Abstract 160: Tuberosis Sclerosis Complex 1 Mediated Neointima Formation and Arterial Thrombosis Following Vascular Injury

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Eo Jin Kim ◽  
Yong-Joo Ahn ◽  
Maya Hwewon Kim ◽  
Hyung-Hwan Kim
Keyword(s):  
Smooth Muscle ◽  
Carotid Artery ◽  
Vascular Injury ◽  
Knockout Mice ◽  
Arterial Thrombosis ◽  
Immunoblot Analysis ◽  
Arterial Injury ◽  
Conditional Knockout ◽  
Neointima Formation

Objectives: Vascular injury and thrombosis are main leading causes of cardiovascular diseases. Tuberous sclerosis complex (TSC) is a genetic disorder caused by heterozygous mutations in either of two genes, TSC1 and TSC2. Although role of TSCs has been implicated in cardiovascular diseases, the tissue- and isoform-specific roles of TSCs in the vascular response to injury are not known. Methods and Results: To determine the role of TSC1 in arterial injury and thrombosis, we generated vascular smooth muscle cell-specific TSC1 conditional knockout mice (TSC1SM22-/-) by crossing vascular smooth muscle cell-specific Cre (SM22Cre) mice with TSC1flox/flox mice and performed carotid artery ligation in haploinsufficient TSC1 conditional knockout mice (TSC1SM22+/-) compared with that of WT or haploinsufficient TSC2 knockout mice (TSC2+/-). Acute carotid artery occlusion was investigated by 5% ferric chloride injury. Arterial thrombosis and neointima formation were measured at 14 days after arterial ligation. Expression of proteins was observed by immunoblot analysis. The neointima formation was significantly increased in TSC1SM22+/- mice (intimal thickness/medial thickness ratio; 1.14 ± 0.14, p<0.001) compared with that of WT mice (0.13 ± 0.03). Two weeks after arterial injury, arterial thrombus area was increased in TSC1SM22+/- mice (thrombus area/luminal area ratio; 72.1 ± 4.4, p<0.001) compared with that of WT mice (0.1 ± 0.0) but there are no significant effect in acute arterial thrombosis induced by ferric chloride. Loss of TSC1 and hyper-activation of mammalian target of rapamycin complex 1 including mTOR and S6 proteins were observed by immunoblot analysis of carotid artery tissue lysates of TSC1SM22+/- mice compared with that of WT. Conclusion: These findings suggest that regulation of TSC1 and mTOR might be useful for therapeutic intervention in vascular injury and thrombosis.

Abstract 94: Ca 2 +/calmodulin-dependent Protein Kinase II ? Gene Deletion Enhances Vascular Remodeling in Response to Injury

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Fatima Zahra Saddouk ◽  
Miao Jiang ◽  
LiYan Sun ◽  
John J Schwarz ◽  
Harold A Singer
Keyword(s):  
Protein Kinase ◽  
Carotid Artery ◽  
Knockout Mice ◽  
Conditional Knockout ◽  
Brdu Incorporation ◽  
Proliferation Index ◽  
Neointima Formation ◽  
Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein

Differentiated vascular smooth muscle (VSM) cells undergo phenotypic switching following injury or primary cell culture. This process includes changes in expression of ion channels, proteins involved in intracellular Ca 2+ homeostasis, as well as changes in Ca 2+ signal effectors. Our previous studies showed that the delta2 isoform of the multifunctional serine/threonine protein kinase Ca 2+ /calmodulin-dependent protein kinase II (CaMKIIδ 2 or CaMKIIδc), was up-regulated in rat carotid artery VSM following balloon injury and contributed positively to cell proliferation, migration and neointima formation. Conversely, CaMKII γ gene isoforms are down-regulated following vascular injury in rats, with as yet unknown functional consequences. We hypothesized that CaMKIIγ expression opposes the vasculoproliferative response promoted by CaMKIIδ. To test this, we generated CaMKIIγ conditional knockout mice by crossing CaMKIIγ loxp/loxp mice with a SM22α (transgelin)-Cre line. Efficient deletion of CaMKIIγ was confirmed in VSM and heart with no compensatory increases in CaMKIIδ expression or observable effects on mouse development, expression of VSMC differentiation marker genes or vascular morphology. Carotid artery ligation-induced neointima formation was markedly enhanced in CaMKIIγ conditional knockout mutant mice compared to littermate controls (Neointima/media area ratios: 0.52 ± 0.20, n=8 vs. 0.03±0.03, n=7) 3 weeks post-ligation with a nearly 2-fold increase in vascular wall proliferation index (0.09±0.006, n=6 vs. 0.05±0.009, n=6) and no change in apoptosis index. CaMKIIγ protein expression is down-regulated following primary culture of aortic VSM. Ectopic re-expression of CaMKIIγ in cultured VSMC from control or global CaMKIIδ-/- knockout mice resulted in a significant reduction in proliferation rates as measured by cell counting and BrdU incorporation and cell migration as assessed by scratch wounding. We conclude from these studies that CaMKIIγ and δ-isoforms have non-equivalent functions in VSM, and specifically, that CaMKIIγ isoforms inhibit the vasculoproliferative response.

