Human induced pluripotent stem cells for monogenic disease modelling and therapy

Recent and advanced protocols are now available to derive human induced pluripotent stem cells (hiPSCs) from patients affected by genetic diseases. No curative treatments are available for many of these diseases; thus, hiPSCs represent a major impact on patient’ health. hiPSCs represent a valid model for the in vitro study of monogenic diseases, together with a better comprehension of the pathogenic mechanisms of the pathology, for both cell and gene therapy protocol applications. Moreover, these pluripotent cells represent a good opportunity to test innovative pharmacological treatments focused on evaluating the efficacy and toxicity of novel drugs. Today, innovative gene therapy protocols, especially gene editing-based, are being developed, allowing the use of these cells not only as in vitro disease models but also as an unlimited source of cells useful for tissue regeneration and regenerative medicine, eluding ethical and immune rejection problems. In this review, we will provide an up-to-date of modelling monogenic disease by using hiPSCs and the ultimate applications of these in vitro models for cell therapy. We consider and summarize some peculiar aspects such as the type of parental cells used for reprogramming, the methods currently used to induce the transcription of the reprogramming factors, and the type of iPSC-derived differentiated cells, relating them to the genetic basis of diseases and to their inheritance model.

Induced pluripotent stem cells for modeling neurological disorders

Several diseases have been successfully modeled since the development of induced pluripotent stem cell(i PSC) technology in 2006. Since then, methods for increased reprogramming efficiency and cell culture maintenance have been optimized and many protocols for differentiating stem cell lines have been successfully developed, allowing the generation of several cellular subtypes in vitro. Gene editing technologies have also greatly advanced lately, enhancing disease-specific phenotypes by creating isogenic cell lines, allowing mutations to be corrected in affected samples or inserted in control lines. Neurological disorders have benefited the most from i PSC-disease modeling for its capability for generating disease-relevant cell types in vitro from the central nervous system, such as neurons and glial cells, otherwise only available from post-mortem samples. Patient-specific i PSC-derived neural cells can recapitulate the phenotypes of these diseases and therefore, considerably enrich our understanding of pathogenesis, disease mechanism and facilitate the development of drug screening platforms for novel therapeutic targets. Here, we review the accomplishments and the current progress in human neurological disorders by using i PSC modeling for Alzheimer's disease, Parkinson's disease, Huntington's disease, spinal muscular atrophy, amyotrophic lateral sclerosis, duchenne muscular dystrophy, schizophrenia and autism spectrum disorders, which include Timothy syndrome, Fragile X syndrome, Angelman syndrome, Prader-Willi syndrome, PhelanMc Dermid, Rett syndrome as well as Nonsyndromic Autism.

Non-human primate pluripotent stem cells for the preclinical testing of regenerative therapies

Non-human primates play a key role in the preclinical validation of pluripotent stem cell-based cell replacement therapies.Pluripotent stem cells used as advanced therapy medical products boost the possibility to regenerate tissues and organs affected by degenerative diseases.Therefore,the methods to derive human induced pluripotent stem cell and embryonic stem cell lines following clinical standards have quickly developed in the last 15 years.For the preclinical validation of cell replacement therapies in non-human primates,it is necessary to generate non-human primate pluripotent stem cell with a homologous quality to their human counterparts.However,pluripotent stem cell technologies have developed at a slower pace in non-human primates in comparison with human cell systems.In recent years,however,relevant progress has also been made with non-human primate pluripotent stem cells.This review provides a systematic overview of the progress and remaining challenges for the generation of non-human primate induced pluripotent stem cells/embryonic stem cells for the preclinical testing and validation of cell replacement therapies.We focus on the critical domains of(1)reprogramming and embryonic stem cell line derivation,(2)cell line maintenance and characterization and,(3)application of non-human primate pluripotent stem cells in the context of selected preclinical studies to treat cardiovascular and neurodegenerative disorders performed in non-human primates.

Human induced pluripotent stem cell-derived therapies for regeneration after central nervous system injury

In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained intriguing.Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as neurons.While embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns remained.These barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem cells.The advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal subpopulations.The precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed differentiation.While the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma formation.Cells of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of success.Although the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor cells.Furthermore,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration.Lastly,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression.Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes.This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration.

