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ABSTRACT: Prostacyclin and its stable analogs play an important vascular protective role by promoting angiogenesis, but their role in arteriolar growth is unclear. Here, we examined the effect of prostacyclin stable analog carbaprostacyclin on arteriolar growth in mouse hindlimb ischemia. Using an osmotic-controlled release system to continuously deliver carbaprostacyclin or saline (control) to ischemic mouse hindlimbs for up to 14 days, we found that blood perfusion was significantly better at 7 and 14 days in carbaprostacyclin-treated mice than in saline-treated mice. Microscopic examination of the microvasculature showed more morphological signs of arteriolar formation in carbaprostacyclin- versus saline-treated legs. A double-blind, quantitative microcomputed tomography analysis indicated that carbaprostacyclin-treated legs had markedly increased vascular volume and small- to medium-sized vessel numbers that correspond to decreased vessel separation. A proteome profiler antibody array demonstrated that carbaprostacyclin-treated ischemic muscles secreted significantly higher amounts of acidic fibroblast growth factor and other chemokines. Conditioned media containing those secreted factors promoted smooth muscle cell growth and migration. Additionally, increased acidic fibroblast growth factor protein levels were detected in smooth muscle cells and skeletal myotubes at different time periods after carbaprostacyclin treatment. Furthermore, the selective peroxisome proliferation-activated receptor β/δ antagonist significantly suppressed carbaprostacyclin-induced acidic fibroblast growth factor protein production. Collectively, our data provide the first morphological and molecular evidence that local delivery of carbaprostacyclin promotes vascular growth in hindlimb ischemia, and that peroxisome proliferation-activated receptor β/δ signaling plays a critical role in inducing acidic fibroblast growth factor expression.
Hypertension 03/2013; · 6.21 Impact Factor
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Qi Liu,
Yutao Xi,
Toya Terry,
Shui-Ping So,
Anita Mohite,
Jia Zhang,
Geru Wu,
Xiaobing Liu,
Jie Cheng,
Ke-He Ruan,
James T Willerson,
Richard A F Dixon
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ABSTRACT: Prostacyclin (PGI2) is a potent vasodilator and important mediator of vascular homeostasis; however, its clinical use is limited because of its short (<2-min) half-life. Thus, we hypothesize that the use of engineered endothelial progenitor cells (EPCs) that constitutively secrete high levels of PGI2 may overcome this limitation of PGI2 therapy. A cDNA encoding COX-1-10aa-PGIS, which links human cyclooxygenase-1 (COX-1) to prostacyclin synthase (PGIS), was delivered via nucleofection into outgrowth EPCs derived from rat bone marrow mononuclear cells. PGI2-secreting strains (PGI2-EPCs) were established by continuous subculturing of transfected cells under G418 selection. Genomic PCR, RT-PCR, and Western blot analyses confirmed the overexpression of COX-1-10aa-PGIS in PGI2-EPCs. PGI2-EPCs secreted significantly higher levels of PGI2 in vitro than native EPCs (P < 0.05) and showed higher intrinsic angiogenic capability; conditioned medium (CM) from PGI2-EPCs promoted better tube formation than CM from native EPCs (P < 0.05). Cell- and paracrine-mediated in vitro angiogenesis was attenuated when COX-1-10aa-PGIS protein expression was knocked down. Whole-cell patch-clamp studies showed that 4-aminopyridine-sensitive K(+) current density was increased significantly in rat smooth muscle cells (rSMCs) cocultured under hypoxia with PGI2-EPCs (7.50 ± 1.59 pA/pF; P < 0.05) compared with rSMCs cocultured with native EPCs (3.99 ± 1.26 pA/pF). In conclusion, we successfully created EPC strains that overexpress an active novel enzyme resulting in consistent secretion of PGI2. PGI2-EPCs showed enhanced intrinsic proangiogenic properties and provided favorable paracrine-mediated cellular protections, including promoting in vitro angiogenesis of native EPCs and hyperpolarization of SMCs under hypoxia.
