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Thư viện số Văn Lang: Etiology and Morphogenesis of Congenital Heart Disease: From Gene Function and Cellular Interaction to Morphology

Nguyễn Gia Hào

Academic year: 2023

Chia sẻ "Thư viện số Văn Lang: Etiology and Morphogenesis of Congenital Heart Disease: From Gene Function and Cellular Interaction to Morphology"


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We have used a combination of key cardiac regulatory factors to induce direct reprogramming of cardiac fibroblasts into cardiomyocyte-like cells with global gene expression and cardiomyocyte-like electrical activity. We ultimately found that a combination of three transcription factors—Gata4, Mef2c, and Tbx5 (GMT)—could convert ~15% of cardiac fibroblasts into αMHC-EGFP-positive cells, which we termed CM-like cells. induced (iCM) [5. ]. 24] successfully reprogrammed cardiac fibroblasts into iCM in vivo by introducing GMT into the heart of immunosuppressed mice with a single polycistronic retrovirus, which contains GMT with self-cleaving 2A peptides.

8] found that the introduction of GMT and Hand2 in vivo could convert cardiac fibroblasts directly into iCMs and also improve function and reduce scarring.

Fig. 1.1 In situ reprogramming of fibroblasts to cardiomyocytes. Representative histologic sections from mouse hearts treated with dsRed or Gata4/Mef2c/Tbx5 containing retroviral vectors injected into the myocardium after coronary ligation
Fig. 1.1 In situ reprogramming of fibroblasts to cardiomyocytes. Representative histologic sections from mouse hearts treated with dsRed or Gata4/Mef2c/Tbx5 containing retroviral vectors injected into the myocardium after coronary ligation

Origin of the Epicardium

Future therapeutic strategies may be possible that address cell-autonomous-based and signaling capabilities of the mature epicardium.

Epicardium-Derived Cells (EPDCs)

Heterogeneity of Epicardial Cells .1 The Cardiac Fibroblast


Congenital and Adult Cardiac Disease

However, in animal models, it is possible to associate the epicardium with certain heart defects and diseases. The most important cardiomyopathy resulting from abnormal EPDC function is primary noncompaction left ventricular cardiomyopathy [4], which shows a spongy myocardium that usually involves the ventricular septum. In terms of congenital heart defects, spongy ventricular septum can be associated with muscular VSDs.

Clinically, it has been hypothesized that the genetically determined long QT syndrome is associated with abnormal Purkinje fiber function. Indirectly, the abnormal formation of the fibrous annulus with persistent accessory pathways may result in reentry tachycardias. Furthermore, abnormal differentiation including defective undermining of the leaflet resembles Ebstein's anomaly in the tricuspid valve as observed in combination with accessory pathways [4].

EPDCs of aEP origin are found in the outflow tract pads (Figure 2.2), likely acting through Notch signaling to influence bicuspid aortic valve formation. Experimental studies that interfere with the normal development of coronary arteries cause a number of malformations that link congenital variations of human patterns to abnormal ventriculo-coronary-artery communication (fistulas). Fistulas detected in avian models with absent coronary artery orifices in the aorta [20], which resemble coronary malformations found in pulmonary atresia without VSD, are thought to be primary coronary vascular disease [21].

Cardiovascular Repair

PEO inhibition in chick embryos demonstrated deficient atrioventricular isolation, delaying the shift from a base-to-peak conduction to a peak-to-base conduction [17]. Injection of these adult human EPDCs into immune-incompetent mice resulted in a marked improvement in cardiac function [24], indicative of recovery. Combined injection with adult human cardiac muscle progenitor cells (CMPCs) targeted to induce cardiomyocyte regeneration [25], showing an additive effect on remodeling, although no new cardiac cell types (endothelial cells, fibroblasts, SMCs or cardiomyocytes) could be traced back to human origin.

Future Directions and Clinical Applications

Fate genetic mapping demonstrates the contribution of epicardium-derived cells to mammalian cardiac annulus fibrosis. Epicardial-derived cells are important for the proper development of Purkinje fibers in the avian heart. Persistence of functional atrioventricular accessory pathways in post-septated embryonic avian hearts: implications for morphogenesis and functional maturation of the cardiac conduction system.

