Corticosteroid binding globulin (CBG; SERPINA6) binds >85% of circulating glucocorticoids but its influence on their metabolic actions is unproven. Targeted proteolytic cleavage of CBG by neutrophil elastase (NE; ELANE) significantly reduces CBG binding affinity, potentially increasing 'free' glucocorticoid levels at sites of inflammation. NE is inhibited by alpha-1-antitrypsin (AAT; SERPINA1).
View Article and Find Full Text PDFProduced by the liver, corticosteroid-binding globulin (CBG) regulates the plasma distribution and actions of glucocorticoids. A sex difference in pituitary growth hormone secretion patterns established during puberty in rats results in increased hepatic CBG production and 2-fold higher plasma corticosterone levels in females. Glucocorticoids control hepatic development and metabolic activities, and we have therefore examined how disrupting the SerpinA6 gene encoding CBG influences plasma corticosterone dynamics, as well as liver gene expression in male and female rats before and after puberty.
View Article and Find Full Text PDFEncoded by SerpinA6, plasma corticosteroid-binding globulin (CBG) transports glucocorticoids and regulates their access to cells. We determined how CBG influences plasma corticosterone and adrenal development in rats during the pubertal to adult transition using CRISPR/cas9 to disrupt SerpinA6 gene expression. In the absence of CBG, total plasma corticosterone levels were ∼80% lower in adult rats of both sexes, with a greater absolute reduction in females than in males.
View Article and Find Full Text PDFBrown bears are obese when they enter the den, and after 6 mo of hibernation and physical inactivity, bears show none of the adverse consequences of a sedentary lifestyle in humans, such as cardiovascular disease, type 2 diabetes, and kidney failure. The metabolic mechanisms that drive hibernation physiology in bears are poorly defined, but systemic endocrine regulators are likely involved. To investigate the potential role of steroid hormones, we quantified the total levels of 12 steroid hormones, the precursor cholesterol, sex hormone-binding globulin (SHBG), and corticosterone-binding globulin (CBG) in paired serum samples from subadult free-ranging Scandinavian brown bears during the active and hibernation states.
View Article and Find Full Text PDFSex hormone-binding globulin (SHBG) regulates the bioavailability of sex steroid hormones in the blood. Levels of SHBG increase markedly in brown bears (Ursus arctos) during hibernation, suggesting that a key regulatory role of this protein is to quench sex steroid bioavailability in hibernation physiology. To enable characterization of ursine SHBG and a cross species comparison, we established an insect cell-based expression system for recombinant full-length ursine and human SHBG.
View Article and Find Full Text PDFSex hormone-binding globulin (SHBG) in the blood is a major determinant of bioactivity for key sex steroids such as testosterone and estradiol. Low serum levels of SHBG have been associated with obesity, polycystic ovaries, and metabolic syndrome, and other states associated with hyperandrogenemia. A 9-year, 6-month-old girl presented with a history of peripheral precocious puberty and aggressive behavior.
View Article and Find Full Text PDFBMJ Open
February 2021
Normal function of the hypothalamic-pituitary-adrenal (HPA) axis is critical for survival, and its development is choreographed for age-, sex- and context-specific actions. The liver influences HPA ontogeny, integrating diverse endocrine signals that inhibit or activate its development. This review examines how developmental changes in the expression of genes in the liver coordinate postnatal changes in multiple endocrine systems that facilitate the maturation and sexual dimorphism of the rat HPA axis.
View Article and Find Full Text PDFSex hormone-binding globulin (SHBG) determines the equilibrium between free and protein-bound androgens and estrogens in the blood and regulates their access to target tissues. Using crystallographic approaches and radiolabeled competitive binding-capacity assays, we report here how two nonsteroidal compounds bind to human SHBG, and how they influence androgen activity in cell culture. We found that one of these compounds, (-)3,4-divanillyltetrahydrofuran (DVT), present in stinging nettle root extracts and used as a nutraceutical, binds SHBG with relatively low affinity.
View Article and Find Full Text PDFObjective: Discrepancies in ELISA measurements of human corticosteroid-binding globulin (CBG) using detection monoclonal antibodies that recognize an epitope (9G12) within its reactive center loop (RCL), versus an epitope (12G2) in a different location, have suggested that CBG with a proteolytically cleaved RCL exists in blood samples. We have previously been unable to verify this biochemically, and sought to determine if N-glycosylation differences account for discrepancies in ELISA measurements of CBG.
Methods And Subjects: Molecular biological, biochemical and glycopeptide analyses were used to examine how N-glycosylation at specific sites, including at N347 within the RCL, affect CBG ELISA or steroid-binding capacity assay (BCA) measurements.
The effect of perinatal selective serotonin reuptake inhibitors (SSRIs) on brain-derived neurotrophic factor (BDNF) and S100 calcium binding protein B (S100B) has not been investigated. Using a cohort of 86 pregnant women, we found that SSRIs significantly increase BDNF levels in late pregnancy and that S100B, but not BDNF, is associated with maternal depression in SSRI-treated women only. This shows that serum S100B could be a unique biomarker to determine efficacy of SSRIs during gestation.
View Article and Find Full Text PDFIn the present study, we determined the hepatopancratic shbg transcript abundance and ovarian immunoreactive Shbg (ir-Shbg) localization in pejerrey females at different gonadal stages during an annual ovarian cycle. In the hepatopancreas, shbg expression remains was constant in pre-vitellogenic stages, decreased at final vitellogenesis to increase again in final maturation and atretic stages to previous levels at post-vitellogenic stages. Related to this, also we found a negative significant relation between sex steroid and shbg expression.
