Extracellular signal-regulated kinase-1 and -2 are both essential for the shear stress-induced human osteoblast proliferation

Bone ◽  
2004 ◽  
Vol 35 (2) ◽  
pp. 525-534 ◽  
Author(s):  
Sonia Kapur ◽  
Shin-Tai Chen ◽  
David J Baylink ◽  
K.-H.William Lau
Keyword(s):  
Shear Stress ◽  
Human Osteoblast ◽  
Osteoblast Proliferation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

scholarly journals Thyroid hormone stimulation of extracellular signal-regulated kinase and cell proliferation in human osteoblast-like cells is initiated at integrin αVβ3

2008 ◽  
Vol 196 (3) ◽  
pp. 509-517 ◽  
Author(s):  
A Scarlett ◽  
M P Parsons ◽  
P L Hanson ◽  
K K Sidhu ◽  
T P Milligan ◽  
...  
Keyword(s):  
Cell Surface ◽  
Thymidine Incorporation ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Cell Surface Receptor ◽  
Human Osteoblast ◽  
Erk Activation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Surface Receptor

The aim of the present study was to examine whether triiodo-l-thyronine (T3) or l-thyroxine (T4) rapidly activated the mitogen-activated protein kinase (MAPK) intracellular signalling cascade in osteoblast-like cells and investigate whether this activation was initiated at the integrin αVβ3 cell surface receptor. Using PCR and western blotting, the expression of integrin αVβ3 mRNA and protein was demonstrated in the human osteoblast-like cell lines MG-63 and SaOS-2. The treatment of MG-63 cells with T3 (10 nM) or T4 (100 nM) for 10 min stimulated extracellular signal-regulated kinase activity (ERK, a component of the MAPK pathway) as determined by fluorescent immunocytochemistry and an immunocomplex activity assay (T3 by 10.7-fold, P<0.01 and T4 by 10.4-fold, P<0.01 compared with control). T3 (10 nM) and T4 (100 nM) also significantly stimulated thymidine incorporation into MG-63 cells by 2.3±0.7-fold (P<0.01) and 2.1±0.1-fold (P<0.05) respectively. To establish whether transient ERK activation via the integrin αVβ3 cell surface receptor mediated these effects, MG-63 cells were pretreated for 30 min with the specific MAPK kinase inhibitor, U0126 (1 μM), or an anti-integrin αVβ3-blocking antibody. Both pretreatments significantly inhibited T3- and T4-stimulated ERK activation and abolished T3-stimulated thymidine incorporation (P<0.01). T4-stimulated incorporation was significantly inhibited from 2.1- to 1.3-fold above control (P<0.05). Thus, our results suggest that T3 and T4 rapidly stimulate ERK activation in MG-63 cells via integrin αVβ3 and that one functional effect of this ERK activation is increased DNA synthesis.

scholarly journals Plasma Membrane Cholesterol Is a Key Molecule in Shear Stress-dependent Activation of Extracellular Signal-regulated Kinase

1998 ◽  
Vol 273 (48) ◽  
pp. 32304-32311 ◽  
Author(s):  
Heonyong Park ◽  
Young-Mi Go ◽  
Patricia L. St. John ◽  
Matthew C. Maland ◽  
Michael P. Lisanti ◽  
...  
Keyword(s):  
Shear Stress ◽  
Plasma Membrane ◽  
Membrane Cholesterol ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Stress Dependent ◽  
Plasma Membrane Cholesterol

scholarly journals Shear stress improves the endothelial progenitor cell function via the CXCR7/ERK pathway axis in the coronary artery disease cases

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hua Zhou ◽  
Qiang Tu ◽  
Yan Zhang ◽  
Hua Qiang Xie ◽  
Qing Yun Shuai ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Shear Stress ◽  
Coronary Artery ◽  
Mononuclear Cells ◽  
Tube Formation ◽  
Endothelial Progenitor ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Artery Disease ◽  
The Impact

