scholarly journals Equilin does not affect thyroid hormone signaling in the developing Xenopus laevis tadpole brain

2019 ◽  
Author(s):  
Robert G. Bass ◽  
Zahabiya Husain ◽  
Lara Dahora ◽  
Christopher K. Thompson
Keyword(s):  
Thyroid Hormone ◽  
Xenopus Laevis ◽  
Progenitor Cells ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Research Effort ◽  
Dependent Manner ◽  
Dividing Cells ◽  
Hormone Sensitive ◽  
Hormone Control

AbstractToxcast/Tox21 is a massive federally run research effort dedicated to better understanding the potential toxicity of thousands of compounds in a high throughput manner. Among this list of compounds is equilin, an estrogen-like compound that was flagged as a potential thyroid hormone agonist. Here we examine if equilin acts like a thyroid hormone agonist on cellular and molecular mechanisms of brain development in Xenopus laevis tadpoles. To examine the effect of equilin, tadpoles were divided into eight groups and received 4 days of exposure. The experimental groups were as follows: 1 μL, 10 μL, and 100 μL of equilin, 1 μL, 10μM, and 100 μM of 17-β estradiol as an estrogen control, 15 μg/mL thyroxine (T4) as a thyroid hormone control, and a no-exposure control. After 4 days of treatment, animals were treated with CldU to label dividing cells for 2hr and then euthanized in MS-222. After fixation, body length was measured and the brains dissected out. IHC was performed on brains for CldU to label proliferating neural progenitor cells. Brains were then whole-mounted and analyzed using confocal microscopy. We found that equilin did not increase the number of dividing progenitor cells in a T4-like manner. Instead, equilin decreased proliferation in a dose-dependent manner, as did estradiol. The same paradigm was performed separately staining for caspase-3 and h2ax, finding that equilin increased cell death in contrast to CNTL and T4. In another experiment, RNA was extracted from tadpole brains in each group and qPCR was performed to assess change in expression of thyroid hormone-sensitive genes, Equilin did not affect gene expression in a thyroid hormone-like manner. Our data indicate that equilin does not act as a thyroid hormone agonist in the Xenopus laevis nervous system but instead acts similarly to estradiol. Our data strongly suggest that equilin is not a TH disruptor, contrary to the findings of the ToxCast/Tox21 dataset.

scholarly journals Myelin basic protein enhances axonal regeneration from neural progenitor cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhengjian Yan ◽  
Lei Chu ◽  
Xiaojiong Jia ◽  
Lu Lin ◽  
Si Cheng
Keyword(s):  
Myelin Basic Protein ◽  
Neurite Outgrowth ◽  
Progenitor Cells ◽  
Axonal Regeneration ◽  
Neural Progenitor Cells ◽  
Basic Protein ◽  
Neural Progenitor ◽  
Dependent Manner ◽  
Cord Injury

Abstract Introduction Stem cell therapy using neural progenitor cells (NPCs) shows promise in mitigating the debilitating effects of spinal cord injury (SCI). Notably, myelin stimulates axonal regeneration from mammalian NPCs. This led us to hypothesize that myelin-associated proteins may contribute to axonal regeneration from NPCs. Methods We conducted an R-based bioinformatics analysis to identify key gene(s) that may participate in myelin-associated axonal regeneration from murine NPCs, which identified the serine protease myelin basic protein (Mbp). We employed E12 murine NPCs, E14 rat NPCs, and human iPSC-derived Day 1 NPCs (D1 hNPCs) with or without CRISPR/Cas9-mediated Mbp knockout in combination with rescue L1-70 overexpression, constitutively-active VP16-PPARγ2, or the PPARγ agonist ciglitazone. A murine dorsal column crush model of SCI utilizing porous collagen-based scaffolding (PCS)-seeded murine NPCs with or without stable Mbp overexpression was used to assess locomotive recovery and axonal regeneration in vivo. Results Myelin promotes axonal outgrowth from NPCs in an Mbp-dependent manner and that Mbp’s stimulatory effects on NPC neurite outgrowth are mediated by Mbp’s production of L1-70. Furthermore, we determined that Mbp/L1-70’s stimulatory effects on NPC neurite outgrowth are mediated by PPARγ-based repression of neuron differentiation-associated gene expression and PPARγ-based Erk1/2 activation. In vivo, PCS-seeded murine NPCs stably overexpressing Mbp significantly enhanced locomotive recovery and axonal regeneration in post-SCI mice. Conclusions We discovered that Mbp supports axonal regeneration from mammalian NPCs through the novel Mbp/L1cam/Pparγ signaling pathway. This study suggests that bioengineered, NPC-based interventions can promote axonal regeneration and functional recovery post-SCI.

