scholarly journals The secreted protein DEL-1 activates a β3 integrin–FAK–ERK1/2–RUNX2 pathway and promotes osteogenic differentiation and bone regeneration

2020 ◽  
Vol 295 (21) ◽  
pp. 7261-7273 ◽  
Author(s):  
Da-Yo Yuh ◽  
Tomoki Maekawa ◽  
Xiaofei Li ◽  
Tetsuhiro Kajikawa ◽  
Khalil Bdeir ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Bone Regeneration ◽  
Osteogenic Differentiation ◽  
Secreted Protein ◽  
Dependent Manner ◽  
Point Mutant ◽  
Rgd Motif ◽  
Β3 Integrin ◽  
Defective Bone

The integrin-binding secreted protein developmental endothelial locus-1 (DEL-1) is involved in the regulation of both the initiation and resolution of inflammation in different diseases, including periodontitis, an oral disorder characterized by inflammatory bone loss. Here, using a mouse model of bone regeneration and in vitro cell-based mechanistic studies, we investigated whether and how DEL-1 can promote alveolar bone regeneration during resolution of experimental periodontitis. Compared with WT mice, mice lacking DEL-1 or expressing a DEL-1 variant with an Asp-to-Glu substitution in the RGD motif (“RGE point mutant”), which does not interact with RGD-dependent integrins, exhibited defective bone regeneration. Local administration of DEL-1 or of its N-terminal segment containing the integrin-binding RGD motif, but not of the RGE point mutant, reversed the defective bone regeneration in the DEL-1–deficient mice. Moreover, DEL-1 (but not the RGE point mutant) promoted osteogenic differentiation of MC3T3-E1 osteoprogenitor cells or of primary calvarial osteoblastic cells in a β3 integrin–dependent manner. The ability of DEL-1 to promote in vitro osteogenesis, indicated by induction of osteogenic genes such as the master transcription factor Runt-related transcription factor-2 (Runx2) and by mineralized nodule formation, depended on its capacity to induce the phosphorylation of focal adhesion kinase (FAK) and of extracellular signal-regulated kinase 1/2 (ERK1/2). We conclude that DEL-1 can activate a β3 integrin–FAK–ERK1/2–RUNX2 pathway in osteoprogenitors and promote new bone formation in mice. These findings suggest that DEL-1 may be therapeutically exploited to restore bone lost due to periodontitis and perhaps other osteolytic conditions.

scholarly journals Ligand-dependent repression of the erythroid transcription factor GATA-1 by the estrogen receptor.

1995 ◽  
Vol 15 (6) ◽  
pp. 3147-3153 ◽  
Author(s):  
G A Blobel ◽  
C A Sieff ◽  
S H Orkin
Keyword(s):  
Bone Marrow ◽  
Estrogen Receptor ◽  
Transcription Factor ◽  
Progenitor Cells ◽  
Erythroid Cell ◽  
High Dose ◽  
Dependent Manner ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells

High-dose estrogen administration induces anemia in mammals. In chickens, estrogens stimulate outgrowth of bone marrow-derived erythroid progenitor cells and delay their maturation. This delay is associated with down-regulation of many erythroid cell-specific genes, including alpha- and beta-globin, band 3, band 4.1, and the erythroid cell-specific histone H5. We show here that estrogens also reduce the number of erythroid progenitor cells in primary human bone marrow cultures. To address potential mechanisms by which estrogens suppress erythropoiesis, we have examined their effects on GATA-1, an erythroid transcription factor that participates in the regulation of the majority of erythroid cell-specific genes and is necessary for full maturation of erythrocytes. We demonstrate that the transcriptional activity of GATA-1 is strongly repressed by the estrogen receptor (ER) in a ligand-dependent manner and that this repression is reversible in the presence of 4-hydroxytamoxifen. ER-mediated repression of GATA-1 activity occurs on an artificial promoter containing a single GATA-binding site, as well as in the context of an intact promoter which is normally regulated by GATA-1. GATA-1 and ER bind to each other in vitro in the absence of DNA. In coimmunoprecipitation experiments using transfected COS cells, GATA-1 and ER associate in a ligand-dependent manner. Mapping experiments indicate that GATA-1 and the ER form at least two contacts, which involve the finger region and the N-terminal activation domain of GATA-1. We speculate that estrogens exert effects on erythropoiesis by modulating GATA-1 activity through protein-protein interaction with the ER. Interference with GATA-binding proteins may be one mechanism by which steroid hormones modulate cellular differentiation.

scholarly journals Hypertonicity-induced phosphorylation and nuclear localization of the transcription factor TonEBP

