Human Pluripotent Stem Cell-Derived Skeletal Muscle Organoid Model of Aging-Induced Sarcopenia.

Background: Sarcopenia is defined by the age-related loss of muscle mass and function, with an impaired regenerative capacity of satellite cells (SCs). Despite their recognized importance in muscle regeneration, human model-based studies on SCs in sarcopenia are still lacking, limiting our understanding of their role in age-related muscle loss. Here, we aimed to develop a sarcopenia model using human pluripotent stem cells (hPSCs)-derived skeletal muscle organoids (hSkMOs) and prevent the sarcopenia progression by testosterone treatment.

Human embryonic stem cell-derived Sertoli cells as an immune modulator of cell transplantation therapy in a diabetic mice model.

Objective: Sertoli cells (SCs) are somatic cells that are a part of the seminiferous tubules in the testes and support germ cell development and maturation. Additionally, SCs play another role in protecting male germ cells from immune destruction via the formation of the blood-testis barrier and the secretion of several immunoregulatory factors. Based on these characteristics, SCs have been suggested to create a tolerogenic environment to protect co-transplanted cells as immune modulators.

Ovarian Function Restoration with Biomimetic Scaffold Incorporating Angiogenic Molecules and Antioxidant in Chemotherapy-Induced Perimenopausal Model.

Chemotherapy-induced premature ovarian insufficiency (POI) is a major cause of infertility and hormonal imbalance in young female cancer survivors. In this study, developed a biomimetic scaffold is developed that incorporates polydeoxyribonucleotide (PDRN) and melatonin to restore ovarian function. The scaffold is designed to mimic the ovarian extracellular matrix (ECM), enhancing angiogenesis, promoting antioxidant effects, and reducing reactive oxygen species (ROS).

Preservation of ovarian function using human pluripotent stem cell-derived mesenchymal progenitor cells.

Ovarian reserve diminishes with age, and older women experience a corresponding shift in sex hormone levels. These changes contribute to an age-dependent decrease in fertility and a decline in overall health. Furthermore, while survival rates following cancer treatment have improved for young female patients, a reduction in ovarian function due to the side effects of such treatments can be difficult to avoid.

Kidney tissue regeneration using bioactive scaffolds incorporated with differentiating extracellular vesicles and intermediate mesoderm cells.

Background: To overcome the limitations of current alternative therapies for chronic kidney disease (CKD), tissue engineering-mediated regeneration strategies have demonstrated the possibilities for complete kidney tissue regeneration. Given the challenges associated with the reproducibility of renal basal cells, the incorporation of intermediate mesoderm (IM) cells and bioactive materials to control bioactivities of cells with supported scaffolds should be considered as a viable approach to enable the regeneration of the complex kidney structure via renal differentiation.

Methods: We developed PMEZ scaffolds by combining crucial bioactive components, such as ricinoleic acid-grafted Mg(OH) (M), extracellular matrix (E), and alpha lipoic acid-conjugated ZnO (Z) integrated into biodegradable porous PLGA (P) platform.

Expression of Major Histocompatibility Complex during Neuronal Differentiation of Somatic Cell Nuclear Transfer-Human Embryonic Stem Cells.

Human pluripotent stem cells (hPSCs) such as human embryonic stem cells (hESCs), induced pluripotent stem cells, and somatic cell nuclear transfer (SCNT)-hESCs can permanently self-renew while maintaining their capacity to differentiate into any type of somatic cells, thereby serving as an important cell source for cell therapy. However, there are persistent challenges in the application of hPSCs in clinical trials, where one of the most significant is graft rejection by the patient immune system in response to human leukocyte antigen (HLA) mismatch when transplants are obtained from an allogeneic (non-self) cell source. Homozygous SCNT-hESCs (homo-SCNT-hESCs) were used to simplify the clinical application and to reduce HLA mismatch.

Use of lysates from pooled human mononuclear cells to activate CD3 T cells in humanized mice with low human cell engraftment efficiency.

