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- Barroso, A., et al.
(författare)
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Neonatal exposure to androgens dynamically alters gut microbiota architecture
- 2020
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Ingår i: Journal of Endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 247:1, s. 69-85
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Tidskriftsartikel (refereegranskat)abstract
- Gonadal steroids strongly contribute to the metabolic programming that shapes the susceptibility to the manifestation of diseases later in life, and the effect is often sexually dimorphic. Microbiome signatures, together with metabolic traits and sex steroid levels, were analyzed at adulthood in neonatally androgenized female rats, and compared with those of control male and female rats. Exposure of female rats to high doses of androgens on early postnatal life resulted in persistent alterations of the sex steroid profile later on life, namely lower progesterone and higher estr adiol and estrone levels, with no effect on endogenous androgens. Neonatally androgenized females were heavier (10% at early adulthood and 26% at adulthood) than controls and had impaired glucose homeostasis observed by higher AUC of glucose in GTT and ITT when subjected to obesogenic manipulations. Androgenized female displayed overt alterations in gut microbiota, indicated especially by higher Bacteroidetes and lower Firmicutes abundance at early adulthood, which disappeared when animals were concurrently overfed at adulthood. Notably, these changes in gut microbiota were related with the intestinal expression of several miRNAs, such as miR-27a-3p, miR-29a-5p, and miR-100-3p. Our results suggest that nutritional and hormonal disruption at early developmental periods not only alters the metabolic programming of the individual later in life but also perturbs the architecture of gut microbiota, which may interact with the host by a cross-talk mediated by intestinal miRNAs; phenomena that may contribute to amplify the metabolic derangement caused by obesity, as seen in neonatally androgenized female rats.
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| 2. |
- Roa, J., et al.
(författare)
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Dicer ablation in Kiss1 neurons impairs puberty and fertility preferentially in female mice
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Kiss1 neurons, producing kisspeptins, are essential for puberty and fertility, but their molecular regulatory mechanisms remain unfolded. Here, we report that congenital ablation of the microRNA-synthesizing enzyme, Dicer, in Kiss1 cells, causes late-onset hypogonadotropic hypogonadism in both sexes, but is compatible with pubertal initiation and preserved Kiss1 neuronal populations at the infantile/juvenile period. Yet, failure to complete puberty and attain fertility is observed only in females. Kiss1-specific ablation of Dicer evokes disparate changes of Kiss1-cell numbers and Kiss1/kisspeptin expression between hypothalamic subpopulations during the pubertal-transition, with a predominant decline in arcuate-nucleus Kiss1 levels, linked to enhanced expression of its repressors, Mkrn3, Cbx7 and Eap1. Our data unveil that miRNA-biosynthesis in Kiss1 neurons is essential for pubertal completion and fertility, especially in females, but dispensable for initial reproductive maturation and neuronal survival in both sexes. Our results disclose a predominant miRNA-mediated inhibitory program of repressive signals that is key for precise regulation of Kiss1 expression and, thereby, reproductive function. Kiss1 neurons are essential for puberty and fertility. Here, the authors show that canonical microRNA biosynthesis in Kiss1 neurons plays an essential role in the control of puberty and fertility, especially in females, likely via repression of repressors on the Kiss1 gene.
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| 3. |
- Ruohonen, S. T., et al.