Induced pluripotent stem cell-related approaches to generate dopaminergic neurons for Parkinson's disease

The progressive loss of dopaminergic neurons in affected patient brains is one of the pathological features of Parkinson's disease,the second most common human neurodegenerative disease.Although the detailed pathogenesis accounting for dopaminergic neuron degeneration in Parkinson's disease is still unclear,the advancement of stem cell approaches has shown promise for Parkinson's disease research and therapy.The induced pluripotent stem cells have been commonly used to generate dopaminergic neurons,which has provided valuable insights to improve our understanding of Parkinson's disease pathogenesis and contributed to anti-Parkinson's disease therapies.The current review discusses the practical approaches and potential applications of induced pluripotent stem cell techniques for generating and differentiating dopaminergic neurons from induced pluripotent stem cells.The benefits of induced pluripotent stem cell-based research are highlighted.Various dopaminergic neuron differentiation protocols from induced pluripotent stem cells are compared.The emerging three-dimension-based brain organoid models compared with conventional two-dimensional cell culture are evaluated.Finally,limitations,challenges,and future directions of induced pluripotent stem cell–based approaches are analyzed and proposed,which will be significant to the future application of induced pluripotent stem cell-related techniques for Parkinson's disease.

Modulation of the Nogo signaling pathway to overcome amyloid-β-mediated neurite inhibition in human pluripotent stem cell-derived neurites

Neuronal cell death and the loss of connectivity are two of the primary pathological mechanisms underlying Alzheimer's disease.The accumulation of amyloid-βpeptides,a key hallmark of Alzheimer's disease,is believed to induce neuritic abnormalities,including reduced growth,extension,and abnormal growth cone morphology,all of which contribute to decreased connectivity.However,the precise cellular and molecular mechanisms governing this response remain unknown.In this study,we used an innovative approach to demonstrate the effect of amyloid-βon neurite dynamics in both two-dimensional and three-dimensional cultu re systems,in order to provide more physiologically relevant culture geometry.We utilized various methodologies,including the addition of exogenous amyloid-βpeptides to the culture medium,growth substrate coating,and the utilization of human-induced pluripotent stem cell technology,to investigate the effect of endogenous amyloid-βsecretion on neurite outgrowth,thus paving the way for potential future applications in personalized medicine.Additionally,we also explore the involvement of the Nogo signaling cascade in amyloid-β-induced neurite inhibition.We demonstrate that inhibition of downstream ROCK and RhoA components of the Nogo signaling pathway,achieved through modulation with Y-27632(a ROCK inhibitor)and Ibuprofen(a Rho A inhibitor),respectively,can restore and even enhance neuronal connectivity in the presence of amyloid-β.In summary,this study not only presents a novel culture approach that offers insights into the biological process of neurite growth and inhibition,but also proposes a specific mechanism for reduced neural connectivity in the presence of amyloid-βpeptides,along with potential intervention points to restore neurite growth.Thereby,we aim to establish a culture system that has the potential to serve as an assay for measuring preclinical,predictive outcomes of drugs and their ability to promote neurite outgrowth,both generally and in a patient-specific manner.

Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

The combined application of stem cells and three-dimensional bioprinting scaffolds for the repair of spinal cord injury

Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.

The MORC2 p.S87L mutation reduces proliferation of pluripotent stem cells derived from a patient with the spinal muscular atrophy-like phenotype by inhibiting proliferation-related signaling pathways

