Astragalus polysaccharides exert protective effects in newborn rats with bronchopulmonary dysplasia by upregulating the expression of EGFL7 in lung tissue.

The aim of this study was to explore the effects of Astragalus polysaccharides (APS) on the mRNA expression of epidermal growth factor-like domain 7 (EGFL7) in lung tissue in newborn rats with bronchopulmonary dysplasia (BPD). For this purpose, a total of 96 newborn SD rats were randomly divided into 4 groups (n=24): the control group, air room plus APS group, BPD group and the APS group (20 mg/kg/day). Lung tissues were obtained on days 4, 10 and 14 after birth. Morphological changes were observed and the protein and mRNA expression levels of EGFL7, Bax and Bcl-2 were determined. The rats in the BPD group (BPD induced by hyperoxia) presented with an arrest in alveolar and vascular development and low mRNA and protein expression levels of of EGFL7, Bcl-2 and high levels of Bax compared with the rats in the control group. However, lung damage in the APS intervention group was attenuated compared with the BPD group. The protein and mRNA expression levels of EGFL7 and Bcl-2 were also increased and the level of Bax was decreased in the APS intervention group (P<0.01) compared with the BPD model group after birth on days 4, 10 and 14. Our data demonstrate that APS reduce airway remodeling and alveolar damage by upregulating the expression of EGFL7 and exert protective effects against BPD in neonatal rats. Thus, APS may have potential for use as a therapeutic strategy for BPD.

VE-statin, an endothelial repressor of smooth muscle cell migration.

The recruitment and proliferation of smooth muscle cells and pericytes are two key events for the stabilization of newly formed capillaries during angiogenesis and, when out of control in the adult, are the main causes of arteriosclerosis. We have identified a novel gene, named VE-statin for vascular endothelial-statin, which is expressed specifically by endothelial cells of the developing mouse embryo and in the adult, and in early endothelial progenitors. The mouse and human VE-statin genes have been located on chromosome 2 and 9, respectively, they span >10 kbp and are transcribed in two major variants arising from independent initiation sites. The VE-statin transcripts code for a unique protein of 30 kDa that contains a signal peptide and two epidermal growth factor (EGF)-like modules. VE-statin is found in the cellular endoplasmic reticulum and secreted in the cell supernatant. Secreted VE-statin inhibits platelet-derived growth factor (PDGF)-BB-induced smooth muscle cell migration, but has no effects on endothelial cell migration. VE-statin is the first identified inhibitor of mural cell migration specifically produced by endothelial cells.

The agonist of the protease-activated receptor-1 (PAR) but not PAR3 mimics thrombin-induced vascular endothelial growth factor release in human smooth muscle cells.

Thrombin, a serine protease generated by the activation of the blood coagulation cascade following vessel injury, induces vascular endothelial growth factor-(VEGF) release. However, the molecular mechanism of thrombin-induced VEGF release is largely unknown. Anagonist of protease-activated receptor-i (PARI), SFLL-RNPNDKYEPF, mimicked thrombin-induced VEGF release in human vascular smooth muscle (HVSM) cells, as determined by enzyme-linked immunosorbent assay, reverse transcriptase-polymerase chain reaction, and Northern blotting. In contrast, the agonist of PAR3, TFR- GAP, did not affect VEGF release or expression. SFLL-RNPNDKYEPF, but not TFRGAP, up-regulated [Ca2-]i.Moreover, the calcium ionophone A23187 was found to trigger VEGF release in HVSM cells. Thrombin-inducedVEGF release was blocked by anti-thrombin, heparin, a synthetic thrombin receptor inhibitor E5510, the calcium chelator BAPTA, the protein kinase C inhibitor calphostin C, and the MEK1/2 inhibitor U0126. Thus, our data show that thrombin caused VEGF release via PARI activation in a manner dependent on [Ca2+]i and p44/42 downstream from the receptor activation.

Comparison of cardioprotective effects using ramipril and DanShen for the treatment of acute myocardial infarction in rats.

