Neuropilins: structure, function and role in disease

2008 ◽  
Vol 411 (2) ◽  
pp. 211-226 ◽  
Author(s):  
Caroline Pellet-Many ◽  
Paul Frankel ◽  
Haiyan Jia ◽  
Ian Zachary
Keyword(s):  
Molecular Mechanisms ◽  
Cell Types ◽  
Axonal Guidance ◽  
Vascular Endothelial ◽  
Cardiovascular Development ◽  
Functional Responses ◽  
Tumour Cell Lines ◽  
Endothelial Growth Factor ◽  
Different Cell Types

NRPs (neuropilins) are co-receptors for class 3 semaphorins, polypeptides with key roles in axonal guidance, and for members of the VEGF (vascular endothelial growth factor) family of angiogenic cytokines. They lack a defined signalling role, but are thought to mediate functional responses as a result of complex formation with other receptors, such as plexins in the case of semaphorins and VEGF receptors (e.g. VEGFR2). Mutant mouse studies show that NRP1 is essential for neuronal and cardiovascular development, whereas NRP2 has a more restricted role in neuronal patterning and lymphangiogenesis, but recent findings indicate that NRPs may have additional biological roles in other physiological and disease-related settings. In particular, NRPs are highly expressed in diverse tumour cell lines and human neoplasms and have been implicated in tumour growth and vascularization in vivo. However, despite the wealth of information regarding the probable biological roles of these molecules, many aspects of the regulation of cellular function via NRPs remain uncertain, and little is known concerning the molecular mechanisms through which NRPs mediate the functions of their various ligands in different cell types.

The role of neuropilins in cell signalling

2009 ◽  
Vol 37 (6) ◽  
pp. 1171-1178 ◽  
Author(s):  
Ian C. Zachary ◽  
Paul Frankel ◽  
Ian M. Evans ◽  
Caroline Pellet-Many
Keyword(s):  
Molecular Mechanisms ◽  
Cell Signalling ◽  
Cell Types ◽  
Axonal Guidance ◽  
Cardiovascular Development ◽  
Optimal Function ◽  
Intracellular Binding ◽  
Endothelial Growth Factor ◽  
Different Cell Types

NRPs (neuropilins) are receptors for class 3 semaphorins, polypeptides essential for axonal guidance, and for members of the VEGF (vascular endothelial growth factor) family of angiogenic cytokines. While mutant mouse studies show that NRP1 is essential for neuronal and cardiovascular development, little is known concerning the molecular mechanisms through which NRPs mediate the functions of their ligands in different cell types. NRP1 forms complexes with its co-receptors and is required for optimal function, but NRPs lack a clearly defined signalling domain and the role of NRP1 in receptor signalling and the function of the NRP1 cytosolic domain are unclear. Growing evidence indicates, however, that NRP1 plays a selective role in signalling at least in part via its C-terminal domain and interaction with intracellular binding partners.

scholarly journals Exploring the Intracrine Functions of VEGF-A

Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Sophie Wiszniak ◽  
Quenten Schwarz
Keyword(s):  
Cell Growth ◽  
Molecular Mechanisms ◽  
Direct Action ◽  
Cancer Therapeutics ◽  
Cell Types ◽  
Vascular Endothelial ◽  
Signalling Molecule ◽  
Endothelial Growth Factor ◽  
Important Signalling Molecule ◽  
Vegf Signalling

Vascular endothelial growth factor A (VEGF-A or VEGF) is a highly conserved secreted signalling protein best known for its roles in vascular development and angiogenesis. Many non-endothelial roles for VEGF are now established, with the discovery that VEGF and its receptors VEGFR1 and VEGFR2 are expressed in many non-vascular cell-types, as well as various cancers. In addition to secreted VEGF binding to its receptors in the extracellular space at the cell membrane (i.e., in a paracrine or autocrine mode), intracellularly localised VEGF is emerging as an important signalling molecule regulating cell growth, survival, and metabolism. This intracellular mode of signalling has been termed “intracrine”, and refers to the direct action of a signalling molecule within the cell without being secreted. In this review, we describe examples of intracrine VEGF signalling in regulating cell growth, differentiation and survival, both in normal cell homeostasis and development, as well as in cancer. We further discuss emerging evidence for the molecular mechanisms underpinning VEGF intracrine function, as well as the implications this intracellular mode of VEGF signalling may have for use and design of anti-VEGF cancer therapeutics.