In regenerative medicine, humanized mice (hu-mice) are extremely valuable for verifying the cross talk between immune cells and therapeutic cells. Given the highly dynamic nature of the activities of immune cells, the in vitro platform does not allow for screening of their exact interactions with different therapeutic cells. By contrast, hu-mice have been widely applied for in vivo studies, especially those on immune rejection.

Generation of Skeletal Muscle Organoids from Human Pluripotent Stem Cells to Model Myogenesis and Muscle Regeneration.

In vitro organoids derived from human pluripotent stem cells (hPSCs) have been developed as essential tools to study the underlying mechanisms of human development and diseases owing to their structural and physiological similarity to corresponding organs. Despite recent advances, there are a few methodologies for three-dimensional (3D) skeletal muscle differentiation, which focus on the terminal differentiation into myofibers and investigate the potential of modeling neuromuscular disorders and muscular dystrophies. However, these methodologies cannot recapitulate the developmental processes and lack regenerative capacity.

Changes in Methylation Patterns of Tumor Suppressor Genes during Extended Human Embryonic Stem Cell Cultures.

While studies on embryonic stem cells have been actively conducted, little is known about the epigenetic mechanisms in human embryonic stem cells (hESCs) in extended culture systems. Here, we investigated whether CpG island (CGI) methylation patterns of 24 tumor suppressor genes could be maintained during extended hESC cultures. In total, 10 hESC lines were analyzed.

Rapid Production and Genetic Stability of Human Mesenchymal Progenitor Cells Derived from Human Somatic Cell Nuclear Transfer-Derived Pluripotent Stem Cells.

Pluripotent stem cell-derived mesenchymal progenitor cells (PSC-MPCs) are primarily derived through two main methods: three-dimensional (3D) embryoid body-platform (EB formation) and the 2D direct differentiation method. We recently established somatic cell nuclear transfer (SCNT)-PSC lines and showed their stemness. In the present study, we produced SCNT-PSC-MPCs using a novel direct differentiation method, and the characteristics, gene expression, and genetic stability of these MPCs were compared with those derived through EB formation.

Identification of Putative Markers That Predict the In Vitro Senescence of Mesenchymal Progenitor Cells.

Mesenchymal progenitor cells (MPCs) are a promising cell source for regenerative medicine because of their immunomodulatory properties, anti-inflammatory molecule secretion, and replacement of damaged cells. Despite these advantages, heterogeneity in functional potential and limited proliferation capacity of MPCs, as well as the lack of suitable markers for product potency, hamper the development of large-scale manufacturing processes of MPCs. Therefore, there is a sustained need to develop highly proliferative and standardized MPCs in vitro and find suitable functional markers for measuring product potency.

Recovery of ovarian function by human embryonic stem cell-derived mesenchymal stem cells in cisplatin-induced premature ovarian failure in mice.

Background: Clinical use of mesenchymal stem cells (MSCs) requires a uniform cell population, and their harvesting is invasive and produces a limited number of cells. Human embryonic stem cell-derived MSCs (hESC-MSCs) can differentiate into three germ layers and possess immunosuppressive effects in vitro. Anticancer treatment is a well-known risk factor for premature ovarian failure (POF).

Cryopreserved Human Oocytes and Cord Blood Cells Can Produce Somatic Cell Nuclear Transfer-Derived Pluripotent Stem Cells with a Homozygous HLA Type.

Human pluripotent stem cells (PSCs) through somatic cell nuclear transfer (SCNT) may be an important source for regenerative medicine. The low derivation efficiency of stem cells and the accessibility of human oocytes are the main obstacles to their application. We previously reported that the efficiency of SCNT was increased by overexpression of H3K9me3 demethylase.

Single cell-derived clonally expanded mesenchymal progenitor cells from somatic cell nuclear transfer-derived pluripotent stem cells ameliorate the endometrial function in the uterus of a murine model with Asherman's syndrome.

Objectives: Because primary mesenchymal progenitor cells (adult-MPCs) have various functions that depend on the tissue origin and donor, de novo MPCs from human pluripotent stem cells (hPSCs) would be required in regenerative medicine. However, the characteristics and function of MPCs derived from reprogrammed hPSCs have not been well studied. Thus, we show that functional MPCs can be successfully established from a single cell-derived clonal expansion following MPC derivation from somatic cell nuclear transfer-derived (SCNT)-hPSCs, and these cells can serve as therapeutic contributors in an animal model of Asherman's syndrome (AS).