Vascular ligation response is independent of p107: stressing the role of the related p130

2003 ◽  
Vol 285 (2) ◽  
pp. H915-H918 ◽  
Author(s):  
Jürgen R. Sindermann ◽  
Christiane Köbbert ◽  
Florian Bauer ◽  
Adriane Skaletz-Rorowski ◽  
Helge Hohage ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Vascular Injury ◽  
Femoral Artery ◽  
Arterial Injury ◽  
Injury Response ◽  
Artery Ligation ◽  
Wall Area ◽  
Carotid Artery Ligation ◽  
Electric Injury

Recent studies have revealed the role of the pRb family members pRb and p130 in the response to vascular injury. We evaluated the arterial injury response in the absence of p107, a protein that shares a high degree of homology with the injury-controlling p130. Carotid artery ligation and perivascular electric injury of the femoral artery were applied to p107 knockout (p107 –/–) mice, and morphometric analysis was performed 3 wk after ligation and electric injury. Arterial vessels of p107 –/– mice were indistinguishable from controls under basal conditions. After carotid artery ligation the p107 –/– mice ( n = 7) did not display an enhanced ligation response compared with controls ( n = 9), which was studied over a distance of ∼450 μm proximal and ∼200 μm distal from the ligation site, with regard to vessel wall area, neointima area, and lumen area. Corresponding with this, morphometric data obtained from the perivascular electric injury of the femoral artery confirmed the lack of enhanced ligation and injury response in the absence of p107. We conclude that the pRb family member p107 is not a key regulator in vascular injury response. These data, in conjunction with previously reported results, indicate that the control of vascular injury response is not a redundant feature of pRb proteins but primarily specific for p130. Further studies on functional domains of p130 and p107 will help to resolve the pathways in vascular injury response.

scholarly journals Adenosine kinase is critical for neointima formation after vascular injury by inducing aberrant DNA hypermethylation

2020 ◽  
Author(s):  
Yong Wang ◽  
Yiming Xu ◽  
Siyuan Yan ◽  
Kaixiang Cao ◽  
Xianqiu Zeng ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Injury ◽  
Arterial Injury ◽  
Adenosine Kinase ◽  
Neointima Formation ◽  
Dna Hypermethylation ◽  
Vsmc Proliferation ◽  
Pharmacological Inhibition ◽  
Klf4 Expression ◽  
Smooth Muscle Proliferation

