Sex hormone-binding globulin

Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it is called androgen-binding protein (ABP).[5][6]

SHBG
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
AliasesSHBG, ABP, SBP, TEBG, sex hormone binding globulin, Sex hormone-binding globulin
External IDsOMIM: 182205; MGI: 98295; HomoloGene: 813; GeneCards: SHBG; OMA:SHBG - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_011367

RefSeq (protein)

NP_035497

Location (UCSC)Chr 17: 7.61 – 7.63 MbChr 11: 69.51 – 69.51 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse
Androgen-binding protein, Sex hormone-binding globulin
Identifiers
SymbolSHBG
Alt. symbolsABP
NCBI gene6462
HGNC10839
OMIM182205
RefSeqNM_001040
UniProtP04278
Other data
LocusChr. 17 p13-p12
Search for
StructuresSwiss-model
DomainsInterPro

Other steroid hormones such as progesterone, cortisol, and other corticosteroids are bound by transcortin. SHBG is found in all vertebrates apart from birds.[7]

Function

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Testosterone and estradiol circulate in the bloodstream, loosely bound mostly to serum albumin (~54%), and to a lesser extent bound tightly to SHBG (~44%). Only a very small fraction of about 1 to 2% is unbound, or "free," and thus biologically active and able to enter a cell and activate its receptor. SHBG inhibits the function of these hormones. Thus, the local bioavailability of sex hormones is influenced by the level of SHBG. Because SHBG binds to testosterone (T) and dihydrotestosterone (DHT), these hormones are made less lipophilic and become concentrated within the luminal fluid of the seminiferous tubules. The higher levels of these hormones enable spermatogenesis in the seminiferous tubules and sperm maturation in the epididymis. SHBG’s production is regulated under the influence of FSH[6] on Sertoli cells, enhanced by insulin, retinol, and testosterone.

The relative binding affinity of various sex steroids for SHBG is dihydrotestosterone (DHT) > testosterone > androstenediol > estradiol > estrone.[8] DHT binds to SHBG with about 5 times the affinity of testosterone and about 20 times the affinity of estradiol.[9] Dehydroepiandrosterone (DHEA) is weakly bound to SHBG, but dehydroepiandrosterone sulfate is not bound to SHBG.[8] Androstenedione is not bound to SHBG either, and is instead bound solely to albumin.[10] Estrone sulfate and estriol are also poorly bound by SHBG.[11] Less than 1% of progesterone is bound to SHBG.[12]

SHBG levels are usually about twice as high in women as in men.[9] In women, SHBG serves to limit exposure to both androgens and estrogens.[9] Low SHBG levels in women have been associated with hyperandrogenism and endometrial cancer due to heightened exposure to androgens and estrogens, respectively.[9] During pregnancy, due to activation of SHBG production in the liver by high estrogen levels, SHBG levels increase by five-fold to ten-fold.[9] The high SHBG levels during pregnancy may serve to protect the mother from exposure to fetal androgens that escape metabolism by the placenta.[9] A case report of severe hyperandrogenism in a pregnant woman due to a rare instance of genetic SHBG deficiency illustrates this.[9][13]

Biochemistry

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Biosynthesis

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SHBG is produced mostly by the liver and is released into the bloodstream. Other sites that produce SHBG include the brain, uterus, testes, and placenta.[14] Testes-produced SHBG is called androgen-binding protein.

Gene

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The gene for SHBG is called Shbg located on chromosome 17[14] on the short arm between the bands 17p12→p13.[15] Overlapping on the complementary DNA strand is the gene for spermidine/spermine N1-acetyltransferase family member 2 (SAT2). Nearby are the genes for p53 and ATP1B2, and fragile X mental retardation, autosomal homolog 2 (FXR2) on the complementary strand.[16] There are eight exons, of which exon 1 has three variations called 1L, 1T and 1N which are triggered by three promoters: PL, PT and PN respectively. SHBG comes with the 1L, 2, 3, 4, 5, 6, 7, and 8 exons connected together. A variation includes SHBG-T which is missing exon 7 but with exon 1T promoted by promoter PT on the opposite strand, which shared with that for SAT2.[17]

Polymorphisms

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There are variations in the genetic material for this protein that have different effects. In humans common polymorphisms include the following:

Rs6259, also called Asp327Asn location 7633209 on Chromosome 17, results in there being an extra N-glycosilation site, and so an extra sugar can be attached. This results in a longer circulation half-life for the protein, and raised levels. A health effect is a lowered risk of endometrial cancer, and another is an increased risk of systemic lupus erythematosus.[18]

Rs6258 also called Ser156Pro is at position 7631360 on the Chromosome 17.

