iPSCs

Oculocutaneous albinism (OCA) is a group of hereditary recessive disorder recognized as a loss of pigmentation. OCA can derive from mutations in different genes that produce melanin. These mutations cause disturbances to get a standard melanin synthesis. There are 7 types of oculocutaneous albinism. These include OCA1, OCA2, OCA3, OCA4, OCA5, OCA6, and OCA7. To help OCA patients, it may include management of such as hats with brims and sunscreens. An effective therapy is unavailable for albinism at present. However, to fight OCA in the future, gene therapy can be used. Gene therapy can include use of such as retrovirus vectors, adenovirus vectors, and CRISPR/Cas9 system. Research results in animal models have shown remarkable advances. It means that the gene therapy will be helpful to treat people with albinism.

This review summarizes the structural and electrophysiological changes in the epileptic hippocampus in various animal models of epilepsy. Tornado hypothesis of epileptic hippocampus, states that there are many progressive detrimental changes in the hippocampus of the epileptic rats. PTZ, PTZ kindling, pilocarpine, electrical kindling, kainic acid, hyperthermia and in vitro models are taken as primary animal epilepsy models in this review. Paired pulse inhibition and GABAergic transmission is decreased in dentate gyrus (DG), CA3 and CA1 regions of the epileptic hippocampus. There is interneuron loss in the hilus, DG and CA3, while excitatory input from perforant path (PP) is increased and this is fed into the CA3 area by mossy fibers (MF) which have excessive sprouting that forms novel recurrent synapses with the pyramidal cells of CA3. Gate function of DG is either impaired or lost. CA3 area of hippocampus becomes an epileptic focus and sends ictal discharges. These ictal discharges are carried into CA1 by Schaffer collaterals and then into entorhinal cortex (EC). The input from EC is amplified in the hippocampal circuitry which is fed into hippocampus from EC into DG again successively. Thus, a weak electrical input into the hippocampal formation results in an amplified signal back into EC. Since the basic ultrastructural and electrophysiological feedback control mechanisms are impaired, this electrical tornado cannot be compensated for and an epileptic amplified ictal discharge spreads to the limbic system and other adjacent structures of the brain. Eventually the hippocampal circuitry, that has developed a vicious circle, becomes a bio-electrical amplifier which triggers an electrical tornado, under certain biochemical conditions. mossy fiber sprouting, in vitro model of epilepsy, perforant path, tonic clonic seizures, intractable temporal lobe epilepsy.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two age-dependent multifactorial neurodegenerative disorders, which are typically characterized by the selective death of motor neurons and cerebral cortex neurons, respectively. These two diseases share many clinical, genetic and pathological aspects. During the past decade, cell reprogramming technologies enabled researchers to generate human induced pluripotent stem cells (iPSCs) from somatic cells. This resulted in the unique opportunity to obtain specific neuronal and non-neuronal cell types from patients which could be used for basic research. Moreover, these in vitro models can mimic not only the familial forms of ALS/FTD, but also sporadic cases without known genetic cause. At present, there have been extensive technical advances in the generation of iPSCs, as well as in the differentiation procedures to obtain iPSC-derived motor neurons, cortical neurons and non-neuronal cells. The major challenge at this moment is to determine whether these iPSC-derived cells show relevant phenotypes that recapitulate complex diseases. In this review, we will summarize the work related to iPSC models of ALS and FTD. In addition, we will discuss potential drawbacks and solutions for establishing more trustworthy iPSC models for both ALS and FTD.

