Enhancing Renal Lymphatic Expansion Prevents Hypertension in Mice.

RATIONALE: Hypertension is associated with renal infiltration of activated immune cells; however, the role of renal lymphatics and immune cell exfiltration is unknown. OBJECTIVE: We tested the hypotheses that increased renal lymphatic density is associated with 2 different forms of hypertension in mice and that further augmenting renal lymphatic vessel expansion prevents hypertension by reducing renal immune cell accumulation. METHODS AND RESULTS: Mice with salt-sensitive hypertension or nitric oxide synthase inhibition-induced hypertension exhibited significant increases in renal lymphatic vessel density and immune cell infiltration associated with inflammation. Genetic induction of enhanced lymphangiogenesis only in the kidney, however, reduced renal immune cell accumulation and prevented hypertension. CONCLUSIONS: These data demonstrate that renal lymphatics play a key role in immune cell trafficking in the kidney and blood pressure regulation in hypertension.

Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture.

Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines.

TNF-alpha promotes lymphangiogenesis and lymphatic metastasis of gallbladder cancer through the ERK1/2/AP-1/VEGF-D pathway.

BACKGROUND: Tumor necrosis factor-alpha (TNF-α), a key player in cancer-related inflammation, was recently demonstrated to be involved in the lymphatic metastasis of gallbladder cancer (GBC). Vascular endothelial growth factor D (VEGF-D) is a key lymphangiogenic factor that is associated with lymphangiogenesis and lymph node metastasis in GBC. However, whether VEGF-D is involved in TNF-α-induced lymphatic metastasis of GBC remains undetermined. METHODS: The expression of VEGF-D in patient specimens was detected by immunohistochemistry and the relationship between VEGF-D in the tissue and TNF-α in the bile of the matching patients was analyzed. The VEGF-D mRNA and protein levels after treatment with exogenous TNF-α in NOZ, GBC-SD and SGC-996 cell lines were measured by real-time PCR and ELISA. The promoter activity and transcriptional regulation of VEGF-D were analyzed with the relative luciferase reporter assay, mutant constructs, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP) assay, RNA interference and Western blotting. Inhibitors of JNK, p38 MAPK and ERK1/2 were used to explore the upstream signaling effector of AP-1. We used lentiviral vector expressing a VEGF-D shRNA construct to knockdown VEGF-D gene in NOZ and GBC-SD cells. The role of the TNF-α-VEGF-D axis in the tube formation of human dermal lymphatic endothelial cells (HDLECs) was determined using a three-dimensional coculture system. The role of the TNF-α - VEGF-D axis in lymphangiogenesis and lymph node metastasis was studied via animal experiment. RESULTS: TNF-α levels in the bile of GBC patients were positively correlated with VEGF-D expression in the clinical specimens. TNF-α can upregulate the protein expression and promoter activity of VEGF-D through the ERK1/2 - AP-1 pathway. Moreover, TNF-α can promote tube formation of HDLECs, lymphangiogenesis and lymph node metastasis of GBC by upregulation of VEGF-D in vitro and in vivo. CONCLUSION: Taken together, our data suggest that TNF-α can promote lymphangiogenesis and lymphatic metastasis of GBC through the ERK1/2/AP-1/VEGF-D pathway.

VEGF-D-induced draining lymphatic enlargement and tumor lymphangiogenesis promote lymph node metastasis in a xenograft model of ovarian carcinoma.

