Endogenous patterns of TGFbeta superfamily signaling during early Xenopus development

Development ◽  
2000 ◽  
Vol 127 (13) ◽  
pp. 2917-2931 ◽  
Author(s):  
S. Faure ◽  
M.A. Lee ◽  
T. Keller ◽  
P. ten Dijke ◽  
M. Whitman
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Ectopic Expression ◽  
Xenopus Embryo ◽  
Bmp Signaling ◽  
Type I ◽  
Embryonic Cells ◽  
Xenopus Development ◽  
Zygotic Transcription ◽  
Carboxy Terminal

Transforming growth factor beta (TGFbeta) superfamily signaling has been implicated in patterning of the early Xenopus embryo. Upon ligand stimulation, TGFbeta receptors phosphorylate Smad proteins at carboxy-terminal SS(V/M)S consensus motifs. Smads 1/5/8, activated by bone morphogenetic protein (BMP) signaling, induce ventral mesoderm whereas Smad2, activated by activin-like ligands, induces dorsal mesoderm. Although ectopic expression studies are consistent with roles for TGFbeta signals in early Xenopus embryogenesis, when and where BMP and activin-like signaling pathways are active endogenously has not been directly examined. In this study, we investigate the temporal and spatial activation of TGFbeta superfamily signaling in early Xenopus development by using antibodies specific for the type I receptor-phosphorylated forms of Smad1/5/8 and Smad2. We find that Smad1/5/8 and two distinct isoforms of Smad2, full-length Smad2 and Smad2(delta)exon3, are phosphorylated in early embryos. Both Smad1/5/8 and Smad2/Smad2(delta)exon3 are activated after, but not before, the mid-blastula transition (MBT). Endogenous activation of Smad2/Smad2(delta)exon3 requires zygotic transcription, while Smad1/5/8 activation at MBT appears to involve transcription-independent regulation. We also find that the competence of embryonic cells to respond to TGF(delta) superfamily ligands is temporally regulated and may be a determinant of early patterning. Levels of phospho-Smad1/5/8 and of phospho-Smad2/Smad2(delta)exon3 are asymmetrically distributed across both the animal-vegetal and dorsoventral axes. The timing of the development of these asymmetries differs for phospho-Smad1/5/8 and for phospho-Smad2/Smad2(delta)exon3, and the spatial distribution of phosphorylation of each Smad changes dramatically as gastrulation begins. We discuss the implications of our results for endogenous functions of BMP and activin-like signals as candidate morphogens regulating primary germ layer formation and dorsoventral patterning of the early Xenopus embryo.

In vivo analysis using variants of zebrafish BMPR-IA: range of action and involvement of BMP in ectoderm patterning

Development ◽  
1999 ◽  
Vol 126 (1) ◽  
pp. 181-190 ◽  
Author(s):  
M. Nikaido ◽  
M. Tada ◽  
H. Takeda ◽  
A. Kuroiwa ◽  
N. Ueno
Keyword(s):  
Cell Fate ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Active Form ◽  
Ectopic Expression ◽  
Signal Propagation ◽  
Early Embryo ◽  
Type I ◽  
Cell Fate Conversion

It has been an intriguing problem whether the polypeptide growth factors belonging to the transforming growth factor-beta (TGF-beta) superfamily function as direct and long-range signaling molecules in pattern formation of the early embryo. In this study, we examined the mechanism of signal propagation of bone morphogenetic protein (BMP) in the ectodermal patterning of zebrafish embryos, in which BMP functions as an epidermal inducer and a neural inhibitor. To estimate the effective range of zbmp-2, we first performed whole-mount in situ hybridization analysis. The zbmp-2-expressing domain and the neuroectoderm, marked by otx-2 expression, were complementary, suggesting that BMP has a short-range effect in vivo. Moreover, mosaic experiments using a constitutively active form of a zebrafish BMP type I receptor (CA-BRIA) demonstrated that the cell-fate conversion, revealed by ectopic expression of gata-3 and repression of otx-2, occurred in a cell-autonomous manner, denying the involvement of the relay mechanism. We also found that zbmp-2 was induced cell autonomously within the transplanted cells in the host ectoderm, suggesting that BMP cannot influence even the neighboring cells. This result is consistent with the observation that there is no gap between the expression domains of zbmp-2 and otx-2. Taken together, we propose that, in ectodermal patterning, BMP exerts a direct and cell-autonomous effect to fate uncommitted ectodermal cells to become epidermis.

scholarly journals The N domain of Smad7 is essential for specific inhibition of transforming growth factor-β signaling

