Transplantation Of Pluripotent Stem Cells Research Articles

Transplantation of Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium in a Swine Model of Geographic Atrophy.

Background: The aim of this study was to test the feasibility and safety of subretinal transplantation of human induced pluripotent stem cell (hiPSC)-derived retinal pigment epithelium (RPE) cells into the healthy margins and within areas of degenerative retina in a swine model of geographic atrophy (GA). Methods: Well-delimited selective outer retinal damage was induced by subretinal injection of NaIO3 into one eye in minipigs (n = 10). Thirty days later, a suspension of hiPSC-derived RPE cells expressing green fluorescent protein was injected into the subretinal space, into the healthy margins, and within areas of degenerative retina. In vivo follow-up was performed by multimodal imaging. Post-mortem retinas were analyzed by immunohistochemistry and histology. Results: In vitro differentiated hiPSC-RPE cells showed a typical epithelial morphology, expressed RPE-related genes, and had phagocytic ability. Engrafted hiPSC-RPE cells were detected in 60% of the eyes, forming mature epithelium in healthy retina extending towards the border of the atrophy. Histological analysis revealed RPE interaction with host photoreceptors in the healthy retina. Engrafted cells in the atrophic zone were found in a patchy distribution but failed to form an epithelial-like layer. Conclusions: These results might support the use of hiPSC-RPE cells to treat atrophic GA by providing a housekeeping function to aid the overwhelmed remnant RPE, which might improve its survival and therefore slow down the progression of GA.

Generation of Monkey Induced Pluripotent Stem Cell-Derived Cartilage Lacking Major Histocompatibility Complex Class I Molecules on the Cell Surface.

Due to the poor capacity for articular cartilage to regenerate, its damage tends to result in progressively degenerating conditions such as osteoarthritis. To repair the damage, the transplantation of allogeneic human induced pluripotent stem cell (iPSC)-derived cartilage is being considered. However, although allogeneic cartilage transplantation is effective, immunological reactions can occur. One hypothetical solution is to delete the expression of major histocompatibility complex (MHC) class I molecules to reduce the immunological reactions. For this purpose, we deleted the β2 microglobulin (B2M) gene in a cynomolgus monkey (crab-eating monkey [Macaca fascicularis]) iPS cells (cyiPSCs) to obtain B2M−/− cyiPSCs using the CRISPR/Cas9 system. Western blot analysis confirmed B2M−/− cyiPSCs lacked B2M protein, which is necessary for MHC class I molecules to be transported to and expressed on the cell surface by forming multimers with B2M. Flow cytometry analysis revealed no B2M−/− cyiPSCs expressed MHC class I molecules on their surface. The transplantation of B2M−/− cyiPSCs in immunodeficient mice resulted in teratoma that contained cartilage, indicating that the lack of MHC class I molecules on the cell surface affects neither the pluripotency nor the chondrogenic differentiation capacity of cyiPSCs. By modifying the chondrogenic differentiation protocol for human iPSCs, we succeeded at differentiating B2M+/+ and B2M−/− cyiPSCs toward chondrocytes followed by cartilage formation in vitro, as indicated by histological analysis showing that B2M+/+ and B2M−/− cyiPSC-derived cartilage were positively stained with safranin O and expressed type II collagen. Flow cytometry analysis confirmed that MHC class I molecules were not expressed on the cell surface of B2M−/− chondrocytes isolated from B2M−/− cyiPSC-derived cartilage. An in vitro mixed lymphocyte reaction assay showed that neither B2M+/+ nor B2M−/− cyiPSC-derived cartilage cells stimulated the proliferation of allogeneic peripheral blood mononuclear cells. On the contrary, osteochondral defects in monkey knee joints that received allogeneic transplantations of cyiPSC-derived cartilage showed an accumulation of leukocytes with more natural killer cells around B2M−/− cyiPSC-derived cartilage than B2M+/+ cartilage, suggesting complex mechanisms in the immune reaction of allogeneic cartilage transplanted in osteochondral defects in vivo.Impact statementThe transplantation of allogeneic induced pluripotent stem cell (iPSC)-derived cartilage is expected to treat articular cartilage damage, although the effects of major histocompatibility complex (MHC) in immunological reactions have not been well studied. We succeeded at creating B2M−/− cynomolgus monkey (cy)iPSCs and cyiPSC-derived cartilage that lack MHC class I molecules on the cell surface. B2M−/− cyiPSC-derived cartilage cells did not stimulate the proliferation of allogeneic peripheral blood mononuclear cells in vitro. On the contrary, the transplantation of B2M−/− cyiPSC-derived cartilage into osteochondral defects in monkey knee joints resulted in survival of transplants and accumulation of leukocytes, including natural killer cells, suggesting complex mechanisms for the immune reaction.