In the present study, we compared cardioprotective effects of DanShen (an extract from Salvia miltiorrhiza) and the angiotensin-converting enzyme inhibitor, ramipril, in rats. With both treatment regimens, DanShen- and ramipril similar effects were observed: (1) a higher survival rate, (2) a significant reduction of infarct size, (3) significantly lower ratios of heart weight to the body weight as well as the left and right ventricular weights to body weight. DanShen showed some unique effects in the following aspects: (1) higher activities of antioxidant defense enzymes such as superoxide dismutase (SOD), catalase (CAT), glutatione perioxidase (GSH-Px) and glutathione S-transferase (GST) in the liver of rats with acute myocardial infarction (AMI), (2) lower myocardial and hepatic TBARS values; (3) augmented VEGF mRNA expressions in the non-ischemic parts of rat hearts with AMI. These results were consistent with the findings of a slight increase in myocardial capillary density and the special distribution pattern of coronary blood vessels in DanShen-treated rats.

Anti-angiogenic potential of Gleditsia sinensis fruit extract.

Blood supply plays a crucial role in solid tumour development and leukaemogenesis. It has been suggested that blocking of angiogenesis could be possible in cancer therapy. We have demonstrated the antiproliferative activity of Gleditsia sinensis fruit extract (GSE) on various human solid tumour cancer cell lines as well as leukaemia cell lines and primary cultured leukaemia cells obtained from leukaemia patients. However, the antiangiogenic potential of GSE has not been demonstrated. Here we demonstrated that GSE could reduce vascular endothelial growth factor (VEGF) mRNA expression in dose- and time course-dependently in MDA-MB231 breast cancer and HepG2 hepatoblastoma cell lines as measured by reverse transcriptase polymerase chain reaction. Enzyme-linked immunosorbent assay further showed that GSE could reduce the VEGF secretion from various cancer cell lines including MDA-MB231, HepG2, HL-60 (acute promyelocytic leukaemia) and eleven primary cultured leukaemia cells obtained from acute myelogenous leukaemia patients. In vivo chick chorioallantoic membrane assay illustrated that GSE could reduce the angiogenic activity of basic fibroblast growth factor. Taken together, the information suggested that GSE could be potentially used as an angiogenic inhibitor in both solid tumour and leukaemia therapy.

Effect of ascorbate on the activity of hypoxia-inducible factor in cancer cells.

Hypoxia-inducible factor (HIF) plays an important role in determining patterns of gene expression in cancer. HIF is down-regulated in oxygenated cells by a series of Fe (II) and 2-oxoglutarate dependent dioxygenases that hydroxylate specific residues in the regulatory HIF-alpha subunits. Because these enzymes require ascorbate for activity in vitro we analyzed the effects of ascorbate on HIF in human cancer cell lines. Ascorbate at physiological concentrations (25 micro M) strikingly suppressed HIF-1alpha protein levels and HIF transcriptional targets, particularly when the system was oncogenically activated in normoxic cells. Similar results were obtained with iron supplementation. These results indicate that both ascorbate and iron availability have major effects on HIF, and imply that the system is commonly regulated by limiting hydroxylase activity under normoxic tissue culture conditions.

Crude extract of Salvia miltiorrhiza and salvianolic acid B enhance in vitro angiogenesis in murine SVR endothelial cell line.

Salvia miltiorrhiza (SM) has been used clinically in Asian countries to improve the microcirculation in the human body. Although a pure compound extracted from SM, salvianolic acid B (Sal B), has been reported to be effective against fibrosis and ischemia-reperfusion injury, possibly through its anti-lipid peroxidation action, the effect of SM on angiogenesis remains unclear. It is our interest to investigate the role of SM on the regulation of the angiogenic process. By using the SVR endothelial cell line as an in vitro system, the effects of Sal B on the gene expression of vascular endothelial growth factor (VEGF) and its receptors VEGF-R1, VEGF-R2 were evaluated by morphology, differentiation assay, reverse-transcribed polymerase chain reaction (RT-PCR) and Western blot analysis. The results showed that both the crude extract of SM and the pure compound Sal B had enhancing effects on cell growth and differentiation. The gene expression of matrix metalloproteinase-2 (MMP-2) was up-regulated after Sal B treatment for 2 h, while VEGF and VEGF-R2 gene expression were up-regulated 40 min after Sal B treatment. We conclude that the crude extract of SM and Sal B enhance angiogenic processes on SVR cells through up-regulation of VEGF and VEGF receptors genes.

