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Shift from androgen to estrogen action causes abdominal muscle fibrosis, atrophy, and inguinal hernia in a transgenic male mouse model. Proc Natl Acad Sci U S A 2018; 115:E10427-E10436. [PMID: 30327348 PMCID: PMC6217386 DOI: 10.1073/pnas.1807765115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Inguinal hernia is one of the most common disorders that affect elderly men. A major pathology underlying inguinal hernia is the fibrosis and other degenerative changes that affect the lower abdominal muscle strength adjacent to the inguinal canal. Here we describe a critical role of estrogen and its nuclear receptor that enhance fibroblast proliferation and muscle atrophy, leading to inguinal hernia. Further research may reveal a potential role of estrogen ablation to prevent muscle fibrosis or hernia in a subset of elderly men. Inguinal hernia develops primarily in elderly men, and more than one in four men will undergo inguinal hernia repair during their lifetime. However, the underlying mechanisms behind hernia formation remain unknown. It is known that testosterone and estradiol can regulate skeletal muscle mass. We herein demonstrate that the conversion of testosterone to estradiol by the aromatase enzyme in lower abdominal muscle (LAM) tissue causes intense fibrosis, leading to muscle atrophy and inguinal hernia; an aromatase inhibitor entirely prevents this phenotype. LAM tissue is uniquely sensitive to estradiol because it expresses very high levels of estrogen receptor-α. Estradiol acts via estrogen receptor-α in LAM fibroblasts to activate pathways for proliferation and fibrosis that replaces atrophied myocytes, resulting in hernia formation. This is accompanied by decreased serum testosterone and decreased expression of the androgen receptor target genes in LAM tissue. These findings provide a mechanism for LAM tissue fibrosis and atrophy and suggest potential roles of future nonsurgical and preventive approaches in a subset of elderly men with a predisposition for hernia development.
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Hermes TDA, Kido LA, Macedo AB, Mizobuti DS, Moraes LHR, Somazz MC, Cagnon VHA, Minatel E. Sex influences diaphragm muscle response in exercised mdx mice. Cell Biol Int 2018; 42:1611-1621. [PMID: 30238549 DOI: 10.1002/cbin.11057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/16/2018] [Indexed: 12/26/2022]
Abstract
Physical exercise promotes increased muscle damage in the mdx mice, the experimental model of Duchenne muscular dystrophy. Studies suggest that the estrogen level in females makes them less susceptible to muscle injuries. The aim of this study was to characterize the diaphragm (DIA) muscle response to physical exercise in male and female mdx mice. The animals were divided into four groups: female sedentary mdx; male sedentary mdx; female mdx submitted to exercise; and male mdx mice submitted to exercise. Blood samples were used to determine creatine kinase (CK). Regenerated muscle fibers were indicated by the presence of central nucleus and also inflammation areas were determined in DIA muscle sections. The alpha and beta estrogen receptors (ER) were determined by means of immunohistochemistry evaluation in the dystrophic DIA muscle. Male mdx animals submitted to exercise showed increased CK levels and inflammatory area. The quantification of regenerated fibers was higher in male animals, submitted or not to physical exercise. Greater alpha and beta ER expression was verified in the females submitted to exercise in the DIA muscle than in the other experimental groups. Therefore, estrogen may have contributed to the prevention of increased inflammatory process and DIA injury in females submitted to exercise.