scholarly journals Filopodyan: An open-source pipeline for the analysis of filopodia

2017 ◽  
Vol 216 (10) ◽  
pp. 3405-3422 ◽  
Author(s):  
Vasja Urbančič ◽  
Richard Butler ◽  
Benjamin Richier ◽  
Manuel Peter ◽  
Julia Mason ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Dynamic Properties ◽  
Cell Types ◽  
Molecular Heterogeneity ◽  
Interactive Editing ◽  
Motile Cells ◽  
Different Cell Types ◽  
Neuronal Growth Cones

Filopodia have important sensory and mechanical roles in motile cells. The recruitment of actin regulators, such as ENA/VASP proteins, to sites of protrusion underlies diverse molecular mechanisms of filopodia formation and extension. We developed Filopodyan (filopodia dynamics analysis) in Fiji and R to measure fluorescence in filopodia and at their tips and bases concurrently with their morphological and dynamic properties. Filopodyan supports high-throughput phenotype characterization as well as detailed interactive editing of filopodia reconstructions through an intuitive graphical user interface. Our highly customizable pipeline is widely applicable, capable of detecting filopodia in four different cell types in vitro and in vivo. We use Filopodyan to quantify the recruitment of ENA and VASP preceding filopodia formation in neuronal growth cones, and uncover a molecular heterogeneity whereby different filopodia display markedly different responses to changes in the accumulation of ENA and VASP fluorescence in their tips over time.

scholarly journals Lisosan G Protects the Retina from Neurovascular Damage in Experimental Diabetic Retinopathy

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1932 ◽  
Author(s):  
Rosario Amato ◽  
Maria Grazia Rossino ◽  
Maurizio Cammalleri ◽  
Filippo Locri ◽  
Laura Pucci ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Cell Types ◽  
Vascular Endothelial ◽  
Vegf Expression ◽  
Blood Retinal Barrier ◽  
Protective Actions ◽  
Retinal Explants ◽  
Endothelial Growth Factor ◽  
Different Cell Types ◽  
Neurovascular Damage

Lisosan G (LG), a fermented powder obtained from whole grains, is a recognized antioxidant compound that improves the bioactivity and survival of different cell types. The purpose of this study was to investigate whether LG ameliorates both the neural and the vascular damage characterizing early stages of diabetic retinopathy (DR). The effects of LG were studied in cultured explants of mouse retinas challenged with oxidative stress (OS) or in retinas of streptozotocin (STZ)-treated rats. Apoptosis, vascular endothelial growth factor (VEGF) expression, OS markers, blood-retinal barrier (BRB) integrity, and inflammation were assessed, while retinal function was evaluated with electroretinogram (ERG). LG extensively inhibited apoptosis, VEGF expression, and OS both in retinal explants and in STZ rats. In addition, STZ rats treated with LG displayed an almost total BRB integrity, reduced levels of inflammatory markers and a partially restored visual function as evaluated with ERG. In summary, we demonstrated that LG exhibits antioxidant and anti-inflammatory effects that exert powerful protective actions against neural and vascular defects characteristic of DR. Therefore, LG-containing foods or supplements may be considered to implement DR treatments.

scholarly journals Characteristics of tumor-associated endothelial cells derived from glioblastoma multiforme

2006 ◽  
Vol 20 (4) ◽  
pp. E22 ◽  
Author(s):  
Christiana Charalambous ◽  
Thomas C. Chen ◽  
Florence M. Hofman
Keyword(s):  
Endothelial Cells ◽  
Antiangiogenic Therapy ◽  
Cell Types ◽  
Antiangiogenic Agents ◽  
Normal Brain ◽  
Vascular Endothelial ◽  
Phenotypic Characteristics ◽  
Normal Human ◽  
Endothelial Growth Factor

