BACKGROUND: Synaptic dysfunction is a major contributor to Alzheimeŕs disease (AD) pathogenesis in addition to the formation of neuritic β-amyloid plaques and neurofibrillary tangles of hyperphosphorylated Tau protein. However, how these features contribute to synaptic dysfunction and axonal loss remains unclear. While years of considerable effort have been devoted to gaining an improved understanding of this devastating disease, the unavailability of patient-derived tissues, considerable genetic heterogeneity, and lack of animal models that faithfully recapitulate human AD have hampered the development of effective treatment options. Ongoing progress in human induced pluripotent stem cell (hiPSC) technology has permitted the derivation of patient- and disease-specific stem cells with unlimited self-renewal capacity. These cells can differentiate into AD-affected cell types, which support studies of disease mechanisms, drug discovery, and the development of cell replacement therapies in traditional and advanced cell culture models. AIM OF REVIEW: To summarize current hiPSC-based AD models, highlighting the associated achievements and challenges with a primary focus on neuron and synapse loss. KEY SCIENTIFIC CONCEPTS OF REVIEW: We aim to identify how hiPSC models can contribute to understanding AD-associated synaptic dysfunction and axonal loss. hiPSC-derived neural cells, astrocytes, and microglia, as well as more sophisticated cellular organoids, may represent reliable models to investigate AD and identify early markers of AD-associated neural degeneration.

• Klíčová slova
• Alzheimer's disease, Astrocytes, Brain organoids, Induced pluripotent stem cells, Microglia, Neural differentiation, Neuronal loss, Neurons,
• MeSH
• Alzheimerova nemoc * genetika   metabolismus   patologie   MeSH
• amyloidní beta-protein genetika   metabolismus   MeSH
• indukované pluripotentní kmenové buňky * metabolismus   patologie   MeSH
• lidé MeSH
• neurony metabolismus   MeSH
• synapse metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• amyloidní beta-protein MeSH

During the past two decades, induced pluripotent stem cells (iPSCs) have been widely used to study human neural development and disease. Especially in the field of Alzheimer's disease (AD), remarkable effort has been put into investigating molecular mechanisms behind this disease. Then, with the advent of 3D neuronal cultures and cerebral organoids (COs), several studies have demonstrated that this model can adequately mimic familial and sporadic AD. Therefore, we created an AD-CO model using iPSCs derived from patients with familial AD forms and explored early events and the progression of AD pathogenesis. Our study demonstrated that COs derived from three AD-iPSC lines with PSEN1(A246E) or PSEN2(N141I) mutations developed the AD-specific markers in vitro, yet they also uncover tissue patterning defects and altered development. These findings are complemented by single-cell sequencing data confirming this observation and uncovering that neurons in AD-COs likely differentiate prematurely.

• Klíčová slova
• Alzheimer’s disease, CP: Developmental biology, CP: Neuroscience, cerebral organoids, development, induced pluripotent stem cells, single-cell mRNA sequencing,
• MeSH
• Alzheimerova nemoc * genetika   patologie   MeSH
• indukované pluripotentní kmenové buňky patologie   MeSH
• lidé MeSH
• mutace genetika   MeSH
• neurony MeSH
• organoidy patologie   MeSH
• presenilin-1 * genetika   MeSH
• presenilin-2 * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• presenilin-1 * MeSH
• presenilin-2 * MeSH
• PSEN1 protein, human MeSH Prohlížeč
• PSEN2 protein, human MeSH Prohlížeč

