scholarly journals ALK5- and TGFBR2-independent role of ALK1 in the pathogenesis of hereditary hemorrhagic telangiectasia type 2

Blood ◽  
2008 ◽  
Vol 111 (2) ◽  
pp. 633-642 ◽  
Author(s):  
Sung O. Park ◽  
Young Jae Lee ◽  
Tsugio Seki ◽  
Kwon-Ho Hong ◽  
Naime Fliess ◽  
...  
Keyword(s):  
Hereditary Hemorrhagic Telangiectasia ◽  
Transforming Growth Factor ◽  
Vascular Malformations ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Conditional Deletion ◽  
Pathologic Features

ALK1 belongs to the type I receptor family for transforming growth factor-β family ligands. Heterozygous ALK1 mutations cause hereditary hemorrhagic telangiectasia type 2 (HHT2), a multisystemic vascular disorder. Based largely on in vitro studies, TGF-β1 has been considered as the most likely ALK1 ligand related to HHT, yet the identity of the physiologic ALK1 ligand remains controversial. In cultured endothelial cells, ALK1 and another TGF-β type I receptor, ALK5, regulate angiogenesis by controlling TGF-β signal transduction, and ALK5 is required for ALK1 signaling. However, the extent to which such interactions between these 2 receptors play a role in pathogenesis of HHT is unknown. We directly addressed these issues in vivo by comparing the phenotypes of mice in which the Alk1, Alk5, or Tgfbr2 gene was conditionally deleted in restricted vascular endothelia using a novel endothelial Cre transgenic line. Alk1-conditional deletion resulted in severe vascular malformations mimicking all pathologic features of HHT. Yet Alk5- or Tgfbr2-conditional deletion in mice, or Alk5 inhibition in zebrafish, did not affect vessel morphogenesis. These data indicate that neither ALK5 nor TGFBR2 is required for ALK1 signaling pertinent to the pathogenesis of HHT and suggest that HHT might not be a TGF-β subfamily disease.

scholarly journals High doses of TGF-β potently suppress type I collagen via the transcription factor CUX1

2011 ◽  
Vol 22 (11) ◽  
pp. 1836-1844 ◽  
Author(s):  
Maria Fragiadaki ◽  
Tetsurou Ikeda ◽  
Abigail Witherden ◽  
Roger M Mason ◽  
David Abraham ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Interstitial Fibrosis ◽  
Transforming Growth Factor Β ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Type I ◽  
Aberrant Expression

Transforming growth factor-β (TGF-β) is an inducer of type I collagen, and uncontrolled collagen production leads to tissue scarring and organ failure. Here we hypothesize that uncovering a molecular mechanism that enables us to switch off type I collagen may prove beneficial in treating fibrosis. For the first time, to our knowledge, we provide evidence that CUX1 acts as a negative regulator of TGF-β and potent inhibitor of type I collagen transcription. We show that CUX1, a CCAAT displacement protein, is associated with reduced expression of type I collagen both in vivo and in vitro. We show that enhancing the expression of CUX1 results in effective suppression of type I collagen. We demonstrate that the mechanism by which CUX1 suppresses type I collagen is through interfering with gene transcription. In addition, using an in vivo murine model of aristolochic acid (AA)-induced interstitial fibrosis and human AA nephropathy, we observe that CUX1 expression was significantly reduced in fibrotic tissue when compared to control samples. Moreover, silencing of CUX1 in fibroblasts from kidneys of patients with renal fibrosis resulted in increased type I collagen expression. Furthermore, the abnormal CUX1 expression was restored by addition of TGF-β via the p38 mitogen-activated protein kinase pathway. Collectively, our study demonstrates that modifications of CUX1 expression lead to aberrant expression of type I collagen, which may provide a molecular basis for fibrogenesis.

scholarly journals A Polysaccharide Isolated from Codonopsis pilosula with Immunomodulation Effects Both In Vitro and In Vivo

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3632 ◽  
Author(s):  
Yuan-Feng Zou ◽  
Yan-Yun Zhang ◽  
Yu-Ping Fu ◽  
Kari Inngjerdingen ◽  
Berit Paulsen ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Immunoglobulin A ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Immunomodulating Activity ◽  
Acidic Polysaccharide ◽  
Codonopsis Pilosula ◽  
Intestinal Immune System

