Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Human stem cell based models of neuronal migration provide insight into neurological disease pathogenesis and potential treatment

ABSTRACT: Neuronal migration defects (NMDs) are among the most common and severe brain abnormalities in humans. Lack of disease models in mice or in human cells has hampered the identification of underlying mechanisms. From patients with severe NMDs we generated iPSCs then differentiated neural progenitor cells (NPCs). On artificial extracellular matrix, patient-derived neuronal cells showed defective migration and impaired neurite outgrowth. From a cohort of 107 families with NMDs, sequencing identified two homozygous C-terminal truncating mutations in CTNNA2, encoding αN-catenin, one of three paralogues of the α-catenin family, involved in epithelial integrity and cell polarity. Patient-derived or CRISPR-targeted CTNNA2- mutant neuronal cells showed defective migration and neurite stability. Recombinant αN-catenin was sufficient to bundle purified actin and to suppress the actin-branching activity of ARP2/3. Small molecule inhibitors of ARP2/3 rescued the CTNNA2 neurite defect. Thus, disease modeling in human cells could be used to understand NMD pathogenesis and develop treatments for associated disorders.

ORGANISM(S): Homo sapiens

PROVIDER: GSE72994 | GEO | 2015/09/15

SECONDARY ACCESSION(S): PRJNA295551

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Knockout of the Arp2/3 complex in epidermis causes a psoriasis-like disease hallmarked by hyperactivation of transcription factor Nrf2 [Epidermis ssRNA-Seq]

Project description:Arp2/3 complex assembles branched actin filaments key to many cellular processes, but its organismal roles remain poorly understood. Here we employed conditional arpc4 knockout mice to study the function of the Arp2/3 complex in the epidermis.We found that depletion of the Arp2/3 complex by knockout of arpc4 results in skin abnormalities at birth that evolve into a severe psoriasis-like disease hallmarked by hyperactivation of transcription factor Nrf2. Knockout of arpc4 in cultured keratinocytes was sufficient to induce nuclear accumulation of Nrf2, upregulation of Nrf2-target genes and decreased filamentous actin levels. Furthermore, pharmacological inhibition of the Arp2/3 complex unmasked the role of branched actin filaments in Nrf2 regulation. Consistently, we unveiled that Nrf2 associates with the actin cytoskeleton in cells and binds to filamentous actin in vitro Finally, we discovered that Arpc4 is downregulated in both human and mouse psoriatic epidermis. Thus, the Arp2/3 complex affects keratinocytes' shape and transcriptome through an actin-based cell-autonomous mechanism that influences epidermal morphogenesis and homeostasis.

2017-11-23 | GSE107265 | GEO

Knockout of the Arp2/3 complex in epidermis causes a psoriasis-like disease hallmarked by hyperactivation of transcription factor Nrf2 [Keratinocytes ssRNA-Seq]

2017-11-23 | GSE107264 | GEO

Arp2/3 complex activity is necessary for mouse ESC differentiation, times formative pluripotency, and enables lineage specification

Project description:Mouse embryonic stem cells (mESCs), a model for differentiation into primed epiblast-like cells (EpiLCs), have revealed transcriptional and epigenetic control of early embryonic development. The control and significance of morphological changes, however, remain less defined. We show marked changes in morphology and actin architectures during differentiation that depend on Arp2/3 complex but not formin activity. Inhibiting Arp2/3 complex activity pharmacologically or genetically does not block exit from naive pluripotency but attenuates increases in EpiLC markers. We find that inhibiting Arp2/3 complex activity delays formative pluripotency and causes globally defective lineage specification as indicated by RNA-sequencing, with significant effects on TBX3-depedendent transcriptional programs. We also identify two previously unreported indicators of mESC differentiation; MRTF and FHL2, which have inverse Arp2/3 complex-dependent nuclear translocation. Our findings on Arp2/3 complex activity in differentiation and the established role of formins in EMT indicate that these two actin nucleators regulate distinct modes of epithelial plasticity

2022-04-01 | GSE175391 | GEO

Arp2/3 Complex Activity Enables Nuclear YAP for Naïve Pluripotency of Human Embryonic Stem Cells

Project description:Our understanding of transitions of human embryonic stem cells between distinct stages of pluripotency relies predominantly on regulation by transcriptional and epigenetic programs with limited insight on the role of established morphological changes. We report remodeling of the actin cytoskeleton of human embryonic stem cells (hESCs) as they transition from primed to naïve pluripotency that includes assembly of a ring of contractile actin filaments encapsulating colonies of naïve hESCs. Activity of the Arp2/3 complex is required for the actin ring, uniform cell mechanics within naïve colonies, nuclear translocation of the Hippo pathway effectors YAP and TAZ, and effective transition to naïve pluripotency. RNA-sequencing analysis confirms that Arp2/3 complex activity regulates Hippo signaling in hESCs, and impaired naïve pluripotency with inhibited Arp2/3 complex activity is rescued by expressing a constitutively active, nuclear-localized YAP-S127A. Moreover, expression of YAP-S127A partially restored in actin filament fence with Arp2/3 complex inhibition, suggesting that actin filament remodeling is both upstream and downstream of YAP activity. These new findings on the cell biology of hESCs reveal a mechanism for cytoskeletal dynamics coordinating cell mechanics to regulate gene expression and facilitate transitions between pluripotency states.

