| 1. |
- Nilsson, Maria E., et al.
(författare)
-
Measurement of a comprehensive sex steroid profile in rodent serum by high-sensitive gas chromatography-tandem mass spectrometry.
- 2015
-
Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 156:7, s. 2492-502
-
Tidskriftsartikel (refereegranskat)abstract
- Accurate measurement of sex steroid concentrations in rodent serum is essential to evaluate mouse and rat models for sex steroid-related disorders. The aim of the present study was to develop a sensitive and specific gas chromatography-tandem mass spectrometry (GC-MS/MS) method to assess a comprehensive sex steroid profile in rodent serum. A major effort was invested in reaching an exceptionally high sensitivity for measuring serum estradiol concentrations. We established a GC-MS/MS assay with a lower limit of detection for estradiol, estrone, testosterone, dihydrotestosterone, progesterone, androstenedione and dehydroepiandrosterone of 0.3, 0.5, 4, 1.6, 8, 4 and 50 pg/ml, respectively, while the corresponding values for the lower limit of quantification were 0.5, 0.5, 8, 2.5, 74, 12 and 400 pg/ml, respectively. Calibration curves were linear, intra- and inter-assay CVs were low and accuracy was excellent for all analytes. The established assay was used to accurately measure a comprehensive sex steroid profile in female rats and mice according to estrus cycle phase. In addition, we characterized the impact of age, sex, gonadectomy, and estradiol treatment on serum concentrations of these sex hormones in mice. In conclusion, we have established a highly sensitive and specific GC-MS/MS method to assess a comprehensive sex steroid profile in rodent serum in a single run. This GC-MS/MS assay has, to the best of our knowledge, the best detectability reported for estradiol. Our method therefore represents an ideal tool to characterize sex steroid metabolism in a variety of sex steroid-related rodent models and in human samples with low estradiol levels.
|
|
| 2. |
- Benrick, Anna, 1979, et al.
(författare)
-
Adiponectin protects against development of metabolic disturbances in a PCOS mouse model
- 2017
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:34, s. E7187-E7196
-
Tidskriftsartikel (refereegranskat)abstract
- Adiponectin, together with adipocyte size, is the strongest factor associated with insulin resistance in women with polycystic ovary syndrome (PCOS). This study investigates the causal relationship between adiponectin levels and metabolic and reproductive functions in PCOS. Prepubertal mice overexpressing adiponectin from adipose tissue (APNtg), adiponectin knockouts (APNko), and their wild-type (WT) littermate mice were continuously exposed to placebo or dihydrotestosterone (DHT) to induce PCOS-like traits. As expected, DHT exposure led to reproductive dysfunction, as judged by continuous anestrus, smaller ovaries with a decreased number of corpus luteum, and an increased number of cystic/atretic follicles. A two-way between-groups analysis showed that there was a significant main effect for DHT exposure, but not for genotype, indicating adiponectin does not influence follicle development. Adiponectin had, however, some protective effects on ovarian function. Similar to in many women with PCOS, DHT exposure led to reduced adiponectin levels, larger adipocyte size, and reduced insulin sensitivity in WTs. APNtg mice remained metabolically healthy despite DHT exposure, while APNko-DHT mice were even more insulin resistant than their DHT-exposed littermate WTs. DHT exposure also reduced the mRNA expression of genes involved in metabolic pathways in gonadal adipose tissue of WT and APNko, but this effect of DHT was not observed in APNtg mice. Moreover, APNtg-DHT mice displayed increased pancreatic mRNA levels of insulin receptors, Pdx1 and Igf1R, suggesting adiponectin stimulates beta cell viability/hyperplasia in the context of PCOS. In conclusion, adiponectin improves metabolic health but has only minor effects on reproductive functions in this PCOS-like mouse model.
|
|
| 3. |
- Benrick, Anna, 1979, et al.
(författare)
-
Enhanced insulin sensitivity and acute regulation of metabolic genes and signaling pathways after a single electrical or manual acupuncture session in female insulin-resistant rats.
