A slow-releasing form of prostacyclin agonist (ONO1301SR) enhances endogenous secretion of multiple cardiotherapeutic cytokines and improves cardiac function in a rapid-pacing-induced model of canine heart failure

Angiogenesis induction as a key step in cardiac tissue Regeneration: From angiogenic agents to biomaterials

Cardiovascular diseases are the leading cause of death worldwide. After myocardial infarction, the vascular supply of the heart is damaged or blocked, leading to the formation of scar tissue, followed by several cardiac dysfunctions or even death. In this regard, induction of angiogenesis is considered as a vital process for supplying nutrients and oxygen to the cells in cardiac tissue engineering. The current review aims to summarize different approaches of angiogenesis induction for effective cardiac tissue repair. Accordingly, a comprehensive classification of induction of pro-angiogenic signaling pathways through using engineered biomaterials, drugs, angiogenic factors, as well as combinatorial approaches is introduced as a potential platform for cardiac regeneration application. The angiogenic induction for cardiac repair can enhance patient treatment outcomes and generate economic prospects for the biomedical industry. The development and commercialization of angiogenesis methods often involves collaboration between academic institutions, research organizations, and biomedical companies.

Enhanced myocardial blood flow in ischemic cardiomyopathy by a slow-release synthetic prostacyclin agonist combined with coronary artery bypass grafting: The first human study in a Phase I/IIa clinical trial

Background

YS-1402, which is a polymerized form of the synthetic prostacyclin agonist ONO-1301, has been proven in several preclinical studies to induce therapeutic effects for patients with ischemic cardiomyopathy (ICM). In this human study, we assessed the safety, tolerability, and efficacy of YS-1402, combined with coronary artery bypass grafting (CABG), for ICM.

Methods

Twenty-four patients with ICM whose left ventricular ejection fraction was <40% with an indication for CABG were double-blindly assigned to four groups: placebo, 10-mg YS-1402, 30-mg YS-1402, and 100-mg YS-1402. YS-1402 or placebo medications were administered on the surface of the left ventricle at the time of the CABG. Pre- and postoperative cardiac function and myocardial blood flow were assessed for 6 months postoperatively, along with a safety assessment.

Results

No severe adverse events were related to YS-1402. The maximum blood concentration of ONO-1301 was less than that of the no observable adverse effect level. Significantly increased myocardial blood flow (MBF) and cardiac function were observed in the YS-1402 group 26 weeks postoperatively, although no improvement in MBF occurred in the placebo group.

Conclusion

This Phase I/IIa parallel group-controlled, dose-escalation study of YS-1402 combined with CABG for ICM demonstrated the safety, tolerability, and potential efficacy of YS-1402.

New regional drug delivery system by direct epicardial placement of slow-release prostacyclin agonist promise therapeutic angiogenesis in a porcine chronic myocardial infarction

Although prostacyclin is an endogenous factor for the protection and regeneration of damaged tissue, the use of clinically available prostacyclin analogues for treating chronic pathological conditions is limited owing to their short half-lives. A new reagent, ONO-1301SR, which is a unique synthetic prostacyclin agonist polymerized with lactic and glycolic acid, has been demonstrated to constitutively release prostacyclin analogues to adjacent tissues, suggesting its therapeutic potential via slow-release delivery into a specific organ. In this study, we investigated the regenerative effect of direct epicardial delivery of the ONO-1301SR on a heart with a chronic myocardial infarct. An ameroid constrictor was placed on the left anterior descending coronary artery of Göttingen minipigs for 4 weeks to induce ischemic cardiomyopathy; this was followed by direct epicardial placement of ONO-1301SR-immersed gelatinous sheet, or only a gelatinous sheet on the anterolateral surface of the heart. Epicardial placement of ONO-1301SR resulted in significant recovery of global cardiac functions and regional wall motion of the lateral wall. Importantly, after epicardial placement of ONO-1301SR for 4 weeks, the myocardial blood flow significantly increased in the lateral region as assessed by ¹³N-ammonia positron emission tomography; this finding was consistent with significantly increased capillary density in the peri-infarct area with up-regulated angiogenic cytokine expression. Conclusion: Use of the slow-release drug delivery system of prostacyclin agonist yielded regenerative angiogenesis, including increased regional blood perfusion and systolic function in a porcine model of chronic myocardial infarction.