Age related macular degeneration (AMD) is the most common cause of blindness, accounting for 8.7% of all blindness globally. Vision loss is caused ultimately by apoptosis of the retinal pigment epithelium (RPE) and overlying photoreceptors. Treatments are evolving for the wet form of the disease, however these do not exist for the dry form. Complement factor H (CFH) polymorphism in exon 9 (Y402H) has shown a strong association with susceptibility to AMD resulting in complement activation, recruitment of phagocytes, retinal pigment epithelium (RPE) damage and visual decline. We have derived and characterised induced pluripotent stem cell (iPSCs) lines from two patients without AMD and low risk genotype and two pa‐ tients with advanced AMD and high risk genotype and generated RPE cells that show local secretion of several proteins involved in the complement pathway including factor H (FH), factor I (FI) and factor H like 1 (FHL‐1). The iPSC RPE cells derived from high risk patients mimic several key features of AMD including increased inflammation and cellular stress, accumulation of lipid droplets, impaired autophagy and deposition of " drüsen " like depos‐ its. The low and high risk RPE cells respond differently to intermittent ex‐ posure to UV light which leads to an improvement in cellular and function‐ al phenotype only in the high risk AMD‐RPE cells. Taken together our data indicate that the patient specific iPSC model provides a robust platform for understanding the role of complement activation in AMD, evaluating new therapies based on complement modulation and drug testing. STEM CELLS 2017; 00:000–000 SIGNIFICANCE STATEMENT: Age related macular degeneration (AMD) is the one of the most common forms of blindness. Drugs that treat wet AMD have been a major break‐ through; however there is currently no treatment for the dry form. One of the problems with studying AMD is that the affected retinal tissue is difficult to obtain, there are no animal models that faithfully mimic the disease and human trials are long and costly. Herein, we report creation of a disease

Generation of induced pluripotent stem cells (iPSCs) by somatic cell reprogramming involves global epigenetic remodelling. Whereas several proteins are known to regulate chromatin marks associated with the distinct epigenetic states of cells before and after reprogramming, the role of specific chromatin-modifying enzymes in reprogramming remains to be determined. To address how chromatin-modifying proteins influence reprogramming, we used short hairpin RNAs (shRNAs) to target genes in DNA and histone methylation pathways, and identified positive and negative modulators of iPSC generation. Whereas inhibition of the core components of the polycomb repressive complex 1 and 2, including the histone 3 lysine 27 methyltransferase EZH2, reduced reprogramming efficiency, suppression of SUV39H1, YY1 and DOT1L enhanced reprogramming. Specifically, inhibition of the H3K79 histone methyltransferase DOT1L by shRNA or a small molecule accelerated reprogramming, significantly increased the yield of iPSC colonies, and substituted for KLF4 and c-Myc (also known as MYC). Inhibition of DOT1L early in the reprogramming process is associated with a marked increase in two alternative factors, NANOG and LIN28, which play essential functional roles in the enhancement of reprogramming. Genome-wide analysis of H3K79me2 distribution revealed that fibroblast-specific genes associated with the epithelial to mesenchymal transition lose H3K79me2 in the initial phases of reprogramming. DOT1L inhibition facilitates the loss of this mark from genes that are fated to be repressed in the pluripotent state. These findings implicate specific chromatin-modifying enzymes as barriers to or facilitators of reprogramming, and demonstrate how modulation of chromatin-modifying enzymes can be exploited to more efficiently generate iPSCs with fewer exogenous transcription factors.

Hemophilia A is a hemorrhage disorder inherited according to the X-linked inheritance pattern. It affects about 1 in 4,000 to 10,000 males. Permanent changes in the F8 gene result in hemophilia A. These changes result in an abnormal version of coagulation factor VIII. This abnormal condition determines the kinds of the disorder, namely, severe and mild or moderate hemophilia A. Currently, to treat hemophilia A, infusions of plasma-derived or recombinant factor VIII can be used. However, the cost is extremely high. It makes heavy burdens on the patients, their families or the health care system. Therefore, advanced therapy as iPSCs technique has attracted attention of researchers to research for curing this disorder. For example, to obtain edited DNA segments due to hemophilia A, this technique can be used. Research results in animal models have shown important advances.

Reprogramming somatic cells into induced pluripotent stem (iPS) cells is nowadays approaching effectiveness and
clinical grade. Potential uses of this technology include predictive toxicology, drug screening, pathogenetic studies and
transplantation. Here, we review the basis of current iPS cell technology and potential applications in hematology,
ranging from disease modeling of congenital and acquired hemopathies to hematopoietic stem and other blood cell
transplantation.

