| 1. |
- Hu, Min, et al.
(författare)
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Defective uterine spiral artery remodelling and placental senescence in a pregnant rat model of polycystic ovary syndrome. : Impaired SpA remodelling in PCOS
- 2023
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Ingår i: The American journal of pathology. - 1525-2191. ; 193:12, s. 1916-1935
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Tidskriftsartikel (refereegranskat)abstract
- Pregnancy-related problems have been linked to impairments in maternal uterine spiral artery (SpA) remodelling. The mechanisms underlying this association are still unclear, as are whether hyperandrogenism and insulin resistance - the two common manifestations of polycystic ovary syndrome (PCOS) - affect uterine SpA remodelling. This study verified previous work in which exposure to 5-dihydrotestosterone (DHT) and insulin (INS) in rats during pregnancy resulted in hyperandrogenism, insulin intolerance, and higher foetal mortality. It also found that exposure to DHT and INS dysregulated the expression of angiogenesis-related genes in the uterus and placenta. It also decreased expression of endothelial nitric oxide synthase and matrix metallopeptidases 2 and 9, increased fibrotic collagen deposits in the uterus, and reduced expression of marker genes for SpA-associated trophoblast giant cells. These changes were related to a greater proportion of un-remodelled uterine SpAs and a smaller proportion of highly remodelled arteries in DHT+INS-exposed rats. Placentas from DHT+INS-exposed rats exhibited decreased basal and labyrinth zone regions, reduced maternal blood spaces, diminished labyrinth vascularity, and an imbalance in the abundance of vascular and smooth muscle proteins. Furthermore, placentas from DHT+INS-exposed rats showed expression of placental insufficiency markers and a significant increase in cell senescence-associated protein levels. Altogether, this work demonstrates increased pregnancy complications in PCOS may be mediated by problems with uterine SpA remodelling, placental functionality, and placental senescence.
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| 2. |
- Zhang, Yuehui, et al.
(författare)
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Increased uterine androgen receptor protein abundance results in implantation and mitochondrial defects in pregnant rats with hyperandrogenism and insulin resistance. : Deciphering the role of uterine AR in PCOS during early pregnancy
- 2021
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Ingår i: Journal of molecular medicine (Berlin, Germany). - : Springer Science and Business Media LLC. - 1432-1440 .- 0946-2716. ; 99, s. 1427-1446
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we show that during normal rat pregnancy, there is a gestational stage-dependent decrease in androgen receptor (AR) abundance in the gravid uterus and that this is correlated with the differential expression of endometrial receptivity and decidualization genes during early and mid-gestation. In contrast, exposure to 5α-dihydrotestosterone (DHT) and insulin (INS) or DHT alone significantly increased AR protein levels in the uterus in association with the aberrant expression of endometrial receptivity and decidualization genes, as well as disrupted implantation. Next, we assessed the functional relevance of the androgen-AR axis in the uterus for reproductive outcomes by treating normal pregnant rats and pregnant rats exposed to DHT and INS with the anti-androgen flutamide. We found that AR blockage using flutamide largely attenuated the DHT and INS-induced maternal endocrine, metabolic, and fertility impairments in pregnant rats in association with suppressed induction of uterine AR protein abundance and androgen-regulated response protein and normalized expression of several endometrial receptivity and decidualization genes. Further, blockade of AR normalized the expression of the mitochondrial biogenesis marker Nrf1 and the mitochondrial functional proteins Complexes I and II, VDAC, and PHB1. However, flutamide treatment did not rescue the compromised mitochondrial structure resulting from co-exposure to DHT and INS. These results demonstrate that functional AR protein is an important factor for gravid uterine function. Impairments in the uterine androgen-AR axis are accompanied by decreased endometrial receptivity, decidualization, and mitochondrial dysfunction, which might contribute to abnormal implantation in pregnant PCOS patients with compromised pregnancy outcomes and subfertility. KEY MESSAGES: The proper regulation of uterine androgen receptor (AR) contributes to a normal pregnancy process, whereas the aberrant regulation of uterine AR might be linked to polycystic ovary syndrome (PCOS)-induced pregnancy-related complications. In the current study, we found that during normal rat pregnancy there is a stage-dependent decrease in AR abundance in the gravid uterus and that this is correlated with the differential expression of the endometrial receptivity and decidualization genes Spp1, Prl, Igfbp1, and Hbegf. Pregnant rats exposed to 5α-dihydrotestosterone (DHT) and insulin (INS) or to DHT alone show elevated uterine AR protein abundance and implantation failure related to the aberrant expression of genes involved in endometrial receptivity and decidualization in early to mid-gestation. Treatment with the anti-androgen flutamide, starting from pre-implantation, effectively prevents DHT + INS-induced defects in endometrial receptivity and decidualization gene expression, restores uterine mitochondrial homeostasis, and increases the pregnancy rate and the numbers of viable fetuses. This study adds to our understanding of the mechanisms underlying poor pregnancy outcomes in PCOS patients and the possible therapeutic use of anti-androgens, including flutamide, after spontaneous conception.