Subretinal Transplantation of Human Embryonic Stem Cell-Derived Retinal Tissue in a Feline Large Animal Model.

Retinal degenerative (RD) conditions associated with photoreceptor loss such as age-related macular degeneration (AMD), retinitis pigmentosa (RP) and Leber Congenital Amaurosis (LCA) cause progressive and debilitating vision loss. There is an unmet need for therapies that can restore vision once photoreceptors have been lost. Transplantation of human pluripotent stem cell (hPSC)-derived retinal tissue (organoids) into the subretinal space of an eye with advanced RD brings retinal tissue sheets with thousands of healthy mutation-free photoreceptors and has a potential to treat most/all blinding diseases associated with photoreceptor degeneration with one approved protocol. Transplantation of fetal retinal tissue into the subretinal space of animal models and people with advanced RD has been developed successfully but cannot be used as a routine therapy due to ethical concerns and limited tissue supply. Large eye inherited retinal degeneration (IRD) animal models are valuable for developing vision restoration therapies utilizing advanced surgical approaches to transplant retinal cells/tissue into the subretinal space. The similarities in globe size, and photoreceptor distribution (e.g., presence of macula-like region area centralis) and availability of IRD models closely recapitulating human IRD would facilitate rapid translation of a promising therapy to the clinic. Presented here is a surgical technique of transplanting hPSC-derived retinal tissue into the subretinal space of a large animal model allowing assessment of this promising approach in animal models.

Efficient differentiation of human embryonic stem cells to retinal pigment epithelium under defined conditions

Age-related macular degeneration (AMD) is a highly prevalent form of blindness caused by loss death of cells of the retinal pigment epithelium (RPE). Transplantation of pluripotent stem cell (PSC)-derived RPE cells is considered a promising therapy to regenerate cell function and vision.ObjectiveThe objective of this study is to develop a rapid directed differentiation method for production of RPE cells from PSC which is rapid, efficient, and fully defined and produces cells suitable for clinical use.DesignA protocol for cell growth and differentiation from hESCs was developed to induce differentiation through screening small molecules which regulated a primary stage of differentiation to the eyefield progenitor, and then, a subsequent set of molecules to drive differentiation to RPE cells. Methods for cell plating and maintenance have been optimized to give a homogeneous population of cells in a short 14-day period, followed by a procedure to support maturation of cell function.ResultsWe show here the efficient production of RPE cells from human embryonic stem cells (hESCs) using small molecules in a feeder-free system using xeno-free/defined medium. Flow cytometry at day 14 showed ~ 90% of cells expressed the RPE markers MITF and PMEL17. Temporal gene analysis confirmed differentiation through defined cell intermediates. Mature hESC-RPE cell monolayers exhibited key morphological, molecular, and functional characteristics of the endogenous RPE.ConclusionThis study identifies a novel cell differentiation process for rapid and efficient production of retinal RPE cells directly from hESCs. The described protocol has utility for clinical-grade cell production for human therapy to treat AMD.

Cell therapy with hiPSC-derived RPE cells and RPCs prevents visual function loss in a rat model of retinal degeneration

Photoreceptor loss is the principal cause of blindness in retinal degenerative diseases (RDDs). Whereas some therapies exist for early stages of RDDs, no effective treatment is currently available for later stages, and once photoreceptors are lost, the only option to rescue vision is cell transplantation. With the use of the Royal College of Surgeons (RCS) rat model of retinal degeneration, we sought to determine whether combined transplantation of human-induced pluripotent stem cell (hiPSC)-derived retinal precursor cells (RPCs) and retinal pigment epithelial (RPE) cells was superior to RPE or RPC transplantation alone in preserving retinal from degeneration. hiPSC-derived RPCs and RPE cells expressing (GFP) were transplanted into the subretinal space of rats. In vivo monitoring showed that grafted cells survived 12 weeks in the subretinal space, and rats treated with RPE + RPC therapy exhibited better conservation of the outer nuclear layer (ONL) and visual response than RPE-treated or RPC-treated rats. Transplanted RPE cells integrated in the host RPE layer, whereas RPC mostly remained in the subretinal space, although a limited number of cells integrated in the ONL. In conclusion, the combined transplantation of hiPSC-derived RPE and RPCs is a potentially superior therapeutic approach to protect retina from degeneration in RDDs.

