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Biomedical subjects

Yoshiko Ihara

Publications and source records attributed to Yoshiko Ihara.

5 recordsLinked to original sources
PubMed2006

Catheter-based adenovirus-mediated anti-monocyte chemoattractant gene therapy attenuates in-stent neointima formation in cynomolgus monkeys.

We have previously demonstrated great benefit from anti-monocyte chemoattractant protein-1 (MCP-1) gene therapy by "systemic" transfer of an N-terminal deletion mutant of human MCP-1 (called 7ND) gene into skeletal muscle for treatment of restenosis and atherosclerosis. However, recent evidence suggests that "local" gene transfer may be a clinically relevant approach. We therefore tested the hypothesis that catheter-based adenovirus-mediated anti-MCP-1 gene therapy attenuates stent-associated neointima formation. Bare metal stents were implanted in iliac arteries of cynomolgus monkeys fed a high cholesterol diet. Immediately after the stenting procedure, normal saline or recombinant adenoviral vector containing LacZ or the 7ND gene was administered locally into the stenting site through a Remedy channel-delivery catheter. Compared to saline infusion or LacZ gene transfer, 7ND gene transfer markedly reduced inflammatory changes at an early stage and attenuated neointima formation after 4 weeks. This strategy also reduced the increased production of pro-inflammatory and growth-promoting factors such platelet-derived growth factor. No systemic adverse effects of 7ND gene transfer were detected. There were no significant differences in serum cholesterol levels among the three groups. These data suggest that catheter-based adenovirus-mediated anti-MCP-1 gene therapy may be a clinically relevant and feasible strategy for treatment of in-stent restenosis.

Adenoviruses, Human↗
PubMed2006

Stent-based local delivery of nuclear factor-kappaB decoy attenuates in-stent restenosis in hypercholesterolemic rabbits.

BACKGROUND: Nuclear factor-kappaB (NF-kappaB) plays a critical role in the vascular response to injury. However, the role of NF-kappaB in the mechanism of in-stent restenosis remains unclear. We therefore tested the hypothesis that blockade of NF-kappaB by stent-based delivery of a cis-element "decoy" of NF-kappaB reduces in-stent neointimal formation. METHODS AND RESULTS: Stents were coated with a polymer containing or not containing NF-kappaB decoy, which represented a fast-release formulation (<7 days). Bare, polymer-coated, and NF-kappaB decoy-eluting stents were implanted in iliac arteries of hypercholesterolemic rabbits. Increased NF-kappaB activity was noted at early stages after stenting, which was suppressed by stent-based delivery of NF-kappaB decoy. NF-kappaB decoy-eluting stents also reduced monocyte infiltration and monocyte chemoattractant protein-1 expression and suppressed CD14 activation on circulating leukocytes. Importantly, NF-kappaB decoy-eluting stents attenuated neointimal formation on day 28. There was no evidence of an incomplete healing process (persistent inflammation, hemorrhage, fibrin deposition, impaired endothelial regeneration) at the site of NF-kappaB decoy-eluting stents. Transfection of NF-kappaB decoy suppressed proliferation of human coronary artery smooth muscle cells in vitro. No systemic adverse effects of NF-kappaB decoy were detected. CONCLUSIONS: Stent-based local delivery of NF-kappaB decoy reduced in-stent neointimal formation with no evidence of incomplete healing. These data suggest that this strategy may be a practical and promising means for prevention of in-stent restenosis in humans.

Angioplasty, Balloon, Coronary↗
PubMed2006

Angiotensin II type 1 receptor blockade attenuates in-stent restenosis by inhibiting inflammation and progenitor cells.

The precise mechanism by which angiotensin II type 1 receptor blocker reduces in-stent restenosis in clinical trials is unclear. We, therefore, investigated the mechanism of in-stent neointima formation. Male cynomolgus monkeys and rabbits were fed a high-cholesterol diet and were allocated to untreated control and type 1 receptor blocker groups. Five days after grouping, multilink stents were implanted in the iliac artery. The type 1 receptor blocker reduced the development of in-stent neointima formation by approximately 30% in rabbits and monkeys. To investigate potential mechanisms, we examined the expression of renin-angiotensin system markers, all of which increased in monocytes and smooth muscle-like cells in the neointima and media within 7 days. The type 1 receptor blocker attenuated increased oxidative stress, the enhanced expression of markers of the rennin-angiotensin system and monocyte chemoattractant protein-1, and macrophage infiltration. The effects of type 1 receptor blocker on the differentiation of peripheral blood mononuclear cells into vascular progenitor cells were also examined. Treatment with type 1 receptor blocker suppressed the enhanced differentiation to smooth muscle progenitor cells induced by stenting. The type 1 receptor blocker attenuated in-stent neointima formation by inhibiting redox-sensitive inflammatory changes and by reducing recruitment of the progenitor cells. These potential actions of type 1 receptor blocker on inflammation and progenitor cells constitute a novel mechanism of suppression of in-stent restenosis by type 1 receptor blocker.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2004

Bone marrow-derived monocyte chemoattractant protein-1 receptor CCR2 is critical in angiotensin II-induced acceleration of atherosclerosis and aneurysm formation in hypercholesterolemic mice.

UNLABELLED: Angiotensin II (Ang II) is implicated in atherogenesis by activating inflammatory responses in arterial wall cells. Ang II accelerates the atherosclerotic process in hyperlipidemic apoE-/- mice by recruiting and activating monocytes. Monocyte chemoattractant protein-1 (MCP-1) controls monocyte-mediated inflammation through its receptor, CCR2. The roles of leukocyte-derived CCR2 in the Ang II-induced acceleration of the atherosclerotic process, however, are not known. We hypothesized that deficiency of leukocyte-derived CCR2 suppresses Ang II-induced atherosclerosis. METHODS AND RESULTS: A bone marrow transplantation technique (BMT) was used to develop apoE-/- mice with and without deficiency of CCR2 in leukocytes (BMT-apoE-/-CCR2+/+ and BMT-apoE-/-CCR2-/- mice). Compared with BMT-apoE-/-CCR2+/+ mice, Ang II-induced increases in atherosclerosis plaque size and abdominal aortic aneurysm formation were suppressed in BMT-apoE-/-CCR2-/- mice. This suppression was associated with a marked decrease in monocyte-mediated inflammation and inflammatory cytokine expression. CONCLUSIONS: Leukocyte-derived CCR2 is critical in Ang II-induced atherosclerosis and abdominal aneurysm formation. The present data suggest that vascular inflammation mediated by CCR2 in leukocytes is a reasonable target of therapy for treatment of atherosclerosis.

Angiotensin II↗