Rationale Bone marrow (BM)-derived mesenchymal stem cells (MSCs) hold great promise for cardiovascular cell therapy owing to their multipotency and culture-expandability. Objective The aim of the study was to investigate whether MSCs can treat experimental acute myocardial infarction (MI) and diabetic neuropathy. Methods and Results We isolated mononuclear cells from mouse BM and cultured MSCs in a conventional manner. Flow cytometry analyses of these cultured cells at passage four showed expression of typical MSC markers such as CD44 and CD29, but not hematopoietic markers such as c-kit, flk1 and CD34. To determine the therapeutic effects of MSCs, we injected MSCs into the periinfarct area after ligation of the left anterior descending coronary arteries of mice, and as separate experiments injected the same batch of MSCs into hindlimb muscles of mice with diabetic neuropathy. During the follow-up at 4–8 weeks after cell transplantation, growing tumors were observed in 30% of hearts in the MI model, and in 46% of hindlimbs in the diabetic neuropathy model. Histologic examination of the tumors revealed hypercelluarity, pleomorphic nucleoli, cytologic atypia and necrosis, and positive staining for α-smooth muscle actin, indicative of malignant sarcoma with myogenic differentiation. Chromosomal analysis of these MSCs showed multiple chromosomal aberrations including fusion, fragmentation, and ring formation. Conclusions Genetically unmodified MSCs can undergo chromosomal abnormalities even at early passages and form malignant tumors when transplanted in vivo. These results suggest that careful monitoring of chromosomal status is warranted when in vitro expanded MSCs are used for cell therapy such as for MI.

Aims The Korean Acute Heart Failure registry (KorAHF) aims to evaluate the clinical characteristics, management, hospital course, and long‐term outcomes of patients hospitalized for acute heart failure syndrome (AHFS) in Korea. Methods and results This is a prospective observational multicentre cohort study funded by the Korea National Institute of Health. Patients hospitalized for AHFS in 10 tertiary university hospitals across the country have been consecutively enrolled since March 2011. The study is expected to complete the scheduled enrolment of 5000 patients some time in 2014, and follow‐up is planned through 2016. As of April 2012, the interim analysis of 2066 consecutive subjects was performed to understand the baseline characteristics of the population. The mean age was 69 ± 14 years; 55% were male; and 50% were de novo heart failure. The mean left ventricular ejection fraction (LVEF) was 40 ± 18%. Ischaemia was both the leading cause (38%) and the most frequent aggravating factor (26%) of AHFS. ACE inhibitors/ARBs and beta‐blockers were prescribed at discharge in 65% and 51% of the patients, respectively. In‐hospital mortality was 5.2%, and 0.9% of patients received urgent heart transplantation. Low blood pressure and azotaemia were the most important predictors of in‐hospital mortality. The post‐discharge 30‐day and 180‐day all‐cause mortality were 1.2% and 9.2%, respectively. Conclusions Our analysis reveals that the prognosis of AHFS in Korea is poor and that there are specific features, including lower blood pressures at admission and lower rates of heart failure related to hypertension, compared with other registries. Adherence to current guidelines should be improved.

Background and ObjectivesThe burden of heart failure has increased in Korea. This registry aims to evaluate demographics, clinical characteristics, management, and long-term outcomes in patients hospitalized for acute heart failure (AHF).Subjects and MethodsWe prospectively enrolled a total of 5625 consecutive subjects hospitalized for AHF in one of 10 tertiary university hospitals from March 2011 to February 2014. Descriptive statistics were used to determine the baseline characteristics of the study population and to compare them with those from other registries.ResultsThe mean age was 68.5±14.5 years, 53.2% were male, and 52.2% had de novo heart failure. The mean systolic and diastolic blood pressures were 131.2±30.3 mmHg and 78.6±18.8 mmHg at admission, respectively. The left ventricular ejection fraction was ≤40% in 60.5% of patients. Ischemia was the most frequent etiology (37.6%) and aggravating factor (26.3%). Angiotensin converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers, and aldosterone antagonists were prescribed in 68.8%, 52.2%, and 46.6% of the patients at discharge, respectively. Compared with the previous registry performed in Korea a decade ago, extracorporeal membrane oxygenation (ECMO) and heart transplantation have been performed more frequently (ECMO 0.8% vs. 2.8%, heart transplantation 0.3% vs. 1.2%), and in-hospital mortality decreased from 7.6% to 4.8%. However, the total cost of hospital care increased by 40%, and one-year follow-up mortality remained high.ConclusionWhile the quality of acute clinical care and AHF-related outcomes have improved over the last decade, the long-term prognosis of heart failure is still poor in Korea. Therefore, additional research is needed to improve long-term outcomes and implement cost-effective care.