Despite the high heritability of schizophrenia (SCZ), details of its pathophysiology and etiology are still unknown. Recent findings suggest that aberrant inflammatory regulation and microRNAs (miRNAs) are involved. Here we performed a comparative analysis of the global miRNome of human induced pluripotent stem cell (iPSC)-astrocytes, derived from SCZ patients and healthy controls (CTRLs), at baseline and following inflam-matory modulation using IL-1β. We identified four differentially expressed miRNAs (miR-337-3p, miR-127-5p, miR-206, miR-1185-1-3p) in SCZ astrocytes that exhibited significantly lower baseline expression relative to CTRLs. Group-specific differential expression (DE) analyses exploring possible distinctions in the modulatory capacity of IL-1β on miRNA expression in SCZ versus CTRL astroglia revealed trends toward altered miRNA expressions. In addition, we analyzed peripheral blood samples from a large cohort of SCZ patients (n = 484) and CTRLs (n = 496) screening for the expression of specific gene targets of the four DE miRNAs that were identified in our baseline astrocyte setup. Three of these genes, LAMTOR4, IL23R, and ERBB3, had a significantly lower expression in the blood of SCZ patients compared to CTRLs after multiple testing correction. We also found nominally significant differences for ERBB2 and IRAK1, which similarly displayed lower expressions in SCZ versus CTRL. Furthermore, we found matching patterns between the expressions of identified miRNAs and their target genes when comparing our in vitro and in vivo results. The current results further our understanding of the pathobiological basis of SCZ.

Peripheral blood mononuclear cells (PBMCs) were collected from a clinically characterised 63-year old woman with late onset Alzheimer's disease (LOAD). The PMBCs were reprogrammed with the human OSKM transcription factors using the Sendai-virus delivery system. The transgene-free iPSC showed pluripotency verified by im-munocytochemistry for pluripotency markers and differentiated spontaneously towards the 3 germ layers in vitro. Furthermore, the iPSC line showed normal karyotype. Our model might offer a good platform to further study the pathomechanism of sporadic AD, to identify early biomarkers and also for drug testing and gene therapy studies.

С появлением революционной технологии перепрограммирования соматических клеток в омоложенные стволовые клетки, называемые индуцированными стволовыми клетками (ИПСК),  человечество, казалось бы, получило фонтан вечной молодости и здоровья. Однако врачи не спешат использовать чудо-клетки для исцеления больных, так как  лечение с их помощью оказалось сопряжено с риском заболеть раком. Как же надежно  обезопасить терапию клетками полученными из ИПСК? Этот миниобзор посвящен новейшим разработкам и достижениям в разрешении этой задачи.

The Notch-signaling pathway is known to be fundamental in controlling pancreas differentiation. We now report on using Crebased fate mapping to indelibly label pancreatic Notch-responsive cells (PNCs) at larval stages and follow their fate in the adult pancreas. We show that the PNCs represent a population of progenitors that can differentiate to multiple lineages, including adult ductal cells, centroacinar cells (CACs) and endocrine cells. These endocrine cells include the insulin-producing -cells. CACs are a functional component of the exocrine pancreas; however, our fate-mapping results indicate that CACs are more closely related to endocrine cells by lineage as they share a common progenitor. The majority of the exocrine pancreas consists of the secretory acinar cells; however, we only detect a very limited contribution of PNCs to acinar cells. To explain this observation we re-examined early events in pancreas formation. The pancreatic anlage that gives rise to the exocrine pancreas is located in the ventral gut endoderm (called the ventral bud). Ptf1a is a gene required for exocrine pancreas development and is first expressed as the ventral bud forms. We used transgenic marker lines to observe both the domain of cells expressing ptf1a and cells responding to Notch signaling. We do not detect any overlap in expression and demonstrate that the ventral bud consists of two cell populations: a ptf1-expressing domain and a Notch-responsive progenitor core. As pancreas organogenesis continues, the ventral bud derived PNCs align along the duct, remain multipotent and later in development differentiate to form secondary islets, ducts and CACs.

