Long-Term Results of Intracardiac Mesenchymal Stem Cell Transplantation in Patients With Cardiomyopathy.

BACKGROUND: Mesenchymal stem cells (MSCs), which have the potential to differentiate into cardiomyocytes or vascular endothelial cells, have been used clinically as therapy for cardiomyopathy. In this study, we aimed to evaluate the long-term follow-up results.Methods and Results:We studied 8 patients with symptomatic heart failure (HF) on guideline-directed therapy (ischemic cardiomyopathy, n=3; nonischemic cardiomyopathy, n=5) who underwent intracardiac MSC transplantation using a catheter-based injection method between May 2004 and April 2006. Major adverse events and hospitalizations were investigated up to 10 years afterward. Compared with baseline, there were no significant differences in B-type natriuretic peptide (BNP) (from 211 to 173 pg/mL), left ventricular ejection fraction (LVEF) (from 24% to 26%), and peak oxygen uptake (from 16.5 to 19.2 mL/min/kg) at 2 months. During the follow-up period, no patients experienced serious adverse events such as arrhythmias. Three patients died of pneumonia in the 1st year, liver cancer in the 6th year, and HF in the 7th year. Of the remaining 5 patients, 3 patients were hospitalized for exacerbated HF, 1 of whom required heart transplantation in the 2nd year; 2 patients survived for 10 years without worsening HF. CONCLUSIONS: The results of this exploratory study of intracardiac MSCs administration suggest further research regarding the feasibility and efficacy is warranted.

The effect of serum on the proliferation of bone marrow-derived mesenchymal stem cells from aged donors and donors with or without chronic heart failure.

Many clinical studies of regenerative medicine using bone marrow-derived mesenchymal stem cells (MSCs) have been conducted globally. We initiated clinical studies using MSCs in 2001 and have now treated over 100 cases with patients aged 0-92 years. In a few cases involving patients with chronic heart failure (CHF), we observed that MSCs proliferated poorly. This contrasts with cell therapy studies wherein MSCs of patients with CHF were used for treatment. The effects of serum on the proliferation of MSCs from donors with normal heart function and with CHF have not been reported. Moreover, whether cell therapy is effective for elderly patients remains uncertain. Therefore, characterization of MSCs from aged donors and/or donors with CHF is urgently required. We retrospectively analysed the population doubling times (PDTs) of MSCs between the first and second passages. Although we had data for many samples of well-expanded MSCs from aged donors, a positive correlation was observed between donor age and PDT. A trend towards reduced variance in PDTs was observed in MSCs supplemented with fetal bovine serum (FBS) compared with those supplemented with autologous serum. When autologous serum was used, the average PDT of MSCs from donors with CHF was significantly longer than that of MSCs from donors without CHF. In contrast, when FBS was used, similar PDTs were observed in MSCs from donors with and without CHF. Thus, FBS promotes MSC expansion even from donors with CHF and MSC-based regenerative medicine might be feasible even for elderly patients. Copyright © 2016 John Wiley & Sons, Ltd.

Adipose-derived stem cell sheet transplantation therapy in a porcine model of chronic heart failure.

Adipose-derived stem cells (ASCs) are a promising resource for cell transplantation therapy for damaged heart tissue. Cell death in the graft early after transplantation represents the main cause of unsatisfactory therapeutic efficacy, but tissue-engineered cell sheets grown in temperature-responsive cell culture dishes may enable improved engraftment of transplanted cells. We investigated the therapeutic potential of this method in chronic myocardial ischemia in swine. We created a porcine model of chronic heart failure by implanting an ameroid constrictor around the main trunk of the left anterior descending artery, just distal to the circumflex branch. Simultaneously, ASCs were obtained from a piece of subcutaneous adipose tissue and expanded to form ASC sheets using temperature-responsive dishes. Four weeks after ameroid constrictor placement, triple-layered ASC sheets were transplanted onto the area of the ischemic myocardium (sheet group, n = 7). Controls (n = 7) received no sheet. Just before and 4 weeks after transplantation, left ventriculography (LVG) and coronary angiography (CAG) were performed. LVG revealed a significant improvement in the left ventricular ejection fraction of the sheet group compared with controls (47.6 ± 2.9% vs 41.4 ± 2.8%, P < 0.05). Furthermore, development of collateral vessels was only detected in the sheet group with right CAG. Histologic analysis demonstrated that engrafted ASC sheets grew to form a thickened layer that included newly formed vessels. ASC sheet transplantation therapy is an intriguing therapeutic method for ischemic heart failure.