Malignant mesothelioma growth inhibition by agents that target the VEGF and VEGF-C autocrine loops.

Malignant mesothelioma (MM) is a locally aggressive tumor that originates from the mesothelial cells of the pleural and sometimes peritoneal surface. Conventional treatments for MM, consisting of chemotherapy or surgery give little survival benefit to patients, who generally die within 1 year of diagnosis. Hence, there is an urgent need for the development of alternative therapies. Vascular endothelial growth factor (VEGF) is an autocrine growth factor for MM. The closely related molecule, VEGF-C, is also implicated in malignant mesothelioma growth. VEGF-C and its cognate receptor VEGFR-3 are co-expressed in mesothelioma cell lines. A functional VEGF-C autocrine growth loop was demonstrated in mesothelioma cells by targeting VEGF-C expression and binding to VEGFR-3. The ability of novel agents that reduce the levels of VEGF and VEGF-C to inhibit mesothelioma cell growth in vitro was assessed. Antisense oligonucleotide (ODN) complementary to VEGF that inhibited VEGF and VEGF-C expression simultaneously specifically inhibited mesothelioma cell growth. Similarly, antibodies to VEGF receptor (VEGFR-2) and VEGF-C receptor (VEGFR-3) were synergistic in inhibiting mesothelioma cell growth. In addition, a diphtheria toxin-VEGF fusion protein (DT-VEGF), which is toxic to cells that express VEGF receptors was very effective in inhibiting mesothelioma cell growth in vitro. These results indicate that targeting VEGF and VEGF-C simultaneously may be an effective therapeutic approach for malignant mesothelioma.

Inhibitory effects of Ginkgo biloba extract on vascular endothelial growth factor in rat aortic endothelial cells.

AIM: To study the protective effects of Ginkgo biloba extract (GbE) against rat aortic endothelial cells (RAEC) damage induced by lysophosphatidylcholine (LPC). METHODS: Cell injury were determined by MTT assay and LDH release. Vascular endothelial growth factor (VEGF) protein production from RAEC was determined by enzyme-linked immunosorbent assay (ELISA). VEGF mRNA expression was examined by in situ hybridization and dot blot. RESULTS: GbE 0.01-1 microg/L prevented LPC-induced injury in cultured RAEC in a concentration-dependent manner. Cultured RAEC could express VEGF protein and VEGF mRNA was induced by LPC 5 mg/L. GbE could inhibit the expression of VEGF protein and VEGF mRNA in co-cultured RAEC with LPC. CONCLUSION: LPC could induce a strong expression of VEGF in RAEC. GbE could protect RAEC against the LPC-induced damage and downregulate VEGF protein and VEGF mRNA expression in cultured RAEC.

Dermal wound healing properties of redox-active grape seed proanthocyanidins.

