Microvascular density and vascular endothelial growth factor expression in normal pituitary tissue and pituitary adenomas

Microvessel density (MVD) represents a measure of angiogenesis and may be used as an indicator of neoplastic aggressiveness. Vascular endothelial growth factor (VEGF) plays a pivotal role as angiogenic promoter by stimulating endothelial cell proliferation and migration and enhancing vascular permeability. The aim of this study was to investigate MVD and VEGF expression in human pituitary adenomas and normal pituitary gland tissues by immunohistochemistry, and to correlate data with clinical characteristics. Fragments from 46 pituitary adenomas (18 non-functioning, 12 ACTH-secreting, 12 GH-secreting, 4 PRL-secreting) and 19 specimens of normal anterior pituitary gland obtained at surgery were evaluated. MVD in normal anterior pituitary was significantly higher than in tumors (69.2 +/- 28.5 vs 29.3 +/- 19.7; p < 0.0001). Within adenomas, no difference was found in MVD when different histotype, size, sex, age, rate of recurrence or medical pre-surgical treatment were considered. The degree of vascularity was somewhat related only to clinical invasiveness, as evaluated by pre-surgical MRI grading (grade 0 p < 0.05 vs grade 1 and vs grade 2). No statistically significant difference in VEGF expression was found between normal tissue and adenomas and among tumors of different histotype (p = 0.3978). Size, sex, age, rate of recurrence and medical pre-surgical treatment did not influence VEGF expression. No correlation was found between MVD and VEGF expression. In conclusion, MVD was reduced in pituitary adenomas with respect to normal gland. VEGF expression is however well preserved in adenomas and this might contribute to adequate tumoral vascular supply with complex mechanisms other than endothelial cells proliferation.     

Oestradiol, vasoactive intestinal peptide and fibroblast growth factor in the growth of human pituitary tumour cells in vitro

The growth of two human prolactin-secreting cell lines developed in our laboratory has been investigated in response to a number of factors. Oestrogen stimulated the synthesis of DNA and protein and increased prolactin secretion. Dexamethasone had the opposite effect to oestrogen. In the presence of serum, epidermal growth factor (EGF) inhibited cell growth at concentrations of 5 ng/ml. Known secretagogues of prolactin (vasoactive intestinal peptide (VIP), TRH, bombesin and neurotensin) were investigated for their action on cell growth but only VIP had a stimulatory effect. Two preparations of fibroblast growth factor (FGF) were studied. One form, derived from bovine pituitary glands, stimulated human pituitary cell growth. In contrast, another FGF, of the basic type (rFGF), was inhibitory to cell growth, increasing the time for cell doubling from 30 to 72 h. This inhibitory effect of rFGF was modified but not abolished by serum, oestradiol, platelet-derived growth factor or EGF. We conclude that bovine pituitary contains at least two fibroblast growth factors, both of which stimulate fibroblast cell growth, but one stimulates and the other inhibits human pituitary tumour cell growth.     

Autocrine/paracrine action of pituitary vasoactive intestinal peptide on lactotroph hyperplasia induced by estrogen

Vasoactive intestinal polypeptide (VIP) content is increased in the hyperplastic pituitaries of estrogen (E)-treated rats, thus suggesting that this neuropeptide could mediate the E effect on lactotrophs. E also decreases pituitary TGF-beta1 content, an autocrine/paracrine inhibitor of lactotroph proliferation, and induces pituitary angiogenesis. To elucidate the role of VIP in this context, lactotroph hyperplasia was induced in female Fisher 344 rats by implanting sc pellets of diethylstilbestrol (DES). Twenty-five days later, the rats were treated with three different increasing doses of a VIP receptor antagonist or the vehicle for 5 d. DES treatment resulted in a marked increase of serum prolactin (PRL), pituitary PRL content, PRL mRNA expression, pituitary weight, and pituitary proliferating cell nuclear antigen. DES treatment also increased pituitary VIP content and VIP mRNA levels, but not in the hypothalamus and cerebral cortex. Simultaneously, DES treatment decreased the pituitary TGF-beta1 content and increased the pituitary content of vascular endothelial growth factor. VIP receptor antagonist partially reverted the effect of DES on serum PRL and pituitary PRL, proliferating cell nuclear antigen, TGF-beta1, and vascular endothelial growth factor contents, as well as on pituitary weight, in a dose-dependent relation. These data suggest that pituitary VIP mediates the effect of E on lactotroph hyperplasia, pituitary TGF-beta1, and angiogenesis.     