Rs727428 position 7634474 is in several percent of humans.[19]

(TAAAA)(n) is five base pairs that repeats a variable number of times on the opposite DNA strand.[20]

Promoter activation

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The mechanism of activating the promoter for SHBG in the liver involves hepatocyte nuclear factor 4 alpha (HNF4A) binding to a DR1 like cis element which then stimulate production. Competing with HNF4A at a third site on the promoter is PPARG-2 which reduces copying the gene to RNA. If HNF4A level is low then COUP-TF binds to the first site and turns off production of SHBG.[7]

Protein

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Sex hormone-binding globulin is homodimeric, meaning it has two identical peptide chains making up its structure. The amino acid sequence is the same as for androgen-binding protein but that has different oligosaccharides attached and is produced in testes.[14]

SHBG has two laminin G-like domains which form pockets that bind hydrophobic molecules. The steroids are bound by the LG domain at the amino end of the protein.[7] Inside the pocket of the domain is a serine residue that attracts the two different types of steroids at different points, thus changing their orientation. Androgens bind at the C3 functional groups on the A ring, and estrogens bind via a hydroxyl attached to C17 on the D ring. The two different orientations change a loop over the entrance to the pocket and the position of trp84 (in humans). Thus the whole protein signals what hormone it carries on its own surface.[7] The steroid binding LG domain is coded by exons 2 to 5.[7] A linker region joins the two LG domains together.[7]

When first produced the SHBG precursor has a leading signal peptide attached with 29 amino acids. The remaining peptide has 373 amino acids.[21] There are two sulfur bridges.

The sugars are attached at two different N-glycosylation points on asparagine (351 and 367) and one O-glycosylation (7) point on threonine.[21]

Metals

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A calcium ion is needed to link the two elements of the dimer together. Also a zinc ion is used to orient an otherwise disorganised part of the peptide chain.[7]

Regulation

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SHBG has both enhancing and inhibiting hormonal influences thus can be viewed as a hepatokine. It decreases with high levels of insulin, growth hormone, insulin-like growth factor 1 (IGF-1), androgens, prolactin and transcortin. High estrogen and thyroxine levels cause it to increase.

In an effort to explain obesity-related reductions in SHBG, recent evidence suggests sugar or monosaccharide-induced hepatic lipogenesis, hepatic lipids in general, and cytokines like TNF-alpha and Interleukin reduce SHBG, whereas insulin does not. As an example anti-psoriatic drugs that inhibit TNF-alpha cause an increase in SHBG. The common downstream mechanism for all of these, including the effect of thyroid hormones[22] was downregulation of HNF4, hepatocyte nuclear factor 4.[23][24][25][26]

Blood values

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Reference ranges for blood tests for SHBG have been developed:[27][28]

Population Range
Adult female, premenopausal 40–120 nmol/L
Adult female, postmenopausal 28–112 nmol/L
Adult male 20–60 nmol/L
Infant (1–23 months) 60–252 nmol/L
Prepubertal (2 years–8 years) 72–220 nmol/L
Pubertal female 36–125 nmol/L
Pubertal male 16–100 nmol/L

Clinical significance

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High or low levels

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Levels of sex hormones and SHBG during pregnancy in women.[29]
 
Levels of SHBG and estradiol during pregnancy in women.[30] For SHBG the lines are the mean and 95th percentile levels while the points are individual measurements.[30] For estradiol the line is the mean level.[30] The dashed parts of the lines are extrapolated.[30]
 
SHBG binding capacity during pregnancy in women.[31]

SHBG levels are decreased by androgens, administration of anabolic steroids,[32] polycystic ovary syndrome, hypothyroidism, obesity, Cushing's syndrome, and acromegaly. Low SHBG levels increase the probability of Type 2 Diabetes.[33] SHBG levels increase with estrogenic states (oral contraceptives), pregnancy, hyperthyroidism, cirrhosis, anorexia nervosa, and certain drugs. Long-term calorie restriction increases SHBG in rodents and men, while lowering free and total testosterone and estradiol and having no effect on DHEA-S, which lacks affinity for SHBG.[34] Polycystic Ovarian Syndrome is associated with insulin resistance and excess insulin lowers SHBG, which increases free testosterone levels.[35]

In the womb the human fetus has a low level of SHBG allowing increased activity of sex hormones. After birth, the SHBG level rises and remains at a high level throughout childhood. At puberty the SHBG level halves in girls and goes down to a quarter in boys.[7] The change at puberty is triggered by growth hormone, and its pulsatility differs in boys and girls.[clarification needed] In pregnant women in the third trimester of pregnancy the SHBG level escalates to five to ten times the usual level for a woman.[7][9] A hypothesis is that this protects against the effect of hormone produced by the fetus.[7]

Obese girls are more likely to have an early menarche due to lower levels of SHBG.[7] Anorexia or a lean physique in women leads to higher SHBG levels, which in turn can lead to amenorrhea.[7]

Type 2 diabetes

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Reduced levels of SHBG and also certain polymorphisms of the SHBG gene are implicated in the development of insulin resistance and type 2 diabetes.[36] Such effects apparently involve direct action at the cellular level where it became apparent that cell membranes of certain tissues contain specific high-affinity SHBG receptors.[37]

Coagulation

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SHBG is a useful correlate and indirect marker of estrogen-induced procoagulation and by extension thrombosis, for instance with birth control pills.[38][39][40]

Medications

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Oral contraceptives containing ethinylestradiol can increase SHBG levels by 2- to 4-fold and decrease free testosterone concentrations by 40 to 80% in women.[41] They can be used to treat symptoms of hyperandrogenism like acne and hirsutism.[41][9] Some oral contraceptives, namely those containing high doses of ethinylestradiol (which have been discontinued and are no longer marketed), can increase SHBG levels by as much as 5- to 10-fold.[9]