Schizophrenia (SCZ) is a severe mental disorder with a high heritability. Although its pathophysiology is mainly unknown, dysregulated immune activation and inflammation have recently emerged as possible candidates in the underlying mechanisms of SCZ. Previous studies suggest that aberrant inflammasome activation, glia dys-regulation, and brain inflammation may be involved in the pathophysiology of the disorder. Here, we studied the effects of inflammatory modulation on human induced pluripotent stem cell (iPSC)-derived astrocytes generated from SCZ patients and healthy controls (CTRL). Inflammasome activation was mimicked by short-term IL-1β exposure, and gene expression were measured with high-coverage RNA-Seq to ensure a global characterization of the transcriptional effects of the treatment. IL-1β exposure modulated several pathways involved in innate immune responses, cell cycle regulation, and metabolism in both SCZ and CTRL astrocytes. Significant differences were found in the expression of HILPDA and CCL20 genes, both of which had reduced up-regulation upon IL-1β treatment in SCZ astrocytes compared to CTRL astrocytes. CCL20 data were further validated and confirmed using qPCR, ELISA, and regulatory T lymphocyte (T reg) migration assays. Additionally, we found significantly decreased mRNA expression of the T reg-specific marker FOXP3 in the blood of a large cohort of SCZ patients (n = 484) compared to CTRL (n = 472). Since CCL20 is a specific chemoattractant for CD4 + CD25 + CCR6 + T regs , which are crucially involved in anti-inflammatory responses during brain (auto)in-flammation, our results imply a plausible role for an altered astroglia-CCL20-CCR6-T reg axis in SCZ pathophy-siology.

Human-induced pluripotent stem cells (hiPSCs) and CRISPR/Cas9 gene editing system represent two instruments of basic and translational research, which both allow to acquire deep insight about the molecular bases of many diseases but also to develop pharmacological research.This review is focused to draw up the latest technique of gene editing applied on hiPSCs, exploiting some of the genetic manipulation directed to the discovery of innovative therapeutic strategies. There are many expediencies provided by the use of hiPSCs, which can represent a disease model clinically relevant and predictive, with a great potential if associated to CRISPR/Cas9 technology, a gene editing tool powered by ease and precision never seen before.Here, we describe the possible applications of CRISPR/Cas9 to hiPSCs: from drug development to drug screening and from gene therapy to the induction of the immunological response to specific virus infection, such as HIV and SARS-Cov-2.

Induced pluripotent stem cells (iPSCs) are a type of pluripotent cells that generate by reprogramming somatic cells. The interaction between transcription factors, signalling regulators and epigenetic modifications which occur in pluripotent stem cells, are important for reprogramming of somatic cells into iPSCs. Different reprogramming factors are used for deriving pluripotent stem cells artificially, mainly through targeting the key pluripotency and differentiation genes. In this protocol, we describe how to derive iPSCs by lentiviral transduction of miR302. The effect of miR302 on reprogrammed cells is determined by the of expression of different phenotypic, signalling and epigenetics markers.

Age-related macular degeneration (AMD) is the most common cause of blindness, accounting for 8.7% of all blindness globally. Vision loss is caused ultimately by apoptosis of the retinal pigment epithelium (RPE) and overlying photoreceptors. Treatments are evolving for the wet form of the disease; however, these do not exist for the dry form. Complement factor H polymorphism in exon 9 (Y402H) has shown a strong association with susceptibility to AMD resulting in complement activation, recruitment of phagocytes, RPE damage, and visual decline. We have derived and characterized induced pluripotent stem cell (iPSC) lines from two subjects without AMD and low-risk genotype and two patients with advanced AMD and high-risk genotype and generated RPE cells that show local secretion of several proteins involved in the complement pathway including factor H, factor I, and factor H-like protein 1. The iPSC RPE cells derived from high-risk patients mimic several key features of AMD including inc...

