Loss of the glucocorticoid receptor causes accelerated ovarian ageing in zebrafish

Reproductive decline in mid-adult females is an established phenotype of the ageing process. Stress and the rise in glucocorticoids (GCs) accelerate reproductive ageing, but little is known about the mechanisms involved. During stress, GCs activate the glucocorticoid receptor (GR), a ubiquitously expressed, ligand-bound transcription factor, to elicit physiological changes for restoring homeostasis. Here, we tested the hypothesis that GC-GR signalling is essential for accelerating reproductive ageing. To test this, we used a ubiquitous GR knockout (GRKO) zebrafish, which is inherently hypercortisolemic, to delineate the role of high cortisol and GR signalling on reproductive ageing. The loss of GR led to premature ovarian ageing, including high frequency of typical and atypical follicular atresia in vitellogenic oocytes, yolk liquefaction and large inflammatory infiltrates. The reduction in oocyte quality was also associated with a decline in ovarian tert expression in the adult GRKO fish compared to the early adult GRKO and adult wild-type zebrafish. Accelerated ovarian ageing also impacted the progeny, including lower breeding success, fecundity, egg fertilization rate and delayed somitogenesis and embryo survival in the adult GRKO fish. We adduce that GR signalling is essential for prolonging the reproductive lifespan and improving the egg quality and embryo viability in zebrafish.

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Role of melatonin on embryo viability in sheep

Reproduction Fertility and Development ◽

10.1071/rd18308 ◽

2019 ◽

Vol 31 (1) ◽

pp. 82 ◽

Cited By ~ 7

Author(s):

José-Alfonso Abecia ◽

Fernando Forcada ◽

María-Isabel Vázquez ◽

Teresa Muiño-Blanco ◽

José A. Cebrián-Pérez ◽

...

Keyword(s):

Pineal Gland ◽

Corpus Luteum ◽

Embryo Quality ◽

Protective Action ◽

Embryo Viability ◽

Embryo Survival ◽

Luteal Function ◽

Seasonal Rhythms ◽

Natural Hormone

Melatonin is a natural hormone synthesised in the pineal gland, the activity of which is regulated by day–night perception and dictates seasonal rhythms in reproduction in ovine species. Exogenous melatonin, administered via subcutaneous implants, is used to prolong the breeding season of ewes and can increase the proportion of pregnant ewes (fertility rate) and litter size. The increased proportion of ewes that become pregnant and the number of lambs born per lambing among melatonin-treated sheep may be caused by increased embryo survival, through enhanced luteal function, reduced antiluteolytic mechanisms, or improved embryo quality. This review focuses on the effects of melatonin on embryo viability and summarises the processes by which this hormone affects the ovary, follicle, oocyte, corpus luteum and embryo. Moreover, the effects of melatonin on the mechanisms of invivo maternal recognition of pregnancy in sheep and the protective action that it appears to have on the invitro procedures that are used to obtain healthy embryos are reviewed.

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Interleukin (IL)-33 is dispensable for Schistosoma mansoni worm maturation and the maintenance of egg-induced pathology in intestines of infected mice

10.21203/rs.3.rs-58017/v2 ◽

2020 ◽

Author(s):

Jean Pierre Kambala Mukendi ◽

Risa Nakamura ◽

Satoshi Uematsu ◽

Shinjiro Hamano

Keyword(s):

