scholarly journals Simultaneous Upregulation of Elastolytic and Elastogenic Factors Are Necessary for Regulated Collateral Diameter Expansion

2022 ◽  
Vol 8 ◽  
Author(s):  
Elizabeth Andraska ◽  
Nolan Skirtich ◽  
Dylan McCreary ◽  
Rohan Kulkarni ◽  
Edith Tzeng ◽  
...  

Background: During arteriogenesis, outward remodeling of the arterial wall expands luminal diameter to produce increased conductance in developing collaterals. We have previously shown that diameter expansion without loss of internal elastic lamina (IEL) integrity requires both degradation of elastic fibers and LOX-mediated repair. The aim of this study was to investigate the expression of genes involved in remodeling of the extracellular matrix (ECM) using a model of arteriogenesis.Methods: Sprague-Dawley rats underwent femoral artery ligation with distal arteriovenous fistula (FAL + AVF) placement. Profunda femoral arteries (PFA) were harvested for analysis at various time points. Serum desmosine, an amino acid found exclusively in elastin, was evaluated with enzyme-linked immunosorbent assay (ELISA) as a marker of tissue elastolysis. Tissue mRNA isolated from FAL + AVF exposed PFAs was compared to the contralateral sham-operated using qPCR. HCAECs were cultured under low shear stress (8 dyn·s/cm2) for 24 h and then exposed to high shear stress (40 dyn·s/cm2) for 2–6 h. Primers used included FBN-1, FBN-2, Timp-2, LOX-1, Trop-E, Cath-K, Cath-S, MMP-2, MMP-9, FBLN-4, and FBLN-5 and were normalized to GAPDH. mRNA fold changes were quantified using the 2-ΔΔCq method. Comparisons between time points were made with non-parametric ANOVA analysis with Bonferroni adjustment.Results: PFAs showed IEL reorganization during arteriogenesis. Serum desmosine levels are significantly elevated at 2 days and one week, with a return to baseline thereafter (p < 0.01). Expression of ECM structural proteins (FBN-1, FBN-2, FBLN-4, FBLN-5, Tropoelastin, TIMP-2, LOX-1) and elastolytic proteins (MMP-2, MMP-9, Cathepsin S, Cathepsin K) exhibited an early peak (p < 0.05) relative to sham PFAs. After two weeks, expression returned to baseline. HCAECs demonstrated upregulation of FBN-2, FBLN-5, LOX-1 and Trop-E at 4 h of high shear stress, as well as elastolytic protein MMP-2.Conclusions: Elastin degradation begins early in arteriogenesis and is mediated by local upregulation of elastolytic genes. Elastolysis appears to be simultaneously balanced by production of elastic fiber components which may facilitate stabilization of the IEL. Endothelial cells are central to initiation of arteriogenesis and begin ECM remodeling in response to altered shear stress.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4389-4389
Author(s):  
Jing Ling ◽  
Jian Su ◽  
Zhenni Ma ◽  
Changgeng Ruan

Abstract Abstract 4389 Introduction: The W-x-x-W motif is commonly found in the thrombospondin type 1 repeat (TSR) of various extra cellular proteins called TSR super family proteins, including thrombospondins, ADAMTSs, F-spondin and properdin. The W–x–x–W motif is known to bind with heparin, heparan sulfate proteoglycans, collagen and transforming growth factor-β, suggesting functional significance in cell–cell interaction and/or cellular signaling. However, the function of W-x-x-W in ADAMTS13 is unclear. In this study, we investigated the role of the W-x-x-W motif of ADAMTS13. Materials and Methods: We generated a W-x-x-W mutant (W387A) construct of ADAMTS13, and expressed the mutant and the wild-type constructs in HELA cells. Percentage of the protein secretion was defined as the concentration in the culture medium divided by the concentrations in the culture medium and cell lysates, multiplied by 100%. The binding affinity of the mutant or wild-type ADAMTS13 was investigated by enzyme-linked immunosorbent assay. Measurement of ADAMTS13 proteolytic activity toward von Willebrand factor (VWF) multimers was based on the generation of a dimeric 176-kDa fragment resulting from cleavage of VWF at the Y1605-M1606 bond, under denaturing condition and high shear stress condition, analyzed by Western blots. Results: SDS-PAGE gel analysis showed that the W387A mutant was secreted less efficiently relative to the wild-type construct. As for the binding affinity for the VWF multimer, there was no difference between the wild-type and mutant ADAMTS13. The W387A mutant was less active under denaturing condition; the same result was reproduced when FRETS-VWF73 was used as the substrate. However, under high shear stress condition, the mutant was as efficient as the wild-type ADAMTS13. Conclusions: The W–x–x–W motif is necessary for efficient secretion of ADATMS13. Further studies are needed to determine the contribution of the motif to the VWF cleave activity of ADAMTS13. Disclosures: No relevant conflicts of interest to declare.