Abstract Aims Adenosine receptors and extracellular adenosine have been demonstrated to modulate vascular smooth muscle cell (VSMC) proliferation and neointima formation. Adenosine kinase (ADK) is a major enzyme regulating intracellular adenosine levels but is function in VSMC remains unclear. Here, we investigated the role of ADK in vascular injury-induced smooth muscle proliferation and delineated the mechanisms underlying its action. Methods and results We found that ADK expression was higher in the neointima of injured vessels and in platelet-derived growth factor-treated VSMCs. Genetic and pharmacological inhibition of ADK was enough to attenuate arterial injury-induced neointima formation due to inhibition of VSMC proliferation. Mechanistically, using infinium methylation assays and bisulfite sequencing, we showed that ADK metabolized the intracellular adenosine and potentiated the transmethylation pathway, then induced the aberrant DNA hypermethylation. Pharmacological inhibition of aberrant DNA hypermethylation increased KLF4 expression and suppressed VSMC proliferation as well as the neointima formation. Importantly, in human femoral arteries, we observed increased ADK expression and DNA hypermethylation as well as decreased KLF4 expression in neointimal VSMCs of stenotic vessels suggesting that our findings in mice are relevant for human disease and may hold translational significance. Conclusion Our study unravels a novel mechanism by which ADK promotes VSMC proliferation via inducing aberrant DNA hypermethylation, thereby down-regulating KLF4 expression and promoting neointima formation. These findings advance the possibility of targeting ADK as an epigenetic modulator to combat vascular injury.

scholarly journals Role of FOXM1 in vascular smooth muscle cell survival and neointima formation following vascular injury

Heliyon ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. e04028
Author(s):  
Sarah Franco ◽  
Amelia Stranz ◽  
Fiona Ljumani ◽  
Go Urabe ◽  
Mirnal Chaudhary ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Cell Survival ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Vascular Injury ◽  
Neointima Formation

scholarly journals Repetitive Hypoglycemia Increases Circulating Adrenaline Level with Resultant Worsening of Intimal Thickening After Vascular Injury in Male Goto-Kakizaki Rat Carotid Artery

Endocrinology ◽  
2014 ◽  
Vol 155 (6) ◽  
pp. 2244-2253 ◽  
Author(s):  
Eisuke Yasunari ◽  
Tomoya Mita ◽  
Yusuke Osonoi ◽  
Kosuke Azuma ◽  
Hiromasa Goto ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Carotid Artery ◽  
Vascular Injury ◽  
Insulin Treatment ◽  
Diabetes Management ◽  
Nuclear Antigen ◽  
Neointima Formation ◽  
Intimal Thickening ◽  
Balloon Injury ◽  
Gk Rats

Hypoglycemia associated with diabetes management is a potential risk for cardiovascular diseases. However, the effect of hypoglycemic episodes including a surge of sympathetic activity on the progression of neointima formation after vascular injury remains largely unknown. In this study, insulin was injected intraperitoneally into nonobese diabetic Goto-Kakizaki (GK) rats, once every 3 days for 4 weeks after balloon injury of carotid artery to induce hypoglycemia. Then, we evaluated balloon injury-induced neointima formation. Insulin treatment enhanced neointima formation and increased the number of proliferating cell nuclear antigen (PCNA)-positive cells in the carotid artery. Injection of glucose with insulin prevented hypoglycemia and abrogated intimal thickening. Also, bunazosin, an α1 adrenergic receptor antagonist, prevented intimal thickening and accumulation of PCNA-positive cells induced by insulin treatment despite the presence of concomitant hypoglycemia and high adrenaline levels. Incubation of cultured smooth muscle cells with adrenaline resulted in a significant increase in their proliferation and G0/G1 to S phase progression, which was associated with activation of extracellular signal-regulated kinase, enhanced expression of cell cycle regulatory molecules such as cyclin D1, and cyclin E, and phosphorylation of retinoblastoma protein. These adrenaline-induced effects were abrogated by bunazosin. Our data indicated that increased adrenaline induced by repetitive hypoglycemia promotes intimal thickening and smooth muscle cell proliferation after endothelial denudation in GK rats.

scholarly journals Vascular smooth muscle–derived tissue factor is critical for arterial thrombosis after ferric chloride–induced injury

Blood ◽  
2009 ◽  
Vol 113 (3) ◽  
pp. 705-713 ◽  
Author(s):  
Li Wang ◽  
Christine Miller ◽  
Robert F. Swarthout ◽  
Mohan Rao ◽  
Nigel Mackman ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Tissue Factor ◽  
Ferric Chloride ◽  
Arterial Thrombosis ◽  
Critical Role ◽  
Arterial Injury ◽  
Aortic Media ◽  
Deficient Mice