Hereditary retinal dystrophies (HRD) represent a significant cause of blindness, affecting mostly retinal pigment epithelium (RPE) and photoreceptors (PRs), and currently suffer from a lack of effective treatments. Highly specialized RPE and PR cells interact mutually in the functional retina, therefore primary HRD affecting one cell type leading to a secondary HRD in the other cells. Phagocytosis is one of the primary functions of the RPE and studies have discovered that mutations in the phagocytosis-associated gene Mer tyrosine kinase receptor (MERTK) lead to primary RPE dystrophy. Treatment strategies for this rare disease include the replacement of diseased RPE with healthy autologous RPE to prevent PR degeneration. The generation and directed differentiation of patient-derived human-induced pluripotent stem cells (hiPSCs) may provide a means to generate autologous therapeutically-relevant adult cells, including RPE and PR. However, the continued presence of the MERTK gene mutation in patient-derived hiPSCs represents a significant drawback. Recently, we reported the generation of a hiPSC model of MERTK-associated Retinitis Pigmentosa (RP) that recapitulates disease phenotype and the subsequent creation of gene-corrected RP-hiPSCs using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9. In this study, we differentiated gene-corrected RP-hiPSCs into RPE and found that these cells had recovered both wild-type MERTK protein expression and the lost phagocytosis of fluorescently-labeled photoreceptor outer segments observed in uncorrected RP-hiPSC-RPE. These findings provide proof-of-principle for the utility of gene-corrected hiPSCs as an unlimited cell source for personalized cell therapy of rare vision disorders.

• Klíčová slova
• RPE, Retinitis Pigmentosa, gene correction, induced pluripotent stem cells,
• MeSH
• buněčná diferenciace genetika   MeSH
• buněčné linie MeSH
• editace genu * MeSH
• fagocytóza * MeSH
• indukované pluripotentní kmenové buňky patologie   ultrastruktura   MeSH
• lidé MeSH
• mutace genetika   MeSH
• regulace genové exprese MeSH
• retinální pigmentový epitel patologie   ultrastruktura   MeSH
• retinopathia pigmentosa genetika   patologie   MeSH
• tyrosinkinasa c-Mer genetika   metabolismus   MeSH
• zevní segment fotoreceptoru sítnice metabolismus   patologie   ultrastruktura   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• tyrosinkinasa c-Mer MeSH

Inflammatory and oncogenic signaling converge in disease evolution of BCR-ABL-negative myeloproliferative neoplasms, clonal hematopoietic stem cell disorders characterized by gain-of-function mutation in JAK2 kinase (JAK2V617F), with highest prevalence in patients with polycythemia vera (PV). Despite the high risk, DNA-damaging inflammatory microenvironment, PV progenitors tend to preserve their genomic stability over decades until their progression to post-PV myelofibrosis/acute myeloid leukemia. Using induced pluripotent stem cells-derived CD34+ progenitor-enriched cultures from JAK2V617F+ PV patient and from JAK2 wild-type healthy control, CRISPR-modified HEL cells and patients' bone marrow sections from different disease stages, we demonstrate that JAK2V617F induces an intrinsic IFNγ- and NF-κB-associated inflammatory program, while suppressing inflammation-evoked DNA damage both in vitro and in vivo. We show that cells with JAK2V617F tightly regulate levels of inflammatory cytokines-induced reactive oxygen species, do not fully activate the ATM/p53/p21waf1 checkpoint and p38/JNK MAPK stress pathway signaling when exposed to inflammatory cytokines, suppress DNA single-strand break repair genes' expression yet overexpress the dual-specificity phosphatase (DUSP) 1. RNAi-mediated knock-down and pharmacological inhibition of DUSP1, involved in p38/JNK deactivation, in HEL cells reveals growth addiction to DUSP1, consistent with enhanced DNA damage response and apoptosis in DUSP1-inhibited parental JAK2V617F+ cells, but not in CRISPR-modified JAK2 wild-type cells. Our results indicate that the JAK2V617F+ PV progenitors utilize DUSP1 activity as a protection mechanism against DNA damage accumulation, promoting their proliferation and survival in the inflammatory microenvironment, identifying DUSP1 as a potential therapeutic target in PV.