Lymph Nodes ◽

Wild Type ◽

Mesenteric Lymph Nodes ◽

Schistosome Infection ◽

Mesenteric Lymph ◽

Type 2 Immunity ◽

Transient Impairment ◽

Inflammatory Infiltrates

Abstract Background: Schistosomes are trematode worms that dwell in their definitive host’s blood vessels, where females lay eggs that need to be discharged into the environment with host excreta to maintain their life cycle. Both worms and eggs require type 2 immunity for their maturation and excretion, respectively. However, immune molecules that orchestrate such immunity remain unclear. IL-33 is one of the epithelium-derived cytokines that induce type 2 immunity in tissues. This study aimed at determining its role in the maturation, reproduction, and excretion of S. mansoni eggs, and in the maintenance of egg-induced pathology in the intestines of mice.Methods: Using S. mansoni-infected IL-33-deficient (IL-33-/-) and wild-type (WT) mice, the morphology of worms and the number of eggs in intestinal tissues were studied at different time points of infection. IL-5 and IL-13 production in spleens and mesenteric lymph nodes were measured. Tissue histology was performed on the terminal ilea of infected and non-infected mice.Results: Morphology-wise, worms from IL-33-/- and WT mice at the fourth and sixth weeks of infection did not differ. The number of eggs in intestinal tissues did not differ much between IL-33-/- and WT mice. In the sixth week of infection, IL-33-/- mice presented impaired type 2 immunity in intestines, characterized by decreased production of IL-5 and IL-13 in mesenteric lymph nodes and fewer inflammatory infiltrates with fewer eosinophils in the ilea. Otherwise there was no difference between IL-33-/- and WT mice in the levels of IL-25 and thymic stromal lymphopoietin (TSLP) in intestinal tissues.Conclusions: Despite its ability to initiate type 2 immunity in tissues, IL-33 alone seems dispensable for S. mansoni maturation and its absence may not affect much the accumulation of eggs in intestinal tissues. The transient impairment of type 2 immunity observed in the intestines, but not spleens, highlights the importance of IL-33 over IL-25 and TSLP in initiating, but not maintaining, locally-induced type 2 immunity in intestinal tissues during schistosome infection. Further studies are needed to decipher the role of each of them in schistosomiasis and clarify the possible interactions that might exist between them.

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Analysis of mice carrying targeted mutations of the glucocorticoid receptor gene argues against an essential role of glucocorticoid signalling for generating adrenal chromaffin cells

Development ◽

10.1242/dev.126.13.2935 ◽

1999 ◽

Vol 126 (13) ◽

pp. 2935-2944 ◽

Cited By ~ 1

Author(s):

S. Finotto ◽

K. Krieglstein ◽

A. Schober ◽

F. Deimling ◽

K. Lindner ◽

...

Keyword(s):

Glucocorticoid Receptor ◽

Chromaffin Cells ◽

Essential Role ◽

Adrenal Chromaffin Cells ◽

Wild Type ◽

Sympathetic Neurones ◽

Adrenal Chromaffin ◽

Deficient Mice

Molecular mechanisms underlying the generation of distinct cell phenotypes is a key issue in developmental biology. A major paradigm of determination of neural cell fate concerns the development of sympathetic neurones and neuroendocrine chromaffin cells from a common sympathoadrenal (SA) progenitor cell. Two decades of in vitro experiments have suggested an essential role of glucocorticoid receptor (GR)-mediated signalling in generating chromaffin cells. Targeted mutation of the GR should consequently abolish chromaffin cells. The present analysis of mice lacking GR gene product demonstrates that animals have normal numbers of adrenal chromaffin cells. Moreover, there are no differences in terms of apoptosis and proliferation or in expression of several markers (e.g. GAP43, acetylcholinesterase, adhesion molecule L1) of chromaffin cells in GR-deficient and wild-type mice. However, GR mutant mice lack the adrenaline-synthesizing enzyme PNMT and secretogranin II. Chromaffin cells of GR-deficient mice exhibit the typical ultrastructural features of this cell phenotype, including the large chromaffin granules that distinguish them from sympathetic neurones. Peripherin, an intermediate filament of sympathetic neurones, is undetectable in chromaffin cells of GR mutants. Finally, when stimulated with nerve growth factor in vitro, identical proportions of chromaffin cells from GR-deficient and wild-type mice extend neuritic processes. We conclude that important phenotypic features of chromaffin cells that distinguish them from sympathetic neurones develop normally in the absence of GR-mediated signalling. Most importantly, chromaffin cells in GR-deficient mice do not convert to a neuronal phenotype. These data strongly suggest that the dogma of an essential role of glucocorticoid signalling for the development of chromaffin cells must be abandoned.

