| 1. |
- Hu, Min, et al.
(författare)
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Hyperandrogenism and insulin resistance induce gravid uterine defects in association with mitochondrial dysfunction and aberrant ROS production.
- 2019
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Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 1522-1555 .- 0193-1849. ; 316:5
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Tidskriftsartikel (refereegranskat)abstract
- Women with polycystic ovary syndrome (PCOS) are at increased risk of miscarriage, which often accompanies the hyperandrogenism and insulin resistance seen in these patients. However, neither the combinatorial interaction between these two PCOS-related etiological factors nor the mechanisms of their actions in the uterus during pregnancy are well understood. We hypothesised that hyperandrogensim and insulin resistance exert a causative role in miscarriage by inducing defects in uterine function that are accompanied by mitochondrial-mediated oxidative stress, inflammation and perturbed gene expression. Here we tested this hypothesis by studying the metabolic, endocrine and uterine abnormalities in pregnant rats after exposure to daily injection of 5α-dihydrotestosterone (DHT, 1.66 mg/kg body weight/day) and/or insulin (6.0 IU/day) from gestational day 7.5 to 13.5. We showed that while DHT-exposed and insulin-exposed pregnant rats presented impaired insulin sensitivity, DHT+insulin-exposed pregnant rats exhibited hyperandrogenism and peripheral insulin resistance, which mirrors pregnant PCOS patients. Compared to controls, hyperandrogenism and insulin resistance in the dam was associated with alterations in uterine morphology and aberrant expression of genes responsible for decidualization, placentation, angiogenesis and insulin signaling. Moreover, we observed changes in uterine mitochondrial function and homeostasis and suppression of both oxidative and antioxidative defenses in response to the hyperandrogenism and insulin resistance. These findings demonstrate that hyperandrogenism and insulin resistance induce mitochondria-mediated damage and a resulting imbalance between oxidative and antioxidative stress responses in the gravid uterus.
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| 2. |
- Hu, Min, et al.
(författare)
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Perturbed ovarian and uterine glucocorticoid receptor signaling accompanies the balanced regulation of mitochondrial function and NFκB-mediated inflammation under conditions of hyperandrogenism and insulin resistance.
- 2019
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Ingår i: Life sciences. - : Elsevier BV. - 1879-0631 .- 0024-3205. ; 232
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to determine whether glucocorticoid receptor (GR) signaling, mitochondrial function, and local inflammation in the ovary and uterus are intrinsically different in rats with hyperandrogenism and insulin resistance compared to controls.Female Sprague Dawley rats were exposed to daily injections of human chorionic gonadotropin and/or insulin.In both the ovary and the uterus, decreased expression of the two GR isoforms was concurrent with increased expression of Fkbp51 but not Fkbp52 mRNA in hCG+insulin-treated rats. However, these rats exhibited contrasting regulation of Hsd11b1 and Hsd11b2 mRNAs in the two tissues. Further, the expression of several oxidative phosphorylation-related proteins decreased in the ovary and uterus following hCG and insulin stimulation, in contrast to increased expression of many genes involved in mitochondrial function and homeostasis. Additionally, hCG+insulin-treated rats showed increased expression of ovarian and uterine NFκB signaling proteins and Tnfaip3 mRNA. The mRNA expression of Il1b, Il6, and Mmp2 was decreased in both tissues, while the mRNA expression of Tnfa, Ccl2, Ccl5, and Mmp3 was increased in the uterus. Ovaries and uteri from animals co-treated with hCG and insulin showed increased collagen deposition compared to controls.Our observations suggest that hyperandrogenism and insulin resistance disrupt ovarian and uterine GR activation and trigger compensatory or adaptive effects for mitochondrial homeostasis, allowing tissue-level maintenance of mitochondrial function in order to limit ovarian and uterine dysfunction. Our study also suggests that hyperandrogenism and insulin resistance activate NFκB signaling resulting in aberrant regulation of inflammation-related gene expression.
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| 3. |
- Hu, Min, et al.
(författare)
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Uterine progesterone signaling is a target for metformin therapy in PCOS-like rats.