Increased pituitary vascular endothelial growth factor-a in dopaminergic D2 receptor knockout female mice

Vascular endothelial growth factor (VEGF)-A is an important angiogenic cytokine in cancer and pathological angiogenesis and has been related to the antiangiogenic activity of dopamine in endothelial cells. We investigated VEGF expression, localization, and function in pituitary hyperplasia of dopamine D2 receptor (D2R)-knockout female mice. Pituitaries from knockout mice showed increased protein and mRNA VEGF-A expression when compared with wild-type mice. In wild-type mice, prolonged treatment with the D2R antagonist, haloperidol, enhanced pituitary VEGF expression and prolactin release, suggesting that dopamine inhibits pituitary VEGF expression. VEGF expression was also increased in pituitary cells from knockout mice, even though these cells proliferated less in vitro when compared with wild-type cells, as determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium proliferation assay, proliferating cell nuclear antigen expression, and [(3)H]thymidine incorporation. In contrast to other animal models, estrogen did not increase pituitary VEGF protein and mRNA expression and lowered serum prolactin secretion in vivo and in vitro in both genotypes. VEGF (10 and 30 ng/ml) did not modify pituitary cell proliferation in either genotype and increased prolactin secretion in vitro in estrogen-pretreated cells of both genotypes. But conditioned media from D2R(-/-) cells enhanced human umbilical vein cell proliferation, and this effect could be partially inhibited by an anti-VEGF antiserum. Finally, using dual-labeling immunofluorescence and confocal laser microscopy, we found that in the hyperplastic pituitaries, VEGF-A was mostly present in follicle-stellate cells. In conclusion, pituitary VEGF expression is under dopaminergic control, and even though VEGF does not promote pituitary cellular proliferation in vitro, it may be critical for pituitary angiogenesis through paracrine actions in the D2R knockout female mice.     

Synovial expression of vasoactive intestinal peptide in polymyalgia rheumatica

OBJECTIVE: Polymyalgia rheumatica (PMR) is an inflammatory disease that typically affects elderly people. Its clinical hallmark is the severity of pain in the shoulder and pelvic girdle. Mild to moderate synovitis and/or bursitis of the joints involved has been described. Neuropeptides are involved in nociception and modulation of inflammatory reaction. To evaluate whether neuropeptides have a role in PMR pathophysiology, we studied the expression of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and somatostatin (SOM) in shoulder synovial tissues of PMR patients. METHODS: Synovial expression of neuropeptides was investigated by immunohistochemical analysis, in two groups of PMR patients: the first one at the onset of disease and the second one after corticosteroid treatment, and in other joint diseases, rheumatoid arthritis (RA) and osteoarthritis (OA). RESULTS: The only significant expression of VIP was found in PMR and, to a lesser extent, in RA synovial tissue. In PMR, we observed VIP immunostaining both in the lining layer and in the sublining area. In patients on corticosteroid treatment VIP lining layer expression was not significantly different while VIP positive cells in the sublining area were almost absent. CONCLUSION: Local VIP production in PMR synovial tissue might contribute to the typical musculoskeletal discomfort and it may have a role in the immunomodulation of synovial inflammation.     

