20-Hydroxyecdysone activates the protective arm of the RAAS via Mas receptor

Author(s):  
René Lafont ◽  
Maria Serova ◽  
Blaise Didry-Barca ◽  
Sophie Raynal ◽  
Louis Guibout ◽  
...  

20-Hydroxyecdysone (20E) is a steroid hormone that plays a key role in insect development through nuclear ecdysteroid receptors (EcR/RXR complex) and at least one membrane GPCR receptor (DopEcR). It also displays numerous pharmacological effects in mammals, where its mechanism of action is still debated, involving either an unidentified GPCR or the estrogen ERβ receptor. The goal of this study was to better understand 20E mechanism of action in mammals. A mouse myoblast cell line (C2C12) and the gene expression of myostatin (a negative regulator of muscle growth) was used as a reporter system of anabolic activity. Experiments using protein-bound 20E established the involvement of a membrane receptor. 20E-like effects were also observed with angiotensin-(1-7), the endogenous ligand of Mas. Additionally, the effect on myostatin gene expression was abolished by Mas receptor knock-down using small interfering RNA (siRNA) or pharmacological inhibitors. 17β-Estradiol (E2) also inhibited myostatin gene expression, but protein-bound E2 was inactive, and E2 activity was not abolished by angiotensin-(1-7) antagonists. A mechanism involving cooperation between the Mas receptor and a membrane-bound palmitoylated estrogen receptor is proposed. The possibility to activate the Mas receptor with a safe steroid molecule is consistent with the pleiotropic pharmacological effects of ecdysteroids in mammals and, indeed, the proposed mechanism may explain the close similarity between angiotensin-(1-7)’s and 20E’s effects. Our findings open up many possible therapeutic developments involving stimulation of the protective arm of the renin-angiotensin-aldosterone system (RAAS) with 20E.

2020 ◽  
Author(s):  
René Lafont ◽  
Sophie Raynal ◽  
Maria Serova ◽  
Blaise Didry-Barca ◽  
Louis Guibout ◽  
...  

ABSTRACT20-Hydroxyecdysone (20E) is a steroid hormone that plays a key role in insect development through nuclear ecdysone receptors (EcRs) and at least one membrane GPCR receptor (DopEcR) and displays numerous pharmacological effects in mammals. However, its mechanism of action is still debated, involving either an unidentified GPCR or the estrogen ERβ receptor. The goal of our study was to better understand 20E mechanism of action.A mouse myoblast cell line (C2C12) and the gene expression of myostatin (a negative regulator of muscle growth) was used as a reporter system of anabolic activity. Experiments using protein-bound 20E established the involvement of a membrane receptor. 20E-like effects were also observed with Angiotensin-(1-7), the endogenous ligand of Mas. Additionally, the effect on myostatin gene expression was abolished by Mas receptor knock-down using small interfering RNA (siRNA) or pharmacological inhibitors.17β-Estradiol (E2) also inhibited myostatin gene expression, but protein-bound E2 was inactive, and E2 activity was not abolished by angiotensin-(1-7) antagonists. A mechanism involving cooperation between Mas receptor and a membrane-bound palmitoylated estrogen receptor is proposed.The possibility to activate the Mas receptor with a safe steroid molecule is consistent with the pleiotropic pharmacological effects of ecdysteroids in mammals and indeed this mechanism may explain the close similarity between angiotensin-(1-7) and 20E effects. Our findings open a lot of possible therapeutic developments by stimulating the protective arm of the renin-angiotensin-aldosterone system (RAAS) with 20E.


2004 ◽  
Vol 287 (4) ◽  
pp. C1031-C1040 ◽  
Author(s):  
Mônica Senna Salerno ◽  
Mark Thomas ◽  
Davanea Forbes ◽  
Trevor Watson ◽  
Ravi Kambadur ◽  
...  