Mutations in the microrchidia CW-type zinc finger protein 2(MORC2)gene are the causative agent of Charcot-Marie-Tooth disease type 2Z(CMT2Z),and the hotspot mutation p.S87L is associated with a more seve re spinal muscular atrophy-like clinical phenotype.The aims of this study were to determine the mechanism of the severe phenotype caused by the MORC2 p.S87L mutation and to explore potential treatment strategies.Epithelial cells were isolated from urine samples from a spinal muscular atrophy(SMA)-like patient[MORC2 p.S87L),a CMT2Z patient[MORC2 p.Q400R),and a healthy control and induced to generate pluripotent stem cells,which were then differentiated into motor neuron precursor cells.Next-generation RNA sequencing followed by KEGG pathway enrichment analysis revealed that differentially expressed genes involved in the PI3K/Akt and MAP K/ERK signaling pathways were enriched in the p.S87L SMA-like patient group and were significantly downregulated in induced pluripotent stem cells.Reduced proliferation was observed in the induced pluripotent stem cells and motor neuron precursor cells derived from the p.S87L SMA-like patient group compared with the CMT2Z patient group and the healthy control.G0/G1 phase cell cycle arrest was observed in induced pluripotent stem cells derived from the p.S87L SMA-like patient.MORC2 p.S87Lspecific antisense oligonucleotides(p.S87L-ASO-targeting)showed significant efficacy in improving cell prolife ration and activating the PI3K/Akt and MAP K/ERK pathways in induced pluripotent stem cells.Howeve r,p.S87L-ASO-ta rgeting did not rescue prolife ration of motor neuron precursor cells.These findings suggest that downregulation of the PI3K/Akt and MAP K/ERK signaling pathways leading to reduced cell proliferation and G0/G1 phase cell cycle arrest in induced pluripotent stem cells might be the underlying mechanism of the severe p.S87L SMA-like phenotype.p.S87L-ASO-targeting treatment can alleviate disordered cell proliferation in the early stage of pluripotent stem cell induction.

Multiple factors to assist human-derived induced pluripotent stem cells to efficiently differentiate into midbrain dopaminergic neurons

Midbrain dopaminergic neurons play an important role in the etiology of neurodevelopmental and neurodegenerative diseases.They also represent a potential source of transplanted cells for therapeutic applications.In vitro differentiation of functional midbrain dopaminergic neurons provides an accessible platform to study midbrain neuronal dysfunction and can be used to examine obstacles to dopaminergic neuronal development.Emerging evidence and impressive advances in human induced pluripotent stem cells,with tuned neural induction and differentiation protocols,makes the production of induced pluripotent stem cell-derived dopaminergic neurons feasible.Using SB431542 and dorsomorphin dual inhibitor in an induced pluripotent stem cell-derived neural induction protocol,we obtained multiple subtypes of neurons,including 20%tyrosine hydroxylase-positive dopaminergic neurons.To obtain more dopaminergic neurons,we next added sonic hedgehog(SHH)and fibroblast growth factor 8(FGF8)on day 8 of induction.This increased the proportion of dopaminergic neurons,up to 75%tyrosine hydroxylase-positive neurons,with 15%tyrosine hydroxylase and forkhead box protein A2(FOXA2)co-expressing neurons.We further optimized the induction protocol by applying the small molecule inhibitor,CHIR99021(CHIR).This helped facilitate the generation of midbrain dopaminergic neurons,and we obtained 31-74%midbrain dopaminergic neurons based on tyrosine hydroxylase and FOXA2 staining.Thus,we have established three induction protocols for dopaminergic neurons.Based on tyrosine hydroxylase and FOXA2 immunostaining analysis,the CHIR,SHH,and FGF8 combined protocol produces a much higher proportion of midbrain dopaminergic neurons,which could be an ideal resource for tackling midbrain-related diseases.

Advances in the differentiation of pluripotent stem cells into vascular cells

Blood vessels constitute a closed pipe system distributed throughout the body,transporting blood from the heart to other organs and delivering metabolic waste products back to the lungs and kidneys.Changes in blood vessels are related to many disorders like stroke,myocardial infarction,aneurysm,and diabetes,which are important causes of death worldwide.Translational research for new appro-aches to disease modeling and effective treatment is needed due to the huge socio-economic burden on healthcare systems.Although mice or rats have been widely used,applying data from animal studies to human-specific vascular physiology and pathology is difficult.The rise of induced pluripotent stem cells(iPSCs)provides a reliable in vitro resource for disease modeling,regenerative medicine,and drug discovery because they carry all human genetic information and have the ability to directionally differentiate into any type of human cells.This review summarizes the latest progress from the establishment of iPSCs,the strategies for differentiating iPSCs into vascular cells,and the in vivo trans-plantation of these vascular derivatives.It also introduces the application of these technologies in disease modeling,drug screening,and regenerative medicine.Additionally,the application of high-tech tools,such as omics analysis and high-throughput sequencing,in this field is reviewed.

Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential

BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent characteristics.AIM To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation potential.METHODS We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK mutation.Chromo-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC identification.Transcriptomics and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation potential.Additionally,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and differentiation.RESULTS The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic profiling.Furthermore,hiPSC-derived EVs were involved in various biological processes,including cell junction and differentiation.CONCLUSION HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation potential.Furthermore,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation.

Future of liver transplantation: Non-human primates for patient-specific organs from induced pluripotent stem cells

Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.

The combination of induced pluripotent stem cells and bioscaffolds holds promise for spinal cord regeneration

Spinal cord injuries（SCIs） are debilitating conditions for which no effective treatment currently exists. The damage of neural tissue causes disruption of neural tracts and neuron loss in the spinal cord. Stem cell replacement offers a solution for SCI treatment by providing a source of therapeutic cells for neural function restoration. Induced pluripotent stem cells（i PSCs） have been investigated as a potential type of stem cell for such therapies. Transplantation of i PSCs has been shown to be effective in restoring function after SCIs in animal models while they circumvent ethical and immunological concerns produced by other stem cell types. Another approach for the treatment of SCI involves the graft of a bioscaffold at the site of injury to create a microenvironment that enhances cellular viability and guides the growing axons. Studies suggest that a combination of these two treatment methods could have a synergistic effect on functional recovery post-neural injury. While much progress has been made, more research is needed before clinical trials are possible. This review highlights recent advancements using i PSCs and bioscaffolds for treatment of SCI.

Mucosal-associated invariant T cells from induced pluripotent stem cells:A novel approach for modeling human diseases

Mice have frequently been used to model human diseases involving immune dysregulation such as autoimmune and inflammatory diseases.These models help elucidatethe mechanisms underlying the disease and in the development of novel therapies.However,if mice are deficient in certain cells and/or effectors associated with human diseases,how can their functions be investigated in this species?Mucosal-associated invariant T(MAIT)cells,a novel innate-like T cell family member,are a good example.MAIT cells are abundant in humans but scarce in laboratory mice.MAIT cells harbor an invariant T cell receptor and recognize nonpeptidic antigens vitamin B2metabolites from bacteria and yeasts.Recent studies have shown that MAIT cells play a pivotal role in human diseases such as bacterial infections and autoimmune and inflammatory diseases.MAIT cells possess granulysin,a human-specific effector molecule,but granulysin and its homologue are absent in mice.Furthermore,MAIT cells show poor proliferation in vitro.To overcome these problems and further our knowledge of MAIT cells,we have established a method to expand MAIT cells via induced pluripotent stem cells(iP SCs).In this review,we describe recent advances in the field of MAIT cell research and our approach for human disease modeling with iP SCderived MAIT cells.

Human pluripotent stem cells:Towards therapeutic development for the treatment of lifestyle diseases

There are two types of human pluripotent stem cells: Embryonic stem cells(ESCs) and induced pluripotent stem cells(iPSCs),both of which launched themselves on clinical trials after having taken measures to overcome problems: Blocking rejections by immunosuppressants regarding ESCs and minimizing the risk of tumorigenicity by depleting exogenous gene components regarding iP SCs.It is generally assumed that clinical applications of human pluripotent stem cells should be limited to those cases where there are no alternative measures for treatments because of the risk in transplanting those cells to living bodies.Regarding lifestyle diseases,we have already several therapeutic options,and thus,development of human pluripotent stem cell-based therapeutics tends to be avoided.Nevertheless,human pluripotent stem cells can contribute to the development of new therapeutics in this field.As we will show,there is a case where only a short-term presence of human pluripotent stem-derived cells can exert long-term therapeutic effects even after they are rejected.In those cases,immunologically rejections of ESC-or allogenic iP SC-derived cells may produce beneficial outcomes by nullifying the risk of tumorigenesis without deterioration of therapeutic effects.Another utility of human pluripotent stem cells is the provision of an innovative tool for drug discovery that are otherwise unavailable.For example,clinical specimens of human classical brown adipocytes(BAs),which has been attracting a great deal of attention as a new target of drug discovery for the treatment of metabolic disorders,are unobtainable from living individuals due to scarcity,fragility and ethical problems.However,BA can easily be produced from human pluripotent stem cells.In this review,we will contemplate potential contribution of human pluripotent stem cells to therapeutic development for lifestyle diseases.