Ghrelin treatment of cachectic patients with chronic obstructive pulmonary disease: a multicenter, randomized, double-blind, placebo-controlled trial.

BACKGROUND: Pulmonary cachexia is common in advanced chronic obstructive pulmonary disease (COPD), culminating in exercise intolerance and a poor prognosis. Ghrelin is a novel growth hormone (GH)-releasing peptide with GH-independent effects. The efficacy and safety of adding ghrelin to pulmonary rehabilitation (PR) in cachectic COPD patients were investigated. METHODOLOGY/PRINCIPAL FINDINGS: In a multicenter, randomized, double-blind, placebo-controlled trial, 33 cachectic COPD patients were randomly assigned PR with intravenous ghrelin (2 µg/kg) or placebo twice daily for 3 weeks in hospital. The primary outcomes were changes in 6-min walk distance (6-MWD) and the St. George Respiratory Questionnaire (SGRQ) score. Secondary outcomes included changes in the Medical Research Council (MRC) scale, and respiratory muscle strength. At pre-treatment, serum GH levels were increased from baseline levels by a single dose of ghrelin (mean change, +46.5 ng/ml; between-group p<0.0001), the effect of which continued during the 3-week treatment. In the ghrelin group, the mean change from pre-treatment in 6-MWD was improved at Week 3 (+40 m, within-group p = 0.033) and was maintained at Week 7 (+47 m, within-group p = 0.017), although the difference between ghrelin and placebo was not significant. At Week 7, the mean changes in SGRQ symptoms (between-group p = 0.026), in MRC (between-group p = 0.030), and in maximal expiratory pressure (MEP; between-group p = 0.015) were better in the ghrelin group than in the placebo group. Additionally, repeated-measures analysis of variance (ANOVA) indicated significant time course effects of ghrelin versus placebo in SGRQ symptoms (p = 0.049) and MEP (p = 0.021). Ghrelin treatment was well tolerated. CONCLUSIONS/SIGNIFICANCE: In cachectic COPD patients, with the safety profile, ghrelin administration provided improvements in symptoms and respiratory strength, despite the lack of a significant between-group difference in 6-MWD. TRIAL REGISTRATION: UMIN Clinical Trial Registry C000000061.

Gene and protein expression analysis of mesenchymal stem cells derived from rat adipose tissue and bone marrow.

BACKGROUND: Mesenchymal stem cells (MSC) are multipotent and reside in bone marrow (BM), adipose tissue and many other tissues. However, the molecular foundations underlying the differences in proliferation, differentiation potential and paracrine effects between adipose tissue-derived MSC (ASC) and BM-derived MSC (BM-MSC) are not well-known. Therefore, we investigated differences in the gene and secretory protein expressions of the 2 types of MSC. METHODS AND RESULTS: ASC and BM-MSC were obtained from subcutaneous adipose tissue and BM of adult Lewis rats. ASC proliferated as rapidly as BM-MSC, and had expanded 200-fold in approximately 2 weeks. On microarray analysis of 31,099 genes, 571 (1.8%) were more highly (>3-fold) expressed in ASC, and a number of these genes were associated with mitosis and immune response. On the other hand, 571 genes (1.8%) were more highly expressed in BM-MSC, and some of these genes were associated with organ development and morphogenesis. In secretory protein analysis, ASC secreted significantly larger amounts of growth factor and inflammatory cytokines, such as vascular endothelial growth factor, hepatocyte growth factor and interleukin 6, whereas BM-MSC secreted significantly larger amounts of stromal-derived factor-1α. CONCLUSIONS: There are significant differences between ASC and BM-MSC in the cytokine secretome, which may provide clues to the molecule mechanisms associated with tissue regeneration and alternative cell sources.