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Affiliation(s)
- Túlio de Almeida Hermes
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil.,Centro Regional Universitário de Espírito Santo do Pinhal (UNIPINHAL), Espírito Santo do Pinhal, São Paulo 13990-000, Brazil
| | - Larissa Akemi Kido
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
| | - Aline Barbosa Macedo
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
| | - Daniela Sayuri Mizobuti
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
| | - Luiz Henrique Rapucci Moraes
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
| | - Marco Cesar Somazz
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil.,Centro Regional Universitário de Espírito Santo do Pinhal (UNIPINHAL), Espírito Santo do Pinhal, São Paulo 13990-000, Brazil
| | - Valéria Helena Alves Cagnon
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
| | - Elaine Minatel
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo 13083-970, Brazil
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Kim YJ, Tamadon A, Park HT, Kim H, Ku SY. The role of sex steroid hormones in the pathophysiology and treatment of sarcopenia. Osteoporos Sarcopenia 2016; 2:140-155. [PMID: 30775480 PMCID: PMC6372754 DOI: 10.1016/j.afos.2016.06.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/09/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
Sex steroids influence the maintenance and growth of muscles. Decline in androgens, estrogens and progesterone by aging leads to the loss of muscular function and mass, sarcopenia. These steroid hormones can interact with different signaling pathways through their receptors. To date, sex steroid hormone receptors and their exact roles are not completely defined in skeletal and smooth muscles. Although numerous studies focused on the effects of sex steroid hormones on different types of cells, still many unexplained molecular mechanisms in both skeletal and smooth muscle cells remain to be investigated. In this paper, many different molecular mechanisms that are activated or inhibited by sex steroids and those that influence the growth, proliferation, and differentiation of skeletal and smooth muscle cells are reviewed. Also, the similarities of cellular and molecular pathways of androgens, estrogens and progesterone in both skeletal and smooth muscle cells are highlighted. The reviewed signaling pathways and participating molecules can be targeted in the future development of novel therapeutics.
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Affiliation(s)
- Yong Jin Kim
- Department of Obstetrics and Gynecology, Korea University Guro Hospital, South Korea
| | - Amin Tamadon
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Hyun Tae Park
- Department of Obstetrics and Gynecology, Korea University Anam Hospital, Korea University College of Medicine, South Korea
| | - Hoon Kim
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Seung-Yup Ku
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
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Feder D, Rugollini M, Santomauro A, Oliveira LP, Lioi VP, Santos RD, Ferreira LG, Nunes MT, Carvalho MH, Delgado PO, Carvalho AAS, Fonseca FLA. Erythropoietin reduces the expression of myostatin in mdx dystrophic mice. ACTA ACUST UNITED AC 2014. [PMID: 25296358 PMCID: PMC4230286 DOI: 10.1590/1414-431x20143858] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Erythropoietin (EPO) has been well characterized as a renal glycoprotein hormone
regulating red blood cell production by inhibiting apoptosis of erythrocyte
progenitors in hematopoietic tissues. EPO exerts regulatory effects in cardiac and
skeletal muscles. Duchenne muscular dystrophy is a lethal degenerative disorder of
skeletal and cardiac muscle. In this study, we tested the possible therapeutic
beneficial effect of recombinant EPO (rhEPO) in dystrophic muscles in mdx mice. Total
strength was measured using a force transducer coupled to a computer. Gene expression
for myostatin, transforming growth factor-β1 (TGF-β1), and tumor necrosis factor-α
(TNF-α) was determined by quantitative real time polymerase chain reaction. Myostatin
expression was significantly decreased in quadriceps from mdx mice treated with rhEPO
(rhEPO=0.60±0.11, control=1.07±0.11). On the other hand, rhEPO had no significant
effect on the expression of TGF-β1 (rhEPO=0.95±0.14, control=1.05±0.16) and TNF-α
(rhEPO=0.73±0.20, control=1.01±0.09). These results may help to clarify some of the
direct actions of EPO on skeletal muscle.
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Affiliation(s)
- D Feder
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
| | - M Rugollini
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
| | - A Santomauro
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
| | - L P Oliveira
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
| | - V P Lioi
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
| | - R dos Santos
- Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
| | - L G Ferreira
- Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
| | - M T Nunes
- Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
| | - M H Carvalho
- Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
| | - P O Delgado
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
| | | | - F L A Fonseca
- Faculdade de Medicina do ABC, Santo André, SP, Brasil
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