scholarly journals Induction of Ectopic Olfactory Structures and Bone Morphogenetic Protein Inhibition by Rossy, a Group XII Secreted Phospholipase A2

2005 ◽  
Vol 25 (9) ◽  
pp. 3608-3619 ◽  
Author(s):  
Ignacio Muñoz-Sanjuán ◽  
Ali H. Brivanlou
Keyword(s):  
Bone Morphogenetic Protein ◽  
Transcriptional Activation ◽  
Transforming Growth Factor ◽  
Biological Activities ◽  
Transforming Growth Factor Β ◽  
Hydrolytic Activity ◽  
Binding Activity ◽  
Bmp Signaling ◽  
Bioactive Lipids ◽  
Morphogenetic Protein

ABSTRACT The secreted phospholipases A2 (sPLA2s) comprise a family of small secreted proteins with the ability to catalyze the generation of bioactive lipids through glycophospholipid hydrolysis. Recently, a large number of receptor proteins and extracellular binding partners for the sPLA2s have been identified, suggesting that these secreted factors might exert a subset of their broad spectrum of biological activities independently of their enzymatic activity. Here, we describe an activity for the sPLA2 group XII (sPLA2-gXII) gene during Xenopus laevis early development. In the ectoderm, sPLA2-gXII acts as a neural inducer by blocking bone morphogenetic protein (BMP) signaling. Gain of function in embryos leads to ectopic neurogenesis and to the specification of ectopic olfactory sensory structures, including olfactory bulb and sensory epithelia. This activity is conserved in the Drosophila melanogaster, Xenopus, and mammalian orthologs and appears to be independent of the lipid hydrolytic activity. Because of its effect on olfactory neurogenesis, we have renamed this gene Rossy, in homage to the Spanish actress Rossy de Palma. We present evidence that Rossy/sPLA2-gXII can inhibit the transcriptional activation of BMP direct-target gene reporters in Xenopus and mouse P19 embryonic carcinoma cells through the loss of DNA-binding activity of activated Smad1/4 complexes. Collectively, these data represent the first evidence for signaling cross talk between a secreted phospholipase A2 and the BMP/transforming growth factor β pathways and identify Rossy/sPLA2-gXII as the only factor thus far described which is sufficient to induce anterior sensory neural structures during vertebrate development.

scholarly journals GDF11 promotes osteogenesis as opposed to MSTN, and follistatin, a MSTN/GDF11 inhibitor, increases muscle mass but weakens bone

2020 ◽  
Vol 117 (9) ◽  
pp. 4910-4920 ◽  
Author(s):  
Joonho Suh ◽  
Na-Kyung Kim ◽  
Seung-Hoon Lee ◽  
Je-Hyun Eom ◽  
Youngkyun Lee ◽  
...  
Keyword(s):  
Bone Mass ◽  
Muscle Mass ◽  
Transforming Growth Factor ◽  
Bone Fractures ◽  
Muscle Growth ◽  
Transforming Growth Factor Β ◽  
Biochemical Properties ◽  
Bmp Signaling ◽  
Morphogenetic Protein ◽  
Perinatal Lethality

Growth and differentiation factor 11 (GDF11) and myostatin (MSTN) are closely related transforming growth factor β (TGF-β) family members, but their biological functions are quite distinct. While MSTN has been widely shown to inhibit muscle growth, GDF11 regulates skeletal patterning and organ development during embryogenesis. Postnatal functions of GDF11, however, remain less clear and controversial. Due to the perinatal lethality ofGdf11null mice, previous studies used recombinant GDF11 protein to prove its postnatal function. However, recombinant GDF11 and MSTN proteins share nearly identical biochemical properties, and most GDF11-binding molecules have also been shown to bind MSTN, generating the possibility that the effects mediated by recombinant GDF11 protein actually reproduce the endogenous functions of MSTN. To clarify the endogenous functions of GDF11, here, we focus on genetic studies and show thatGdf11null mice, despite significantly down-regulatingMstnexpression, exhibit reduced bone mass through impaired osteoblast (OB) and chondrocyte (CH) maturations and increased osteoclastogenesis, while the opposite is observed inMstnnull mice that display enhanced bone mass. Mechanistically,Mstndeletion up-regulatesGdf11expression, which activates bone morphogenetic protein (BMP) signaling pathway to enhance osteogenesis. Also, mice overexpressing follistatin (FST), a MSTN/GDF11 inhibitor, exhibit increased muscle mass accompanied by bone fractures, unlikeMstnnull mice that display increased muscle mass without fractures, indicating that inhibition of GDF11 impairs bone strength. Together, our findings suggest that GDF11 promotes osteogenesis in contrast to MSTN, and these opposing roles of GDF11 and MSTN must be considered to avoid the detrimental effect of GDF11 inhibition when developing MSTN/GDF11 inhibitors for therapeutic purposes.