Angiogenesis plays a central role in wound healing. Among many known growth factors, vascular endothelial growth factor (VEGF) is believed to be the most prevalent, efficacious, and long-term signal that is known to stimulate angiogenesis in wounds. The wound site is rich in oxidants, such as hydrogen peroxide, mostly contributed by neutrophils and macrophages. We proposed that oxidants in the wound microenvironment support the repair process. Proanthocyanidins or condensed tannins are a group of biologically active polyphenolic bioflavonoids that are synthesized by many plants. Previously we have reported that a grape seed proanthycyanidin extract containing 5000 ppm resveratrol (GSPE) potently upregulates oxidant and tumor necrosis factor-alpha inducible VEGF expression in human keratinocytes (Free Radic. Biol. Med. 31:38-42, 2001). Our current objective was to follow up on that finding and test whether GSPE influences dermal wound healing in vivo. First, using a VEGF promoter-driven luciferase reporter construct we observed that the potentiating effect of GSPE on inducible VEGF expression is at the transcriptional level. The reporter assay showed that GSPE alone is able to drive VEGF transcription. Next, two dermal excisional wounds were inflicted on the back of mice and the wounds were left to heal by secondary intention. Topical application of GSPE accelerated wound contraction and closure. GSPE treatment was associated with a more well-defined hyperproliferative epithelial region, higher cell density, enhanced deposition of connective tissue, and improved histological architecture. GSPE treatment also increased VEGF and tenascin expression in the wound edge tissue. Tissue glutathione oxidation and 4-hydroxynonenal immunostaining results supported that GSPE application enhanced the oxidizing environment at the wound site. Oxidants are known to promote both VEGF as well as tenascin expression. In summary, our current study provides firm evidence to support that topical application of GSPE represents a feasible and productive approach to support dermal wound healing.

Short-term insulin treatment and aortic expressions of IGF-1 receptor and VEGF mRNA in diabetic rats.

We investigated the relationship between the changes in vascular responsiveness and growth factor mRNA expressions induced by 1-wk treatment with high-dose insulin in control and established streptozotocin (STZ)-induced diabetes. Aortas from diabetic rats, but not those from insulin-treated diabetic rats, showed impaired endothelium-dependent relaxation in response to ACh (vs. untreated controls). The ACh-induced nitrite plus nitrate (NOx) level showed no significant difference between controls and diabetics. Insulin treatment increased NOx only in diabetics. In diabetics, insulin treatment significantly increased the aortic expressions of endothelial nitric oxide synthase (eNOS) mRNA and VEGF mRNA. The expression of IGF-1 mRNA was unaffected by diabetes or by insulin treatment. In contrast, the mRNA for the aortic IGF-1 receptor was increased in diabetics and further increased in insulin-treated diabetics. In aortic strips from age-matched control rats, IGF-1 caused a concentration-dependent relaxation. This relaxation was significantly stronger in strips from STZ-induced diabetic rats. These results suggest that in STZ-diabetic rats, short-term insulin treatment can ameliorate endothelial dysfunction by inducing overexpression of eNOS and/or VEGF mRNAs possibly via IGF-1 receptors. These receptors were increased in diabetes, perhaps as result of insulin deficiency.

Omega-3 fatty acid supplementation reduces tumor growth and vascular endothelial growth factor expression in a model of progressive non-metastasizing malignancy.

BACKGROUND: Omega-3 fatty acids, the principal component of fish oil, have been demonstrated to have antiinflammatory properties. The role of eicosapentaenoic acid (EPA) supplementation for cancer patients is currently under investigation; however, the mechanisms of EPA activity have not been defined. The purpose of this study was to characterize tumor-specific and treatment-specific effects of supplemental dietary EPA in an animal model of progressive malignancy. METHODS: Fischer 344 rats (200-250 g) underwent flank implantation of the methycholanthrene (MCA)-induced fibrosarcoma on day 0. Rats were randomly divided into 3 treatment groups on day 13: EPA (1 mL, 5.0 g/kg per day) + 10 IU vitamin E; corn oil (1 mL) + 10 IU vitamin E, and saline (1 mL) + 10 IU vitamin E (vitamin E was used to prevent fatty acid oxidation). On day 14, gavage feeding was started and was continued through day 28. The animals were killed on day 29, and the tumors were removed. The tumors were weighed and divided by the tumor-free carcass weight to obtain percentage of tumor volume, and the livers were flash frozen. Vascular endothelial growth factor-alpha (VEGF-alpha) and cyclo-oxygenase 2 (COX-2) mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: EPA rats had significant reductions in tumor volume compared with isocaloric corn oil and control saline animals (25%, p < .01 and 33%, p < .01, respectively). Rats receiving EPA demonstrated decreased VEGF-alpha mRNA levels (0.023 +/- 0 0.001) compared with those receiving corn oil (0.129 +/- 0.047) or saline (0.150 +/- 0.026; p < .05). CONCLUSIONS: These data demonstrate that EPA supplementation inhibits tumor growth, potentially through alterations in the expression of the pro-angiogenic VEGF-alpha. The mechanism(s) of EPA as an inhibitor of tumor-related angiogenic growth factors may be associated with COX-2 enzyme fatty acid metabolism and merits further study.