Adrenomedullin reduces expression of adhesion molecules on lymphatic endothelial cells.

Adrenomedullin (AM) is a novel vasoactive peptide which regulates vascular tone and vascular endothelial cell growth. We recently reported that lymphatic endothelial cells (LECs) are also an attractive target of AM and concluded that AM is a potent mediator of lympangiogenesis. In the present study, we conducted a genome-wide analysis of genes that are regulated by AM in LECs. AM profoundly suppressed gene expression of cell adhesion receptors and inflammatory factors in LECs, such as intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), endothelial adhesion molecule-1 (E-selectin), interleukin-8, and chemokines, QRT-PCR and flow cytometry analysis showed that AM dose-dependently suppressed the TNF-a-induced mRNA and protein expression of ICAM-1 and VCAM-l. Treatment of LECs with a cell permeable cyclic adenosine monophosphate (cAMP) analog, 8-Br-cAMP, mimicked the suppressive effect of AM on the expression of adhesion molecules. Moreover, both AM and 8-Br-cAMP suppressed TNF-α-induced NF-κB activation in LECs, indicating that AM reduces expression of adhesion molecules in LECs via a cAMP/NF-kB dependent pathway. These results suggest that AM may have an important role in the regulation of the expression of adhesion molecules in lymphatic endothelium, which is critical in the control of immune and inflammatory responses.

The first clinical pilot study of intravenous adrenomedullin administration in patients with acute myocardial infarction.

Adrenomedullin (AM) is a 52-amino-acid vasodilator peptide that was originally isolated from human pheochromocytoma. In the previous experimental study with rat ischemia/reperfusion model, AM reduced infarct size and inhibited myocyte apoptosis. AM also suppressed the production of oxygen-free radicals. The present study was designed to evaluate the feasibility of intravenous administration of AM in patients with acute myocardial infarction. We studied 10 patients with first acute myocardial infarction [male to female ratio: 9 to 1, age: 65 ± 9 (mean ± SD) years, peak creatine phosphokinase level: 4215 ± 1933 (SD) U/L], who were hospitalized within 12 hours of symptom onset. Proceeding reperfusion therapy, AM infusion was initiated and continued at concentration of 0.0125-0.025 µg·kg·min for 12 hours. Follow-up coronary angiography and left ventriculography were performed at 3 months. Cardiac magnetic resonance was examined at 1 month and 3 months after AM therapy. During infusion of AM, hemodynamics kept stable except 2 patients. Wall motion index in the infarct area at 3 months was significantly improved compared with that at baseline, and infarct size evaluated by cardiac magnetic resonance was significantly decreased at 3 months. In conclusion, intravenous administration of AM, which possesses a variety of potential cardiovascular protective actions, can be adjunctive to percutaneous coronary intervention.

Impact of anti-apoptotic and anti-oxidative effects of bone marrow mesenchymal stem cells with transient overexpression of heme oxygenase-1 on myocardial ischemia.