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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- Wang, Tao, et al.
(författare)
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Differential Expression Patterns of Glycolytic Enzymes and Mitochondria-Dependent Apoptosis in PCOS Patients with Endometrial Hyperplasia, an Early Hallmark of Endometrial Cancer, In Vivo and the Impact of Metformin In Vitro.
- 2019
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Ingår i: International journal of biological sciences. - : Ivyspring International Publisher. - 1449-2288. ; 15:3, s. 714-725
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Tidskriftsartikel (refereegranskat)abstract
- The underlying mechanisms of polycystic ovarian syndrome (PCOS)-induced endometrial dysfunction are not fully understood, and although accumulating evidence shows that the use of metformin has beneficial effects in PCOS patients, the precise regulatory mechanisms of metformin on endometrial function under PCOS conditions have only been partially explored. To address these clinical challenges, this study aimed to assess the protein expression patterns of glycolytic enzymes, estrogen receptor (ER), and androgen receptor (AR) along with differences in mitochondria-dependent apoptosis in PCOS patients with and without endometrial hyperplasia in vivo and to investigate the effects of metformin in PCOS patients with endometrial hyperplasia in vitro. Here, we showed that compared to non-PCOS patients and PCOS patients without hyperplasia, the endometria from PCOS patients with hyperplasia had a distinct protein expression pattern of glycolytic enzymes, including pyruvate kinase isozyme M2 isoform (PKM2) and pyruvate dehydrogenase (PDH), and mitochondrial transcription factor A (TFAM). In PCOS patients with endometrial hyperplasia, increased glandular epithelial cell secretion and infiltrated stromal cells in the glands were associated with decreased PDH immunoreactivity in the epithelial cells. Using endometrial tissues from PCOS patients with hyperplasia, we found that in response to metformin treatment in vitro, hexokinase 2 (HK2) expression was decreased, whereas phosphofructokinase (PFK), PKM2, and lactate dehydrogenase A (LDHA) expression was increased compared to controls. Although there was no change in PDH expression, metformin treatment increased the expression of TFAM and cleaved caspase-3. Moreover, our in vivo study showed that while endometrial ERβ expression was no different between non-PCOS and PCOS patients regardless of whether or not hyperplasia was present, ERα and AR protein expression was gradually increased in women with PCOS following the onset of endometrial hyperplasia. Our in vitro study showed that treatment with metformin inhibited ERα expression without affecting ERβ expression. Our findings suggest that decreased glycolysis and increased mitochondrial activity might contribute to the onset of ERα-dependent endometrial hyperplasia and that metformin might directly reverse impaired glycolysis and normalize mitochondrial function in PCOS patients with endometrial hyperplasia.
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| 7. |
- Zhang, Yuehui, et al.