- 2018
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 237:2, s. 123-137
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Tidskriftsartikel (refereegranskat)abstract
- Impaired progesterone (P4) signaling is linked to endometrial dysfunction and infertility in women with polycystic ovary syndrome (PCOS). Here, we report for the first time that elevated expression of progesterone receptor (PGR) isoforms A and B parallels increased estrogen receptor (ER) expression in PCOS-like rat uteri. The aberrant PGR-targeted gene expression in PCOS-like rats before and after implantation overlaps with dysregulated expression of Fkbp52 and Ncoa2, two genes that contribute to the development of uterine P4 resistance. In vivo and in vitro studies of the effects of metformin on the regulation of the uterine P4 signaling pathway under PCOS conditions showed that metformin directly inhibits the expression of PGR and ER along with the regulation of several genes that are targeted dependently or independently of PGR-mediated uterine implantation. Functionally, metformin treatment corrected the abnormal expression of cell-specific PGR and ER and some PGR-target genes in PCOS-like rats with implantation. Additionally, we documented how metformin contributes to the regulation of the PGR-associated MAPK/ERK/p38 signaling pathway in the PCOS-like rat uterus. Our data provide novel insights into how metformin therapy regulates uterine P4 signaling molecules under PCOS conditions.
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| 4. |
- Zhang, Yuehui, et al.
(författare)
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Hyperandrogenism and insulin resistance-induced fetal loss : evidence for placental mitochondrial abnormalities and elevated reactive oxygen species production in pregnant rats that mimic the clinical features of polycystic ovary syndrome
- 2019
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Ingår i: Journal of Physiology. - : WILEY. - 0022-3751 .- 1469-7793. ; 597:15, s. 3927-3950
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Tidskriftsartikel (refereegranskat)abstract
- Women with polycystic ovary syndrome (PCOS) commonly suffer from miscarriage, but the underlying mechanisms remain unknown. Herein, pregnant rats chronically treated with 5 alpha-dihydrotestosterone (DHT) and insulin exhibited hyperandrogenism and insulin resistance, as well as increased fetal loss, and these features are strikingly similar to those observed in pregnant PCOS patients. Fetal loss in our DHT+insulin-treated pregnant rats was associated with mitochondrial dysfunction, disturbed superoxide dismutase 1 and Keap1/Nrf2 antioxidant responses, over-production of reactive oxygen species (ROS) and impaired formation of the placenta. Chronic treatment of pregnant rats with DHT or insulin alone indicated that DHT triggered many of the molecular pathways leading to placental abnormalities and fetal loss, whereas insulin often exerted distinct effects on placental gene expression compared to co-treatment with DHT and insulin. Treatment of DHT+insulin-treated pregnant rats with the antioxidant N-acetylcysteine improved fetal survival but was deleterious in normal pregnant rats. Our results provide insight into the fetal loss associated with hyperandrogenism and insulin resistance in women and suggest that physiological levels of ROS are required for normal placental formation and fetal survival during pregnancy. Women with polycystic ovary syndrome (PCOS) commonly suffer from miscarriage, but the underlying mechanism of PCOS-induced fetal loss during pregnancy remains obscure and specific therapies are lacking. We used pregnant rats treated with 5 alpha-dihydrotestosterone (DHT) and insulin to investigate the impact of hyperandrogenism and insulin resistance on fetal survival and to determine the molecular link between PCOS conditions and placental dysfunction during pregnancy. Our study shows that pregnant rats chronically treated with a combination of DHT and insulin exhibited endocrine aberrations such as hyperandrogenism and insulin resistance that are strikingly similar to those in pregnant PCOS patients. Of pathophysiological significance, DHT+insulin-treated pregnant rats had greater fetal loss and subsequently decreased litter sizes compared to normal pregnant rats. This negative effect was accompanied by impaired trophoblast differentiation, increased glycogen accumulation, and decreased angiogenesis in the placenta. Mechanistically, we report that over-production of reactive oxygen species (ROS) in the placenta, mitochondrial dysfunction, and disturbed superoxide dismutase 1 (SOD1) and Keap1/Nrf2 antioxidant responses constitute important contributors to fetal loss in DHT+insulin-treated pregnant rats. Many of the molecular pathways leading to placental abnormalities and fetal loss in DHT+insulin treatment were also seen in pregnant rats treated with DHT alone, whereas pregnant rats treated with insulin alone often exerted distinct effects on placental gene expression compared to insulin treatment in combination with DHT. We also found that treatment with the antioxidant N-acetylcysteine (NAC) improved fetal survival in DHT+insulin-treated pregnant rats, an effect related to changes in Keap1/Nrf2 and nuclear factor-kappa B signalling. However, NAC administration resulted in fetal loss in normal pregnant rats, most likely due to PCOS-like endocrine abnormality induced by the treatment. Our results suggest that the deleterious effects of hyperandrogenism and insulin resistance on fetal survival are related to a constellation of mitochondria-ROS-SOD1/Nrf2 changes in the placenta. Our findings also suggest that physiological levels of ROS are required for normal placental formation and fetal survival during pregnancy.