The pathogenesis of atrial and atrioventricular septal defects with special emphasis on the role of the dorsal mesenchymal process. Preservation of left ventricular function and attenuation of remodeling after transplantation of human epicardium-derived cells into the infarcted mouse heart. A new direction for cardiac regeneration therapy: application of synergistically acting epicardium-derived cells and cardiomyocyte progenitor cells.

Direct injection of bone marrow-derived cells and isolated skeletal myoblasts has already been used clinically as a method to improve cardiac function by repairing cardiac muscle cells and blood vessels. Our lab proposed an original tissue engineering technology called “cell sheet engineering” that stacks cell sheets to reconstruct functional 3D tissues. Transplantation of cell sheets has already been shown to heal damaged hearts, and it seems clear that the field of cell tissue engineering can offer realistic treatment for patients with severe heart disorders.


In recent years, regenerative medicine, which uses cells to treat tissue defects, has been in the spotlight as a new treatment for severe heart failure. The research into reconstructing functional three-dimensional (3D) heart grafts using tissue engineering methods is now also being addressed as a next-generation treatment. Given these challenges with current technologies, regenerative therapies are being explored as an alternative approach and offer new possibilities for the repair of a damaged heart.

Recently, the direct injection of autologous skeletal myoblasts or bone marrow-derived cells has been investigated in clinical trials as an alternative cell source for cardiac muscle cells [1-3]. The direct injection of the dissociated cells has been found to be somewhat effective, but it is often difficult to control the shape, size or position of implanted cells. In an effort to solve these problems, research has started into advanced therapies using functional tissue produced by artificial heart transplants.

Over the past decade, several studies have demonstrated that bioengineered cardiac tissues can improve cardiac function in animal models of heart failure [4]. In this review, we discuss the progress of myocardial regeneration research with a focus on our original approach using cell sheet engineering.

Cell Sheet Engineering

Cardiac Tissue Reconstruction

Cell Sheet Transplantation in Small Animal Models

Cell Sheet Transplantation in Preclinical and Clinical Studies


Endothelial cell co-culture in tissue-engineered cardiomyocyte sheets increases neovascularization and improves cardiac function of ischemic hearts. Cardiac cell sheet transplantation improves damaged heart function via superior cell survival compared with dissociated cell injection. Memon IA, Sawa Y, Fukushima N, Matsumiya G, Miyagawa S, Taketani S, Sakakida SK, Kondoh H, Aleshin AN, Shimizu T, Okano T, Matsuda H.

Bel A, Planat-Bernard V, Saito A, Bonnevie L, Bellamy V, Sabbah L, Bellabas L, Brinon B, Vanneaux V, Pradeau P, Peyrard S, Larghero J, Pouly J, Binder P, Garcia S, Shimizu T, Sawa Y, Okano T, Bruneval P, Desnos M, Hagege AA, Casteilla L, Puceat M, Menasche P. Composite cell sheets: a further step towards safe and effective myocardial regeneration from embryonic stem cell-derived cardiac progenitors. . Tissue-engineered myoblast sheets improved cardiac function sufficiently to interrupt lvas in a patient with dcm: a case report.

To this end, we developed a novel method to generate human induced pluripotent stem cells (iPSCs) from circulating human T lymphocytes using Sendai virus containing Yamanaka factors. To establish an efficient cardiac differentiation protocol, we screened factors expressed in the future heart site of early mouse embryos and identified several growth factors and cytokines that can induce cardiomyocyte differentiation and proliferation. Subsequent transcriptome and metabolome analysis on undifferentiated stem cells and cardiomyocytes to engineer a specific metabolic environment for cardiomyocyte selection revealed completely different mechanisms of glucose and lactate metabolism.


