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

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. Immunohistochemical staining and messenger RNA analysis from control and arthritic synovial membrane specimens. 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. 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.

Paavonen K ，Mandelin J ，Partanen T ，Jussila L ，Li TF ，Ristimaki A ，Alitalo K ，Konttinen YT ... -  《JOURNAL OF RHEUMATOLOGY》

Expression and localization of vascular endothelial growth factor-C in rheumatoid arthritis synovial tissue.

Wauke K ，Nagashima M ，Ishiwata T ，Asano G ，Yoshino S ... -  《JOURNAL OF RHEUMATOLOGY》

Analysis of vascular gene expression in arthritic synovium by laser-mediated microdissection.

Hashimoto A ，Tarner IH ，Bohle RM ，Gaumann A ，Manetti M ，Distler O ，Steinmeyer J ，Ulfgren AK ，Schulz A ，Gay S ，Müller-Ladner U ，Neumann E ... -  《ARTHRITIS AND RHEUMATISM》

Expression of vascular endothelial growth factor receptor 3 in blood and lymphatic vessels of lung adenocarcinoma.

Vascular endothelial growth factor receptor 3 (VEGFR-3) has been proposed as a marker for lymphatic endothelial cells. This study investigated the expression of VEGFR-3 in the tumour vessels of lung adenocarcinoma and evaluated whether VEGFR-3 staining was useful for identifying lymphatic vessels within the tumour stroma. It also explored whether active growth of lymphatic vessels occurred in lung adenocarcinoma. Formalin-fixed, paraffin-embedded specimens obtained from 60 cases of lung adenocarcinoma, including five cases of pure bronchiolo-alveolar carcinoma (BAC) without stromal, vascular, and pleural invasion, were examined. No VEGFR-3-positive vessels were observed in pure BAC, but varying numbers of VEGFR-3-positive vessels were found in 39 of 55 (70.9%) invasive adenocarcinomas. A comparison of serial sections stained for VEGFR-3, CD31, and laminin-1 showed that most of the VEGFR-3-positive vessels appeared to be blood vessels (CD31-positive, laminin-1-positive), but some had the characteristics of lymphatic vessels (variable staining for CD31, little or no staining for laminin-1). VEGFR-3 staining highlighted lymphatic invasion by cancer cells; this invasion could not be detected by CD31 or haematoxylin and eosin (H&E) staining. Active growth of lymphatic vessels (as indicated by nuclear Ki-67 labelling of the endothelium) was observed in five tumours, four of which showed a high level of lymphatic invasion by cancer cells. It was concluded that VEGFR-3 immunostaining did not discriminate clearly between vascular and lymphatic endothelial cells, since expression of VEGFR-3 can be up-regulated in tumour blood vessels. However, VEGFR-3 staining combined with laminin-1 and CD31 staining would be useful for identifying lymphatic vessels and their invasion by tumour cells in a more objective way. Finally, proliferation of lymphatic endothelial cells may occur in association with lymphatic invasion by cancer cells.

Niki T ，Iba S ，Yamada T ，Matsuno Y ，Enholm B ，Hirohashi S ... -  《JOURNAL OF PATHOLOGY》

The angiogenic pathway "vascular endothelial growth factor/flk-1(KDR)-receptor" in rheumatoid arthritis and osteoarthritis.

Active angiogenesis, together with an up-regulation of angiogenic factors, is evident in the synovium of both rheumatoid arthritis (RA) and osteoarthritis (OA). The present study assessed, by immunohistochemistry, the microvessel density in the synovium of these arthritides and in normal controls, in relation to the expression of the angiogenic factors vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) and the apoptosis-related proteins bcl-2 and p53. More importantly, using the novel 11B5 MAb, the activated "VEGF/flk-1(KDR)-receptor" microvessel density was assessed. VEGF expression in fibroblasts was diffuse in both RA and OA. Diffuse PD-ECGF expression of fibroblasts was noted in all cases of RA, while fibroblast reactivity was focal in the OA material. The standard microvessel density (sMVD), as assessed with the anti-CD31 monoclonal antibody (MAb), was higher in RA (64+/-12) and in OA (65+/-16) than in normal tissues (52+/-8; p=0.008 and 0.0004, respectively). The activated microvessel density (aMVD), assessed with the 11B5 MAb, was significantly higher in RA (29+/-10) than in OA (17+/-4; p<0.0001) and than in normal tissues (14+/-2; p<0.0001). The "activation ratio" (aMVD/sMVD) was statistically higher in RA (0.46+/-0.17) than in OA and normal synovial tissues, the latter two having a similar ratio (0.28+/-0.08 and 0.26+/-0.03, respectively). Cytoplasmic bcl-2 expression was frequent in the synovial cells of OA, but rare in RA. Nuclear p53 protein accumulation was never observed. It is suggested that the angiogenic pathway VEGF/flk-1(KDR) may play an important role in the pathogenesis of RA and OA. Thus, failure of VEGF/flk-1(KDR) activation, in the presence of increased VEGF expression, may indicate a synovium with an impaired capacity to establish a viable vasculature, consistent with the degenerative nature of OA. On the other hand, the activated angiogenesis in RA shows a functional, still pathologically up-regulated VEGF/flk-1(KDR) pathway. Whether restoration of an impaired VEGF/flk-1(KDR) pathway in OA, or inhibition of this in RA, would prove of therapeutic importance requires further investigation.

Giatromanolaki A ，Sivridis E ，Athanassou N ，Zois E ，Thorpe PE ，Brekken RA ，Gatter KC ，Harris AL ，Koukourakis IM ，Koukourakis MI ... -  《JOURNAL OF PATHOLOGY》