Increased vessel density in psoriasis: involvement of lymphatic vessels in the papillary dermis

Morphometric study of lymphangiogenesis in different lesions of psoriasis vulgaris with correlation to disease activity

BACKGROUND AND OBJECTIVES

In the last decades, attention to the role of lymphangiogenesis in psoriasis has been paid. Our study was conducted to evaluate podoplanin-stained lymphatic vessels and the level of lymphangiogenesis in papular psoriatic lesions and psoriatic plaques and ascertain if podoplanin provides any additional prognostic information.

MATERIALS AND METHODS

Number of lymphatic vessels and total lymphatic vessel area were morphometrically analyzed in podoplanin-stained sections, using anti-D2-40, together with the immunohistochemical study of epidermal Ki-67 in psoriasis vulgaris (n = 20) (papules = 7 and plaques = 13) and control skin specimens (n = 20).

RESULTS

The number of lymphatic vessels and total lymphatic vessel area were higher in psoriasis cases compared with normal skin (p = 0.01, p = 0.01 respectively). In psoriatic plaques, the number of lymphatic vessels, total lymphatic vessel area, and epidermal Ki-67 immunoreactivity were higher than in papular lesions (p = 0.002, p = 0.008, and p = 0.01, respectively).

CONCLUSIONS

Psoriasis vulgaris is found to be a lymphangiogenesis-dependent disease, and the lymphatic vascular network is in remodeling and expanding process. Podoplanin may be implicated in the pathogenesis of psoriasis and could be used as a prognostic biomarker for disease severity and progression.

Two Birds, One Stone: Double Hits on Tumor Growth and Lymphangiogenesis by Targeting Vascular Endothelial Growth Factor Receptor 3

Vascular endothelial growth factor receptor 3 (VEGFR3) has been known for its involvement in tumor-associated lymphangiogenesis and lymphatic metastasis. The VEGFR3 signaling is stimulated by its main cognate ligand, vascular endothelial growth factor C (VEGF-C), which in turn promotes tumor progression. Activation of VEGF-C/VEGFR3 signaling in lymphatic endothelial cells (LECs) was shown to enhance the proliferation of LECs and the formation of lymphatic vessels, leading to increased lymphatic metastasis of tumor cells. In the past decade, the expression and pathological roles of VEGFR3 in tumor cells have been described. Moreover, the VEGF-C/VEGFR3 axis has been implicated in regulating immune tolerance and suppression. Therefore, the inhibition of the VEGF-C/VEGFR3 axis has emerged as an important therapeutic strategy for the treatment of cancer. In this review, we discuss the current findings related to VEGF-C/VEGFR3 signaling in cancer progression and recent advances in the development of therapeutic drugs targeting VEGF-C/VEGFR3.

Automated assessment of absolute nailfold capillary number on videocapillaroscopic images: Proof of principle and validation in systemic sclerosis

BACKGROUND

Absolute nailfold capillary number should be a putative biomarker in selected rheumatic diseases but could be time-consuming and not highly repeatable.

OBJECTIVE

To validate an automated software for absolute nailfold capillary number and density evaluation, on NVC images in SSc.

METHODS

An automated software to count nailfold capillary number (AUTOCAPI) had been constructed, through an exploratory image set. Subsequently, application rules have been created to define the ROI in NVC images, through a training images set. The software reliability was assessed through calculation of the ICC between automatic and manual counting, by four independent observers, on the same NVC images.

RESULTS

The following ICC's were obtained per observer, for the patients with SSc (40 images), the healthy (20 images), and the PRP subgroups (20 images), respectively: 0.94, 0.81, and 0.62 (observer 1); 0.94, 0.91, and 0.67 (observer 2); 0.88, 0.56, and 0.64 (observer 3); and 0.88, 0.85, and 0.85 (observer 4).

CONCLUSIONS

The validation of an automated software for measuring absolute nailfold capillary number and density in SSc was achieved. The integration into the pre-existing imaging software should make the assessment of the capillary number in NVC easier, quicker, and standardized.

Lymphatic Vessels, Inflammation, and Immunity in Skin Cancer

Skin is a highly ordered immune organ that coordinates rapid responses to external insult while maintaining self-tolerance. In healthy tissue, lymphatic vessels drain fluid and coordinate local immune responses; however, environmental factors induce lymphatic vessel dysfunction, leading to lymph stasis and perturbed regional immunity. These same environmental factors drive the formation of local malignancies, which are also influenced by local inflammation. Herein, we discuss clinical and experimental evidence supporting the tenet that lymphatic vessels participate in regulation of cutaneous inflammation and immunity, and are important contributors to malignancy and potential biomarkers and targets for immunotherapy.

SIGNIFICANCE

The tumor microenvironment and tumor-associated inflammation are now appreciated not only for their role in cancer progression but also for their response to therapy. The lymphatic vasculature is a less-appreciated component of this microenvironment that coordinates local inflammation and immunity and thereby critically shapes local responses. A mechanistic understanding of the complexities of lymphatic vessel function in the unique context of skin provides a model to understand how regional immune dysfunction drives cutaneous malignancies, and as such lymphatic vessels represent a biomarker of cutaneous immunity that may provide insight into cancer prognosis and effective therapy.

Expression of lymphatic markers and lymphatic growth factors in psoriasis before and after anti-TNF treatment

BACKGROUND

Angiogenesis is an early stage of psoriatic lesion development, but less is known about lymphagiogenesis and its role in the development of psoriasis.