Abstract 1451: Hyperpolarization Induces Differentiation Of Human Cardiomyocyte Progenitor Cells

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Piet van Vliet ◽  
Teun P de Boer ◽  
Marcel A van der Heyden ◽  
Joost P Sluijter ◽  
Pieter A Doevendans ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Molecular Mechanisms ◽  
Troponin I ◽  
Lucifer Yellow ◽  
Myogenic Differentiation ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Cardiomyogenic Differentiation ◽  
Low Potassium ◽  
Calcineurin Signaling

Background: Recently, we have isolated cardiomyocyte progenitor cells (hCMPCs) from human fetal and adult hearts. These cells differentiate into spontaneously beating cardiomyocytes when stimulated with 5-azacytidine. Subsequent stimulation by TGFβ enhances differentiation efficiency to nearly 100%. The underlying molecular mechanisms mediating this cardiomyogenic differentiation are not understood. In skeletal myoblasts, hyperpolarization-mediated activation of calcineurin signaling is crucial for myogenic differentiation. In hCMPCs, whole-cell patch clamp recordings showed a hyperpolarized membrane potential after stimulation with TGFβ or BMP. We hypothesized that hyperpolarization and calcineurin signaling regulate cardiomyogenic differentiation of hCMPCs after TGFβ stimulation. Methods & Results: To test whether hyperpolarization initiates cardiomyogenic differentiation, hyperpolarization was induced by 1) co-culture of hCMPCs with HEK 293 cells overexpressing a Kir2.1GFP fusion protein (KWGF cells) or 2) culture of hCMPCs overnight in medium containing low potassium concentrations. During co-culture, Lucifer Yellow dye injection in KWGF cells spread to neighboring hCMPCs, indicating cellular coupling. This resulted in stable hyperpolarization in hCMPCs, which could be blocked by addition of the gap junction inhibitor halothane. After two weeks, qPCR analysis revealed increased expression of cardiac sarcomeric genes in the hCMPCs in a dose-dependent manner. Induction of hyperpolarization by culturing hCMPCs with low potassium concentrations also resulted in increased expression of cardiac genes and the formation of spontaneously beating cells. Immunofluorescence staining revealed striated patterns of troponin I and α-actinin. Interestingly, hyperpolarization also increased intracellular calcium levels in hCMPCs, as measured by ratiometric imaging of indo-1 fluorescence, and, subsequently, a time-dependent increase in NFAT-Luciferase reporter activity, indicating activation of the calcineurin pathway. Conclusion: TGFβ and/or BMP-mediated hyperpolarization of hCMPCs induces calcineurin-mediated cardiomyogenic differentiation.

Abstract W MP86: Microrna-146a Modulates Neurogenesis And Oligodendrogenesis After Stroke

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Xianshuang Liu ◽  
Chopp Michael ◽  
Xinli Wang ◽  
Li Zhang ◽  
Yisheng Cui ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Target Genes ◽  
Artery Occlusion ◽  
Locked Nucleic Acid ◽  
Myelin Proteins ◽  
Oligodendrocyte Progenitor Cells ◽  
Marker Proteins