View Article and Find Full Text PDFCorticosteroid-binding globulin (CBG) transports glucocorticoids in blood and is a serine protease inhibitor family member. Human CBG has a reactive center loop (RCL) which, when cleaved by neutrophil elastase (NE), disrupts its steroid-binding activity. Measurements of CBG levels are typically based on steroid-binding capacity or immunoassays.
View Article and Find Full Text PDFA correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
View Article and Find Full Text PDFBackground: Human fetal adrenal glands are highly active and, with the placenta, regulate circulating progesterone, estrogen and corticosteroids in the fetus. At birth the adrenals are essential for neonate salt retention through secretion of aldosterone, while adequate glucocorticoids are required to prevent adrenal insufficiency. The objective of this study was to carry out the first comprehensive analysis of adrenal steroid levels and steroidogenic enzyme expression in normal second trimester human fetuses.
View Article and Find Full Text PDFJ Mol Endocrinol
February 2018
Corticosteroid-binding globulin (CBG) is a plasma carrier of glucocorticoids. Human and rat CBGs have six -glycosylation sites. Glycosylation of human CBG influences its steroid-binding activity, and there are -glycosylation sites in the reactive center loops (RCLs) of human and rat CBGs.
View Article and Find Full Text PDFThere is increasing evidence that mental health concerns, stress-related mental illnesses, and parental stress prior to conception have long-term effects on offspring outcomes. However, more work is needed to understand how pre-gestational stress might affect neurobehavioral outcomes in the mother. We investigated how chronic stress prior to gestation affects maternal behavior and related physiology, and aimed to determine the role that perinatal SSRIs have in altering these stress effects.
View Article and Find Full Text PDFBackground: Sex hormone-binding globulin (SHBG) is the main transporter of sex hormones in most vertebrates. Low SHBG levels have been linked to increased risk for diabetes and metabolic syndrome. Polymorphisms of the gene linked to low SHBG protein levels also strongly predicted increased risk of type 2 diabetes, thus raising the possibility that SHBG may play a role in the pathogenesis of insulin resistance and diabetes.
View Article and Find Full Text PDFSex hormone-binding globulin (SHBG) carries sex steroids in blood regulating their bioavailability. Red wine consumption increases plasma SHBG levels, and we have discovered that resveratrol, a polyphenol enriched in red wine, acts specifically through the human constitutive androstane receptor (CAR), a drug/xenobiotic detoxification gene regulator, to increase hepatic SHBG production. Chromatin immunoprecipitation and luciferase reporter gene assays show that human CAR binds to a typical direct repeat 1 nuclear hormone receptor-binding element in the human SHBG proximal promoter.
View Article and Find Full Text PDFAfter completing 5 years of adjuvant tamoxifen, women with estrogen receptor (ER)-positive breast cancer benefit from 5 more years of endocrine therapy, either with tamoxifen or an aromatase inhibitor (AI). For premenopausal women, ovarian ablation (OA) would be required before starting an AI (OA/AI). According to the SOFT/TEXT studies, OA/AI improves 5-year disease-free survival compared with tamoxifen alone, suggesting that OA/AI could be superior to tamoxifen as extended endocrine therapy.
View Article and Find Full Text PDFSelective serotonin reuptake inhibitor medications (SSRIs) are the first lines of treatment for maternal affective disorders, and are prescribed to up to 10% of pregnant women. Concern has been raised about how perinatal exposure to these medications affect offspring neurobehavioral outcomes, particularly those related to social interactions, as recent research has reported conflicting results related to autism spectrum disorder (ASD) risk in children prenatally exposed to SSRIs. Therefore, the aim of this work was to investigate the effects of perinatal exposure to the SSRI fluoxetine on social play behaviors and the hypothalamic pituitary adrenal system, using a model of pre-gestational maternal stress.
View Article and Find Full Text PDFHistorically, ovarian ablation (OA) was used as therapy for women with recurrent hormone-receptor-positive (HRP) premenopausal breast cancer. With the publication of the SOFT (Suppression of Ovarian Function Trial) and TEXT (Tamoxifen and Exemestane Trial) randomized trials, there is considerable interest in OA as an adjuvant treatment, either in combination with tamoxifen or an aromatase inhibitor (AI). Thus, we have reviewed current guidelines and key studies on this important topic and have highlighted the relevant biological and pharmacological aspects of the various endocrine therapies.
View Article and Find Full Text PDFSex hormone binding globulin (Shbg) is a plasma glycoprotein that binds and transports steroids in the blood of all vertebrate classes apart from birds. In the present study we characterized shbg from pejerrey, a fish species with a well characterized temperature-dependent sex determination. The pejerrey shbg mRNA comprises 1185bp encoding for a 395 amino acid Shbg precursor protein that includes a leader sequence for secretion.
View Article and Find Full Text PDFSex hormone-binding globulin (SHBG) is the high-affinity binding protein for androgens and estrogens. According to the free hormone hypothesis, SHBG modulates the bioactivity of sex steroids by limiting their diffusion into target tissues. Still, the in vivo physiological role of circulating SHBG remains unclear, especially since mice and rats lack circulating SHBG post-natally.
View Article and Find Full Text PDFBiochemical assessments of androgen status (hyper- or hypoandrogenism) are usually based on serum testosterone concentrations. According to the free hormone hypothesis, sex hormone-binding globulin (SHBG) determines free and bioavailable testosterone concentrations. Previous studies have suggested that in vitro androgen bioassay results may also be influenced by SHBG and correlate with free or bioavailable testosterone concentrations.
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