Development of composite functional tissue sheets using hiPSC-CMs and hADSCs to improve the cardiac function after myocardial infarction.

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been widely used in therapy of ischemic heart disease. However, there are still remaining issues that limit the therapeutic efficacy, such as immune rejection and low retention of hiPSC-CMs. Human adipose mesenchymal stromal cells (hADSCs) have been reported to be able to regulate the immune response, promote angiogenesis and promote the maturation of hiPSC-CMs. In this study, we co-cultured these two types of cells on fiber scaffold made of biodegradable poly (D,L-lactic-co-glycolic acid) (PLGA) polymer for several days to develop a composited 3D cardiac tissue sheet. As expected, the cells formed 231.00 ± 15.14 µm thickness tissue, with improved organization, alignment, ECM condition, contractile ability, and paracrine function compared to culture hiPSC-CMs only on PLGA fiber. Furthermore, the composited 3D cardiac tissue sheet significantly promoted the engraftment and survival after transplantation. The composited 3D cardiac tissue sheet also increased cardiac function, attenuated ventricular remodeling, decreased fibrosis, and enhanced angiogenesis in rat myocardial infarction model, indicating that this strategy wound be a promising therapeutic option in the clinical scenario.

Skeletal Myoblast Cells Enhance the Function of Transplanted Islets in Diabetic Mice.

Islet transplantation (ITx) is an established and safe alternative to pancreas transplantation for type 1 diabetes mellitus (T1DM) patients. However, most ITx recipients lose insulin independence by 3 years after ITx due to early graft loss, such that multiple donors are required to achieve insulin independence. In the present study, we investigated whether skeletal myoblast cells could be beneficial for promoting angiogenesis and maintaining the differentiated phenotypes of islets. In vitro experiments showed that the myoblast cells secreted angiogenesis-related cytokines (vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and stromal-derived factor-1α (SDF-1α)), contributed to maintenance of differentiated islet phenotypes, and enhanced islet cell insulin secretion capacity. To verify these findings in vivo, we transplanted islets alone or with myoblast cells under the kidney capsule of streptozotocin-induced diabetic mice. Compared with islets alone, the group bearing islets with myoblast cells had a significantly lower average blood glucose level. Histological examination revealed that transplants with islets plus myoblast cells were associated with a significantly larger insulin-positive area and significantly higher number of CD31-positive microvessels compared to islets alone. Furthermore, islets cotransplanted with myoblast cells showed JAK-STAT signaling activation. Our results suggest two possible mechanisms underlying enhancement of islet graft function with myoblast cells cotransplantation: "indirect effects" mediated by angiogenesis and "direct effects" of myoblast cells on islets via the JAK-STAT cascade. Overall, these findings suggest that skeletal myoblast cells enhance the function of transplanted islets, implying clinical potential for a novel ITx procedure involving myoblast cells for patients with diabetes.

Application of a laparoscopic device for cell-derived sheet transplantation on the liver in a porcine model.

BACKGROUND: Cell-derived sheets are of global interest for regenerative therapy. Transplanting a sheet for abdominal organs requires a device for laparoscopic delivery to minimize invasiveness. Here, using a porcine model, we aimed to confirm the feasibility of a device developed to deliver sheets to the thoracic cavity in a laparoscopic transplantation procedure. MATERIAL AND METHODS: We used the device to transplant human skeletal myoblast cell sheets onto the liver and measured extra-corporeal, intra-abdominal, and total procedure times for sheet transplantation. Tissues, including the liver and the sheet, were collected two days after transplantation and analyzed histologically. RESULTS: In all experiments (n = 27), all sheets were successfully placed at target locations. The mean (± standard deviation) extra-corporeal, intra-abdominal, and total procedure times were 44 ± 29, 33 ± 12, and 77 ± 36 s, respectively. We found no difference between the two surgeons in procedure times. Histological analyses showed no liver damage with the transplantation and that sheets were transplanted closely onto the liver tissue without gaps. CONCLUSION: We confirmed the feasibility of a simple universal device to transplant cell-derived sheets via laparoscopic surgery. This device could support a minimally invasive procedure for sheet transplantation.

Pre-clinical evaluation of the efficacy and safety of human induced pluripotent stem cell-derived cardiomyocyte patch.

BACKGROUND: Cell- or tissue-based regenerative therapy is an attractive approach to treat heart failure. A tissue patch that can safely and effectively repair damaged heart muscle would greatly improve outcomes for patients with heart failure. In this study, we conducted a preclinical proof-of-concept analysis of the efficacy and safety of clinical-grade human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) patches. METHODS: A clinical-grade hiPSC line was established using peripheral blood mononuclear cells from a healthy volunteer that was homozygous for human leukocyte antigens. The hiPSCs were differentiated into cardiomyocytes. The obtained hiPSC-CMs were cultured on temperature-responsive culture dishes for patch fabrication. The cellular characteristics, safety, and efficacy of hiPSCs, hiPSC-CMs, and hiPSC-CM patches were analyzed. RESULTS: The hiPSC-CMs expressed cardiomyocyte-specific genes and proteins, and electrophysiological analyses revealed that hiPSC-CMs exhibit similar properties to human primary myocardial cells. In vitro and in vivo safety studies indicated that tumorigenic cells were absent. Moreover, whole-genome and exome sequencing revealed no genomic mutations. General toxicity tests also showed no adverse events posttransplantation. A porcine model of myocardial infarction demonstrated significantly improved cardiac function and angiogenesis in response to cytokine secretion from hiPSC-CM patches. No lethal arrhythmias were observed. CONCLUSIONS: hiPSC-CM patches are promising for future translational research and may have clinical application potential for the treatment of heart failure.

Development of a thick and functional human adipose-derived stem cell tissue sheet for myocardial infarction repair in rat hearts.

BACKGROUND: Heart failure (HF) is a major cause of death worldwide. The most effective treatment for HF is heart transplantation, but its use is limited by the scarcity of donor hearts. Recently, stem cell-based therapy has emerged as a promising approach for treating myocardial infarction. Our research group has been investigating the use of human induced pluripotent stem cell-derived cardiomyocyte patches as a potential therapeutic candidate. We have successfully conducted eight cases of clinical trials and demonstrated the safety and effectiveness of this approach. However, further advancements are necessary to overcome immune rejection and enhance therapeutic efficacy. In this study, we propose a novel and efficient technique for constructing mesenchymal stem cell (MSC) tissue sheets, which can be transplanted effectively for treating myocardial infarction repair. METHODS: We applied a one-step method to construct the human adipose-derived mesenchymal stem cell (hADSC) tissue sheet on a poly(lactic-co-glycolic acid) fiber scaffold. Histology, immunofluorescence, and paracrine profile assessment were used to determine the organization and function of the hADSC tissue sheet. Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function, fibrosis area, angiogenesis, and left ventricular remodeling. RESULTS: In vitro, the hADSC tissue sheet showed great organization, abundant ECM expression, and increased paracrine secretion than single cells. In vivo, the hADSC tissue sheet group demonstrated improved cardiac functional recovery, less ventricular remodeling, decreased fibrosis, and enhanced angiogenesis than the MI group. CONCLUSIONS: We developed thick and functional hADSC tissue sheets via the one-step strategy. The hADSC tissue sheet showed excellent performance in treating myocardial infarction in the rat model.