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Fission and PINK-1-mediated mitophagy are required for Insulin/IGF-1 signaling mutant reproductive longevity

10.1101/2021.08.16.456566 ◽

2021 ◽

Author(s):

Vanessa Cota ◽

Coleen T Murphy

Keyword(s):

Mitochondrial Dynamics ◽

Oocyte Quality ◽

Mitochondrial Morphology ◽

Reproductive Aging ◽

Human Aging ◽

Wild Type ◽

C Elegans ◽

Age Related ◽

Receptor Mutant

Women′s reproductive cessation is the earliest sign of human aging and is caused by decreasing oocyte quality. Similarly, C. elegans′ reproduction declines with age and is caused by oocyte quality decline. Aberrant mitochondrial dynamics are a hallmark of age-related dysfunction, but the role of mitochondrial morphology in reproductive aging is largely unknown. We examined the requirements for mitochondrial fusion and fission in oocytes of both wild-type worms and the long-lived, long-reproducing insulin-like receptor mutant daf-2. We find that normal reproduction requires both fusion and fission. By contrast, daf-2 mutants require fission, but not fusion, for reproductive span extension. daf-2 mutant oocytes′ mitochondria are punctate (fissioned) and may be primed for mitophagy, as loss of the mitophagy regulator PINK-1 shortens daf-2′s reproductive span. Our data suggest that daf-2 maintain oocyte mitochondria quality with age via a shift toward punctate mitochondrial morphology and mitophagy to extend reproductive longevity.

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O-209 The impact of sperm DNA fragmentation on pregnancy outcomes depends on oocyte dimorphisms

Human Reproduction ◽

10.1093/humrep/deab128.020 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

D Braga ◽

A Setti ◽

R Provenza ◽

P Guilherme ◽

A Iaconelli ◽

...

Keyword(s):

Dna Fragmentation ◽

Smooth Endoplasmic Reticulum ◽

Oocyte Quality ◽

Fertilization Rate ◽

Sperm Dna Fragmentation ◽

Perivitelline Space ◽

Sperm Dna ◽

Icsi Outcomes ◽

The Impact

Abstract Study question Does the impact of sperm DNA fragmentation (SDF) on Intracytoplasmic sperm injection (ICSI) outcomes depend on the presence of oocyte dimorphisms? Summary answer There is a significant influence of oocyte quality on the impact of SDF on pregnancy outcomes. What is known already Sperm DNA fragmentation has been associated with ICSI outcomes. DNA damage is commonly encountered in human spermatozoa and it has been widely accepted that the oocyte assumes responsibility for the repair and remodelling of both the maternal and paternal genomes during the oocyte-embryo transition. Indeed, spermatozoa with DNA damage can fertilise oocytes and still lead to embryo development due to the oocyte DNA repair capacity. Considering the vital role played by the oocyte in the developmental process, it could be hypostatised that the oocyte quality, translated as oocyte morphology, would influence the machinery responsible for sperm DNA repair after fertilization. Study design, size, duration This cohort study included 3,035 oocytes from 525 patients undergoing ICSI cycles in a university-affiliated IVF-center, between June/2016 and July/2019. Oocytes were split into groups according to the SDF index of the sample used for ICSI: low-fragmentation (<30% SDF, n = 2,277) and high-fragmentation (≥30% SDF, n = 758). Oocytes were evaluated before sperm injection and the dimorphisms were recorded. The influence of SDF index on ICSI outcomes, depending on the presence of oocytes dimorphisms was evaluated. Participants/materials, setting, methods Data was evaluated using generalized linear models (GZLM) followed by Bonferroni post hoc. The results are expressed as mean ± standard error for continuous variables or percentages for dichotomous variables, and p-values. The sample size calculation suggested that a sample of at least 504 subjects had 95% power to detect a 20% effect with a significance level of 5% (α). The study was performed in a private university–affiliated in vitro fertilization (IVF) center. Main results and the role of chance The association of both factors: the presence of oocyte dimorphisms (dark cytoplasm, vacuoles in the ooplasm, and resistant membrane) and high SDF index resulted in the lowest fertilization rate among groups, while oocytes free of these dimorphisms injected with samples with <30% SDF had the highest fertilization rate (p = 0.05, p < 0.01 and p < 0.01 for dark cytoplasm, vacuoles in the ooplasm and resistant membrane respectively). The impact of SDF index on high quality embryos rate on cleavage stage was also influence by the presence smooth endoplasmic reticulum clusters and resistant membrane oocytes (p = 0.013 and p = 0.018). As for the clinical outcomes, the impact of SDF index on the implantation rate was influenced by the presence of vacuoles in the ooplasm (p < 0.01), smooth endoplasmic reticulum clusters (p < 0.01), large perivitelline space (p < 0.01), resistant membrane (p < 0.01), and non-resistant membrane (p < 0.01), while the influence of SDF index on the pregnancy rate was influenced by the presence large perivitelline space (p < 0.01), resistant membrane (p = 0.018) and non-resistant membrane (p < 0.01). The effect of SDF on the miscarriage rate was also increased in the presence of large perivitelline space (p = 0.045), non-resistant membrane (0.037) and centrally located cytoplasmic granular area (p = 0.025). Limitations, reasons for caution The retrospective nature is a limitation. It could be argued that using samples with high SDF index does not necessarily mean that a sperm cell with a fragmented DNA was injected, however, the higher the SDF index, the higher the chance of selecting one with fragmented DNA. Wider implications of the findings The findings presented here highlight the crucial role of male and female factors when facing assisted reproduction. The association of low oocyte quality and high SDF index may lead to impaired results. As the oocyte defect cannot be modified, in vivo upgrading of spermatozoa before the treatment should be encouraged. Trial registration number Not applicable