(författare)
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Hyperandrogenism and insulin resistance modulate gravid uterine and placental ferroptosis in PCOS-like rats. : Uterine and placental ferroptosis in pregnant PCOS-like rats
- 2020
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 246:3, s. 247-63
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies in rats showed that maternal exposure to 5α-dihydrotestosterone (DHT) and insulin (INS) from gestational day 7.5 to 13.5 induces hyperandrogenism and insulin resistance (HAIR) and subsequently leads to placental insufficiency and fetal loss. We therefore hypothesized that maternal HAIR triggers ferroptosis in the uterus and placenta in association with fetal loss in pregnant rats. Compared with controls, we found that co-exposure to DHT and INS led to decreased levels of Gpx4 and glutathione (GSH), increased GSH+glutathione disulfide (GSSG) and malondialdehyde (MDA), aberrant expression of ferroptosis-associated genes (Acsl4, Tfrc, Slc7a11, and Gclc), increased iron deposition, and activated ERK/p38/JNK phosphorylation in the gravid uterus. However, in the placenta, DHT and INS exposure only partially altered the expression of ferroptosis-related markers (e.g., Gpx4, GSH+GSSG, MDA, Gls2 and Slc7a11 mRNAs, and phosphorylated p38 levels). In the uteri co-exposed to DHT and INS, we also observed shrunken mitochondria with electron-dense cristae, and increased Dpp4 mRNA expression. In contrast, in placentas co-exposed to DHT and INS we found decreased Dpp4 mRNA expression and increased Cisd1 mRNA expression. Further, DHT+INS-exposed pregnant rats exhibited decreased apoptosis in the uterus and increased necroptosis in the placenta. Our findings suggest that maternal HAIR causes the activation of ferroptosis in the gravid uterus and placenta, although this is mediated via different mechanisms operating at the molecular and cellular levels. Furthermore, our data suggest other cell death pathways may play a role in coordinating or compensating for HAIR-induced ferroptosis when the gravid uterus and placenta are dysfunctional.
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| 8. |
- Zhang, Yuehui, et al.
(författare)
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Hyperandrogenism and insulin resistance modulate gravid uterine and placental ferroptosis in PCOS-like rats.
- 2020
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Ingår i: Journal of Endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 246:3, s. 247-263
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies in rats showed that maternal exposure to 5α-dihydrotestosterone (DHT) and insulin (INS) from gestational day 7.5 to 13.5 induces hyperandrogenism and insulin resistance (HAIR) and subsequently leads to placental insufficiency and fetal loss. We therefore hypothesized that maternal HAIR triggers ferroptosis in the uterus and placenta in association with fetal loss in pregnant rats. Compared with controls, we found that co-exposure to DHT and INS led to decreased levels of Gpx4 and glutathione (GSH), increased GSH+glutathione disulfide (GSSG) and malondialdehyde (MDA), aberrant expression of ferroptosis-associated genes (Acsl4, Tfrc, Slc7a11, and Gclc), increased iron deposition, and activated ERK/p38/JNK phosphorylation in the gravid uterus. However, in the placenta, DHT and INS exposure only partially altered the expression of ferroptosis-related markers (e.g., Gpx4, GSH+GSSG, MDA, Gls2 and Slc7a11 mRNAs, and phosphorylated p38 levels). In the uteri co-exposed to DHT and INS, we also observed shrunken mitochondria with electron-dense cristae, and increased Dpp4 mRNA expression. In contrast, in placentas co-exposed to DHT and INS we found decreased Dpp4 mRNA expression and increased Cisd1 mRNA expression. Further, DHT+INS-exposed pregnant rats exhibited decreased apoptosis in the uterus and increased necroptosis in the placenta. Our findings suggest that maternal HAIR causes the activation of ferroptosis in the gravid uterus and placenta, although this is mediated via different mechanisms operating at the molecular and cellular levels. Furthermore, our data suggest other cell death pathways may play a role in coordinating or compensating for HAIR-induced ferroptosis when the gravid uterus and placenta are dysfunctional.
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| 9. |
- Zhang, Yuehui, et al.
(författare)
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Metformin Ameliorates Uterine Defects in a Rat Model of Polycystic Ovary Syndrome.