Green tea inhibits vascular endothelial growth factor (VEGF) induction in human breast cancer cells.

Investigators have shown that green tea and its main catechin epigallocatechin-3 gallate (EGCG) may decrease the risk of cancer. Our previous study showed that green tea extract (GTE) as well as its individual catechin components inhibited MDA-MB231 breast cancer cell and human umbilical vein endothelial cell (HUVEC) proliferation. Further, GTE suppressed breast cancer xenograft size and decreased the tumor vessel density in vivo. In the current study, we investigated the effect of GTE on the major angiogenic factor vascular endothelial growth factor (VEGF) in an in vitro experiment. GTE or EGCG (40 mg/L) significantly decreased the levels of the VEGF peptide secreted into conditioned media. This occurred in both HUVEC and human breast cancer cells and the effect was dose dependent. Furthermore, GTE and EGCG decreased the RNA levels of VEGF in MDA-MB231 cells. This inhibition occurred at the transcriptional regulation level and was accompanied by a significant decrease in VEGF promoter activity. We also showed that GTE decreased c-fos and c-jun RNA transcripts, suggesting that activator protein (AP)-1-responsive regions present in the human VEGF promoter may be involved in the inhibitory effect of GTE. Furthermore, GTE suppressed the expression of protein kinase C, another VEGF transcription modulator, in breast cancer cells. Inhibition of VEGF transcription appeared to be one of the molecular mechanism(s) involved in the antiangiogenic effects of green tea, which may contribute to its potential use for breast cancer treatment and/or prevention.

Hyperbaric oxygen selectively induces angiopoietin-2 in human umbilical vein endothelial cells.

One of the biological effects of hyperbaric oxygen (HBO) therapy in enhancing ischemia-related wound healing is the induction of angiogenesis. To elucidate the mechanism(s) underlying the HBO-induced angiogenesis, we studied the expression of several angiogenesis-related genes in human umbilical vein endothelial cells exposed to HBO. Western blot analyses showed that HBO enhanced the expression of angiopoietin-2 (Ang2) with no effect on the expression of Tie2, angiopoietin-1, and VEGF. The induction of Ang2 was further confirmed by immunohistochemistry, quantitative PCR, and Northern blot analyses. Inhibition of endothelial nitric oxide synthase blocked the HBO-induced Ang2 expression, but failed to block hypoxia-induced Ang2 expression. These data indicated that HBO-induced Ang2 expression may be through transcriptional stimulation, and requires the nitric oxide signaling pathway, which may play an important role in HBO-induced angiogenesis.

Anti-angiogenic action of hyperthermia by suppressing gene expression and production of tumour-derived vascular endothelial growth factor in vivo and in vitro.

