A key challenge for clinical application of induced pluripotent stem cells (iPSC) to accurately model and treat human pathologies depends on developing a method to generate genetically stable cells ...to reduce long‐term risks of cell transplant therapy. Here, we hypothesized that CYCLIN D1 repairs DNA by highly efficient homologous recombination (HR) during reprogramming to iPSC that reduces genetic instability and threat of neoplastic growth. We adopted a synthetic mRNA transfection method using clinically compatible conditions with CYCLIN D1 plus base factors (OCT3/4, SOX2, KLF4, LIN28) and compared with methods that use C‐MYC. We demonstrate that CYCLIN D1 made iPSC have (a) lower multitelomeric signal, (b) reduced double‐strand DNA breaks, (c) correct nuclear localization of RAD51 protein expression, and (d) reduced single‐nucleotide polymorphism (SNP) changes per chromosome, compared with the classical reprogramming method using C‐MYC. CYCLIN D1 iPSC have reduced teratoma Ki67 cell growth kinetics and derived neural stem cells successfully engraft in a hostile spinal cord injury (SCI) microenvironment with efficient survival, differentiation. We demonstrate that CYCLIN D1 promotes double‐stranded DNA damage repair predominantly through HR during cell reprogramming to efficiently produce iPSC. CYCLIN D1 reduces general cell stress associated with significantly lower SIRT1 gene expression and can rescue Sirt1 null mouse cell reprogramming. In conclusion, we show synthetic mRNA transfection of CYCLIN D1 repairs DNA during reprogramming resulting in significantly improved genetically stable footprint in human iPSC, enabling a new cell reprogramming method for more accurate and reliable generation of human iPSC for disease modeling and future clinical applications.
Proposed clinical grade method to make better genetically stable human iPSC for clinical applications. CYCLIN D1 generated human iPSC have significantly improved genomic stability than current clinical grade methods that use C‐MYC, and thus clinically advantageous to reduce risk for long term cell replacement transplant strategies or accurate disease modeling.
Lithium (Li), valproate (VPA) and lamotrigine (LTG) are commonly used to treat bipolar disorder (BD). While their clinical efficacy is well established, the mechanisms of action at the molecular ...level are still incompletely understood. Here we investigated the molecular effects of Li, LTG and VPA treatment in induced pluripotent stem cell (iPSC)-derived neural precursor cells (NPCs) generated from 3 healthy controls (CTRL), 3 affective disorder Li responsive patients (Li-R) and 3 Li non-treated patients (Li-N) after 6 h and 1 week of exposure. Differential expression (DE) analysis after 6 h of treatment revealed a transcriptional signature that was associated with all three drugs and most significantly enriched for ribosome and oxidative phosphorylation (OXPHOS) pathways. In addition to the shared DE genes, we found that Li exposure was associated with 554 genes uniquely regulated in Li-R NPCs and enriched for spliceosome, OXPHOS and thermogenesis pathways. In-depth analysis of the treatment-associated transcripts uncovered a significant decrease in intron retention rate, suggesting that the beneficial influence of these drugs might partly be related to splicing. We examined the mitochondrial respiratory function of the NPCs by exploring the drugs' effects on oxygen consumption rate (OCR) and glycolytic rate (ECAR). Li improved OCR levels only in Li-R NPCs by enhancing maximal respiration and reserve capacity, while VPA enhanced maximal respiration and reserve capacity in Li-N NPCs. Overall, our findings further support the involvement of mitochondrial functions in the molecular mechanisms of mood stabilizers and suggest novel mechanisms related to the spliceosome, which warrant further investigation.