2001 ◽  
Vol 155 (6) ◽  
pp. 1017-1028 ◽  
Author(s):  
Aki Hanyu ◽  
Yasuhiro Ishidou ◽  
Takanori Ebisawa ◽  
Tomomasa Shimanuki ◽  
Takeshi Imamura ◽  
...  
Keyword(s):  
Growth Factor ◽  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Amino Acid Sequences ◽  
Bmp Signaling ◽  
Type I ◽  
Specific Inhibition ◽  
Amino Terminal ◽  
Carboxy Terminal

Inhibitory Smads (I-Smads) repress signaling by cytokines of the transforming growth factor-β (TGF-β) superfamily. I-Smads have conserved carboxy-terminal Mad homology 2 (MH2) domains, whereas the amino acid sequences of their amino-terminal regions (N domains) are highly divergent from those of other Smads. Of the two different I-Smads in mammals, Smad7 inhibited signaling by both TGF-β and bone morphogenetic proteins (BMPs), whereas Smad6 was less effective in inhibiting TGF-β signaling. Analyses using deletion mutants and chimeras of Smad6 and Smad7 revealed that the MH2 domains were responsible for the inhibition of both TGF-β and BMP signaling by I-Smads, but the isolated MH2 domains of Smad6 and Smad7 were less potent than the full-length Smad7 in inhibiting TGF-β signaling. The N domains of I-Smads determined the subcellular localization of these molecules. Chimeras containing the N domain of Smad7 interacted with the TGF-β type I receptor (TβR-I) more efficiently, and were more potent in repressing TGF-β signaling, than those containing the N domain of Smad6. The isolated N domain of Smad7 physically interacted with the MH2 domain of Smad7, and enhanced the inhibitory activity of the latter through facilitating interaction with TGF-β receptors. The N domain of Smad7 thus plays an important role in the specific inhibition of TGF-β signaling.

scholarly journals LRIG proteins regulate lipid metabolism via BMP signaling and affect the risk of type 2 diabetes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Carl Herdenberg ◽  
Pascal M. Mutie ◽  
Ola Billing ◽  
Ahmad Abdullah ◽  
Rona J. Strawbridge ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Lipid Metabolism ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Ectopic Expression ◽  
Bmp Signaling ◽  
Null Mouse ◽  
Growth Factor Signaling

AbstractLeucine-rich repeats and immunoglobulin-like domains (LRIG) proteins have been implicated as regulators of growth factor signaling; however, the possible redundancy among mammalian LRIG1, LRIG2, and LRIG3 has hindered detailed elucidation of their physiological functions. Here, we show that Lrig-null mouse embryonic fibroblasts (MEFs) are deficient in adipogenesis and bone morphogenetic protein (BMP) signaling. In contrast, transforming growth factor-beta (TGF-β) and receptor tyrosine kinase (RTK) signaling appeared unaltered in Lrig-null cells. The BMP signaling defect was rescued by ectopic expression of LRIG1 or LRIG3 but not by expression of LRIG2. Caenorhabditis elegans with mutant LRIG/sma-10 variants also exhibited a lipid storage defect. Human LRIG1 variants were strongly associated with increased body mass index (BMI) yet protected against type 2 diabetes; these effects were likely mediated by altered adipocyte morphology. These results demonstrate that LRIG proteins function as evolutionarily conserved regulators of lipid metabolism and BMP signaling and have implications for human disease.

scholarly journals Non-Canonical Regulation of Type I Collagen through Promoter Binding of SOX2 and Its Contribution to Ameliorating Pulmonary Fibrosis by Butylidenephthalide

2018 ◽  
Vol 19 (10) ◽  
pp. 3024 ◽  
Author(s):  
Hong-Meng Chuang ◽  
Li-Ing Ho ◽  
Mao-Hsuan Huang ◽  
Kun-Lun Huang ◽  
Tzyy-Wen Chiou ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Binding Site ◽  
Transforming Growth Factor Beta ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Pulmonary Ventilation ◽  
Ectopic Expression ◽  
Alveolar Epithelial Cells ◽  
Type I ◽  
Mice Model