Objectives This study aimed to determine if CD31 is a novel marker of a circulating angio-vasculogenic cell population and to establish their therapeutic effects on experimental ischemia. Background Emerging evidence suggested that therapeutic mechanisms underlying various bone marrow (BM)-derived cells are due to paracrine effects. Furthermore, the vasculogenic potential of these cells is under debate. CD31 is a well known marker for endothelial cells (ECs) but is also expressed in a fraction of peripheral blood (PB) mononuclear cells. Methods CD31+ cells were isolated from human PB by magnetic-activated cell sorting (MACS). The gene expression profile was examined by DNA microarray and real-time RT-PCR (qRT-PCR). Various in vitro endothelial differentiation or vasculogenic assays were conducted. Finally, cells were directly implanted into a mouse hindlimb ischemia (HLI) model to test angiogenic-vasculogenic and therapeutic effects. Results Fluorescent-activated cell sorter (FACS) analysis revealed that PB-CD31+ cells exhibited endothelial and hematopoietic stem/progenitor markers. CD31+ cells had higher levels of expression of pro-angiogenic genes on microarray and qRT-PCR and generated higher numbers of endothelial progenitor cells (EPCs) compared to CD31− cells. CD31+ cells spontaneously formed vascular tube-like structures and exhibited an endothelial cell phenotype in vitro. In a HLI model, CD31+ cell transplantation augmented blood perfusion and prevented limb loss. Both angiogenic cytokines and capillary density were increased, suggesting CD31+ cells augmented neovascularization. Conclusions CD31 is a novel marker that designates circulating angiogenic and vasculogenic cells. These cells are easily isolated from human PB and thus are a novel candidate for treatment of ischemic cardiovascular disease.

Background-Endothelial progenitor cells (EPCs) are known to promote neovascularization in ischemic diseases. Recent evidence suggested that diabetic neuropathy is causally related to impaired angiogenesis and deficient growth factors. Accordingly, we investigated whether diabetic neuropathy could be reversed by local transplantation of EPCs. Methods and Results-We found that motor and sensory nerve conduction velocities, blood flow, and capillary density were reduced in sciatic nerves of streptozotocin-induced diabetic mice but recovered to normal levels after hind-limb injection of bone marrow-derived EPCs. Injected EPCs were preferentially and durably engrafted in the sciatic nerves.A portion of engrafted EPCs were uniquely localized in close proximity to vasa nervorum, and a smaller portion of these EPCs were colocalized with endothelial cells. Multiple angiogenic and neurotrophic factors were significantly increased in the EPC-injected nerves. These dual angiogenic and neurotrophic effects of EPCs were confirmed by higher proliferation of Schwann cells and endothelial cells cultured in EPC-conditioned media. Conclusions-We demonstrate for the first time that bone marrow-derived EPCs could reverse various manifestations of diabetic neuropathy. These therapeutic effects were mediated by direct augmentation of neovascularization in peripheral nerves through long-term and preferential engraftment of EPCs in nerves and particularly vasa nervorum and their paracrine effects. These findings suggest that EPC transplantation could represent an innovative therapeutic option for treating diabetic neuropathy. Key Words: angiogenesis Ⅲ diabetes mellitus Ⅲ progenitor cells Ⅲ diabetic neuropathy P eripheral neuropathy is the most common complication of diabetes mellitus, affecting up to 60% of diabetic patients. 1 Loss of sensation in the feet, the most frequent manifestation of diabetic neuropathy (DN), frequently leads to foot ulcers and may progress into amputation of the limb. 2,3 Despite a continuous increase in the incidence of diabetes mellitus and DN, current treatments have yet to effectively treat DN. Our group reported that experimental DN is characterized by reduced microcirculation in peripheral nerves caused by the destruction of the vasa nervorum and thus administration of angiogenic factors such as vascular endothelial growth factors (VEGFs), sonic hedgehog (SHh), and statin could restore neural function by augmenting angiogenesis. 4 -6 In addition, deficiency of neurotrophic factors is regarded as one of the most plausible mechanisms underlying DN. 7 Alterations of nerve growth factor, ciliary neurotrophic factor, glial-derived neurotrophic factor, and brain-derived neurotrophic factor have been reported. 8 -12 However, in clinical trials, single neurotrophic cytokines turned out to be ineffective for treating DN. 13 Recently, many classic angiogenic factors were shown to possess neurotrophic activities and vice versa. VEGF, [14][15][16]17,18 Received April 29, 2008; accepted November 28, 2008. Cli...

