Smooth muscle cells orchestrate the endothelial cell response to flow and injury

available in PMC 2011 May 25

Bibliographic Details
Main Authors: Balcells-Camps, Mercedes (Contributor), Martorell Lopez, Jordi (Contributor), Olive, Carla (Contributor), Santacana, Marina (Contributor), Chitalia, Vipul C. (Contributor), Cardoso, Angelo A. (Author), Edelman, Elazer R. (Contributor)
Other Authors: Harvard University- (Contributor)
Format: Article
Language:English
Published: American Heart Association, 2012-12-13T21:33:01Z.
Subjects:
Online Access:Get fulltext
LEADER 03091 am a22003613u 4500
001 75728
042 |a dc 
100 1 0 |a Balcells-Camps, Mercedes  |e author 
100 1 0 |a Harvard University-  |e contributor 
100 1 0 |a Balcells-Camps, Mercedes  |e contributor 
100 1 0 |a Martorell Lopez, Jordi  |e contributor 
100 1 0 |a Olive, Carla  |e contributor 
100 1 0 |a Santacana, Marina  |e contributor 
100 1 0 |a Chitalia, Vipul C.  |e contributor 
100 1 0 |a Edelman, Elazer R.  |e contributor 
700 1 0 |a Martorell Lopez, Jordi  |e author 
700 1 0 |a Olive, Carla  |e author 
700 1 0 |a Santacana, Marina  |e author 
700 1 0 |a Chitalia, Vipul C.  |e author 
700 1 0 |a Cardoso, Angelo A.  |e author 
700 1 0 |a Edelman, Elazer R.  |e author 
245 0 0 |a Smooth muscle cells orchestrate the endothelial cell response to flow and injury 
260 |b American Heart Association,   |c 2012-12-13T21:33:01Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/75728 
520 |a available in PMC 2011 May 25 
520 |a Background- Local modulation of vascular mammalian target of rapamycin (mTOR) signaling reduces smooth muscle cell (SMC) proliferation after endovascular interventions but may be associated with endothelial cell (EC) toxicity. The trilaminate vascular architecture juxtaposes ECs and SMCs to enable complex paracrine coregulation but shields SMCs from flow. We hypothesized that flow differentially affects mTOR signaling in ECs and SMCs and that SMCs regulate mTOR in ECs. Methods and Results- SMCs and/or ECs were exposed to coronary artery flow in a perfusion bioreactor. We demonstrated by flow cytometry, immunofluorescence, and immunoblotting that EC expression of phospho-S6 ribosomal protein (p-S6RP), a downstream target of mTOR, was doubled by flow. Conversely, S6RP in SMCs was growth factor but not flow responsive, and SMCs eliminated the flow sensitivity of ECs. Temsirolimus, a sirolimus analog, eliminated the effect of growth factor on SMCs and of flow on ECs, reducing p-S6RP below basal levels and inhibiting endothelial recovery. EC p-S6RP expression in stented porcine arteries confirmed our in vitro findings: Phosphorylation was greatest in ECs farthest from intact SMCs in metal stented arteries and altogether absent after sirolimus stent elution. Conclusions- The mTOR pathway is activated in ECs in response to luminal flow. SMCs inhibit this flow-induced stimulation of endothelial mTOR pathway. Thus, we now define a novel external stimulus regulating phosphorylation of S6RP and another level of EC-SMC crosstalk. These interactions may explain the impact of local antiproliferative delivery that targets SMC proliferation and suggest that future stents integrate design influences on flow and drug effects on their molecular targets. 
520 |a National Institutes of Health (U.S.) (NIH/NIGMS RO1/GM049039) 
520 |a National Institutes of Health (U.S.) (NIH-NIDDK (1K08DK080946)) 
520 |a Fundación Empresas IQS 
520 |a Barcelona Chamber of Commerce 
546 |a en_US 
655 7 |a Article 
773 |t Molecular Cardiology