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| 5. |
- Zhang, Yuehui, et al.
(författare)
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Hyperandrogenism and insulin resistance-induced fetal loss: evidence for placental mitochondrial abnormalities and elevated ROS production in pregnant rats that mimic the clinical features of PCOS. : PCOS-induced fetal loss is linked to placental defects
- 2019
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Ingår i: The Journal of physiology. - 1469-7793. ; 597:15, s. 3927-3950
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Tidskriftsartikel (refereegranskat)abstract
- Women with polycystic ovary syndrome (PCOS) commonly suffer from miscarriage, but the underlying mechanisms remain unknown. Herein, pregnant rats chronically treated with 5α-dihydrotestosterone (DHT) and insulin exhibited hyperandrogenism and insulin resistance, as well as increased fetal loss, and these features are strikingly similar to those observed in pregnant PCOS patients. Fetal loss in our DHT+insulin-treated pregnant rats was associated with mitochondrial dysfunction, disturbed SOD1 and Keap1/Nrf2 antioxidant responses, over-production of reactive oxygen species (ROS), and impaired formation of the placenta. Chronic treatment of pregnant rats with DHT or insulin alone indicated that DHT triggered many of the molecular pathways leading to placental abnormalities and fetal loss, whereas insulin often exerted distinct effects on placental gene expression compared to co-treatment with DHT and insulin. Treatment of DHT+insulin-treated pregnant rats with the antioxidant N-acetylcysteine improved fetal survival but was deleterious in normal pregnant rats. Our results provide insight into the fetal loss associated with hyperandrogenism and insulin resistance in women and suggest that physiological levels of ROS are required for normal placental formation and fetal survival during pregnancy.Women with polycystic ovary syndrome (PCOS) commonly suffer from miscarriage, but the underlying mechanism of PCOS-induced fetal loss during pregnancy remains obscure and specific therapies are lacking. We used pregnant rats treated with 5α-dihydrotestosterone (DHT) and insulin to investigate the impact of hyperandrogenism and insulin resistance on fetal survival and to determine the molecular link between PCOS conditions and placental dysfunction during pregnancy. Our study shows that pregnant rats chronically treated with a combination of DHT and insulin exhibited endocrine aberrations such as hyperandrogenism and insulin resistance that are strikingly similar to those in pregnant PCOS patients. Of pathophysiological significance, DHT+insulin-treated pregnant rats had greater fetal loss and subsequently decreased litter sizes compared to normal pregnant rats. This negative effect was accompanied by impaired trophoblast differentiation, increased glycogen accumulation, and decreased angiogenesis in the placenta. Mechanistically, we report that over-production of reactive oxygen species (ROS) in the placenta, mitochondrial dysfunction, and disturbed SOD1 and Keap1/Nrf2 antioxidant responses constitute important contributors to fetal loss in DHT+insulin-treated pregnant rats. Many of the molecular pathways leading to placental abnormalities and fetal loss in DHT+insulin treatment were also seen in pregnant rats treated with DHT alone, whereas pregnant rats treated with insulin alone often exerted distinct effects on placental gene expression compared to insulin treatment in combination with DHT. We also found that treatment with the antioxidant N-acetylcysteine (NAC) improved fetal survival in DHT+insulin-treated pregnant rats, an effect related to changes in Keap1/Nrf2 and NFκB signaling. However, NAC administration resulted in fetal loss in normal pregnant rats, most likely due to PCOS-like endocrine abnormality induced by the treatment. Our results suggest that the deleterious effects of hyperandrogenism and insulin resistance on fetal survival are related to a constellation of mitochondrial-ROS-SOD1/Nrf2 changes in the placenta. Our findings also suggest that physiological levels of ROS are required for normal placental formation and fetal survival during pregnancy. This article is protected by copyright. All rights reserved.
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