Some medications, such as certain anabolic steroids like mesterolone and danazol and certain progestins like levonorgestrel and norethisterone, have high affinity for SHBG and can bind to it and displace endogenous steroids from it, thereby increasing free concentrations of these endogenous steroids.[42][43][44] It has been estimated that therapeutic levels of danazol, methyltestosterone, fluoxymesterone, levonorgestrel, and norethisterone would respectively occupy or displace from testosterone 83–97%, 48–69%, 42–64%, 16–47%, and 4–39% of SHBG binding sites, while others with low affinity for SHBG such as ethinylestradiol, cyproterone acetate, and medroxyprogesterone acetate would occupy or displace from testosterone 1% or fewer SHBG binding sites.[42][45]

Selective androgen receptor modulators (SARMs) also reduce SHBG.[46]

Affinities of 70 medications for SHBG and CBG[42]
Compound Structure SHBG
RBA (%)
SHBG
K (106 M−1)
CBG
RBA (%)
CBG
K (106 M−1)
Aminoglutethimide Nonsteroidal <0.01 <0.2 <0.1 <0.1
Androstanolone Steroidal 220 5500 1.3 0.83
Betamethasone Steroidal <0.01 <0.2 <0.1 <0.1
Cholecalciferol Steroidal <0.01 <0.2 <0.1 <0.1
Cimetidine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Clomifene Nonsteroidal <0.01 <0.2 <0.1 <0.1
Cortisol (hydrocortisone) Steroidal 0.13 1.6 100 76
Cortisone acetate Steroidal 0.10 1.2 <0.1 <0.1
Cyproterone acetate Steroidal 0.10 1.2 <0.1 <0.1
Danazol Steroidal 18 240 10 6.5
Dexamethasone Steroidal <0.01 <0.2 <0.1 <0.1
Diazoxide Nonsteroidal <0.01 <0.2 <0.1 <0.1
Diethylstilbestrol Nonsteroidal <0.01 <0.2 <0.1 <0.1
Digitoxin Steroidal <0.01 <0.2 <0.1 <0.1
Digoxin Steroidal <0.01 <0.2 <0.1 <0.1
DL-DOPA Nonsteroidal <0.01 <0.2 <0.1 <0.1
Dopamine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Enclomiphene Nonsteroidal <0.01 <0.2 <0.1 <0.1
Epinephrine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Estradiol Steroidal 49 680 <0.1 <0.1
Estradiol benzoate Steroidal 0.70 8.6 <0.1 <0.1
Ethinylestradiol Steroidal 0.80 9.9 <0.1 <0.1
Ethisterone Steroidal 55 780 0.33 0.21
Fludrocortisone Steroidal <0.01 <0.2 0.74 0.47
Fluoxymesterone Steroidal 4.8 60 <0.1 <0.1
Flutamide Nonsteroidal <0.01 <0.2 <0.1 <0.1
Homovanillic acid Nonsteroidal <0.01 <0.2 <0.1 <0.1
Hydrocortisone hemisuccinate Steroidal <0.01 <0.2 8.7 5.6
Indometacin Nonsteroidal <0.01 <0.2 <0.1 <0.1
Levonorgestrel Steroidal 31 420 <0.1 <0.1
Medroxyprogesterone Steroidal 0.15 1.9 13 8.1
Medroxyprogesterone acetate Steroidal 0.08 1.0 6.5 4.2
Melatonin Nonsteroidal <0.01 <0.2 <0.1 <0.1
Mesterolone Steroidal 180 3600 <0.1 <0.1
Mestranol Steroidal <0.01 <0.2 <0.1 <0.1
Methoxytryptophol Nonsteroidal <0.01 <0.2 <0.1 <0.1
Methyldopa Nonsteroidal <0.01 <0.2 <0.1 <0.1
Methylserotonin Nonsteroidal <0.01 <0.2 <0.1 <0.1
Methyltestosterone Steroidal 39 530 <0.1 <0.1
Metiamide Nonsteroidal <0.01 <0.2 <0.1 <0.1
Metribolone Steroidal 1.7 21 0.36 0.23
Metyrapone Nonsteroidal <0.01 <0.2 <0.1 <0.1
Mexrenone Steroidal <0.01 <0.2 <0.1 <0.1
Nafoxidine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Nandrolone Steroidal 5.8 72 0.10 0.63
Norepinephrine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Norethisterone Steroidal 11 140 0.28 0.18
Noretynodrel Steroidal 1.3 16 0.16 0.10
Normetanephrine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Phenytoin Nonsteroidal <0.01 <0.2 <0.1 <0.1
Potassium canrenoate Steroidal 0.18 2.2 0.83 0.53
Prednisolone Steroidal 0.04 0.49 59 41
Prednisone Steroidal 0.17 2.1 5.0 3.2
Progesterone Steroidal 0.71 8.8 36 24
Promegestone Steroidal 0.007 0.09 0.40 0.25
Prorenone Steroidal 8.2 100 <0.1 <0.1
Reserpine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Rifampin Nonsteroidal <0.01 <0.2 <0.1 <0.1
Serotonin Nonsteroidal <0.01 <0.2 <0.1 <0.1
Spironolactone Steroidal 0.03 0.37 <0.1 <0.1
Tamoxifen Nonsteroidal <0.01 <0.2 <0.1 <0.1
Testolactone Steroidal <0.01 <0.2 <0.1 <0.1
