Human Neuronal Progenitor Cells Research Articles

Discovery of novel heart rate-associated loci using the Exome Chip.

Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to discover new genetic loci associated with heart rate from Exome Chip meta-analyses.Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods.We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) and fetal muscle samples by including our novel variants.Our findings advance the knowledge of the genetic architecture of heart rate, and indicate new candidate genes for follow-up functional studies.

Apolipoprotein E4 Suppresses Neuronal-Specific Gene Expression in Maturing Neuronal Progenitor Cells Exposed to HIV

The apolipoprotein ε4 gene allele and the apolipoprotein E4 protein (ApoE4) are important host susceptibility factors linked to neurocognitive disorders associated with HIV infection or Alzheimer’s disease. Our previous studies showed differential effects of the two most common human ApoE genotypes, APOE3/3 and APOE3/4, on gene expression by differentiating human neuroepithelial progenitor cells continuously exposed to HIV. To investigate the effects of ApoE3 versus ApoE4 isoforms specifically on maturing neurons, we adapted a human neuronal progenitor cell line, hNP1, with ApoE genotype APOE3/3. Differentiating hNP1 cells were exposed for 16 days to HIV- or mock-infected supernatants and to added recombinant ApoE isoforms rApoE3 or rApoE4 to modulate the ApoE phenotype of the cells. Gene expression was investigated using microarray and functional genomics analyses. Added rApoE3 differentially affected 36 genes. Added rApoE4 differentially affected 85 genes; 41 of which were differentially expressed only in HIV or mock-supernatant treated cells, and 80% of which were downregulated. Genes differentially downregulated only by rApoE4 represented multiple neuronal functions related to neurogenesis. Approximately five times more genes were differentially enriched by rApoE4 versus rApoE3 in the Gene Ontology (GO) cellular process analysis, with 4 orders of magnitude greater significance. Half of the top 10 GO processes affected by rApoE4 treatment were neurogenesis-related. The largest differences in gene expression between the two isoforms were observed within the HIV-exposed cultures, suggesting that HIV exposure magnifies ApoE4’s suppressive effect on neuronal gene expression. This study provides evidence for neuronal-specific responses to ApoE4 that could affect neurogenesis and neuronal survival.

Differential epigenetic effects of chlorpyrifos and arsenic in proliferating and differentiating human neural progenitor cells.

Understanding the underlying temporal and mechanistic responses to neurotoxicant exposures during sensitive periods of neuronal development are critical for assessing the impact of these exposures on developmental processes. To investigate the importance of timing of neurotoxicant exposure for perturbation of epigenetic regulation, we exposed human neuronal progenitor cells (hNPCs) to chlorpyrifos (CP) and sodium arsenite (As; positive control) during proliferation and differentiation. CP or As treatment effects on hNPCs morphology, cell viability, and changes in protein expression levels of neural differentiation and cell stress markers, and histone H3 modifications were examined. Cell viability, proliferation/differentiation status, and epigenetic results suggest that hNPCs cultures respond to CP and As treatment with different degrees of sensitivity. Histone modifications, as measured by changes in histone H3 phosphorylation, acetylation and methylation, varied for each toxicant and growth condition, suggesting that differentiation status can influence the epigenetic effects of CP and As exposures.

Abstract 1244: A novel microtubule-disrupting indole-based chalcone that induces caspase-independent cell death in glioblastoma and melanoma cells

