Immunohistochemical demonstration and semi-quantitation of vascular endothelial growth factor in recurrent versus non-recurrent nasal polyps

Objective The expression of some growth factors in nasal polyps has been examined, although investigations addressing the reason for recurrence in some patients are lacking. Vascular endothelial growth factor (VEGF) is expressed by inflammatory cells, as well as by endothelial and epithelial cells of nasal polyps. To determine whether VEGF may play a role in the recurrence of nasal polyps, we aimed to compare VEGF expression in recurrent versus non-recurrent polyps. In addition, expression in polyps from asthmatic patients was compared with that in polyps from non-asthmatics.

Material and Methods A total of 30 patients with newly diagnosed nasal polyposis were included. Polypectomy was performed at enrolment in the long-term follow-up study. Fifteen patients had only 1 polypectomy (non-recurrence group; median observation period 81 months) and 15 had a median of 6.4 polypectomies (multiple recurrence group; median observation period 108 months). Five of 10 patients with asthma belonged to the non-recurrence group and 5 to the recurrence group. The polyp obtained at the initial polypectomy was examined for expression of VEGF by immunohistochemistry, using a polyclonal antibody. A blinded semi-quantitation and comparison of the intensity of immunolabelling were performed in recurrent versus non-recurrent polyps, as well as in asthmatics versus non-asthmatics.

Results VEGF expression was seen as varying staining of the polyp surface and gland epithelium, as well as of the vessel endothelium and some stromal mono- and polymorphonuclear leukocytes. Semi-quantitation of the staining intensity showed no significant differences between recurrent and non-recurrent polyps, or between asthmatics and non-asthmatics.

Conclusion Our findings indicate that the level of immunohistochemical expression of VEGF in recurrent and non-recurrent nasal polyposis is equivalent. Thus, the level of VEGF expression cannot predict a subsequent recurrence. The expression of VEGF is not upregulated in patients with asthma. Further studies are needed to determine the role of VEGF in nasal polyposis, with special reference to different stages of polyp formation, vascularization and growth.     

Basic fibroblast growth factor expression in recurrent versus non-recurrent nasal polyposis

Various growth factors are expressed in nasal polyps, and some of these have been suggested to play a role in polyp formation. A potential relation between growth factor expression and polyp recurrence, however, is undetermined. Basic fibroblast growth factor (bFGF) is expressed in mononuclear cells, as well as in endothelial and epithelial surface and gland cells of nasal polyps. To determine whether bFGF may play a role in the recurrence of nasal polyps, the present study aimed at a comparison of bFGF expression in recurrent versus non-recurrent polyps. Further, the expression in polyps from asthmatic patients was compared with that from non-asthmatics. Thirty patients with newly diagnosed nasal polyposis were included. Polypectomy was performed at entry to the long-term follow-up study. Fifteen patients only had one polypectomy (no recurrence group, with a median observation time of 81 months). Fifteen patients had a median of 6.4 polypectomies (multiple recurrence group, with a median observation time of 108 months). Five of nine patients with asthma belonged to the non-recurrence group and four to the recurrence group. The polyp from the entrance polypectomy was examined for expression of bFGF by immunohistochemistry, using a polyclonal antibody. A masked semi-quantification of staining intensity was performed in recurrent versus non-recurrent polyps, as well as in asthmatics versus non-asthmatics. bFGF expression was seen as varying staining of the polyp surface and gland epithelium, as well as of some mononuclear cells and some fibroblast-like cell profiles in the polyp stroma. Vascular endothelium was labeled occasionally. Semi-quantification of the staining intensity showed no significant differences between recurrent and non-recurrent polyps, or between asthmatics and non-asthmatics. We conclude that the level of immunohistochemical expression of bFGF in recurrent and non-recurrent nasal polyposis is equivalent. Thus, the level of bFGF expression in the primary polyp can not predict a subsequent recurrence. The expression of bFGF is not up-regulated in patients with asthma. Further studies are needed to determine a potential role of bFGF in nasal polyposis, with special reference to different stages of polyp formation and growth.     