• MeSH
• cytokiny genetika   metabolismus   MeSH
• fosfatasa 1 s dvojí specificitou genetika   MeSH
• hematopoetické kmenové buňky patologie   MeSH
• indukované pluripotentní kmenové buňky patologie   MeSH
• Janus kinasa 2 genetika   MeSH
• lidé MeSH
• mutace MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí MeSH
• oxidační stres * MeSH
• polycythaemia vera genetika   MeSH
• poškození DNA * MeSH
• proliferace buněk * MeSH
• reprodukovatelnost výsledků MeSH
• transkripční faktor STAT1 metabolismus   MeSH
• zánět metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokiny MeSH
• DUSP1 protein, human MeSH Prohlížeč
• fosfatasa 1 s dvojí specificitou MeSH
• JAK2 protein, human MeSH Prohlížeč
• Janus kinasa 2 MeSH
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 MeSH

Recent data on Duchenne muscular dystrophy (DMD) show myocyte progenitor's involvement in the disease pathology often leading to the DMD patient's death. The molecular mechanism underlying stem cell impairment in DMD has not been described. We created dystrophin-deficient human pluripotent stem cell (hPSC) lines by reprogramming cells from two DMD patients, and also by introducing dystrophin mutation into human embryonic stem cells via CRISPR/Cas9. While dystrophin is expressed in healthy hPSC, its deficiency in DMD hPSC lines induces the release of reactive oxygen species (ROS) through dysregulated activity of all three isoforms of nitric oxide synthase (further abrev. as, NOS). NOS-induced ROS release leads to DNA damage and genomic instability in DMD hPSC. We were able to reduce both the ROS release as well as DNA damage to the level of wild-type hPSC by inhibiting NOS activity.

• Klíčová slova
• DMD, NO synthases, ROS, dystrophin, genome stability, pluripotent stem cells,
• MeSH
• buněčné linie MeSH
• Duchennova muskulární dystrofie genetika   MeSH
• dystrofin nedostatek   genetika   MeSH
• indukované pluripotentní kmenové buňky metabolismus   patologie   MeSH
• lidé MeSH
• nestabilita genomu * MeSH
• oxidační stres MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• synthasa oxidu dusnatého, typ I metabolismus   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• synthasa oxidu dusnatého, typ III metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dystrofin MeSH
• NOS1 protein, human MeSH Prohlížeč
• NOS2 protein, human MeSH Prohlížeč
• NOS3 protein, human MeSH Prohlížeč
• reaktivní formy kyslíku MeSH
• synthasa oxidu dusnatého, typ I MeSH
• synthasa oxidu dusnatého, typ II MeSH
• synthasa oxidu dusnatého, typ III MeSH

Hereditary retinal dystrophies, specifically retinitis pigmentosa (RP) are clinically and genetically heterogeneous diseases affecting primarily retinal cells and retinal pigment epithelial cells with blindness as a final outcome. Understanding the pathogenicity behind these diseases has been largely precluded by the unavailability of affected tissue from patients, large genetic heterogeneity and animal models that do not faithfully represent some human diseases. A landmark discovery of human induced pluripotent stem cells (hiPSCs) permitted the derivation of patient-specific cells. These cells have unlimited self-renewing capacity and the ability to differentiate into RP-affected cell types, allowing the studies of disease mechanism, drug discovery, and cell replacement therapies, both as individual cell types and organoid cultures. Together with precise genome editing, the patient specific hiPSC technology offers novel strategies for targeting the pathogenic mutations and design therapies toward retinal dystrophies. This study summarizes current hiPSC-based RP models and highlights key achievements and challenges of these cellular models, as well as questions that still remain unanswered. Stem Cells 2018;36:474-481.

