scholarly journals Netrin-1: Focus on its role in cardiovascular physiology and atherosclerosis

2020 ◽  
Vol 9 ◽  
pp. 204800402095957
Author(s):  
Vasco Claro ◽  
Albert Ferro

The netrins form a family of laminin-related proteins which were first described as modulators of cell migration and axonal guidance during fetal development. Netrin-1 is the most extensively studied member of this family and, since its discovery, non-neural roles have been associated with it. Together with its receptors, DCC/neogenin and UNC5, netrin-1 has been shown to be involved in the regulation of angiogenesis, organogenesis, cancer and inflammation. An NF-κB-dependent truncated isoform of netrin-1 has also been shown to be produced in endothelial and some types of cancer cells, which both accumulates in and affects the function of the nucleus. In atherosclerosis, conflicting roles for netrin-1 have been reported on plaque progression via its receptor UNC5b. Whereas endothelial-derived netrin-1 inhibits chemotaxis of leukocytes and reduces the migration of monocytes to the atherosclerotic plaque, netrin-1 expressed by macrophages within the plaque plays a pro-atherogenic role, promoting cell survival, recruiting smooth muscle cells and inhibiting foam cell egress to the lymphatic system. In contrast, there is evidence that netrin-1 promotes macrophage differentiation to an alternative activated phenotype and induces expression of IL-4 and IL-13, while downregulate expression of IL-6 and COX-2. Further work is needed to elucidate the precise roles of the two isoforms of netrin-1 in different cell types in the context of atherosclerosis, and its potential as a putative novel therapeutic target in this disease.

1994 ◽  
Vol 267 (6) ◽  
pp. F987-F997 ◽  
Author(s):  
T. Matsumoto ◽  
C. A. Winkler ◽  
L. P. Brion ◽  
G. J. Schwartz

The mesonephric kidney, precursor to the metanephric kidney, comprises 30-50 nephrons, each with a glomerulus and proximal, distal, and collecting tubules. Although two different cell types have been identified in the mesonephric collecting tubule, no relationship to cells of the metanephric collecting duct has been established. To characterize expression of some of the acid-base-related proteins, we assayed for carbonic anhydrase (CA) activity and performed immunocytochemistry in mesonephroi from 15- to 20-day-old fetal rabbits. From total RNA, we detected expression of CA II and CA IV mRNA. Microdissected proximal and collecting tubules abundantly expressed both CA II and CA IV, at least to the extent observed in mature metanephric proximal tubules and collecting ducts. Histochemistry confirmed the expression of CA activity in these segments; in the collecting tubule, 28% of the collecting tubule cells were CA rich. Most CA-rich cells showed apical H(+)-ATPase and basolateral band 3 anion exchanger staining consistent with the findings in mature H(+)-secreting (alpha) intercalated cells of the metanephric collecting duct. CA-negative cells could be labeled with an antibody that identifies mature metanephric principal cells. Thus the mesonephric collecting tubule has many cells resembling mature alpha-intercalated cells and a majority of cells resembling principal cells. The similarity to the metanephric collecting duct suggests that the lineages of metanephric alpha-intercalated and principal cells may be closely related to those of the mesonephros.


2021 ◽  
Vol 22 (4) ◽  
pp. 1920
Author(s):  
Federica Marzano ◽  
Antonio Rapacciuolo ◽  
Nicola Ferrara ◽  
Giuseppe Rengo ◽  
Walter J. Koch ◽  
...  

G protein-coupled receptors (GPCRs) are the largest family of cell-surface receptors and they are responsible for the transduction of extracellular signals, regulating almost all aspects of mammalian physiology. These receptors are specifically regulated by a family of serine/threonine kinases, called GPCR kinases (GRKs). Given the biological role of GPCRs, it is not surprising that GRKs are also involved in several pathophysiological processes. Particular importance is emerging for GRK5, which is a multifunctional protein, expressed in different cell types, and it has been found located in single or multiple subcellular compartments. For instance, when anchored to the plasma membrane, GRK5 exerts its canonical function, regulating GPCRs. However, under certain conditions (e.g., pro-hypertrophic stimuli), GRK5 translocates to the nucleus of cells where it can interact with non-GPCR-related proteins as well as DNA itself to promote “non-canonical” signaling, including gene transcription. Importantly, due to these actions, several studies have demonstrated that GRK5 has a pivotal role in the pathogenesis of chronic-degenerative disorders. This is true in the cardiac cells, tumor cells, and neurons. For this reason, in this review article, we will inform the readers of the most recent evidence that supports the importance of targeting GRK5 to prevent the development or progression of cancer, cardiovascular, and neurological diseases.


2009 ◽  
Vol 37 (6) ◽  
pp. 1171-1178 ◽  
Author(s):  
Ian C. Zachary ◽  
Paul Frankel ◽  
Ian M. Evans ◽  
Caroline Pellet-Many

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.


2008 ◽  
Vol 19 (5) ◽  
pp. 2179-2192 ◽  
Author(s):  
Susmita Kaushik ◽  
Ashish C. Massey ◽  
Noboru Mizushima ◽  
Ana Maria Cuervo

Three different types of autophagy—macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA)—contribute to degradation of intracellular components in lysosomes in mammalian cells. Although some level of basal macroautophagy and CMA activities has been described in different cell types and tissues, these two pathways are maximally activated under stress conditions. Activation of these two pathways is often sequential, suggesting the existence of some level of cross-talk between both stress-related autophagic pathways. In this work, we analyze the consequences of blockage of macroautophagy on CMA activity. Using mouse embryonic fibroblasts deficient in Atg5, an autophagy-related protein required for autophagosome formation, we have found that blockage of macroautophagy leads to up-regulation of CMA, even under basal conditions. Interestingly, different mechanisms contribute to the observed changes in CMA-related proteins and the consequent activation of CMA during basal and stress conditions in these macroautophagy-deficient cells. This work supports a direct cross-talk between these two forms of autophagy, and it identifies changes in the lysosomal compartment that underlie the basis for the communication between both autophagic pathways.


2008 ◽  
Vol 411 (2) ◽  
pp. 211-226 ◽  
Author(s):  
Caroline Pellet-Many ◽  
Paul Frankel ◽  
Haiyan Jia ◽  
Ian Zachary

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.


Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.


1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.


Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.


2020 ◽  
Vol 19 (4) ◽  
pp. 248-256
Author(s):  
Yangmin Zheng ◽  
Ziping Han ◽  
Haiping Zhao ◽  
Yumin Luo

Conclusion: Stroke is a complex disease caused by genetic and environmental factors, and its etiological mechanism has not been fully clarified yet, which brings great challenges to its effective prevention and treatment. MAPK signaling pathway regulates gene expression of eukaryotic cells and basic cellular processes such as cell proliferation, differentiation, migration, metabolism and apoptosis, which are considered as therapeutic targets for many diseases. Up to now, mounting evidence has shown that MAPK signaling pathway is involved in the pathogenesis and development of ischemic stroke. However, the upstream kinase and downstream kinase of MAPK signaling pathway are complex and the influencing factors are numerous, the exact role of MAPK signaling pathway in the pathogenesis of ischemic stroke has not been fully elucidated. MAPK signaling molecules in different cell types in the brain respond variously after stroke injury, therefore, the present review article is committed to summarizing the pathological process of different cell types participating in stroke, discussed the mechanism of MAPK participating in stroke. We further elucidated that MAPK signaling pathway molecules can be used as therapeutic targets for stroke, thus promoting the prevention and treatment of stroke.


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