Pulmonary fibrosis is a fatal respiratory disease that gradually leads to dyspnea, mainly accompanied by excessive collagen production in the fibroblast and myofibroblast through mechanisms such as abnormal alveolar epithelial cells remodeling and stimulation of the extracellular matrix (ECM). Our results show that a small molecule, butylidenephthalide (BP), reduces type I collagen (COL1) expression in Transforming Growth Factor beta (TGF-β)-induced lung fibroblast without altering downstream pathways of TGF-β, such as Smad phosphorylation. Treatment of BP also reduces the expression of transcription factor Sex Determining Region Y-box 2 (SOX2), and the ectopic expression of SOX2 overcomes the inhibitory actions of BP on COL1 expression. We also found that serial deletion of the SOX2 binding site on 3′COL1 promoter results in a marked reduction in luciferase activity. Moreover, chromatin immunoprecipitation, which was found on the SOX2 binding site of the COL1 promoter, decreases in BP-treated cells. In an in vivo study using a bleomycin-induced pulmonary fibrosis C57BL/6 mice model, mice treated with BP displayed reduced lung fibrosis and collagen deposition, recovering in their pulmonary ventilation function. The reduction of SOX2 expression in BP-treated lung tissues is consistent with our findings in the fibroblast. This is the first report that reveals a non-canonical regulation of COL1 promoter via SOX2 binding, and contributes to the amelioration of pulmonary fibrosis by BP treatment.

scholarly journals Crosstalk between MicroRNA and Oxidative Stress in Primary Open-Angle Glaucoma

2021 ◽  
Vol 22 (5) ◽  
pp. 2421
Author(s):  
Saray Tabak ◽  
Sofia Schreiber-Avissar ◽  
Elie Beit-Yannai
Keyword(s):  
Oxidative Stress ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Additional Treatment ◽  
Type I ◽  
Open Angle ◽  
Outflow Resistance ◽  
Stress Injury

Reactive oxygen species (ROS) plays a key role in the pathogenesis of primary open-angle glaucoma (POAG), a chronic neurodegenerative disease that damages the trabecular meshwork (TM) cells, inducing apoptosis of the retinal ganglion cells (RGC), deteriorating the optic nerve head, and leading to blindness. Aqueous humor (AH) outflow resistance and intraocular pressure (IOP) elevation contribute to disease progression. Nevertheless, despite the existence of pharmacological and surgical treatments, there is room for the development of additional treatment approaches. The following review is aimed at investigating the role of different microRNAs (miRNAs) in the expression of genes and proteins involved in the regulation of inflammatory and degenerative processes, focusing on the delicate balance of synthesis and deposition of extracellular matrix (ECM) regulated by chronic oxidative stress in POAG related tissues. The neutralizing activity of a couple of miRNAs was described, suggesting effective downregulation of pro-inflammatory and pro-fibrotic signaling pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), transforming growth factor-beta 2 (TGF-β2), Wnt/β-Catenin, and PI3K/AKT. In addition, with regards to the elevated IOP in many POAG patients due to increased outflow resistance, Collagen type I degradation was stimulated by some miRNAs and prevented ECM deposition in TM cells. Mitochondrial dysfunction as a consequence of oxidative stress was suppressed following exposure to different miRNAs. In contrast, increased oxidative damage by inhibiting the mTOR signaling pathway was described as part of the action of selected miRNAs. Summarizing, specific miRNAs may be promising therapeutic targets for lowering or preventing oxidative stress injury in POAG patients.

scholarly journals Targeting lncRNA H19/miR-29b/COL1A1 Axis Impedes Myofibroblast Activities of Precancerous Oral Submucous Fibrosis

2021 ◽  
Vol 22 (4) ◽  
pp. 2216
Author(s):  
Cheng-Chia Yu ◽  
Yi-Wen Liao ◽  
Pei-Ling Hsieh ◽  
Yu-Chao Chang
Keyword(s):  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Oral Submucous Fibrosis ◽  
Ectopic Expression ◽  
Collagen Gel ◽  
Type I ◽  
Migration Ability ◽  
Potentially Malignant ◽  
Submucous Fibrosis

Oral submucous fibrosis (OSF) is known as a potentially malignant disorder, which may result from chemical irritation due to areca nuts (such as arecoline). Emerging evidence suggests that fibrogenesis and carcinogenesis are regulated by the interaction of long noncoding RNAs (lncRNAs) and microRNAs. Among these regulators, profibrotic lncRNA H19 has been found to be overexpressed in several fibrosis diseases. Here, we examined the expression of H19 in OSF specimens and its functional role in fibrotic buccal mucosal fibroblasts (fBMFs). Our results indicate that the aberrantly overexpressed H19 contributed to higher myofibroblast activities, such as collagen gel contractility and migration ability. We also demonstrated that H19 interacted with miR-29b, which suppressed the direct binding of miR-29b to the 3′-untranslated region of type I collagen (COL1A1). We showed that ectopic expression of miR-29b ameliorated various myofibroblast phenotypes and the expression of α-smooth muscle actin (α-SMA), COL1A1, and fibronectin (FN1) in fBMFs. In OSF tissues, we found that the expression of miR-29b was downregulated and there was a negative correlation between miR-29b and these fibrosis markers. Lastly, we demonstrate that arecoline stimulated the upregulation of H19 through the transforming growth factor (TGF)-β pathway. Altogether, this study suggests that increased TGF-β secretion following areca nut chewing may induce the upregulation of H19, which serves as a natural sponge for miR-29b and impedes its antifibrotic effects.

