• Biomolecules & Therapeutics
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• 제24권4호
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• pp.363-370
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• 2016

Cardiovascular disease is the most common cause of death in diabetic patients. Hyperglycemia is the primary characteristic of diabetes and is associated with many complications. The role of hyperglycemia in the dysfunction of human cardiac progenitor cells that can regenerate damaged cardiac tissue has been investigated, but the exact mechanism underlying this association is not clear. Thus, we examined whether hyperglycemia could regulate mitochondrial dynamics and lead to cardiac progenitor cell dysfunction, and whether blocking glucose uptake could rescue this dysfunction. High glucose in cardiac progenitor cells results in reduced cell viability and decreased expression of cell cycle-related molecules, including CDK2 and cyclin E. A tube formation assay revealed that hyperglycemia led to a significant decrease in the tube-forming ability of cardiac progenitor cells. Fluorescent labeling of cardiac progenitor cell mitochondria revealed that hyperglycemia alters mitochondrial dynamics and increases expression of fission-related proteins, including Fis1 and Drp1. Moreover, we showed that specific blockage of GLUT1 improved cell viability, tube formation, and regulation of mitochondrial dynamics in cardiac progenitor cells. To our knowledge, this study is the first to demonstrate that high glucose leads to cardiac progenitor cell dysfunction through an increase in mitochondrial fission, and that a GLUT1 blocker can rescue cardiac progenitor cell dysfunction and downregulation of mitochondrial fission. Combined therapy with cardiac progenitor cells and a GLUT1 blocker may provide a novel strategy for cardiac progenitor cell therapy in cardiovascular disease patients with diabetes.

• Biomolecules & Therapeutics
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• 제21권3호
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• pp.196-203
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• 2013

Recent accumulating studies have reported that hypoxic preconditioning during ex vivo expansion enhanced the self-renewal or differentiation of various stem cells and provide an important strategy for the adequate modulation of oxygen in culture conditions, which might increase the functional bioactivity of these cells for cardiac regeneration. In this study, we proposed a novel priming protocol to increase the functional bioactivity of cardiac progenitor cells (CPCs) for the treatment of cardiac regeneration. Firstly, patient-derived c-$kit^+$ CPCs isolated from the atrium of human hearts by enzymatic digestion and secondly, pivotal target molecules identified their differentiation into specific cell lineages. We observed that hCPCs, in response to hypoxia, strongly activated ERK phosphorylation in ex vivo culture conditioning. Interestingly, pre-treatment with an ERK inhibitor, U0126, significantly enhanced cellular proliferation and tubular formation capacities of CPCs. Furthermore, we observed that hCPCs efficiently maintained the expression of the c-kit, a typical stem cell marker of CPCs, under both hypoxic conditioning and ERK inhibition. We also show that hCPCs, after preconditioning of both hypoxic and ERK inhibition, are capable of differentiating into smooth muscle cells (SMCs) and cardiomyocytes (CMs), but not endothelial cells (ECs), as demonstrated by the strong expression of ${\alpha}$-SMA, Nkx2.5, and cTnT, respectively. From our results, we conclude that the functional bioactivity of patient-derived hCPCs and their ability to differentiate into SMCs and CMs can be efficiently increased under specifically defined culture conditions such as short-term hypoxic preconditioning and ERK inhibition.

• 대한핵의학회지
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• 제38권2호
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• pp.175-179
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• 2004

Molecular nuclear cardiac imaging has included Tc-99m Annexin imaging to visualize myocardial apoptosis, but is now usually associated with gene therapy and cell-based therapy. Cardiac gene therapy was not successful so far but cardiac reporter gene imaging was made possible using HSV-TK (herpes simplex virus thymidine kinase) and F-18 FHBG (fluoro-hydroxymethylbutyl guanine) or I-124 FIAU (fluoro-deoxyiodo-arabino-furanosyluracil). Gene delivery was performed by needic injection with or without catheter guidance. Tk expression did not last longer than 2 weeks in myocardium. Cell-based therapy of ischemic heart or failing heart looks promising, but biodistribution and differentiation of transplanted cells are not known. Reporter genes can be transfected to the stem/progenitor cells and cells containing these genes can be transplanted to the recipients using catheter-based purging or injection. Repeated imaging should be available and if promoter are varied to let express reporter transgenes, cellular (trans)differentiation can be studied. NIS (sodium iodide symporter) or D2R receptor genes are promising in this aspect.

