Otx2 Expression Research Articles

Linking Maternal Sugar Consumption to Progenies’ Developmental Defects: A Focus on OTX2’s O‐GlcNAcylation

The O‐GlcNAc post‐translational modification is a dynamic and nutrient‐sensing modification that is reversibly added onto nuclear, cytoplasmic, and mitochondrial proteins. O‐GlcNAc is a unique glucose rheostat for cell signaling, since the level of extracellular glucose is reflected by the level of UDP‐GlcNAc, the primary substrate for O‐GlcNAcylation. To date, thousands of O‐GlcNAcylated proteins have been identified. Numerous physiological processes are O‐GlcNAc‐regulated such as cell cycle, transcriptional/translational regulation, protein localization and degradation. Moreover, O‐GlcNAc deregulation has been linked to pathologies like diabetes, cardiovascular diseases, neurodegeneration and cancers. O‐GlcNAcylated proteins are often involved in major signaling pathways, including those involved in development. Studying this modification therefore allows us to investigate the impact that glucose levels in the diet have in development, by regulating protein function in response to glucose concentration.Using cellular and mouse models, our lab has previously delved into the consequences of hyper‐O‐GlcNAcylation in the brain. Among phenotypes like early onset obesity and growth defects, the pituitary gland of these mice was generally smaller and corresponded with a developmental delay. In this study, we investigate the specific effects of hyper‐O‐GlcNAcylation in the pituitary gland by knocking out the O‐GlcNAcase (Oga), the enzyme that removes the O‐GlcNAc modification. We found that pituitary specific Oga KO mice had impaired eye development, growth defects, and inability to be metabolically self‐sufficient. A critical aspect of pituitary’s ontogeny is the local transient expression of the homeobox protein OTX2, which was identified as a major O‐GlcNAcylated protein in the developing brain, and interestingly, was dysregulated in our brain hyper‐O‐GlcNAcylated models. Using specific domain constructs, we have discovered that the Repression Domain of OTX2 is highly O‐GlcNAcylated, potentially affecting transcriptional activity and critical phosphorylation sites of this protein. To assess differential OTX2’s phosphorylation upon hyper‐O‐GlcNAcylation in vitro, we treated HeLa cells with the OGA inhibitor Thiamet‐G. After immunoprecipitation, OTX2’s phosphorylation was assessed using a Phos‐tag gel, delaying specifically the migration of the phosphorylated protein. Surprisingly, we did not observe a significant difference in OTX2 phosphorylation with O‐GlcNAc fluctuation. This suggested that OTX2’s O‐GlcNAcylation does not compete with phosphorylation sites and rather regulates OTX2’s activity or localization.To summarize, this study highlights the O‐GlcNAc modification as a nutrient‐dependent sensor that regulates the homeobox protein OTX2 during pituitary and brain development. Like many homeobox proteins, OTX2 level needs to be tightly regulated for proper patterning and development, and its deregulation amongst other proteins is a major driver of Medulloblastoma. Therefore, we also foresee that O‐GlcNAcylated OTX2 may play a major role in Medulloblastoma development.Support or Funding InformationNICHD R00HD087430

Homeoprotein OTX1 and OTX2 involvement in rat myenteric neuron adaptation after DNBS-induced colitis.