BACKGROUND: Vascular endothelial growth factor (VEGF)-D has been shown to promote lymph node metastasis in several cancers. Although generally overexpressed in ovarian carcinoma, its role in nodal dissemination of this cancer is unclear. To clarify the role of VEGF-D and the underlying molecular mechanisms, we investigated the function of VEGF-D using a mouse xenograft model of ovarian cancer. METHODS: Human ovarian serous adenocarcinoma SKOV3 cells were transfected with VEGF-D recombinant plasmid DNA, or with control vectors. The cells were injected subcutaneously into the footpads of nude mice. Tumor growth was evaluated weekly. Draining lymphatics were observed grossly with Evan's blue lymphangiography. Tumoral lymphatics were delineated with both Evan's blue and LYVE-1 immunostaining. Tumor metastases to lymph nodes were evaluated by H&E and CA125/CD40 staining. Expression of VEGF-D in primary tumors and levels of CA125 in involved lymph nodes were examined by immunohistochemistry. Tumor cell apoptosis was analyzed by Hoechst dyeing. RESULTS: Mice bearing VEGF-D overexpressing xenografts showed a significantly higher rate of lymph node metastasis and markedly greater tumor volume compared with the controls. The functional lymphatic vessels were denser and enlarged in marginal and central tumor portions. Additionally, higher CA125 expression was observed in the involved lymph nodes. Mice bearing VEGF-D overexpressing xenografts also exhibited a markedly lower apoptotic index compared with the controls. CONCLUSIONS: Our data demonstrate the important role of VEGF-D in promoting lymph node metastasis by increasing tumor lymphangiogenesis, stimulating draining lymphatic vessel formation, and enhancing tumor invasiveness. Our findings show that VEGF-D can be a promising therapeutic target for ovarian cancer.

Protumoral roles of melanoma inhibitory activity 2 in oral squamous cell carcinoma.

BACKGROUND: The role of melanoma inhibitory activity 2 (MIA2) was examined in human oral squamous cell carcinoma (OSCC). METHODS: MIA2 role was examined by immunohistochemistry of human OSCCs and knockdown studies using human 3 OSCC cell lines with MIA2 expression. RESULTS: MIA2 expression was observed in 62 (66.7%) of 93 OSCCs and was associated with tumour expansion and nodal metastasis. Melanoma inhibitory activity 2 expression was inversely correlated with intratumoral infiltration of lymphocytes. Invasion and anti-apoptotic survival were reduced by MIA2 knockdown in HSC3 cells. MOLT-3 lymphocytes infiltrating the HSC3 cell layer was enhanced by MIA2 knockdown or MIA2 depletion with the antibody. In HSC3 cells, MIA2 knockdown decreased the expressions of vascular endothelial growth factor (VEGF), VEGF-C, and VEGF-D. The downregulation of VEGF-C and -D was caused by inhibition of p38 and extracellular signal-regulated kinase (ERK)1/2, respectively. Melanoma inhibitory activity 2 was co-precipitated with integrin α4 andα5 in HSC3 cells. Integrin α4 knockdown decreased p38 phosphorylation and increased apoptosis, whereas integrin α5 knockdown decreased c-Jun N-terminal kinase (JNK) phosphorylation and apoptosis. Inhibition of JNK decreased apoptosis in the HSC3 cells. CONCLUSION: These findings suggest that the roles of MIA2 might be based on the variety of the integrins and the subtypes of mitogen-activated protein kinase.

Vascular endothelial growth factor-D is a key molecule that enhances lymphatic metastasis of soft tissue sarcomas.

Studies on lymph node metastasis of soft tissue sarcomas are insufficient because of its rarity. In this study, we examined the expressions of vascular endothelial growth factor (VEGF)-C and VEGF-D in soft tissue sarcomas metastasized to lymph nodes. In addition, the effects of the two molecules on the barrier function of a lymphatic endothelial cell monolayer against sarcoma cells were analyzed. We examined 7 patients who had soft tissue sarcomas with lymph node metastases and who had undergone neither chemotherapy nor radiotherapy before lymphadenectomy. Immunohistochemistry revealed that 2 of 7 sarcomas that metastasized to lymph nodes expressed VEGF-C both in primary and metastatic lesions. On the other hand, VEGF-D expression was detected in 4 of 7 primary and 7 of 7 metastatic lesions, respectively. Interestingly, 3 cases that showed no VEGF-D expression at primary sites expressed VEGF-D in metastatic lesions. Recombinant VEGF-C at 10(-8) and VEGF-D at 10(-7)and 10(-8)g/ml significantly increased the random motility of lymphatic endothelial cells compared with controls. VEGF-D significantly increased the migration of sarcoma cells through lymphatic endothelial monolayers. The fact that VEGF-D induced the migration of fibrosarcomas through the lymphatic endothelial monolayer is the probable reason for the strong relationship between VEGF-D expression and lymph node metastasis in soft tissue sarcomas. The important propensities of this molecule for the increase of lymph node metastases are not only lymphangiogenesis but also down-regulation of the barrier function of lymphatic endothelial monolayers, which facilitates sarcoma cells entering the lymphatic circulation.