Effect of Co-culturing Fibroblasts in Human Skeletal Muscle Cell Sheet on Angiogenic Cytokine Balance and Angiogenesis

Skeletal muscle comprises a heterogeneous population of myoblasts and fibroblasts. Autologous skeletal muscle myoblasts are transplanted to patients with ischemia to promote cardiac regeneration. In damaged hearts, various cytokines secreted from the skeletal muscle myoblasts promote angiogenesis and consequently the recovery of cardiac functions. However, the effect of skeletal muscle fibroblasts co-cultured with skeletal muscle myoblasts on angiogenic cytokine production and angiogenesis has not been fully understood. To investigate these effects, production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) was measured using the culture medium of monolayers prepared from various cell densities (mono-culture) and proportions (co-culture) of human skeletal muscle myoblasts (HSMMs) and human skeletal muscle fibroblasts (HSMFs). HSMM and HSMF mono-cultures produced VEGF, whereas HSMF mono-culture produced HGF. The VEGF productivity observed in a monolayer comprising low proportion of HSMFs was two-fold greater than that of HSMM and HSMF mono-cultures. The production of VEGF in HSMMs but not in HSMFs was directly proportional to the cell density. VEGF productivity in non-confluent cells with low cell-to-cell contact was higher than that in confluent cells with high cell-to-cell contact. The dynamic migration of cells in a monolayer was examined to analyze the effect of HSMFs on myoblast-to-myoblast contact. The random and rapid migration of HSMFs affected the directional migration of surrounding HSMMs, which disrupted the myoblast alignment. The effect of heterogeneous populations of skeletal muscle cells on angiogenesis was evaluated using human umbilical vein endothelial cells (HUVECs) incubated with fabricated multilayer HSMM sheets comprising various proportions of HSMFs. Co-culturing HSMFs in HSMM sheet at suitable ratio (30 or 40%) enhances endothelial network formation. These findings indicate the role of HSMFs in maintaining cytokine balance and consequently promoting angiogenesis in the skeletal muscle cell sheets. This approach can be used to improve transplantation efficiency of engineered tissues.

Administration of Slow-Release Synthetic Prostacyclin Agonist Promoted Angiogenesis and Skeletal Muscle Regeneration for Limb Ischemia

Gene or cell therapy is currently not fully efficacious for arteriosclerosis obliterans (ASO). In this study, we determined whether YS-1402, a slow-release synthetic prostacyclin agonist, promoted neovascularization and skeletal muscle regeneration in a mouse model of critical limb ischemia (CLI). We ligated the femoral artery and its branches to obtain the CLI mouse model, administered saline (S group) or YS-1402 (YS group) to the thigh adductor 1 week after femoral artery occlusion, and evaluated tissue blood flow after surgery. After treatment, the leg muscle was obtained for histological, gene expression, and protein analyses to assess angiogenesis and skeletal muscle regeneration. Tissue blood flow improved in the YS group compared with that in the S group, and the number of CD31⁺/α-smooth muscle actin (αSMA)⁺ arterioles increased in the YS group. Prostacyclin receptor (IPR), stromal cell-derived factor-1, hepatocyte growth factor, and neural cell adhesion molecule expression levels were higher in the YS than in the S group. Skeletal muscle regeneration was detected based on PAX7- and Ki-67-positive satellite cells in the YS group. Myogenin and MyoD expression was higher in the YS than in the S group. Therefore, YS-1402 promoted functional angiogenesis and skeletal muscle regeneration in the CLI mouse model, suggesting a new therapy for ASO.

Prostacyclin Analogue-Loaded Nanoparticles Attenuate Myocardial Ischemia/Reperfusion Injury in Rats

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Intravenously injected ONO-1301–containing nanoparticles selectively accumulated in the ischemic border area of the myocardium.

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Prominent up-regulation occurred of proangiogenic cytokines such as vascular endothelial growth factor and angiopoietin-1 in the ischemic myocardium, which may have contributed to the preservation of the native vascular and capillary networks, thus preserving regional myocardial blood flow.