BackgroundInflammatory bowel diseases are associated with remodeling of neuronal circuitries within the enteric nervous system, occurring also at sites distant from the acute site of inflammation and underlying disturbed intestinal functions. Homeoproteins orthodenticle OTX1 and OTX2 are neuronal transcription factors participating to adaptation during inflammation and underlying tumor growth both in the central nervous system and in the periphery. In this study, we evaluated OTX1 and OTX2 expression in the rat small intestine and distal colon myenteric plexus after intrarectal dinitro-benzene sulfonic (DNBS) acid-induced colitis.MethodsOTX1 and OTX2 distribution was immunohistochemically investigated in longitudinal muscle myenteric plexus (LMMP)-whole mount preparations. mRNAs and protein levels of both OTX1 and OTX2 were evaluated by qRT-PCR and Western blotting in LMMPs.ResultsDNBS-treatment induced major gross morphology and histological alterations in the distal colon, while the number of myenteric neurons was significantly reduced both in the small intestine and colon. mRNA levels of the inflammatory markers, TNFα, pro-IL1β, IL6, HIF1α and VEGFα and myeloperoxidase activity raised in both regions. In both small intestine and colon, an anti-OTX1 antibody labeled a small percentage of myenteric neurons, and prevalently enteric glial cells, as evidenced by co-staining with the glial marker S100β. OTX2 immunoreactivity was present only in myenteric neurons and was highly co-localized with neuronal nitric oxide synthase. Both in the small intestine and distal colon, the number of OTX1- and OTX2-immunoreactive myenteric neurons significantly increased after DNBS treatment. In these conditions, OTX1 immunostaining was highly superimposable with inducible nitric oxide synthase in both regions. OTX1 and OTX2 mRNA and protein levels significantly enhanced in LMMP preparations of both regions after DNBS treatment.ConclusionsThese data suggest that colitis up-regulates OTX1 and OTX2 in myenteric plexus both on site and distantly from the injury, potentially participating to inflammatory-related myenteric ganglia remodeling processes involving nitrergic transmission.

Functional and Evolutionary Diversification of Otx2 and Crx in Vertebrate Retinal Photoreceptor and Bipolar Cell Development

Otx family homeoproteins Otx2 and Crx are expressed in photoreceptor precursor cells and bind to the common DNA-binding consensus sequence, but these two proteins have distinct functions in retinal development. To examine the functional substitutability of Otx2 and Crx, we generate knockin mouse lines in which Crx is replaced by Otx2 and vice versa. We find that Otx2 and Crx cannot be substituted in photoreceptor development. Subsequently, we investigate the function of Otx2 in photoreceptor and bipolar cell development. High Otx2 levels induce photoreceptor cell fate but not bipolar cell fate, whereas reduced Otx2 expression impairs bipolar cell maturation and survival. Furthermore, we identify Otx2 and Crx in the lamprey genome by using synteny analysis, suggesting that the last common ancestor of vertebrates possesses both Otx2 and Crx. We find that the retinal Otx2 expression pattern is different between lampreys and mice, suggesting that neofunctionalization of Otx2 occurred in the jawed vertebrate lineage.

A distal enhancer that directs Otx2 expression in the retinal pigment epithelium and neuroretina.

Homeodomain transcription factor Otx2 is essential for embryonic development of multiple head tissues, including retinal pigment epithelium (RPE) and neuroretina. Temporospatial regulation of Otx2 expression is critical for its functions. Molecular dissection of the cis-acting enhancers will help elucidate how Otx2 expression is regulated. We comprehensively characterized distal enhancer hs1150 that was previously identified in a high throughput study. We established multiple transgenic mouse lines in which human hs1150, corresponding mouse hs1150, and two highly conserved sub-fragments in the mouse hs1150 were individually fused to a minimal hsp68 promoter to drive reporter expression. We found that hs1150 enhancer directed reporter expression in the RPE, neuroretina, and brain in a developmentally regulated manner. Human hs1150-directed reporter expression largely recapitulated Otx2 expression in the RPE, in the early neuroretina, and to a lesser degree in the early brain. Mouse hs1150, although shorter than human hs1150, exhibited similar enhancer activity, indicating functional conservation of hs1150 enhancer across species. Both of the highly conserved subfragments in mouse hs1150 enhancer directed reporter expression in the early neuroretina, indicating that the hs1150 enhancer has two functional components. Our findings provide insight into the molecular mechanisms underlying the regulation of Otx2 retinal expression.