While neurodevelopmental abnormalities have been associated with schizophrenia (SCZ), the role of astroglia in disease pathophysiology remains poorly understood. In the present study, we used a human ...induced pluripotent stem cell (iPSC)-derived astrocyte model to investigate the temporal patterns of astroglia differentiation during developmental stages critical for SCZ using RNA sequencing. The model generated astrocyte-specific gene expression patterns during differentiation that corresponded well to astroglia-specific expression signatures of in vivo cortical fetal development. Using this model we identified SCZ-specific expression dynamics, and found that SCZ-associated differentially expressed genes were significantly enriched in the medial prefrontal cortex, striatum, and temporal lobe, targeting VWA5A and ADAMTS19. In addition, SCZ astrocytes displayed alterations in calcium signaling, and significantly decreased glutamate uptake and metalloproteinase activity relative to controls. These results implicate novel transcriptional dynamics in astrocyte differentiation in SCZ together with functional changes that are potentially important biological components of SCZ pathology.
Spinal cord injury (SCI) causes loss of neural functions below the level of the lesion due to interruption of spinal pathways and secondary neurodegenerative processes. The transplant of neural stem ...cells (NSCs) is a promising approach for the repair of SCI. Reprogramming of adult somatic cells into induced pluripotent stem cells (iPSCs) is expected to provide an autologous source of iPSC-derived NSCs, avoiding the immune response as well as ethical issues. However, there is still limited information on the behavior and differentiation pattern of transplanted iPSC-derived NSCs within the damaged spinal cord. We transplanted iPSC-derived NSCs, obtained from adult human somatic cells, into rats at 0 or 7 days after SCI, and evaluated motor-evoked potentials and locomotion of the animals. We histologically analyzed engraftment, proliferation, and differentiation of the iPSC-derived NSCs and the spared tissue in the spinal cords at 7, 21, and 63 days posttransplant. Both transplanted groups showed a late decline in functional recovery compared to vehicle-injected groups. Histological analysis showed proliferation of transplanted cells within the tissue and that cells formed a mass. At the final time point, most grafted cells differentiated to neural and astroglial lineages, but not into oligodendrocytes, while some grafted cells remained undifferentiated and proliferative. The proinflammatory tissue microenviroment of the injured spinal cord induced proliferation of the grafted cells and, therefore, there are possible risks associated with iPSC-derived NSC transplantation. New approaches are needed to promote and guide cell differentiation, as well as reduce their tumorigenicity once the cells are transplanted at the lesion site.
The electronics industry has one of the most complex global production chains in the international economy. Using data from the World Input–Output Database for the period 2000–14, this article traces ...individual contributions to the value chain in order to observe how financial turmoil has affected its evolution over time and to map international interactions. The authors point to a rise in offshoring until the outbreak of the global financial crisis of 2007–08, as China and other Eastern Asian economies became an essential node of value creation. They also detect a deep transformation of production technologies, accompanied by a process of upskilling.
Schizophrenia (SCZ) has a known neurodevelopmental etiology, but limited access to human prenatal brain tissue hampers the investigation of basic disease mechanisms in early brain development. Here, ...we elucidate the molecular mechanisms contributing to SCZ risk in a disease-relevant model of the prenatal human brain.
We generated induced pluripotent stem cell–derived organoids, termed human cortical spheroids (hCSs), from a large, genetically stratified sample of 14 SCZ cases and 14 age- and sex-matched controls. The hCSs were differentiated for 150 days, and comprehensive molecular characterization across 4 time points was carried out.
The transcriptional and cellular architecture of hCSs closely resembled that of fetal brain tissue at 10 to 24 postconception weeks, showing strongest spatial overlap with frontal regions of the cerebral cortex. A total of 3520 genes were differentially modulated between SCZ and control hCSs across organoid maturation, displaying a significant contribution of genetic loading, an overrepresentation of risk genes for autism spectrum disorder and SCZ, and the strongest enrichment for axonal processes in all hCS stages. The two axon guidance genes SEMA7A and SEMA5A, the first a promoter of synaptic functions and the second a repressor, were downregulated and upregulated, respectively, in SCZ hCSs. This expression pattern was confirmed at the protein level and replicated in a large postmortem sample.
Applying a disease-relevant model of the developing fetal brain, we identified consistent dysregulation of axonal genes as an early risk factor for SCZ, providing novel insights into the effects of genetic predisposition on the neurodevelopmental origins of the disorder.
