Browsing by Subject "Lymphangiogenesis"

Now showing 1 - 5 of 5
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    Elevated blood/lymphatic vessel ratio in pterygium and its relationship with vascular endothelial growth factor (VEGF) distribution
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Martín López, Javier; Pérez Rico, Consuelo; García Honduvilla, Natalio; Buján, Julia; Pascual, Gemma
    Introduction. Pterygium is a conjunctival fibrovascular tissue growth on the cornea. The pathogenesis of pterygium involves several factors such as the presence of active angiogenic factors. Expansion of the lymphatic microvasculature has also been hypothesized. This study examines the activity of the angiogenic/lymphangiogenic factor VEGF and the expression of vascular and lymphatic endothelial proteins in pterygia and normal conjunctival tissues. Materials and methods. Primary grade 2 pterygium (n=20) and normal conjunctiva (n=20) biopsies were obtained during surgery after written informed consent. mRNA expression for CD31, podoplanin, and VEGF (isoforms VEGF-A and VEGF-165) were determined by qRT-PCR. Tissue samples were also processed for immunohistochemical techniques to examine the lymphatic and vascular endothelium (anti-D2-40, antiCD31 respectively) and VEGF-A and VEGF-C levels and distribution. Results. VEGF-A gene expression levels failed to differ between the healthy and pterygium tissues. However, expression of its more angiogenic isoform, VEGF-165, was significantly higher in the pterygia. Immunohistochemistry revealed the greater presence of VEGF-A, compared to VEGF-C, in pterygium than conjunctiva, both in blood vessels and extracellular matrix. In addition, pterygia showed higher expression levels of the endothelial junction protein CD31. Lymphatic marker D2-40 expression was slightly augmented in this pathological tissue. The ratio between blood and lymphatic vessel counts was 1.05 in the normal conjunctiva and 3-fold this value in pterygium. Conclusion. In pterygium, while both lymphangiogenesis and angiogenesis take place, the formation of new blood vessels is the most relevant event, correlating with the increased expression of vascular endothelial CD31 and an elevated blood/lymphatic vessel ratio. The presence of high levels of VEGF-A in both vessel networks and extracellular matrix in human pterygium tissue may have a major impact on angiogenesis in this pathological tissue
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    Interleukin-7 (IL-7) and IL-7 receptor (IL-7R) signalling complex in human solid tumours
    (Murcia : F. Hernández, 2003) Al-Rawi, M.A.A.; Mansel, R.E.; Jiang, W.G.
    Interleukin-7 (IL-7) plays an important role in the normal development and maintenance of the human immune system. Its effects are mediated via its receptor, IL-7R. Ligand-receptor engagement results in a cascade of phosphorylation events mediated by various molecules including the Janus kinases (Jak1 and Jak3), PI3-kinase, Stats (signal transducers and activators of transcription) and other molecules. The activation of IL- 7 signalling pathway results in survival, proliferation, differentiation and maturation of haematopoietic cells including B and T lymphocytes. Although the relationship of IL-7 with the development and differentiation of some haematological cancers like leukaemias and lymphomas is well recognised, little is known about it involvement with solid tumours. There are several studies that have revealed IL-7/IL-7R expression in epithelial systems and some human solid epithelial tumours. Furthermore, IL-7 can be produced by some human tumour cells and involved in tumour development and progression. In this review article we have summarised the main biological activities of IL-7 and its downstream signalling complex in relation to some human solid malignancies.
