scholarly journals Activin A upregulates PTGS2 expression and increases PGE2 production in human granulosa-lutein cells

Reproduction ◽  
2016 ◽  
Vol 152 (6) ◽  
pp. 655-664 ◽  
Author(s):  
Pang-Pin Liu ◽  
Hsun-Ming Chang ◽  
Jung-Chien Cheng ◽  
Peter C K Leung

Activin A is one of the members of transforming growth factor-β superfamily that is expressed in human large luteal cells, and may act in an autocrine/paracrine manner to regulate luteal function. Prostaglandin-endoperoxide synthase 2 (PTGS2) enzyme and its derivative, prostaglandin E2 (PGE2), play significant roles in the regulation of corpus luteum formation and maintenance. To date, whether activin A can induce the expression of PTGS2 and the production of PGE2 in human granulosa-lutein cells is largely unknown. The aim of this study was to examine the effects of activin A on the regulation of PTGS2 expression and PGE2 production in human granulosa-lutein cells, and to investigate the underlying signal transduction mechanisms. In this study, the immortalized (SVOG cells) and primary human granulosa-lutein cells were used as the cell models. A TGF-β/activin type I receptor inhibitor, SB431542 and small interfering RNAs were used to investigate the activin A-induced downstream signaling pathway. We have demonstrated that activin A upregulated the expression of PTGS2 and increased the production of PGE2 via an ACVR1B-mediated SMAD2/3–SMAD4 signaling pathway. Our results suggest that activin A may be involved in the modulation of human corpus luteum formation via the induction of PTGS2 expression and PGE2 production.

Blood ◽  
2011 ◽  
Vol 118 (1) ◽  
pp. 88-97 ◽  
Author(s):  
Liying Zhang ◽  
Alessandro Magli ◽  
Jacquelyn Catanese ◽  
Zhaohui Xu ◽  
Michael Kyba ◽  
...  

Abstract Endoglin (Eng), an accessory receptor for the transforming growth factor β (TGF-β) superfamily, is required for proper hemangioblast and primitive hematopoietic development. However the mechanism by which endoglin functions at this early developmental stage is currently unknown. Transcriptional analyses of differentiating eng−/− and eng+/+ ES cells revealed that lack of endoglin leads to profound reductions in the levels of key hematopoietic regulators, including Scl, Lmo2, and Gata2. We also detected lower levels of phosphorylated Smad1 (pSmad1), a downstream target signaling molecule associated with the TGF-β pathway. Using doxycycline-inducible ES cell lines, we interrogated the TGF-β signaling pathway by expressing activated forms of ALK-1 and ALK-5, type I receptors for TGF-β. Our results indicate that ALK-1 signaling promotes hemangioblast development and hematopoiesis, as evidenced by colony assays, gene expression and FACS analyses, whereas signaling by ALK-5 leads to the opposite effect, inhibition of hemangioblast and hematopoietic development. In Eng−/− ES cells, ALK-1 rescued both the defective hemangioblast development, and primitive erythropoiesis, indicating that ALK-1 signaling can compensate for the absence of endoglin. We propose that endoglin regulates primitive hematopoiesis by modulating the activity of the Smad1/5 signaling pathway in early stages of development.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2070
Author(s):  
Pasquale Esposito ◽  
Daniela Verzola ◽  
Daniela Picciotto ◽  
Leda Cipriani ◽  
Francesca Viazzi ◽  
...  

A current hypothesis is that transforming growth factor-β signaling ligands, such as activin-A and myostatin, play a role in vascular damage in atherosclerosis and chronic kidney disease (CKD). Myostatin and activin-A bind with different affinity the activin receptors (type I or II), activating distinct intracellular signaling pathways and finally leading to modulation of gene expression. Myostatin and activin-A are expressed by different cell types and tissues, including muscle, kidney, reproductive system, immune cells, heart, and vessels, where they exert pleiotropic effects. In arterial vessels, experimental evidence indicates that myostatin may mostly promote vascular inflammation and premature aging, while activin-A is involved in the pathogenesis of vascular calcification and CKD-related mineral bone disorders. In this review, we discuss novel insights into the biology and physiology of the role played by myostatin and activin in the vascular wall, focusing on the experimental and clinical data, which suggest the involvement of these molecules in vascular remodeling and calcification processes. Moreover, we describe the strategies that have been used to modulate the activin downward signal. Understanding the role of myostatin/activin signaling in vascular disease and bone metabolism may provide novel therapeutic opportunities to improve the treatment of conditions still associated with high morbidity and mortality.


