scholarly journals Lamin A/C mutation associated with lipodystrophy influences adipogenic differentiation of stem cells through interaction with Notch signaling

2018 ◽  
Vol 96 (3) ◽  
pp. 342-348 ◽  
Author(s):  
K. Perepelina ◽  
R. Dmitrieva ◽  
E. Ignatieva ◽  
A. Borodkina ◽  
A. Kostareva ◽  
...  

Lamins A and C are involved in many cellular functions, owing to its ability to bind chromatin and transcription factors and affect their properties. Mutations of the LMNA gene encoding lamin A/C affect differentiation capacity of stem cells. However, the signaling pathways involved in interactions with lamins during cellular differentiation remain unclear. Lipodystrophy associated with LMNA mutation R482L causes loss of fat tissue. In this study we investigated the role of LMNA mutation R482L in modulating Notch signaling activity in the adipogenic differentiation of mesenchymal stem cells. Notch was activated using lentiviral Notch intracellular domain. Activation of Notch was estimated through the expression of Notch-responsive genes by qPCR and by activation of a luciferase CSL-reporter construct. The effect of LMNA mutation on Notch activation and adipogenic differentiation was analyzed in cells bearing lentiviral LMNA WT or LMNA R482L. We show that, when Notch is activated, LMNA R482L contributes to down-regulation of Notch activation in undifferentiated and differentiated cells, and decreases adipogenic differentiation. Thus, lamin A/C interacts with Notch signaling, thereby influencing cellular differentiation, and point mutation in LMNA could halt this interaction.

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Marina Cardano ◽  
Jacopo Zasso ◽  
Luca Ruggiero ◽  
Giuseppina Di Giacomo ◽  
Matteo Marcatili ◽  
...  

Epsins are part of the internalization machinery pivotal to control clathrin-mediated endocytosis. Here, we report that epsin family members are expressed in mouse embryonic stem cells (mESCs) and that epsin1/2 knockdown alters both mESC exits from pluripotency and their differentiation. Furthermore, we show that epsin1/2 knockdown compromises the correct polarization and division of mESC-derived neural progenitors and their conversion into expandable radial glia-like neural stem cells. Finally, we provide evidence that Notch signaling is impaired following epsin1/2 knockdown and that experimental restoration of Notch signaling rescues the epsin-mediated phenotypes. We conclude that epsins contribute to control mESC exit from pluripotency and allow their neural differentiation by appropriate modulation of Notch signaling.


2008 ◽  
Vol 181 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Eran Meshorer ◽  
Yosef Gruenbaum

Specific mutations in the human gene encoding lamin A or in the lamin A–processing enzyme, Zmpste24, cause premature aging. New data on mice and humans suggest that these mutations affect adult stem cells by interfering with the Notch and Wnt signaling pathways.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1923-1923
Author(s):  
Fernando Ugarte ◽  
Martin F. Ryser ◽  
Sebastian Thieme ◽  
Martin Bornhaeuser ◽  
Sebastian Brenner

Abstract Notch, expressed on hematopoietic progenitors plays a crucial role in hematopoiesis. Mesenchymal stem cells (MSC) express both, Notch and its ligand Jagged and are known to support self renewal of hematopoietic progenitors via cell-cell contact and cytokine secretion. The Jagged/Notch signaling pathway has been implicated in the differentiation process of MSC, however it is not completely understood and current observations are contradictory. In order to analyze the effect of Notch signaling on human MSC differentiation we constructed lentiviral vectors that contained either the GFP-marker gene, hJagged1 IRES GFP, hNotch1 intracellular domain (NICD) IRES GFP or a gene fusion between dominant negative Mastermind1 (MAML1dn - inhibitor of Notch signaling) and the Cherry reporter gene. Primary hMSC that were obtained from bone marrow of 3 different donors were transduced with respective lentivirus vectors to greater than 98%. After exposure to adipogenic and osteogenic differentiation stimuli hMSC differentiation was quantified by Alizarin red or oil red staining, alkaline phosphatase (AP) activity and expression levels of adipogenic or osteogenic markers by Real-time PCR. Jagged1 transduced hMSC demonstrated enhanced calcium phosphate deposits and enhanced AP activity and expression levels in osteogenic differentiation medium, while adipogenic differentiation was strongly inhibited as quantified by oil red staining and low mRNA expression of genes upregulated during adipogenic differentiation (pprY, Fabp4). Similarly, overexpression of NICD induced strong and rapid osteogenic differentiation while inhibiting adipogenic differentiation and reducing cell viability. Moreover, NICD overexpression upregulates the expression of endogenous Jagged1 up to 5-fold. Inhibition of Notch signaling via overexpression of MAML1dn partially blocked the effect of hJagged1 and NICD in co-transduction experiments. In another approach MSC samples obtained from 20 donors with various osteogenic differentiation potential as measured by AP activity were analyzed for Notch1 and Jagged1 expression. While there was no correlation between AP activity and Notch1 levels we observed a significant positive correlation for AP activity and Jagged1 expression. In summary, our data strongly suggest that increased Jagged/Notch signaling enhances the osteogenic differentiation of hMSC while inhibiting their adipogenic fate.