Although mesenchymal stem cells (MSCs) have therapeutic potential for tissue injury, intolerance and poor cell viability limit their reparative capability. Therefore, we examined the impact of bone marrow-derived MSCs, in which heme oxygenase-1 (HO-1) was transiently overexpressed, on the repair of an ischemic myocardial injury. When MSCs and HO-1-overexpressed MSCs (MSC(HO-1)) were exposed to serum deprivation/hypoxia or H(2)O(2)-induced oxidative stress, MSC(HO-1) exhibited increased resistance to cell apoptosis compared with MSCs (17 +/- 1 vs. 30 +/- 2%, P < 0.05) and were markedly resistant to cell death (2 +/- 1 vs. 32 +/- 2%, P < 0.05). Under these conditions, vascular endothelial growth factor (VEGF) production was 2.1-fold greater in MSC(HO-1) than in MSCs. Pretreatment of MSCs and MSC(HO-1) with phosphatidylinositol 3-kinase (PI 3-kinase)/protein kinase B (Akt) pathway inhibitors such as LY-294002 (50 muM) or wortmannin (100 nM) significantly decreased VEGF production. In a rat infarction model with MSCs or MSC(HO-1) (5 x 10(6) +/- 0.1 x 10(6) cells/rat) transplantation, the number of TdT-mediated dUTP nick end-labeling-positive cells was significantly lower in the MSC(HO-1) group than in the MSC group (12.1 +/- 1.0 cells/field vs. 26.5 +/- 2.6, P < 0.05) on the 4th day after cell transplantation. On the 28th day, increased capillary density associated with decreased infarction size was observed in the MSC(HO-1) group (1,415 +/- 47/mm(2) with 21.6 +/- 2.3%) compared with those in the MSCs group (1,215 +/- 43/mm(2) with 28.2 +/- 2.3%, P < 0.05), although infarction size relative to area at risk was not different in each group at 24 h after transplantation. These results demonstrate that MSC(HO-1) exhibit markedly enhanced anti-apoptotic and anti-oxidative capabilities compared with MSCs, thus contributing to improved repair of ischemic myocardial injury through cell survival and VEGF production associated with the PI 3-kinase/Akt pathway.

Nonviral delivery of siRNA into mesenchymal stem cells by a combination of ultrasound and microbubbles.

Cell therapy is a promising therapeutic strategy for regenerative medicine. However, its current efficacy is insufficient, because of the short lifetime and low engraftment of transplanted cells. Transplantation of genetically modified stem cells has been reported to improve the efficacy of cell therapy. The aim of this study was to elucidate the feasibility of a combination of ultrasound and microbubbles (US-MB) for delivery of small interfering RNA (siRNA) into mesenchymal stem cells (MSC). Although cell damage was observed after US-MB treatment, the transfection efficiency determined using fluorescent-labeled siRNA was significantly increased after US-MB. Furthermore, the intracellular delivery of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) siRNA by US-MB resulted in significant knockdown of PTEN mRNA expression and activation of Akt, a mediator of a survival signaling pathway. Our results indicate that US-MB could serve as a nonviral delivery method of siRNA into MSC. The transplantation of genetically modified MSC by US-MB could be a useful strategy for regenerative medicine in the future.

Adrenomedullin induces lymphangiogenesis and ameliorates secondary lymphoedema.

AIMS: Adrenomedullin (AM) is a multifunctional peptide hormone that plays a significant role in vasodilation and angiogenesis. Lymphoedema is a common but refractory disorder that is difficult to be treated with conventional therapy. We therefore investigated whether AM promotes lymphangiogenesis and improves lymphoedema. METHODS AND RESULTS: The effects of AM on lymphatic endothelial cells (LEC) were investigated. AM promoted proliferation, migration, and network formation of cultured human lymphatic microvascular endothelial cells (HLMVEC). AM increased intracellular cyclic adenosine monophosphate (cAMP) level in HLMVEC. The cell proliferation induced by AM was inhibited by a cAMP antagonist and mitogen-activated protein kinase kinase (MEK) inhibitors. Phosphorylated extracellular signal-regulated kinase (ERK) in HLMVEC was increased by AM. Continuous administration of AM (0.05 microg/kg/min) to BALB/c mice with tail lymphoedema resulted in a decrease in lymphoedema thickness. AM treatment increased the number of lymphatic vessels and blood vessels in the injury site. CONCLUSION: AM promoted LEC proliferation at least in part through the cAMP/MEK/ERK pathway, and infusion of AM induced lymphangiogenesis and improved lymphoedema in mice.