IPS cell transplantation in a mouse model – A semiquantitative assessment

This study was carried out to determine the effectiveness of induced pluripotent stem (iPS) cell-transplantation as a therapy on wound healing using a splinted wound mouse model. Eighteen clinically healthy female mice were treated with 1μg/g of dexamethasone intramuscular injection once a day for three consecutive days to induce immunosuppression. Under anaesthesia, two sterile wounds were made on shaved backs of each mouse via biopsy punch. With a gap of 20 mm in-between, six injections were delivered once, around the two wounds before the wounds were adhered with splints and wound dressing. The mice were divided into two groups; Group A was given 7 × 10 5 iPS cells in each injection, and while Group B were injected with 0.9% sodium chloride instead. Wound closure rates were determined through timed scaled photography and analyses with GNU Image Manipulation Program. Three mice from each group were euthanised every 7 days post-wounding, immediately after which wound beds and blood were harvested. Wound beds were fixed, processed, blocked, and sectioned. Sections were stained with HE Masson’s Trichrome; and immunolabeled for CD31 and CD68; and then examined under a compound microscope subjected to a scoring scheme. From this semiquantitative assessment, Group A sections scored better in angiogenesis on day 7 (p = 0.057), a vital process in the proliferation stage, and hypodermis regeneration on day 21 (p = 0.006), which suggests the wound healing is complete. Together, these findings suggest Group A was ahead in the process of wound healing; although results from lymphocyte count, fibroblast count, granulation tissue, collagen, and wound closure were not statistically significant.

Grafted human induced pluripotent stem cells improve the outcome of spinal cord injury: modulation of the lesion microenvironment

Spinal cord injury results in irreversible tissue damage followed by a very limited recovery of function. In this study we investigated whether transplantation of undifferentiated human induced pluripotent stem cells (hiPSCs) into the injured rat spinal cord is able to induce morphological and functional improvement. hiPSCs were grafted intraspinally or intravenously one week after a thoracic (T11) spinal cord contusion injury performed in Fischer 344 rats. Grafted animals showed significantly better functional recovery than the control rats which received only contusion injury. Morphologically, the contusion cavity was significantly smaller, and the amount of spared tissue was significantly greater in grafted animals than in controls. Retrograde tracing studies showed a statistically significant increase in the number of FB-labeled neurons in different segments of the spinal cord, the brainstem and the sensorimotor cortex. The extent of functional improvement was inversely related to the amount of chondroitin-sulphate around the cavity and the astrocytic and microglial reactions in the injured segment. The grafts produced GDNF, IL-10 and MIP1-alpha for at least one week. These data suggest that grafted undifferentiated hiPSCs are able to induce morphological and functional recovery after spinal cord contusion injury.

Abstract 14554: Angiogenic Agent Ono-1301 Enhanced Cardiac Contractile Proteins in Hipsc Derived Cardiac Tissue-like Construct With Functional Angiogenesis

Introduction: Transplantation of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) into myocardial infarcted areas has shown potential in healing myocardial infarction (MI). However, the survival rate of transplanted cells is yet considered limited, restricting the therapeutic effects of the transplantation. We assumed that adding angiogenic agent ONO-1301 could promote early stage angiogenesis between host and graft, and benefit the therapeutic effects of hiPSC-CM transplantation. Methods: This study is based on our former study of Cardiac Tissue-Like Construct (CTLC), where 5 x10e6 of hiPSC-CM was seeded on a 1x1cm poly(lactic-co-glycolic acid) (PLGA) nano fiber (Figure A). In addition, angiogenic agent ONO-1301 was mixed into the fibers. After 24h culture in vitro, 3 layers of CTLCs were transplanted into Nude rat MI models with or without ONO-1301. The rats were raised for another 4 or 8 weeks before sacrifice. Results: In vitro experiments have shown that supernatant of iPS-CM with ONO-1301 underwent a rise in VEGF during a 3 to 6 day culture (Figure B). The VEGF concentration in ONO-1301 positive group is much higer than ONO-1301 negative group (P=0.022) on day3. This difference narrows down over time. In vivo experiments on nude rat have shown that capillary density on MI border zone of ONO fiber+iPS-CM group is 29.95% higher than that of PLGA fiber+iPS-CM group (P=0.004) (figure C). HE and immunofluorescence staining shows remaining transplanted hiPSC-CMs in ONO fiber+iPS-CM group shows more significant TNT2 and human nuclear antigen(HNA) expression than that of PLGA fiber+iPS-CM group (Figure D and E). Also ONO fiber+iPS-CM group showed functional recovery compared to the sham.