PDTM-28. AN OTX2-PAX3 SIGNALLING AXIS REGULATES GROUP 3 MEDULLOBLASTOMA CELL FATE

Abstract The majority of Group 3 medulloblastomas (MB) exhibit amplification or increased expression of OTX2. OTX2 is primarily known as an oncogenic driver of tumor growth and cell cycle progression in Group 3 MB; however, its role as a repressor of differentiation is poorly characterized. Therefore, we utilized extensive patient data and mapped Group 3 MB chromatin dynamics in stem cell-enriched cultures to evaluate the divergent role of OTX2 in cell fate decisions in Group 3 MB pathogenesis. Several PAX genes were identified as novel OTX2 targets in Group 3 MB. Examination of patient data revealed that PAX3 and PAX6 expression is significantly reduced in Group 3 MB patients and is associated with significantly reduced survival. Functional evaluation of PAX3 and PAX6 expression showed that PAX3 expression significantly reduced self-renewal capacity of Group 3 MB tumorspheres in vitro and significantly prolonged survival and reduced tumor size in orthotopic xenograft models in vivo. RNA-sequencing of PAX3 and PAX6 gain of function (GOF) tumorspheres revealed mTORC1 signalling was specifically downregulated in PAX3 GOF, indicating this pathway may be critical for the survival and self-renewal differences observed between PAX3/PAX6 GOF models. Treatment of Group 3 MB with mTOR inhibitors reduced self-renewal in vitro and significantly prolonged survival and reduced tumor size in vivo. To further evaluate the role for this signalling axis in the Group 3 MB neural lineage hierarchy, we carried out scRNA-sequencing in tumorspheres from 4 Group 3 MB cell lines. Interestingly, a broad range of OTX2 expression was observed across single cell clusters, suggesting distinct OTX2 regulatory hierarchies are present in Group 3 MB. Collectively, our work demonstrates the multifaceted role of OTX2 as a regulator of cell fate decisions in Group 3 MB and identifies a novel role for mTORC1 signalling in Group 3 MB self-renewal and differentiation.

Application of Hanging Drop Culture for Retinal Precursor-Like Cells Differentiation of Human Adipose-Derived Stem Cells Using Small Molecules

Retinal degenerative diseases lead to blindness due to poorly regenerative potential of the retina. Recently, cell therapy is more considered for degenerative diseases. Autologous mesenchymal stem cells derived from adipose tissue are a suitable source for this purpose. Therefore, we conducted a stepwise efficient method to differentiate human adipose-derived stem cells (hADSCs) into retinal precursor-like cells in vitro. We compared two differentiation protocols, monolayer and hanging drop cultures. Through the defined medium and 3D hanging drop culture method, we could achieve up to 75% retinal precursor gene expression profile (PAX6, RAX, CHX10, and CRX) from hADSCs. By imitation of in vivo development, for direct conversion of stem cells into retinal cells, the suppression of the BMP, Nodal, and Wnt signaling pathways was carried out by using three small molecules. The hADSCs were primarily differentiated into anterior neuroectodermal cells by expression of OTX2, SIX3, and Β-TUB III and then the differentiated cells were propelled into the retinal cells. According to our data from real-time PCR, RT-PCR, immunocytochemistry, and functional assay, it seems that the hanging drop method improved retinal precursor differentiation yield which these precursor-like cells respond to glutamate neurotransmitter. Regarding the easy accessibility and immunosuppressive properties of hADSCs and more efficient hanging drop method, this study may be useful for future autologous cell therapy of retinal degenerative disorders.

Identification of a 5-Gene Signature Predicting Progression and Prognosis of Clear Cell Renal Cell Carcinoma.

BackgroundAlthough the mortality rates of clear cell renal cell carcinoma (ccRCC) have decreased in recent years, the clinical outcome remains highly dependent on the individual patient. Therefore, identifying novel biomarkers for ccRCC patients is crucial.Material/MethodsIn this study, we obtained RNA sequencing data and clinical information from the TCGA database. Subsequently, we performed integrated bioinformatic analysis that includes differently expressed genes analysis, gene ontology and KEGG pathway analysis, protein-protein interaction analysis, and survival analysis. Moreover, univariate and multivariate Cox proportional hazards regression models were constructed.ResultsAs a result, we identified a total of 263 dysregulated genes that may participate in the metastasis of ccRCC, and established a predictive signature relying on the expression of OTX1, MATN4, PI3, ERVV-2, and NFE4, which could serve as significant progressive and prognostic biomarkers for ccRCC.ConclusionsWe identified differentially expressed genes that may be involved in the metastasis of ccRCC. Moreover, a predictive signature based on the expression of OTX1, MATN4, PI3, ERVV-2, and NFE4 could be an independent prognostic factor for ccRCC.