Stromal factors SDF1α, sFRP1, and VEGFD induce dopaminergic neuron differentiation of human pluripotent stem cells.

Human embryonic stem cell (hESC)-derived dopaminergic (DA) neurons hold potential for treating Parkinson's disease (PD) through cell replacement therapy. Generation of DA neurons from hESCs has been achieved by coculture with the stromal cell line PA6, a source of stromal cell-derived inducing activity (SDIA). However, the factors produced by stromal cells that result in SDIA are largely undefined. We previously reported that medium conditioned by PA6 cells can generate functional DA neurons from NTera2 human embryonal carcinoma stem cells. Here we show that PA6-conditioned medium can induce DA neuronal differentiation in both NTera2 cells and the hESC I6 cell line. To identify the factor(s) responsible for SDIA, we used large-scale microarray analysis of gene expression combined with mass spectrometric analysis of PA6-conditioned medium (CM). The candidate factors, hepatocyte growth factor (HGF), stromal cell-derived factor-1 α (SDF1α), secreted frizzled-related protein 1 (sFRP1), and vascular endothelial growth factor D (VEGFD) were identified, and their concentrations in PA6 CM were established by immunoaffinity capillary electrophoresis. Upon addition of SDF1α, sFRP1, and VEGFD to the culture medium, we observed an increase in the number of cells expressing tyrosine hydroxylase (a marker for DA neurons) and ßIII-tubulin (a marker for immature neurons) in both the NTera2 and I6 cell lines. These results indicate that SDF1α, sFRP1, and VEGFD are major components of SDIA and suggest the potential use of these defined factors to elicit DA differentiation of pluripotent human stem cells for therapeutic intervention in PD.

Lymphatic vessels and related factors in adenoid cystic carcinoma of the salivary gland.

Adenoid cystic carcinoma of the salivary gland preferentially metastasizes to distant organs. It rarely metastasizes to lymph nodes. Recently, lymphangiogenesis has been associated with lymph node metastasis. Therefore, lymphangiogenesis in adenoid cystic carcinoma was evaluated from the number of lymphatic vessels and the expression of lymphangiogenic factors. Immunohistochemistry and molecular analysis were performed on clinical materials (29 cases for immunohistochemistry and 9 cases for molecular analysis). Normal submandibular gland was used as a negative control of lymphangiogenesis (10 cases for immunohistochemistry and 5 cases for molecular analysis). In adenoid cystic carcinoma, podoplanin-positive lymphatic vessels were small and often constricted, and localized to the tumor periphery. They did not have Ki67-positive endothelial cells. The lymphatic vessel density of the tumor did not exceed that of the salivary gland. By reverse transcriptase-polymerase chain reaction, adenoid cystic carcinoma and the salivary gland expressed vascular endothelial growth factor receptor-3 (VEGFR-3) similarly but VEGF-C and VEGF-D differently. Adenoid cystic carcinoma expressed VEGF-C, whereas the salivary gland expressed both VEGF-C and VEGF-D. VEGF-C was weak in adenoid cystic carcinoma and strong in the salivary gland. Real-time reverse transcriptase-polymerase chain reaction of VEGF-C showed that the ratio of the tumor to the salivary gland was 1 to 30 (P<0.01). Immunohistochemistry barely detected VEGF-C in adenoid cystic carcinoma. VEGF-C was expressed faintly by the tumor cells. VEGF-C and VEGF-D were detected in the serous acinar and duct cells and in the duct contents in the salivary gland. VEGFR-3 appeared to be expressed by lymphatic vessels in both adenoid cystic carcinoma and the salivary gland. These results indicate that lymphangiogenesis does not occur in adenoid cystic carcinoma. This condition would lead to the uncommon lymphatic metastasis.