2001 ◽  
Vol 280 (2) ◽  
pp. C248-C253 ◽  
Author(s):  
Stephen C. Dahl ◽  
Joseph S. Handler ◽  
H. Moo Kwon
Keyword(s):  
Transcription Factor ◽  
Nuclear Localization ◽  
Kinase Inhibitors ◽  
Dependent Manner ◽  
Binding Assays ◽  
P38 Inhibitor ◽  
Vitro Binding ◽  
Compatible Osmolytes

The accumulation of compatible osmolytes during osmotic stress is observed in virtually all organisms. In mammals, the hypertonicity-induced expression of osmolyte transporters and synthetic enzymes is conferred by the presence of upstream tonicity-responsive enhancer (TonE) sequences. Recently, we described the cloning and initial characterization of TonE-binding protein (TonEBP), a transcription factor that translocates to the nucleus and associates with TonE sequences in a tonicity-dependent manner. We now report that hypertonicity induces an increase in TonEBP phosphorylation that temporally correlates with increased nuclear localization of the molecule. TonEBP phosphorylation is not affected by a number of kinase inhibitors, including the p38 inhibitor SB-203580. In addition, in vitro binding assays show that the association of TonEBP with TonE sequences is not affected by phosphorylation. Thus TonEBP phosphorylation is an early step in the response of cells to hypertonicity and may be required for nuclear import or retention.

scholarly journals The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression

Oncogene ◽  
2020 ◽  
Vol 39 (44) ◽  
pp. 6841-6855 ◽  
Author(s):  
Christina Jessen ◽  
Julia K. C. Kreß ◽  
Apoorva Baluapuri ◽  
Anita Hufnagel ◽  
Werner Schmitz ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Immune Response ◽  
Transcription Factor ◽  
Prostaglandin E2 ◽  
Innate Immune Response ◽  
Stress Responses ◽  
Melanoma Cells ◽  
Innate Immune ◽  
Dependent Manner

AbstractThe transcription factor NRF2 is the major mediator of oxidative stress responses and is closely connected to therapy resistance in tumors harboring activating mutations in the NRF2 pathway. In melanoma, such mutations are rare, and it is unclear to what extent melanomas rely on NRF2. Here we show that NRF2 suppresses the activity of the melanocyte lineage marker MITF in melanoma, thereby reducing the expression of pigmentation markers. Intriguingly, we furthermore identified NRF2 as key regulator of immune-modulating genes, linking oxidative stress with the induction of cyclooxygenase 2 (COX2) in an ATF4-dependent manner. COX2 is critical for the secretion of prostaglandin E2 and was strongly induced by H2O2 or TNFα only in presence of NRF2. Induction of MITF and depletion of COX2 and PGE2 were also observed in NRF2-deleted melanoma cells in vivo. Furthermore, genes corresponding to the innate immune response such as RSAD2 and IFIH1 were strongly elevated in absence of NRF2 and coincided with immune evasion parameters in human melanoma datasets. Even in vitro, NRF2 activation or prostaglandin E2 supplementation blunted the induction of the innate immune response in melanoma cells. Transcriptome analyses from lung adenocarcinomas indicate that the observed link between NRF2 and the innate immune response is not restricted to melanoma.

scholarly journals Leptin Upregulates the Expression of β3-Integrin, MMP9, HB-EGF, and IL-1β in Primary Porcine Endometrium Epithelial Cells In Vitro

2020 ◽  
Vol 17 (18) ◽  
pp. 6508
Author(s):  
Hongfang Wang ◽  
Jinlian Fu ◽  
Aiguo Wang
Keyword(s):  
Signaling Pathways ◽  
Embryo Implantation ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Reproductive Disorders ◽  
Β3 Integrin ◽  
Epithelium Cells ◽  
Dose Dependent

Obesity has become a global health problem. Research suggests that leptin, a hormone that responds to fat deposition, may be involved in mammalian reproduction; however, its precise role in embryo implantation is poorly understood. Here, primary porcine endometrium epithelium cells (PEECs) were cultured in vitro and used to evaluate the regulatory role of different leptin levels on β3-integrin, MMP9, HB-EGF, and IL-1β, which are, respectively, involved in four critical steps of embryo implantation. Results showed that only 0.01 nM leptin significantly improved β3-integrin mRNA expression (p < 0.05). MMP9 and HB-EGF mRNA expressions were upregulated by 0.10–10.00 nM leptin (p < 0.05). The IL-1β expression level was only increased by 10.00 nM leptin (p < 0.05). β3-integrin, MMP9, HB-EGF, and IL-1β mRNA and protein have a similar fluctuant response to increased leptin. Leptin’s influence on β3-integrin, MMP9, HB-EGF, and IL-1β disappeared when the JAK2, PI(3)K, or MAPK signaling pathways were blocked, respectively. In conclusion, leptin affected porcine implantation by regulating the expression of β3-integrin, MMP9, HB-EGF, and IL-1β in a dose-dependent manner. The signaling pathways of JAK2, PI(3)K, and MAPK may participate in this regulatory process. These findings will contribute to further understanding the mechanisms of reproductive disorders in obesity.

