Smooth muscle cells PCSK9 knock-out exhibit an impaired response to PDGF stimulation

2016 ◽  
Vol 252 ◽  
pp. e200
Author(s):  
S. Marchianò ◽  
G. Tibolla ◽  
A. Corsini ◽  
A.L. Catapano ◽  
N. Ferri
2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Silvia Castiglioni ◽  
Alessio Vettore ◽  
Lorenzo Arnaboldi ◽  
Laura Calabresi ◽  
Alberto Corsini ◽  
...  

Cells of the artery wall may accumulate free cholesterol and cholesteryl esters becoming foam cells. Up to 50% of foam cells in human lesions originates from smooth muscle cells (SMCs). Arterial SMCs express the ATP binding cassette (ABC) transporter ABCA1 and, upon cholesterol loading, express macrophage markers and a phagocytic activity. To characterize the role of ABCA1 and HDL3 in this transdifferentiation process, we evaluated the phenotypic changes in SMCs isolated from wild type (WT) and ABCA1 knock out (KO) mice and how HDL3 affects these changes. Cholesterol loading causes the downregulation of the expression of SMC markers including ACTA2, alpha-tropomyosin and myosin heavy chain and increases the expression of macrophage-related genes such as CD68, Mac-2, SRB1, MMPs, ABCG1 and ABCA1. HDL3 treatment in WT cells is able to normalize the expression of ACTA2, while the expression of macrophage-related genes is reduced. On the contrary, the preventive effect of HDL3 is completely lost in ABCA1 KO cells. Interestingly, the presence of HDL3 does not differently affect neutral lipid accumulation in WT or ABCA1 KO cells but stimulates phospholipids removal only in WT cells. ApoAI addition does not reverse the phenotypic changes induced by cholesterol not only in KO but also in WT cells. Moreover, cholesterol loading reduces the expression of myocardin, the master SMC specific-transcriptional coactivator involved in SMC differentiation, by up to 55% (p<0.01 vs respective control) in both cell types. HDL3 normalizes myocardin levels in WT cells while it does not have any effect in ABCA1 KO cells. Similar results are obtained evaluating the levels of miR-143/145, which positively regulate myocardin. The basal expression level of KLF4, a myocardin repressor, is almost double in ABCA1 KO cells compared to WT. After cholesterol loading, KLF4 is slightly reduced in WT cells, while its expression is halved in ABCA1 KO cells. HDL3 restores KLF4 to basal levels in KO cells, but it further reduces them in WT cells. These results indicate that HDL3, modulating the miR143/145-myocardin axis in SMC, prevents the cholesterol-induced gene expression modification regardless of its cholesterol unloading capacity and the presence of ABCA1 is required.


2012 ◽  
Vol 5 (1) ◽  
Author(s):  
Caterina Lande ◽  
Claudia Boccardi ◽  
Lorenzo Citti ◽  
Alberto Mercatanti ◽  
Milena Rizzo ◽  
...  

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Morgan Salmon ◽  
Anna Z Fashandi ◽  
Michael D Spinosa ◽  
Ashish K Sharma ◽  
Gary K Owens ◽  
...  

Objective: Zinc-finger protein 148 (ZFP148) plays a profound role in the modulation of aortic aneurysm formation in part via modulation of smooth muscle (SMC) genes. The current study objective was to determine whether smooth muscle specific knock-out of ZFP148 is critical in atherosclerotic lesion formation. Methods: ZFP148 was examined via immunohistochemistry and confocal microscopy in human atherosclerotic lesion samples (n=12/group). 6-8 week male (n=12/group) ZFP flx/flx Myh11 Cre+ ApoE-/-(SMC tamoxifen ZFP148 KO), Myh11 ZFP148 flx/wt Cre+ ApoE-/- and Myh11 ZFP wt/wt Cre+ ApoE-/- underwent tamoxifen injections followed by western diet feeding for either 13 or 25 weeks. A separate set of mice were fed western diet for 18 weeks and then administered tamoxifen injections. Aortic samples were evaluated with histology for α-actin, macrophages, neutrophils, TER119, caspase3, Ki67, picosirus red and movat staining. In vitro ZFP148 was knocked down using siRNA in smooth muscle cells and stimulated with the oxidized phospholipid POVPC. Results: ZFP148 expression was elevated in human atherosclerotic lesion samples and localized to smooth muscle cells. Lesion size was significantly reduced in SMC ZFP148 KO mice compared with controls in 25 week western diet fed mice(p<0.0357). SMC ZFP148 KO demonstrated reduced macrophage, Caspase3, and TER119 staining. Conversely, SMC ZFP148 KO increased SMα-actin coverage. Lesion size was also decreased in mice that were administered tamoxifen injections following 18 weeks of western diet feeding(p<0.0415). There were no significant changes in lesion size at 13 weeks of western diet feeding; however, macrophage staining was decreased. Knock-down of ZFP148 followed by treatment with POVPC attenuated the down-regulation of SM22α, SM-MHC, and SMαA. Knock-down of ZFP148 followed by POVPC treatment also prevented the up-regulation of Bax and BAD in vascular smooth muscle cells. Conclusions: While earlier studies documented a role for ZFP148 in aneurysm disease, the present study suggests that SMC ZFP148 KO attenuates atherosclerotic lesion formation in early and late atherosclerotic disease. ZFP148 represents a key regulator of multiple types of vascular disease.