Allogeneic injection of fetal membrane-derived mesenchymal stem cells induces therapeutic angiogenesis in a rat model of hind limb ischemia.

Bone marrow-derived mesenchymal stem cells (BM-MSC) have been demonstrated to be an attractive therapeutic cell source for tissue regeneration and repair. However, it remains unknown whether or not allogeneic transplantation of mesenchymal stem cells (MSC) derived from fetal membranes (FM), which are generally discarded as medical waste after delivery, has therapeutic potential. FM-MSC were obtained from Lewis rats and had surface antigen expression and multipotent potential partly similar to those of BM-MSC. Compared with BM-MSC, FM-MSC secreted a comparable amount of hepatocyte growth factor despite a small amount of vascular endothelial growth factor. FM-MSC and BM-MSC both expressed major histocompatibility complex (MHC) class I but not MHC class II antigens and did not elicit allogeneic lymphocyte proliferation in mixed lymphocyte culture. FM-MSC or BM-MSC obtained from Lewis rats were injected into a MHC-mismatched August-Copenhagen-Irish rat model of hind limb ischemia. Three weeks after injection, blood perfusion and capillary density were significantly higher in the FM-MSC and BM-MSC groups than in the phosphate-buffered saline group, and allogeneic FM-MSC and BM-MSC were still observed. In nonischemic hind limb tissues, allogeneic FM-MSC and BM-MSC injection were associated with a comparatively small amount of T lymphocyte infiltration, compared with the injection of allogeneic splenic lymphocytes. In conclusion, allogeneic FM-MSC injection did not elicit a lymphocyte proliferative response and provided significant improvement in a rat model of hind limb ischemia, comparable to the response to BM-MSC. Thus, allogeneic injection of FM-MSC may be a new therapeutic strategy for the treatment of severe peripheral vascular disease. Disclosure of potential conflicts of interest is found at the end of this article.

Stem cell implantation for myocardial disorders.

Cell therapy is currently attracting growing interest as a potential new means of improving the prognosis of patients with heart failure. For practical reasons, autologous skeletal myoblasts have been the first to be tested in clinical trials, but recently cardiovascular researchers has explored many other cell types, including bone marrow cells, endothelial progenitor cells, mesenchymal stem cells, embryonic stem cells, and resident cardiac stem cells. While recent experimental studies and early-phase clinical trials seem to support the concept that cell therapy may enhance cardiac repair, many challenges remain before achieving this goal. Further studies should focus on finding the optimal donor cells for transplantation, the mechanism by which engrafted cells improve cardiac function, controlling the survival and proliferation of transplanted cells, and the development of more efficient cell delivery techniques.

Activation of cardiac progenitor cells through paracrine effects of mesenchymal stem cells.

Mesenchymal stem cells (MSC) transplantation has been proved to be promising strategy to treat the failing heart. The effect of MSC transplantation is thought to be mediated mainly in a paracrine manner. Recent reports have suggested that cardiac progenitor cells (CPC) reside in the heart. In this study, we investigated whether MSC had paracrine effects on CPC in vitro. CPC were isolated from the neonatal rat heart using an explant method. MSC were isolated from the adult rat bone marrow. MSC-derived conditioned medium promoted proliferation of CPC and inhibited apoptosis of CPC induced by hypoxia and serum starvation. Chemotaxis chamber assay demonstrated that MSC-derived conditioned medium enhanced migration of CPC. Furthermore, MSC-derived conditioned medium upregulated expression of cardiomyocyte-related genes in CPC such as beta-myosin heavy chain (beta-MHC) and atrial natriuretic peptide (ANP). In conclusion, MSC-derived conditioned medium had protective effects on CPC and enhanced their migration and differentiation.

Contrast sonography enables noninvasive and quantitative assessment of neovascularization after stem cell transplantation.