scholarly journals Effect of GHRH and GHRP-2 treatment in vitro on GH secretion and levels of GH, pituitary transcription factor-1, GHRH-receptor, GH-secretagogue-receptor and somatostatin receptor mRNAs in ovine pituitary cells

2004 ◽  
pp. 235-242 ◽  
Author(s):  
M Yan ◽  
M Hernandez ◽  
R Xu ◽  
C Chen
Keyword(s):  
Transcription Factor ◽  
Somatostatin Receptor ◽  
Receptor Subtypes ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Gh Secretion ◽  
Somatostatin Receptor Subtypes ◽  
Transcription Factor 1

OBJECTIVE: Growth hormone (GH)-releasing hormone (GHRH) and GH-releasing peptides (GHRPs) stimulate the release of GH through their specific receptors on somatotropes. Combined GHRH and GHRP administration causes a synergistic GH release in vivo by an unknown mechanism. The current study focuses on the direct action of GHRH and GHRP on several molecular targets in somatotropes. DESIGN AND METHODS: To clarify the mechanism of action, ovine somatotropes were used to measure the expression of mRNAs encoding for GH, pituitary transcription factor-1 (Pit-1), GH-secretagogue receptor (GHS-R), GHRH-R, somatostatin receptor subtypes (sst-1 and sst-2) and GH release after GHRH and GHRP-2 treatment for 0.5, 1, 1.5 and 2 h. RESULTS: GHRH (10 nM), GHRP-2 (100 nM) and combined GHRH-GHRP-2 increased the levels of GH mRNA and GH release from 0.5 to 2 h in a time-dependent manner. The levels of Pit-1, GHRH-R and GHS-R mRNA were increased after 0.5 h treatment of cells with GHRH and GHRP-2. The levels of sst-1 but not sst-2 mRNA were significantly increased after 0.5 and 1 h of GHRH treatment. In contrast, both sst-1 and sst-2 mRNA expression was inhibited after 0.5-2 h of GHRP treatment. CONCLUSIONS: These data demonstrate a direct in vitro modification of ovine somatotropes by GHRH and GHRP-2 resulting in altered GHRH-R, GHS-R, Pit-1, sst-1, sst-2 and GH gene expression; this may underlie the regulatory action of GHRH and GHRP-2 on GH secretion.

scholarly journals Ligand-dependent and -independent activation of the transcription factor γRF-1 in a cell-free system

1995 ◽  
Vol 310 (2) ◽  
pp. 461-467 ◽  
Author(s):  
C A Feghali ◽  
T M Wright
Keyword(s):  
Transcription Factor ◽  
Tyrosine Phosphatase ◽  
Cell Fractionation ◽  
Dependent Manner ◽  
Sodium Orthovanadate ◽  
Ifn Gamma ◽  
Free System ◽  
Cell Free System ◽  
A Cell

gamma RF-1 is a recently identified transcription factor induced by interferon-gamma (IFN-gamma) which binds to a unique palindromic enhancer, gamma RE-1, in the promoter of the mig gene. This paper describes the ligand-dependent and ligand-independent activation of gamma RF-1 in a cell-free system. gamma RF-1 activity was induced by IFN-gamma in a time-dependent manner from 5 to 60 min in lysates prepared from the human monocytic leukaemia line THP-1 and the human epidermoid carcinoma line A431. The activation of gamma RF-1 in vitro required both ATP and an inhibitor of tyrosine phosphatases (sodium orthovanadate or pervanadate). In the presence of limiting concentrations (micromolar) of ATP, activation was also dependent upon stimulation with IFN-gamma, whereas at millimolar concentrations of ATP, gamma RF-1 was activated by either sodium orthovanadate or pervanadate in the absence of ligand. Based on cell fractionation studies, both membrane and cytosol components were essential for activation of gamma RF-1 in vitro. Consistent with a role for one or more tyrosine kinases in the activation of gamma RF-1, its DNA binding activity was blocked by monoclonal anti-phosphotyrosine antibodies and by the tyrosine kinase inhibitors genistein, lavendustin A and herbimycin A. A comparison with recently described pathways of IFN-mediated transcription factor regulation indicates that the in vitro activation of gamma RF-1 is unique, requiring both membrane and cytosol fractions and inhibition of endogenous tyrosine phosphatase activity.