Abstract Indolyl-pyridinyl-propenones (a subclass of synthetic indole-based chalcones) have been shown to induce a novel form of cell death termed ‘methuosis’ in glioblastoma and other tumor cell lines. This form of cell death is caspase-independent and involves massive vacuolization of macropinosome and endosome compartments. In the course of structure-activity relationship studies identifying a lead compound, 3-(5-methoxy-2-methyl-1H-indol-3-yl)-1-(4-pyridinyl)-2-propene-1-one (abbreviated 5-MOMIPP), we discovered that changing the methoxy substitution from the 5-position to the 6-position on the indole ring markedly alters the biological activity of the compound. 6-MOMIPP exhibits potent anti-proliferative and cytotoxic activity in glioblastoma, melanoma and other cancer cell lines at a concentration of 100 nM, nearly two orders of magnitude lower than the maximally effective concentration of 5-MOMIPP. Instead of inducing methuosis, 6-MOMIPP (at > 500 nM) immediately disrupts microtubules, as confirmed by immunofluorescence microscopy. By 24 h the majority of the cells are rounded and arrested in mitosis, and by 48 h cell viability is greatly reduced. The few remaining live cells contain multiple abnormal nuclei. Extensive cell death occurs before activation of caspases 3, 7 and 9 can be detected. Scintillation proximity assays show that 6-MOMIPP competes with 3H-colchicine, but not 3H-vinblastine, for binding to tubulin. Studies aimed at testing the toxicity of 6-MOMIPP in normal cells are in progress, but work with a closely related microtubule-active indole-based chalcone indicates that toxicity is substantially reduced in quiescent human fibroblasts and rat neuronal progenitor cells. Although drugs targeted to microtubules (e.g., Vinca alkaloids and taxanes) are widely used as anti-neoplastic agents, they have shown little efficacy in treating primary or metastatic brain tumors, partly due to limited penetrance of the blood-brain barrier (BBB). Preliminary pharmacokinetic studies in mice show that 6-MOMIPP injected IP can readily cross the BBB, attaining brain concentrations nearly equal to plasma concentrations within 30 min to 1 h. Therefore, these preliminary findings suggest that 6-MOMIPP merits further preclinical evaluation as a potential therapeutic agent for primary and metastatic brain tumors. Supported by NIH grant CA115495 and by the Helen and Harold McMaster Endowment. Citation Format: Shengnan Du, Jeffrey G. Sarver, Christopher J. Trabbic, Paul W. Erhardt, Jean H. Overmeyer, William A. Maltese. A novel microtubule-disrupting indole-based chalcone that induces caspase-independent cell death in glioblastoma and melanoma cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1244.

L1 Retrotransposition in Neural Progenitor Cells.

Long interspersed nucleotide element 1 (LINE-1 or L1) is a family of non-LTR retrotransposons that can replicate and reintegrate into the host genome. L1s have considerably influenced mammalian genome evolution by retrotransposing during germ cell development or early embryogenesis, leading to massive genome expansion. For many years, L1 retrotransposons were viewed as a selfish DNA parasite that had no contribution in somatic cells. Historically, L1s were thought to only retrotranspose during gametogenesis and in neoplastic processes, but recent studies have shown that L1s are extremely active in the mouse, rat, and human neuronal progenitor cells (NPCs). These de novo L1 insertions can impact neuronal transcriptional expression, creating unique transcriptomes of individual neurons, possibly contributing to the uniqueness of the individual cognition and mental disorders in humans.

Arctic ground squirrel neuronal progenitor cells resist oxygen and glucose deprivation-induced death.