Background: Neurogenesis and oligodendrogenesis are associated with functional recovery after stroke. However, the molecules that regulate the generation of new neurons and oligodendrocytes have not been fully investigated. MicroRNAs (miRNAs) post-transcriptionally regulate gene expression. MiR-146a has been reported to regulate the immune response in cells, but the role of miR-146a in neural (NPCs) and oligodendrocyte progenitor cells (OPCs) remains unexplored. Methods and Results: Adult Wistar rats were subjected to right middle cerebral artery occlusion (MCAo). In situ hybridization using locked nucleic acid (LNA)probes against miR-146a showed that stroke considerably increased miR-146a density in the subventricular zone (SVZ, 19 ± 1 vs 6 ± 0.1 area/mm2 in non-MCAo group, p<0.05, n=4/group) and corpus callosum (24 ± 3 vs 8±1 area/mm2 in non-MCAo group) of the ischemic hemisphere. Quantitative RT-PCR also demonstrated a marked upregulation of miR-146a transcript in ischemic NPCs (8.5 fold), suggesting an important role in stroke-induced neurogenesis and oligodendrogenesis. To test its biological function, we over-expressed miR-146a in neural progenitor cells by transfection of miR-146a mimics using nucleofector and found that elevation of miR-146a significantly increased the percentage of Tuj1+ neuroblasts (5 ± 0.3 vs 1 ± 0.2%, p<0.05, n=6/group) and O4+ OPCs (10 ± 1 vs 4 ± 0.4%, p<0.05). Moreover, over-expression of miR-146a in primary cultured OPCs significantly increased several myelin proteins including MBP and PLP, and decreased levels of OPC marker proteins including PDGFRα and NG2, whereas attenuation of miR-146a by siRNA against miR-146a suppressed myelin proteins and augmented OPC marker proteins. Furthermore, miR-146a levels in the OPCs were inversely related to IRAK1 proteins, one of miR-146a target genes. Attenuation of IRAK1 in OPCs substantially increased myelin proteins, indicating that miR-146a mediates oligodendrocyte maturation via targeting IRAK1. Conclusion: Our data provide new insight into molecular mechanisms underlying stroke-induced neurogenesis and oligodendrogenesis by revealing a novel role of miR-146a in NPCs and OPCs, which has potential to be used as a new therapy for neurorecovery after stroke.

scholarly journals NCAM regulates temporal specification of neural progenitor cells via profilin2 during corticogenesis

2019 ◽  
Vol 219 (1) ◽  
Author(s):  
Rui Huang ◽  
De-Juan Yuan ◽  
Shao Li ◽  
Xue-Song Liang ◽  
Yue Gao ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Cortical Neurons ◽  
Actin Polymerization ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Cortical Development ◽  
Neural Progenitor ◽  
Neural Cell Adhesion ◽  
Fate Decision ◽  
Temporal Specification

The development of cerebral cortex requires spatially and temporally orchestrated proliferation, migration, and differentiation of neural progenitor cells (NPCs). The molecular mechanisms underlying cortical development are, however, not fully understood. The neural cell adhesion molecule (NCAM) has been suggested to play a role in corticogenesis. Here we show that NCAM is dynamically expressed in the developing cortex. NCAM expression in NPCs is highest in the neurogenic period and declines during the gliogenic period. In mice bearing an NPC-specific NCAM deletion, proliferation of NPCs is reduced, and production of cortical neurons is delayed, while formation of cortical glia is advanced. Mechanistically, NCAM enhances actin polymerization in NPCs by interacting with actin-associated protein profilin2. NCAM-dependent regulation of NPCs is blocked by mutations in the profilin2 binding site. Thus, NCAM plays an essential role in NPC proliferation and fate decision during cortical development by regulating profilin2-dependent actin polymerization.

scholarly journals TSC patient-derived isogenic neural progenitor cells reveal altered early neurodevelopmental phenotypes and rapamycin-induced MNK-eIF4E signaling

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Pauline Martin ◽  
Vilas Wagh ◽  
Surya A. Reis ◽  
Serkan Erdin ◽  
Roberta L. Beauchamp ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Large Scale ◽  
Neural Progenitor Cells ◽  
Neurodevelopmental Disorder ◽  
Protein Translation ◽  
Neural Progenitor ◽  
Autism Spectrum ◽  
Patient Specific ◽  
Dependent Manner ◽  
Multiple Organs