Testosterone Steroidal 100 1600 8.3 5.3
Testosterone enanthate Steroidal 0.007 0.086 <0.1 <0.1
7α-Thioprogesterone Steroidal 0.06 0.74 36 24
7α-Thiospironolactone Steroidal 0.59 7.3 <0.1 <0.1
Thyroxine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Triiodothyronine Nonsteroidal <0.01 <0.2 <0.1 <0.1
Trimethyltrienolone Steroidal 0.90 11 0.11 0.07
Vanillylmandelic acid Nonsteroidal <0.01 <0.2 <0.1 <0.1
Zuclomifene Nonsteroidal <0.01 <0.2 <0.1 <0.1
The reference ligands (100%) for the RBATooltip relative binding affinity (%) values were testosterone for SHBG and cortisol for CBGTooltip corticosteroid-binding globulin.
Affinities of 21 progestins for SHBG and CBG[44][47]
Progestogen SHBG (%) CBG (%)
17α-Allyl-19-nortestosterone <1 ?
Allylestrenol <1 ?
Chlormadinone acetate <1 <1
Cyproterone acetate <1 <1
Desogestrel <1 <1
Dienogest <1 <1
Drospirenone <1 <1
Etonogestrel 15 <1
Gestodene 40 <1
Levonorgestrel 50 <1
Medroxyprogesterone acetate <1 <1
Megestrol acetate <1 <1
Nomegestrol acetate <1 <1
Norelgestromin <1 ?
Norethisterone 16 <1
Noretynodrel <1 <1
Norgestimate <1 <1
Progesterone <1 36
Promegestone <1 <1
Segesterone acetate <1 ?
Δ4-Tibolone 1 <1
Values are RBAsTooltip relative binding affinities (%). The reference ligand (100%) for SHBG was dihydrotestosterone and for CBGTooltip corticosteroid-binding globulin was cortisol.
Affinities of 14 AAS for SHBG[43]
Compound SHBG (%)
5α-Androstane-3β,17β-diol 17
5β-Androstane-3α,17β-diol 5
Dihydrotestosterone 100
Ethylestrenol <1
Fluoxymesterone <1
Mesterolone 440
Metandienone 2
Metenolone 3
Methyltestosterone 5
Metribolone <1
Nandrolone 1
Oxymetholone <1
Stanozolol 1
Testosterone 19
Values are RBAsTooltip relative binding affinities (%). The reference ligand (100%) for SHBG was dihydrotestosterone.
Affinities of 41 steroids for SHBG[48]
Compound SHBG (%)
3β-Androstanediol 100
Androstenediol 77
Bolandiol 24
Dihydroethisterone 100
Dihydroethyltestosterone 18–21
Dihydromethylandrostenediol 77
Dihydronandrolone 44
Dihydrotestosterone 100
Dihydrotrestolone 47
4,17α-Dimethyltestosterone 97
Drostanolone 39
Ethisterone 92
Fluoxymesterone 3
11-Ketodihydrotestosterone 0
Medroxyprogesterone acetate 16
Megestrol acetate 0
Mestanolone 84
Methasterone 58
Methyl-1-testosterone 69
Methylandrostenediol 40
Methyltestosterone 64
Mibolerone 6
Nandrolone 16
Nandrolone decanoate 0
Nandrolone phenylpropionate 0
Norethandrolone 3
Norethisterone 21
Normethandrone 7
Oxandrolone 0
Oxymetholone 3
Progesterone 13
Stanozolol 36
1-Testosterone 98
Testosterone 82
Testosterone benzoate 8
Testosterone cypionate 6
Testosterone enanthate 9
Δ4-Tibolone 8
Trestolone 12
Trestolone enanthate 12
Vinyltestosterone 36
Values are RBAsTooltip relative binding affinities (%). The reference ligand (100%) for SHBG was dihydrotestosterone.
Affinities of 11 steroids for SHBG and CBG[49]
Compound SHBGTooltip Sex hormone-binding globulin (%) CBGTooltip Corticosteroid binding globulin (%)
Aldosterone <0.2 6.0
Corticosterone <0.2 107
Cortisol <0.2 100
Dexamethasone <0.2 <0.1
Dihydrotestosterone 100 0.8
Estradiol 8.7 <0.1
Metribolone 0.2 <0.1
Moxestrol <0.2 <0.1
Progesterone <0.2 25
Promegestone <0.2 0.9
Testosterone 26 3
Values are RBAsTooltip relative binding affinities (%). The reference ligand (100%) for SHBG was dihydrotestosterone and for CBGTooltip corticosteroid-binding globulin was cortisol.
Affinities of 9 estrogens for SHBG[44][50]
Compound RBATooltip Relative binding affinity to
SHBGTooltip sex hormone-binding globulin (%)
Bound to
SHBG (%)
Bound to
albumin (%)
17β-Estradiol 50 37 61
Estrone 12 16 80
Estriol 0.3 1 91
Estrone sulfate 0 0 99
17β-Dihydroequilin 30 ? ?
Equilin 8 26 13
17β-Dihydroequilin sulfate 0 ? ?
Equilin sulfate 0 ? ?
Δ8-Estrone ? ? ?
The reference ligand (100%) for the SHBG RBATooltip relative binding affinity (%) values was testosterone.