Stem cell transplantation is one of the attractive therapeutic strategies for the treatment of hindlimb ischemia. However, few studies have quantitatively assessed perfusion noninvasively in deep tissues after cell transplantation. In this study, we examined the feasibility of contrast sonography for the assessment of perfusion after bone marrow-derived mesenchymal stem cell (MSC) transplantation by using a rat unilateral hindlimb ischemia model. The quantitative parameters derived from contrast sonography were compared with the colored microspheres-derived blood flow and the capillary density. Nine rats were assigned each to a control (saline injection) or a treated (MSC transplantation) group. Video intensity vs. pulsing interval plots were acquired with ultraharmonic imaging of SONOS5500 during IV infusion of Levovist. The left-to-right ratio of hindlimb blood volume (A-ratio), microbubble velocity (beta-ratio) and hindlimb blood flow (Abeta-ratio) were calculated. The MS-ratio, the ratio of the left to the right hindlimb blood flow determined using colored microspheres, was also calculated. Although A-ratio did not change, beta- and Abeta-ratio in the treated group were significantly higher than those in the control group. In addition, MS-ratio and capillary density in the treated group were significantly higher than those in the control group. Compared with A- and Abeta-ratio, beta-ratio had the highest correlation with MS-ratio and capillary density (vs. MS-ratio: r = 0.66, p < 0.01; vs. capillary density: r = 0.52, p < 0.05). The results of our study imply that the contrast sonography-derived beta-ratio is a useful parameter that reflects the perfusion after cell transplantation in ischemic hindlimb.

Human mesenchymal stem cells as a stable source of VEGF-producing cells.

Vascular endothelial growth factor (VEGF) is a positive regulator and plays a crucial role in angiogenesis. We demonstrate that VEGF was highly expressed in cultures of human bone marrow-derived mesenchymal stem cells (hMSCs) and the high expression level was maintained during prolonged culture periods (checked up to passage 10). We also confirmed that in vivo hMSCs engrafted into immunodeficient mice could survive and secreted human VEGF. These findings suggest that implantation of hMSCs is a practical means as a source of VEGF production and might be effective in neoangiogenesis.

[Regenerative medicine for heart failure].

Heart failure is one of the most important cardiovascular health problems throughout the world and has high mortality, and there is a need to develop more effective therapeutic strategies to replace such specialized treatment as mechanical circulatory support and cardiac transplantation. Mesenchymal stem cells (MSC) are multipotent plastic-adherent cells obtained from bone marrow, adipose tissue, and other tissues and can be easily expanded in culture. MSC exert their role in cardiac regeneration not only by differentiating into specific cell types such as cardiomyocytes and vascular endothelial cells but also through paracrine effects via secretion of angiogenic and antiapoptotic factors. On the basis of information obtained from basic and translational research, several clinical trials have recently been started to evaluate the safety and efficacy of autologous MSC for heart failure.

Tissue regeneration as next-generation therapy for COPD--potential applications.

COPD is a major cause of chronic morbidity and mortality worldwide, and there is a need to develop more effective therapeutic strategies to replace specialized treatment such as lung transplantation. Recent studies suggest that recognition of apoptotic lung epithelial or endothelial cells may result in growth factors to stimulate cell replacement, and defects in these processes may contribute to the pathogenesis of COPD. Furthermore, recent animal and human studies have revealed that tissue-specific stem cells and bone marrow-derived cells contribute to lung tissue regeneration and protection, and thus administration of exogenous stem/progenitor cells or humoral factors responsible for activation of endogenous stem/progenitor cells may be a potent next-generation therapy for COPD.

Transplantation of mesenchymal stem cells improves atrioventricular conduction in a rat model of complete atrioventricular block.