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Down-regulation of the proinflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α in the ischemic myocardium might have led to the attenuation of myocyte swelling and the suppression of the endothelial bleb formation, also contributing to the preservation of myocardial blood flow or the reduced infarct size.

Intravenously injected ONO-1301–containing nanoparticles (ONO-1301NPs), unlike an ONO-1301 solution, selectively accumulated in the ischemia/reperfusion (I/R)-injured myocardium of rats and contributed to the prolonged retention of ONO-1301 in the targeted myocardial tissue. In the ischemic area, proangiogenic cytokines were up-regulated and inflammatory cytokines were down-regulated upon ONO-1301NP administration. Consequently, ONO-1301NP–injected rats exhibited a smaller infarct size, better-preserved capillary networks, and a better-preserved myocardial blood flow at 24 h after I/R injury, compared with those in vehicle-injected or ONO-1301 solution–injected rats. ONO-1301NPs attenuate the myocardial I/R injury via proangiogenic and anti-inflammatory effects of the drug.

A sustained-release drug-delivery system of synthetic prostacyclin agonist, ONO-1301SR: a new reagent to enhance cardiac tissue salvage and/or regeneration in the damaged heart

Cardiac failure is a major cause of mortality and morbidity worldwide, since the standard treatment for cardiac failure in the clinical practice is chiefly to focus on removal of insults against the heart or minimisation of additional factors to exacerbate cardiac failure, but not on regeneration of the damaged cardiac tissue. A synthetic prostacyclin agonist, ONO-1301, has been developed as a long-acting drug for acute and chronic pathologies related to regional ischaemia, inflammation and/or interstitial fibrosis by pre-clinical studies. In addition, poly-lactic co-glycolic acid-polymerised form of ONO-1301, ONO-1301SR, was generated to achieve a further sustained release of this drug into the targeted region. This unique reagent has been shown to act on fibroblasts, vascular smooth muscle cells and endothelial cells in the tissue via the prostaglandin IP receptor to exert paracrinal release of multiple protective factors, such as hepatocyte growth factor, vascular endothelial growth factor or stromal cell-derived factor-1, into the adjacent damaged tissue, which is salvaged and/or regenerated as a result. Our laboratory developed a new surgical approach to treat acute and chronic cardiac failure using a variety of animal models, in which ONO-1301SR is directly placed over the cardiac surface to maximise the therapeutic effects and minimise the systemic complications. This review summarises basic and pre-clinical information of ONO-1301 and ONO-1301SR as a new reagent to enhance tissue salvage and/or regeneration, with a particular focus on the therapeutic effects on acute and chronic cardiac failure and underlying mechanisms, to explore a potential in launching the clinical study.

Present and future perspectives on cell sheet-based myocardial regeneration therapy

Heart failure is a life-threatening disorder worldwide and many papers reported about myocardial regeneration through surgical method induced by LVAD, cellular cardiomyoplasty (cell injection), tissue cardiomyoplasty (bioengineered cardiac graft implantation), in situ engineering (scaffold implantation), and LV restrictive devices. Some of these innovated technologies have been introduced to clinical settings. Especially, cell sheet technology has been developed and has already been introduced to clinical situation. As the first step in development of cell sheet, neonatal cardiomyocyte sheets were established and these sheets showed electrical and histological homogeneous heart-like tissue with contractile ability in vitro and worked as functional heart muscle which has electrical communication with recipient myocardium in small animal heart failure model. Next, as a preclinical study, noncontractile myoblast sheets have been established and these sheets have proved to secrete multiple cytokines such as HGF or VEGF in vitro study. Moreover, in vivo studies using large and small animal heart failure model have been done and myoblast sheets could improve diastolic and systolic performance by cytokine paracrine effect such as angiogenesis, antifibrosis, and stem cell migration. Recently evidenced by these preclinical results, clinical trials using autologous myoblast sheets have been started in ICM and DCM patients and some patients showed LV reverse remodelling, improved symptoms, and exercise tolerance. Recent works demonstrated that iPS cell-derived cardiomyocyte sheet were developed and showed electrical and microstructural homogeneity of heart tissue in vitro, leading to the establishment of proof of concept in small and large animal heart failure model.