• BMB Reports
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• 제54권9호
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• pp.464-469
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• 2021

Cardiomyocyte differentiation occurs through complex and finely regulated processes including cardiac lineage commitment and maturation from pluripotent stem cells (PSCs). To gain some insight into the genome-wide characteristics of cardiac lineage commitment, we performed transcriptome analysis on both mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs) at specific stages of cardiomyocyte differentiation. Specifically, the gene expression profiles and the protein-protein interaction networks of the mESC-derived platelet-derived growth factor receptor-alpha (PDGFRα)⁺ cardiac lineage-committed cells (CLCs) and hiPSC-derived kinase insert domain receptor (KDR)⁺ and PDGFRα⁺ cardiac progenitor cells (CPCs) at cardiac lineage commitment were compared with those of mesodermal cells and differentiated cardiomyocytes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the genes significantly upregulated at cardiac lineage commitment were associated with responses to organic substances and external stimuli, extracellular and myocardial contractile components, receptor binding, gated channel activity, PI3K-AKT signaling, and cardiac hypertrophy and dilation pathways. Protein-protein interaction network analysis revealed that the expression levels of genes that regulate cardiac maturation, heart contraction, and calcium handling showed a consistent increase during cardiac differentiation; however, the expression levels of genes that regulate cell differentiation and multicellular organism development decreased at the cardiac maturation stage following lineage commitment. Additionally, we identified for the first time the protein-protein interaction network connecting cardiac development, the immune system, and metabolism during cardiac lineage commitment in both mESC-derived PDGFRα⁺ CLCs and hiPSC-derived KDR⁺PDGFRα⁺ CPCs. These findings shed light on the regulation of cardiac lineage commitment and the pathogenesis of cardiometabolic diseases.

• 생명과학회지
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• 제30권7호
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• pp.651-659
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• 2020

허혈성 심혈관질환은 전 세계적으로 치사율이 높은 질병 중 하나이다. 이를 치료하기 위해 수술적 방법이 시행되고 있으나, 손상된 심근조직 회복의 어려움과 수술 후 부작용의 한계가 남아있다. 이러한 한계점을 극복하기 위해, 최근 줄기세포를 기반으로 한 심혈관질환의 세포치료제가 각광받고 있는데 그 중에서도 특히 혈관내피전구세포(EPC)는 높은 증식능과 분화능을 기반으로 손상된 혈관을 재생하고, 주변 조직의 재생을 돕는다는 장점이 있다. 또, EPC는 임상적으로 안전하며, 환자의 심근 기능을 회복시켜주기에 잠재적인 심혈관질환 치료제로서의 가능성이 대두되었다. 하지만, 환자 유래 EPC를 이용한 치료법은, 고령, 흡연 여부, 기저질환 등의 이유로 환자의 EPC 기능이 저하되어 있어, 그 치료 효능을 기대하기 어렵다. 따라서, 최근에는 세포 프라이밍 기법, 오가노이드 배양법과 같이 EPC의 생리학적 활성도를 올리는 체외 배양법의 개발과 3D 바이오프린팅 기법을 이용한 EPC의 이식 효율을 높여 치료 효능을 개선시킬 수 있는 새로운 접근법이 연구되고 있다. 본 연구에서는 EPC의 특징과 세포치료제로서의 임상적용 가능성에 대해 살펴보고자 한다.