Vascular endothelial growth factor is an important angiogenic factor for tumour progression because it increases endothelial-cell proliferation and remodels extracellular matrix in blood vessels. We demonstrated that hyperthermia at 42 degrees C, termed heat shock, suppressed the gene expression and production of vascular endothelial growth factor in human fibrosarcoma HT-1080 cells and inhibited its in vitro angiogenic action on human umbilical vein endothelial cells. The gene expression of alternative splicing variants for vascular endothelial growth factor, VEGF121, VEGF165 and VEGF189, was constitutively detected in HT-1080 cells, but the VEGF189 transcript was less abundant than VEGF121 and VEGF165. When HT-1080 cells were treated with heat shock at 42 degrees C for 4 h and then maintained at 37 degrees C for another 24 h, the gene expression of all vascular endothelial growth factor variants was suppressed. In addition, HT-1080 cells were found to produce abundant VEGF165, but much less VEGF121, both of which were inhibited by heat shock. Furthermore, the level of vascular endothelial growth factor in sera from six cancer patients was significantly diminished 2-3 weeks after completion of whole-body hyperthermia at 42 degrees C (49.9+/-36.5 pg x ml(-1), P<0.01) as compared with that prior to the treatment (177.0+/-77.5 pg x ml(-1)). On the other hand, HT-1080 cell-conditioned medium showed vascular endothelial growth factor-dependent cell proliferative activity and the augmentation of pro-matrix metalloproteinase-1 production in human umbilical vein endothelial cells. The augmentation of endothelial-cell proliferation and pro-matrix metalloproteinase-1 production was poor when human umbilical vein endothelial cells were treated with conditioned medium from heat-shocked HT-1080 cells. These results suggest that hyperthermia acts as an anti-angiogenic strategy by suppressing the expression of tumour-derived vascular endothelial growth factor production and thereby inhibiting endothelial-cell proliferation and extracellular matrix remodelling in blood vessels.

Inhibition of vascular endothelial growth factor expression and production by triptolide.

Triptolide, the major component of the diterpenoids of the Chinese herb Tripterygium wilfordii Hook f. (Celastraceae), inhibited vascular endothelial growth factor expression and secretion in endothelial cells treated by 12-O-tetradecanoylphorbol 13-acetate dose-dependently. This effect may be one of the mechanisms underlying the therapeutic effects of triptolide on rheumatoid arthritis.

Reactive oxygen species accelerate production of vascular endothelial growth factor by advanced glycation end products in RAW264.7 mouse macrophages.

Advanced glycation end products (AGEs) are believed to play an important role in the development of angiopathy in diabetes mellitus. Previous reports suggested a correlation between accumulation of AGEs and production of vascular endothelial growth factor (VEGF) in human diabetic retina. However, the mechanisms involved were not revealed. In this study, we investigated the transcriptional regulation of the expression of vascular endothelial growth factor (VEGF) by AGEs, and possible involvement of reactive oxygen species (ROS) in the induction. We employed an AGE of bovine serum albumin (BSA) prepared by an incubation of BSA with D-glucose for 40 weeks and N(epsilon)-(carboxymethyl)lysine (CML), a major AGE. The expression of VEGF was induced by CML-BSA in RAW264.7 mouse macrophage-like cells. CML-BSA stimulated the DNA-binding activity of activator protein-1 (AP-1). Promoter assay showed that the induction of VEGF was dependent on AP-1. The activity of Ras/Raf-1/MEK/ERK1/2 was involved in the CML-BSA-stimulated signaling pathways to activate the AP-1 transcription with a peak at 1 h. AGE-BSA also induced VEGF mediated by AP-1, however, there was a difference of effect between AGE-BSA and CML-BSA in the activation of AP-1. AGE-BSA-stimulated AP-1 activity showed a peak at 5 h, which paralleled the formation of ROS. Reduction of AGE-BSA with NaBH(4) or addition of vitamin E attenuated the AGE-BSA-stimulated signaling pathways leading to the same pattern as for CML-BSA-stimulated signals. These results suggest an important role for AGEs in stimulation of the development of angiogenesis observed in diabetic complications, and that ROS accelerates the AGE-stimulated VEGF expression.

Vascular endothelial growth factors C and D and their VEGFR-2 and 3 receptors in blood and lymphatic vessels in healthy and arthritic synovium.