Cardiac Differentiation from Human iPSCs

6] screened a library of chemical compounds approved by the US Food and Drug Administration (FDA) and found that ascorbic acid efficiently induces cardiac differentiation. Several studies have shown that various combinations of cardiac development-related proteins, including BMP, activin, Wnt, BMP inhibitor, and Wnt inhibitor, induce cardiomyocytes from ESCs [7–10] . We reported that the context-dependent differential action of BMPs in cardiomyocyte induction is explained by the local action of Noggin and other BMP inhibitors, and accordingly we developed a protocol to induce cardiac differentiation of mouse ESCs by transient administration of Noggin [9].

However, to obtain hundreds of millions of cardiomyocytes, it is necessary to establish a cardiac differentiation method that is both efficient and cost-effective due to the many expensive recombinant protein factors used. 11] screened small molecule compounds to identify those that significantly enhance cardiac differentiation induction, and they revealed some inhibitors of canonical Wnt signaling as candidates. Several studies then showed that induction techniques in ESCs could also be applied to iPSCs, although differentiation efficiency was suggested to be inferior compared to ESCs.

Furthermore, to efficiently obtain large quantities of cardiomyocytes at low cost, it is necessary to continue refining efficient cardiac differentiation systems combined with the use of small molecule compounds. However, despite the improvement in cardiac differentiation efficiency, it is inevitable that human PSC derivatives contain not only cardiomyocytes, but also undifferentiated stem cells and/or noncardiac cells, because all PSCs cannot differentiate into cardiomyocytes. Therefore, to confirm safety after transplantation, it is necessary to remove non-cardiac cells and undifferentiated stem cells that can cause tumors.

Nongenetic Methods for Purifying Cardiomyocytes

However, since such differentiation efficiency varies greatly among different cell lines [12], further research is needed in the future. Furthermore, we were able to establish a practical culture system to generate significant numbers of purified cardiomyocytes by combining a massive suspension culture system with a metabolic selection medium (Hemmi et al.

Transplantation of Human PSC-Derived Cardiomyocytes

Thus, careful evaluation of the efficacy and safety of human iPSC-derived cardiomyocytes in cell transplantation over the longer term should be ongoing.

Future Directions

Human embryonic stem cell-derived cardiomyocytes in pro-survival factors improve the function of infarcted rat hearts. Transient inhibition of BMP signaling by Noggin induces cardiomyocyte differentiation of mouse embryonic stem cells. Stage-specific optimization of actin/nodal and BMP signaling promotes cardiac differentiation of murine and human pluripotent stem cell lines.

A small molecule that promotes cardiac differentiation of human pluripotent stem cells under defined, cytokine- and xeno-free conditions. SIRPA is a specific cell surface marker for the isolation of cardiomyocytes derived from human pluripotent stem cells. Distinct metabolic flow enables large-scale purification of mouse and human pluripotent stem cell-derived cardiomyocytes.

In searching for remedial etiologies for congenital heart disease (CHD), we focused on identifying interactive signaling pathways or “hubs” in which mutations disrupt fundamental cell biological functions in cardiac progenitor cells in a lineage-specific manner. We discuss them in the context of valve and septal development and the lineages from which their progenitors originate. Heart defects • Valves • Septa • Matricellular proteins • Periostin • Cell signaling • Kinases • Filamin A • Hematopoietic stem cells • Fibroblast • Lineage • Genetic engineering.

Introduction .1 Emerging Concepts

Searching for Candidate Signaling Hubs in Heart Development

Hình ảnh

Fig. 1.1 In situ reprogramming of fibroblasts to cardiomyocytes. Representative histologic sections from mouse hearts treated with dsRed or Gata4/Mef2c/Tbx5 containing retroviral vectors injected into the myocardium after coronary ligation
Fig. 2.1 Four-chamber view of a mouse heart (ED12.5) immunostained for WT1. Note brown cells lining the pericardial cavity (PC), including the epicardium
Fig. 2.2 Cross section of aorta (Ao) and right ventricular outflow tract (R-OFT). Aortic epicar- epicar-dium is densely packed and cuboid (arrows), whereas cEP is squamous (short arrows)
Fig. 3.1 Cell sheet engineering. Using temperature-responsive dishes, cultured cells can be harvested as intact contiguous sheets by simple temperature reduction without proteolytic treatment

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