Author(s):  
Su-Jin Heo ◽  
Nandan L. Nerurkar ◽  
Tristan P. Driscoll ◽  
Robert L. Mauck

Mesenchymal stem cells (MSCs) are a promising cell source for tissue engineering applications, given their ease of isolation and multi-potential differentiation capacity [1]. Passive and active mechanical signals can direct MSC lineage commitment [2], however, the subcellular machinery that translates physical cues to biologic response remains unclear. Direct deformation of the nucleus may influence differentiation by inducing mechanical reorganization of nuclear chromatin. Because the nuclei of differentiated cells are stiffer than progenitor cells [3], it is possible that such mechanoregulatory mechanisms vary with differentiation state. Lamin A/C is a filamentous protein that largely defines nuclear shape, size and stiffness [3]. Recent work suggests that Lamin A/C also regulates chromatin organization and transcriptional activity [4]. Recently, we have developed an in vitro system to direct the functional differentiation of MSCs into fibrochondrocytes, using electrospun polymeric nanofiber substrates [5]. Alignment of nanofibers directs cell alignment, allowing external forces to be applied uniformly along the long axes of cells, emulating the mechanical microenvironment experienced by embryonic progenitors during fibrous tissue morphogenesis [6]. We have noted, however, that as MSCs undergo fibrochondrogenesis, translation of scaffold deformation to nuclear deformation is attenuated [7]. From those studies, it was not clear whether this was due to changes in cellular mechanics or to accretion of extracellular matrix during differentiation. Thus the objective of the present work was to specifically identify how fibrochondrogenesis of MSCs on aligned nanofibrous scaffolds alters nuclear mechanics and mechanoreception, and further to ascertain whether mechanical stimulation alone can elicit similar mechanoregulatory changes.


2011 ◽  
Vol 208 (4) ◽  
pp. 677-688 ◽  
Author(s):  
Tae-Hee Kim ◽  
Ramesh A. Shivdasani

The mammalian adult gastric epithelium self-renews continually through the activity of stem cells located in the isthmus of individual gland units. Mechanisms facilitating stomach stem and progenitor cell homeostasis are unknown. Here, we show that Notch signaling occurs in the mouse stomach epithelium during development and becomes restricted mainly to the isthmus in adult glands, akin to its known localization in the proliferative compartment of intestinal villi. Using genetic and chemical inhibition, we demonstrate that Notch signaling is required to maintain the gastric stem cell compartment. Activation of Notch signaling in lineage-committed stomach epithelial cells is sufficient to induce dedifferentiation into stem and/or multipotential progenitors that populate the mucosa with all major cell types. Prolonged Notch activation within dedifferentiated parietal cells eventually enhances cell proliferation and induces adenomas that show focal Wnt signaling. In contrast, Notch activation within native antral stomach stem cells does not affect cell proliferation. These results establish a role for Notch activity in the foregut and highlight the importance of cellular context in gastric tumorigenesis.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 2539-2539
Author(s):  
Agamemnon A. Epenetos ◽  
Spyros Stylianou