Mesenchymal stem cells (MSCs) are multipotent cells that differentiate into a variety of lineages including myocytes and vascular endothelial cells. However, little information is available regarding the therapeutic potential of MSCs in patients with atrioventricular block (AVB). We investigated whether local implantation of MSCs improves AV conduction in a rat model of complete AVB. Complete AVB was achieved by injection of ethanol into the AV nodal region of Lewis rats. Five days after ethanol injection, 2 x 10(6) of MSCs (MSC group) or vehicle (Control group) were injected into the AV nodal region. Animals were monitored by electrocardiograms for 14 days, and physiological and histological examinations were performed. The 1:1 AV conduction was recovered in 5 of 15 rats (33%) in the MSC group during the followup period, whereas no improvement was observed in the control group. MSC transplantation significantly decreased collagen deposition in the AV node, which was associated with a marked decrease in transforming growth factor-beta1 expression. In vitro experiments demonstrated that MSCs secreted a large amount of antifibrotic factors such as hepatocyte growth factor and interleukin-10, and MSC conditioned medium inhibited the growth of adult cardiac fibroblasts. In addition, local injection of MSC conditioned medium recovered AV conduction in 2 of 15 rats (13%). MSC transplantation improved AV conduction in a rat model of complete AVB, at least in part through antifibrotic paracrine effects.

Single injection of a sustained-release prostacyclin analog improves pulmonary hypertension in rats.

RATIONALE: Although prostacyclin is recognized as a therapeutic breakthrough for pulmonary hypertension, it needs continuous infusion because of its short action. Therefore, we developed a new drug delivery system for prostacyclin. We prepared ONO-1301MS, a novel sustained-release prostacyclin analog polymerized with poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres. OBJECTIVES: We examined whether ONO-1301MS attenuates monocrotaline (MCT)-induced pulmonary hypertension in rats, and attempted to elucidate the underlying mechanisms responsible for the beneficial effects of ONO-1301MS. METHODS: After MCT injection, rats were randomized to receive a single subcutaneous injection of 100 mg/kg ONO-1301MS or vehicle. MEASUREMENTS AND MAIN RESULTS: We prepared ONO-1301MS, which was polymerized with PLGA to release ONO-1301 for 3 weeks. A single administration of ONO-1301MS achieved sustained elevation of its circulating level and plasma cyclic adenosine 3',5'-monophosphate level for 3 weeks, and attenuated an increase in a metabolite of thromboxane A(2) level. Rats had developed pulmonary hypertension 3 weeks after MCT injection; however, treatment with ONO-1301MS significantly attenuated the increases in right ventricular systolic pressure and right ventricular weight to body weight ratio. ONO-1301MS significantly inhibited hypertrophy of pulmonary arteries. Phosphorylation of extracellular signal-regulated protein kinase (ERK) in the lung was significantly increased in the control group, whereas this increase was markedly attenuated by treatment. CONCLUSIONS: We developed a new drug delivery system for prostacyclin using PLGA and ONO-1301. A single injection of ONO-1301MS resulted in sustained activity for 3 weeks, and attenuated pulmonary hypertension, partly through its antiproliferative effect on vascular smooth muscle cells via inhibition of ERK phosphorylation.

Mesenchymal stem cells for the treatment of heart failure.

Heart failure is one of the most important cardiovascular health problems throughout the world and has high mortality, and there is a need to develop more effective therapeutic strategies to replace such specialized treatment as mechanical circulatory support and cardiac transplantation. Mesenchymal stem cells (MSC) are multipotent plastic-adherent cells obtained from bone marrow, adipose tissue, and other tissues and can be easily expanded in culture. The ability of MSC to differentiate into a variety of cells, including cardiomyocytes and vascular endothelial cells, make them an attractive therapeutic tool for heart failure. Recent in vitro and in vivo studies have revealed the underlying mechanisms of MSC in cardiac repair. MSC exert their role in cardiac regeneration not only by differentiating into specific cell types such as cardiomyocytes and vascular endothelial cells but also through paracrine effects via secretion of a variety of angiogenic, antiapoptotic, and mitogenic factors. Endogenous MSC as well as exogenously administered MSC have also been suggested to migrate and participate in cardiac repair. On the basis of information obtained from basic and translational research, several clinical trials have recently been started to evaluate the safety and efficacy of autologous MSC for heart failure.