Effects of bone morphogenetic protein 15 (BMP15) knockdown on porcine testis morphology and spermatogenesis

2020 ◽  
Vol 32 (11) ◽  
pp. 999
Author(s):  
Tao Tang ◽  
Qiyuan Lin ◽  
Yufeng Qin ◽  
Xinyu Liang ◽  
Yang Guo ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Transforming Growth Factor ◽  
Biological Function ◽  
Transforming Growth Factor Β ◽  
Reproductive Capacity ◽  
Ovary Development ◽  
Sperm Viability ◽  
Morphogenetic Protein ◽  
Bone Morphogenetic Protein 15

Bone morphogenetic protein 15 (BMP15) is a member of the transforming growth factor-β (TGFB) superfamily that plays an essential role in mammalian ovary development, oocyte maturation and litter size. However, little is known regarding the expression pattern and biological function of BMP15 in male gonads. In this study we established, for the first time, a transgenic pig model with BMP15 constitutively knocked down by short hairpin (sh) RNA. The transgenic boars were fertile, but sperm viability was decreased. Further analysis of the TGFB/SMAD pathway and markers of reproductive capacity, namely androgen receptor and protamine 2, failed to identify any differentially expressed genes. These results indicate that, in the pig, the biological function of BMP15 in the development of male gonads is not as crucial as in ovary development. However, the role of BMP15 in sperm viability requires further investigation. This study provides new insights into the role of BMP15 in male pig reproduction.

SMAD7 controls iron metabolism as a potent inhibitor of hepcidin expression

Blood ◽  
2010 ◽  
Vol 115 (13) ◽  
pp. 2657-2665 ◽  
Author(s):  
Katarzyna Mleczko-Sanecka ◽  
Guillem Casanovas ◽  
Anan Ragab ◽  
Katja Breitkopf ◽  
Alexandra Müller ◽  
...  
Keyword(s):  
Growth Factor ◽  
Iron Metabolism ◽  
Negative Feedback ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Bmp Signaling ◽  
Hepcidin Expression ◽  
Morphogenetic Protein ◽  
Smad Protein

Abstract Hepcidin is the master regulatory hormone of systemic iron metabolism. Hepcidin deficiency causes common iron overload syndromes whereas its overexpression is responsible for microcytic anemias. Hepcidin transcription is activated by the bone morphogenetic protein (BMP) and the inflammatory JAK-STAT pathways, whereas comparatively little is known about how hepcidin expression is inhibited. By using high-throughput siRNA screening we identified SMAD7 as a potent hepcidin suppressor. SMAD7 is an inhibitory SMAD protein that mediates a negative feedback loop to both transforming growth factor-β and BMP signaling and that recently was shown to be coregulated with hepcidin via SMAD4 in response to altered iron availability in vivo. We show that SMAD7 is coregulated with hepcidin by BMPs in primary murine hepatocytes and that SMAD7 overexpression completely abolishes hepcidin activation by BMPs and transforming growth factor-β. We identify a distinct SMAD regulatory motif (GTCAAGAC) within the hepcidin promoter involved in SMAD7-dependent hepcidin suppression, demonstrating that SMAD7 does not simply antagonize the previously reported hemojuvelin/BMP-responsive elements. This work identifies a potent inhibitory factor for hepcidin expression and uncovers a negative feedback pathway for hepcidin regulation, providing insight into a mechanism how hepcidin expression may be limited to avoid iron deficiency.

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