- 2014
-
Ingår i: Acta Diabetologica. - 0940-5429 .- 1432-5233. ; 51:6, s. 963-972
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: To compare the effect of a single session of acupuncture with either low-frequency electrical or manual stimulation on insulin sensitivity and molecular pathways in the insulin-resistant dihydrotestosterone-induced rat polycystic ovary syndrome (PCOS) model. Both stimulations cause activation of afferent nerve fibers. In addition, electrical stimulation causes muscle contractions, enabling us to differentiate changes induced by activation of sensory afferents from contraction-induced changes. MATERIALS AND METHODS: Control and PCOS rats were divided into no-stimulation, manual-, and electrical stimulation groups and insulin sensitivity was measured by euglycemic hyperinsulinemic clamp. Manually stimulated needles were rotated 180° ten times every 5 min, or low-frequency electrical stimulation was applied to evoke muscle twitches for 45 min. Gene and protein expression were analyzed by real-time PCR and Western blot. RESULTS: The glucose infusion rate (GIR) was lower in PCOS rats than in controls. Electrical stimulation was superior to manual stimulation during treatment but both methods increased GIR to the same extent in the post-stimulation period. Electrical stimulation decreased mRNA expression of Adipor2, Adrb1, Fndc5, Erk2, and Tfam in soleus muscle and increased ovarian Adrb2 and Pdf. Manual stimulation decreased ovarian mRNA expression of Erk2 and Sdnd. Electrical stimulation increased phosphorylated ERK levels in soleus muscle. CONCLUSIONS: One acupuncture session with electrical stimulation improves insulin sensitivity and modulates skeletal muscle gene and protein expression more than manual stimulation. Although electrical stimulation is superior to manual in enhancing insulin sensitivity during stimulation, they are equally effective after stimulation indicating that it is activation of sensory afferents rather than muscle contraction per se leading to the observed changes.
|
|
| 4. |
- Benrick, Anna, 1979, et al.
(författare)
-
Resveratrol Is Not as Effective as Physical Exercise for Improving Reproductive and Metabolic Functions in Rats with Dihydrotestosterone-Induced Polycystic Ovary Syndrome
- 2013
-
Ingår i: Evidence-Based Complementary and Alternative Medicine. - : Hindawi Limited. - 1741-427X .- 1741-4288.
-
Tidskriftsartikel (refereegranskat)abstract
- Polycystic ovary syndrome (PCOS) is a reproductive and metabolic disorder associated with obesity and insulin resistance that often precedes the development of type-2 diabetes. Rats continuously exposed to dihydrotestosterone from prepuberty display typical reproductive and metabolic PCOS characteristics including anovulation, polycystic ovaries, insulin resistance, and obesity. Our aim was to investigate if resveratrol improves reproductive and metabolic functions in PCOS rats. The effect was compared to exercise. Control and PCOS rats were treated with vehicle or resveratrol (400 mg · kg−1 · day−1) for 5-6 weeks. Another group of PCOS rats received vehicle treatment and exercised for 5-6 weeks. Insulin sensitivity was determined by euglycemic-hyperinsulinemic clamp. The glucose infusion rate was lower in the PCOS-vehicle group compared to control-vehicle rats (). Exercise increased insulin sensitivity compared with PCOS-vehicle rats (), but resveratrol did not. Resveratrol treatment and exercise resulted in smaller adipocytes, upregulated estrogen-related receptor α gene expression in subcutaneous fat, and improved estrus cyclicity in the previously acyclic PCOS rats. Although resveratrol had positive effects on adiposity and cyclicity in a similar manner to exercise, resveratrol does not seem to be a good candidate for treating insulin resistance associated with PCOS because no improvement in insulin sensitivity was observed in PCOS rats on normal chow.
|
|
| 5. |
- Hu, Min, et al.
(författare)
-
Maternal testosterone exposure increases anxiety-like behavior and impacts the limbic system in the offspring.
