The biophysical property of A549 cells transferred by VEGF-D

Beyond vessels: unraveling the impact of VEGFs on neuronal functions and structure

Neurons rely on the bloodstream for essential nutrients and oxygen, which is facilitated by an intricate coupling of the neuronal and vascular systems. Central to this neurovascular interaction is the vascular endothelial growth factor (VEGF) family, a group of secreted growth factors traditionally known for their roles in promoting endothelial cell proliferation, migration, and survival in the cardiovascular and lymphatic systems. However, emerging evidence shows that VEGFs also play indispensable roles in the nervous system, extending beyond their canonical angiogenic and lymphangiogenic functions. Over the past two decades, VEGFs have been found to exert direct effects on neurons, influencing key aspects of neuronal function independently of their actions on vascular cells. In particular, it has become increasingly evident that VEGFs also play crucial functions in the development, regulation, and maintenance of neuronal morphology. Understanding the roles of VEGFs in neuronal development is of high scientific and clinical interest because of the significance of precise neuronal morphology for neural connectivity and network function, as well as the association of morphological abnormalities with neurological and neurodegenerative disorders. This review begins with an overview of the VEGF family members, their structural characteristics, receptors, and established roles in vasculature. However, it then highlights and focuses on the exciting variety of neuronal functions of VEGFs, especially their crucial role in the development, regulation, and maintenance of neuronal morphology.

VEGFD signaling balances stability and activity-dependent structural plasticity of dendrites

Mature neurons have stable dendritic architecture, which is essential for the nervous system to operate correctly. The ability to undergo structural plasticity, required to support adaptive processes like memory formation, is still present in mature neurons. It is unclear what molecular and cellular processes control this delicate balance between dendritic structural plasticity and stabilization. Failures in the preservation of optimal dendrite structure due to atrophy or maladaptive plasticity result in abnormal connectivity and are associated with various neurological diseases. Vascular endothelial growth factor D (VEGFD) is critical for the maintenance of mature dendritic trees. Here, we describe how VEGFD affects the neuronal cytoskeleton and demonstrate that VEGFD exerts its effects on dendrite stabilization by influencing the actin cortex and reducing microtubule dynamics. Further, we found that during synaptic activity-induced structural plasticity VEGFD is downregulated. Our findings revealed that VEGFD, acting on its cognate receptor VEGFR3, opposes structural changes by negatively regulating dendrite growth in cultured hippocampal neurons and in vivo in the adult mouse hippocampus with consequences on memory formation. A phosphoproteomic screening identified several regulatory proteins of the cytoskeleton modulated by VEGFD. Among the actin cortex-associated proteins, we found that VEGFD induces dephosphorylation of ezrin at tyrosine 478 via activation of the striatal-enriched protein tyrosine phosphatase (STEP). Activity-triggered structural plasticity of dendrites was impaired by expression of a phospho-deficient mutant ezrin in vitro and in vivo. Thus, VEGFD governs the equilibrium between stabilization and plasticity of dendrites by acting as a molecular brake of structural remodeling.

CCR7 promote lymph node metastasis via regulating VEGF-C/D-R3 pathway in lung adenocarcinoma

Lymph node metastasis is still an important issue in metastatic process of lung adenocarcinoma. C-C chemokine receptor 7 (CCR7) has been proved to be closely associated with the metastasis of lung adenocarcinoma, and the mechanism is poorly understood. In order to investigate the relationship between CCR7 and lymph node metastasis in lung adenocarcinoma, and to explore the role of CCR7 in treating lung adenocarcinoma, 40 clinical specimens were collected to define the relationship between CCR7 and lymph node metastasis in lung adenocarcinoma by immunohistochemistry. The siRNA was used to suppress CCR7 expression in A549 cells. The scratch test, transwell test, qRT-PCR, western blot, flow cytometry and immunofluorescence were used to investigate the lymph node metastasis-related function of CCR7 in vitro. The athymic mice subcutaneous injection was used to research lung adenocarcinoma formation in vivo. Clinical case studies show that higher expression of CCR7 in lung adenocarcinoma tissues was associated with a higher lymph node metastasis. Inhibition of expression of CCR7 can reduce the migration and invasion and suppress the expression of VEGF-C, VEGF-D and VEGF-R3 in vitro and in vivo. Moreover, CCR7 silence also suppressed WNT and p-ERK pathways in vitro. All the results indicate that CCR7 can promote lymph node metastasis in lung adenocarcinoma by regulating VEGF-C/D-R3 pathway. Thus CCR7 is proposed to be a potential prediction for poor prognosis of lung adenocarcinoma, and a therapeutic target for lymph node metastasis.