Blood ◽  
2008 ◽  
Vol 112 (8) ◽  
pp. 3154-3163 ◽  
Author(s):  
Sandrine Jeanpierre ◽  
Franck Emmanuel Nicolini ◽  
Bastien Kaniewski ◽  
Charles Dumontet ◽  
Ruth Rimokh ◽  
...  

Abstract Activin A, BMP2, and BMP4, 3 members of the transforming growth factor-β family, are involved in the regulation of hematopoiesis. Here, we explored the role of these molecules in human megakaryopoiesis using an in vitro serum-free assay. Our results highlight for the first time that, in the absence of thrombopoietin, BMP4 is able to induce CD34+ progenitor differentiation into megakaryocytes through all stages. Although we have previously shown that activin A and BMP2 are involved in erythropoietic commitment, these molecules have no effect on human megakaryopoietic engagement and differentiation. Using signaling pathway-specific inhibitors, we show that BMP4, like thrombopoietin, exerts its effects on human megakaryopoiesis through the JAK/STAT and mTor pathways. Inhibition of the BMP signaling pathway with blocking antibodies, natural soluble inhibitors (FLRG or follistatin), or soluble BMP receptors reveals that thrombopoietin uses the BMP4 pathway to induce megakaryopoiesis, whereas the inverse is not occurring. Finally, we show that thrombopoietin up-regulates the BMP4 autocrine loop in megakaryocytic progenitors by inducing their production of BMP4 and up-regulating BMP receptor expression. In summary, this work indicates that BMP4 plays an important role in the control of human megakaryopoiesis.


2007 ◽  
Vol 51 (8) ◽  
pp. 2905-2910 ◽  
Author(s):  
Mariana C. Waghabi ◽  
Michelle Keramidas ◽  
Claudia M. Calvet ◽  
Marcos Meuser ◽  
Maria de Nazaré C. Soeiro ◽  
...  

ABSTRACT The antiinflammatory cytokine transforming growth factor β (TGF-β) plays an important role in Chagas disease, a parasitic infection caused by the protozoan Trypanosoma cruzi. In the present study, we show that SB-431542, an inhibitor of the TGF-β type I receptor (ALK5), inhibits T. cruzi-induced activation of the TGF-β pathway in epithelial cells and in cardiomyocytes. Further, we demonstrate that addition of SB-431542 greatly reduces cardiomyocyte invasion by T. cruzi. Finally, SB-431542 treatment significantly reduces the number of parasites per infected cell and trypomastigote differentiation and release. Taken together, these data further confirm the major role of the TGF-β signaling pathway in both T. cruzi infection and T. cruzi cell cycle completion. Our present data demonstrate that small inhibitors of the TGF-β signaling pathway might be potential pharmacological tools for the treatment of Chagas disease.


Blood ◽  
2008 ◽  
Vol 111 (5) ◽  
pp. 2733-2743 ◽  
Author(s):  
Neil C. Robson ◽  
David J. Phillips ◽  
Tristan McAlpine ◽  
Amanda Shin ◽  
Suzanne Svobodova ◽  
...  

Activin-A is a transforming growth factor-β (TGF-β) superfamily member that plays a pivotal role in many developmental and reproductive processes. It is also involved in neuroprotection, apoptosis of tumor and some immune cells, wound healing, and cancer. Its role as an immune-regulating protein has not previously been described. Here we demonstrate for the first time that activin-A has potent autocrine effects on the capacity of human dendritic cells (DCs) to stimulate immune responses. Human monocyte-derived DCs (MoDCs) and the CD1c+ and CD123+ peripheral blood DC populations express both activin-A and the type I and II activin receptors. Furthermore, MoDCs and CD1c+ myeloid DCs rapidly secrete high levels of activin-A after exposure to bacteria, specific toll-like receptor (TLR) ligands, or CD40 ligand (CD40L). Blocking autocrine activin-A signaling in DCs using its antagonist, follistatin, enhanced DC cytokine (IL-6, IL-10, IL-12p70, and tumor necrosis factor-α [TNF-α]) and chemokine (IL-8, IP-10, RANTES, and MCP-1) production during CD40L stimulation, but not TLR-4 ligation. Moreover, antagonizing DC-derived activin-A resulted in significantly enhanced expansion of viral antigen-specific effector CD8+ T cells. These findings establish an immune-regulatory role for activin-A in DCs, highlighting the potential of antagonizing activin-A signaling in vivo to enhance vaccine immunogenicity.