- 2015
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 112:46, s. 14348-53
-
Tidskriftsartikel (refereegranskat)abstract
- During pregnancy, women with polycystic ovary syndrome (PCOS) display high circulating androgen levels that may affect the fetus and increase the risk of mood disorders in offspring. This study investigated whether maternal androgen excess causes anxiety-like behavior in offspring mimicking anxiety disorders in PCOS. The PCOS phenotype was induced in rats following prenatal androgen (PNA) exposure. PNA offspring displayed anxiety-like behavior in the elevated plus maze, which was reversed by flutamide [androgen receptor (AR) blocker] and tamoxifen [selective estrogen receptor (ER) modulator]. Circulating sex steroids did not differ between groups at adult age. The expression of serotonergic and GABAergic genes associated with emotional regulation in the amygdala was consistent with anxiety-like behavior in female, and partly in male PNA offspring. Furthermore, AR expression in amygdala was reduced in female PNA offspring and also in females exposed to testosterone in adult age. To determine whether AR activation in amygdala affects anxiety-like behavior, female rats were given testosterone microinjections into amygdala, which resulted in anxiety-like behavior. Together, these data describe the anxiety-like behavior in PNA offspring and adult females with androgen excess, an impact that seems to occur during fetal life, and is mediated via AR in amygdala, together with changes in ERα, serotonergic, and GABAergic genes in amygdala and hippocampus. The anxiety-like behavior following testosterone microinjections into amygdala demonstrates a key role for AR activation in this brain area. These results suggest that maternal androgen excess may underpin the risk of developing anxiety disorders in daughters and sons of PCOS mothers.
|
|
| 6. |
- Kokosar, Milana, et al.
(författare)
-
Epigenetic and Transcriptional Alterations in Human Adipose Tissue of Polycystic Ovary Syndrome
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic and epigenetic factors may predispose women to polycystic ovary syndrome (PCOS), a common heritable disorder of unclear etiology. Here we investigated differences in genome-wide gene expression and DNA methylation in adipose tissue from 64 women with PCOS and 30 controls. In total, 1720 unique genes were differentially expressed (Q < 0.05). Six out of twenty selected genes with largest expression difference (CYP1B1, GPT), genes linked to PCOS (RAB5B) or type 2 diabetes (PPARG, SVEP1), and methylation (DMAP1) were replicated in a separate case-control study. In total, 63,213 sites (P < 0.05) and 440 sites (Q < 0.15) were differently methylated. Thirty differentially expressed genes had corresponding changes in 33 different DNA methylation sites. Moreover, a total number of 1913 pairs of differentially expressed "gene-CpG" probes were significantly correlated after correction for multiple testing and corresponded with 349 unique genes. In conclusion, we identified a large number of genes and pathways that are affected in adipose tissue from women with PCOS. We also identified specific DNA methylation pathways that may affect mRNA expression. Together, these novel findings show that women with PCOS have multiple transcriptional and epigenetic changes in adipose tissue that are relevant for development of the disease.
|
|
| 7. |
- Maliqueo, Manuel, et al.