Expression of OTX1 and OTX2 in Normal and Patho-logic Conditions of The Nasal Cavity

Homeobox genes are a family of regulatory genes coding for transcription factors, that function as marker of specific brain areas and of nuclei of the developing central nervous system [1].

SUN-470 The Homeodomain Transcription Factors Six3 and OTX2 Act on Mouse and Human Kisspeptin Promoters to Repress Transcription

Idiopathic hypogonadotropic hypogonadism (IHH) is a gonadotropin-releasing hormone (GnRH) deficiency disorder that, in a subset of individuals, can occur alongside anosmia (Kallmann Syndrome). Known genetic causes for these disorders account for only 45% of affected individuals, leaving the majority of unknown origin. In mice, the homeodomain transcription factors Six3 and OTX2 are necessary for a normal number of GnRH neurons, GnRH neuron migration, and/or GnRH mRNA levels. The loss of just a single allele results in subfertility, hypogonadism, and/or anosmia, making them promising candidates for dysregulation in IHH and Kallman Syndrome. Previous work has shown the importance of these factors within GnRH neurons, but little is known about their roles in upstream cell types, such as kisspeptin neurons. Using qPCR and RNA-seq we have verified that Six3 and OTX2 are present in both an arcuate population (KTaR) and AVPV population (KTaV) of immortalized kisspeptin neurons. This led us to hypothesize that Six3 and OTX2 are critical regulators of kisspeptin gene transcription. To test this hypothesis we performed transient transfections in KTaR and KTaV cell lines with Six3 and OTX2 expression vectors along with either a mouse or human kisspeptin luciferase reporter. We found that in both populations, Six3 repressed both mouse (p < 0.05) and human (p < 0.01) kisspeptin transcription. We also found that OTX2 repressed both mouse and human kisspeptin transcription in the KTaV cell line (p < 0.05), but did not alter transcription in the KTaR cell line. These results suggest that Six3 and OTX2 can regulate the kisspeptin promoter in vitro and produce a response that is consistent between both mouse and human promoters. Effects of Six3 are similar between kisspeptin populations, while OTX2 may function in a population-specific manner.

Homeobox genes in melatonin-producing pinealocytes: Otx2 and Crx act to promote hormone synthesis in the mature rat pineal gland.

Homeobox genes encode transcription factors that regulate developmental processes; however, in the pineal gland, a neuroendocrine organ responsible for nocturnal melatonin synthesis, expression of the homeobox genes Otx2 (orthodenticle homeobox 2) and Crx (cone-rod homeobox) persists postnatally. We here show that OTX2 and CRX are exclusively present in melatonin-producing pinealocytes of the rat pineal gland. To understand the roles of Otx2 and Crx in the mature pineal gland, we used siRNA technology in cultured rat pinealocytes with the nocturnal situation mimicked by adding norepinephrine to the culture media. siRNA-induced knockdown of Otx2 was found to reduce expression levels of the enzymes involved in melatonin synthesis at both transcript and protein levels. Similar results were obtained when knocking down Crx. Knocking down Otx2 and Crx simultaneously produced an even larger reduction in both transcript and protein levels of the melatonin-producing enzymes and also reduced the levels of melatonin released to the culture media. These results suggest that Otx2 and Crx, both alone and in combination, act to control pineal melatonin synthesis.