Myostatin is a negative regulator of muscle growth, and absence of the functional myostatin protein leads to the heavy muscle phenotype in both mouse and cattle. Although the role of myostatin in controlling muscle mass is established, little is known of the mechanisms regulating the expression of the myostatin gene. In this study, we have characterized the murine myostatin promoter in vivo. Various constructs of the murine myostatin promoter were injected into the quadriceps muscle of mice, and the reporter luciferase activity was analyzed. The results indicate that of the seven E-boxes present in the 2.5-kb fragment of the murine myostatin promoter, the E5 E-box plays an important role in the regulation of promoter activity in vivo. Furthermore, the in vitro studies demonstrated that MyoD preferentially binds and upregulates the murine myostatin promoter activity. We also analyzed the activity of the bovine and murine promoters in murine skeletal muscle and showed that, despite displaying comparable levels of activity in murine myoblast cultures, bovine myostatin promoter activity is much weaker than murine myostatin promoter in mice. Finally, we demonstrate that in vivo, the 2.5-kb region of the murine myostatin promoter is sufficient to drive the activity of the reporter gene in a fiber type-specific manner.


2009 ◽  
Vol 37 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Thomas S. Postler ◽  
Murat T. Budak ◽  
Tejvir S. Khurana ◽  
Neal A. Rubinstein

Extraocular muscles (EOMs) are a highly specialized type of tissue with a wide range of unique properties, including characteristic innervation, development, and structural proteins. Even though EOMs are frequently and prominently affected by thyroid-associated diseases, little is known about the direct effects of thyroid hormone on these muscles. To create a comprehensive profile of changes in gene expression levels in EOMs induced by thyroid hormone, hyperthyroid conditions were simulated by treating adult Sprague-Dawley rats with intraperitoneal injections of the thyroid hormone 3,3′,5-triiodo-l-thyronine (T3); subsequently, microarray analysis was used to determine changes in mRNA levels in EOMs from T3-treated animals relative to untreated control animals. The expression of 468 transcripts was found to be significantly altered, with 466 of these transcripts downregulated in EOMs from T3-treated animals. The biological processes into which the affected genes could be grouped included cellular metabolism, transport, biosynthesis, protein localization, and cell homeostasis. Moreover, 15 distinct biochemical canonical pathways were represented among the genes with altered transcription levels. Strikingly, myostatin ( Gdf8), a potent negative regulator of muscle growth, was found to be strongly downregulated in EOMs from T3-treated animals. Together, these findings suggest that pathological concentrations of thyroid hormone have a unique effect on gene expression in EOMs, which is likely to play a hitherto neglected role in thyroid-associated ophthalmopathies.


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 757
Author(s):  
Valentina Ginevičienė ◽  
Audronė Jakaitienė ◽  
Erinija Pranckevičienė ◽  
Kazys Milašius ◽  
Algirdas Utkus

The MSTN gene is a negative regulator of muscle growth that is attracting attention as a candidate gene for physical performance traits. We hypothesised that variants of MSTN might be associated with the status of elite athlete. We therefore sought to study the potential role of MSTN in the physical performance of athletes by analysing the whole coding sequence of the MSTN gene in a cohort of Lithuanian elite athletes (n = 103) and non-athletes (n = 127). Consequently, two genetic variants were identified: the deletion of one of three adenines in the first intron (c.373+90delA, rs11333758) and a non-synonymous variant in the second exon (c.458A>G, p.Lys(K)153Arg(R), rs1805086). Among all samples, the MSTN rs1805086 Lys(K) allele was the most common form in both groups. Homozygous genotype for the less common Arg(R) allele was identified in only one elite canoe rower, and we could find no direct association between rs1805086 and successful results in elite athletes. Surprisingly, the intronic variant (rs11333758) was abundant among all samples. The main finding was that endurance-oriented athletes had 2.1 greater odds of being MSTN deletion genotype than non-athletes (13.6% vs. 0.8%). The present study confirms the association of the polymorphism rs11333758 with endurance performance status in Lithuanian elite athletes.


2009 ◽  
Vol 21 (1) ◽  
pp. 251
Author(s):  
K. Tessanne ◽  
T. Stroud ◽  
C. Long ◽  
G. Hannon ◽  
S. Sadeghieh ◽  
...  