Trophoblast Stem-Cell-Derived Exosomes Improve Doxorubicin-Induced Dilated Cardiomyopathy by Modulating the let-7i/YAP Pathway

Trophoblast stem cells (TSCs) have been confirmed to play a cardioprotective role in heart failure. However, whether TSC-derived exosomes (TSC-exos) can protect against cardiac injury remains unclear. In the present study, TSC-exos were isolated from the supernatant of TSCs using the ultracentrifugation method and characterized by transmission electron microscopy and western blotting. Utilizing the public Gene Expression Omnibus (GEO) database, we found that let-7i and Yes-associated protein 1 (YAP) could participate in the development of heart failure. In vitro, AC16 cardiomyocytes subjected to doxorubicin (DOX) were treated with TSC-exos or let-7i mimic. Flow cytometry showed that TSC-exos and let-7i both decreased cardiomyocyte apoptosis. In vivo, mice that were intraperitoneally injected into DOX received either PBS, TSC-exos, or AAV9-let7iup for let-7i overexpression. Mice receiving TSC-exos and AAV9-let7iup showed improved cardiac function and decreased inflammatory responses, accompanied by downregulated YAP signaling. Mechanistically, TSC-exos could transfer let-7i to cardiomyocytes and silence the YAP signaling pathway. In conclusion, TSC-exos could alleviate DOX-induced cardiac injury via the let-7i/YAP pathway, which sheds new light on the application of TSC-exos as a potential therapeutic tool for heart failure.

Host sex and transplanted human induced pluripotent stem cell phenotype interact to influence sensorimotor recovery in a mouse model of cortical contusion injury

Traumatic brain injury (TBI) is a substantial cause of disability and death worldwide. Primary head trauma triggers chronic secondary injury mechanisms in the brain that are a focus of therapeutic efforts to treat TBI. Currently, there is no successful clinical strategy to repair brain injury. Cell transplantation therapies have demonstrated promise in attenuating secondary injury mechanisms of neuronal death and dysfunction in animal models of brain injury. In this study, we used a unilateral cortical contusion injury (CCI) model of sensorimotor brain injury to examine the effects of human induced pluripotent stem cell (hiPSC) transplantation on pathology in male and female adult mice. We determined transplanted hiPSC-derived neural stem cells (NSCs) and neuroblasts but not astrocytes best tolerate the injured host environment. Surviving NSC and neuroblast cells were clustered at the site of injection within the deep layers of the cortex and underlying corpus callosum. Cell grafts extended neuritic processes that crossed the midline into the contralateral corpus callosum or continued laterally within the external capsule to enter the ipsilateral entorhinal cortex. To determine the effect of transplantation on neuropathology, we performed sensorimotor behavior testing and stereological estimation of host neurons, astrocytes, and microglia within the contused cortex. These measures did not reveal a consistent effect of transplantation on recovery post-injury. Rather the positive and negative effects of cell transplantation were dependent on the host sex, highlighting the importance of developing patient-specific approaches to treat TBI. Our study underscores the complex interactions of sex, neuroimmune responses and cell therapy in a common experimental model of TBI.

Global trends in clinical trials involving pluripotent stem cells: a systematic multi-database analysis