Induced pluripotent stem cells as a potential therapeutic source for corneal epithelial stem cells

Corneal blindness caused by limbal stem cell deficiency(LSCD) is one of the most common debilitating eye disorders. Thus far, the most effective treatment for LSCD is corneal transplantation, which is often hindered by the shortage of donors. Pluripotent stem cell technology including embryonic stem cells(ESCs) and induced pluripotent stem cells(iPSCs) have opened new avenues for treating this disease. iPSCs-derived corneal epithelial cells provide an autologous and unlimited source of cells for the treatment of LSCD. On the other hand, iPSCs of LSCD patients can be used for iPSCs-corneal disease model and new drug discovery. However, prior to clinical trial, the efficacy and safety of these cells in patients with LSCD should be proved. Here we focused on the current status of iPSCs-derived corneal epithelial cells used for cell therapy as well as for corneal disease modeling. The challenges and potential of iPSCs-derived corneal epithelial cells as a choice for clinical treatment in corneal disease were also discussed.

Search for naive human pluripotent stem cells

Normal mouse pluripotent stem cells were originally derived from the inner cell mass(ICM) of blastocysts and shown to be the in vitro equivalent of those pre-implantation embryonic cells, and thus were called embryonic stem cells(ESCs). More than a decade later, pluripotent cells were isolated from the ICM of human blastocysts. Despite being called human ESCs, these cells differ significantly from mouse ESCs, including different morphology and mechanisms of control of pluripotency, suggesting distinct embryonic origins of ESCs from the two species. Subsequently, mouse pluripotent stem cells were established from the ICMderived epiblast of post-implantation embryos. These mouse epiblast stem cells(Epi SCs) are morphological and epigenetically more similar to human ESCs. This raised the question of whether cells from the human ICM are in a more advanced differentiation stage than their murine counterpart, or whether the available culture conditions were not adequate to maintain those human cells in their in vivo state, leading to a transition into Epi SC-like cells in vitro. More recently, novel culture conditions allowed the conversion of human ESCs into mouse ESC-like cells called nave(or ground state) human ESCs, and the derivation of nave human ESCs from blastocysts. Here we will review the characteristics of each type of pluripotent stem cells, how(and whether) these relate to different stages of embryonic development, and discuss the potential implications of nave human ESCs in research and therapy.

Human induced pluripotent stem cells labeled with fluorescent magnetic nanoparticles for targeted imaging and hyperthermia therapy for gastric cancer

Objective: Human induced pluripotent stem(i PS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human i PS cells labeled with fluorescent magnetic nanoparticles(FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo. Methods: Human i PS cells were prepared and cultured for 72 h. The culture medium was collected, and then was coincubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human i PS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly. Results: iP S cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iP S cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field. Conclusion: FMNP-labeled human i PS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer.

Practical choice for robust and efficient differentiation of human pluripotent stem cells

Human pluripotent stem cells(hPSCs)have the distinct advantage of being able to differentiate into cells of all three germ layers.Target cells or tissues derived from hPSCs have many uses such as drug screening,disease modeling,and transplantation therapy.There are currently a wide variety of differentiation methods available.However,most of the existing differentiation methods are unreliable,with uneven differentiation efficiency and poor reproducibility.At the same time,it is difficult to choose the optimal method when faced with so many differentiation schemes,and it is time-consuming and costly to explore a new differentiation approach.Thus,it is critical to design a robust and efficient method of differentiation.In this review article,we summarize a comprehensive approach in which hPSCs are differentiated into target cells or organoids including brain,liver,blood,melanocytes,and mesenchymal cells.This was accomplished by employing an embryoid body-based three-dimensional(3D)suspension culture system with multiple cells co-cultured.The method has high stable differentiation efficiency compared to the conventional 2D culture and can meet the requirements of clinical application.Additionally,ex vivo co-culture models might be able to constitute organoids that are highly similar or mimic human organs for potential organ transplantation in the future.