Abstract Background Dysfunction in the late Endothelial Progenitor Cells (EPCs) is responsible for endothelial repair in patients with Coronary Artery Disease (CAD), and the shear stress is beneficial for EPCs function. However, the impact of shear stress on the capacity of EPCs in CAD patients has not been elucidated yet. The C-X-C chemokine receptor 7/extracellular signal-regulated kinase (CXCR7)/(ERK) pathways are identified to regulate EPCs function in CAD patients. Here, we hypothesize that shear stress upregulates the CXCR7/ERK pathways, which restore the EPCs function in CAD patients. Methods The human Peripheral Blood Mononuclear Cells (PBMCs) were collected from healthy adults and CAD patients and then used for EPCs cultivation. The Lv-siRNA for human CXCR7 was transfected into induced EPCs isolated from the CAD patients. Meanwhile, the EPCs from CAD patients were subjected to shear stress generated by a biomimetic device. Next, the cell viability, migration, tube formation, and apoptosis were detected by CCK-8, Transwell assay, Matrigel, and flow cytometry, respectively. Also, the CXCR7/ERK pathways in human EPCs were analyzed by Western blotting and qRT-PCR. Result Compared to the EPCs collected from normal adults, the CAD patient-derived EPCs showed reduced in vitro vasculogenic capacity. Also, the level of CXCR7 in CAD patient-derived EPCs was significantly reduced compared to the EPCs of healthy subjects. Meanwhile, the extracellular signal-regulated kinase (ERK), which represents a CXCR7 downstream signaling pathway, had decreased phosphorylation level. The shear stress treatment augmented the CXCR7 expression and also elevated ERK phosphorylation, which is comparable to the up-regulation of CAD patient-derived EPCs function. Further, the small interfering RNA (siRNA)-mediated CXCR7 knockdown diminished the enhanced migration, adhesion, and tube formation capacity of shear stress treated CAD patient-derived EPCs. Conclusion Up-regulation of the CXCR7/ERK pathways by shear stress can be a promising new target in enhancing the vasculogenic ability of CAD patient-derived EPCs.

Caveolin-1 regulates shear stress-dependent activation of extracellular signal-regulated kinase

2000 ◽  
Vol 278 (4) ◽  
pp. H1285-H1293 ◽  
Author(s):  
Heonyong Park ◽  
Young-Mi Go ◽  
Ritesh Darji ◽  
Jong-Whan Choi ◽  
Michael P. Lisanti ◽  
...  
Keyword(s):  
Shear Stress ◽  
Plasma Membrane ◽  
Fluid Shear Stress ◽  
Critical Role ◽  
Signaling Molecules ◽  
Erk Pathway ◽  
Caveolin 1 ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Stress Dependent

Fluid shear stress activates a member of the mitogen-activated protein (MAP) kinase family, extracellular signal-regulated kinase (ERK), by mechanisms dependent on cholesterol in the plasma membrane in bovine aortic endothelial cells (BAEC). Caveolae are microdomains of the plasma membrane that are enriched with cholesterol, caveolin, and signaling molecules. We hypothesized that caveolin-1 regulates shear activation of ERK. Because caveolin-1 is not exposed to the outside, cells were minimally permeabilized by Triton X-100 (0.01%) to deliver a neutralizing, polyclonal caveolin-1 antibody (pCav-1) inside the cells. pCav-1 then bound to caveolin-1 and inhibited shear activation of ERK but not c-Jun NH2-terminal kinase. Epitope mapping studies showed that pCav-1 binds to caveolin-1 at two regions (residues 1–21 and 61–101). When the recombinant proteins containing the epitopes fused to glutathione- S-transferase (GST-Cav1–21 or GST-Cav61–101) were preincubated with pCav-1, only GST-Cav61–101 reversed the inhibitory effect of the antibody on shear activation of ERK. Other antibodies, including m2234, which binds to caveolin-1 residues 1–21, had no effect on shear activation of ERK. Caveolin-1 residues 61–101 contain the scaffolding and oligomerization domains, suggesting that binding of pCav-1 to these regions likely disrupts the clustering of caveolin-1 or its interaction with signaling molecules involved in the shear-sensitive ERK pathway. We suggest that caveolae-like domains play a critical role in the mechanosensing and/or mechanosignal transduction of the ERK pathway.

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