Journal of Cellular Physiology 09/2011; 227(7):2907-16. · 3.87 Impact Factor
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ABSTRACT: Prostacyclin (PGI(2)) and its analogues protect from cardiovascular disease through pleiotropic effects such as vasodilation, inhibition of platelet aggregation, leukocyte adhesion, and vascular smooth muscle cell (VSMC) proliferation. Additionally, prostacyclin synthase (PGIS) and PGI(2) also possess anti-cancer properties. As of late (2009-2010), numerous studies have identified the deleterious side-effects of chemotherapy on the cardiovascular system, which have been deemed as a serious clinical issue. Cardiomyocyte damage, induced by oxidative stress, is one of the clinical consequences caused by routine cancer chemotherapy. Previous studies indicate iloprost, a PGI(2) analogue, can protect against doxorubicin-induced (DOX) cardiomyocyte injury in vitro and in vivo without compromising tumor suppression. Therefore, we hypothesize PGI(2) can be used as a cardioprotective supplement to attenuate the damaging cardiac effects caused by the traditional cancer chemotherapy regimen.
Medical Hypotheses 02/2011; 76(5):695-6. · 1.39 Impact Factor
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ABSTRACT: Cell-based therapy shows promise in treating peripheral arterial disease (PAD); however, the optimal cell type and long-term efficacy are unknown. In this study, we identified a novel subpopulation of adult progenitor cells positive for CD34 and M-cadherin (CD34⁺/M-cad⁺ BMCs) in mouse and human bone marrow. We also examined the long-lasting therapeutic efficacy of mouse CD34⁺/M-cad⁺ BMCs in restoring blood flow and promoting vascularization in an atherosclerotic mouse model of PAD.
Colony-forming cell assays and flow cytometry analysis showed that CD34⁺/M-cad⁺ BMCs have hematopoietic progenitor properties. When delivered intra-arterially into the ischemic hindlimbs of ApoE⁻/⁻ mice, CD34⁺/M-cad⁺ BMCs alleviated ischemia and significantly improved blood flow compared with CD34⁺/M-cad⁻ BMCs, CD34⁻/M-cad⁺ BMCs, or unselected BMCs. Significantly more arterioles were seen in CD34⁺/M-cad⁺ cell-treated limbs than in any other treatment group 60 days after cell therapy. Furthermore, histologic assessment and morphometric analyses of hindlimbs treated with GFP⁺ CD34⁺/M-cad⁺ cells showed that injected cells incorporated into solid tissue structures at 21 days. Confocal microscopic examination of GFP⁺ CD34⁺/M-cad⁺ cell-treated ischemic legs followed by immunostaining indicated the vascular differentiation of CD34⁺/M-cad⁺ progenitor cells. A cytokine antibody array revealed that CD34⁺/M-cad⁺ cell-conditioned medium contained higher levels of cytokines in a unique pattern, including bFGF, CRG-2, EGF, Flt-3 ligand, IGF-1, SDF-1, and VEGFR-3, than did CD34⁺/M-cad⁻ cell-conditioned medium. The proangiogenic cytokines secreted by CD34⁺/M-cad⁺ cells induced oxygen- and nutrient-depleted endothelial cell sprouting significantly better than CD34⁺/M-cad⁻ cells during hypoxia.
CD34⁺/M-cad⁺ BMCs represent a new progenitor cell type that effectively alleviates hindlimb ischemia in ApoE⁻/⁻ mice by consistently improving blood flow and promoting arteriogenesis. Additionally, CD34⁺/M-cad⁺ BMCs contribute to microvascular remodeling by differentiating into vascular cells and releasing proangiogenic cytokines and growth factors.
PLoS ONE 01/2011; 6(6):e20673. · 4.09 Impact Factor
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ABSTRACT: Bone marrow cell therapy promotes angiogenesis, but the cellular fate of bone marrow cells (BMCs) in the absence of immunosuppressant interventions is unclear. We created a model of severe hind limb ischemia to address whether BMCs form new blood vessels or differentiate into other tissues.
After ligating the common femoral artery in ApoE knockout mice, we injected either phosphate buffered saline (PBS) or 5 x 10(7) adult unfractionated BMCs obtained from green fluorescent protein-positive mice. Laser Doppler imaging of the ischemic limbs revealed that intra-arterial BMCs significantly increased blood flow recovery in ischemic limbs beginning 21 days after surgery and peaking at 27 days (61.8% +/- 15% vs. 41.9% +/- 13.9%, respectively, for BMCs and PBS, P < .05). The BMCs differentiated into small blood vessels, skeletal myofibers, and supporting membranes, and these changes were associated with increased serum levels of vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF-2), transforming growth factor beta (TGFbeta), interleukin 4 (IL-4), and tumor necrosis factor alpha (TNF-alpha).