Abstract Background Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder with frequent occurrence of epilepsy, autism spectrum disorder (ASD), intellectual disability (ID), and tumors in multiple organs. The aberrant activation of mTORC1 in TSC has led to treatment with mTORC1 inhibitor rapamycin as a lifelong therapy for tumors, but TSC-associated neurocognitive manifestations remain unaffected by rapamycin. Methods Here, we generated patient-specific, induced pluripotent stem cells (iPSCs) from a TSC patient with a heterozygous, germline, nonsense mutation in exon 15 of TSC1 and established an isogenic set of heterozygous (Het), null and corrected wildtype (Corr-WT) iPSCs using CRISPR/Cas9-mediated gene editing. We differentiated these iPSCs into neural progenitor cells (NPCs) and examined neurodevelopmental phenotypes, signaling and changes in gene expression by RNA-seq. Results Differentiated NPCs revealed enlarged cell size in TSC1-Het and Null NPCs, consistent with mTORC1 activation. TSC1-Het and Null NPCs also revealed enhanced proliferation and altered neurite outgrowth in a genotype-dependent manner, which was not reversed by rapamycin. Transcriptome analyses of TSC1-NPCs revealed differentially expressed genes that display a genotype-dependent linear response, i.e., genes upregulated/downregulated in Het were further increased/decreased in Null. In particular, genes linked to ASD, epilepsy, and ID were significantly upregulated or downregulated warranting further investigation. In TSC1-Het and Null NPCs, we also observed basal activation of ERK1/2, which was further activated upon rapamycin treatment. Rapamycin also increased MNK1/2-eIF4E signaling in TSC1-deficient NPCs. Conclusion MEK-ERK and MNK-eIF4E pathways regulate protein translation, and our results suggest that aberrant translation distinct in TSC1/2-deficient NPCs could play a role in neurodevelopmental defects. Our data showing upregulation of these signaling pathways by rapamycin support a strategy to combine a MEK or a MNK inhibitor with rapamycin that may be superior for TSC-associated CNS defects. Importantly, our generation of isogenic sets of NPCs from TSC patients provides a valuable platform for translatome and large-scale drug screening studies. Overall, our studies further support the notion that early developmental events such as NPC proliferation and initial process formation, such as neurite number and length that occur prior to neuronal differentiation, represent primary events in neurogenesis critical to disease pathogenesis of neurodevelopmental disorders such as ASD.

scholarly journals IGF-I instructs multipotent adult neural progenitor cells to become oligodendrocytes

2004 ◽  
Vol 164 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Jenny Hsieh ◽  
James B. Aimone ◽  
Brian K. Kaspar ◽  
Tomoko Kuwabara ◽  
Kinichi Nakashima ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Single Molecule ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Neural Progenitor ◽  
Protein Signaling ◽  
Adult Rat ◽  
Morphogenetic Protein ◽  
Modeling Analysis ◽  
Igf I

Adult multipotent neural progenitor cells can differentiate into neurons, astrocytes, and oligodendrocytes in the mammalian central nervous system, but the molecular mechanisms that control their differentiation are not yet well understood. Insulin-like growth factor I (IGF-I) can promote the differentiation of cells already committed to an oligodendroglial lineage during development. However, it is unclear whether IGF-I affects multipotent neural progenitor cells. Here, we show that IGF-I stimulates the differentiation of multipotent adult rat hippocampus-derived neural progenitor cells into oligodendrocytes. Modeling analysis indicates that the actions of IGF-I are instructive. Oligodendrocyte differentiation by IGF-I appears to be mediated through an inhibition of bone morphogenetic protein signaling. Furthermore, overexpression of IGF-I in the hippocampus leads to an increase in oligodendrocyte markers. These data demonstrate the existence of a single molecule, IGF-I, that can influence the fate choice of multipotent adult neural progenitor cells to an oligodendroglial lineage.

scholarly journals Acetylation of Cavin-1 Promotes Lipolysis in White Adipose Tissue