2024-09-11 | GSE276968 | GEO

The Scar/WAVE complex drives normal actin protrusions without the VCA domain, but proline-rich domains are required

Project description:The Scar/WAVE regulatory complex (WRC) is the main catalyst of pseudopod and lamellipodium formation during cell migration. Its actin nucleation activity has been attributed to its ability to activate the Arp2/3 complex through the VCA domain of Scar/WAVE. Here we show in both B16-F1 mouse melanoma cells and Dictyostelium discoideum cells that the WRC with its VCA domain deleted can still induce the formation of morphologically normal actin protrusions. Its function is lost only after further deletion of Scar/WAVE’s (in Dictyostelium cells) or both Abi and WAVE’s (in B16-F1 cells) proline-rich domains. Moreover, mass spectrometry analysis identified BAIAP2 and Vasp (both promotors of actin polymerization) as specific interactors of WRC polyproline domains. Thus we conclude that proline-rich domains play a central role in actin nucleation by concentrating other effectors needed to form actin protrusions. Together, these findings suggest a new mechanism for WRC action independent of the VCA-Arp2/3 interaction.

2024-08-30 | PXD037123 | Pride

mTORC1 and mTORC2 converge on the Arp2/3 complex to promote KrasG12D-induced acinar-to-ductal metaplasia and early pancreatic carcinogenesis

Project description:Oncogenic KrasG12D, a driver mutation of pancreatic ductal adenocarcinoma (PDAC), induces neoplastic transformation of acinar cells through acinar-to-ductal metaplasia (ADM). Here, we show that both functional complexes of mTOR (mechanistic target of rapamycin kinase, mTORC1 and mTORC2) are specifically activated in ADM. Murine models uncover that mTORC1 and mTORC2 cooperate to promote KrasG12D-driven ADM development. Proteomic analyses identify Arp2/3 complex, an actin nucleator, as the common downstream effector: mTORC1 is responsible for the protein synthesis of Rac1 and Arp3 while mTORC2 promotes the Arp2/3 complex activity via Akt/Rac1 signalling. Genetic ablation of Arp2/3 complex completely arrests KrasG12D-driven ADM development. The Arp2/3 complex-mediated y-branching of actin network promotes the basolateral spread of filamentous actin, which is indispensable for acinar cells-initiated carcinogenesis. Induced by oncogenic KrasG12D, ADM is a metaplastic phenotype of acinar cells that requires extensive actin rearrangements. mTORC1 and mTORC2, downstream targets of KrasG12D, have well-established oncogenic functions in PDAC development. The actin-related protein 2/3 (Arp2/3) complex is the first identified actin nucleator. Regarded as textbook knowledge, it is activated by EGFR/Rac1 signalling to promote the polymerisation of branched actin filaments from pre-existing filaments in numerous biological contexts. Hereby, we identify that mTORC1 and mTORC2 attain a dual, yet non-redundant, regulatory role in promoting Arp2/3 complex function, which is responsible for generating basolateral filamentous actin in ADM. Thus, the role of Arp2/3 complex fills up the missing gap between putative oncogenic signals and actin dynamics underlying PDAC initiation.

2021-01-07 | PXD018296 | Pride

MKL1 deficiency results in a severe neutrophil motility defect due to impaired actin polymerization

Project description:Megakaryoblastic leukemia 1 (MKL1) promotes the regulation of essential cell processes, including actin cytoskeletal dynamics by co-activating serum response factor. Recently, the first human case with MKL1 deficiency, leading to a novel primary immunodeficiency, was identified. We report a second family with two siblings with a homozygous frameshift mutation in MKL1. The index case deceased as an infant from progressive and severe pneumonia by Pseudomonas aeruginosa and poor wound healing. The younger sib was preemptively transplanted shortly after birth. The immunodeficiency was marked by a pronounced actin polymerization defect and a strongly reduced motility and chemotactic response by MKL1-deficient neutrophils. Apart from the lack of MKL1, subsequent proteomic and transcriptomic analyses of patient neutrophils revealed actin and several actin-related proteins to be downregulated, confirming a role for MKL1 as transcriptional co-regulator. Degranulation was enhanced upon suboptimal neutrophil activation, while production of reactive oxygen species was normal. Neutrophil adhesion was intact but without proper spreading. The latter could explain the observed failure in firm adherence and transendothelial migration under flow conditions. No apparent defect in phagocytosis and bacterial killing was found. Also monocyte-derived macrophages showed intact phagocytosis; lymphocyte counts and proliferative capacity were normal. Non-hematopoietic primary patient fibroblasts demonstrated defective differentiation into myofibroblasts but normal migration and filamentous actin (F-actin) content, most probably due to compensatory mechanisms of MKL2, which is not expressed in neutrophils. Our findings extend current insight into the severe immune dysfunction in MKL1 deficiency, with cytoskeletal dysfunction and defective extravasation of neutrophils as most prominent features.