✓ Glioblastomas multiforme (GBMs) are highly vascular brain tumors characterized by abnormal vessel structures in vivo. This finding supports the theory that glioma-associated endothelial cells (ECs) have intrinsically different properties from ECs in normal human brain. Therefore, identification of the functional and phenotypic characteristics of tumor-associated ECs is essential for designing a rational antiangiogenic therapy. The GBM-associated ECs have a large, flat, and veil-like appearance, in contrast to normal ones, which are small and plump. Although the tumor ECs have the typical markers, they proliferate more slowly than these cell types in normal brain. The GBM-associated ECs are resistant to cytotoxic drugs, and they undergo less apoptosis than control cells. Also, GBM-associated ECs migrate faster than controls and constitutively produce high levels of growth factors such as endothelin-1, interleukin-8, and vascular endothelial growth factor. An understanding of these unique characteristics of glioma-associated ECs is important for the development of novel antiangiogenic agents that specifically target tumor-associated ECs in gliomas.

scholarly journals Filopodyan: An Open-Source Pipeline For The Analysis Of Filopodia

2017 ◽  
Author(s):  
Vasja Urbančič ◽  
Richard Butler ◽  
Benjamin Richier ◽  
Manuel Peter ◽  
Julia Mason ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Dynamic Properties ◽  
Cell Types ◽  
Molecular Heterogeneity ◽  
Interactive Editing ◽  
Motile Cells ◽  
Different Cell Types ◽  
Neuronal Growth Cones

Filopodia have important sensory and mechanical roles in motile cells. The recruitment of actin regulators, such as ENA/VASP proteins, to sites of protrusion underlies diverse molecular mechanisms of filopodia formation and extension. We developed Filopodyan ( filopo dia dy namics an alysis) in Fiji and R to measure fluorescence in filopodia and at their tips and bases concurrently with their morphological and dynamic properties. Filopodyan supports high-throughput phenotype characterization as well as detailed interactive editing of filopodia reconstructions through an intuitive graphical user interface. Our highly customizable pipeline is widely applicable, capable of detecting filopodia in four different cell types in vitro and in vivo. We use Filopodyan to show that recruitment of ENA and VASP precedes filopodia formation in neuronal growth cones, and uncover a molecular heterogeneity whereby different filopodia display markedly different responses to changes in the accumulation of ENA and VASP in their tips over time.

scholarly journals Current Advances in Comprehending Dynamics of Regenerating Axons and Axon–Glia Interactions after Peripheral Nerve Injury in Zebrafish

2021 ◽  
Vol 22 (5) ◽  
pp. 2484
Author(s):  
David Gonzalez ◽  
Miguel L. Allende
Keyword(s):  
Nervous System ◽  
Peripheral Nerves ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Time Lapse ◽  
Cell Types ◽  
Regenerative Process ◽  
Time Lapse Microscopy ◽  
Different Cell Types

Following an injury, axons of both the central nervous system (CNS) and peripheral nervous system (PNS) degenerate through a coordinated and genetically conserved mechanism known as Wallerian degeneration (WD). Unlike central axons, severed peripheral axons have a higher capacity to regenerate and reinnervate their original targets, mainly because of the favorable environment that they inhabit and the presence of different cell types. Even though many aspects of regeneration in peripheral nerves have been studied, there is still a lack of understanding regarding the dynamics of axonal degeneration and regeneration, mostly due to the inherent limitations of most animal models. In this scenario, the use of zebrafish (Danio rerio) larvae combined with time-lapse microscopy currently offers a unique experimental opportunity to monitor the dynamics of the regenerative process in the PNS in vivo. This review summarizes the current knowledge and advances made in understanding the dynamics of the regenerative process of PNS axons. By using different tools available in zebrafish such as electroablation of the posterior lateral line nerve (pLLn), and laser-mediated transection of motor and sensory axons followed by time-lapse microscopy, researchers are beginning to unravel the complexity of the spatiotemporal interactions among different cell types during the regenerative process. Thus, understanding the cellular and molecular mechanisms underlying the degeneration and regeneration of peripheral nerves will open new avenues in the treatment of acute nerve trauma or chronic conditions such as neurodegenerative diseases.

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