Pluripotent stem cells (PSCs) hold great potential for novel therapeutic approaches to regenerate or replace functionally impaired tissues. Since the introduction of the induced pluripotent stem cell technology in 2006, the number of scientific publications on this topic has constantly been increasing. However, so far no therapy based on PSCs has found its way into routine clinical use. In this study, we examined research trends related to clinical trials involving PSCs based on data obtained from ClinicalTrials.gov, the ICTRP database from the World Health Organization, as well as from a search of all individual databases that are included in the ICTRP using a multistep search algorithm. Following a stringent inclusion/exclusion procedure 131 studies remained that could be classified as clinical trials involving PSCs. The magnitude of these studies (77.1%) was observational, which implies that no cells were transplanted into patients, and only a minority of studies (22.9%) were of an interventional study type. The number of clinical trials involving induced pluripotent stem cells (iPSCs, 74.8%) was substantially higher than the one involving embryonic stem cells (ESCs, 25.2%). However, the picture changes completely when focusing on interventional studies, where in the majority (73.3%) of cases ESCs were used. Interestingly, also the study duration was significantly shorter for interventional versus observational trials (p = 0.002). When focusing on the geographical study regions, it became obvious that the greatest part of all observational trials was performed in the USA (41.6%) and in France (16.8%), while the magnitude of interventional studies was performed in Asian countries (China 36.7%, Japan 13.3%, South Korea 10.0%) and in the field of ophthalmology. In summary, these results indicate that only a limited number of trials were focusing on the actual transplantation of PSCs into patients in a rather narrow field of diagnoses. The future will tell us, if the iPSC technology will ultimately overcome the current challenges and will finally make its way into routine clinical use.

Generation of Human Renal Vesicles in Mouse Organ Niche Using Nephron Progenitor Cell Replacement System

Animal fetuses may be used for the regeneration of human organs. We have previously generated a transgenic mouse model that allows diphtheria toxin (DT)-induced ablation of Six2-positive nephron progenitor cells (NPCs). Elimination of existing native host NPCs enables their replacement with donor NPCs, which can generate neo-nephrons. However, this system cannot be applied to human NPCs, because DT induces apoptosis in human cells. Therefore, the present study presents a transgenic mouse model for the ablation of NPCs using tamoxifen, which does not affect human cells. Using this system, we successfully regenerate interspecies neo-nephrons, which exhibit urine-producing abilities, from transplanted rat NPCs in a mouse host. Transplantation of human induced pluripotent stem cell (iPSC)-derived NPCs results in differentiation into renal vesicles, which connect to the ureteric bud of the host. Thus, we demonstrate thepossibility of the regeneration of human kidneys derived from human iPSC-derived NPCs via NPC replacement.

Application of Magnetic Resonance Imaging Molecular Probe in the Study of Pluripotent Stem Cell–Derived Neural Stem Cells for the Treatment of Posttraumatic Paralysis of Cerebral Infarction

The feasibility and efficacy of magnetic resonance imaging molecular probe application and pluripotent stem cell-derived neural stem cell (NSC) transplantation for the treatment of hind limb paralysis in mice with cerebral infarction were studied. A model of middle cerebral artery infarction using adult mice was established to stimulate hind limb reactions. After the model was successfully established, the mice were first divided into an experimental group and a control group, with 25 mice in each group. Cultured neural cells were obtained from the cerebral cortex and hippocampus of a mouse 15 days pregnant to prepare pluripotent stem cells. Pluripotent stem cell-derived NSCs were identified by positive expression of Nestin. The experimental group was injected with 1 μL of NSC suspension through the tail vein, and the control group was injected with 1 μL of saline through the tail vein. The neurologic function of mice in each group was scored 1 day, 3 days, 7 days, 14 days, and 28 days after transplantation according to the Garcia 18 subscale. Finally, the differentiation, migration, and integration of pluripotent stem cell-derived NSCs after transplantation were observed using a magnetic resonance imaging molecular probe method. The results showed that the neurologic function scores of the ischemic transplantation group were significantly higher than those of the control group, and the results were significantly different (P < 0.05). Through research, it was found that after transplantation of pluripotent stem cell-derived NSCs, the transplanted cells migrated and differentiated around the body at 28 days and participated in angiogenesis, and the blood vessels in the infarcted area were obviously proliferated. The NSCs cultured invitro were transplanted to the small infarction after cerebral infarction. In rats, it plays a positive role in the repair of nerve function in mice with cerebral infarction. NSCs cultured invitro can survive, migrate, and differentiate in the brain tissue of mouse ischemic models and play a positive role in the repair of neurologic function in mice with cerebral infarction. Magnetic resonance imaging molecular probes have a good adjuvant effect on the use of pluripotent stem cell-derived NSCs to treat hind limb paralysis in mice with cerebral infarction.

