| 1. |
|
|
| 2. |
- Canals, Isaac, et al.
(författare)
-
Rapid and efficient induction of functional astrocytes from human pluripotent stem cells
- 2018
-
Ingår i: Nature Methods. - : Springer Science and Business Media LLC. - 1548-7091 .- 1548-7105. ; 15:9, s. 693-696
-
Tidskriftsartikel (refereegranskat)abstract
- The derivation of astrocytes from human pluripotent stem cells is currently slow and inefficient. We demonstrate that overexpression of the transcription factors SOX9 and NFIB in human pluripotent stem cells rapidly and efficiently yields homogeneous populations of induced astrocytes. In our study these cells exhibited molecular and functional properties resembling those of adult human astrocytes and were deemed suitable for disease modeling. Our method provides new possibilities for the study of human astrocytes in health and disease.
|
|
| 3. |
- Chanoumidou, Konstantina, et al.
(författare)
-
Groucho related gene 5 (GRG5) is involved in embryonic and neural stem cell state decisions
- 2018
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- Groucho related gene 5 (GRG5) is a multifunctional protein that has been implicated in late embryonic and postnatal mouse development. Here, we describe a previously unknown role of GRG5 in early developmental stages by analyzing its function in stem cell fate decisions. By both loss and gain of function approaches we demonstrate that ablation of GRG5 deregulates the Embryonic Stem Cell (ESC) pluripotent state whereas its overexpression leads to enhanced self-renewal and acquisition of cancer cell-like properties. The malignant characteristics of teratomas generated by ESCs that overexpress GRG5 reveal its pro-oncogenic potential. Furthermore, transcriptomic analysis and cell differentiation approaches underline GRG5 as a multifaceted signaling regulator that represses mesendodermal-related genes. When ESCs exit pluripotency, GRG5 promotes neuroectodermal specification via Wnt and BMP signaling suppression. Moreover, GRG5 promotes the neuronal reprogramming of fibroblasts and maintains the self-renewal of Neural Stem Cells (NSCs) by sustaining the activity of Notch/Hes and Stat3 signaling pathways. In summary, our results demonstrate that GRG5 has pleiotropic roles in stem cell biology functioning as a stemness factor and a neural fate specifier.
|
|
| 4. |
- Chapman, Katie, et al.
(författare)
-
Inflammation without neuronal death triggers striatal neurogenesis comparable to stroke.
- 2015
-
Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 83:Aug 20, s. 1-15
-
Tidskriftsartikel (refereegranskat)abstract
- Ischemic stroke triggers neurogenesis from neural stem/progenitor cells (NSPCs) in the subventricular zone (SVZ) and migration of newly formed neuroblasts towards the damaged striatum where they differentiate to mature neurons. Whether it is the injury per se or the associated inflammation that gives rise to this endogenous neurogenic response is unknown. Here we showed that inflammation without corresponding neuronal loss caused by intrastriatal lipopolysaccharide (LPS) injection leads to striatal neurogenesis in rats comparable to that after a 30min middle cerebral artery occlusion, as characterized by striatal DCX+ neuroblast recruitment and mature NeuN+/BrdU+ neuron formation. Using global gene expression analysis, changes in several factors that could potentially regulate striatal neurogenesis were identified in microglia sorted from SVZ and striatum of LPS-injected and stroke-subjected rats. Among the upregulated factors, one chemokine, CXCL13, was found to promote neuroblast migration from neonatal mouse SVZ explants in vitro. However, neuroblast migration to the striatum was not affected in constitutive CXCL13 receptor CXCR5(-/-) mice subjected to stroke. Infarct volume and pro-inflammatory M1 microglia/macrophage density were increased in CXCR5(-/-) mice, suggesting that microglia-derived CXCL13, acting through CXCR5, might be involved in neuroprotection following stroke. Our findings raise the possibility that the inflammation accompanying an ischemic insult is the major inducer of striatal neurogenesis after stroke.
|
|
| 5. |
- Ganic, Elvira, et al.
(författare)
-
MafA-Controlled Nicotinic Receptor Expression Is Essential for Insulin Secretion and Is Impaired in Patients with Type 2 Diabetes.