Methylation of RUNX1 by the Nuclear PRMT5/COPR5 Complex Regulates Its Cellular Location in Leukemia Cells,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3403-3403
Author(s):  
Xinyang Zhao ◽  
Ly P. Vu ◽  
Fabiana Perna ◽  
Fan Liu ◽  
Hao Xu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Arginine Methylation ◽  
Binding Domain ◽  
Dependent Manner ◽  
Dna Binding Domain ◽  
Sm Proteins ◽  
Differentiation Potential ◽  
Hematopoietic Stem

Abstract Abstract 3403 RUNX1 is a transcription factor that is required for definitive hematopoietic development, and helps regulate long term hematopoietic stem cell self-renewal, platelet production, and lymphocyte development during adult hematopoiesis. RUNX1 is known to be modified via phosphorylation, acetylation, ubiquitination and methylation, for example on R208 and R210 by PRMT1, which activates its activating function. We continue to investigate how the methylation of RUNX1 by other protein arginine methyl transferases (PRMTs) regulates its function. Loop 9 of the DNA binding domain (the Runt domain) of RUNX1 contains an SGRGK sequence that is also present on the tails of histone H2A and H4. The histone tails of H4 and H2A can be methylated by a purified PRMT5 complex in vitro. An enzymatically active in vitro PRMT5 complex capable of methylating histones and SM proteins requires two subunits: both PRMT5 and MEP50, a WD 40 repeat domain protein. Nevertheless, this purified PRMT5/MEP50 complex cannot methylate the DNA binding domain of the RUNX1 protein in vitro. We show that RUNX1 also can be symmetrically methylated at R142 within the SGRGK motif in vitro by a nuclear PRMT5/MEP50 complex which also contains COPR5. We show after RUNX1 is methylated on R142 within the nucleus of HEL cells, RUNX1 is exported to the cytoplasm in a CRM1 dependent manner, as the export of methylated RUNX1 is blocked by lemptomycin B. CRM1 interacts with PRMT5, supporting that PRMT5 mediated arginine methylation tags protein for nuclear export. Therefore, PRMT5 not only involves in epigenetic regulation by methylation of histones but also it can directly controls the level of transcription factor proteins within the nucleus. Polycytocemia Vera patients who express the Jak2V617F mutation have low PRMT5 activity due to JAK2V617F mediated PRMT5 phosphorylation (Liu et al 2011). How Jak2 signaling affects RUNX1 methylation and RUNX1 localization within the nucleus is still under investigation. By controlling the amount of RUNX1 available within the cell nucleus, PRMT5 may regulate lineage differentiation potential and growth potential of hematopoietic stem and progenitor cells. The nuclear localization of RUNX1 can be changed through post translational modification such as arginine methylation in addition to point mutations and translocations involving RUNX1 found patients with leukemia and pre-leukemic diseases. Disclosures: No relevant conflicts of interest to declare.

scholarly journals MiR-144-5p, an exosomal miRNA from bone marrow-derived macrophage in type 2 diabetes, impairs bone fracture healing via targeting Smad1

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dong Zhang ◽  
Yifan Wu ◽  
Zonghuan Li ◽  
Hairen Chen ◽  
Siyuan Huang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Fracture Healing ◽  
Bone Regeneration ◽  
Osteogenic Differentiation ◽  
Fracture Repair ◽  
Osteogenic Potential ◽  
Patients With Diabetes ◽  
The Impact

Abstract Background Patients with diabetes have an increased risk of nonunion and delayed union of fractures. Macrophages have been shown as a key player in diabetic complications. However, it remains obscure how diabetic milieu affects macrophage-derived exosomes and its implications on osteogenic differentiation of BMSCs. In this study, we aim to define the impact of diabetic milieu on macrophage-derived exosomes, role of extracellular vesicles in intercellular communication with BMSCs, and subsequent effects on osteogenic differentiation and fracture repair. Results The osteogenic potential and the ability of fracture repair of exosomes derived from diabetic bone marrow-derived macrophages (dBMDM-exos) were revealed to be lower, as compared with non-diabetic bone marrow-derived macrophages (nBMDM-exos) in vitro and in vivo. Interestingly, miR-144-5p levels were sharply elevated in dBMDM-exos and it could be transferred into BMSCs to regulate bone regeneration by targeting Smad1. In addition, the adverse effects of dBMDM-exos on the osteogenic potential and the ability of fracture repair were reversed through the suppression of miR-144-5p inhibition in vitro and vivo. Conclusions The results demonstrated an important role of exosomal miR-144-5p in bone regeneration, offering insight into developing new strategy for the improvement of fracture healing in patients with diabetes mellitus. Graphic Abstract

Sign in / Sign up

Export Citation Format

Share Document