RNA interference (RNAi) is a means of regulating gene expression by targeting mRNA in a sequence-specific manner for degradation or translational inhibition. Short hairpin RNAs (shRNAs) and siRNAs have been extensively employed for manipulating gene expression in a wide range of species. However, the great majority of this work has involved in vitro studies with cells grown in culture. Our goal for this project is to produce transgenic livestock in which myostatin, a negative regulator of muscle growth, has been targeted for silencing by RNAi. In theory, livestock in which myostatin has been silenced should exhibit increased muscle growth and development. To that end, we designed shRNAs to target the bovine myostatin mRNA sequence. The shRNAs were cloned into a lentiviral vector that contains a cytomegalovirus promoter controlling green fluorescent protein and shRNA expression as well as neomycin resistance. Infective lentivirus was made in HEK293T cells through co-transfection of the lentiviral vector, a packaging plasmid, and a plasmid expressing the VSVG pseudotype. Bovine fetal fibroblasts were transduced, selected using Geneticin®, and nuclear transfer was utilized to produce cloned transgenic embryos. There were 186 fusion attempts resulting in 160 fused embryos (fusion rate = 86%). Of these, 54 reached the blastocyst stage (34%) and 10 embryos were transferred into 5 recipient females (2 embryos per recipient). At 40 days, ultrasound revealed 1 confirmed pregnancy. Current plans are to harvest this fetus at 90 days and analyze it for evidence of myostatin knockdown. The production of transgenic animals exhibiting myostatin knockdown through lentiviral-mediated RNAi will demonstrate the utility of RNAi in the study of gene function in large animal models without the need for homologous recombination techniques, which are currently inefficient in species other than mice.


Genes ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 2 ◽  
Author(s):  
Ewa Grochowska ◽  
Bronisław Borys ◽  
Sławomir Mroczkowski

Myostatin acts as a negative regulator of muscle growth; therefore, its role is important with regard to animal growth and meat production. This study was undertaken with the objective to detect polymorphisms in the first intron and c.*1232 position of the MSTN gene and to analyze effects of the detected alleles/genotypes on growth and carcass traits in Colored Polish Merino sheep. In total, 23 traits were analyzed, i.e., seven describing lamb growth and 16 carcass traits. Single nucleotide polymorphisms (SNPs) in the first intron and the c.*1232 position were identified using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods, respectively. The MIXED procedure of the SAS software package was used to analyze allelic and genotypic effects of the MSTN gene on growth and carcass traits. Polymorphisms were only detected in the first intron of the MSTN gene. All investigated sheep were monomorphic G in the c.*1232 position. The MSTN genotype was found to have significant effect on body weight at 2nd day of life (BW2) and loin and fore shank weights. Significant allelic effects were detected with respect to BW2, scrag, leg, fore, and hind shank weights. These results suggest that polymorphisms in the first intron of the MSTN gene are relevant with respect to several carcass traits and BW2 in Colored Polish Merino sheep.


Endocrinology ◽  
2021 ◽  
Author(s):  
Ruizhong Wang ◽  
Poornima Bhat-Nakshatri ◽  
Xiaoling Zhong ◽  
Teresa Zimmers ◽  
Harikrishna Nakshatri

Abstract Cancer-induced skeletal muscle defects show sex-specific differences in severity with men performing poorly compared to women. Hormones and sex chromosomal differences are suggested to mediate these differences, but the functional skeletal muscle markers to document these differences are unknown. We show that the myogenic microRNA miR-486 is a marker of sex-specific differences in cancer-induced skeletal muscle defects. Cancer-induced loss of circulating miR-486 was more severe in men with bladder, lung and pancreatic cancers compared to women with the same cancer types. In syngeneic model of pancreatic cancer, circulating and skeletal muscle loss of miR-486 was more severe in male mice compared to female mice. Estradiol (E2) and the clinically used selective estrogen receptor modulator toremifene increased miR-486 in undifferentiated and differentiated myoblast cell line C2C12 and E2-inducible expression correlated with direct binding of estrogen receptor alpha (ERα) to the regulatory region of miR-486 gene. E2 and toremifene reduced the actions of cytokines such as myostatin, TGFβ and TNFα, which mediate cancer-induced skeletal muscle wasting. E2 and toremifene treated C2C12 myoblast/myotube cells contained elevated levels of active AKT with corresponding decrease in the levels of its negative regulator PTEN, which is a target of miR-486. We propose an ERα:E2-miR-486-AKT signaling axis, which reduces the deleterious effects of cancer-induced cytokines/chemokines on skeletal muscle mass and/or function.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 423
Author(s):  
Genxi Zhang ◽  
Mingliang He ◽  
Pengfei Wu ◽  
Xinchao Zhang ◽  
Kaizhi Zhou ◽  
...  