Investigation of Clinical Safety of Human iPS Cell-Derived Liver Organoid Transplantation to Infantile Patients in Porcine Model

Transplantation of liver organoids has been investigated as a treatment alternative to liver transplantation for chronic liver disease. Transportal approach can be considered as a method of delivering organoids to the liver. It is important to set the allowable organoid amount and verify translocation by intraportal transplantation. We first examined the transplantation tolerance and translocation of porcine fetal liver-derived allogeneic organoids using piglets. Fetal liver-derived organoids generated from the Kusabira Orange-transduced pig were transplanted to the 10-day-old piglet liver through the left branch of the portal vein. All recipients survived without any observable adverse events. In contrast, both local and main portal pressures increased transiently during transplantation. In necropsy samples, Kusabira Orange-positive donor cells were detected primarily in the target lobe of the liver and partly in other areas, including the lungs and brain. As we confirmed the transplantation allowance by porcine fetal liver-derived organoids, we performed intraportal transplantation of human-induced pluripotent stem cell (iPSC)-derived liver organoid, which we plan to use in clinical trials, and portal pressure and translocation were investigated. Human iPSC-derived liver organoids were transplanted into the same 10-day-old piglet. Portal hypertension and translocation of human iPSC-derived liver organoids to the lungs were observed in one of two transplanted animals. Translocation occurred in the piglet in which patent ductus venosus (PDV) was observed. Therefore, a 28-day-old piglet capable of surgically ligating PDV was used, and after the PDV was ligated, human iPSC-derived liver organoids with the amount of which is scheduled in clinical trials were transplanted. This procedure inhibited the translocation of human iPSC-derived liver organoids to extrahepatic sites without no portal hypertension. In conclusion, human iPSC-derived liver organoids can be safely transplanted through the portal vein. Ligation of the ductus venosus prior to transplantation was effective in inhibiting extrahepatic translocation in newborns and infants.

Tissue inhibitor of metalloproteinase proteins inhibit teratoma growth in mice transplanted with pluripotent stem cells.

Pluripotent stem cells (PSCs) can serve as an unlimited cell source for transplantation therapies for treating various devastating diseases, such as cardiovascular diseases, diabetes, and Parkinson's disease. However, PSC transplantation has some associated risks, including teratoma formation from the remaining undifferentiated PSCs. Thus, for successful clinical application, it is essential to ablate the proliferative PSCs before or after transplantation. In this study, neural stem cell-derived conditioned medium (NSC-CM) inhibited the proliferation of PSCs and PSC-derived neural precursor (NP) cells without influencing the potential of PSC-NP cells to differentiate into neurons in vitro and prevented teratoma growth in vivo. Moreover, we found that the NSC-CM remarkably decreased the expression levels of Oct4 and cyclin D1 that Oct4 directly binds to and increased the cleaved-caspase 3-positive cell death through the DNA damage response in PSCs and PSC-NPs. Interestingly, we found that NSCs distinctly secreted the tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 proteins. These proteins suppressed not only the proliferation of PSCs in cell culture but also teratoma growth in mice transplanted with PSCs through inhibition of matrix metalloproteinase (MMP)-2 and MMP-9 activity. Taken together, these results suggest that the TIMP proteins may improve the efficacy and safety of the PSC-based transplantation therapy.

CRISPR/Cas9 gene correction of HbH-CS thalassemia-induced pluripotent stem cells

Haemoglobin (Hb) H-constant spring (CS) alpha thalassaemia (- -/-αCS) is the most common type of nondeletional Hb H disease in southern China. The CRISPR/Cas9-based gene correction of patient-specific induced pluripotent stem cells (iPSCs) and cell transplantation now represent a therapeutic solution for this genetic disease. We designed primers for the target sites using CRISPR/Cas9 to specifically edit the HBA2 gene with an Hb-CS mutation. After applying a correction-specific PCR assay to purify the corrected clones followed by sequencing to confirm the mutation correction, we verified that the purified clones retained full pluripotency and exhibited a normal karyotype. This strategy may be promising in the future, although it is far from representing a solution for the treatment of HbH-CS thalassemia now.

Human NPCs can degrade α–syn fibrils and transfer them preferentially in a cell contact-dependent manner possibly through TNT-like structures

Parkinson's disease (PD) is the second most common neurodegenerative disorder whereby loss of midbrain dopaminergic neurons results in motor dysfunction. Transplantation of human induced pluripotent stem cells (iPSCs) into the brain of patients affected by PD is one of the therapeutic approaches that has gained interest to compensate for the degeneration of neurons and improve disease symptoms. However, only a part of transplanted cells can differentiate into mature neurons while the majority remains in undifferentiated state. Here we investigated whether human neuronal precursor cells (hNPCs) derived from iPSCs have an active role in α-synuclein (α-syn) pathology. Our findings demonstrate that α-syn fibrils are taken up by hNPCs and are preferentially localized in lysosomes where they can be degraded. However, α-syn fibrils are also transferred between hNPCs in a cell-to-cell contact dependent manner, and are found in tunneling nanotube (TNT)-like structures. Thus, NPCs can have a dual role in the progression of α-syn pathology, which should be considered in human transplants.