To investigate the influence of ischemia/reperfusion on arctic ground squirrel (AGS) neuronal progenitor cells (NPCs), we subjected these cultured cells to oxygen and glucose deprivation. AGS NPCs were expanded and differentiated into NPCs and as an ischemia vulnerable control, commercially available human NPCs (hNPCs) were seeded from thawed NPCs. NPCs, identified by expression of TUJ1 were seen at 14-21 d in vitro (DIV). Cultures were exposed to control conditions, hypoxia, oxygen and glucose deprivation or glucose deprivation alone or following return to normal conditions to model reperfusion. Cell viability and death were assessed from loss of ATP as well as from measures of alamarBlue(®) and lactate dehydrogenase in the media and from counts of TUJ1 positive cells using immunocytochemistry. Dividing cells were identified by expression of Ki67 and phenotyped by double labeling with GFAP, MAP2ab or TUJ1. We report that when cultured in NeuraLife™, AGS cells remain viable out to 21 DIV, continue to express TUJ1 and begin to express MAP2ab. Viability of hNPCs assessed by fluorescence alamarBlue (arbitrary units) depends on both glucose and oxygen availability [viability of hNPCs after 24 h oxygen glucose deprivation (OGD) with return of oxygen and glucose decreased from 48151 ± 4551 in control cultures to 43481 ± 2413 after OGD, P < 0.05]. By contrast, when AGS NPCs are exposed to the same OGD with reperfusion at 14 DIV, cell viability assessed by alamarBlue increased from 165305 ± 11719 in control cultures to 196054 ± 13977 after OGD. Likewise AGS NPCs recovered ATP (92766 ± 6089 in control and 92907 ± 4290 after modeled reperfusion; arbitrary luminescence units), and doubled in the ratio of TUJ1 expressing neurons to total dividing cells (0.11 ± 0.04 in control cultures vs 0.22 ± 0.2 after modeled reperfusion, P < 0.05). Maintaining AGS NPCs for a longer time in culture lowered resistance to injury, however, did not impair proliferation of NPCs relative to other cell lineages after oxygen deprivation followed by re-oxygenation. Ischemic-like insults decrease viability and increase cell death in cultures of human NPCs. Similar conditions have less affect on cell death and promote proliferation in AGS NPCs.

Generation of human neuronal progenitor cells from human wharton's jelly-derived mesenchymal stem cells (WjMSCs) to study GDM-induced changes in the fetal brain

Generation of human neuronal progenitor cells from human wharton's jelly-derived mesenchymal stem cells (WjMSCs) to study GDM-induced changes in the fetal brain

Transplantation of Human Neural Progenitor Cells Expressing IGF-1 Enhances Retinal Ganglion Cell Survival.

We have previously characterized human neuronal progenitor cells (hNP) that can adopt a retinal ganglion cell (RGC)-like morphology within the RGC and nerve fiber layers of the retina. In an effort to determine whether hNPs could be used a candidate cells for targeted delivery of neurotrophic factors (NTFs), we evaluated whether hNPs transfected with an vector that expresses IGF-1 in the form of a fusion protein with tdTomato (TD), would increase RGC survival in vitro and confer neuroprotective effects in a mouse model of glaucoma. RGCs co-cultured with hNPIGF-TD cells displayed enhanced survival, and increased neurite extension and branching as compared to hNPTD or untransfected hNP cells. Application of various IGF-1 signaling blockers or IGF-1 receptor antagonists abrogated these effects. In vivo, using a model of glaucoma we showed that IOP elevation led to reductions in retinal RGC count. In this model, evaluation of retinal flatmounts and optic nerve cross sections indicated that only hNPIGF-TD cells effectively reduced RGC death and showed a trend to improve optic nerve axonal loss. RT-PCR analysis of retina lysates over time showed that the neurotrophic effects of IGF-1 were also attributed to down-regulation of inflammatory and to some extent, angiogenic pathways. This study shows that neuronal progenitor cells that hone into the RGC and nerve fiber layers may be used as vehicles for local production and delivery of a desired NTF. Transplantation of hNPIGF-TD cells improves RGC survival in vitro and protects against RGC loss in a rodent model of glaucoma. Our findings have provided experimental evidence and form the basis for applying cell-based strategies for local delivery of NTFs into the retina. Application of cell-based delivery may be extended to other disease conditions beyond glaucoma.

Dysregulation of miR-34a links neuronal development to genetic risk factors for bipolar disorder.