Dua tokoh utama adalah yang sangat populer menjembatani pengetahuan medis yang sangat reduksionis dan basic science, biolgi, yaitu Sir John Gurdon dan Shinya Yamanaka. Sir John Gurdon adalah professeor biologi pertama yang mendapatkan sel embrional dari transplantasi inti sel intestinal katak ke sel telur yang dienukleasi. Hal ini membuka pandangan manusia bahwa faktor-faktor tertentu di sel-sel yang belum terdiferensiasi dapat memunculkan sifat embrional layaknya sel-sel embri. Shinya Yamanaka adalah seorang dokter bedah ortopedi Osaka dan Ph.D. di bidang biologi molekuler. Yamanaka mendapat tantangan untuk menciptakan sesuatu yang unik dan sangat menantang ketika melamar pekerjaan di universitas, dan dengan idenya untuk mendapatkan kembali sel punsa dari sel-sel yang telah terdiferensiasi, Yamanaka akhirnya menemukan 4 faktor ranskripsi utama yang bertanggung jawab terhadap pluripotensi adalah Oct3/4, Sox1, cMyc, Kif4 yang tidak dimiliki oleh sel-sel terdiferensiasi. Dengan pengetahuan tersebut mereka pertama kali menemukan sel-sel pluripotesi dari sel-sel yang telah terdiferensiasi. Mereka mendapatkan hadiah nobel di tahun 2012.

Translation of pharmacological results from in vitro cell testing to clinical trials is challenging. One of the causes that may underlie these discrepant results is the lack of the phenotypic or species-specific relevance of the tested cells; today, this lack of relevance may be reduced by relying on cells differentiated from human pluripotent stem cells. To analyse the benefits provided by this approach, we chose to focus on Friedreich ataxia, a neurodegenerative condition for which the recent clinical testing of two compounds was not successful. These compounds, namely, resveratrol and nicotinamide, were selected because they had been shown to stimulate the expression of frataxin in fibroblasts and lymphoblastoid cells. Our results indicated that these compounds failed to do so in iPSC-derived neurons generated from two patients with Friedreich ataxia. By comparing the effects of both molecules on different cell types that may be considered to be non-relevant for the disease, such as fibroblasts, or more relevant to the disease, such as neurons differentiated from iPSCs, a differential
response was observed; this response suggests the importance of developing more predictive in vitro systems for drug discovery. Our results demonstrate the value of utilizing human iPSCs early in drug discovery to improve translational predictability.

Liver transplantation remains the only solution for patients suffering from severe end-stage liver disease. Only 33% of these patients on the transplant waiting list will receive a donation; furthermore, the demand for livers is expected to increase over 20% in the next two decades. Available liver donations are limited now more than ever. Stem cell therapies using human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) are being developed to provide cell therapies in order to bypass orthopedic liver transplantation. Additionally, hESCs and hiPSCs are applied in drug development and screening to help pharmaceuticals manufacture more efficacious drugs and in disease modeling allowing scientists to understand disease progression. Clinical cell therapy trials using hepatocyte transplantation have produced promising initial results. Despite continued advances, the effectiveness of transplanted hepatocytes declines within several months and a liver transplant is still necessary. The current advantage of using cell therapy models is to prolong functional use of a diseased liver until a donor liver is received. The potential use of hiPSCs differentiated into hepatocyte cells (hiPSC-HEPs) can generate an infinite supply of hepatic cells. HiPSCs provide a crucial research platform in the development of more effective protocols for cell therapy, drug development and disease modeling.

Generation of induced pluripotent stem cells (iPSCs) by somatic cell reprogramming involves global epigenetic remodelling 1. Whereas several proteins are known to regulate chromatin marks associated with the distinct epigenetic states of cells before and after reprogramming 2, 3, the role of specific chromatin-modifying enzymes in reprogramming remains to be determined. To address how chromatin-modifying proteins influence reprogramming, we used short hairpin RNAs (shRNAs) to target genes in DNA and ...