Adult BMCs injected into ischemic limbs without immunosuppressant therapy differentiated into blood vessels and skeletal myofibers, and this was associated with accelerated blood flow restoration and increased serum levels of VEGF, FGF-2, TGF-beta, IL-4, and TNF-alpha. Skeletal muscle formation may provide benefits beyond angiogenesis to patients with chronic peripheral arterial disease or to patients with low cardiac output states who also suffer from skeletal muscle atrophy.
Vascular and Endovascular Surgery 08/2009; 43(5):433-43. · 0.99 Impact Factor
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ABSTRACT: In autologous saphenous vein grafts, prostacyclin (PGI(1)), a vasoprotective molecule produced by normal endothelial cells, is down-regulated compared with ungrafted saphenous veins and normal carotid arteries. Reduced PGI(2) synthesis may contribute to local platelet deposition, vascular smooth muscle cell (VSMC) accumulation, atherosclerosis, and ultimately failure of venous bypass grafts. We have examined whether gene transfer-mediated overexpression of COX-1 in grafted veins (1) increases PGI(2) and cyclic AMP (cAMP) production, (2) leads to vasodilation and improved local blood flow in the presence of hypercholesterolemia, and (3) reduces neointima formation.
Jugular veins from New Zealand-White rabbits were incubated for 30 min ex vivo with 1 x 10(10) PFU/mL of an adenoviral vector encoding COX-1 (AdCOX-1; n = 10) or empty control (n = 10) and grafted to the carotid arteries. The rabbits were placed on a high-cholesterol diet for 4 w, and blood flow and histomorphometry of the grafts were assessed.
In the AdCOX-1 group, blood flow was significantly increased (16.0 +/- 3.3 versus 12.5 +/- 3.3 mL/min; P < 0.05) compared with controls, and luminal area (8.9 +/- 1.4 versus 5.3 +/- 1.2 mm(2); P < 0.01) and outer circumference were larger. In six identically treated rabbits, graft PGI(2) and cAMP synthesis was increased at 72 h in AdCOX-1 compared with controls.
Our data suggest a 30-min ex vivo exposure of vein grafts to AdCOX-1 increased local synthesis of PGI(2) and cAMP after graft surgery and resulted in better graft lumen and blood flow at 4 w.
Journal of Surgical Research 01/2009; 161(1):162-7. · 2.25 Impact Factor
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ABSTRACT: Cyclooxygenase-1 (COX-1) is the rate-limiting component in the synthesis of prostacyclin (PGI2), an important vasodilator and antithrombotic molecule. In balloon-injured, atherosclerosis-free porcine arteries, COX-1 gene transduction increases PGI2 production, induces durable vasodilation, and reduces thrombus formation. We tested the effectiveness of COX-1 local gene transduction for the prevention of postangioplasty restenosis in atherosclerotic arteries in a hypercholesterolemic rabbit model.
We injured 1 carotid artery in 43 Watanabe heritable hyperlipidemic rabbits and performed local gene transduction using a viral vector containing the COX-1 gene (AdCOX-1, n=22) or no genes (Adnull, n=21). Three days later, AdCOX-1-treated arteries stimulated with arachidonic acid produced 100% more PGI2 (P<0.01), 400% more prostaglandin E2 (PGE2) (P<0.01), 400% more prostaglandin E1 (PGE1) (P<0.01), and 250% more cAMP (P<0.05) than Adnull-treated arteries. Twenty-eight days after treatment, Doppler sonography showed that blood flow velocity was preserved in AdCOX-1-treated arteries (ratio 0.92, injured compared with contralateral uninjured carotid artery) but reduced in Adnull-treated arteries (ratio 0.39), suggesting that AdCOX-1 prevented restenosis after injury. COX-1-transduced arteries also showed 80% greater lumen area 28 days after injury (P<0.01).
The effectiveness of COX-1 in preventing restenosis and preserving normal blood flow 28 days after injury results from increased lumen area caused by durable vasodilation. COX-1 efficacy correlates with an early increase in the production of PGI2, PGE2, PGE1 (known to cause vasodilation), and cAMP. These results demonstrate for the first time that COX-1 gene transduction is an effective treatment for the prevention of postangioplasty restenosis of atherosclerotic arteries under clinically relevant conditions.
Circulation 04/2005; 111(14):1833-40. · 14.74 Impact Factor