In this study, an acidic polysaccharide from Codonopsis pilosula Nannf. var. modesta (Nannf.) L. T. Shen (WCP-I) and its main fragment, WCP-Ia, obtained after pectinase digestion, were structurally elucidated and found to consist of a rhamnogalacturonan I (RG-I) region containing both arabinogalactan type I (AG-I) and type II (AG-II) as sidechains. They both expressed immunomodulating activity against Peyer’s patch cells. Endo-1,4-β-galactanase degradation gave a decrease of interleukine 6 (IL-6) production compared with native WCP-I and WCP-Ia, but exo-α-l-arabinofuranosidase digestion showed no changes in activity. This demonstrated that the stimulation activity partly disappeared with removal of β-d-(1→4)-galactan chains, proving that the AG-I side chain plays an important role in immunoregulation activity. WCP-Ia had a better promotion effect than WCP-I in vivo, shown through an increased spleen index, higher concentrations of IL-6, transforming growth factor-β (TGF-β), and tumor necrosis factor-α (TNF-α) in serum, and a slight increment in the secretory immunoglobulin A (sIgA) and CD4+/CD8+ T lymphocyte ratio. These results suggest that β-d-(1→4)-galactan-containing chains in WCP-I play an essential role in the expression of immunomodulating activity. Combining all the results in this and previous studies, the intestinal immune system might be the target site of WCP-Ia.

scholarly journals Transforming Growth Factor-β Receptors Interact with AP2 by Direct Binding to β2 Subunit

2002 ◽  
Vol 13 (11) ◽  
pp. 4001-4012 ◽  
Author(s):  
Diying Yao ◽  
Marcelo Ehrlich ◽  
Yoav I. Henis ◽  
Edward B. Leof
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Coated Pits ◽  
Wide Range ◽  
Cytoplasmic Tails ◽  
Direct Binding

Transforming growth factor-β (TGF-β) superfamily members regulate a wide range of biological processes by binding to two transmembrane serine/threonine kinase receptors, type I and type II. We have previously shown that the internalization of these receptors is inhibited by K+ depletion, cytosol acidification, or hypertonic medium, suggesting the involvement of clathrin-coated pits. However, the involvement of the clathrin-associated adaptor complex AP2 and the identity of the AP2 subunit that binds the receptors were not known. Herein, we have studied these issues by combining studies on intact cells with in vitro assays. Using fluorescence photobleaching recovery to measure the lateral mobility of the receptors on live cells (untreated or treated to alter their coated pit structure), we demonstrated that their mobility is restricted by interactions with coated pits. These interactions were transient and mediated through the receptors' cytoplasmic tails. To measure direct binding of the receptors to specific AP2 subunits, we used yeast two-hybrid screens and in vitro biochemical assays. In contrast to most other plasma membrane receptors that bind to AP2 via the μ2 subunit, AP2/TGF-β receptor binding was mediated by a direct interaction between the β2-adaptin N-terminal trunk domain and the cytoplasmic tails of the receptors; no binding was observed to the μ2, α, or ς2 subunits of AP2 or to μ1 of AP1. The data uniquely demonstrate both in vivo and in vitro the ability of β2-adaptin to directly couple TGF-β receptors to AP2 and to clathrin-coated pits, providing the first in vivo evidence for interactions of a transmembrane receptor with β2-adaptin.

scholarly journals Functionally diverse heteromeric traps for ligands of the transforming growth factor-β superfamily

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ravindra Kumar ◽  
Asya V. Grinberg ◽  
Huiming Li ◽  
Tzu-Hsing Kuo ◽  
Dianne Sako ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Systematic Analysis ◽  
Activin Receptor ◽  
Naturally Occurring ◽  
Functionally Diverse

AbstractLigands of the transforming growth factor-β (TGF-β) superfamily are important targets for therapeutic intervention but present challenges because they signal combinatorially and exhibit overlapping activities in vivo. To obtain agents capable of sequestering multiple TGF-β superfamily ligands with novel selectivity, we generated soluble, heterodimeric ligand traps by pairing the extracellular domain (ECD) of the native activin receptor type IIB (ActRIIB) alternately with the ECDs of native type I receptors activin receptor-like kinase 4 (ALK4), ALK7, or ALK3. Systematic analysis of these heterodimeric constructs by surface plasmon resonance, and comparison with their homodimeric counterparts, revealed that each type I receptor partner confers a distinct ligand-binding profile to the heterodimeric construct. Additional characterization in cell-based reporter gene assays confirmed that the heterodimeric constructs possessed different profiles of signaling inhibition in vitro, which translated into altered patterns of pharmacological activity when constructs were administered systemically to wild-type mice. Our results detail a versatile platform for the modular recombination of naturally occurring receptor domains, giving rise to inhibitory ligand traps that could aid in defining the physiological roles of TGF-β ligand sets or be directed therapeutically to human diseases arising from dysregulated TGF-β superfamily signaling.