OBJECTIVE: To localize vascular endothelial growth factor C (VEGF-C) and VEGF-D in synovial specimens in relation to their VEGFR-2 and VEGFR-3 receptors in blood and lymphatic vessels. METHODS: Immunohistochemical staining and messenger RNA analysis from control and arthritic synovial membrane specimens. RESULTS: Quantitative RT-PCR disclosed that VEGF-C mRNA copy numbers were higher than VEGF-D mRNA copy numbers in the rheumatoid arthritis (RA), osteoarthritis, and control patient groups studied (p < 0.01). Immunohistochemical staining localized VEGF-C to synovial lining cell layer, pericytes, and smooth muscle cells of blood vessels. The number of VEGF-C positive cells was increased in the synovial lining of ankylosing spondylitis (AS) and RA compared to control synovium. However, in contrast to control synovial lining, little if any VEGF-D was detected in AS or RA synovial lining. VEGFR-2 expressing stromal blood vessels, also positive for the vascular endothelial marker PAL-E and the basement membrane marker laminin, were more abundant in RA and AS than in controls. Interestingly, the lymphatic endothelial receptor VEGFR-3 was also expressed in most synovial vessels, especially in the sublining capillaries and venules. CONCLUSION: VEGF-C is strongly expressed in the hypertrophic synovial lining of arthritic joints, whereas VEGF-D expression is very low in AS and RA. The expression of VEGF-C and VEGF-D in pericytes and smooth muscle cells suggests that these factors may have a role in maintaining vascular homeostasis. The VEGF receptors VEGFR-2 and VEGFR-3 are present in most of the sublining blood vessels. The expression of the lymphatic marker VEGFR-3 in the sublining blood vessels may relate to fluid filtration and/or fenestrations. The relatively few lymphatic vessels along with increased vascular permeability in RA may contribute to the development of tissue edema and joint stiffness.

Increased expression of Vascular Endothelial Growth Factor-A in seasonal allergic rhinitis.

Increased vascular dilatation and permeability characterize allergic rhinitis. In this study oligonucleotide microarrays (Affymetrix HuGe95A) were used to identify differentially expressed vasoactive genes in nasal biopsies from 23 patients with symptomatic seasonal allergic rhinitis (SAR) and 12 healthy controls. RNA was extracted from the biopsies and pooled in three patient and three control pools. Out of 12,626 analysed transcripts, 39 were higher and 81 lower in the patients. Of these transcripts two have vasoactive effects: Vascular Endothelial Growth Factor-A (VEGF-A) and the Beta-1-Adrenergic Receptor. Both were higher in patients than in controls. The mean +/- SEM expression levels in arbitrary units of VEGF-A were 130 +/- 123 in the patients and 59 +/- 53 in the controls. The fold ratio in expression levels between patients/controls was 2.2. The corresponding values for the beta-1-adrenergic receptor were 129 +/- 123 in the patients and 40 +/- 31 in the controls. The fold ratio between patient/controls was 3.2. The role of VEGF-A was assessed by determining VEGF-A concentrations in nasal fluids from another 30 patients with SAR before and after allergen provocation. VEGF-A increased from 124.3 +/- 30.2 to 163.2 +/- 37.8 pg/ml after challenge, P < 0.05. In summary, oligonucleotide microarray analysis of nasal biopsies and protein analyses of nasal fluids indicate that VEGF-A may be an important mediator in SAR.

Insights into the molecular pathogenesis and targeted treatment of lymphedema.

Abnormal function of the lymphatic vessels is associated with a variety of diseases, such as tumor metastasis and lymphedema. The development of strategies for local and controlled induction or inhibition of lymphangiogenesis would thus be of major importance for the treatment of such diseases. Two growth factors, vascular endothelial growth factor C (VEGF-C) and D (VEGF-D), have been found to be important in the proper formation and maintenance of the lymphatic network, through their receptor VEGFR-3. In patients with lymphedema, heterozygous inactivation of VEGFR-3 leads to primary lymphedema due to defective lymphatic drainage in the limbs. We have shown that VEGF-C gene transfer to the skin of mice with lymphedema induces regeneration of the cutaneous lymphatic vessel network. However, as is the case with VEGF, high levels of VEGF-C cause blood vessel growth and leakiness, resulting in tissue edema. Strategies to avoid these side-effects have also been developed. This new field of reseach has important implications for the development of new therapies for human lymphedema.