Endogenous steroids

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Measurement

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When checking serum estradiol or testosterone, a total level that includes free and bound fractions can be assayed, or the free portion may be measured alone. Sex hormone-binding globulin can be measured separately from the total fraction of testosterone.

A free androgen index expresses the ratio of testosterone to SHBG and can be used to summarize the activity of free testosterone.

Affinity and binding

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Affinities of endogenous steroids for SHBG and plasma protein binding[51]
Steroid SHBG affinity Plasma protein binding in men Plasma protein binding in women (follicular phase)
RBA (%) K (106 M−1) Total (nM) Unbound (%) SHBG (%) CBG (%) Albumin (%) Total (nM) Unbound (%) SHBG (%) CBG (%) Albumin (%)
Aldosterone 0.017 0.21 0.35 37.1 0.10 21.2 41.6 0.24 36.8 0.23 21.9 41.2
3α-Androstanediol 82 1300 0.41 0.85 13.7 <0.1 85.5 0.068 0.71 27.9 <0.1 71.4
Androstenediol 97 1500 4.3 3.24 60.4 <0.1 36.3 2.4 1.73 78.8 <0.1 19.4
Androstenedione 2.3 29 4.1 7.85 2.82 1.37 88.0 5.4 7.54 6.63 1.37 84.5
Androsterone 1.1 14 2.0 4.22 0.73 0.52 94.5 1.5 4.18 1.77 0.54 93.5
Corticosterone 0.18 2.2 12 3.39 0.09 77.5 19.0 7.0 3.28 0.22 78.1 18.4
Cortisol 0.13 1.6 400 3.91 0.08 89.5 6.57 400 3.77 0.18 89.7 6.33
Cortisone 0.22 2.7 72 16.2 0.54 38.0 45.3 54 15.8 1.30 38.6 44.3
Dehydroepiandrosterone 5.3 66 24 4.13 3.38 <0.1 92.4 17 3.93 7.88 <0.1 88.1
11-Deoxycorticosterone 1.9 24 0.20 2.69 0.80 36.4 60.1 0.12 2.62 1.91 36.9 58.6
11-Deoxycortisol 1.3 16 1.4 3.37 0.67 77.1 18.9 0.60 3.24 1.57 77.1 18.1
Dihydrotestosterone 220 5500 1.7 0.88 59.7 0.22 39.2 0.65 0.47 78.4 0.12 21.0
Estradiol 49 680 0.084 2.32 19.6 <0.1 78.0 0.29 1.81 37.3 <0.1 60.8
Estriol 0.35 4.3 0.037 8.15 0.44 <0.2 91.3 0.10 8.10 1.06 <0.2 90.7
Estrone 12 150 0.081 3.96 7.37 <0.1 88.6 0.23 3.58 16.3 <0.1 80.1
Etiocholanolone 0.11 1.4 1.3 8.15 0.14 0.44 91.3 1.2 8.13 0.35 0.46 91.1
Pregnenolone 1.1 14 2.4 2.87 0.50 0.16 96.5 2.2 2.85 1.21 0.16 95.8
17α-Hydroxypregnenolone 0.19 2.3 5.4 4.27 0.12 <0.1 95.5 3.5 4.26 0.30 <0.1 95.4
Progesterone 0.71 8.8 0.57 2.39 0.26 17.2 80.1 0.65 2.36 0.63 17.7 79.3
17α-Hydroxyprogesterone 0.8 9.9 5.4 2.50 0.31 41.3 55.9 1.8 2.44 0.73 42.1 54.7
Testosterone 100 1600 23 2.23 44.3 3.56 49.9 1.3 1.36 66.0 2.26 30.4
In men, the concentrations of SHBG, CBG, and albumin were 28 nM, 0.7 μM, and 0.56 mM, respectively. In women, the concentrations of SHBG, CBG, and albumin were 37 nM, 0.7 μM, and 0.56 mM, respectively.

Synonyms

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SHBG has been known under a variety of different names including:[52][53][54]

  • Sex hormone-binding globulin (SHBG)
  • Sex steroid-binding globulin (SSBG, SBG)
  • Sex steroid-binding protein (SBP, SSBP)
  • Androgen-binding protein (ABP)
  • Estradiol-binding-protein (EBP)
  • Testosterone–estradiol binding globulin (TeBG, TEBG)