Anti-apoptotic Regulation Contributes to the Successful Nuclear Reprogramming Using Cryopreserved Oocytes.

Cryopreservation has a negative effect on the quality of oocytes and may be closely associated with increased levels of reactive oxygen species (ROS) and apoptotic events. The purpose of the present study was to evaluate the detrimental effects on the developmental competence of somatic cell nuclear transferred (SCNT) mouse embryos using vitrified (cryopreserved) oocytes and to evaluate the recovery effects of melatonin on cryo-damage in cloned embryos. Development of SCNT embryos using cryopreserved oocyte cytoplasm (SCNT-CROC) was inferior to those using fresh cytoplasm (SCNT-FOC).

Characterization of Tetraploid Somatic Cell Nuclear Transfer-Derived Human Embryonic Stem Cells.

Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues.

RuvB-Like Protein 2 (Ruvbl2) Has a Role in Directing the Neuroectodermal Differentiation of Mouse Embryonic Stem Cells.

Although many factors have been identified to be involved in the development of the neuroectoderm during embryogenesis, it is still important to identify novel factors that convert undifferentiated embryonic cells into neuroectoderm. RuvB-like protein 2 (Ruvbl2) is known to regulate gene expression via chromatin remodeling by participating in multi-protein complexes, but its role during embryonic development is not well known. In this study, we established Ruvbl2-overexpressing mouse embryonic stem cells and examined their capacity to specifically differentiate into neuroectoderm and confirmed the specific expression of RUVBL2 in early embryonic neuroectoderm.

An efficient SCNT technology for the establishment of personalized and public human pluripotent stem cell banks.

Although three different research groups have reported successful derivations of human somatic cell nuclear transfer-derived embryonic stem cell (SCNT-ESC) lines using fetal, neonatal and adult fibroblasts, the extremely poor development of cloned embryos has hindered its potential applications in regenerative medicine. Recently, however, our group discovered that the severe methylation of lysine 9 in Histone H3 in a human somatic cell genome was a major SCNT reprogramming barrier, and the overexpression of KDM4A, a H3K9me3 demethylase, significantly improved the blastocyst formation of SCNT embryos. In particular, by applying this new approach, we were able to produce multiple SCNT-ES cell lines using oocytes obtained from donors whose eggs previously failed to develop to the blastocyst stage.

An integrated systems biology approach identifies positive cofactor 4 as a factor that increases reprogramming efficiency.

Spermatogonial stem cells (SSCs) can spontaneously dedifferentiate into embryonic stem cell (ESC)-like cells, which are designated as multipotent SSCs (mSSCs), without ectopic expression of reprogramming factors. Interestingly, SSCs express key pluripotency genes such as Oct4, Sox2, Klf4 and Myc. Therefore, molecular dissection of mSSC reprogramming may provide clues about novel endogenous reprogramming or pluripotency regulatory factors.

Histone Demethylase Expression Enhances Human Somatic Cell Nuclear Transfer Efficiency and Promotes Derivation of Pluripotent Stem Cells.

The extremely low efficiency of human embryonic stem cell (hESC) derivation using somatic cell nuclear transfer (SCNT) limits its potential application. Blastocyst formation from human SCNT embryos occurs at a low rate and with only some oocyte donors. We previously showed in mice that reduction of histone H3 lysine 9 trimethylation (H3K9me3) through ectopic expression of the H3K9me3 demethylase Kdm4d greatly improves SCNT embryo development.

Human somatic cell nuclear transfer using adult cells.

Derivation of patient-specific human pluripotent stem cells via somatic cell nuclear transfer (SCNT) has the potential for applications in a range of therapeutic contexts. However, successful SCNT with human cells has proved challenging to achieve, and thus far has only been reported with fetal or infant somatic cells. In this study, we describe the application of a recently developed methodology for the generation of human ESCs via SCNT using dermal fibroblasts from 35- and 75-year-old males.