scholarly journals Utilizing the ABC Transporter for Growth Factor Production by fleQ Deletion Mutant of Pseudomonas fluorescens

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 679
Author(s):  
Benedict-Uy Fabia ◽  
Joshua Bingwa ◽  
Jiyeon Park ◽  
Nguyen-Mihn Hieu ◽  
Jung-Hoon Ahn
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Pseudomonas Fluorescens ◽  
Abc Transporter ◽  
Transforming Growth Factor Beta ◽  
Deletion Mutant ◽  
Transforming Growth Factor ◽  
Gene Knockout ◽  
Type I ◽  
Double Deletion

Pseudomonas fluorescens, a gram-negative bacterium, has been proven to be a capable protein manufacturing factory (PMF). Utilizing its ATP-binding cassette (ABC) transporter, a type I secretion system, P. fluorescens has successfully produced recombinant proteins. However, besides the target proteins, P. fluorescens also secretes unnecessary background proteins that complicate protein purification and other downstream processes. One of the background proteins produced in large amounts is FliC, a flagellin protein. In this study, the master regulator of flagella gene expression, fleQ, was deleted from P. fluorescens Δtp, a lipase and protease double-deletion mutant, via targeted gene knockout. FleQ directs flagella synthesis, so the new strain, P. fluorescens ΔfleQ, does not produce flagella-related proteins. This not only simplifies purification but also makes P. fluorescens ΔfleQ an eco-friendly expression host because it will not survive outside a controlled environment. Six recombinant growth factors, namely, insulin-like growth factors I and II, beta-nerve growth factor, fibroblast growth factor 1, transforming growth factor beta, and tumor necrosis factor beta, prepared using our supercharging method, were successfully secreted by P. fluorescens ΔfleQ. Our findings demonstrate the potential of P. fluorescens ΔfleQ, combined with our supercharging process, as a PMF.

scholarly journals Formation of hetero-oligomeric complexes of type I and type II receptors for transforming growth factor-beta.

1994 ◽  
Vol 269 (31) ◽  
pp. 20172-20178 ◽  
Author(s):  
H. Yamashita ◽  
P. ten Dijke ◽  
P. Franzén ◽  
K. Miyazono ◽  
C.H. Heldin
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Type I ◽  
Type Ii ◽  
Growth Factor Beta

Collagen matrices attenuate the collagen-synthetic response of cultured fibroblasts to TGF-beta

1995 ◽  
Vol 108 (3) ◽  
pp. 1251-1261 ◽  
Author(s):  
R.A. Clark ◽  
L.D. Nielsen ◽  
M.P. Welch ◽  
J.M. McPherson
Keyword(s):  
Growth Factor ◽  
Granulation Tissue ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Collagen Matrix ◽  
Dermal Fibroblasts ◽  
Type I ◽  
Collagen Gels ◽  
Type I Procollagen ◽  
Growth Factor Beta

Transforming growth factor-beta, a potent modulator of cell function, induces fibroblasts cultured on plastic to increase collagen synthesis. In 5- and 7-day porcine skin wounds, which have minimal to moderate collagen matrix, respectively, transforming growth factor-beta and type I procollagen were coordinately expressed throughout the granulation tissue. However, in 10-day collagen-rich granulation tissue type I procollagen expression diminished despite persistence of transforming growth factor-beta. To investigate whether collagen matrix attenuates the collagen-synthetic response of fibroblasts to transforming growth factor-beta, we cultured human dermal fibroblasts in conditions that simulate collagen-rich granulation tissue. Therefore, human dermal fibroblasts were suspended in attached collagen gels and collagen and noncollagen production was assayed in the absence and presence of transforming growth factor-beta. Although transforming growth factor-beta stimulated collagen synthesis by fibroblasts cultured in the collagen gels, these fibroblasts consistently produced less collagen than similarly treated fibroblasts cultured on plastic. This phenomenon was not secondary to nonspecific binding of transforming growth factor-beta to the collagen matrix. Fibroblasts cultured in a fibrin gel responded to transforming growth factor-beta similarly to fibroblasts cultured on plastic. Using immunofluorescence probes to type I procollagen, we observed that transforming growth factor-beta increased type I procollagen expression in most fibroblasts cultured on plastic, but only in occasional fibroblasts cultured in collagen gels. From these data we conclude that collagen matrices attenuate the collagen synthetic response of fibroblast to transforming growth factor-beta in vitro and possibly in vivo.

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