2018 ◽  
Vol 39 (suppl_1) ◽  
Author(s):  
H Spillemaeker ◽  
A Dupont ◽  
A Kauskot ◽  
A Rauch ◽  
F Vincent ◽  
...  

Hypertension ◽  
2005 ◽  
Vol 45 (4) ◽  
pp. 672-680 ◽  
Author(s):  
Branko Braam ◽  
Remmert de Roos ◽  
Hans Bluyssen ◽  
Patrick Kemmeren ◽  
Frank Holstege ◽  
...  

Fractals ◽  
1999 ◽  
Vol 07 (01) ◽  
pp. 33-39 ◽  
Author(s):  
VINCENT FLEURY ◽  
LAURENT SCHWARTZ

A model is proposed by which the formation of the vascular network in animals proceeds via progressive penetration of the vessel ramification into a capillary mesh, by means of a laplacian growth mechanism of hydrodynamical origin. In this model, the growth of both arteries and veins follows the directions of high shear stress provoked by the blood flow on the endothelial wall of a pre-existing capillary mesh. This process is shown to be identical to the phenomenon of dendritic growth, which is responsible for the formation of such well-known patterns as dendritic crystals, lightning sparks or branching aggregates of bacteria. A number of straightforward consequences of potentially important medical and physiological interests are deduced. These include the natural and spontaneous organization of the arterial and venal trees, the spontaneous and unavoidable tropism of arteries towards veins and vice-versa, the hierarchical character of the vessels and the possibility of computerized prediction of the vascular pattern from the shape of the capillary bed.


2019 ◽  
Vol 20 (20) ◽  
pp. 5040 ◽  
Author(s):  
Thien Ngo ◽  
Keunyoung Kim ◽  
Yiying Bian ◽  
Hakjun Noh ◽  
Kyung-Min Lim ◽  
...  

Antiplatelet agents are important in the pharmacotherapeutic regime for many cardiovascular diseases, including thrombotic disorders. However, bleeding, the most serious adverse effect associated with current antiplatelet therapy, has led to many efforts to discover novel anti-platelet drugs without bleeding issues. Of note, shear stress-induced platelet aggregation (SIPA) is a promising target to overcome bleeding since SIPA happens only in pathological conditions. Accordingly, this study was carried out to discover antiplatelet agents selectively targeting SIPA. By screening various herbal extracts, Paeonia suffruticosa and its major bioactive constituent, paeoniflorin, were identified to have significant inhibitory effects against shear-induced aggregation in human platelets. The effects of paeoniflorin on intraplatelet calcium levels, platelet degranulation, and integrin activation in high shear stress conditions were evaluated by a range of in vitro experiments using human platelets. The inhibitory effect of paeoniflorin was determined to be highly selective against SIPA, through modulating von Willebrand Factor (vWF)-platelet glycoprotein Ib (GP Ib) interaction. The effects of paeoniflorin on platelet functions under high shear stress were confirmed in the ex vivo SIPA models in rats, showing the good accordance with the anti-SIPA effects on human platelets. Treatment with paeoniflorin significantly prevented arterial thrombosis in vivo from the dose of 10 mg/kg without prolonging bleeding time or blood clotting time in rats. Collectively, our results demonstrated that paeoniflorin can be a novel anti-platelet agent selectively targeting SIPA with an improved safety profile.


2016 ◽  
Vol 67 (2) ◽  
pp. 213 ◽  
Author(s):  
Toru Kubo ◽  
Hiroaki Kitaoka

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