Proteins targeted by the ubiquitin proteasome system (UPS) are identified for degradation by the proteasome, which has been implicated in the development of neurodegenerative diseases. Major ...histocompatibility complex (MHC) molecules present peptides broken down by the proteasome and are involved in neuronal plasticity, regulating the synapse number and axon regeneration in the central or peripheral nervous system during development and in brain diseases. The mechanisms governing these effects are mostly unknown, but evidence from different compartments of the cerebral cortex indicates the presence of immune-like MHC receptors in the central nervous system.
We used human induced pluripotent stem cells (iPSCs) differentiated into neural stem cells and then into motor neurons as a developmental model to better understand the structure of the proteasome in developing motor neurons. We performed a proteomic analysis of starting human skin fibroblasts, their matching iPSCs, differentiated neural stem cells and motor neurons that highlighted significant differences in the constitutive proteasome and immunoproteasome subunits during development toward motor neurons from iPSCs.
The proteomic analysis showed that the catalytic proteasome subunits expressed in fibroblasts differed from those in the neural stem cells and motor neurons. Western blot analysis confirmed the proteomic data, particularly the decreased expression of the β5i (PSMB8) subunit immunoproteasome in MNs compared to HFFs and increased β5 (PSMB5) in MNs compared to HFFs.
The constitutive proteasome subunits are upregulated in iPSCs and NSCs from HFFs. Immunoproteasome subunit β5i expression is higher in MNs than NSCs; however, overall, there is more of a constitutive proteasome structure in MNs when comparing HFFs to MNs. The proteasome composition may have implications for motor neuron development and neurodevelopmental diseases that warrant further investigation.
La fragmentación internacional de la producción es un elemento caracte-rístico de la profunda transformación experimentada por la economía mundial en las décadas recientes. Este proceso de creciente ...desintegración productiva está estrechamente relacionado con un cambio tecnológico digital que abre una nueva etapa de globalización económica. En este contexto, comprender las diferencias en las pautas distributivas y de especialización entre las econo-mías emergentes y las más avanzadas que participan en las cadenas globales de valor se convierte en objeto de estudio relevante.A partir de la información proporcionada por el proyecto WIOD se ha ana-lizado la evolución del valor añadido generado, el comportamiento de la pro-ductividad, la formación de capital y su impacto en el nivel y la estructura del empleo. Los resultados obtenidos nos muestran como la aceleración del pro-greso tecnológico ha inducido una sensible modificación de las tecnologías de producción, cambios de liderazgo en la capacidad de generación y retención de valor añadido, un protagonismo creciente de las rentas de capital y una asimetría en las oportunidades de empleo y la estructura salarial en función de la cualificación laboral
Schizophrenia (SCZ) and bipolar disorder (BIP) are severe mental disorders with a considerable disease burden worldwide due to early age of onset, chronicity, and lack of efficient treatments or ...prevention strategies. Whilst our current knowledge is that SCZ and BIP are highly heritable and share common pathophysiological mechanisms associated with cellular signaling, neurotransmission, energy metabolism, and neuroinflammation, the development of novel therapies has been hampered by the unavailability of appropriate models to identify novel targetable pathomechanisms. Recent data suggest that neuron-glia interactions are disturbed in SCZ and BIP, and are modulated by estrogen (E2). However, most of the knowledge we have so far on the neuromodulatory effects of E2 came from studies on animal models and human cell lines, and may not accurately reflect many processes occurring exclusively in the human brain. Thus, here we highlight the advantages of using induced pluripotent stem cell (iPSC) models to revisit studies of mechanisms underlying beneficial effects of E2 in human brain cells. A better understanding of these mechanisms opens the opportunity to identify putative targets of novel therapeutic agents for SCZ and BIP. In this review, we first summarize the literature on the molecular mechanisms involved in SCZ and BIP pathology and the beneficial effects of E2 on neuron-glia interactions. Then, we briefly present the most recent developments in the iPSC field, emphasizing the potential of using patient-derived iPSCs as more relevant models to study the effects of E2 on neuron-glia interactions.
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