- 2016
-
Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 14:8, s. 1991-2002
-
Tidskriftsartikel (refereegranskat)abstract
- Monoamine and acetylcholine neurotransmitters from the autonomic nervous system (ANS) regulate insulin secretion in pancreatic islets. The molecular mechanisms controlling neurotransmitter signaling in islet β cells and their impact on diabetes development are only partially understood. Using a glucose-intolerant, MafA-deficient mouse model, we demonstrate that MAFA controls ANS-mediated insulin secretion by activating the transcription of nicotinic (ChrnB2 and ChrnB4) and adrenergic (Adra2A) receptor genes, which are integral parts of acetylcholine- and monoamine-signaling pathways. We show that acetylcholine-mediated insulin secretion requires nicotinic signaling and that nicotinic receptor expression is positively correlated with insulin secretion and glycemic control in human donor islets. Moreover, polymorphisms spanning MAFA-binding regions within the human CHRNB4 gene are associated with type 2 diabetes. Our data show that MAFA transcriptional activity is required for establishing β cell sensitivity to neurotransmitter signaling and identify nicotinic signaling as a modulator of insulin secretion impaired in type 2 diabetes.
|
|
| 6. |
- Hansen, Marita Grønning, et al.
(författare)
-
In Vitro Functional Characterization of Human Neurons and Astrocytes Using Calcium Imaging and Electrophysiology
- 2019
-
Ingår i: Methods in molecular biology (Clifton, N.J.). - New York, NY : Springer New York. - 1940-6029. ; 1919, s. 73-88
-
Tidskriftsartikel (refereegranskat)abstract
- Recent progress in stem cell biology and epigenetic reprogramming has opened up previously unimaginable possibilities to study and develop regenerative approaches for neurological disorders. Human neurons and glial cells can be generated by differentiation of embryonic and neural stem cells and from somatic cells through reprogramming to pluripotency (followed by differentiation) as well as by direct conversion. All of these cells have the potential to be used for studying and treating neurological disorders. However, before considering using human neural cells derived from these sources for modelling or regenerative purposes, they need to be verified in terms of functionality and similarity to endogenous cells in the central nervous system (CNS).In this chapter, we describe how to assess functionality of neurons and astrocytes derived from stem cells and through direct reprogramming, using calcium imaging and electrophysiology.
|
|
| 7. |
- Mall, Moritz, et al.
(författare)
-
Myt1l safeguards neuronal identity by actively repressing many non-neuronal fates
- 2017
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 544:7649, s. 245-249
-
Tidskriftsartikel (refereegranskat)abstract
- Normal differentiation and induced reprogramming require the activation of target cell programs and silencing of donor cell programs. In reprogramming, the same factors are often used to reprogram many different donor cell types. As most developmental repressors, such as RE1-silencing transcription factor (REST) and Groucho (also known as TLE), are considered lineage-specific repressors, it remains unclear how identical combinations of transcription factors can silence so many different donor programs. Distinct lineage repressors would have to be induced in different donor cell types. Here, by studying the reprogramming of mouse fibroblasts to neurons, we found that the pan neuron-specific transcription factor Myt1-like (Myt1l) exerts its pro-neuronal function by direct repression of many different somatic lineage programs except the neuronal program. The repressive function of Myt1l is mediated via recruitment of a complex containing Sin3b by binding to a previously uncharacterized N-terminal domain. In agreement with its repressive function, the genomic binding sites of Myt1l are similar in neurons and fibroblasts and are preferentially in an open chromatin configuration. The Notch signalling pathway is repressed by Myt1l through silencing of several members, including Hes1. Acute knockdown of Myt1l in the developing mouse brain mimicked a Notch gain-of-function phenotype, suggesting that Myt1l allows newborn neurons to escape Notch activation during normal development. Depletion of Myt1l in primary postmitotic neurons de-repressed non-neuronal programs and impaired neuronal gene expression and function, indicating that many somatic lineage programs are actively and persistently repressed by Myt1l to maintain neuronal identity. It is now tempting to speculate that similar 'many-but-one' lineage repressors exist for other cell fates; such repressors, in combination with lineage-specific activators, would be prime candidates for use in reprogramming additional cell types.
|
|
| 8. |
- Miskinyte, Giedre, et al.
(författare)
-
Direct conversion of human fibroblasts to functional excitatory cortical neurons integrating into human neural networks
- 2017
-
Ingår i: Stem Cell Research and Therapy. - : Springer Science and Business Media LLC. - 1757-6512. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Human fibroblasts can be directly converted to several subtypes of neurons, but cortical projection neurons have not been generated. Methods: Here we screened for transcription factor combinations that could potentially convert human fibroblasts to functional excitatory cortical neurons. The induced cortical (iCtx) cells were analyzed for cortical neuronal identity using immunocytochemistry, single-cell quantitative polymerase chain reaction (qPCR), electrophysiology, and their ability to integrate into human neural networks in vitro and ex vivo using electrophysiology and rabies virus tracing. Results: We show that a combination of three transcription factors, BRN2, MYT1L, and FEZF2, have the ability to directly convert human fibroblasts to functional excitatory cortical neurons. The conversion efficiency was increased to about 16% by treatment with small molecules and microRNAs. The iCtx cells exhibited electrophysiological properties of functional neurons, had pyramidal-like cell morphology, and expressed key cortical projection neuronal markers. Single-cell analysis of iCtx cells revealed a complex gene expression profile, a subpopulation of them displaying a molecular signature closely resembling that of human fetal primary cortical neurons. The iCtx cells received synaptic inputs from co-cultured human fetal primary cortical neurons, contained spines, and expressed the postsynaptic excitatory scaffold protein PSD95. When transplanted ex vivo to organotypic cultures of adult human cerebral cortex, the iCtx cells exhibited morphological and electrophysiological properties of mature neurons, integrated structurally into the cortical tissue, and received synaptic inputs from adult human neurons. Conclusions: Our findings indicate that functional excitatory cortical neurons, generated here for the first time by direct conversion of human somatic cells, have the capacity for synaptic integration into adult human cortex.