• Klíčová slova
• Differentiation, Gene targeting, Induced pluripotent stem, Induced pluripotent stem cells, Retina, Retinal photoreceptors, Retinal pigmented epithelium,
• MeSH
• autologní štěp MeSH
• buněčná diferenciace * MeSH
• editace genu * MeSH
• genom lidský * MeSH
• indukované pluripotentní kmenové buňky metabolismus   patologie   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• retinopathia pigmentosa * genetika   metabolismus   patologie   terapie   MeSH
• transplantace kmenových buněk * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Mucopolysaccharidosis type II (MPSII) is a rare X-linked lysosomal storage disorder caused by mutations in the iduronate-2-sulfatase (IDS) gene (IDS, Xq28). MPSII is characterized by skeletal deformities, hearing loss, airway obstruction, hepatosplenomegaly, cardiac valvular disease, and progressive neurological impairment. At the cellular level, IDS deficiency leads to lysosomal storage of glycosaminoglycans (GAGs), dominated by accumulation of dermatan and heparan sulfates. Human induced pluripotent stem cells (iPSC) represent an alternative system that complements the available MPSII murine model. Herein we report on the reprogramming of peripheral white blood cells from male and female MPSII patients into iPSC using a non-integrating protocol based on the Sendai virus vector system. We differentiated the iPSC lines into IDS deficient and GAG accumulating β-Tubulin III+ neurons, GFAP+ astrocytes, and CNPase+ oligodendrocytes. The lysosomal system in these cells displayed structural abnormalities reminiscent of those previously found in patient tissues and murine IDS deficient neuronal stem cells. Furthermore, quantitative determination of GAGs revealed a moderate increase in GAG levels in IDS deficient neurons and glia. We also tested the effects of recombinant IDS and found that the exogenous enzyme was internalized from the culture media and partially decreased the intracellular GAG levels in iPSC-derived neural cells; however, it failed to completely prevent accumulation of GAGs. In summary, we demonstrate that this human iPSC based model expresses the cellular and biochemical features of MPSII, and thus represents a useful experimental tool for further pathogenesis studies as well as therapy development and testing.

• MeSH
• astrocyty enzymologie   patologie   MeSH
• buněčný rodokmen MeSH
• fenotyp MeSH
• glykosaminoglykany metabolismus   MeSH
• iduronátsulfatasa genetika   metabolismus   MeSH
• indukované pluripotentní kmenové buňky enzymologie   patologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• lyzozomy enzymologie   patologie   MeSH
• mukopolysacharidóza II enzymologie   genetika   patologie   MeSH
• nervové kmenové buňky enzymologie   patologie   MeSH
• neurogeneze * MeSH
• neuroglie enzymologie   patologie   MeSH
• neurony enzymologie   patologie   MeSH
• oligodendroglie enzymologie   patologie   MeSH
• prekurzorové buňky oligodendrocytů enzymologie   patologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glykosaminoglykany MeSH
• iduronátsulfatasa MeSH

Hypoplastic left heart syndrome (HLHS) is a serious congenital cardiovascular malformation resulting in hypoplasia or atresia of the left ventricle, ascending aorta, and aortic and mitral valves. Diminished flow through the left side of the heart is clearly a key contributor to the condition, but any myocardial susceptibility component is as yet undefined. Using recent advances in the field of induced pluripotent stem cells (iPSCs), we have been able to generate an iPSC model of HLHS malformation and characterize the properties of cardiac myocytes (CMs) differentiated from these and control-iPSC lines. Differentiation of HLHS-iPSCs to cardiac lineages revealed changes in the expression of key cardiac markers and a lower ability to give rise to beating clusters when compared with control-iPSCs and human embryonic stem cells (hESCs). HLHS-iPSC-derived CMs show a lower level of myofibrillar organization, persistence of a fetal gene expression pattern, and changes in commitment to ventricular versus atrial lineages, and they display different calcium transient patterns and electrophysiological responses to caffeine and β-adrenergic antagonists when compared with hESC- and control-iPSC-derived CMs, suggesting that alternative mechanisms to release calcium from intracellular stores such as the inositol trisphosphate receptor may exist in HLHS in addition to the ryanodine receptor thought to function in control-iPSC-derived CMs. Together our findings demonstrate that CMs derived from an HLHS patient demonstrate a number of marker expression and functional differences to hESC/control iPSC-derived CMs, thus providing some evidence that cardiomyocyte-specific factors may influence the risk of HLHS.

• Klíčová slova
• Cardiac development, Cardiac myocytes, Hypoplastic left heart syndrome, Induced pluripotent stem cells, Pluripotent stem cell differentiation,
• MeSH
• biologické modely * MeSH
• indukované pluripotentní kmenové buňky metabolismus   patologie   MeSH
• kardiomyocyty metabolismus   patologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• novorozenec MeSH
• regulace genové exprese * MeSH
• svalové proteiny biosyntéza   MeSH
• syndrom hypoplazie levého srdce metabolismus   patologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• svalové proteiny MeSH