angiogenesis.METHODS： The gene induction of PK1/EG-VEGF and PK2/Bv8 was investigated in 10 normal, 28 fibrotic and 28 tumoral livers by using real time PCR. Their expression was compared to the expression of VEGF （an angiogenesis marker）, vWF （an endothelial cell marker） and to CD68 （a monocyte/macrophage marker）. Furthermore, the rnRNA levels of PK1/EG-VEGF, PK2/Bv8, prokineticin receptor 1 and 2 were evaluated by real time PCR in isolated liver cell populations. Finally, PK2/Bv8 protein was detected in normal liver paraffin sections and in isolated liver cells by immunohistochernistry and immunocytochemistry.RESULTS： PK2/Bv8 mRNA but not PK1/EG-VEGF was expressed in all types of normal liver samples examined. In the context of liver tumor development, we reported that PK2/13v8 correlates only with CD68 and showed a significant decrease in expression as the pathology evolves towards cancer. Whereas, VEGF and vWF mRNA were significantly upregulated in both fibrosis and HCC,as expected. In addition, out of all isolated liver cells examined, only Kupffer cells （liver resident macrophages） express significant levels of PK2/Bv8 and its receptors, prokineticin receptor 1 and 2.CONCLUSION： In normal liver PK2/Bv8 and its receptors were specifically expressed by Kupffer cells. PK2/Bv8 expression decreased as the liver evolves towards cancer and did not correlate with HCC angiogenesis.

BV8及其抗体与血管新生的关系

BV8作为一种新发现的分泌蛋白,在内分泌腺、心血管、肾脏等器官血管新生中发挥重要作用,尤其与CD11b+Gr1+髓样细胞相关的肿瘤血管新生和发展密切相关。同时,动物模型研究证实,抗BV8抗体能明显抑制肿瘤中新生血管形成,从而起到显著的抗实体肿瘤作用。该综述对BV8的结构、功能、机制及其在疾病中的作用进行了系统回顾,以期为恶性肿瘤抗血管疗法新靶点的开发及后续BV8的研究提供新的思路和方向。

G-CSF诱导小鼠骨髓中性粒细胞表达Bv8促进U14宫颈癌细胞成瘤及血管生成

目的：探讨粒细胞集落刺激因子（G-CSF）诱导小鼠骨髓中性粒细胞（PMN）生成Bv8的作用,以及其对肿瘤生长和肿瘤血管生成的作用。方法：体外实验：实时荧光定量聚合酶链式反应检测细胞内Bv8的mRNA表达,Western Blot检测PMN中细胞外调节蛋白激酶（ERK）蛋白磷酸化改变。体内实验：PMN与U14小鼠宫颈癌细胞混合成瘤,G-CSFR真核表达载体干扰G-CSF作用,抗Bv8抗体阻断Bv8作用,比较各组瘤重,免疫组织化学法检测各组肿瘤组织中的血管密度。结果：体外实验中：G-CSF刺激后,PMN中Bv8的mRNA水平明显升高（P=0.005）,PMN中ERK磷酸化水平明显升高（P=0.006 7）。在G-CSF作用时加入特异性ERK抑制剂PD98059后,Bv8的mRNA水平、PMN中磷酸化ERK蛋白的水平与G-CSF刺激组相比均明显下降（P=0.008 9和0.009 8）。体内实验中：NBM-PMN抑制肿瘤生长及血管生成,TBM-PMN促进肿瘤生长及血管生成,加入G-CSFR及抗Bv8抗体后,TBM-PMN的促肿瘤生长及促血管生成作用减弱。结论：G-CSF刺激骨髓PMN生成Bv8,参与了宫颈癌肿瘤微环境改变小鼠骨髓PMN功能的过程,使其具有促进肿瘤生长及血管生成的潜能。

PKs的生物学功能

PKs是最近发现的多功能分泌蛋白,由PK1和PK2组成.在不同的系统中,它们通过两个高度同源G-蛋白偶联受体发挥各种生物学功能.它们与神经和血管的形成以及免疫应答的调节有关,并且对生殖系统的正常生理和促性腺激素释放激素系统的发育都有很大的影响.

Prokineticins信号通路的生物学功能

Prokineticins信号通路是由两种多功能分泌蛋白（PK1和PK2）和G蛋白偶联受体（PKR1和PKR2）组成。研究发现Prokineticins信号与胃肠道运动，神经和血管生成，昼夜节律调节，造血作用和胎盘发育等有关。近期研究还发现Prokineticins信号通路在出生后小鼠心肾组织的新生血管生成，心肌细胞存活方面起重要作用。