Expansion Culture of Human Pluripotent Stem Cells and Production of Cardiomyocytes.

Transplantation of human pluripotent stem cell (hPSCs)-derived cardiomyocytes for the treatment of heart failure is a promising therapy. In order to implement this therapy requiring numerous cardiomyocytes, substantial production of hPSCs followed by cardiac differentiation seems practical. Conventional methods of culturing hPSCs involve using a 2D culture monolayer that hinders the expansion of hPSCs, thereby limiting their productivity. Advanced culture of hPSCs in 3D aggregates in the suspension overcomes the limitations of 2D culture and attracts immense attention. Although the hPSC production needs to be suitable for subsequent cardiac differentiation, many studies have independently focused on either expansion of hPSCs or cardiac differentiation protocols. In this review, we summarize the recent approaches to expand hPSCs in combination with cardiomyocyte differentiation. A comparison of various suspension culture methods and future prospects for dynamic culture of hPSCs are discussed in this study. Understanding hPSC characteristics in different models of dynamic culture helps to produce numerous cells that are useful for further clinical applications.

Potent immunomodulation and angiogenic effects of mesenchymal stem cells versus cardiomyocytes derived from pluripotent stem cells for treatment of heart failure

BackgroundOptimal cell type as cell-based therapies for heart failure (HF) remains unclear. We sought to compare the safety and efficacy of direct intramyocardial transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs) in a porcine model of HF.MethodsEight weeks after induction of HF with myocardial infarction (MI) and rapid pacing, animals with impaired left ventricular ejection fraction (LVEF) were randomly assigned to receive direct intramyocardial injection of saline (MI group), 2 × 108 hESC-CMs (hESC-CM group), or 2 × 108 hiPSC-MSCs (hiPSC-MSC group). The hearts were harvested for immunohistochemical evaluation after serial echocardiography and hemodynamic evaluation and ventricular tachyarrhythmia (VT) induction by in vivo programmed electrical stimulation.ResultsAt 8 weeks post-transplantation, LVEF, left ventricular maximal positive pressure derivative, and end systolic pressure-volume relationship were significantly higher in the hiPSC-MSC group but not in the hESC-CM group compared with the MI group. The incidence of early spontaneous ventricular tachyarrhythmia (VT) episodes was higher in the hESC-CM group but the incidence of inducible VT was similar among the different groups. Histological examination showed no tumor formation but hiPSC-MSCs exhibited a stronger survival capacity by activating regulatory T cells and reducing the inflammatory cells. In vitro study showed that hiPSC-MSCs were insensitive to pro-inflammatory interferon-gamma-induced human leukocyte antigen class II expression compared with hESC-CMs. Moreover, hiPSC-MSCs also significantly enhanced angiogenesis compared with other groups via increasing expression of distinct angiogenic factors.ConclusionsOur results demonstrate that transplantation of hiPSC-MSCs is safe and does not increase proarrhythmia or tumor formation and superior to hESC-CMs for the improvement of cardiac function in HF. This is due to their immunomodulation that improves in vivo survival and enhanced angiogenesis via paracrine effects.

Immature electrophysiological properties of human-induced pluripotent stem cell-derived neurons transplanted into the mouse cortex for 7 weeks.

The transplantation of human-induced pluripotent stem cell (hiPSC)-derived cells has emerged as a potential clinical approach for the treatment of brain diseases. Recent studies with animal disease models have shown that hiPSC-derived neurons transplanted into the brain, especially the nigrostriatal area, could restore degenerated brain functions. Further works are required to test whether hiPSC-derived neurons can also gain functional properties for other cortical areas. In this study, hiPSC-derived neurospheres were transplanted into the adult mouse hippocampus and sensory cortex. Most transplanted hiPSC-derived neurons expressed both Nestin and NeuN at 7 weeks after transplantation. Whole-cell patch-clamp recordings from brain slices indicated that transplanted cells showed no action potentials upon current injection and few small inward currents, indicating that hiPSC-derived neurons did not become functionally mature within these time periods.