Identification of a promoter element mediating kisspeptin-induced increases in GnRH gene expression in sheep

Gonadotropin-releasing hormone (GnRH) plays an important role in regulating the activities of other components downstream of the hypothalamic-pituitary-gonadal (HPG) axis and maintaining the normal reproductive cycle of animals. However, the molecular mechanisms by which GnRH synthesis and secretion are regulated in sheep remains unclear. In this study, a series of eight recombinant vectors with deletion fragments were constructed and cotransfected with pGL3-Basic and pRL-SV40 into sheep hypothalamic neuronal cells. After treatment with 1 nM kisspeptin, the core promoter of the sheep GnRH gene was identified to be in the region of −1912 bp to −1461 bp by dual-luciferase reporter assay. Bioinformatics analysis showed that there was a binding site for the transcription factor Otx-2 in the core promoter region (−1786 to −1770 bp) that was highly conserved among different species. The expression patterns of Kiss-1, Otx-2 and GnRH in the sheep hypothalamus were the same, and the expression of Kiss-1, Otx-2 and GnRH was significantly higher in the breeding season than in nonbreeding season (P < 0.01). In addition, when hypothalamic neurons were cultured in vitro with kisspeptin, kisspeptin induced the expression of GnRH and Otx-2. In conclusion, these results provide evidence that the core promoter region (−1786 to −1770 bp) of the GnRH gene is involved in the regulation of hypothalamic activity by kisspeptin and that binding of the transcription factor Otx-2 mediates this activation.

Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas.

OTX homeobox (HB) genes are expressed during embryonic morphogenesis and during the development of olfactory epithelium in adult organisms. Mutations occurring in these genes are often related to tumorigenesis in human. No data are available today regarding the possible correlation between OTX genes and tumors of the nasal cavity. The aim of this work is to understand if OTX1 and OTX2 can be considered as molecular markers in the development of nasal tumors. We selected nasal and sinonasal adenocarcinomas to investigate the expression of OTX1 and OTX2 genes through immunohistochemical and real-time PCR analyses.Both OTX1 and OTX2 were absent in all the samples of sinonasal Intestinal-Type Adenocarcinomas (ITACs). OTX1 mRNA was identified only in Non-Intestinal Type Adenocarcinomas (NITACs) while OTX2 mRNA was expressed only in Olfactory Neuroblastomas (ONs). We have demonstrated that the differential gene expression for both OTX1 and OTX2 genes might be a useful molecular marker to distinguish the different types of sinonasal tumors.

Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas

OTX homeobox (HB) genes are expressed during embryonic morphogenesis and during the development of olfactory epithelium in adult organisms. Mutations occurring in these genes are often related to tumorigenesis in human. No data are available today regarding the possible correlation between OTX genes and tumors of the nasal cavity. The aim of this work is to understand if OTX1 and OTX2 can be considered as molecular markers in the development of nasal tumors. We selected nasal and sinonasal adenocarcinomas to investigate the expression of OTX1 and OTX2 genes through immunohistochemical and real-time PCR analyses.Both OTX1 and OTX2 were absent in all the samples of sinonasal Intestinal-Type Adenocarcinomas (ITACs). OTX1 mRNA was identified only in Non-Intestinal Type Adenocarcinomas (NITACs) while OTX2 mRNA was expressed only in Olfactory Neuroblastomas (ONs). We have demonstrated that the differential gene expression for both OTX1 and OTX2 genes might be a useful molecular marker to distinguish the different types of sinonasal tumors.

OTX1 and OTX2 Genes in Medulloblastoma

To study the prevalence of OTX1 and OTX2 gene expression in 60 medulloblastoma specimen samples and to establish correlations between gene expression and clinical and histopathological aspects. We performed a retrospective analysis of 60 patients with a diagnosis of medulloblastoma at the Clinicas Hospital of the School of Medicine, University of São Paulo, and the Cancer Hospital of Barretos. We created a database of the 60 patients containing information on the gene expression of OTX1 and OTX2 (obtained using real-time polymerase chain reaction) and clinical and epidemiological data. Statistical tests were performed to verify potential correlations of clinicopathological data and follow-up aspects with gene expression. The OTX1 gene was expressed in 52% of the study population. Expression varied with age (higher in adults), location (predominantly by hemisphere), and histological type (desmoplastic). The OTX2 gene was expressed in 62% of the study population. Expression varied with age (higher in younger age groups), location (predominantly vermis), and histological type (classic and anaplastic). A statistical correlation between OTX2 gene expression and the development of leptomeningeal metastases was observed. The relative expression of OTX1 and OTX2 was dependent on patient age, tumor location, and histological variant. In addition, OTX2 expression might be a predictive factor for leptomeningeal metastases of medulloblastoma. The OTX pathway should be consider as an important venue for medulloblastomas development.