In vivo inosine protects alveolar epithelial type 2 cells against hyperoxia-induced DNA damage through MAP kinase signaling

2005 ◽  
Vol 288 (3) ◽  
pp. L569-L575 ◽  
Author(s):  
S. Buckley ◽  
L. Barsky ◽  
K. Weinberg ◽  
D. Warburton
Keyword(s):  
Dna Damage ◽  
Transforming Growth Factor ◽  
Mapk Pathway ◽  
Alveolar Epithelium ◽  
Transforming Growth Factor Β ◽  
Alveolar Epithelial ◽  
Hyperoxic Exposure

Inosine, a naturally occurring purine with anti-inflammatory properties, was assessed as a possible modulator of hyperoxic damage to the pulmonary alveolar epithelium. Rats were treated with inosine, 200 mg/kg ip, twice daily during 48-h exposure to >90% oxygen. The alveolar epithelial type 2 cells (AEC2) were then isolated and cultured. AEC2 isolated from inosine-treated hyperoxic rats had less DNA damage and had increased antioxidant status compared with AEC2 from hyperoxic rats. Inosine treatment during hyperoxia also reduced the proportion of AEC2 in S and G2/M phases of the cell cycle and increased levels of the DNA repair enzyme 8-oxoguanine DNA glycosylase. Bronchoalveolar lavage (BAL) recovered from hyperoxic, inosine-treated rats contained threefold higher levels of active transforming growth factor-β than BAL from rats exposed to hyperoxia alone, and Smad2 was activated in AEC2 isolated from these animals. ERK1/2 was activated both in freshly isolated and 24-h-cultured AEC2 by in vivo inosine treatment, whereas blockade of the MAPK pathway in vitro reduced the protective effect of in the vivo inosine treatment. Together, the data suggest that inosine treatment during hyperoxic exposure results in protective signaling mediated through pathways downstream of MEK. Thus inosine may deserve further evaluation for its potential to reduce hyperoxic damage to the pulmonary alveolar epithelium.

scholarly journals mTOR inhibitors potentially reduce TGF-β2-induced fibrogenic changes in trabecular meshwork cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nozomi Igarashi ◽  
Megumi Honjo ◽  
Makoto Aihara
Keyword(s):  
Trabecular Meshwork ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Mtor Inhibitors ◽  
In Vivo Model ◽  
Type I ◽  
Fibrotic Response ◽  
Alpha Smooth Muscle Actin

AbstractWe examined the effects of mTOR inhibitors on the fibrotic response induced by transforming growth factor-beta2 (TGF-β2) in cultured human trabecular meshwork (hTM) cells. TGF-β2-induced expression of fibronectin, collagen type I, alpha 1 chain (COL1A1), and alpha-smooth muscle actin (αSMA) in hTM cells was examined in the presence or absence of mTOR inhibitors using quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. The migration rates of hTM cells were examined in the presence of TGF-β2 with or without mTOR inhibitors. An in vitro study showed that the expression of fibronectin, COL1A1, and αSMA was upregulated by TGF-β2 treatment of hTM cells; such upregulation was significantly suppressed by mTOR inhibitors. The inhibitors significantly reduced the migration rate of TGF-β2-stimulated hTM cells. mTOR inhibitors may usefully reduce the fibrotic response of hTM cells and we may have to explore if it is also effective in in vivo model.

scholarly journals Temporal transcriptomic profiling reveals dynamic changes in gene expression of Xenopus animal cap upon activin treatment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yumeko Satou-Kobayashi ◽  
Jun-Dal Kim ◽  
Akiyoshi Fukamizu ◽  
Makoto Asashima
Keyword(s):  
Time Course ◽  
Transforming Growth Factor ◽  
Transcriptome Profiling ◽  
Transforming Growth Factor Β ◽  
Activin A ◽  
Cytokine Signaling ◽  
Molecular Characteristics ◽  
Transcriptional Dynamics

AbstractActivin, a member of the transforming growth factor-β (TGF-β) superfamily of proteins, induces various tissues from the amphibian presumptive ectoderm, called animal cap explants (ACs) in vitro. However, it remains unclear how and to what extent the resulting cells recapitulate in vivo development. To comprehensively understand whether the molecular dynamics during activin-induced ACs differentiation reflect the normal development, we performed time-course transcriptome profiling of Xenopus ACs treated with 50 ng/mL of activin A, which predominantly induced dorsal mesoderm. The number of differentially expressed genes (DEGs) in response to activin A increased over time, and totally 9857 upregulated and 6663 downregulated DEGs were detected. 1861 common upregulated DEGs among all Post_activin samples included several Spemann’s organizer genes. In addition, the temporal transcriptomes were clearly classified into four distinct groups in correspondence with specific features, reflecting stepwise differentiation into mesoderm derivatives, and a decline in the regulation of nuclear envelop and golgi. From the set of early responsive genes, we also identified the suppressor of cytokine signaling 3 (socs3) as a novel activin A-inducible gene. Our transcriptome data provide a framework to elucidate the transcriptional dynamics of activin-driven AC differentiation, reflecting the molecular characteristics of early normal embryogenesis.