黏附分子及血管内皮生长因子在鼻息肉中的表达

目的 探讨细胞间黏附分子-1（ICAM-1）、血管细胞黏附分子-1（VCAM-1）以及血管内皮生长因子（VEGF）在鼻息肉中的表达与意义。方法25例鼻息肉标本和9例下鼻甲黏膜标本，分别行ICAM-1、VCAM-1、VEGF免疫组化染色和HE染色，光镜下观察比较各种分子表达水平。结果 鼻息肉中可见大量嗜酸性粒细胞（EOS）浸润。ICAM-1、VCAM-1和VEGF均可表达于鼻息肉血管内皮、间质及炎症细胞，且在鼻息肉血管内皮、间质及浸润炎症细胞中的表达趋势呈现正相关关系。结论 ICAM-1、VCAM-1可能与EOS等炎症细胞附壁浸润活化过程关系密切，VEGF可能启动并加强这一病理变化。它们的协同作用可能参与了鼻息肉的病理过程。     

鼻息肉中血管内皮生长因子和转化生长因子β1的表达

目的　探讨血管内皮生长因子 血管通透性因子 (vascularendothelialgrowthfactor vasularpermeabilityfactor,VEGF VPF)和转化生长因子β1 (transforminggrowthfactor β1 ,TGF β1 )在鼻息肉组织中的表达及意义。方法　 34例鼻息肉标本及 30例中鼻甲粘膜标本行VEGF VPF及TGF β1 的免疫组化染色 ,光镜观察。结果　①VEGF VPF在鼻息肉组织的血管内皮细胞和腺体细胞的表达明显高于中鼻甲组织 (P <0 .0 1和P <0 .0 5 ) ;②TGF β1 在鼻息肉组织的细胞外基质和固有层浸润细胞的表达明显高于中鼻甲组织 (P <0 .0 0 5 ) ;③鼻息肉组织中TGF β1 阳性细胞的形态及分布相似于嗜酸粒细胞 ;④VEGF VPF与TGF β1 阳性表达与鼻息肉的临床分型无关 (P >0 .0 5 )。结论　①VEGF VPF对鼻息肉发生过程中组织极度水肿的产生可能有非常重要的作用 ;②TGF β1 可能直接参与鼻息肉的病理变化 ,导致上皮基底膜增厚和基质纤维化 ;③嗜酸粒细胞可能为鼻息肉中TGF β1 的主要来源。     

鼻息肉中血管内皮生长因子mRNA的检测与意义

目的 :检测鼻息肉组织和鼾症下鼻甲粘膜组织中的血管内皮生长因子 (VEGF) m RN A水平的表达 ,了解其在慢性炎症过程中的作用。方法 :取 6例行下鼻甲切除术的下鼻甲粘膜和 7例鼻息肉切除术的鼻息肉标本 ,用半定量的反转录 -聚合酶链反应 (RT- PCR)方法检测 VEGF的 m RNA表达。结果 :RT- PCR结果显示在鼻息肉组织中 V EGF的表达较鼾症患者下鼻甲粘膜组织明显升高。结论 :鼻息肉组织中 VEGF的表达显著升高 ,推测 VEGF在鼻息肉的形成、生长及复发过程中具有极其重要的作用。     

血管内皮生长因子和CD34在鼻息肉中的表达及临床意义

目的探讨血管内皮生长因子（Vascular endothelial growth factor,VEGF）、CD34在人各型鼻息肉组织中的表达及临床意义。方法采用免疫组织化学SP法,检测67例鼻息肉（Ⅱ型1期14例,Ⅱ型2期18例,Ⅱ型3期20例,Ⅲ型15例）和20例下鼻甲（对照组）组织中VEGF、CD34蛋白的表达情况,对CD34阳性微血管进行计数[微血管密度（microvessel density,MVD）]。结果鼻息肉Ⅱ型1期、Ⅱ型2期、Ⅱ型3期、Ⅲ型中,VEGF表达分别为17．35±5．29、19．13±4．85、36．76±4．38、38．49±6．07。CD34表达（MVD）分别为13．26±2．05、14．72±3．86、26．40±2．71、27．97±3．34。11型3期、Ⅲ型鼻息肉组织中VEGF、CD34的表达较Ⅱ型1期、Ⅱ型2期鼻息肉组织中显著升高（P〈0．05）。结论VEGF、CD34表达与鼻息肉发生、发展有关,对其检测有助于判断鼻息肉的发展趋势。     

Expression of vascular endothelial growth factor and transforming growth factor-beta 1 in nasal polyps]