血管内皮生长因子及其受体在肺气肿患者肺组织中的表达

目的探讨血管内皮生长因子(VEGF)及其受体2(VEGF受体2/KDR)在肺气肿患者肺组织中的表达及其与肺气肿的相关性。方法取35例行肺叶切除术患者[A组(吸烟伴肺气肿组)16例,B组(不吸烟肺功能正常组)14例,C组(吸烟但肺功能正常组)5例]的外周肺组织标本,ELISA法检测肺组织匀浆中VEGF的含量,免疫组化法检测KDR蛋白表达,RT PCR检测VEGF和KDRmRNA水平,TUNEL法检测肺泡隔细胞的凋亡。结果A组患者肺组织VEGF、KDR表达均低于B组(P<0.01),肺泡隔细胞凋亡率高于B组(P<0.01)。C组与B组相比,VEGF及KDR表达差异无统计学意义(P>0.05)。结论VEGF及KDR水平减少与肺泡隔细胞凋亡的增加可能与肺气肿的发生相关。     

Stimulation of growth hormone release by vasoactive intestinal peptide and peptide PHI in rat anterior pituitary reaggregates. Permissive action of a glucocorticoid and inhibition by thyrotropin-releasing hormone

In superfused rat anterior pituitary cell reaggregates, cultured for 5 days in serum-free defined medium, vasoactive intestinal peptide (VIP) concentration-dependently stimulated prolactin (Prl) release but had only a marginal effect on growth hormone (GH) release. When reaggregates were cultured in the presence of 80 nM dexamethasone (Dex) VIP strongly stimulated GH release from a concentration as low as 0.1 nM. VIP did not stimulate LH release. Peptide PHI also stimulated GH release but thyrotropin-releasing hormone (TRH) or angiotensin II did not. In fact, TRH slightly but transiently inhibited basal GH release and strongly inhibited VIP-stimulated GH release. GH-releasing factor (GRF) stimulated GH more potently and with higher intrinsic activity than VIP but GRF did not increase Prl release. The present data indicate that under defined hormonal conditions VIP and PHI are capable of stimulating GH release and that TRH can antagonize this effect by a direct action on the pituitary.     

大肠癌组织中血管内皮生长因子的表达及意义

目的 探讨血管内皮生长因子（ＶＥＧＦ）在大肠癌组织中的表达及其与大砀癌发展的关系。方法 应用名单组织化学ＬＳＡＢ法检测５２你人大肠癌组织的ＶＥＧＦ表达,分析ＶＥＧＦ与大肠癌组织类类型、分化程度、Ｄｕｋｅｓ分期及淋巴结转移毕率随关大肠癌Ｋｕｋｅｓ分期的进展而增加,且Ｄｕｋｅｓ Ｃ期的ＶＥＧＦ表达率与ＤｕｋｅｓＡ期相比有显著性差异（Ｐ〈０．０５）,ＶＥＧＦ在有淋巴结转移组的４０．００％（Ｐ〈０．０１）     

Transforming growth factor-beta stimulates vascular endothelial growth factor production by folliculostellate pituitary cells

TGF-beta isoforms are expressed in the anterior pituitary and modulate the growth and function of endocrine pituitary cells. Recently, TGF-beta has been shown to stimulate growth and basic fibroblast growth factor secretion in nonendocrine folliculostellate (FS) pituitary cells. We therefore studied whether the production of FS cell-derived vascular endothelial growth factor (VEGF), the most important regulator of vascular permeability and angiogenesis, is affected by TGF-beta. We observed by RT-PCR that TtT/GF cells, which are FS mouse pituitary tumor cells, synthesize TGF-beta1, -beta2, and -beta3. They also express TGF-beta receptors types 1 and 2, as well as Smad2, Smad3, and Smad4 proteins, which are essential for TGF-betabinding and signaling. Stimulation of TtT/GF cells with either TGF-beta1 or TGF-beta3 induced a rapid translocation of Smad2 into the cell nuclei. Both TGF-beta isoforms dose dependently stimulated VEGF production in TtT/GF cells, but not in lactosomatotroph GH3 cells. Time-course studies and suppression of TGF-beta-induced VEGF production by cycloheximide suggest that TGF-beta induces de novo synthesis of VEGF in folliculostellate cells, which is completely blocked by dexamethasone. In primary rat pituitary cell cultures, TGF-beta1 and -beta3 stimulated VEGF production. TGF-beta stimulation of VEGF production by folliculostellate cells could modulate intrapituitary vascular permeability and integrity as well as angiogenesis in an auto-/paracrine manner.     