Lymphangiogenesis in deep infiltrating endometriosis.

BACKGROUND: In patients diagnosed with deep infiltrating endometriosis (DIE), foci of endometriosis are detected in mesorectal lymph nodes (LNs) after segmental bowel resection and in pelvic sentinel LNs. Lymph vessels (LVs) seem to be the possible routes for the dissemination of endometriotic cells from DIE-lesions to LN. Therefore, we conducted a study to investigate the occurrence and density of LV and lymphangiogenic growth factors in DIE. METHODS: Included in this study were 38 premenopausal women who underwent surgery due to symptomatic rectovaginal DIE. In order to identify LV, immunohistochemical analysis with anti-Podoplanin (D2-40), LYVE-1 and Prox-1 was performed. Furthermore, the expression of VEGF-C and VEGF-D in endometriotic tissue was investigated. RESULTS: LV density (LVD) of DIE lesions was significantly higher compared with healthy corresponding tissue. All LV makers could be detected, and the density of LYVE-1- or Prox-1-positive LV was significantly higher than that of D2-40-positive LV. Endometriotic epithelial cells and stromal cells showed a moderate to strong VEGF-C and VEDF-D expression. CONCLUSIONS: DIE lesions have lymphangiogenic properties, probably leading to endometriosis-like cells in lymphatic vessels and LNs featuring a loco-regional disease.

Vascular endothelial growth factor C and D expression correlates with lymph node metastasis and poor prognosis in patients with resected esophageal cancer.

Vascular endothelial growth factors C (VEGF-C) and D (VEGF-D) are important lymphangiogenic factors in human cancers. We studied the expression of VEGF-C and VEGF-D using immunohistochemistry in 73 resected esophageal cancer specimens, and correlated the results with patient clinicopathologic features and survival. High expression of VEGF-C was identified in 40 (54.7%) patients, and it correlated positively with histological grade (p=0.038), tumor stage (p=0.01), depth of tumor invasion (p=0.036) and lymph node metastasis (p=0.001). In 48 of 73 (65.7%) tumors, the VEGF-D protein was also expressed at high levels. VEGF-D immunoreactivity significantly correlated with tumor location (p=0.027), size of tumor (p=0.015), histological grade (p=0.02), depth of invasion (p=0.001) and lymph node metastasis (p=0.018). In logistic multivariate analysis, high expression of VEGF-C (OR 1.941, 95% CI 1.263-7.289, p=0.024) was associated with lymph node metastasis. Calculating the prognostic relevance revealed that both VEGF-C and VEGF-D correlated with decreased overall survival (p=0.01, p=0.003), disease free survival (p=0.02, p=0.006), and cancer-specific survival (p=0.03, p=0.005). In conclusion, our results suggest that high levels of both VEGF-C and VEGF-D proteins are associated with lymph node involvement, and that VEGF-C expression is an independent predictor of risk for lymph node metastasis in esophageal cancer. In locally advanced disease, overexpression of VEGF-C and VEGF-D may be useful in identifying patients who are more likely to have a poor prognosis even after curative resection.

Deguelin--an inhibitor to tumor lymphangiogenesis and lymphatic metastasis by downregulation of vascular endothelial cell growth factor-D in lung tumor model.

