Loss of microRNA-7a2 induces hypogonadotropic hypogonadism and infertility
Kashan Ahmed, Mary P. LaPierre, Emanuel Gasser, Rémy Denzler, Yinjie Yang, Thomas Rülicke, Jukka Kero, Mathieu Latreille, Markus Stoffel
Kashan Ahmed, Mary P. LaPierre, Emanuel Gasser, Rémy Denzler, Yinjie Yang, Thomas Rülicke, Jukka Kero, Mathieu Latreille, Markus Stoffel
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Research Article Endocrinology Reproductive biology

Loss of microRNA-7a2 induces hypogonadotropic hypogonadism and infertility

Abstract

MicroRNAs (miRNAs) are negative modulators of gene expression that fine-tune numerous biological processes. miRNA loss-of-function rarely results in highly penetrant phenotypes, but rather, influences cellular responses to physiologic and pathophysiologic stresses. Here, we have reported that a single member of the evolutionarily conserved miR-7 family, miR-7a2, is essential for normal pituitary development and hypothalamic-pituitary-gonadal (HPG) function in adulthood. Genetic deletion of mir-7a2 causes infertility, with low levels of gonadotropic and sex steroid hormones, small testes or ovaries, impaired spermatogenesis, and lack of ovulation in male and female mice, respectively. We found that miR-7a2 is highly expressed in the pituitary, where it suppresses golgi glycoprotein 1 (GLG1) expression and downstream bone morphogenetic protein 4 (BMP4) signaling and also reduces expression of the prostaglandin F2a receptor negative regulator (PTGFRN), an inhibitor of prostaglandin signaling and follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion. Our results reveal that miR-7a2 critically regulates sexual maturation and reproductive function by interconnecting miR-7 genomic circuits that regulate FSH and LH synthesis and secretion through their effects on pituitary prostaglandin and BMP4 signaling.

Authors

Kashan Ahmed, Mary P. LaPierre, Emanuel Gasser, Rémy Denzler, Yinjie Yang, Thomas Rülicke, Jukka Kero, Mathieu Latreille, Markus Stoffel

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Figure 6

miR-7a2 regulates gonadotropin production through BMP and prostaglandin signaling.

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miR-7a2 regulates gonadotropin production through BMP and prostaglandin ...
(A and B) Relative luciferase levels of plasmids carrying WT or mutated 3′ UTRs of Ptgfrn (A) or Glg1 (B) cotransfected in LbT2 cells with or without forced expression of mir-7a2 (n = 3). (C and D) Relative expression levels of gonadotropin genes in cells transfected with siRNA against Ptgfrn (C) or Glg1 (D) (n = 4). (E) Relative expression levels of gonadotropin genes, Cga, Fshb, and Lhb in cells overexpressing Ptgfrn (gray bars) or Glg1 (black bars) for 72 hours (n = 4). (F and G) Relative expression levels of Fshb (F) or Lhb (G) in LbT2 cells that were transfected with siPtgfrn or siCtrl and treated with 100 nM dinoprost or PBS for 4 hours (n = 4). (H) Concentration of LH in supernatants of cells 72 hours after silencing of Ptgfrn (n = 3). (I) Expression levels of Lhb in cells treated with dinoprost (100 nM), GREM1 (0.25 μg/ml), or dinoprost and GREM1 together (n = 3). (J) Western blot analysis of phospho-SMAD1/5/9 or total SMAD1 in lysates of cells pretreated with or without GREM1 (0.25 ug/ml) for 1 hour, followed by 30 minutes of stimulation with BMP4 (50 ng/ml). Shown is 1 representative experiment of 3. All data are represented as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001, ANOVA (E, F, G, I); t test (A, B, C, D, H).