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000129214Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000005202Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Bardin CW, Musto N, Gunsalus G, Kotite N, Cheng SL, Larrea F, Becker R (1981). "Extracellular androgen binding proteins". Annual Review of Physiology. 43: 189–98. doi:10.1146/annurev.ph.43.030181.001201. PMID 7011179.
  6. ^ a b Hansson V, Weddington SC, French FS, McLean W, Smith A, Nayfeh SN, Ritzén EM, Hagenäs L (September 1976). "Secretion and role of androgen-binding proteins in the testis and epididymis". Journal of Reproduction and Fertility. Supplement (24 suppl): 17–33. PMID 1069850.
  7. ^ a b c d e f g h i j k l Hammond GL (September 2011). "Diverse roles for sex hormone-binding globulin in reproduction". Biology of Reproduction. 85 (3): 431–41. doi:10.1095/biolreprod.111.092593. PMC 4480437. PMID 21613632.
  8. ^ a b Somboonporn W, Davis SR (June 2004). "Testosterone effects on the breast: implications for testosterone therapy for women". Endocrine Reviews. 25 (3): 374–88. doi:10.1210/er.2003-0016. PMID 15180949.
  9. ^ a b c d e f g h i j Hammond GL (25 April 2017). "Sex Hormone-Binding Globulin and the Metabolic Syndrome". In Winters SJ, Huhtaniemi IT (eds.). Male Hypogonadism: Basic, Clinical and Therapeutic Principles. Humana Press. pp. 305–324. doi:10.1007/978-3-319-53298-1_15. ISBN 978-3-319-53298-1.
  10. ^ Becker K, Bilezikian JP, Bremner WJ, Hung W, Kahn CR (24 April 2001). Principles and Practice of Endocrinology and Metabolism. Lippincott Williams & Wilkins. ISBN 978-0-7817-1750-2. Retrieved 4 August 2012.
  11. ^ Quirk Jr G, Wendel Jr GD (6 December 2012). "Biologic Effects of Natural and Synthetic Estrogens". In Buchsbaum HJ (ed.). The Menopause. Springer Science & Business Media. pp. 62–. ISBN 978-1-4612-5525-3.
  12. ^ Fritz MA, Speroff L (28 March 2012). Clinical Gynecologic Endocrinology and Infertility. Lippincott Williams & Wilkins. pp. 44–. ISBN 978-1-4511-4847-3.
  13. ^ Hogeveen KN, Cousin P, Pugeat M, Dewailly D, Soudan B, Hammond GL (April 2002). "Human sex hormone-binding globulin variants associated with hyperandrogenism and ovarian dysfunction". J. Clin. Invest. 109 (7): 973–81. doi:10.1172/JCI14060. PMC 150924. PMID 11927624.
  14. ^ a b c Hammond GL, Bocchinfuso WP (1996). "Sex hormone-binding globulin: gene organization and structure/function analyses". Hormone Research. 45 (3–5): 197–201. doi:10.1159/000184787. PMID 8964583.
  15. ^ * Bérubé D, Séralini GE, Gagné R, Hammond GL (1991). "Localization of the human sex hormone-binding globulin gene (SHBG) to the short arm of chromosome 17 (17p12----p13)". Cytogenetics and Cell Genetics. 54 (1–2): 65–7. doi:10.1159/000132958. PMID 2249477.
  16. ^ Joseph DR (January 1998). "The rat androgen-binding protein (ABP/SHBG) gene contains triplet repeats similar to unstable triplets: evidence that the ABP/SHBG and the fragile X-related 2 genes overlap". Steroids. 63 (1): 2–4. doi:10.1016/S0039-128X(97)00087-1. PMID 9437788. S2CID 12825993.
  17. ^ Nakhla AM, Hryb DJ, Rosner W, Romas NA, Xiang Z, Kahn SM (May 2009). "Human sex hormone-binding globulin gene expression- multiple promoters and complex alternative splicing". BMC Molecular Biology. 10 (1): 37. doi:10.1186/1471-2199-10-37. PMC 2694190. PMID 19416531.
  18. ^ Piotrowski P, Gasik R, Lianeri M, Cieślak D, Wudarski M, Hrycaj P, Łacki JK, Jagodziński PP (January 2010). "Asp327Asn polymorphism of sex hormone-binding globulin gene is associated with systemic lupus erythematosus incidence". Molecular Biology Reports. 37 (1): 235–9. doi:10.1007/s11033-009-9639-7. PMID 19649728. S2CID 38541900.
  19. ^ Svartberg J, Schirmer H, Wilsgaard T, Mathiesen EB, Njølstad I, Løchen ML, Jorde R (March 2014). "Single-nucleotide polymorphism, rs1799941 in the Sex Hormone-Binding Globulin (SHBG) gene, related to both serum testosterone and SHBG levels and the risk of myocardial infarction, type 2 diabetes, cancer and mortality in men: the Tromsø Study". Andrology. 2 (2): 212–8. doi:10.1111/j.2047-2927.2013.00174.x. PMID 24327369. S2CID 206007163.
  20. ^ Thompson DJ, Healey CS, Baynes C, Kalmyrzaev B, Ahmed S, Dowsett M, Folkerd E, Luben RN, Cox D, Ballinger D, Pharoah PD, Ponder BA, Dunning AM, Easton DF (December 2008). "Identification of common variants in the SHBG gene affecting sex hormone-binding globulin levels and breast cancer risk in postmenopausal women". Cancer Epidemiology, Biomarkers & Prevention. 17 (12): 3490–8. doi:10.1158/1055-9965.EPI-08-0734. PMC 2660245. PMID 19064566.