Deguelin, a rotenoid of the flavonoid family, has been reported to possess antiproliferative and anticarcinogenic activities in several cell lines and tumor models. However, it is still unclear whether deguelin effectively inhibits tumor-associated lymphangiogenesis and lymphatic metastasis. Since tumor production of vascular endothelial cell growth factor (VEGF)-D was associated with tumor lymphangiogenesis and lymphatic metastasis, we established the mouse lymphatic metastasis model by transfecting high expression VEGF-D into LL/2 Lewis lung cells (VEGF-D-LL/2) and explored the effects of deguelin on lymphatic metastasis in the immunocompetent C57BL/6 mice. Our results indicated that deguelin inhibited proliferation, migration of VEGF-D-LL/2 cells via downregulating AKT and mitogen-activated protein kinase pathway and interfered tube formation of lymphatic vascular endothelial cells on matrigel at nanomolar concentrations. Deguelin significantly downregulated the expression of VEGF-D both at mRNA and protein levels in VEGF-D-LL/2 cells in a dose-dependent manner. In the in vivo study, intraperitoneal administration of deguelin (4 mg/kg) remarkably inhibited the tumor-associated lymphangiogenesis and lymphatic metastasis. The rates of lymph node and lung metastasis in deguelin-treated mice were 0 and 16.7% compared with 58.3 and 83.3% in control group mice, respectively. Deguelin also resulted in a remarkable delay of tumor growth and prolongation of life span. Immunohistochemical staining with antibodies against VEGF-D, LYVE-1 and VEGFR-3 revealed fewer positive vessel-like structures in deguelin-treated mice compared with control group mice. Taken together, we demonstrate for the first time that deguelin suppresses tumor-associated lymphangiogenesis and lymphatic metastasis by downregulation of VEGF-D both in vitro and in vivo.

Impaired lymphangiogenesis due to excess vascular endothelial growth factor-D/Flt-4 signalling in the skin of patients with systemic sclerosis.

BACKGROUND: Vascular abnormalities are one of the primary pathological components of systemic sclerosis (SSc). However, it has not been determined if there are also abnormalities in the formation of lymphatic vessels in SSc. OBJECTIVE: To evaluate lymphangiogenic activity in SSc skin. METHODS: The numbers of D2-40-positive lymphatic vessels in skin specimens from healthy control subjects and patients with SSc were counted and compared. Quantitative real-time polymerase chain reaction (PCR) was performed to determine mRNA levels of vascular endothelial growth factor (VEGF)-D and Flt-4 (fms-related tyrosine kinase 4, VEGFR-3, one of the receptors for VEGF-D) in the skin. Serum VEGF-D levels were measured with specific enzyme-linked immunosorbent assays. RESULTSZ: The number of lymphatic vessels in patients with SSc was significantly decreased compared with healthy control subjects. Mean relative transcript levels of FIGF (VEGF-D) and FLT4 (Flt-4) in skin tissue from patients with SSc were significantly increased compared with healthy control subjects. By the analysis of the association between serum VEGF-D levels and the clinical or laboratory features, we found that patients with SSc with higher serum VEGF-D levels more frequently have skin ulcers than those with normal VEGF-D levels. CONCLUSIONS: A systemic increase of VEGF-D, as well as local overexpression of FIGF and FLT4, may be the cause of disturbed lymphangiogenesis in SSc skin and play a role in the pathogenesis of SSc. We showed the possibility that regulation of VEGF-D/Flt-4 signalling could lead to new treatment of skin ulcers in SSc by controlling the formation of lymphatic vessels.

Up-regulation of vascular endothelial growth factor-D expression in clear cell renal cell carcinoma by CD74: a critical role in cancer cell tumorigenesis.