Bipolar disorder (BD) is a heritable neuropsychiatric disorder with largely unknown pathogenesis. Given their prominent role in brain function and disease, we hypothesized that microRNAs (miRNAs) might be of importance for BD. Here we show that levels of miR-34a, which is predicted to target multiple genes implicated as genetic risk factors for BD, are increased in postmortem cerebellar tissue from BD patients, as well as in BD patient-derived neuronal cultures generated by reprogramming of human fibroblasts into induced neurons (iNs) or into induced pluripotent stem cells (iPSCs) subsequently differentiated into neurons. Of the predicted miR-34a targets, we validated the BD risk genes ankyrin-3 (ANK3) and voltage-dependent L-type calcium channel subunit beta-3 (CACNB3) as direct miR-34a targets. Using human iPSC-derived neuronal progenitor cells (hNPCs), we further show that enhancement of miR-34a expression impairs neuronal differentiation, expression of synaptic proteins and neuronal morphology, whereas reducing endogenous miR-34a expression enhances dendritic elaboration. Taken together, we propose that miR-34a serves as a critical link between multiple etiological factors for BD and its pathogenesis through the regulation of a molecular network essential for neuronal development and synaptogenesis.

Recent Advances from the Bench Toward the Bedside in Alzheimer's Disease

Recent Advances from the Bench Toward the Bedside in Alzheimer's Disease

Transient but not permanent benefit of neuronal progenitor cell therapy after traumatic brain injury: potential causes and translational consequences.

Background: Numerous studies have reported a beneficial impact of neural progenitor cell transplantation on functional outcome after traumatic brain injury (TBI) during short and medium follow-up periods. However, our knowledge regarding long-term functional effects is fragmentary while a direct comparison between local and systemic transplantation is missing so far.Objectives: This study investigated the long-term (12 week) impact of human fetal neuronal progenitor cell (hNPC) transplantation 24 h after severe TBI in rats.Methods: Cells were either transplanted stereotactically (1 × 105) into the putamen or systemically (5 × 105) via the tail vein. Control animals received intravenous transplantation of vehicle solution.Results: An overall functional benefit was observed after systemic, but not local hNPC transplantation by area under the curve analysis (p < 0.01). Surprisingly, this effect vanished during later stages after TBI with all groups exhibiting comparable functional outcomes 84 days after TBI. Investigation of cell-mediated inflammatory processes revealed increasing microglial activation and macrophage presence during these stages, which was statistically significant after systemic cell administration (p < 0.05). Intracerebral hNPC transplantation slightly diminished astrogliosis in perilesional areas (p < 0.01), but did not translate into a permanent functional benefit. No significant effects on angiogenesis were observed among the groups.Conclusion: Our results suggest the careful long-term assessment of cell therapies for TBI, as well as to identify potential long-term detrimental effects of such therapies before moving on to clinical trials. Moreover, immunosuppressive protocols, though widely used, should be rigorously assessed for their applicability in the respective setup.

Perianal implantation of bioengineered human internal anal sphincter constructs intrinsically innervated with human neural progenitor cells

The internal anal sphincter (IAS) is a major contributing factor to pressure within the anal canal and is required for maintenance of rectoanal continence. IAS damage or weakening results in fecal incontinence. We have demonstrated that bioengineered, intrinsically innervated, human IAS tissue replacements possess key aspects of IAS physiology, such as the generation of spontaneous basal tone and contraction/relaxation in response to neurotransmitters. The objective of this study is to demonstrate the feasibility of implantation of bioengineered IAS constructs in the perianal region of athymic rats. Human IAS tissue constructs were bioengineered from isolated human IAS circular smooth muscle cells and human enteric neuronal progenitor cells. After maturation of the bioengineered constructs in culture, they were implanted operatively into the perianal region of athymic rats. Platelet-derived growth factor was delivered to the implanted constructs through a microosmotic pump. Implanted constructs were retrieved from the animals 4 weeks postimplantation. Animals tolerated the implantation well, and there were no early postoperative complications. Normal stooling was observed during the implantation period. At harvest, implanted constructs were adherent to the perirectal rat tissue and appeared healthy and pink. Immunohistochemical analysis revealed neovascularization. Implanted smooth muscle cells maintained contractile phenotype. Bioengineered constructs responded in vitro in a tissue chamber to neuronally evoked relaxation in response to electrical field stimulation and vasoactive intestinal peptide, indicating the preservation of neuronal networks. Our results indicate that bioengineered innervated IAS constructs can be used to augment IAS function in an animal model. This is a regenerative medicine based therapy for fecal incontinence that would directly address the dysfunction of the IAS muscle.