OBJECTIVE: To study the expression and significance of vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) and transforming growth factor-beta 1(TGF-beta 1) in nasal polyps. METHODS: Expression of VEGF/VPF and TGF-beta 1 in nasal polyps from 34 patients and middle turbinates from 30 patients with deviation of nasal septum was prospectively studied with immunohistochemistry. Tissue sections were observed under optical microscope. RESULTS: (1) The VEGF/VPF positivity in vascular endothelium and in glandular cell was significantly higher in nasal polyps than in middle turbinates (P < 0.01 and P < 0.05, respectively); (2) The TGF-beta 1 positivity in extracellular matrix and in cells in the stroma was significantly higher in nasal polyps than in middle turbinates(P < 0.005); (3) The distribution and shape of TGF-beta 1 expressing cells in nasal polyps were similar to that of eosinophil, their positivities were significantly correlative; (4) The positivity of VEGF/VPF and TGF-beta 1 did not correlate with clinical type in nasal polyps (P > 0.05). CONCLUSION: (1) The VEGF/VPF may play a key role in the formation of heavy edema of nasal polyps; (2) The TGF-beta 1 may contribute to some of the pathologic changes observed in nasal polyps, such as thickening of the epithelial basement membrane and stromal fibrosis; (3) Eosinophils in nasal polyps represent a major source of TGF-beta 1.     

鼻息肉中单核细胞趋化蛋白1和血管内皮生长因子的表达

目的明确单核细胞趋化蛋白1（monocyte chemotactic protein 1，MCP-1）和血管内皮生长因子（vascular endothelial growth factor，VEGF）在鼻息肉组织中的表达及其相关性，初步探讨MCP-1与鼻息肉发生的关系。方法取40例鼻息肉组织和25例下鼻甲组织，应用原位杂交和免疫组织化学等方法检测MCP-1和VEGF mRNA及蛋白质的表达。结果鼻息肉组织中MCP-1和VEGF mRNA及蛋白质的表达均高于对照组下鼻甲组织（P值均〈0．01）；鼻息肉组织中MCP-1和VEGF蛋白质的表达呈正相关（r=0．871，P〈0．05）。结论鼻息肉组织中MCP-1和VEGF表达增加，二者协同作用可能是鼻息肉形成的原因之一。     

Immunohistochemical demonstration of vascular endothelial growth factor in vestibular schwannomas correlates to tumor growth rate

OBJECTIVE: Vascular endothelial growth factor (VEGF) is one of the most potent mediators of angiogenesis, which is a mandatory process during tumor growth. The present objectives were to determine expression of VEGF in vestibular schwannomas by immunohistochemistry and to examine a possible correlation with symptom duration, tumor size, or growth rate. STUDY DESIGN: Retrospective patient file review; immunohistochemistry and light microscopy of vestibular schwannomas removed by surgery. METHODS: Vestibular schwannomas from 18 patients were immunolabelled using a polyclonal antibody against VEGF, followed by light microscopy and blinded semiquantitation of VEGF expression. Fifteen patients had a well-defined tumor growth rate defined by repeated preoperative magnetic resonance imaging scans. RESULTS: All tumors showed expression of VEGF in the Schwann cell cytoplasm, with a more intense staining of the perinuclear region of some cells. The staining intensity varied from tumor to tumor, and semiquantitation revealed a significant correlation between VEGF expression and tumor growth rate, but not symptom duration or tumor size. CONCLUSION: VEGF is expressed in vestibular schwannomas and the level of expression correlates positively with tumor growth rate, but not with tumor size and symptom duration. We conclude that VEGF seems to be a factor involved in the growth of vestibular schwannomas.     

缺氧对鼻息肉上皮细胞表达血管内皮生长因子的影响

目的　通过上皮细胞对缺氧和炎性因子刺激的主动应答作用 ,探讨上皮细胞和缺氧对鼻息肉早期形成的影响。方法　将鼻息肉及下鼻甲的上皮细胞分别在常氧和缺氧状态下 ,以及不同炎性因子刺激条件下进行无血清原代上皮细胞的培养 ,采用原位杂交 ,酶联免疫吸附测定 (enzyme linkedimmunosorbentassay ,ELISA)的方法 ,用促红细胞生成素 (erythropoietin ,EPO)为缺氧标志 ,检测上皮细胞分泌合成的血管内皮生长因子 (vascularendothelialgrowthfactor ,VEGF)的线粒体RNA(mitochondriaRNA ,mRNA)和蛋白质水平的变化。结果　①缺氧条件下 ,EPO在来自于鼻息肉和下鼻甲的上皮细胞中明显表达 ,且两者无明显差异 ,表明EPO可作为组织缺氧标志 ;②上皮细胞合成的VEGFmRNA的能力在各种刺激下增加 ,而以缺氧条件下增加最为明显 (P <0 0 0 1) ,其中鼻息肉的合成能力要强于下鼻甲 (P <0 0 1) ;③VEGF的蛋白质表达水平在不同的炎性因子以及缺氧刺激下表达增加 (P <0 0 1) ,且随作用时间的延长而增强。其中以缺氧刺激下升高最为明显 (P <0 0 0 1)。鼻息肉的表达明显高于下鼻甲 (P <0 0 1)。结论　上皮细胞在缺氧时可主动合成VEGF。而这种中鼻道黏膜缺氧诱导的VEGF的产生和分泌是鼻息肉早期形成的重要机制。这也可能是鼻息     