Elevation of CD74 is associated with a number of human cancers, including clear cell renal cell carcinoma (ccRCC). To understand the role of CD74 in the oncogenic process of ccRCC, we ectopically expressed CD74 in human embryonic kidney 293 cells (HEK/CD74) and evaluated its oncogenic potential. Through overexpression of CD74 in HEK293 and Caki-2 cells and down-regulation of CD74 in Caki-1 cells, we show that vascular endothelial growth factor-D (VEGF-D) expression is modified accordingly. A significant, positive correlation between CD74 and VEGF-D is found in human ccRCC tissues (Pearson's correlation, r = 0.65, p < 0.001). In HEK/CD74 xenograft mice, CD74 significantly induced the formation of tumor masses, increased tumor-induced angiogenesis, and promoted cancer cell metastasis. Blockage of VEGF-D expression by small interference RNA resulted in a decrease in cell proliferation, invasion, and cancer cell-induced HUVEC migration enhanced by CD74. Furthermore, we provide evidence that the intracellular signaling cascade responsible for VEGF-D up-regulation by CD74 is both PI3K/AKT- and MEK/ERK-dependent, both of which are associated with NF-kappaB nuclear translocation and DNA-binding activity. These results suggest that VEGF-D is crucial for CD74-induced human renal carcinoma cancer cell tumorigenesis.

VEGF-C and VEGF-D expression is correlated with lymphatic vessel density and lymph node metastasis in oral squamous cell carcinoma: Implications for use as a prognostic marker.

The prognosis of patients with oral squamous cell carcinoma (SCC) is influenced by the presence of lymph node metastasis. In this study, we analyzed the relationship between lymphangiogenesis and the expression of VEGF-C and VEGF-D in association with lymph node metastasis in oral SCC. Oral SCC biopsy specimens (160 cases) were examined for lymphatic vessel density (LVD) and the expression of VEGF-C and VEGF-D immunohistochemically. The levels of VEGF-C and VEGF-D expression and LVD were significantly associated with lymph node metastasis (p<0.001). The expression of VEGF-C and VEGF-D increased the LVD significantly (p<0.001). Multivariate analysis showed that VEGF-C expression and LVD were significantly associated with lymph node metastasis (p<0.001). This study presents clinical evidence for the important roles of VEGF-C and VEGF-D in lymphangiogenesis and lymphatic metastasis of oral SCC, and suggests that VEGF-C or LVD can effectively predict lymphatic metastasis of oral SCC.

Dietary hemin promotes colonic preneoplastic lesions and DNA damage but not tumor development in a medium-term model of colon carcinogenesis in rats.

Red and processed meat consumption has been strongly related to increase the risk of colorectal cancer (CRC), although its impact is largely unknown. Hemin, an iron-containing porphyrin, is acknowledged as a putative factor of red and processed meat pro-carcinogenic effects. The aim of this study was to investigate the effects of high dietary hemin on the promotion/progression stages of 1,2-dimethylhydrazine (1,2-DMH)-induced colon carcinogenesis. Twenty-four Wistar male rats were given four subcutaneous 1,2-DMH injections and received either balanced diet or balanced diet supplemented with hemin 0.5 mmol/kg for 23 weeks. Colon specimens were analyzed for aberrant crypt foci (ACF) and tumor development. Dietary hemin significantly increased ACF number and fecal water cytotoxicity/genotoxicity in Caco-2 cells when compared to 1,2-DMH control group. However, tumor incidence, multiplicity and cell proliferation did not differ between 1,2-DMH + hemin and 1,2-DMH control group. Gene expression analysis of 91 target-genes revealed that only three genes (Figf, Pik3r5 and Tgfbr2) were down-regulated in the tumors from hemin-fed rats compared to those from 1,2-DMH control group. Therefore, the findings of this study show that high hemin intake promotes mainly DNA damage and ACF development and but does not change the number nor incidence of colon tumors induced by 1,2-DMH in male rats.

Molecular and Cellular Effect of Angiotensin 1-7 on Hypertensive Kidney Disease.