2539 Background: Current treatments often fail to cure cancer. It has been shown (JCO, 26, June 10, 2008) that Cancer Stem Cells, (CSCs), are responsible for the initiation, metastasis and recurrence of many cancers and may be a key reason for the failure of current therapies.The NOTCH pathway is an important pathway in the development of many tumors ,and cancer stem cells in particular. Methods: We have generated genetically and synthetically a hybrid protein (Antp-DNMAML) .consisting of the truncated version of MastermindElike (MAML) that behaves in a dominant negative (DN) fashion inhibiting Notch activation, and the cell penetrating peptide Antennapedia (Antp). Results: It is demonstrated that Antp-DNMAML translocates into the nucleus and suppresses Notch activation. Attenuation of Notch signaling with AntpEDNMAML reverts the transformed phenotype, inhibits the anchorageEdependent growth, induces self contact inhibition and apoptosis in highly tumorigenic epithelial human breast cancer cells. More significantly, we provide direct evidence that inhibiting Notch signaling at the transcriptional level with the Antp-MAML protein ,suppresses the expression of downstream Notch targets, induces tumor cell apoptosis, and inhibits or eliminates human tumor growth in nude mice, without organ or systemic toxicity. Conclusions: Intracellular delivery of dominant-negative transcription complex proteins using the Antp platform is a new and specific approach for cancer therapy.


2017 ◽  
Vol 216 (9) ◽  
pp. 2731-2743 ◽  
Author(s):  
Anja Oldenburg ◽  
Nolwenn Briand ◽  
Anita L. Sørensen ◽  
Inswasti Cahyani ◽  
Akshay Shah ◽  
...  

Mutations in the Lamin A/C (LMNA) gene-encoding nuclear LMNA cause laminopathies, which include partial lipodystrophies associated with metabolic syndromes. The lipodystrophy-associated LMNA p.R482W mutation is known to impair adipogenic differentiation, but the mechanisms involved are unclear. We show in this study that the lamin A p.R482W hot spot mutation prevents adipogenic gene expression by epigenetically deregulating long-range enhancers of the anti-adipogenic MIR335 microRNA gene in human adipocyte progenitor cells. The R482W mutation results in a loss of function of differentiation-dependent lamin A binding to the MIR335 locus. This impairs H3K27 methylation and instead favors H3K27 acetylation on MIR335 enhancers. The lamin A mutation further promotes spatial clustering of MIR335 enhancer and promoter elements along with overexpression of the MIR355 gene after adipogenic induction. Our results link a laminopathy-causing lamin A mutation to an unsuspected deregulation of chromatin states and spatial conformation of an miRNA locus critical for adipose progenitor cell fate.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Stachecka ◽  
Pawel A. Kolodziejski ◽  
Magdalena Noak ◽  
Izabela Szczerbal

AbstractA characteristic spatial distribution of the main chromatin fractions is observed in most mammalian cell nuclei, with euchromatin localized in the interior and heterochromatin at the nuclear periphery. It has been shown that interactions of heterochromatin with the nuclear lamina are necessary to establish this conventional architecture. Adipocytes are specific cells in which a reduction in lamin A/C expression is observed. We hypothesize that the loss of lamin A/C during adipogenic differentiation of mesenchymal stem cells (MSCs) may be associated with the reorganization of the main classes of chromatin in the nucleus. Thus, in this study, we examine the abundance and nuclear distribution of selected heterochromatin (H3K9me3, H3K27me3 and H4K20me3) and euchromatin (H4K8ac, H3K4me3 and H3K9ac) histone marks during in vitro adipogenesis, using the pig as a model organism. We found that not only did the expression of lamin A/C decrease in our differentiation system, but so did the expression of lamin B receptor (LBR). The level of two heterochromatin marks, H3K27me3 and H4K20me3, increased during differentiation, while no changes were observed for H3K9me3. The levels of two euchromatin histone marks, H4K8ac and H3K9ac, were significantly higher in adipocytes than in undifferentiated cells, while the level of H3K4me3 did not change significantly. The spatial distribution of all the examined histone marks altered during in vitro adipogenesis. H3K27me3 and H4K20me3 moved towards the nuclear periphery and H3K9me3 localized preferentially in the intermediate part of adipocyte nuclei. The euchromatin marks H3K9ac and H3K4me3 preferentially occupied the peripheral part of the adipocyte nuclei, while H4K8ac was more evenly distributed in the nuclei of undifferentiated and differentiated cells. Analysis of the nuclear distribution of repetitive sequences has shown their clustering and relocalization toward nuclear periphery during differentiation. Our study shows that dynamic changes in the abundance and nuclear distribution of active and repressive histone marks take place during adipocyte differentiation. Nuclear reorganization of heterochromatin histone marks may allow the maintenance of the nuclear morphology of the adipocytes, in which reduced expression of lamin A/C and LBR is observed.


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