Ameliorating effect of postweaning exposure to antioxidant on disruption of hippocampal neurogenesis induced by developmental hypothyroidism in rats.

Developmental hypothyroidism as a model of autism spectrum disorders disrupts hippocampal neurogenesis through the adult stage. The present study investigated the ameliorating effect of postweaning exposure to antioxidant on the hypothyroidism-induced disruptive neurogenesis. Mated female Sprague-Dawley rats were treated with 0 or 10 ppm 6-propyl-2-thiouracil (PTU) as an anti-thyroid agent in drinking water from gestational day 6 to postnatal day (PND) 21 on weaning. PTU-exposed male offspring were fed either basal diet, diet containing α-glycosyl isoquercitrin (AGIQ) at 5,000 ppm or α-lipoic acid (ALA) at 1,000 ppm as an antioxidant from PND 21 to PND 77. PTU-exposure decreased DCX+ and NeuN+ granule cell lineage subpopulations, synaptic plasticity-related FOS+ granule cells, and hilar PVALB+ and GAD67+ GABAergic interneurons, increased hilar SST+ and CALB2+ interneurons, and upregulated Gria3, Otx2, and antioxidant enzyme genes in the dentate gyrus on PND 77. These results suggest disruption of neurogenesis remained in relation with increase of oxidative stress and compensatory responses to the disruption at the adult stage. AGIQ recovered expression of some antioxidant enzyme genes and was effective for restoration of NeuN+ postmitotic granule cells and PVALB+ and SST+ interneurons. In contrast, ALA was effective for restoration of all interneuron subpopulations, as well as postmitotic granule cells, and upregulated Grin2a that may play a role for the restoration. Both antioxidants recovered expression of Otx2 and AGIQ-alone recovered Gria3, suggesting a reversal of disruptive neurogenesis by compensatory responses. Thus, postweaning antioxidant exposure may be effective for ameliorating developmental hypothyroidism-induced disruptive neurogenesis by restoring the function of regulatory system.

Ultraviolet B-induced Otx2 expression in lens epithelial cells promotes epithelial-mesenchymal transition.

ABSTRACTUltraviolet (UV) radiation of eyes is a major risk factor for cataractogenesis, although the molecular mechanisms underlying this process remain poorly understood and genes that are affected by UV radiation have not been fully identified. In this study, we examined the UV-related gene regulation in lens epithelial cells (LECs) of mouse eyes and investigated the molecular mechanisms of UV-triggered cataractogenesis. Forty-one genes were significantly upregulated in LECs following UVB exposure in vivo in two independent experiments. Among these, Otx2 was strongly upregulated in LECs, suggesting that it may act as an upstream regulator of UVB-induced changes in gene expression. Accordingly, Otx2 overexpression in LECs in vitro induced morphological changes in cell shapes. Epithelial–mesenchymal transition (EMT)-related molecules, such as TGFβ2, αSMA and fibronectin were upregulated in Otx2-overexpressing LECs, concomitant with suppression of lens fiber cell marker genes, such as CRYAA and DNASEIIB. In vitro experiments suggested that UVB upregulated Otx2 through hydrogen peroxide generation. Aberrant upregulation of Otx2 in LECs following UV irradiation induces the EMT and alteration of the lens cell characteristics, likely contributing to cataractogenesis.

Molecular network of miR-1343 regulates the pluripotency of porcine pluripotent stem cells via repressing OTX2 expression