Newly Synthesized Indolylmalemide PDA-66 and Its Derivates Induce Antiproliferative Effects In Acute Lymphoblastic Leukemia

The PI3K/Akt pathway is dysregulated is some acute lymphoblastic leukemias (ALL) and might therefore serve as therapeutic target. Indolylmaleimides exhibit inhibitory potencies against different protein kinases -like glycogen synthase kinase 3 (GSK3β) or protein kinase c- influencing thereby several cellular processes. Recently, it was demonstrated that PDA-66, a newly synthesized indolylmalemide based on the well known GSK3β inhibitor SB-216763, hinders microtubule polymerization in human neuronal progenitor and neuroblastoma cells. GSK3β is a downstream substrate of the PI3K/Akt and Wnt pathways and is often deregulated in tumor tissues. Herein, we investigated the effects of PDA-66 and its derivates (PDA-66E und PDA-377) on B and T-lymphoblastic leukemia cells. MethodsB- and T-ALL cell lines (SEM, RS4;11, REH, Jurkat, MOLT-4 and CEM) were incubated for 72 h with increasing concentrations (0.1 µM-5.0 µM) of PDA-66, PDA-66E, PDA-377 and comparatively analyzed to SB-216763. To evaluate the effect of each substance WST-1 assay, cell proliferation, cell cycle analyses as well as apoptosis rates were determined. Activities of indolylmalemides were analyzed by GSK3β kinase assay. Detection of key molecules of Wnt and PI3K/Akt signaling pathway was performed using Western blot. ResultsPDA-66 and derivates inhibited proliferation and metabolism of ALL cells significantly in a dose dependent manner. Interestingly, all PDA derivates showed a stronger inhibitory effect on proliferation than SB-216763 but the inhibitory effect on GSK3β kinase was lower than SB-216763. Antiproliferative effects of PDA-66 were studied in more detail. The incubation of 1 µM PDA-66 led to condensation of chromatin in the nucleus, karyorrhexis and an increasing amount of vacuoles after 48 h of treatment. PDA-66 influenced the cell cycle distribution of ALL cell lines differently. While RS4;11 and MOLT-4 cells were arrested in G2 phase, SEM cells remained increasingly in G0/1 phase. After 48 h all PDA-66 treated cell lines showed a significant increase in apoptosis compared to control cells (SEM: 2.1 ± 0.9 % to 10.5 ± 1.3 %; RS4;11: 2.5 ± 0.7 % to 7.4 ± 1.1 %; Jurkat: 3.8 ± 0.6 % to 8.3 ± 1.9 %; MOLT-4: 3.7 ± 1.2 % to 16.3 ± 5.1 %). Apoptosis of ALL cells was initiated by cleavage of caspase 3 and 7 and Poly (ADP-ribose) polymerase (PARP). Furthermore, with increasing concentration of PDA-66 a decrease of pGSK3βSer9 was observed after 4 h in SEM cells. However, no influence on the total form of β-catenin was detectable. Nevertheless, there was an influence of PDA-66 on the expression of 4EBP-1 and p4EBP-1Ser65. SEM, RS4;11 and Jurkat cells showed a decrease of the phosphorylated as well as the total form of 4EBP-1 after an incubation of 4 and 24 h.In conclusion, our results demonstrate that the newly synthesized indolymalemides have pronounced antiproliferative effects in ALL cells. In particular, the indolymalemide PDA-66 should be further investigated concerning it's clinical efficiency as well as well as it's intracellular ways of action. Disclosures:No relevant conflicts of interest to declare.

Epoxy cross-linked collagen and collagen-laminin Peptide hydrogels as corneal substitutes.