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Interleukin (IL)-33 is dispensable for Schistosoma mansoni worm maturation, egg excretion, and the maintenance of egg-induced pathology in intestines of mice

10.21203/rs.3.rs-58017/v1 ◽

2020 ◽

Author(s):

Jean Pierre Kambala Mukendi ◽

Risa Nakamura ◽

Satoshi Uematsu ◽

Shinjiro Hamano

Keyword(s):

Lymph Nodes ◽

Wild Type ◽

Mesenteric Lymph Nodes ◽

Schistosome Infection ◽

Mesenteric Lymph ◽

Type 2 Immunity ◽

Transient Impairment ◽

Inflammatory Infiltrates

Abstract Background: Schistosomes are trematode worms that dwell in their definitive host’s blood vessels, where females lay eggs that need to be eliminated in the environment with host excreta to maintain their life cycle. Both worms and eggs require type 2 immunity for their maturation and excretion, respectively. However, immune molecules that orchestrate such immunity remain unclear. IL-33 is one of the epithelium-derived cytokines that induce type 2 immunity in tissues. This study aimed at determining its role in the maturation, reproduction, and excretion of S. mansoni eggs, and in the maintenance of egg-induced pathology in the intestines of mice.Methods: Using S. mansoni-infected IL-33-deficient (IL-33-/-) and wild-type (WT) mice, worm morphology, reproduction, and egg excretion were studied at different time points of infection. IL-5 and IL-13 production in spleens and mesenteric lymph nodes were measured. Tissue histology was performed on the terminal ilea of non- and infected mice.Results: Morphology-wise, worms from IL-33-/- and WT mice at the fourth and sixth weeks of infection did not differ. The worms' reproduction, expressed as eggs per worm pair, as well as the excretion of eggs, expressed as the number of eggs in intestinal tissues, did not differ between IL-33-/- and WT mice. In the sixth week of infection, IL-33-/- mice presented impaired type 2 immunity in intestines, characterized by decreased production of IL-5 and IL-13 in mesenteric lymph nodes and fewer inflammatory infiltrates with fewer eosinophils in the ilea. Besides, there was no difference between IL-33-/- and WT mice in the levels of IL-25 and TSLP in intestinal tissues.Conclusions: Despite its ability to initiate type 2 immunity in tissues, IL-33 alone seems dispensable for S. mansoni maturation, reproduction, and egg excretion. The transient impairment of type 2 immunity observed in the intestines, but not spleens, highlights the importance of IL-33 over IL-25 and TSLP in initiating, but not maintaining, locally induced type 2 immunity in intestinal tissues in schistosome infection. Further studies are needed to decipher the role of each of them in schistosomiasis and clarify the possible interactions that might exist between them.