大肠癌血管内皮生长因子的表达及其意义

目的：探讨血管内皮生长因子（VEGF）mRNA在大肠癌和癌周组织中的表达及其与临床特征之间的关系,为在分子水平干预肿瘤血管形成,预防大肠癌复发和转移打下基础。方法：采用逆转录－聚合酶链反应（RT－PCR）检测方法,对68例大肠癌手术标本癌和癌周组织中VEGF mRNA的表达水平进行了相对定量研究。结果：肿瘤组织中VEGF mRNA的表达率为67．6％（46／68）,癌周组织表达率为32．4％（22／68）;肿瘤组织中VEGF mRNA表达水平在浆膜浸润组,淋巴结转移,远处转移和Dukes D期组分别显著高于未侵及浆膜组,无淋巴结转移组,无远处转移和Dukes A,B,C期组;肿瘤组织中VEGF mRNA表达水平在肿瘤直径大的大肠癌组（＞5cm)与大小肠癌组（≤5cm)以及不同组织学分组组之间相比差异无显著性。结论：VEGF在大肠癌浸润和转移过程中发挥重要作用,肿瘤血管形成与大肠癌浸润和转移关系密切。     

布地奈德/福莫特罗对支气管哮喘患者血管内皮生长因子及其受体1表达及气道重塑的调控作用

目的支气管哮喘(简称哮喘)是一种慢性气道炎症疾病,伴随气道高反应性、可逆性气流阻塞和气道重塑。血管生成和微血管重塑在气道慢性炎症过程中可能起到重要的作用。血管内皮生长因子(vascular endothelial growth factor,VEGF)是一种促血管生成因子,其生理作用包括促进内皮细胞存活、增殖和迁移。本研究通过检测哮喘患者气道VEGF和VEGF受体1(VEGFR1)的表达,探讨VEGF和哮喘患者气道重塑的关系以及布地奈德/福莫特罗对哮喘患者气道重塑的调控作用。方法支气管组织来源于2006年4月至11月四川大学华西医院经纤维支气管镜行组织活检。23例为中度哮喘患者,20例为对照组。哮喘患者给予规律吸入布地奈德/福莫特罗4.5/160μg,2次/d,持续半年。VEGF和VEGFR1通过免疫组织化学进行检测。AB-PAS和MassonTrichrome染色用于评估气道重塑程度。结果两组之间年龄和性别差异无统计学意义。而两组之间用力肺活量占预计值%,第一秒用力呼气容积占预计值%,PC20,V75占预计值%,V50占预计值%和V25占预计值%的差异有统计学意义。哮喘组患者气道黏液腺增生、平滑肌增厚、上皮下纤维化以及新生血管增加。与对照组比较,VEGF和VEGFR1阳染细胞数目增多,表达增加。VEGF和VEGFR1表达增加与哮喘患者的气道重塑、气流阻塞和气道高反应性呈正相关。规律吸入布地奈德/福莫特罗6个月后,哮喘患者VEGF和VEGFR1表达减少,气道重塑减轻。结论伴随哮喘患者气道血管生成增多和气道重塑,VEGF和VEGFR1表达增加。规律吸入布地奈德/福莫特罗可以通过减少VEGF和VEGFR1表达而减轻哮喘患者气道重塑。阻断VEGF和VEGFR1可能是治疗哮喘的新策略。     

Neonatal androgenization increases vasoactive intestinal peptide levels in rat anterior pituitary: possible involvement of vasoactive intestinal peptide in the neonatal androgenization-induced hyperprolactinemia.