BACKGROUND: Studies implicate that angiotensin 1-7 (Ang1-7) imparts protective effects in the kidney. However, its relevance in hypertensive kidney disease is not fully understood. The purpose of this study was to explore the role of Ang1-7 on renal damage/remodeling during hypertension and its potential underlying molecular-cellular mechanisms. METHODS: Hypertension was induced in adult Sprague-Dawley rats by infusion of aldosterone (ALDO; 0.75 µg/hour) for 4 weeks with or without co-treatment of Ang1-7 (1 mg/kg/day). Untreated rats served as controls. Systolic blood pressure was monitored by tail-cuff technique. Renal fibrosis was evaluated by picrosirius red staining and renal collagen volume fraction was quantitated using imaging analyzing system. The expression of profibrotic factors [transforming growth factor-ß1 (TGF-ß1), platelet-derived growth factor-D (PDGF-D), fibroblast growth factor-1 (FGF-1), vascular endothelial growth factor-D (VEGF-D), and tissue inhibitors of metalloproteinases (TIMPs)] and free radical producing enzymes (inducible nitric oxide synthase and nicotinamide adenine dinucleotide phosphate [NADPH] oxidase) in the kidney were examined by reverse transcription-polymerase chain reaction and western blot. Renal oxidative stress was assessed by malondialdehyde (MDA) measurement. RESULTS: Chronic ALDO infusion caused hypertension and hypertensive renal disease represented as glomerular damage/sclerosis. Ang1-7 co-treatment did not affect blood pressure in ALDO-treated rats, but significantly attenuated the glomerular damage/fibrosis. ALDO treatment significantly elevated renal expression of profibrogenic factors, including TGF-ß1, TIMP-1/TIMP-2, FGF-1, PDGF-D, and VEGF-D, whereas Ang1-7 co-treatment significantly reduced renal TGF-ß1, TIMP-1/TIMP-2, and FGF-1, but not PDGF-D and VEGF-D. Furthermore, ALDO infusion elevated NADPH oxidase (gp91phox) and MDA in the kidney, which was attenuated by Ang1-7 co-treatment. CONCLUSIONS: Ang1-7 plays a protective role in the hypertensive kidney disease independent of blood pressure. The beneficial effects of Ang1-7 are likely mediated via suppressing TGF-ß/FGF-1 pathways and oxidative stress.

Role of macrophages in inflammatory lymphangiogenesis: Enhanced production of vascular endothelial growth factor C and D through NF-kappaB activation.

The close association of inflammation, angiogenesis and cancer progression is now highlighted, and in this study we especially focused on a close association of inflammation and lymphangiogenesis. We found that proinflammatory cytokine, interleukin-1beta (IL-1beta), could induce lymphangiogenesis in mouse cornea through enhanced production of potent lymphangiogenic factors, VEGF-A, VEGF-C and VEGF-D. IL-1beta-induced lymphangiogenesis, but not angiogenesis, was inhibited by administration of a selective anti-VEGF receptor-3 (VEGFR-3) neutralizing antibody. And in mouse cornea we observed recruitment of monocyte/macrophages and neutrophils by IL-1beta implanted cornea. Depletion of macrophages by a bisphosphonate encapsulated in liposomes inhibited this IL-1beta-induced lymphangiogenesis and also up-regulation of VEGF-A, VEGF-C, and VEGF-D. Furthermore, IL-1beta-induced lymphangiogenesis and angiogenesis were suppressed by NF-kappaB inhibition with marked suppression of VEGF-A, VEGF-C, and VEGF-D expression.

Role of vascular endothelial growth factor-C and -D mRNA in breast cancer.