- 2017
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 18, s. 157-170
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Tidskriftsartikel (refereegranskat)abstract
- Adult rats treated concomitantly with insulin and human chorionic gonadotropin exhibit endocrine, metabolic, and reproductive abnormalities that are very similar to those observed in polycystic ovary syndrome (PCOS) patients. In this study, we used this rat model to assess the effects of metformin on PCOS-related uterine dysfunction. In addition to reducing androgen levels, improving insulin sensitivity, and correcting the reproductive cycle, metformin treatment induced morphological changes in the PCOS-like uterus. At the molecular and cellular levels, metformin normalized the androgen receptor-mediated transcriptional program and restored epithelial-stromal interactions. In contrast to glucose transport, uterine inflammatory gene expression was suppressed through the PI3K-Akt-NFκB network, but without affecting apoptosis. These effects appeared to be independent of AMPK subunit and autophagy-related protein regulation. We found that when metformin treatment partially restored implantation, several implantation-related genes were normalized in the PCOS-like rat uterus. These results improve our understanding of how metformin rescues the disruption of the implantation process due to the uterine defects that result from hyperandrogenism and insulin resistance. Our data provide insights into the molecular and functional clues that might help explain, at least in part, the potential therapeutic options of metformin in PCOS patients with uterine dysfunction.
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| 10. |
- Hu, Min, et al.
(författare)
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Alterations of endometrial epithelial-mesenchymal transition and MAPK signaling components in women with PCOS are partially modulated by metformin in vitro. : Endometrial EMT and MAPK signaling components in PCOS patients
- 2020
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Ingår i: Molecular human reproduction. - : Oxford University Press (OUP). - 1460-2407. ; 26:5, s. 312-326
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Tidskriftsartikel (refereegranskat)abstract
- Growing evidence suggests that epithelial-mesenchymal transition (EMT) and its regulator mitogen-activated protein kinase (MAPK) contribute to endometria-related reproductive disorders. However, the regulation of EMT and MAPK signaling components in the endometrium from polycystic ovary syndrome (PCOS) patients has not been systematically investigated and remains elusive. In humans, how metformin induces molecular alterations in the endometrial tissues under PCOS conditions is not completely clear. Here, we recruited 7 non-PCOS patients during the proliferative phase (nPCOS), 7 non-PCOS patients with endometrial hyperplasia (nPCOSEH), 14 PCOS patients during the proliferative phase (PCOS), and 3 PCOS patients with endometrial hyperplasia (PCOSEH). Our studies demonstrated that compared with nPCOS, PCOS patients showed decreased Claudin 1 and increased Vimentin and Slug proteins. Similar to increased Slug protein, nPCOSEH and PCOSEH patients showed increased N-cadherin protein. Western blot and immunostaining revealed increased epithelial phosphorylated Cytokeratin 8 (p-CK 8) expression and an increased p-CK 8:CK 8 ratio in PCOS, nPCOSEH, and PCOSEH patients compared to nPCOS patients. Although nPCOSEH and PCOSEH patients showed increased p-ERK1/2 and/or p38 protein levels, the significant increase in p-ERK1/2 expression and p-ERK1/2:ERK1/2 ratio was only found in PCOS patients compared to nPCOS patients. A significant induction of the membrane ERβ immunostaining was observed in the epithelial cells of PCOS and PCOSEH patients compared to nPCOS and nPCOSEH patients. While in-vitro treatment with metformin alone increased Snail and decreased Claudin 1, N-cadherin and α-SMA proteins, concomitant treatment with metformin and E2 increased the expression of CK 8 and Snail proteins and decreased the expression of Claudin 1, ZO-1, Slug and α-SMA proteins. Our findings suggest that the EMT contributes to the switch from a healthy state to a PCOS state in the endometrium, which might subsequently drive endometrial injury and dysfunction. We also provide evidence that metformin differentially modulates EMT protein expression in PCOS patients depending on estrogenic stimulation.
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