ABSTRACTPorcine OTX2 was found to be highly activated in porcine iPS cells (piPSCs) that were reported by different laboratories worldwide. To reveal the regulatory function of OTX2 in porcine reprogrammed cells, we screened porcine miRNA-seq databases and found two miRNAs, miR-1343 and miR-545, that could specifically bind to 3ʹUTR of OTX2 and suppress endogenous OTX2 expression in piPSCs. Knockdown of OTX2 by miR-1343 and miR-545 could significantly increase the expression of SOX2 and ESRRB, but did not alter the expressions of OCT4 and KLF4, and improve the pluripotency of piPSCs. The promoter-based assays showed that OTX2 potentially bound to the promoter region of SOX2 and ESRRB and suppressed their expression. On the other hand, SOX2 could interact with OTX2 promoter. Ectopic expression of SOX2 could significantly decrease OTX2 promoter activity, showing that there is a negative feedback loop between SOX2 and OTX2. Additionally, SOX2 and ESRRB significantly stimulated miR-1343 expression in piPSCs, but OTX2 down regulated the expression of miR-1343 in either direct or indirect manners. In summary, this study demonstrates that there is a regulatory network mediated by miR-1343, in which downregulation of OTX2 by miR-1343 can elevate the expression of pluripotent genes that were then sustain the pluripotency of piPSCs.

Fast Generation of Functional Subtype Astrocytes from Human Pluripotent Stem Cells.

SummaryDifferentiation of astrocytes from human pluripotent stem cells (hPSCs) is a tedious and variable process. This hampers the study of hPSC-generated astrocytes in disease processes and drug development. By using CRISPR/Cas9-mediated inducible expression of NFIA or NFIA plus SOX9 in hPSCs, we developed a method to efficiently generate astrocytes in 4–7 weeks. The astrocytic identity of the induced cells was verified by their characteristic molecular and functional properties as well as after transplantation. Furthermore, we developed a strategy to generate region-specific astrocyte subtypes by combining differentiation of regional progenitors and transgenic induction of astrocytes. This simple and efficient method offers a new opportunity to study the fundamental biology of human astrocytes and their roles in disease processes.

Differentiation of eye field neuroectoderm from human adipose-derived stem cells by using small-molecules and hADSC-conditioned medium

Recently, stem-cell therapy as a promising therapeutic alternative is considered to treat retinal degenerative diseases. Here, we used small molecules and concentrated conditioned medium selectively enriched with Amicon filter units from human adipose-derived stem cells (hADSC-CM) containing various neurotrophic factors to induce hADSCs toward eye field neuroectoderm (EFN). For induction of stem cells, hADSC-CM and small molecules CKI-7, SB431542 and LDN193189 as inhibitors of Wnt, Nodal and BMP4 signaling pathways were used, respectively. We found the highest expression of β-TUB III as a neural marker in the group in which small molecules and conditioned medium were applied simultaneously. Moreover, EFN markers SIX3, PAX6 and RAX had higher expression in the presence of a conditioned medium. However, the superior expression of ENF marker OTX2 was seen in the small molecules group. Our results indicated that neurotrophic factors present in hADSCs-CM could induce hADSCs into EFN cells. Therefore, a more thorough study of these factors and their effects in hADSC-CM might pave the way for cellular and non-cellular therapy in retinal degenerative diseases.

Patterning factors during neural progenitor induction determine regional identity and differentiation potential in vitro

The neural tube consists of neural progenitors (NPs) that acquire different characteristics during gestation due to patterning factors. However, the influence of such patterning factors on human pluripotent stem cells (hPSCs) during in vitro neural differentiation is often unclear. This study compared neural induction protocols involving in vitro patterning with single SMAD inhibition (SSI), retinoic acid (RA) administration and dual SMAD inhibition (DSI). While the derived NP cells expressed known NP markers, they differed in their NP expression profile and differentiation potential. Cortical neuronal cells generated from 1) SSI NPs exhibited less mature neuronal phenotypes, 2) RA NPs exhibited an increased GABAergic phenotype, and 3) DSI NPs exhibited greater expression of glutamatergic lineage markers. Further, although all NPs generated astrocytes, astrocytes derived from the RA-induced NPs had the highest GFAP expression. Differences between NP populations included differential expression of regional identity markers HOXB4, LBX1, OTX1 and GSX2, which persisted into mature neural cell stages. This study suggests that patterning factors regulate how potential NPs may differentiate into specific neuronal and glial cell types in vitro. This challenges the utility of generic neural induction procedures, while highlighting the importance of carefully selecting specific NP protocols.