  21. ^ a b Hammond GL, Underhill DA, Smith CL, Goping IS, Harley MJ, Musto NA, Cheng CY, Bardin CW (May 1987). "The cDNA-deduced primary structure of human sex hormone-binding globulin and location of its steroid-binding domain". FEBS Letters. 215 (1): 100–4. Bibcode:1987FEBSL.215..100H. doi:10.1016/0014-5793(87)80121-7. PMID 3569533. S2CID 23058156.
  22. ^ Selva DM, Hammond GL (July 2009). "Thyroid hormones act indirectly to increase sex hormone-binding globulin production by liver via hepatocyte nuclear factor-4alpha". Journal of Molecular Endocrinology. 43 (1): 19–27. doi:10.1677/JME-09-0025. PMID 19336534.
  23. ^ Selva DM, Hogeveen KN, Innis SM, Hammond GL (December 2007). "Monosaccharide-induced lipogenesis regulates the human hepatic sex hormone-binding globulin gene". The Journal of Clinical Investigation. 117 (12): 3979–87. doi:10.1172/JCI32249. PMC 2066187. PMID 17992261.
  24. ^ Simó R, Barbosa-Desongles A, Hernandez C, Selva DM (November 2012). "IL1β down-regulation of sex hormone-binding globulin production by decreasing HNF-4α via MEK-1/2 and JNK MAPK pathways". Molecular Endocrinology. 26 (11): 1917–27. doi:10.1210/me.2012-1152. PMC 5416961. PMID 22902540.
  25. ^ Simó R, Barbosa-Desongles A, Lecube A, Hernandez C, Selva DM (February 2012). "Potential role of tumor necrosis factor-α in downregulating sex hormone-binding globulin". Diabetes. 61 (2): 372–82. doi:10.2337/db11-0727. PMC 3266423. PMID 22210320.
  26. ^ Goto A, Morita A, Goto M, Sasaki S, Miyachi M, Aiba N, Terauchi Y, Noda M, Watanabe S (October 2012). "Associations of sex hormone-binding globulin and testosterone with diabetes among men and women (the Saku Diabetes study): a case control study". Cardiovascular Diabetology. 11: 130. doi:10.1186/1475-2840-11-130. PMC 3537568. PMID 23066943.
  27. ^ Unit Code 91215 Archived 2011-07-20 at the Wayback Machine at Mayo Clinic Medical Laboratories. Retrieved April 2011
  28. ^ [1]Becker DM (2019-07-27). "10 Simple Ways To Lower SHBG (#9 Is Fake News!)".
  29. ^ Kerlan V, Nahoul K, Le Martelot MT, Bercovici JP (February 1994). "Longitudinal study of maternal plasma bioavailable testosterone and androstanediol glucuronide levels during pregnancy". Clin. Endocrinol. (Oxf). 40 (2): 263–7. doi:10.1111/j.1365-2265.1994.tb02478.x. PMID 8137527. S2CID 40738152.
  30. ^ a b c d O'Leary P, Boyne P, Flett P, Beilby J, James I (1991). "Longitudinal assessment of changes in reproductive hormones during normal pregnancy". Clin Chem. 37 (5): 667–72. doi:10.1093/clinchem/37.5.667. PMID 1827758.
  31. ^ Mean F, Pellaton M, Magrini G (October 1977). "Study on the binding of dihydrotestosterone, testosterone and oestradiol with sex hormone binding globulin". Clin. Chim. Acta. 80 (1): 171–80. doi:10.1016/0009-8981(77)90276-5. PMID 561671.
  32. ^ Ruokonen A, Alén M, Bolton N, Vihko R (July 1985). "Response of serum testosterone and its precursor steroids, SHBG and CBG to anabolic steroid and testosterone self-administration in man". Journal of Steroid Biochemistry. 23 (1): 33–8. doi:10.1016/0022-4731(85)90257-2. PMID 3160892.
  33. ^ Ding EL, Song Y, Manson JE, Hunter DJ, Lee CC, Rifai N, Buring JE, Gaziano JM, Liu S (September 2009). "Sex hormone-binding globulin and risk of type 2 diabetes in women and men". The New England Journal of Medicine. 361 (12): 1152–63. doi:10.1056/NEJMoa0804381. PMC 2774225. PMID 19657112.
  34. ^ Cangemi R, Friedmann AJ, Holloszy JO, Fontana L (April 2010). "Long-term effects of calorie restriction on serum sex-hormone concentrations in men". Aging Cell. 9 (2): 236–42. doi:10.1111/j.1474-9726.2010.00553.x. PMC 3569090. PMID 20096034.
  35. ^ Manni A, Pardridge WM, Cefalu W, Nisula BC, Bardin CW, Santner SJ, Santen RJ (October 1985). "Bioavailability of albumin-bound testosterone". The Journal of Clinical Endocrinology and Metabolism. 61 (4): 705–10. doi:10.1210/jcem-61-4-705. PMID 4040924.
  36. ^ Le TN, Nestler JE, Strauss JF, Wickham EP (January 2012). "Sex hormone-binding globulin and type 2 diabetes mellitus". Trends in Endocrinology and Metabolism. 23 (1): 32–40. doi:10.1016/j.tem.2011.09.005. PMC 3351377. PMID 22047952.