2020-03-16 | GSE134644 | GEO

Arp2/3 complex mutants show a pronounced lack of hyphal specific gene expression in Candida albicans

Project description:Candida albicans is a diploid fungal pathogen lacking a defined complete sexual cycle, and thus has been refractory to standard forward genetic analysis. Instead, transcription profiling and reverse genetic strategies based on Saccharomyces cerevisiae have typically been used to link genes to functions. To overcome restrictions inherent in such indirect approaches, we have investigated a forward genetic mutagenesis strategy based on the UAU1 technology. We screened 4700 random insertion mutants for defects in hyphal development, and linked two new genes (ARP2 and VPS52) to hyphal growth. Deleting ARP2 abolished hyphal formation, generated round and swollen yeast phase cells, disrupted cortical actin patches and blocked virulence in mice. The mutants also showed a global lack of induction of hyphae-specific genes upon the yeast-to-hyphae switch. Surprisingly, both arp2Î/Î and arp2Î/Îarp3Î/Î mutants were still able to endocytose FM4-64 and Lucifer Yellow, although as shown by time-lapse movies internalization of FM4-64 was somewhat delayed in mutant cells. Thus the non-essential role of the Arp2/3 complex discovered by forward genetic screening in C. albicans showed that uptake of membrane components from the plasma membrane to vacuolar structures is not dependent on this actin nucleating machinery. By forward genetic screening, we have identified genes that are essential for hyphal formation. One of the hits is the Arp2/3 complex, which is essential for hyphal formation, but not for viability in Candida albicans. To gain insights into cellular processes affected by disrupting Arp2/3 complex functions, we performed transcriptional profiling under yeast growth conditions (YPD at 30Â°C for three hours) or hyphal induction (YPD + 10% FBS at 37Â°C for three hours) and compared transcriptional consequences of deleting ARP2 to MYO5 and SLA2 microarray data sets (Oberholzer et al., 2006).

2010-10-08 | E-GEOD-19565 | biostudies-arrayexpress

Nuclear actin structure regulates chromatin accessibility [ATAC-seq]

Project description:Polymerized B-actin may provide a structural basis for chromatin accessibility and actin transport into the nucleus can guide mesenchymal stem cell (MSC) differentiation. Using MSC, we show that using CK666 to inhibit Arp2/3 directed secondary actin branching results in decreased nuclear actin structure, and significantly alters chromatin access measured with ATACseq at 24 h. The ATAC-seq results due to CK666 are distinct from those caused by cytochalasin D (CytoD), which enhances nuclear actin structure. In addition, nuclear visualization shows Arp2/3 inhibition decreases pericentric H3K9me3 marks. CytoD, alternatively, induces redistribution of H3K27me3 marks centrally. Such alterations in chromatin landscape are consistent with differential gene expression associated with distinctive differentiation patterns. Further, knockdown of the non-enzymatic monomeric actin binding protein, Arp4, leads to extensive chromatin unpacking, but only a modest increase in transcription, indicating an active role for actin-Arp4 in transcription. These data indicate that dynamic actin remodeling can regulate chromatin interactions.

2024-04-12 | GSE242944 | GEO

Comparison of gene expression profiles in naïve WT and Asc-null bone marrow derived dendritic cells

Project description:The adaptor protein ASC contributes to innate immunity through the assembly of caspase-1-activating inflammasome complexes. We demonstrate that ASC plays an inflammasome-independent cell-intrinsic role in adaptive immune cells. Asc-/- mice displayed defective antigen presentation by dendritic cells and lymphocyte migration due to impaired Rac-mediated actin polymerization. Genome-wide analysis showed that ASC, but not Nlrp3 or caspase-1, controls mRNA stability and expression of DOCK2, a guanine nucleotide exchange factor that mediates Rac-dependent signaling in immune cells. DOCK2-deficient dendritic cells showed similar defective antigen uptake as Asc-/- cells. Ectopic expression of DOCK2 in ASC-deficient cells restored Rac-mediated actin polymerization, antigen uptake and chemotaxis. Thus, ASC shapes adaptive immunity independently of inflammasomes by modulating DOCK2-dependent Rac activation and F-actin polymerization in dendritic cells and lymphocytes. Three replicates of naïve WT and three replicates of Asc-/- bone marrow derived dendritic cells were analyzed on the Affymetrix HT MG-430 PM plate array.

2012-07-08 | E-GEOD-30769 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data