Expression, localization, and significance of vascular permeability/vascular endothelial growth factor in nasal polyps

BACKGROUND: The exact etiologic mechanisms leading to the formation of nasal polyps have remained largely obscure. A key phenomenon of this specific type of chronic inflammatory disease in nasal respiratory mucosa is remarkable edema. Vascular permeability/vascular endothelial growth factor (VPF/VEGF) plays an important role in inducing angiogenesis and modulating capillary permeability. OBJECTIVE: To study the expression and localization of VPF/ VEGF as a putative key factor in nasal polyp development. METHODS: Specimens of nasal polyps (n = 12) were harvested during endonasal sinus surgery in patients with polypous chronic rhinosinusitis. Specimens of healthy nasal respiratory mucosa (n = 12) served as controls and were obtained from inferior turbinates of patients undergoing surgery for nasal obstruction without signs and symptoms of inflammatory disease. Frozen sections were immunohistochemically stained for VPF/VEGF and quantitatively analyzed, using computer-based image analysis. RESULTS: The expression of VPF/VEGF in specimens of nasal polyps was significantly stronger than in specimens of healthy nasal mucosa of controls. VPF/VEGF in polypous tissue was mainly localized in vascular endothelial cells, in basal membranes and perivascular spaces, and in epithelial cells. CONCLUSION: The markedly increased expression in nasal polyps as opposed to healthy nasal mucosa suggests that VPF/VEGF may play a significant role in both the formation of nasal polyps and in the induction of heavy tissue edema. This finding is discussed with respect to the differential expression of cyclooxygenase (COX) isoenzymes-1 and -2 (COX-1 and COX-2) in nasal polyps was significantly stronger than in specimens of healthy nasal mucosa of controls. VPF/VEGF in polypous tissue was mainly localized in vascular endothelial cells, in basal membranes and perivascular spaces, and in epithelial cells. Conclusion: The markedly increased expression in nasal polyps as opposed to healthy nasal mucosa suggests that VPF/VEGF may play a significant role in both the formation of nasal polyps and in the induction of heavy tissue edema. This finding is discussed with respect to the differential expression of cyclooxygenase (COX) isoenzymes-1 and -2 (COX-1 and COX-2) in nasal polyps.     

Vascular endothelial growth factor and children featuring nasal polyps

BACKGROUND: The aim of this study is to explore the expression of vascular endothelial growth factor within nasal polyps, and the implication of such expression as regards the development of nasal polyps amongst children. MATERIAL AND METHODS: Sixty children suffering from chronic rhinosinusitis were enrolled in this study. Amongst them, 30 patients featured rhinosinusitis with associated nasal polyps. A biopsy specimen was taken from the stalk or the base of the nasal polyp for nasal-polyp sufferers, and the ethmoid sinus for study participants who featured no nasal polyps. The primary lesions biopsied were immunohistochemically stained with a specific endothelial-cell marker and also stained for the presence of vascular endothelial growth factor. The specific level of vascular endothelial growth factor and the mean number of blood vessels present in a visual microscopic (biopsied-specimen) field were calculated under light microscopy (x400). RESULTS: The number of vascular endothelial growth factor-expressing cells for the nasal-polyp group and for the sinusitis group was, respectively, 20.8+/-4.0 and 11.5+/-3.4 per visual field. Correspondingly, the mean intra-polyp blood-vessel density for the nasal-polyp group and that for the control group was, respectively, 10.5+/-2.6 and 5.0+/-1.9 per visual field. The mean intra-polyp blood-vessel density and the number of vascular endothelial growth factor-expressing cells proved to be significantly greater amongst individuals from the nasal-polyp group than was the case for their analogs from the sinusitis group (P<0.01, for both). The presence of vascular endothelial growth factor was found to be distributed predominantly within the vascular endothelium and the mast cells of polyp tissue. In addition, the level of vascular endothelial growth-factor expression and the mean blood-vessel count per field correlated significantly for nasal-polyp tissue (P<0.001). Furthermore, the relative size of nasal polyps correlated significantly with the number of (intra-polyp) vascular endothelial-cell growth factor-expressing cells and the mean blood-vessel density (P<0.05, for both). CONCLUSION: The level of expression of vascular endothelial-cell growth factor (VEGF) and the mean blood-vessel density were shown to be significantly greater within nasal polyps than within corresponding sinusitis mucosa. Clinically, the expression of both of these parameters correlated well with the relative size of nasal polyps. Vascular endothelial growth factor participates in the formation of nasal polyps amongst children suffering from chronic rhinosinusitis (CRS).     