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    Intussusceptive angiogenesis and its counterpart intussusceptive lymphangiogenesis
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Díaz Flores, L.; Gutiérrez, R.; Gayoso, S.; García, M.P.; González-Gómez, M.; Díaz-Flores Jr, L.; Sánchez, R.; Carrasco, J.L.; Madrid Cuevas, Juan Francisco
    Intussusceptive angiogenesis (IA) is currently considered an important alternative and complementary form of sprouting angiogenesis (SA). Conversely, intussusceptive lymphangiogenesis (IL) is in an initial phase of study. We compare their morphofunctional characteristics, since many can be shared by both processes. To that end, the following aspects are considered: A) The concept of IA and IL as the mechanism by which blood and lymphatic vessels split, expand and remodel through transluminal pillar formations (hallmarks of intussusception). B) Terminology and historical background, with particular reference to the group of Burri, including Djonov and Patan, who initiated and developed the vessel intussusceptive concept in blood vessels. C) Incidence in normal (e.g. in the sinuses of developing lymph nodes) and pathologic conditions, above all in vessel diseases, such as dilated veins in hemorrhoidal disease, intravascular papillary endothelial hyperplasia (IPEH), sinusoidal hemangioma, lobular capillary hemangioma, lymphangiomas/lymphatic malformations and vascular transformation of lymph nodes. D) Differences and complementarity between vessel sprouting and intussusception. E) Characteristics of the cover (endothelial cells) and core (connective tissue components) of pillars and requirements for pillar identification. F) Structures involved in pillar formation, including endothelial contacts of opposite vessel walls, interendothelial bridges, merged adjacent capillaries, vessel loops and spilt pillars. G) Structures resulting from pillars with intussusceptive microvascular growth, arborization, remodeling and segmentation (compartmentalization). H) Influence of intussusception in the morphogenesis of vessel tumors/ pseudotumors; and I) Hemodynamic and molecular control of vessel intussusception, including VEGF, PDGF BB, Hypoxia, Notch, Endoglobin and Nitric oxide.
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    Lymphangiogenesis and its role in cancer
    (Murcia : F. Hernández, 2005) Al-Rawi, M.A.A.; Mansel, R.E.; Jiang, W.G.
    In many tumour types, lymphatic vasculature serves as a major route for tumour metastasis. The dissemination of malignant cells to the regional lymph nodes is an early step in the progression of many solid tumours and is an important determinant of prognosis. Lymphangiogenesis (formation of new lymphatic vessels) is thought to be crucial for cancer cells to metastasise to the regional lymph nodes. However research in this important process has been neglected largely due to the lack of molecular markers specific to the lymphatic endothelium. Recently, several specific markers have been identified including LYVE-1, podoplanin and prox-1. Although the biology of lymphangiogeneis, particularly its regulation, is still far from clear, it is now well established that tumours are lymphangiogenic i.e. they could induce the generation of their own lymphatics and metastasise to the regional lymph nodes. It is thought that the interruption of the main signalling pathways involved in this process could help to prevent lymphatic spread of many tumours. Furthermore, understanding the molecular mechanisms in lymphangiogenesis might help to develop new therapeutic strategies against cancer lymphatic spread. Here, we reviewed the literature in regards to the biology of lymphangiogenesis, its molecular regulation, lymphatic markers and the significance in human solid tumours.
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    Quantitative immunohistochemical assessment of blood and lymphatic microcirculation in cutaneous lichen planus lesions
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Výbohová, Desanka; Mellová, Yvetta; Adamicová, Katarína; Adamkov, Marián; Hešková, Gabriela
    Latest advances have brought to light the hypothesis that angiogenesis and lymphangiogenesis are tightly connected to some chronic inflammatory diseases. The present study focuses on immunohistochemical assessment of the quantitative changes in the blood and lymphatic microcirculatory bed in common chronic dermatosis - cutaneous lichen planus. Double immunohistochemistry with CD34 and podoplanin antibodies was used to detect blood and lymphatic endothelium, while anti-human VEGF was used for the observation of a key angiogenesis and lymphangiogenesis inducer. Morphometric analysis was performed with QuickPhoto Micro image analysis software. Results confirmed statistically significant enlargement of both the blood and lymphatic microcirculatory beds. Compared to healthy skin, cutaneous lichen planus lesions revealed 1.6 times enlarged blood microcirculatory bed and 1.8 times enlarged lymphatic microcirculatory bed. Vascular endothelial growth factor (VEGF) expression in lesional skin was significantly higher in the epidermis (19.1 times increase) than in the dermis (10.3 times increase). These findings indicate a tight association of angiogenesis and lymphangiogenesis with the pathogenesis of cutaneous lichen planus.