enhancing-engraftment-human-induced-pluripotent-stem-cell-derived

Enhancing the Engraftment of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes via a Transient Inhibition of Rho Kinase Activity

A crucial factor in improving cellular therapy effectiveness for myocardial regeneration is to safely and efficiently increase the cell engraftment rate. ...

University of Alabama at Birmingham

The effectiveness of transplanted, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) for treatment of ischemic myocardial injury is limited by the exceptionally low engraftment rate.

CCND2 Overexpression Enhances the Regenerative Potency of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Remuscularization of Injured Ventricle.

Vascular endothelial growth factor (VEGF) is a well-characterized proangiogenic cytokine that has been shown to promote neovascularization in hearts of patients with ischemic heart disease but can also lead to adverse effects depending on the dose and mode of delivery. We investigated whether prolonged exposure to a low dose of VEGF could be achieved by encapsulating VEGF in polylactic coglycolic acid nanoparticles and whether treatment with VEGF-containing nanoparticles improved cardiac function and protected against left ventricular remodeling in the hearts of mice with experimentally induced myocardial infarction. Polylactic coglycolic acid nanoparticles with a mean diameter of ~113 nm were generated via double emulsion and loaded with VEGF; the encapsulation efficiency was 53.5 ± 1.7% (107.1 ± 3.3 ng VEGF/mg nanoparticles). In culture, VEGF nanoparticles released VEGF continuously for at least 31 days, and in a murine myocardial infarction model, VEGF nanoparticle administration was associated with significantly greater vascular density in the peri-infarct region, reductions in infarct size, and improvements in left ventricular contractile function 4 wk after treatment. Thus, our study provides proof of principle that nanoparticle-mediated delivery increases the angiogenic and therapeutic potency of VEGF for the treatment of ischemic heart disease. NEW & NOTEWORTHY Vascular endothelial growth factor (VEGF) is a well-characterized proangiogenic cytokine but has a short half-life and a rapid clearance rate. When encapsulated in nanoparticles, VEGF was released for 31 days and improved left ventricular function in infarcted mouse hearts. These observations indicate that our new platform increases the therapeutic potency of VEGF.

VEGF nanoparticles repair the heart after myocardial infarction.

Rodent hearts can regenerate myocardium lost to apical resection or myocardial infarction for up to 7 days after birth, but whether a similar window for myocardial regeneration also exists in large mammals is unknown.

Regenerative Potential of Neonatal Porcine Hearts.

The effectiveness of cell-based treatments for regenerative myocardial therapy is limited by low rates of cell engraftment. Y-27632 inhibits Rho-associated protein kinase (ROCK), which regulates the cytoskeletal changes associated with cell adhesion, and has been used to protect cultured cells during their passaging. Here, we investigated whether preconditioning of cardiomyocytes, derived from human-induced pluripotent stem cells (hiPSC-CM), with Y-27632 improves their survival and engraftment in a murine model of acute myocardial infarction (MI).

Y-27632 preconditioning enhances transplantation of human-induced pluripotent stem cell-derived cardiomyocytes in myocardial infarction mice.

Increasing evidence suggests the consensus that direct  application of induced pluripotent stem cells (iPSCs) is infeasible may not be true.  Teratoma formation and fate were examined in 53 normal and disease conditions involving brain, lung, liver, kidney, islet, skin, hind limb, and arteries.  Using classic teratoma generation assays, which require iPSCs to be congregated and confined, all mouse, human, and individualized autologous monkey iPSCs tested formed teratoma, while iPSC-derived cells did not. Intravenously or topically-disseminated iPSCs did not form teratomas with doses up to 2.5×10 iPSCs/kg and observation times up to 18 months, regardless of host tissue type; autologous, syngeneic, or immune-deficient host animals; presence or absence of disease; disease type; iPSC induction method; commercial or self-induced iPSCs; mouse, human, or monkey iPSCs; frequency of delivery; and sex. Matrigel-confined, but not PBS-suspended, syngeneic iPSCs delivered into the peritoneal cavity or renal capsule formed teratomas. Intravenously administered iPSCs were therapeutic with a dose as low as 5×10/kg and some iPSCs differentiated into somatic cells in injured organs. Disseminated iPSCs trafficked into injured tissue and survived significantly longer in injured than uninjured organs. In disease-free animals, no intravenously administered cell differentiated into an unwanted long-lasting cell or survived as a quiescent stem cell. In coculture, the stem cell medium and dominant cell-type status were critical for iPSCs to form cell masses.  Teratoma can be easily and completely avoided by disseminating the cells. Direct  iPSC application is feasible and can be safe.