Hypoxia effects on vascular endothelial growth factor derived epithelial cells of nasal polyps]

OBJECTIVE: To understand the role of nasal mucous epithelial cells to hypoxia in early stage of nasal polyps(NP) formation. METHODS: Epithelial cells of NP and inferior turbinate (IT) were cultured without serum under normal oxygen and hypoxia, and stimulus of inflammatory cytokines. Erythropoietin (EPO) was regarded as hypoxia mark, and expression of vascular endothelial growth factor(VEGF) mRNA and protein derived from epithelial cells were detected respectively by in situ hybridization and ELISA. RESULTS: 1. Under hypoxia, EPO mRNA was expressed intensely in epithelial cells from NP and IT, and there was no significant difference between both of them. This result suggested that EPO might be regarded as a hypoxic mark. 2. The ability of producing VEGF mRNA increased with cytokines stimulation, especially under hypoxia. Protein level of VEGF from epithelial cells of NP and IT increased with cytokines stimulation, especially in hypoxia and was time-dependent. CONCLUSION: Epithelial cells actively produce vast VEGF under hypoxia. The VEGF induced by hypoxia of the mucosa in middle meatus is of importance in the formation of nasal polyps(NP) in early stage, which may be the major cause of NP formation in middle meatus.     

白细胞介素17与血管内皮生长因子在鼻息肉发病中的作用

鼻息肉是临床鼻科的常见病,其发生是一个多因素、多步骤、多种因子综合参与的复杂的病理生理过程。白细胞介素17是一种强大的前炎症细胞因子,血管内皮生长因子则是已知的最强的血管通透因子,近年来大量研究证实白细胞介素17与血管内皮生长因子在鼻息肉的发生、发展中扮演着重要的角色,且两者之间可能形成一个作用环,共同促进鼻息肉的发生与发展。     

三种促炎因子在鼻息肉及术后两周紧邻术区鼻黏膜的变化

目的 研究鼻息肉及鼻内镜术后2周紧邻术区鼻黏膜中血管细胞黏附分子（vascular cell adhesion molecule，VCAM）-1、嗜酸粒细胞亲合素（Eotaxin）及血管内皮生长因子（vascular endothelial growth factor，VEGF）的表达及相关性，探讨鼻息肉术后复发的可能机制。方法 应用链霉亲和素-过氧化物酶（SABC）免疫组化法检测30例鼻息肉及其中22例鼻内镜术后2周患者紧邻术区鼻黏膜的VCAM-1、eotaxin和VEGF的表达情况；HE染色光镜下观察组织结构、炎性细胞浸润情况。结果 ①HE染色可见鼻息肉组织嗜酸粒细胞大量浸润，术后则明显减少（t=2．891，P〈0．05）；②VCAM-1在鼻息肉手术前后均呈阳性表达，阳性面积差异无统计学意义（t=-2．051，P〉0．05），平均吸光度术后减弱（t=3．670，P=0．05）；Eotaxin手术前后阳性面积差异无统计学意义（t=0．739，P〉0．05），平均吸光度术后明显减弱（t=4．428，P〈0．05），Eotaxin术后腺体阳性率明显增加（t=-2．899，P〈0．05）；③VEGF阳性面积及平均吸光度手术前后表达差异均无统计学意义（t值分别为-0．037、0．825，P值均〉0．05）。结论 ①鼻息肉鼻内镜手术后嗜酸粒细胞数量明显减少，说明紧邻术区水肿状组织不同于鼻息肉。②VCAM-1、Eotaxin术后紧邻术区鼻黏膜阳性表达，说明Eotaxin有可能上调VCAM-1在血管内皮的表达，促进嗜酸粒细胞黏附于内皮细胞，穿内皮细胞问隙迁移到组织中，可能是息肉复发的基础。其中Eotaxin术后腺体阳性表达明显增加，推测其可能在鼻息肉复发早期发挥重要作用。③VEGF术后高表达，提示VEGF可促进术区血管增生及通透性增强，使局部组织增生、水肿，从而可能成为息肉复发过程中的重要因素之一。