(författare)
-
Circulating gonadotropins and ovarian adiponectin system are modulated by acupuncture independently of sex steroid or beta-adrenergic action in a female hyperandrogenic rat model of polycystic ovary syndrome
- 2015
-
Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 0303-7207. ; 412:C, s. 159-169
-
Tidskriftsartikel (refereegranskat)abstract
- Acupuncture with combined manual and low-frequency electrical stimulation, or electroacupuncture (EA), reduces endocrine and reproductive dysfunction in women with polycystic ovary syndrome (PCOS), likely by modulating sympathetic nerve activity or sex steroid synthesis. To test this hypothesis, we induced PCOS in rats by prepubertal implantation of continuous-release letrozole pellets (200 mu g/day) or vehicle. Six weeks later, rats were treated for 5-6 weeks with low-frequency EA 5 days/week, subcutaneous injection of 17 beta-estradiol (2.0 mu g) every fourth day, or a beta-adrenergic blocker (propranolol hydrochloride, 0.1 mg/kg) 5 days/week. Letrozole controls were handled without needle insertion or injected with sesame oil every fourth day. Estrous cyclicity, ovarian morphology, sex steroids, gonadotropins, insulin-like growth factor I, bone mineral density, and gene and protein expression in ovarian tissue were measured. Low-frequency EA induced estrous-cycle changes, decreased high levels of circulating luteinizing hormone (LH) and the LH/follicle-stimulating hormone (FSH) ratio, decreased high ovarian gene expression of adiponectin receptor 2, and increased expression of adiponectin receptor 2 protein and phosphorylation of ERK1/2. EA also increased cortical bone mineral density. Propranolol decreased ovarian expression of Foxo3, Srd5al, and Hif1a. Estradiol decreased circulating LH, induced estrous cycle changes, and decreased ovarian expression of Adipor1, Foxo3, and Pik3r1. Further, total bone mineral density was higher in the letrozole-estradiol group. Thus, EA modulates the circulating gonadotropin levels independently of sex steroids or beta-adrenergic action and affects the expression of ovarian adiponectin system. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
|
|
| 8. |
- Maliqueo, Manuel, et al.
(författare)
-
Continuous Administration of a P450 Aromatase Inhibitor Induces Polycystic Ovary Syndrome with a Metabolic and Endocrine Phenotype in Female Rats at Adult Age
- 2013
-
Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 154:1, s. 434-445
-
Tidskriftsartikel (refereegranskat)abstract
- Studying the mechanisms for the complex pathogenesis of polycystic ovary syndrome (PCOS) requires animal models with endocrine, reproductive, and metabolic features of the syndrome. Hyperandrogenism seems to be a central factor in PCOS, leading to anovulation and insulin resistance. In female rats, continuous administration of letrozole, a nonsteroidal inhibitor of P450 aromatase, at 400 mu g/d starting before puberty induces hyperandrogenemia and reproductive abnormalities similar to those in women with PCOS. However, despite high circulating testosterone levels, these rats do not develop metabolic abnormalities, perhaps because of their supraphysiological testosterone concentrations or because estrogen synthesis is completely blocked in insulin-sensitive tissues. To test the hypothesis that continuous administration of lower doses of letrozole starting before puberty would result in both metabolic and reproductive phenotypes of PCOS, we performed a 12-wk dose-response study. At 21 d of age, 46 female Wistar rats were divided into two letrozole groups (100 or 200 mu g/d) and a control group (placebo). Both letrozole doses resulted in increased body weight, inguinal fat accumulation, anovulation, larger ovaries with follicular atresia and multiples cysts, endogenous hyperandrogemia, and lower estrogen levels. Moreover, rats that received 200 mu g/d had insulin resistance and enlarged adipocytes in inguinal and mesenteric fat depots, increased circulating levels of LH, decreased levels of FSH, and increased ovarian expression of Cyp17a1 mRNA. Thus, continuous administration of letrozole, 200 mu g/d, to female rats for 90 d starting before puberty results in a PCOS model with reproductive and metabolic features of the syndrome. (Endocrinology 154: 434-445, 2013)
|
|
| 9. |
- Maliqueo, Manuel, et al.