OBJECTIVE

To examine the expression of specific lymphatic markers and lymphatic growth factors in untreated psoriatic skin, in the unaffected skin of patients and skin of healthy volunteers, as well as their alteration after treatment with an anti-TNF agent.

METHODS

Immunohistochemistry for the lymphatic markers D2-40 and LYVE-1, in addition to the VEGF-C and VEGF-D growth factors, was performed in the skin biopsies of psoriatic lesions and adjacent non-psoriatic skin of 19 patients before and after treatment with etanercept, as well as in the skin biopsies of 10 healthy volunteers.

RESULTS

The expressions of D2-40, VEGF-C and VEGF-D on lymphatic vessels underwent statistically significant increases in untreated psoriatic skin compared with non-lesional skin, in contrast to LYVE-1, which did not involve significant increase in expression in psoriatic skin. VEGF-C expression on lymphatic vessels diminished after treatment with etanercept. Moreover VEGF-C and VEGF-D staining on fibroblasts presented with higher expression in lesional skin than in non-lesional adjacent skin.

CONCLUSION

Remodeling of lymphatic vessels possibly occurs during psoriatic lesion development, parallel to blood vessel formation. The exact role of this alteration is not yet clear and more studies are necessary to confirm these results.

Analysis of microvasculature phenotype and endothelial activation markers in skin lesions of lacaziosis (Lobomycosis)

Jorge Lobo's disease is a rare mycosis characterized by chronic inflammation, which causes skin lesions in the absence of visceral dissemination. The disease occurs mainly in hot and humid climates and most cases have been registered in the Brazilian Amazon region. This study investigated possible microvascular alterations in skin lesions caused by infection with Lacazia loboi which may interfere with the clinical progression of the disease. Immunohistochemistry was used to evaluate the density of blood and lymphatic vessels, as well as expression of the cell adhesion molecules ICAM-1, VCAM-1 and E-selectin. The results showed a reduced number of blood (62.66 ± 20.30 vessels/mm(2)) and lymphatic vessels (3.55 ± 5.84 vessels/mm(2)) in Jorge Lobo's disease when compared to control skin (169.66 ± 66.38 blood vessels/mm(2) and 8 ± 2.17 lymphatic vessels/mm(2)). There were a larger number of vessels expressing ICAM-1 (27.58 ± 15.32 vessels/mm(2)) and VCAM-1 (7.55 ± 6.2 vessels/mm(2)). No difference was observed in the expression of E-selectin (4.66 ± 11 vessels/mm(2)). Taken together, the results indicate changes in the local microvasculature which may interfere with the development of an efficient cell-mediated immune response and may explain restriction of the fungus to the site of injury.

Increased permeability of cutaneous lymphatic capillaries and enhanced blood flow in psoriatic plaques

INTRODUCTION

Morphological abnormalities of microvessels are described in psoriasis. However, there are conflicting data as to whether their function is also altered.

OBJECTIVE

Our aim was to study the morphology and function of the lymphatic capillaries of psoriatic skin.

METHODS

Morphology and permeability of initial lymphatics were studied by microlymphography and densitometry in 20 patients. Perfusion was studied by laser Doppler fluxmetry.

RESULTS

Permeability of lymphatics in plaques was increased by 7.6% compared to unafflicted skin (p < 0.001). Lymphatic vessel density and the extension of dye in lymphatic networks were not significantly different between involved and uninvolved areas. Both sites showed a wide range of diameters of lymphatics. The median laser Doppler flux in plaques was increased by 144% (91-380%) compared to unaffected skin (p < 0.001).

CONCLUSIONS

Increased permeability of lymphatics and increased blood flow was demonstrated in vivo in psoriatic skin lesions. These findings may reflect the local inflammatory process and may be used as markers when studying new therapeutic approaches for psoriasis.

B7-h4 expression in human melanoma: its association with patients' survival and antitumor immune response

PURPOSE

Cancers have developed a number of strategies to escape immune responses including the differential expression of costimulatory molecules of the B7 family. B7-H3 and B7-H4 have recently been described in different tumor entities but the relevance for melanoma has not yet been studied so far.

EXPERIMENTAL DESIGN

Using immunohistochemistry, B7-H3 and B7-H4 expression was studied on 29 melanoma lesions. Survival curves and log-rank tests were used to test the association of protein expression with survival. Cell lines were evaluated for B7-H3 and B7-H4 expression by PCR and flow cytometry. Functional T-cell-tumor coculture assays were carried out with in vitro generated tumor transfectants.

RESULTS

B7-H3 and B7-H4 expression was detected in primary tumor lesions (29 of 29 and 28 of 29) and in metastases (28 of 29 and 26 of 29). The numbers of CD68(+) macrophages were significantly lower in patients with low B7-H4 expression, whereas CD8(+) T-cell infiltrates were independent of expression levels. Furthermore, a survival benefit for patients with B7-H4 low expressing melanoma was found, whereas B7-H3 was not associated with any clinical parameter. All 23 melanoma cell lines analyzed expressed B7-H3 and B7-H4 mRNA and protein, but B7-H4 was restricted to intracellular compartments. On silencing of B7-H3 by specific shRNA tumor-associated antigen-specific T cell responses were unaltered. Overexpression of B7-H4 on melanoma cells did not alter the cytotoxicity of different CD8(+) effector cells, but drastically inhibited cytokine production.

CONCLUSIONS

Our study provides for the first time evidence of B7-H4 expression on melanoma cells as a mechanism controlling tumor immunity which is associated with patients' survival.