|
|
| 9. |
- Miskinyte, Giedre, et al.
(författare)
-
Transcription factor programming of human ES cells generates functional neurons expressing both upper and deep layer cortical markers
- 2018
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:10
-
Tidskriftsartikel (refereegranskat)abstract
- Human neurodegenerative disorders affect specific types of cortical neurons. Efficient protocols for the generation of such neurons for cell replacement, disease modeling and drug screening are highly warranted. Current methods for the production of cortical neurons from human embryonic stem (ES) cells are often time-consuming and inefficient, and the functional properties of the generated cells have been incompletely characterized. Here we have used transcription factor (TF) programming with the aim to induce rapid differentiation of human ES cells to layer-specific cortical neurons (hES-iNs). Three different combinations of TFs, NEUROGENIN 2 (NGN2) only, NGN2 plus Forebrain Embryonic Zinc Finger-Like Protein 2 (FEZF2), and NGN2 plus Special AT-Rich Sequence-Binding Protein 2 (SATB2), were delivered to human ES cells by lentiviral vectors. We observed only subtle differences between the TF combinations, which all gave rise to the formation of pyramidal-shaped cells, morphologically resembling adult human cortical neurons expressing cortical projection neuron (PN) markers and with mature electrophysiological properties. Using ex vivo transplantation to human organotypic cultures, we found that the hES-iNs could integrate into adult human cortical networks. We obtained no evidence that the hES-iNs had acquired a distinct cortical layer phenotype. Instead, our single-cell data showed that the hES-iNs, similar to fetal human cortical neurons, expressed both upper and deep layer cortical neuronal markers. Taken together, our findings provide evidence that TF programming can direct human ES cells towards cortical neurons but that the generated cells are transcriptionally profiled to generate both upper and deep layer cortical neurons. Therefore, most likely additional cues will be needed if these cells should adopt a specific cortical layer and area identity.
|
|
| 10. |
- Warnling Conradson, Wiweka, et al.
(författare)
-
Lärare & elev : rättsliga aspekter och etiska dilemman
- 2018. - 2
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Denna bok inom det skoljuridiska området fokuserar på mötet mellan lärare och elev och vilka rättsliga aspekter, ofta förknippade med etiska dilemman, som detta kan aktualisera. Tanken är att lära sig se dessa aspekter och dilemman i vardagliga situationer för att på så sätt kunna parera ett antal s.k. blindskär i yrkesrollen som lärare.
|
|
| 11. |
- Wattananit, Somsak, et al.
(författare)
-
Monocyte-derived macrophages contribute to spontaneous long-term functional recovery after stroke in mice
- 2016
-
Ingår i: The Journal of Neuroscience. - 0270-6474. ; 36:15, s. 4182-4195
-
Tidskriftsartikel (refereegranskat)abstract
- Stroke is a leading cause of disability and currently lacks effective therapy enabling long-term functional recovery. Ischemic brain injury causes local inflammation, which involves both activated resident microglia and infiltrating immune cells, including monocytes. Monocyte-derived macrophages (MDMs) exhibit a high degree of functional plasticity. Here, we determined the role of MDMs in longterm spontaneous functional recovery after middle cerebral artery occlusion in mice. Analyses by flow cytometry and immunocytochemistry revealed that monocytes home to the stroke-injured hemisphere., and that infiltration peaks 3 d after stroke. At day 7, half of the infiltratingMDMsexhibited a bias toward a proinflammatory phenotype and the other half toward an anti-inflammatory phenotype, but during the subsequent 2 weeks, MDMs with an anti-inflammatory phenotype dominated. Blocking monocyte recruitment using the anti-CCR2 antibody MC-21 during the first week after stroke abolished long-term behavioral recovery, as determined in corridor and staircase tests, and drastically decreased tissue expression of anti-inflammatory genes, including TGFβ, CD163, and Ym1. Our results show that spontaneously recruited monocytes to the injured brain early after the insult contribute to long-term functional recovery after stroke.
|
|
