Ultrastructural features of ischemic tissue following application of a bio-membrane based progenitor cardiomyocyte patch for myocardial infarction repair

Revolutionizing cardiovascular research: Human organoids as a Beacon of hope for understanding and treating cardiovascular diseases

Organoids, exhibiting the capability to undergo differentiation in specific in vitro growth environments, have garnered significant attention in recent years due to their capacity to recapitulate human organs with resemblant in vivo structures and physiological functions. This groundbreaking technology offers a unique opportunity to study human diseases and address the limitations of traditional animal models. Cardiovascular diseases (CVDs), a leading cause of mortality worldwide, have spurred an increasing number of researchers to explore the great potential of human cardiovascular organoids for cardiovascular research. This review initiates by elaborating on the development and manufacture of human cardiovascular organoids, including cardiac organoids and blood vessel organoids. Next, we provide a comprehensive overview of their applications in modeling various cardiovascular disorders. Furthermore, we shed light on the prospects of cardiovascular organoids in CVDs therapy, and unfold an in-depth discussion of the current challenges of human cardiovascular organoids in the development and application for understanding and treating CVDs.

A Concise Review on Induced Pluripotent Stem Cell-Derived Cardiomyocytes for Personalized Regenerative Medicine

The induced pluripotent stem cells (iPSCs) are derived from somatic cells by using reprogramming factors such as Oct4, Sox2, Klf4, and c-Myc (OSKM) or Oct4, Sox2, Nanog and Lin28 (OSNL). They resemble embryonic stem cells (ESCs) and have the ability to differentiate into cell lineage of all three germ-layer, including cardiomyocytes (CMs). The CMs can be generated from iPSCs by inducing embryoid bodies (EBs) formation and treatment with activin A, bone morphogenic protein 4 (BMP4), and inhibitors of Wnt signaling. However, these iPSC-derived CMs are a heterogeneous population of cells and require purification and maturation to mimic the in vivo CMs. The matured CMs can be used for various therapeutic purposes in regenerative medicine by cardiomyoplasty or through the development of tissue-engineered cardiac patches. In recent years, significant advancements have been made in the isolation of iPSC and their differentiation, purification, and maturation into clinically usable CMs. Newer small molecules have also been identified to substitute the reprogramming factors for iPSC generation as well as for direct differentiation of somatic cells into CMs without an intermediary pluripotent state. This review provides a concise update on the generation of iPSC-derived CMs and their application in personalized cardiac regenerative medicine. It also discusses the current limitations and challenges in the application of iPSC-derived CMs. Graphical abstract.

Potential Applications of Induced Pluripotent Stem Cells for Cardiovascular Diseases

Owning the high incidence and disability rate in the past decades, to be expected, cardiovascular diseases (CVDs) have become one of the leading death causes worldwide. Currently, induced pluripotent stem cells (iPSCs), with the potential to form fresh myocardium and improve the functions of damaged hearts, have been studied widely in experimental CVD therapy. Moreover, iPSC-derived cardiomyocytes (CMs), as novel disease models, play a significant role in drug screening, drug safety assessment, along with the exploration of pathological mechanisms of diseases. Furthermore, a lot of studies have been carried out to clarify the biological basis of iPSCs and its derived cells in the treatment of CVDs. Their molecular mechanisms were associated with release of paracrine factors, regulation of miRNAs, mechanical support of new tissues, activation of specific pathways and specific enzymes, etc. In addition, a few small chemical molecules and suitable biological scaffolds play positive roles in enhancing the efficiency of iPSC transplantation. This article reviews the development and limitations of iPSCs in CVD therapy, and summarizes the latest research achievements regarding the application of iPSCs in CVDs.

Heterogeneity of adult masseter muscle satellite cells with cardiomyocyte differentiation potential

Although resident cardiac stem cells have been reported, regeneration of functional cardiomyocytes (CMs) remains a challenge. The present study identifies an alternative progenitor source for CM regeneration without the need for genetic manipulation or invasive heart biopsy procedures. Unlike limb skeletal muscles, masseter muscles (MM) in the mouse head are developed from Nkx2-5 mesodermal progenitors. Adult masseter muscle satellite cells (MMSCs) display heterogeneity in developmental origin and cell phenotypes. The heterogeneous MMSCs that can be characterized by cell sorting based on stem cell antigen-1 (Sca1) show different lineage potential. While cardiogenic potential is preserved in Sca1+ MMSCs as shown by expression of cardiac progenitor genes (including Nkx2-5), skeletal myogenic capacity is maintained in Sca1- MMSCs with Pax7 expression. Sca1+ MMSC-derived beating cells express cardiac genes and exhibit CM-like morphology. Electrophysiological properties of MMSC-derived CMs are demonstrated by calcium transients and action potentials. These findings show that MMSCs could serve as a novel cell source for cardiomyocyte replacement.

Human iPS Cell-Derived Cardiac Tissue Sheets: a Platform for Cardiac Regeneration

Stem cell therapy is a promising therapeutic option for severe cardiac diseases that are resistant to conventional therapies. To overcome the unsatisfactory results of most clinical researches on stem cell injections to an injured heart, we are developing bioengineered cardiac tissue grafts using pluripotent stem cell-derived cardiomyocytes and vascular cells. We have validated the functional benefits of mouse embryonic stem cell-derived and human induced pluripotent stem cell-derived cardiac tissue sheets (CTSs) in a rat myocardial infarction model. We further showed enhanced functional recovery and engraftment efficiency leading to de novo myocardium upon transplanting thick multi-layered CTSs that had gelatin hydrogel microspheres between the layers. We anticipate that the combination of pluripotent stem cell biology and tissue engineering will contribute to future stem cell therapies for severe heart diseases.