Rationale: Bone marrow (BM) cells play an important role in physiological and therapeutic neovascularization.However, it remains unclear whether any specific uncultured BM cell populations have higher angiogenic and vasculogenic activities. Moreover, there has been controversy regarding the vasculogenic ability of BM cells.Objective: Preliminary flow cytometric analysis showed that CD31, traditionally a marker for endothelial cells, is expressed in certain nonendothelial BM mononuclear cells in both human and mouse. Based on the conserved CD31 expression in the axis of hematopoietic stem/progenitor cells (HSC/HPCs) to endothelial cells, we further sought to determine the comprehensive vasculogenic and angiogenic characteristics of human and mouse BM-derived CD31 ؉ cells. Methods and Results: Flow cytometric analysis demonstrated that all CD31؉ cells derived from BM were CD45 ؉ and expressed markers for both HSC/HPCs and endothelial cells. Comprehensive gene expression analyses revealed that BM-CD31؉ cells expressed higher levels of angiogenic genes than CD31 ؊ cells. Endothelial progenitor cells, as well as HSC/HPCs, were almost exclusively confined to the CD31 ؉ cell fraction, and culture of CD31؉ cells under defined conditions gave rise to endothelial cells. Finally, injection of CD31 ؉ cells into ischemic hindlimb repaired ischemia, increased expression of angiogenic and chemoattractive factors, and, in part, directly contributed to vasculogenesis, as demonstrated by both 3D confocal microscopy and flow cytometry. Conclusions: These data indicate that BM-CD31؉ cells represent highly angiogenic and vasculogenic cells and can be a novel and highly promising source of cells for cell therapy to treat ischemic cardiovascular diseases. (Circ Res. 2010;107:602-614.) Key Words: bone marrow Ⅲ CD31 (PECAM-1) angiogenesis Ⅲ vasculogenesis Ⅲ peripheral vascular disease F ormation of new blood vessels (neovascularization) consists of 2 processes, vasculogenesis and angiogenesis. Vasculogenesis refers to the de novo development of blood vessels from endothelial progenitor cells (EPCs) or angioblasts which differentiate into endothelial cells (ECs). In contrast, angiogenesis is the formation of new vasculature from preexisting blood vessels through proliferation, migration, and remodeling of differentiated ECs. The identification of circulating EPCs in adult vertebrates suggested a role for BM cells in postnatal vasculogenesis, 1-3 and led to trials of BM cells for therapy for ischemic cardiovascular diseases.However, conflicting results from recent clinical trials 4,5 suggests a need for the discovery of new cell types 6 and more thorough investigation of the therapeutic mechanisms.Two of the most important questions in current EPC biology are whether the reported cultured EPCs or similar BM cells have true vasculogenic potential and whether a specific marker can prospectively identify true EPCs or vasculogenic cells. The endothelial differentiation or vasculogenic potential of early EPCs has been questioned. 7,3,8 -11 ...

Background-Cell-based therapies to augment endothelial cells (ECs) hold great therapeutic promise. Here, we report a novel approach to generate functional ECs directly from adult fibroblasts. Methods and Results-Eleven candidate genes that are key regulators of endothelial development were selected. Green fluorescent protein (GFP)-negative skin fibroblasts were prepared from Tie2-GFP mice and infected with lentiviruses allowing simultaneous overexpression of all 11 factors. Tie2-GFP + cells (0.9%), representing Tie2 gene activation, were detected by flow cytometry. Serial stepwise screening revealed 5 key factors (Foxo1, Er71, Klf2, Tal1, and Lmo2) that were required for efficient reprogramming of skin fibroblasts into Tie2-GFP + cells (4%). This reprogramming strategy did not involve pluripotency induction because neither Oct4 nor Nanog was expressed after 5 key factor transduction. Tie2-GFP + cells were isolated using fluorescence-activated cell sorting and designated as induced ECs (iECs). iECs exhibited endothelium-like cobblestone morphology and expressed EC molecular markers. iECs possessed endothelial functions such as Bandeiraea simplicifolia-1 lectin binding, acetylated low-density lipoprotein uptake, capillary formation on Matrigel, and nitric oxide production. The epigenetic profile of iECs was similar to that of authentic ECs because the promoters of VE-cadherin and Tie2 genes were demethylated. mRNA profiling showed clustering of iECs with authentic ECs and highly enriched endothelial genes in iECs. In a murine model of hind-limb ischemia, iEC implantation increased capillary density and enhanced limb perfusion, demonstrating the in vivo viability and functionality of iECs. Conclusions-We

Our results indicate that resistin aggravates atherosclerosis by stimulating monocytes, endothelial cells, and vascular smooth muscle cells to induce vascular inflammation. These findings provide the first insight on the causal relationship between resistin and atherosclerosis.