Direct  application of induced pluripotent stem cells is feasible and can be safe.

How natural or innate-like lymphocytes generate the capacity to produce IL-4 and other cytokines characteristic of type 2 immunity remains unknown. Invariant natural killer T (iNKT) cells differentiate in the thymus into NKT1, NKT2, and NKT17 subsets, similar to mature, peripheral CD4 T helper cells. The mechanism for this differentiation was not fully understood. Here, we show that NKT2 cells required higher and prolonged calcium (Ca ) signals and continuing activity of the calcium release-activated calcium (CRAC) channel, than their NKT1 counterparts. The sustained Ca entry via CRAC pathway in NKT2 cells was apparently mediated by ORAI and controlled in part by the large mitochondrial Ca uptake. Unique properties of mitochondria in NKT2 cells, including high activity of oxidative phosphorylation, may regulate mitochondrial Ca buffering in NKT2 cells. In addition, the low Ca extrusion rate may also contribute to the higher Ca level in NKT2 cells. Altogether, we identified ORAI-dependent Ca signaling connected with mitochondria and cellular metabolism, as a central regulatory pathway for the differentiation of NKT2 cells.

Calcium signals regulate the functional differentiation of thymic iNKT cells.

Innate-like T cells, including invariant NKT cells, mucosal-associated invariant T (MAIT) cells, and γ δ T (γδT) cells, are groups of unconventional T lymphocytes. They play important roles in the immune system. Because of the lack of Cre recombinase lines that are specific for innate-like T cells, pan-T cell Cre lines are often used to study innate-like T cells. In this study, we found that distal Lck promoter-driven Cre (dLckCre) in which the distal  gene promoter drives Cre expression in the late stage of thymocyte development has limited function in the innate-like T cells using  reporter. Innate-like T cells differentiate into mature functional subsets comparable to the CD4 Th subsets under homeostatic conditions. We further showed that dLckCre-expressing γδT cells are strongly biased toward γδT1 phenotype. Interestingly, the γδT cells residing in the epidermis and comprising the vast majority of dendritic epidermal T cells nearly all express dLckCre, indicating dLckCre is a useful tool for studying dendritic epidermal T cells. Taken together, these data suggest that  distal promoter has different activity in the conventional and unconventional T cells. The use of dLCKcre transgenic mice in the innate-like T cells needs to be guided by a reporter for the dLckCre function.

Distal  Promoter-Driven Cre Shows Cell Type-Specific Function in Innate-like T Cells.

Neutrophils are the most abundant leukocyte in human blood. They are critical for fighting infections and are involved in inflammatory diseases. Mitochondria are indispensable for eukaryotic cells, as they control the biochemical processes of respiration and energy production. Mitochondria in neutrophils have been underestimated since glycolysis is a major metabolic pathway for fuel production in neutrophils. However, several studies have shown that mitochondria are greatly involved in multiple neutrophil functions as well as neutrophil-related diseases. In this review, we focus on how mitochondrial components, metabolism, and related genes regulate neutrophil functions and relevant diseases.

Article	Year
CCND2 Overexpression Enhances the Regenerative Potency of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Remuscularization of Injured Ventricle. Circulation research\| PubMed ID: 29018036	2018
VEGF nanoparticles repair the heart after myocardial infarction. American journal of physiology. Heart and circulatory physiology\| PubMed ID: 29101176	2018
Regenerative Potential of Neonatal Porcine Hearts. Circulation\| PubMed ID: 30030418	2018
Y-27632 preconditioning enhances transplantation of human-induced pluripotent stem cell-derived cardiomyocytes in myocardial infarction mice. Cardiovascular research\| PubMed ID: 30107391	2019
Direct application of induced pluripotent stem cells is feasible and can be safe. Theranostics\| PubMed ID: 30662568	2019
Calcium signals regulate the functional differentiation of thymic iNKT cells. The EMBO journal\| PubMed ID: 34169542	2021
Distal Promoter-Driven Cre Shows Cell Type-Specific Function in Innate-like T Cells. ImmunoHorizons\| PubMed ID: 34583938	2021
Roles of mitochondria in neutrophils. Frontiers in immunology\| PubMed ID: 36081497	2022

Meng Zhao

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