Vascular endothelial growth factor (VEGF)-C and VEGF-D belong to the VEGF family, and are thought to be involved in lymphangiogenesis and angiogenesis. At present, this is the only known system that can induce lymphatic vessel growth in the body. However, the roles of VEGF-C and VEGF-D in breast cancer tissue have not been clarified. In the present study, we measured the mRNA expression of VEGF-C and VEGF-D in the breast cancer tissue of 109 patients by real-time polymerase chain reaction (RT-PCR). Between non-infiltrating breast cancer (n=6) and infiltrating breast cancer (n=103), there were no significant differences in the mRNA expression of VEGF-C and VEGF-D. In infiltrating cancer, the expression of HER2 exhibited a positive correlation to VEGF-C and VEGF-D mRNA expression (p=0.027, p=0.048). However, mRNA expression ofVEGF-C and VEGF-D did not exhibit any significant correlation to lymphatic vessel invasion or lymph node metastasis. Among patients without lymph node metastasis, the mRNA expression of VEGF-C and VEGF-D for patients with lymphatic vessel invasion was significantly higher than that for patients without lymphatic vessel invasion (p=0.001, p=0.050). The results suggest that, in breast cancer, VEGF-C and VEGF-D are involved in lymphatic vessel invasion prior to lymph node metastasis, and their expression decreases after lymph node metastasis occurs.

[Relation of vascular endothelial growth factor-D expression to microvessel density, microlymphatic vessel density, and lymph-node metastasis of lung adenocarcinoma].

OBJECTIVE: To investigate the relationship of expression of vascular endothelial growth factor (VEGF)-D to microvessel density (MVD), microlymphatic vessel density (MLVD), and lymph node metastasis in lung adenocarcinoma. METHODS: Fresh specimens of lung adenocarcinoma were collected form 48 patients with lung adenocarcinoma, 28 males and 20 females, aged 35 - 78, during operation. Semi-quantitative RT-PCR was used to detect the mRNA expression of VEGF-D, and immunohistochemistry was used to detect the protein expression of VEGF-D, CD34 (marker of MVD), and VEGF receptor (VEGFR)-3 (marker of MLV). RESULTS: The expression of VEGF-D mRNA in the lung cancer was significantly higher than that in the normal lung tissue, and the expression of VEGF-D protein in the cancerous invasive edge was significantly higher than that in the center of cancerous tissues. Twenty-one of the 29 lung adenocarcinoma patients at stages III - IV were VEGF-D positive, a proportion significantly higher than that of the patients at stages I - II (7/19, P = 0.015). The MLVD of the VEGF-D positive group was 10.25 +/- 2.50, significantly higher than that of the VEGF-D negative group (6.8 +/- 2.2, P < 0.01). Twenty-three of the 28 VEGF-D positive patients showed lymph node metastasis, a proportion significantly higher than that of the VEGF-D negative group (9/20, P = 0.012). CONCLUSION: VEGF-D is related with the lymphangiogenesis and lymph node metastasis in lung adenocarcinoma, but not with angiogenesis.

VEGF-D is expressed in activated lymphoid cells and in tumors of hematopoietic and lymphoid tissues.

Vascular Endothelial Growth Factor (VEGF)-D is a member of the VEGF family of angiogenic growth factors that activate the Vascular Endothelial Growth Factor Receptor (VEGFR)-2 and VEGFR-3, which are mainly expressed in blood and lymphatic vessels. Here we have analyzed by using monoclonal antibodies, the expression of VEGF-D and its cognate receptor VEGFR-3 in normal and pathologic bone marrow and lymph node biopsies. This analysis revealed that VEGF-D is expressed in B cells of the germinal centers, scattered B and T blasts, myeloid progenitors, acute leukemia, several types of non Hodgkin lymphoma, and classical Hodgkin's lymphoma. In normal tissues VEGFR-3 was only expressed in fenestrated capillaries of bone marrow and in lymphatic vessels of lymph nodes, while in VEGF-D expressing tumors newly formed vessels, but not malignant cells, showed high VEGFR-3 expression. These data suggest that VEGF-D could contribute to leukemia and lymphoma growth via the induction of angiogenesis in bone marrow and lymphoid tissues.