2019 ◽  
Vol 12 (596) ◽  
pp. eaat7527 ◽  
Author(s):  
Jai Rautela ◽  
Laura F. Dagley ◽  
Carolina C. de Oliveira ◽  
Iona S. Schuster ◽  
Soroor Hediyeh-Zadeh ◽  
...  

Natural killer (NK) cells are innate lymphocytes that play a major role in immunosurveillance against tumor initiation and metastatic spread. The signals and checkpoints that regulate NK cell fitness and function in the tumor microenvironment are not well defined. Transforming growth factor–β (TGF-β) is a suppressor of NK cells that inhibits interleukin-15 (IL-15)–dependent signaling events and increases the abundance of receptors that promote tissue residency. Here, we showed that NK cells express the type I activin receptor ALK4, which, upon binding to its ligand activin-A, phosphorylated SMAD2/3 to suppress IL-15–mediated NK cell metabolism. Activin-A impaired human and mouse NK cell proliferation and reduced the production of granzyme B to impair tumor killing. Similar to TGF-β, activin-A also induced SMAD2/3 phosphorylation and stimulated NK cells to increase their cell surface expression of several markers of ILC1 cells. Activin-A also induced these changes in TGF-β receptor–deficient NK cells, suggesting that activin-A and TGF-β stimulate independent pathways that drive SMAD2/3-mediated NK cell suppression. Last, inhibition of activin-A by follistatin substantially slowed orthotopic melanoma growth in mice. These data highlight the relevance of examining TGF-β–independent SMAD2/3 signaling mechanisms as a therapeutic axis to relieve NK cell suppression and promote antitumor immunity.


2003 ◽  
Vol 23 (20) ◽  
pp. 7230-7242 ◽  
Author(s):  
A. Rebbapragada ◽  
H. Benchabane ◽  
J. L. Wrana ◽  
A. J. Celeste ◽  
L. Attisano

ABSTRACT Myostatin, a transforming growth factor β (TGF-β) family member, is a potent negative regulator of skeletal muscle growth. In this study we characterized the myostatin signal transduction pathway and examined its effect on bone morphogenetic protein (BMP)-induced adipogenesis. While both BMP7 and BMP2 activated transcription from the BMP-responsive I-BRE-Lux reporter and induced adipogenic differentiation, myostatin inhibited BMP7- but not BMP2-mediated responses. To dissect the molecular mechanism of this antagonism, we characterized the myostatin signal transduction pathway. We showed that myostatin binds the type II Ser/Thr kinase receptor. ActRIIB, and then partners with a type I receptor, either activin receptor-like kinase 4 (ALK4 or ActRIB) or ALK5 (TβRI), to induce phosphorylation of Smad2/Smad3 and activate a TGF-β-like signaling pathway. We demonstrated that myostatin prevents BMP7 but not BMP2 binding to its receptors and that BMP7-induced heteromeric receptor complex formation is blocked by competition for the common type II receptor, ActRIIB. Thus, our results reveal a strikingly specific antagonism of BMP7-mediated processes by myostatin and suggest that myostatin is an important regulator of adipogenesis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Bo Zhang ◽  
Lihua Gao ◽  
Chunsheng Shao ◽  
Mingsi Deng ◽  
Liangjian Chen