scholarly journals Active immunization against the proregions of GDF9 or BMP15 alters ovulation rate and litter size in mice

Reproduction ◽  
2012 ◽  
Vol 143 (2) ◽  
pp. 195-201 ◽  
Author(s):  
C Joy McIntosh ◽  
Steve Lawrence ◽  
Peter Smith ◽  
Jennifer L Juengel ◽  
Kenneth P McNatty
Keyword(s):  
Litter Size ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cross Reactivity ◽  
Full Length ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Immunization Group

The transforming growth factor β (TGFB) superfamily proteins bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), are essential for mammalian fertility. Recent in vitro evidence suggests that the proregions of mouse BMP15 and GDF9 interact with their mature proteins after secretion. In this study, we have actively immunized mice against these proregions to test the potential in vivo roles on fertility. Mice were immunized with either N- or C-terminus proregion peptides of BMP15 or GDF9, or a full-length GDF9 proregion protein, each conjugated to keyhole limpet hemocyanin (KLH). For each immunization group, ovaries were collected from ten mice for histology after immunization, while a further 20 mice were allowed to breed and litter sizes were counted. To link the ovulation and fertility data of these two experimental end points, mice were joined during the time period identified by histology as being the ovulatory period resulting in to the corpora lutea (CL) counted. Antibody titers in sera increased throughout the study period, with no cross-reactivity observed between BMP15 and GDF9 sera and antigens. Compared with KLH controls, mice immunized with the N-terminus BMP15 proregion peptide had ovaries with fewer CL (P<0.05) and produced smaller litters (P<0.05). In contrast, mice immunized with the full-length GDF9 proregion not only had more CL (P<0.01) but also had significantly smaller litter sizes (P<0.01). None of the treatments affected the number of antral follicles per ovary. These findings are consistent with the hypothesis that the proregions of BMP15 and GDF9, after secretion by the oocyte, have physiologically important roles in regulating ovulation rate and litter size in mice.

Abstract 17285: A Selective Transforming Growth Factor-β and Growth Differentiation Factor-15 Ligand Trap Attenuates Pulmonary Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lai-Ming Yung ◽  
Samuel D Paskin-Flerlage ◽  
Ivana Nikolic ◽  
Scott Pearsall ◽  
Ravindra Kumar ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Rna Seq ◽  
Differentiation Factor ◽  
Group I ◽  
Tgf Β1

Introduction: Excessive Transforming Growth Factor-β (TGF-β) signaling has been implicated in pulmonary arterial hypertension (PAH), based on activation of TGF-β effectors and transcriptional targets in affected lungs and the ability of TGF-β type I receptor (ALK5) inhibitors to improve experimental PAH. However, clinical use of ALK5 inhibitors has been limited by cardiovascular toxicity. Hypothesis: We tested whether or not selective blockade of TGF-β and Growth Differentiation Factor (GDF) ligands using a recombinant TGFβ type II receptor extracellular domain Fc fusion protein (TGFBRII-Fc) could impact experimental PAH. Methods: Male SD rats were injected with monocrotaline (MCT) and received vehicle or TGFBRII-Fc (15 mg/kg, twice per week, i.p.). C57BL/6 mice were treated with SU-5416 and hypoxia (SUGEN-HX) and received vehicle or TGFBRII-Fc. RNA-Seq was used to profile transcriptional changes in lungs of MCT rats. Circulating levels of GDF-15 were measured in 241 PAH patients and 41 healthy controls. Human pulmonary artery smooth muscle cells were used to examine signaling in vitro . Results: TGFBRII-Fc is a selective ligand trap, inhibiting the ability of GDF-15, TGF-β1, TGF-β3, but not TGF-β2 to activate SMAD2/3 in vitro . In MCT rats, prophylactic treatment with TGFBRII-Fc normalized expression of TGF-β transcriptional target PAI-1, attenuated PAH and vascular remodeling. Delayed administration of TGFBRII-Fc in rats with established PAH at 2.5 weeks led to improved survival, decreased PAH and remodeling at 5 weeks. Similar findings were observed in SUGEN-HX mice. No valvular abnormalities were found with TGFBRII-Fc treatment. RNA-Seq revealed GDF-15 to be the most highly upregulated TGF-β ligand in the lungs of MCT rats, with only modest increases in TGF-β1 and no change in TGF-β2/3 observed, suggesting a dominant role of GDF-15 in the pathophysiology of this model. Plasma levels of GDF-15 were significantly increased in patients with diverse etiologies of WHO Group I PAH. Conclusions: These findings demonstrate that a selective TGF-β/GDF-15 trap attenuates experimental PAH, remodeling and mortality, without causing valvulopathy. These data highlight the potential role of GDF-15 as a pathogenic molecule and therapeutic target in PAH.

Sign in / Sign up

Export Citation Format

Share Document