microRNAs play an important role in the growth and development of chicken embryos, including the regulation of skeletal muscle genesis, myoblast proliferation, differentiation, and apoptosis. Our previous RNA-seq studies showed that microRNA-27b-3p (miR-27b-3p) might play an important role in regulating the proliferation and differentiation of chicken primary myoblasts (CPMs). However, the mechanism of miR-27b-3p regulating the proliferation and differentiation of CPMs is still unclear. In this study, the results showed that miR-27b-3p significantly promoted the proliferation of CPMs and inhibited the differentiation of CPMs. Then, myostatin (MSTN) was confirmed to be the target gene of miR-27b-3p by double luciferase reporter assay, RT-qPCR, and Western blot. By overexpressing and interfering with MSTN expression in CPMs, the results showed that overexpression of MSTN significantly inhibited the proliferation and differentiation of CPMs. In contrast, interference of MSTN expression had the opposite effect. This study showed that miR-27b-3p could promote the proliferation of CPMs by targeting MSTN. Interestingly, both miR-27b-3p and MSTN can inhibit the differentiation of CPMs. These results provide a theoretical basis for further understanding the function of miR-27b-3p in chicken and revealing its regulation mechanism on chicken muscle growth.


Author(s):  
Huaming He ◽  
Jordi Denecker ◽  
Katrien Van Der Kelen ◽  
Patrick Willems ◽  
Robin Pottie ◽  
...  

Abstract Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Li-Yao Duan ◽  
Yan Liang ◽  
Wen-Ping Gong ◽  
Yong Xue ◽  
Jie Mi ◽  
...  

Abstract Background The traditional Chinese medicine NiuBeiXiaoHe (NBXH) extract and Chinese medicine preparation JieHeWan (JHW) exhibit anti-tuberculosis effects. The anti- tuberculosis effect of NBXH was compared with that of JHW to elucidate the mechanism of action of NBXH. Methods BALB/c mice aged 6-8 weeks were randomly divided into a normal control group, Tuberculosis (TB) model group, JHW treatment group, and NBXH treatment group. After 3 and 13 weeks of treatment, the therapeutic effect in each group was evaluated by comparing lung histopathology, lung and liver colony counts, the number of spots representing effector T cells secreting IFN-γ in an ELISPOT, and the levels of Th1, Th2, and Th17 cytokines, which were measured by a cytometric bead array (CBA). Mouse RNA samples were subjected to transcriptome sequencing. Results After 13 weeks of treatment, the mean histopathological lesion area of the NBXH group was significantly smaller than that of the TB model group (P < 0.05). Compared with those in the TB model group, the lung colony counts in the JHW and NBXH groups were significantly decreased (P < 0.05), and the IL-2 and IL-4 levels in the NBXH group were significantly increased (P < 0.05). NBXH partly restored significant changes in gene expression caused by Mycobacterium tuberculosis (M. tuberculosis) infection. According to GO and KEGG analyses, the changes in biological process (BP), cell composition (CC) and molecular function (MF) terms and in signaling pathways caused by NBXH and JHW treatment were not completely consistent, but they were mainly related to the immune response and inflammatory response in the mouse TB model. Conclusions NBXH had therapeutic effects similar to those of JHW in improving lung histopathology, reducing lung colony counts, and regulating the levels of cytokines. NBXH restored significant changes in gene expression and repaired cell damage caused by M. tuberculosis infection by regulating immune-related pathways, which clarified the mechanism of action of NBXH.


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