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Early lethality of embryos derived from transgenic Xenopus females is associated with reduced ovarian grem1 expression

10.1101/268235 ◽

2018 ◽

Author(s):

Caroline W. Beck ◽

Joanna Ward ◽

Lisa Troise ◽

Catherine Brochard

Keyword(s):

Bone Morphogenetic Proteins ◽

Oocyte Quality ◽

Fertilization Rate ◽

Unexpected Finding ◽

Wild Type ◽

Transgenic Lines ◽

Mammalian Embryos ◽

Female Germline ◽

Endogenous Locus

AbstractThe grem1 gene codes a protein that inhibits the action of multiple members of a growth factor family known as bone morphogenetic proteins (BMPs). Certain members of this BMP family can regulate both fecundity and fertility in mammals via their action on oocyte (egg) development, and grem1 has been identified as a marker of oocyte quality in humans. The model amphibian Xenopus laevis is far more fecund than mammals, producing thousands of eggs in a clutch. However, female transgenic frogs carrying grem1 under the control of a stress inducible hsp70 promoter (“G” frogs) produce very few viable offspring. Here, we show that this is not due to reduced fecundity or fertilization rate, but results from a significant reduction in subsequent survival over the first day of development. Embryos that successfully survive for the first day were found to go on to develop normally when compared to their peers. Both the morphology and stage distribution of oocytes from G females appears normal, and oocytes develop at expected rates, although stage VI oocytes were found to have a lower response to in vitro progesterone treatment. Unexpectedly, levels of grem1 mRNA were found to be consistently lower in the female ovaries from four independent G transgenic lines than in wild type ovaries. Both transgenic and wild type offspring were equally affected, confirming a maternal effect. Our study shows that transgenic females with the lowest levels of grem1 transcripts in the ovary have the lowest rates of survival past the first day of amphibian embryogenesis, equivalent to pre-implantation staged mammalian embryos. The reduced expression of grem1 in the oocytes of transgenic females suggests transgene supression of an endogenous locus may occur in the Xenopus female germline, an unexpected finding.

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Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614532 ◽

1999 ◽

Vol 81 (04) ◽

pp. 601-604 ◽

Cited By ~ 55

Author(s):

Hiroyuki Matsuno ◽

Osamu Kozawa ◽

Masayuki Niwa ◽

Shigeru Ueshima ◽

Osamu Matsuo ◽

...

Keyword(s):

Plasminogen Activator ◽

Thrombus Formation ◽

Endothelial Injury ◽

Fibrinolytic System ◽

Tissue Type ◽

Clot Lysis ◽

Wild Type ◽

Type Plasminogen Activator ◽

Pai 1

SummaryThe role of fibrinolytic system components in thrombus formation and removal in vivo was investigated in groups of six mice deficient in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), or plasminogen activator inhibitor-1 (PAI-1) (u-PA-/-, t-PA-/- or PAI-1-/-, respectively) or of their wild type controls (u-PA+/+, t-PA+/+ or PAI-1+/+). Thrombus was induced in the murine carotid artery by endothelial injury using the photochemical reaction between rose bengal and green light (540 nm). Blood flow was continuously monitored for 90 min on day 0 and for 20 min on days 1, 2 and 3. The times to occlusion after the initiation of endothelial injury in u-PA+/+, t-PA+/+ or PAI-1+/+ mice were 9.4 ± 1.3, 9.8 ± 1.1 or 9.7 ± 1.6 min, respectively. u-PA-/- and t-PA-/- mice were indistinguishable from controls, whereas that of PAI-1-/- mice were significantly prolonged (18.4 ± 3.7 min). Occlusion persisted for the initial 90 min observation period in 10 of 18 wild type mice and was followed by cyclic reflow and reocclusion in the remaining 8 mice. At day 1, persistent occlusion was observed in 1 wild type mouse, 8 mice had cyclic reflow and reocclusion and 9 mice had persistent reflow. At day 2, all injured arteries had persistent reflow. Persistent occlusion for 90 min on day 0 was observed in 3 u-PA-/-, in all t-PA-/- mice at day 1 and in 2 of the t-PA-/-mice at day 2 (p <0.01 versus wild type mice). Persistent patency was observed in all PAI-1-/- mice at day 1 and in 5 of the 6 u-PA-/- mice at day 2 (both p <0.05 versus wild type mice). In conclusion, t-PA increases the rate of clot lysis after endothelial injury, PAI-1 reduces the time to occlusion and delays clot lysis, whereas u-PA has little effect on thrombus formation and spontaneous lysis.

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