  37. ^ Rosner W, Hryb DJ, Kahn SM, Nakhla AM, Romas NA (March 2010). "Interactions of sex hormone-binding globulin with target cells". Molecular and Cellular Endocrinology. 316 (1): 79–85. doi:10.1016/j.mce.2009.08.009. PMID 19698759. S2CID 27912941.
  38. ^ Tchaikovski SN, Rosing J (July 2010). "Mechanisms of estrogen-induced venous thromboembolism". Thromb Res. 126 (1): 5–11. doi:10.1016/j.thromres.2010.01.045. PMID 20163835.
  39. ^ Odlind V, Milsom I, Persson I, Victor A (June 2002). "Can changes in sex hormone binding globulin predict the risk of venous thromboembolism with combined oral contraceptive pills?". Acta Obstet Gynecol Scand. 81 (6): 482–90. PMID 12047300.
  40. ^ Morimont L, Haguet H, Dogné JM, Gaspard U, Douxfils J (2021). "Combined Oral Contraceptives and Venous Thromboembolism: Review and Perspective to Mitigate the Risk". Front Endocrinol (Lausanne). 12: 769187. doi:10.3389/fendo.2021.769187. PMC 8697849. PMID 34956081.
  41. ^ a b IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, World Health Organization, International Agency for Research on Cancer (2007). Combined Estrogen-progestogen Contraceptives and Combined Estrogen-progestogen Menopausal Therapy. World Health Organization. p. 157. ISBN 978-92-832-1291-1.
  42. ^ a b c Pugeat MM, Dunn JF, Nisula BC (July 1981). "Transport of steroid hormones: interaction of 70 drugs with testosterone-binding globulin and corticosteroid-binding globulin in human plasma". J. Clin. Endocrinol. Metab. 53 (1): 69–75. doi:10.1210/jcem-53-1-69. PMID 7195405.
  43. ^ a b Saartok T, Dahlberg E, Gustafsson JA (1984). "Relative binding affinity of anabolic-androgenic steroids: comparison of the binding to the androgen receptors in skeletal muscle and in prostate, as well as to sex hormone-binding globulin". Endocrinology. 114 (6): 2100–6. doi:10.1210/endo-114-6-2100. PMID 6539197.
  44. ^ a b c Kuhl H (2005). "Pharmacology of estrogens and progestogens: influence of different routes of administration" (PDF). Climacteric. 8 (Suppl 1): 3–63. doi:10.1080/13697130500148875. PMID 16112947. S2CID 24616324.
  45. ^ Pugeat MM, Dunn JF, Rodbard D, Nisula BC (December 1981). "The significance of drug interactions with human TeBG and CBG under physiological conditions: a new approach". J. Steroid Biochem. 15: 487–90. doi:10.1016/0022-4731(81)90319-8. PMID 7200170.
  46. ^ Machek SB, Cardaci TD, Wilburn DT, Willoughby DS (December 2020). "Considerations, possible contraindications, and potential mechanisms for deleterious effect in recreational and athletic use of selective androgen receptor modulators (SARMs) in lieu of anabolic androgenic steroids: A narrative review". Steroids. 164: 108753. doi:10.1016/j.steroids.2020.108753. PMID 33148520. S2CID 225049089.
  47. ^ Bergink EW, Loonen PB, Kloosterboer HJ (August 1985). "Receptor binding of allylestrenol, a progestagen of the 19-nortestosterone series without androgenic properties". Journal of Steroid Biochemistry. 23 (2): 165–8. doi:10.1016/0022-4731(85)90232-8. PMID 3928974.
  48. ^ Cunningham GR, Tindall DJ, Lobl TJ, Campbell JA, Means AR (September 1981). "Steroid structural requirements for high affinity binding to human sex steroid binding protein (SBP)". Steroids. 38 (3): 243–62. doi:10.1016/0039-128X(81)90061-1. PMID 7197818. S2CID 2702353.
  49. ^ Ojasoo T, Raynaud JP (November 1978). "Unique steroid congeners for receptor studies". Cancer Res. 38 (11 Pt 2): 4186–98. PMID 359134.
  50. ^ Lemke TL, Williams DA (2008). Foye's Principles of Medicinal Chemistry. Lippincott Williams & Wilkins. pp. 1306–. ISBN 978-0-7817-6879-5.
  51. ^ Dunn JF, Nisula BC, Rodbard D (July 1981). "Transport of steroid hormones: binding of 21 endogenous steroids to both testosterone-binding globulin and corticosteroid-binding globulin in human plasma". J. Clin. Endocrinol. Metab. 53 (1): 58–68. doi:10.1210/jcem-53-1-58. PMID 7195404.
  52. ^ "SHBG". GeneCards.
  53. ^ "Sex Steroid-Binding Protein". Steroid-Protein Interactions II. Springer Science & Business Media. 6 December 2012. p. 198. ISBN 978-3-642-82486-9.
  54. ^ Litwack G, Westphal U, eds. (12 December 1994). "Structure, Function, and Regulation of Androgen-Binding Protein?Sex Hormone-Binding Globulin". Vitamins and Hormones: Steroids. Academic Press. p. 200. ISBN 978-0-08-086646-8.

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