(författare)
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Selective loss of kisspeptin signaling in oocytes causes progressive premature ovulatory failure
- 2022
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Ingår i: Human Reproduction. - : Oxford University Press (OUP). - 0268-1161 .- 1460-2350. ; 37:4, s. 806-821
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Tidskriftsartikel (refereegranskat)abstract
- STUDY QUESTION Does direct kisspeptin signaling in the oocyte have a role in the control of follicular dynamics and ovulation? SUMMARY ANSWER Kisspeptin signaling in the oocyte plays a relevant physiological role in the direct control of ovulation; oocyte-specific ablation of kisspeptin receptor, Gpr54, induces a state of premature ovulatory failure in mice that recapitulates some features of premature ovarian insufficiency (POI). WHAT IS KNOWN ALREADY Kisspeptins, encoded by the Kiss1 gene, are essential for the control of ovulation and fertility, acting primarily on hypothalamic GnRH neurons to stimulate gonadotropin secretion. However, kisspeptins and their receptor, Gpr54, are also expressed in the ovary of different mammalian species, including humans, where their physiological roles remain contentious and poorly characterized. STUDY DESIGN, SIZE, DURATION A novel mouse line with conditional ablation of Gpr54 in oocytes, named OoGpr54(-/-), was generated and studied in terms of follicular and ovulatory dynamics at different age-points of postnatal maturation. A total of 59 OoGpr54(-/-) mice and 47 corresponding controls were analyzed. In addition, direct RNA sequencing was applied to ovarian samples from 8 OoGpr54(-/-) and 7 control mice at 6 months of age, and gonadotropin priming for ovulatory induction was conducted in mice (N = 7) from both genotypes. PARTICIPANTS/MATERIALS, SETTING, METHODS Oocyte-selective ablation of Gpr54 in the oocyte was achieved in vivo by crossing a Gdf9-driven Cre-expressing transgenic mouse line with a Gpr54 LoxP mouse line. The resulting OoGpr54(-/-) mouse line was subjected to phenotypic, histological, hormonal and molecular analyses at different age-points of postnatal maturation (Day 45, and 2, 4, 6 and 10-11 months of age), in order to characterize the timing of puberty, ovarian follicular dynamics and ovulation, with particular attention to identification of features reminiscent of POI. The molecular signature of ovaries from OoGpr54(-/-) mice was defined by direct RNA sequencing. Ovulatory responses to gonadotropin priming were also assessed in OoGpr54(-/-) mice. MAIN RESULTS AND THE ROLE OF CHANCE Oocyte-specific ablation of Gpr54 caused premature ovulatory failure, with some POI-like features. OoGpr54(-/-) mice had preserved puberty onset, without signs of hypogonadism. However, already at 2 months of age, 40% of OoGpr54(-/-) females showed histological features reminiscent of ovarian failure and anovulation. Penetrance of the phenotype progressed with age, with >80% and 100% of OoGpr54(-/-) females displaying complete ovulatory failure by 6- and 10 months, respectively. This occurred despite unaltered hypothalamic Gpr54 expression and gonadotropin levels. Yet, OoGpr54(-/-) mice had decreased sex steroid levels. While the RNA signature of OoGpr54(-/-) ovaries was dominated by the anovulatory state, oocyte-specific ablation of Gpr54 significantly up- or downregulated of a set of 21 genes, including those encoding pituitary adenylate cyclase-activating polypeptide, Wnt-10B, matrix-metalloprotease-12, vitamin A-related factors and calcium-activated chloride channel-2, which might contribute to the POI-like state. Notably, the anovulatory state of young OoGpr54(-/-) mice could be rescued by gonadotropin priming. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION Conditional ablation of Gpr54 in oocytes unambiguously caused premature ovulatory failure in mice; yet, the ultimate molecular mechanisms for such state of POI can be only inferred on the basis of RNAseq data and need further elucidation, since some of the molecular changes observed in OoGpr54(-/-) ovaries were secondary to the anovulatory state. Direct translation of mouse findings to human disease should be made with caution since, despite the conserved expression of Kiss1/kisspeptin and Gpr54 in rodents and humans, our mouse model does not recapitulate all features of common forms of POI. WIDER IMPLICATIONS OF THE FINDINGS Deregulation of kisspeptin signaling in the oocyte might be an underlying, and previously unnoticed, cause for some forms of POI in women. STUDY FUNDING/COMPETING INTEREST(S) This work was primarily supported by a grant to M.P. and M.T.-S. from the FiDiPro (Finnish Distinguished Professor) Program of the Academy of Finland. Additional financial support came from grant BFU2017-83934-P (M.T.-S.; Ministerio de Economia y Competitividad, Spain; co-funded with EU funds/FEDER Program), research funds from the IVIRMA International Award in Reproductive Medicine (M.T.-S.), and EFSD Albert Renold Fellowship Programme (S.T.R.). The authors have no conflicts of interest to declare in relation to the contents of this work.
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