• 한국동물생명공학회지
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• 제37권2호
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• pp.67-79
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• 2022

Currently, there is no treatment to reverse or cure heart failure caused by ischemic heart disease and myocardial infarction despite the remarkable advances in modern medicine. In addition, there is a lack of evidence regarding the existence of stem cells involved in the proliferation and regeneration of cardiomyocytes in adult hearts. As an alternative solution to overcome this problem, protocols for differentiating human pluripotent stem cell (hPSC) into cardiomyocyte have been established, which further led to the development of cell therapy in major leading countries in this field. Recently, clinical studies have confirmed the safety of hPSC-derived cardiac progenitor cells (CPCs). Although several institutions have shown progress in their research on cell therapy using hPSC-derived cardiomyocytes, the functions of cardiomyocytes used for transplantation remain to be those of immature cardiomyocytes, which poses a risk of graft-induced arrhythmias in the early stage of transplantation. Over the last decade, research aimed at achieving maturation of immature cardiomyocytes, showing same characteristics as those of mature cardiomyocytes, has been actively conducted using various approaches at leading research institutes worldwide. However, challenges remain in technological development for effective generation of mature cardiomyocytes with the same properties as those present in the adult hearts. Therefore, in this review, we provide an overview of the technological development status for maturation methods of hPSC-derived cardiomyocytes and present a direction for future development of maturation techniques.

• 대한방사선기술학회지:방사선기술과학
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• 제37권2호
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• pp.109-116
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• 2014

본 연구에서는 관상동맥 중재술로 관상동맥 약물방출 스텐트(drug-eluting stent, DES) 삽입 후 스텐트 골절에 대한 임상적 특성, 결과 및 예후에 대하여 연구하였다. 약물방출 스텐트 시술을 받고 추적 관상동맥조영술을 실시한 4,701명 환자에서 스텐트 골절이 발생한 환자는 32명(남:여=19:13, 평균연령 $62.44{\pm}9.8$세, 0.68%)이었다. DES의 종류별 스텐트 골절의 빈도는 SES(sirolimus- eluting stents) 19(59.4%), PES(paclitaxel-eluting stents) 9명(28.1%), BES(biolimus A9-eluting stents) 2명(6.3%), EES(everolimus-eluting stents) 1명(3.1%), EPC(endothelial progenitor cell capture stent) 1명(3.1%), ZES(zotarolimus-eluting stents) 0명(0%) 이었다. 표적 병변은 우관상동맥 13명(40.6%) 좌전하행지 16명(50.0%), 좌회선지 3명(9.4%)이었다. 각 혈관의 병변 형태는 복잡병변인 B2, C형이 25명(69.4%)이었다. 스텐트 골절 환자 중 스텐트 내 협착은 17명(53.1%)이었으며, 스텐트 골절 병변에 대한 치료는 내과적 관찰 16명(50.0%), 동종의 관상동맥 DES 시술 3명(9.4%), 이종의 관상동맥 DES 시술 10명(31.3%), 관상동맥 풍선 확장술 3명(9.4%)이었다. 추적검사에서는 $32.9{\pm}12.4$개월 동안 스텐트 골절로 인한 사망을 포함한 심장사는 발생하지 않았다. 결론적으로 관상동맥 중재술로 관상동맥 DES를 시술받은 추적관찰 대상 환자에서 3.7년 추적관찰 기간 동안 스텐트 골절 발생률은 0.68%로 나타났으며, PES보다 SES에서 많은 발생 빈도를 보였다. 좌전하행지와 복잡병변에 대한 시술 후 스텐트 골절이 많이 발생하였다. 또한 스텐트 골절 정도와 협착 병변이 중대한 경우에만 관상동맥 중재술을 실시하였으며, 추적관찰 기간 중 스텐트 골절이 있는 환자는 병용 항혈소판 요법을 지속적으로 투여하였다. 특히 사망을 포함한 주요 심장사건에 관련하여 스텐트 골절과 연관된 심장사의 발생률은 매우 낮은 것으로 나타났다. 본 연구를 통해서 스텐트가 가지고 있는 특성 스텐트 디자인이 폐쇄형(closed cell) 디자인 SES에서 발생 빈도가 높음을 제시함으로써 스텐트 개발에 도움이 될 거라 판단된다.