Accumulating evidence suggests that vasoactive intestinal peptide (VIP) may be a physiological PRL-releasing factor. In the present study, we examined a possible involvement of VIP in the neonatal androgenization (NA)-induced hyperprolactinemia. Twenty-four hours after birth, newborn female rats were injected sc with 1,000 micrograms of testosterone (NA) or with oil vehicle only (control). Both groups were sacrificed at 8 weeks of age. Compared to controls, NA rats showed significantly higher plasma PRL levels (7.3 fold), anterior pituitary (AP) PRL content (2.1 fold) and plasma estradiol levels (2.1 fold). AP VIP content was extremely higher (61 fold) in NA rats than in controls. However, NA did not affect VIP content in the suprachiasmatic nucleus, paraventricular nucleus or median eminence. These results suggest that the NA-induced hyperprolactinemia may be mediated, at least in part, by paracrine and/or autocrine effects of the increased AP VIP on PRL secretion. However, since the potentiation by NA of the AP VIP content was extremely marked compared to those of the other parameters, the possibility was also raised that the increased AP VIP may be involved in other endocrine and/or nonendocrine events occurring in the AP.     

非小细胞肺癌中肝素酶基因与血管内皮生长因子表达的研究

目的　探讨肝素酶基因及血管内皮生长因子 (VEGF)在非小细胞肺癌 (NSCLC)中的表达及其临床病理学意义。方法　选取 85例肺部手术标本 ,所有标本分成两份 ,1份用于逆转录PCR检测肝素酶mRNA ,1份用于免疫组化检测VEGF。结果　 (1)肝素酶mRNA及VEGF在NSCLC中表达率均高于良性病变肺组织 (P <0 0 5 )。 (2 )肝素酶mRNA表达率在淋巴结转移组、远处转移组、Ⅲ期 +Ⅳ期组、低分化组、腺癌组、肿瘤最大径≥ 5cm组分别高于无淋巴结转移组、无远处转移组、Ⅰ期 +Ⅱ期组、高中分化组、鳞癌组、最大径 <5cm组 (P <0 0 5 )。 (3)VEGF表达率在淋巴结转移组、远处转移组、Ⅲ期 +Ⅳ期组分别高于无淋巴结转移组、无远处转移组、Ⅰ期 +Ⅱ期组 (P <0 0 5 )。 (4 )NSCLC中肝素酶mRNA与VEGF表达无相关性 (P >0 0 5 )。结论　肝素酶与VEGF参与了NSCLC的侵袭转移过程 ,可作为判断NSCLC转移潜力指标 ;肝素酶与VEGF通过互不依赖的机制促进NSCLC的侵袭与转移 ,二者联合检测将有利于提高判断NSCLC转移潜力的敏感性及特异性。     

Angiopoietin and vascular endothelial growth factor expression in colorectal disease models

AIM:To investigate angiopoietin(Ang) and vascular endothelial growth factor(VEGF) expression in rats with ulcerative colitis(UC) and colorectal cancer(CRC).METHODS:Dysplasia and cancer were investigatedin rats that received three cycles of 3.5% dextran sulfate sodium(DSS) in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with 20 mg/kg 1,2-dimethylhydrazine(DMH)(CRC group).Colitis was investigated in rats that received three cycles of 3.5% DSS in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with saline(UC group).Rats without DSS or DMH treatment served as controls.Expression of the tyrosine kinase with immunoglobulinlike and EGF-like domains(Tie)-2 and its ligands,Ang-1 and Ang-2,as well as VEGF were evaluated in the colorectum by Western blotting.RESULTS:Compared with rats in the control group,rats in the CRC and UC groups developed the symptoms of acute colitis with diarrhea,rectal bleeding,wasting,and loss of body weight(P < 0.05).In addition,the mean length of colorectum of CRC and UC rats was significantly shorter than that of control rats(8.29 ± 0.21 and 8.31 ± 0.86,respectively,vs 12.34 ± 0.12 cm; P < 0.05).Furthermore,rats in the CRC group,but not in the UC or control groups,developed multiple tumors in the colorectal region.Western blot analysis revealed that rats in the CRC and UC groups had markedly increased protein levels of Ang-1,Ang-2,Tie-2,and VEGF in the colorectum compared to rats in the control group.CONCLUSION:Increased expression of Ang-1,Ang-2,Tie-2,and VEGF in ulcerative colitis-derived colorectal cancer might lead to chronic colitis and pathologic angiogenesis in rats.