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Basualto-Alarcón C, Llanos P, García-Rivas G, Troncoso MF, Lagos D, Barrientos G, Estrada M. Classic and Novel Sex Hormone Binding Globulin Effects on the Cardiovascular System in Men. Int J Endocrinol 2021; 2021:5527973. [PMID: 34335746 PMCID: PMC8318754 DOI: 10.1155/2021/5527973] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 12/16/2022] Open
Abstract
In men, 70% of circulating testosterone binds with high affinity to plasma sex hormone binding globulin (SHBG), which determines its bioavailability in their target cells. In recent years, a growing body of evidence has shown that circulating SHBG not only is a passive carrier for steroid hormones but also actively regulates testosterone signaling through putative plasma membrane receptors and by local expression of androgen-binding proteins apparently to reach local elevated testosterone concentrations in specific androgen target tissues. Circulating SHBG levels are influenced by metabolic and hormonal factors, and they are reduced in obesity and insulin resistance, suggesting that SHBG may have a broader clinical utility in assessing the risk for cardiovascular diseases. Importantly, plasma SHBG levels are strongly correlated with testosterone concentrations, and in men, low testosterone levels are associated with an adverse cardiometabolic profile. Although obesity and insulin resistance are associated with an increased incidence of cardiovascular disease, whether they lead to abnormal expression of circulating SHBG or its interaction with androgen signaling remains to be elucidated. SHBG is produced mainly in the liver, but it can also be expressed in several tissues including the brain, fat tissue, and myocardium. Expression of SHBG is controlled by peroxisome proliferator-activated receptor γ (PPARγ) and AMP-activated protein kinase (AMPK). AMPK/PPAR interaction is critical to regulate hepatocyte nuclear factor-4 (HNF4), a prerequisite for SHBG upregulation. In cardiomyocytes, testosterone activates AMPK and PPARs. Therefore, the description of local expression of cardiac SHBG and its circulating levels may shed new light to explain physiological and adverse cardiometabolic roles of androgens in different tissues. According to emerging clinical evidence, here, we will discuss the potential mechanisms with cardioprotective effects and SHBG levels to be used as an early metabolic and cardiovascular biomarker in men.
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Affiliation(s)
- Carla Basualto-Alarcón
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique 5951537, Chile
- Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Paola Llanos
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Gerardo García-Rivas
- Tecnológico de Monterrey, Hospital Zambrano Hellion, TecSalud, Centro de Medicina Funcional, San Pedro Garza García, Nuevo León 66278, Mexico
| | - Mayarling Francisca Troncoso
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Daniel Lagos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Genaro Barrientos
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
| | - Manuel Estrada
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8389100, Chile
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Bhatnager R, Senwal A, Nanda S, Dang AS. Association of rs6259 polymorphism with SHBG levels and Poly Cystic Ovary Syndrome in Indian population: a case control study. Mol Biol Rep 2019; 46:2131-2138. [PMID: 30719605 DOI: 10.1007/s11033-019-04665-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 01/30/2019] [Indexed: 01/15/2023]
Abstract
Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. PCOS reflects a number of possible etiologies but its pathophysiology is still unclear. The principal abnormality of the syndrome is hyperandrogenism (70-80%). The access of androgens to target tissues is regulated by sex hormone-binding globulin (SHBG), a transport protein secreted by liver i.e. specific for androgens. Present study was done to find the association of rs6259 polymorphism with SHBG levels and Poly Cystic Ovary Syndrome in Indian population. Present study was a case control study. 400 subjects were enrolled for the study and serum SHBG levels and D327N polymorphism were measured. The D327N polymorphism (wild-type and variant allele) was detected using PCR-RFLP method (restriction enzyme Bbs-I). PCOS group was found to have significantly lower SHBG levels than healthy controls. There was no significant difference in genotype distribution between PCOS and controls (χ2 = 1.0335, p = 0.59). Significant difference in SHBG levels of PCOS and control group highlights the potential of SHBG as a biomarker for PCOS. However, no significant difference in genotype distribution between PCOS and controls provided an insight that rs6259 polymorphism is not associated with the risk of PCOS and SHBG levels.
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Affiliation(s)
- Richa Bhatnager
- Centre for Medical Biotechnology, Maharshi Dayanand University, Rohtak, 124001, India
| | - Alka Senwal
- Centre for Medical Biotechnology, Maharshi Dayanand University, Rohtak, 124001, India
| | - Smiti Nanda
- Pandit Bhagwat Dayal Sharma Institute of Medical Sciences, Rohtak, 124001, India
| | - Amita S Dang
- Centre for Medical Biotechnology, Maharshi Dayanand University, Rohtak, 124001, India.
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