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1.
Theranostics ; 11(16): 7879-7895, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335970

RESUMO

Rationale: Previous studies have shown that human embryonic stem cell-derived cardiomyocytes improved myocardial recovery when administered to infarcted pig and non-human primate hearts. However, the engraftment of intramyocardially delivered cells is poor and the effectiveness of clinically relevant doses of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in large animal models of myocardial injury remains unknown. Here, we determined whether thymosin ß4 (Tb4) could improve the engraftment and reparative potency of transplanted hiPSC-CMs in a porcine model of myocardial infarction (MI). Methods: Tb4 was delivered from injected gelatin microspheres, which extended the duration of Tb4 administration for up to two weeks in vitro. After MI induction, pigs were randomly distributed into 4 treatment groups: the MI Group was injected with basal medium; the Tb4 Group received gelatin microspheres carrying Tb4; the CM Group was treated with 1.2 × 108 hiPSC-CMs; and the Tb4+CM Group received both the Tb4 microspheres and hiPSC-CMs. Myocardial recovery was assessed by cardiac magnetic resonance imaging (MRI), arrhythmogenesis was monitored with implanted loop recorders, and tumorigenesis was evaluated via whole-body MRI. Results: In vitro, 600 ng/mL of Tb4 protected cultured hiPSC-CMs from hypoxic damage by upregulating AKT activity and BcL-XL and promoted hiPSC-CM and hiPSC-EC proliferation. In infarcted pig hearts, hiPSC-CM transplantation alone had a minimal effect on myocardial recovery, but co-treatment with Tb4 significantly enhanced hiPSC-CM engraftment, induced vasculogenesis and the proliferation of cardiomyocytes and endothelial cells, improved left ventricular systolic function, and reduced infarct size. hiPSC-CM implantation did not increase incidence of ventricular arrhythmia and did not induce tumorigenesis in the immunosuppressed pigs. Conclusions: Co-treatment with Tb4-microspheres and hiPSC-CMs was safe and enhanced the reparative potency of hiPSC-CMs for myocardial repair in a large-animal model of MI.


Assuntos
Infarto do Miocárdio/terapia , Miócitos Cardíacos/metabolismo , Timosina/farmacologia , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , China , Modelos Animais de Doenças , Células Endoteliais/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/patologia , Regeneração , Transplante de Células-Tronco/métodos , Suínos , Timosina/metabolismo , Timosina/fisiologia
2.
Front Cell Dev Biol ; 9: 667252, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34136485

RESUMO

Induced pluripotent stem cells derived cells (iPSCs) not only can be used for personalized cell transfer therapy, but also can be used for modeling diseases for drug screening and discovery in vitro. Although prior studies have characterized the function of rodent iPSCs derived endothelial cells (ECs) in diabetes or metabolic syndrome, feature phenotypes are largely unknown in hiPSC-ECs from patients with diabetes. Here, we used hiPSC lines from patients with type 2 diabetes mellitus (T2DM) and differentiated them into ECs (dia-hiPSC-ECs). We found that dia-hiPSC-ECs had disrupted glycine homeostasis, increased senescence, and impaired mitochondrial function and angiogenic potential as compared with healthy hiPSC-ECs. These signature phenotypes will be helpful to establish dia-hiPSC-ECs as models of endothelial dysfunction for understanding molecular mechanisms of disease and for identifying and testing new targets for the treatment of endothelial dysfunction in diabetes.

3.
Exp Anim ; 70(4): 498-507, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34135271

RESUMO

Transverse aortic constriction (TAC) has been widely used to study cardiac hypertrophy, fibrosis, diastolic dysfunction, and heart failure in rodents. Few studies have been reported in preclinical animal models. The similar physiology and anatomy between non-human primates (NHPs) and humans make NHPs valuable models for disease modeling and testing of drugs and devices. In the current study, we aimed to establish a TAC model in NHPs and characterize the structural and functional profiles of the heart after TAC. A non-absorbable suture was placed around the aorta between the brachiocephalic artery and left common carotid artery to create TAC. NHPs were divided into 2 groups according to pressure gradient (PG): the Mild Group (PG=31.01 ± 12.40 mmHg, n=3) and the Moderate Group (PG=53.00 ± 9.37 mmHg, n=4). At 4 weeks after TAC, animals in both TAC groups developed cardiac hypertrophy: enlarged myocytes and increased wall thickness of the left ventricular (LV) anterior wall. Although both TAC groups had normal systolic function that was similar to a Sham Group, the Moderate Group showed diastolic dysfunction that was associated with more severe cardiac fibrosis, as evidenced by a reduced A wave velocity, large E wave velocity/A wave velocity ratio, and short isovolumic relaxation time corrected by heart rate. Furthermore, no LV arrhythmia was observed in either animal group after TAC. A diastolic dysfunction model with cardiac hypertrophy and fibrosis was successfully developed in NHPs.


Assuntos
Aorta Torácica/fisiopatologia , Ventrículos do Coração/fisiopatologia , Coração/fisiopatologia , Função Ventricular Esquerda/fisiologia , Animais , Constrição , Modelos Animais de Doenças , Feminino , Macaca fascicularis , Masculino
4.
Circulation ; 138(24): 2798-2808, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30030417

RESUMO

BACKGROUND: The adult mammalian heart has limited ability to repair itself after injury. Zebrafish, newts, and neonatal mice can regenerate cardiac tissue, largely by cardiac myocyte (CM) proliferation. It is unknown whether hearts of young large mammals can regenerate. METHODS: We examined the regenerative capacity of the pig heart in neonatal animals (ages 2, 3, or 14 days postnatal) after myocardial infarction or sham procedure. Myocardial scar and left ventricular function were determined by cardiac magnetic resonance imaging and echocardiography. Bromodeoxyuridine pulse-chase labeling, histology, immunohistochemistry, and Western blotting were performed to study cell proliferation, sarcomere dynamics, and cytokinesis and to quantify myocardial fibrosis. RNA-sequencing was also performed. RESULTS: After myocardial infarction, there was early and sustained recovery of cardiac function and wall thickness in the absence of fibrosis in 2-day-old pigs. In contrast, older animals developed full-thickness myocardial scarring, thinned walls, and did not recover function. Genome-wide analyses of the infarct zone revealed a strong transcriptional signature of fibrosis in 14-day-old animals that was absent in 2-day-old pigs, which instead had enrichment for cytokinesis genes. In regenerating hearts of the younger animals, up to 10% of CMs in the border zone of the myocardial infarction showed evidence of DNA replication that was associated with markers of myocyte division and sarcomere disassembly. CONCLUSIONS: Hearts of large mammals have regenerative capacity, likely driven by cardiac myocyte division, but this potential is lost immediately after birth.


Assuntos
Coração/fisiologia , Infarto do Miocárdio/patologia , Animais , Animais Recém-Nascidos , Citocinese/genética , Ecocardiografia , Fibrose , Imagem Cinética por Ressonância Magnética , Infarto do Miocárdio/diagnóstico por imagem , Miocárdio/patologia , Miócitos Cardíacos/fisiologia , Regeneração , Suínos , Troponina I/análise , Função Ventricular Esquerda
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