Chewing areca nut (betel quid) is strongly associated with oral submucous fibrosis (OSF), a pre-cancerous lesion. Among the areca alkaloids, arecoline is the main agent responsible for fibroblast proliferation; however, the specific molecular mechanism of arecoline affecting the OSF remains unclear. The present study revealed that arecoline treatment significantly enhanced Transforming growth factor-β (TGF-β)-induced buccal mucosal fibroblast (BMF) activation and fibrotic changes. Arecoline interacts with phosphodiesterase 4A (PDE4A) to exert its effects through modulating PDE4A activity but not PDE4A expression. PDE4A silence reversed the effects of arecoline on TGF-β-induced BMFs activation and fibrotic changes. Moreover, the exchange protein directly activated by cAMP 1 (Epac1)-selective Cyclic adenosine 3′,5′-monophosphate (cAMP) analog (8-Me-cAMP) but not the protein kinase A (PKA)-selective cAMP analog (N6-cAMP) remarkably suppressed α-smooth muscle actin(α-SMA) and Collagen Type I Alpha 1 Chain (Col1A1) protein levels in response to TGF-β1 and arecoline co-treatment, indicating that cAMP-Epac1 but not cAMP-PKA signaling is involved in arecoline functions on TGF-β1-induced BMFs activation. In conclusion, arecoline promotes TGF-β1-induced BMFs activation through enhancing PDE4A activity and the cAMP-Epac1 signaling pathway during OSF. This novel mechanism might provide more powerful strategies for OSF treatment, requiring further in vivo and clinical investigation.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Chuang Gao ◽  
Xin Cao ◽  
Lili Huang ◽  
Yueqi Bao ◽  
Tao Li ◽  
...  

Background. Transforming growth factor-β (TGF-β) plays a major role in CNV. However, the mechanism is unclear. This study investigates the effect of Pirfenidone (PFD) on TGF-β/Smad signaling pathway on the development of choroidal neovascular fibrosis in choroidal neovascularization (CNV) mouse model. C57BL/6J male mice (aged from 6 to 8 weeks) received intravitreal injections of phosphate-buffered saline (PBS)/PFD solution on 14 days after laser injury. Mice were anesthetized by intraperitoneal injection of 4% pentobarbital (0.05 mg/g body weight). Optical Coherence Tomography (OCT), Fundus Fluorescein angiography (FFA), and hematoxylin-eosin (HE) were used to assess CNV formation. The fibrosis area was monitored by staining the collagen type I (Col-I). Western blotting was used to analyze the expression of TGF-β2, Smad 2/3, phosphorylated Smad 2/3 (p-Smad 2/3), and α-smooth muscle actin (α-SMA). Terminal deoxynucleotidy1 transferase dUTP nick-end labelling (TUNEL) assay was performed on cryosections of mouse eyes to detect apoptosis. Our data showed PFD inhibited areas of fibrosis during day 21 to day 28. We also found that the levels of TGF-β2 protein expressions increasingly reached the peak till the 3rd week during the CNV development. The protein levels of Smad 2/3, p-Smad 2/3, and α-SMA also increased significantly in CNV mice, but this response was profoundly suppressed by the TGF-β inhibitor PFD. The results of this study suggest that TGF-β2 represents a target to prevent or treat choroidal neovascular fibrosis, and PFD may provide an alternative to traditional methods for Wet Age-related macular degeneration (wAMD) treatment.


2021 ◽  
Vol 22 (24) ◽  
pp. 13491
Author(s):  
Hideki Sugii ◽  
Mhd Safwan Albougha ◽  
Orie Adachi ◽  
Hiroka Tomita ◽  
Atsushi Tomokiyo ◽  
...  

Activin A, a member of transforming growth factor-β superfamily, is involved in the regulation of cellular differentiation and promotes tissue healing. Previously, we reported that expression of activin A was upregulated around the damaged periodontal tissue including periodontal ligament (PDL) tissue and alveolar bone, and activin A promoted PDL-related gene expression of human PDL cells (HPDLCs). However, little is known about the biological function of activin A in alveolar bone. Thus, this study analyzed activin A-induced biological functions in preosteoblasts (Saos2 cells). Activin A promoted osteoblastic differentiation of Saos2 cells. Activin receptor-like kinase (ALK) 1, an activin type I receptor, was more strongly expressed in Saos2 cells than in HPDLCs, and knockdown of ALK1 inhibited activin A-induced osteoblastic differentiation of Saos2 cells. Expression of ALK1 was upregulated in alveolar bone around damaged periodontal tissue when compared with a nondamaged site. Furthermore, activin A promoted phosphorylation of Smad1/5/9 during osteoblastic differentiation of Saos2 cells and knockdown of ALK1 inhibited activin A-induced phosphorylation of Smad1/5/9 in Saos2 cells. Collectively, these findings suggest that activin A promotes osteoblastic differentiation of preosteoblasts through the ALK1-Smad1/5/9 pathway and could be used as a therapeutic product for the healing of alveolar bone as well as PDL tissue.


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