A bi-functional epoxy-based cross-linker, 1,4-Butanediol diglycidyl ether (BDDGE), was investigated in the fabrication of collagen based corneal substitutes. Two synthetic strategies were explored in the preparation of the cross-linked collagen scaffolds. The lysine residues of Type 1 porcine collagen were directly cross-linked using l,4-Butanediol diglycidyl ether (BDDGE) under basic conditions at pH 11. Alternatively, under conventional methodology, using both BDDGE and 1-Ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as cross-linkers, hydrogels were fabricated under acidic conditions. In this latter strategy, Cu(BF4)2·XH2O was used to catalyze the formation of secondary amine bonds. To date, we have demonstrated that both methods of chemical cross-linking improved the elasticity and tensile strength of the collagen implants. Differential scanning calorimetry and biocompatibility studies indicate comparable, and in some cases, enhanced properties compared to that of the EDC/NHS controls. In vitro studies showed that human corneal epithelial cells and neuronal progenitor cell lines proliferated on these hydrogels. In addition, improvement of cell proliferation on the surfaces of the materials was observed when neurite promoting laminin epitope, IKVAV, and adhesion peptide, YIGSR, were incorporated. However, the elasticity decreased with peptide incorporation and will require further optimization. Nevertheless, we have shown that epoxy cross-linkers should be further explored in the fabrication of collagen-based hydrogels, as alternatives to or in conjunction with carbodiimide cross-linkers.

Autoantibodies against neuronal progenitors in sera from children with autism

The pathological role of autoantibodies in development of CNS disorders is a new idea with growing interest among neuroscientists. The involvement of autoimmune response in the pathogenesis of autism spectrum disorders (ASD) has been suggested by the presence of multiple brain-specific autoantibodies in children with ASD and in their mothers. The possibility of the effect of autoimmunity on neurogenesis and postnatal brain plasticity has not been determined. The presence of autoantibodies against human neuronal progenitor cells (NPCs) stimulated for neuronal differentiation in culture was tested in sera from children with autism (n=20) and age-matched controls (n=18) by immunoblotting and immunocytochemistry. Immunoreactivity against multiple NPCs proteins of molecular sizes of approximately 55kDa, 105kDa, 150kDa, and 210kDa in sera from individuals with autism had a higher incidence and was stronger than in control sera which immunoreacted mainly with a 150kDa protein. The sera from children with autism immunoreacted the strongest with NPCs expressing neuronal markers Tuj1 and doublecortin, but not astrocyte marker GFAP. The epitopes recognized by antibodies from sera were not human-specific because they detected also NPCs in situ in murine hippocampus. The autoimmune reactions against NPCs suggest an impaired tolerance to neural antigens in autism. These autoantibodies may be symptomatic for autism and furthermore, their presence suggests that autoimmunity may affect postnatal neuronal plasticity particularly after impairment of blood–brain barrier. Future studies will determine the diagnostic value of the presence of autoantibodies in autism and the therapeutic value of prevention of autoimmunity in autism.

Elevated IKKα Accelerates the Differentiation of Human Neuronal Progenitor Cells and Induces MeCP2-Dependent BDNF Expression

The IκB kinase α (IKKα) is implicated in the differentiation of epithelial and immune cells. We examined whether IKKα also plays a role in the differentiation and maturation of embryonic human neuronal progenitor cells (NPCs). We find that expression of an extra copy of IKKα (IKKα+) blocks self-renewal and accelerates the differentiation of NPCs. This coincides with reduced expression of the Repressor Element Silencing Transcription Factor/Neuron-Restrictive Silencing Factor (REST/NRSF), which is a prominent inhibitor of neurogenesis, and subsequent induction of the pro-differentiation non-coding RNA, miR-124a. However, the effects of IKKα on REST/NRSF and miR-124a expression are likely to be indirect. IKKα+ neurons display extensive neurite outgrowth and accumulate protein markers of neuronal maturation such as SCG10/stathmin-2, postsynaptic density 95 (PSD95), syntaxin, and methyl-CpG binding protein 2 (MeCP2). Interestingly, IKKα associates with MeCP2 in the nuclei of human neurons and can phosphorylate MeCP2 in vitro. Using chromatin immunoprecipitation assays, we find that IKKα is recruited to the exon-IV brain-derived neurotrophic factor (BDNF) promoter, which is a well-characterized target of MeCP2 activity. Moreover, IKKα induces the transcription of BDNF and knockdown expression of MeCP2 interferes with this event. These studies highlight a role for IKKα in accelerating the differentiation of human NPCs and identify IKKα as a potential regulator of MeCP2 function and BDNF expression.