Author(s):  
Francesca Vacante ◽  
Julie Rodor ◽  
Mukesh K Lalwani ◽  
Amira D Mahmoud ◽  
Matthew Bennett ◽  
...  

Rationale: In the microenvironment of atherosclerotic lesions, vascular smooth muscle cells (vSMCs) switch to a dedifferentiated state but the underlying molecular mechanisms driving this switch are not fully understood. Long noncoding RNAs (lncRNAs) are dysregulated during vascular pathology, but relatively little is known about their involvement in controlling vSMCs function. CARMN is a lncRNA located immediately upstream of the microRNAs (miRNAs) miR-143 and miR-145, both involved in vSMCs function. Objective: We investigated the role of the lncRNA CARMN, independent from miR-143 and miR-145, as potential a regulator of vSMC phenotypes in vitro and the consequences of its loss during the development of atherosclerosis in vivo. We hypothesized that loss of CARMN is a primary event controlling the functional switch towards pro-atherogenic vSMC phenotype and accelerates the development of the plaques in vivo. Methods and Results: Expression of CARMN lncRNA was silenced using GapmeRs in human coronary arterial smooth muscle cells (hCASMCs), revealing that GapmeR-mediated loss of CARMN negatively affects miR-143 and miR-145 miRNA expression. RNA sequencing of CARMN-depleted hCASMCs revealed large transcriptomic changes, associated with vSMC proliferation, migration, inflammation, lipid metabolism and dedifferentiation. The use of miR-143 and miR-145 mimics revealed that CARMN regulates hCASMC proliferation in a miRNA-independent manner. In human and mouse, CARMN and associated miRNAs were downregulated in advanced versus early atherosclerotic lesions. Using a CRISPR-Cas9 knock-out approach, we explored the implications of CARMN depletion during atherosclerosis in vivo. Consistent with in vitro results, the knock-out of CARMN impaired the expression of miR-143 and miR-145 under homeostatic conditions. Importantly, when atherosclerosis was induced in these mice, CARMN knock-out increased the volume, size, pro-inflammatory LGALS3-expressing cells content and altered plaque composition, yielding an advanced phenotype. Conclusions: We identified the early loss of CARMN lncRNA as critical event which primes vSMCs towards a pro-atherogenic phenotype in vitro and accelerates the development of atherosclerosis in vivo.


2006 ◽  
Vol 7 (1) ◽  
Author(s):  
Albrecht Bergner ◽  
Julia Kellner ◽  
Anita Kemp da Silva ◽  
Fernando Gamarra ◽  
Rudolf M Huber

Author(s):  
J.M. Minda ◽  
E. Dessy ◽  
G. G. Pietra

Pulmonary lymphangiomyomatosis (PLAM) is a rare disease occurring exclusively in women of reproductive age. It involves the lungs, lymph nodes and lymphatic ducts. In the lungs, it is characterized by the proliferation of smooth muscle cells around lymphatics in the bronchovascular bundles, lobular septa and pleura The nature of smooth muscle proliferation in PLAM is still unclear. Recently, reactivity of the smooth muscle cells for HMB-45, a melanoma-related antigen has been reported by immunohistochemistry. The purpose of this study was the ultrastructural localization of HMB-45 immunoreactivity in these cells using gold-labeled antibodies.Lung tissue from three cases of PLAM, referred to our Institution for lung transplantation, was embedded in either Poly/Bed 812 post-fixed in 1% osmium tetroxide, or in LR White, without osmication. For the immunogold technique, thin sections were placed on Nickel grids and incubated with affinity purified, monoclonal anti-melanoma antibody HMB-45 (1:1) (Enzo Diag. Co) overnight at 4°C. After extensive washing with PBS, grids were treated with Goat-anti-mouse-IgG-Gold (5nm) (1:10) (Amersham Life Sci) for 1 hour, at room temperature.


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