Abstract Tissue factor (TF) initiates coagulation, regulates hemostasis, and plays a critical role in mediating arterial thrombosis. TF is up-regulated in vascular smooth muscle cells (VSMCs) in atherosclerosis and arterial injury. To examine the biologic role of VSMC-derived TF, we crossed TFflox/flox mice with SM22αCre+/− mice. TF mRNA and activity were decreased in the aortic media of TF-deficient mice by 96% and 94.8%, respectively. There were no differences in TF activity measured in plasma or concentrated microparticles. TF-deficient mice were generated with the expected frequency, showed no evidence of bleeding or increased mortality, and had similar activated partial thromboplastin and tail vein bleeding times. Thrombus-mediated flow reduction in response to ferric chloride injury of the carotid arteries was significantly attenuated in VSMC-specific TF-deficient. Stable occlusion was seen in 11 of 12 wild-type mice, but in only 6 of 16 VSMC-specific TF-deficient mice (P = .001). These data suggest that VSMC-derived TF is critical in a macrovascular model of arterial thrombosis. This mouse model should be valuable in determining the contribution of VSMC-derived TF in other TF-mediated phenomena, such as restenosis.

Antiplatelet Effect of FK633, a Platelet Glycoprotein Ilb/IIIa Antagonist, on Thrombus Formation and Vascular Patency after Thrombolysis in the Injured Hamster Carotid Artery

1997 ◽  
Vol 77 (03) ◽  
pp. 562-567 ◽  
Author(s):  
Takehiro Kaida ◽  
Hiroyuki Matsuno ◽  
Masayuki Niwa ◽  
Osamu Kozawa ◽  
Hideo Miyata ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Carotid Artery ◽  
Vascular Injury ◽  
Bleeding Time ◽  
Thrombus Formation ◽  
Separate Experiment ◽  
Platelet Glycoprotein ◽  
Neointima Formation ◽  
Vascular Patency ◽  
Injured Artery

SummaryThe antithrombotic and restenosis-preventing effects of FK633, an inhibitor of platelet aggregation via binding to the glycoprotein (GP) Ilb/IIIa receptor, were studied. IC50 value of FK633 against platelet aggregation ex vivo induced by 2.5 |iM adenosine diphosphate (ADP) was 5.4 X 10"7 M as determined using hamster platelet rich plasma. The inhibitory effect was also investigated in vivo on thrombus formation at the carotid arterial wall injured by a modified catheter. As a control, the left carotid artery was injured and the time required to develop a thrombotic occlusion (3.9 ±1.1 min, mean ± S.E.M., n = 18) was determined. Then, the right carotid artery of the same animal was injured while a continuous intravenous (i.v.) infusion of FK633 was administered at doses of 0 (saline), 0.1,0.3 or 1.0 mg/kg/h. The time to occlusion was dose-dependently prolonged. In a separate experiment, 10% of the total tPA dose (0.52 mg/kg) was injected into the injured artery as a bolus and the remaining was infused i.v. at a constant rate for 30 min. When FK633 (0.3 or 1.0 mg/kg/h) was infused together with tPA, late patency of the reperfused artery was much improved as compared with that of treatment with tPA alone. Bleeding time, measured at the end of the tPA infusion, was markedly prolonged when the higher dose of FK633 (1.0 mg/kg/h) was coadministered, however coadministration of the lower dose of FK633 (0.3 mg/kg/h) was almost without prolongation on the bleeding time, despite a significant effect on the vascular patency after thrombolysis. Next, neointima formation was evaluated 2 weeks after the vascular injury. When FK633 (0.3 mg/kg/h) was continuously infused i. v. by an implanted osmotic pump for 3,7 or 14 days after the vascular injury, the neointimal area formation was significantly suppressed in the treatment groups for 7 or 14 days. These findings suggest that FK633 inhibits platelet activation in the injured artery and improves vascular patency after thrombolysis with tPA with a concomitant suppression of neointima formation.

Functional role of miRNA-34A in smooth muscle cell functions and neointima formation

2016 ◽  
Vol 244 ◽  
pp. e3-e4 ◽  
Author(s):  
F. Yang ◽  
Q. Chen ◽  
G. Wen ◽  
C. Zhang ◽  
L.A. Luong ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Functional Role ◽  
Neointima Formation ◽  
Cell Functions
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