(författare)
-
Placental STAT3 signaling is activated in women with polycystic ovary syndrome
- 2015
-
Ingår i: Human reproduction (Oxford, England). - : Oxford University Press (OUP). - 0268-1161 .- 1460-2350. ; 30:3, s. 692-700
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY QUESTION: Does polycystic ovary syndrome (PCOS) in women without pregnancy complications affect placental signal transducer and activator of transcription 3 (STAT3) and mechanistic target of rapamycin (mTOR) signaling? SUMMARY ANSWER: Placental STAT3 signaling is activated but mTOR signaling is unaffected in PCOS. WHAT IS KNOWN ALREADY: Women with PCOS have increased risk of poor pregnancy outcomes (e.g. restricted or accelerated fetal growth), indicating placental dysfunction. Placental STAT3 and mTOR pathways regulate placental function and indirectly affect fetal growth. STUDY DESIGN, SIZE, DURATION: In a case-control study, placental tissue and maternal blood were collected at delivery from 40 control pregnant women and 38 PCOS women with uncomplicated pregnancy. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with PCOS were recruited at two medical centers and pregnant controls were recruited at one of these centers. Placental mRNA expression of genes encoding proteins related to steroid action, metabolic pathways and cytokines was analyzed by quantitative RT-PCR. Phosphorylated placental STAT3 (P-STAT3) and mTOR targets was measured by western blot. Levels of sex steroids in serum were determined by mass spectrometry. MAIN RESULTS AND THE ROLE OF CHANCE: Placental P-STAT3 (Tyr-705) was increased in women with PCOS (P < 0.05) versus controls. Placental mTOR signaling was not affected in PCOS women when compared with controls. Circulating levels of androstenedione, androst-5-ene-3beta, 17beta-diol, testosterone, 5alpha-dihydrotestosterone and etiocholanolone glucuronide were higher and estradiol lower in women with PCOS than in controls (all P < 0.05). No correlation between sex steroid levels in serum and P-STAT3 was observed. LIMITATIONS, REASONS FOR CAUTION: Women with PCOS and pregnancy complications were excluded to avoid the confounding effects of placental pathologies, which could modify STAT3 and mTOR signaling. Moreover, 97.4% of women with PCOS in the study displayed oligoamenorrhea at diagnosis. Thus, the current findings could be restricted to PCOS women with the oligo-anovulatory phenotype without pregnancy complications. WIDER IMPLICATIONS OF THE FINDINGS: Phosphorylation of STAT3 is increased in the placenta from women with PCOS and uncomplicated pregnancies, indicating that specific metabolic placental pathways are activated in the absence of obstetric and perinatal complications. STUDY FUNDING/COMPETING INTERESTS: The work was supported by the Swedish Medical Research Council (Project No. 2011-2732 and 2014-2775); Jane and Dan Olsson Foundation, Wilhelm and Martina Lundgrens's Science Fund; Hjalmar Svensson Foundation (E.S.-V and M.M.); Adlerbert Research Foundation; Swedish federal government under the LUA/ALF agreement ALFFGBG-136481 and 429501 and the Regional Research and Development agreement (VGFOUREG-5171, -11296 and -7861). MM thanks the Becas Chile Programme (Chile) and University of Chile for financial support through a postdoctoral fellowship. There are no competing interests.
|
|
| 10. |
- Maliqueo, Manuel, et al.
(författare)
-
Rodent Models of Polycystic Ovary Syndrome: Phenotypic Presentation, Pathophysiology, and the Effects of Different Interventions
- 2014
-
Ingår i: Seminars in Reproductive Medicine. - : Georg Thieme Verlag KG. - 1526-8004 .- 1526-4564. ; 32:3, s. 183-193
-
Tidskriftsartikel (refereegranskat)abstract
- This review focuses on rodent models exposed to sex steroids prepubertally and describes their phenotypes and pathophysiology with specific focus on the estradiol valerate-, dihydrotestosterone-, and letrozole-induced rat polycystic ovary syndrome (PCOS) models. Phenotypic presentations are compared among models as a function of the timing and dose of the exposure. Furthermore, the use of these models to study the possible effects and mechanisms of different treatment modalities relevant for women with PCOS will be discussed. Importantly, we do not claim to review all available rodent models of PCOS. Despite the variety of rodent PCOS models currently available, there is no "gold standard" that mimics the complete range of abnormalities observed in women with PCOS. In this regard, it is important to select the most suitable model for the pathophysiological experiment to be performed or the treatment strategy to be tested. Important variables to take into consideration are dose, route of administration, timing and duration of exposure, and the relevance of the abnormalities of the reproductive and metabolic axes in the rodent model to those observed in human PCOS.
|
|