2017 ◽  
Vol 37 (16) ◽  
Author(s):  
Shui-Rong Zhou ◽  
Liang Guo ◽  
Xu Wang ◽  
Yang Liu ◽  
Wan-Qiu Peng ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Molecular Mechanisms ◽  
Hormone Sensitive Lipase ◽  
Dependent Manner ◽  
Nutritional Regulation ◽  
Fat Mobilization ◽  
Hormone Sensitive ◽  
Shed Light

ABSTRACT White adipose tissue (WAT) serves as a reversible energy storage depot in the form of lipids in response to nutritional status. Cavin-1, an essential component in the biogenesis of caveolae, is a positive regulator of lipolysis in adipocytes. However, molecular mechanisms of cavin-1 in the modulation of lipolysis remain poorly understood. Here, we showed that cavin-1 was acetylated at lysines 291, 293, and 298 (3K), which were under nutritional regulation in WAT. We further identified GCN5 as the acetyltransferase and Sirt1 as the deacetylase of cavin-1. Acetylation-mimetic 3Q mutants of cavin-1 augmented fat mobilization in 3T3-L1 adipocytes and zebrafish. Mechanistically, acetylated cavin-1 preferentially interacted with hormone-sensitive lipase and recruited it to the caveolae, thereby promoting lipolysis. Our findings shed light on the essential role of cavin-1 in regulating lipolysis in an acetylation-dependent manner in WAT.

scholarly journals Identification of neural progenitor cells and their progeny reveals long distance migration in the developing octopus brain

2021 ◽  
Author(s):  
Astrid Deryckere ◽  
Ruth Styfhals ◽  
Ali Murat Elagoz ◽  
Gregory E. Maes ◽  
Eve Seuntjens
Keyword(s):  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Lineage Tracing ◽  
Octopus Vulgaris ◽  
Long Distance ◽  
Histological Techniques ◽  
Large Brain ◽  
Central Brain ◽  
Dividing Cells ◽  
Newborn Neurons

AbstractCephalopods have evolved nervous systems that parallel the complexity of mammalian brains in terms of neuronal numbers and richness in behavioral output. How the cephalopod brain develops has only been described at the morphological level, and it remains unclear where the progenitor cells are located and what molecular factors drive neurogenesis. Using histological techniques, we located dividing cells, neural progenitors and postmitotic neurons in Octopus vulgaris embryos. Our results indicate that progenitors are located outside the central brain cords in the lateral lips adjacent to the eyes, suggesting that newly formed neurons migrate into the cords. Lineage tracing experiments then showed that progenitors, depending on their location in the lateral lips, generate neurons for the different lobes. The finding that octopus newborn neurons migrate over long distances is reminiscent of vertebrate neurogenesis and suggests it might be a fundamental strategy for large brain development.

scholarly journals Comparative Microarray Analysis of Proliferating and Differentiating Murine ENS Progenitor Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Peter Helmut Neckel ◽  
Roland Mohr ◽  
Ying Zhang ◽  
Bernhard Hirt ◽  
Lothar Just
Keyword(s):  
Cell Cycle ◽  
Progenitor Cells ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Neural Progenitor ◽  
Developmental Dysplasia ◽  
Cellular Mechanisms ◽  
Differentiation Markers ◽  
Early Differentiation

Postnatal neural progenitor cells of the enteric nervous system are a potential source for future cell replacement therapies of developmental dysplasia like Hirschsprung’s disease. However, little is known about the molecular mechanisms driving the homeostasis and differentiation of this cell pool. In this work, we conducted Affymetrix GeneChip experiments to identify differences in gene regulation between proliferation and early differentiation of enteric neural progenitors from neonatal mice. We detected a total of 1333 regulated genes that were linked to different groups of cellular mechanisms involved in cell cycle, apoptosis, neural proliferation, and differentiation. As expected, we found an augmented inhibition in the gene expression of cell cycle progression as well as an enhanced mRNA expression of neuronal and glial differentiation markers. We further found a marked inactivation of the canonical Wnt pathway after the induction of cellular differentiation. Taken together, these data demonstrate the various molecular mechanisms taking place during the proliferation and early differentiation of enteric neural progenitor cells.

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