72 In Situ Implanted Bioengineered Human Internal Anal Sphincter Innervated With Human Enteric Neuronal Progenitor Cells Maintain Myogenic and Neurogenic Physiological Functionality

72 In Situ Implanted Bioengineered Human Internal Anal Sphincter Innervated With Human Enteric Neuronal Progenitor Cells Maintain Myogenic and Neurogenic Physiological Functionality

Erythropoietin enhances cell proliferation and survival of human fetal neuronal progenitors in normoxia

Extensive data reporting the neurogenerative, neuroprotective and neuroregenerative potential of erythropoietin (EPO), mainly on RNA level, can be found in the literature. However, there is still a poor knowledge on the response of neuronal progenitor cells (NPC) upon stimulation with EPO in terms of the protein species involved. Herein, the effect of EPO on the proliferation of human mesencephalic NPC (hmNPC) under normoxia is monitored using cellular assays and proteomic analysis (two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry). The administration of EPO increased the proliferation of hmNPC within 4days after application. It positively influenced the cell-cycle progression by affecting the G2 phase of the cell cycle. A proteomic analysis of the protein expression in hmNPC cultures 4days after EPO treatment identified 8 proteins differentially expressed in EPO-treated cultures. It is likely that one or more of the identified proteins are involved in cellular pathways that promote cell proliferation and differentiation of hmNPC under normoxia. Their further characterization could provide cellular targets for the development of new therapeutic agents to treat CNS injury. Moreover, as EPO signaling is hypoxia-inducible, our findings may also indicate the beneficial effect of EPO to mimic hypoxia, while bypassing its negative effects, to culture human fetal midbrain-derived progenitor cells.

LINE-1 creators of neuronal diversity

Long interspersed nucleotide element 1 (L1) is a family of non-LTR retrotransposons that can replicate and reintegrate into the host genome. L1s have considerably influenced mammalian genome evolution by retrotransposing during germ cell development or early embryogenesis, leading to massive genome expansion. In humans, over 30 % of the genome can be attributed to L1-mediated retrotransposition. Historically, L1s were thought to only retrotranspose during gametogenesis and in neoplastic processes, but recent studies have shown that L1s are extremely active in the mouse, rat, and human neuronal progenitor cells (NPCs). In fact, it is estimated that the hippocampus and other regions of the brain may have multiple insertions per cell. These insertions can dramatically impact neuronal transcriptional expression, creating unique transcriptomes of individual neurons. Furthermore, transcriptional activation of L1 elements mimics the transcription activation of the NeuroD1 gene, suggesting a prominent role of L1 expression during neurogenesis.

LINE-1: creators of neuronal diversity

Long interspersed nucleotide element 1 (L1) is a family of non-LTR retrotransposons that can replicate and reintegrate into the host genome. L1s have considerably influenced mammalian genome evolution by retrotransposing during germ cell development or early embryogenesis, leading to massive genome expansion. In humans, over 30 % of the genome can be attributed to L1-mediated retrotransposition. Historically, L1s were thought to only retrotranspose during gametogenesis and in neoplastic processes, but recent studies have shown that L1s are extremely active in the mouse, rat, and human neuronal progenitor cells (NPCs). In fact, it is estimated that the hippocampus and other regions of the brain may have multiple insertions per cell. These insertions can dramatically impact neuronal transcriptional expression, creating unique transcriptomes of individual neurons. Furthermore, transcriptional activation of L1 elements mimics the transcription activation of the NeuroD1 gene, suggesting a prominent role of L1 expression during neurogenesis.