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Bone morphogenetic protein 4 promotes mammalian oogonial stem cell differentiation via Smad1/5/8 signaling.

ABSTRACT: To test whether bone morphogenetic protein 4 (BMP4) directly regulates differentiation of adult mouse ovary-derived oogonial stem cells (OSCs) in vitro.Animal study.Research laboratory.Adult C57BL/6 female mice.After purification from adult ovaries by fluorescence-activated cell sorting, OSCs were cultured without or with BMP4 in the absence or presence of the BMP4 antagonist, Noggin.Rates of in vitro-derived (IVD) oocyte formation and changes in gene expression were assessed.Cultured OSCs expressed BMP receptor (BMPR) 1A (BMPR1A), BMPR1B, and BMPR2, suggesting that BMP signaling can directly affect OSC function. In agreement with this, BMP4 significantly increased the number of IVD oocytes formed by cultured OSCs in a dose-dependent manner, and this response was inhibited in a dose-dependent fashion by cotreatment with Noggin. Exposure of OSCs to BMP4 was associated with rapid phosphorylation of BMPR-regulated Smad1/5/8 proteins, and this response was followed by increased expression of the meiosis initiation factors, stimulated by retinoic acid gene 8 (Stra8), muscle-segment homeobox 1 (Msx1), and Msx2. In keeping with the IVD oocyte formation data, the ability of BMP4 to activate Smad1/5/8 signaling and meiotic gene expression in OSCs was abolished by cotreatment with Noggin.Engagement of BMP4-mediated signaling in adult mouse ovary-derived OSCs cultured in vitro drives differentiation of these cells into IVD oocytes through Smad1/5/8 activation and transcriptional up-regulation of key meiosis-initiating genes.

SUBMITTER: Park ES

PROVIDER: S-EPMC4266321 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

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Bone morphogenetic protein 4 promotes mammalian oogonial stem cell differentiation via Smad1/5/8 signaling.

Park Eun-Sil ES Woods Dori C DC Tilly Jonathan L JL

Fertility and sterility 20130828 5

<h4>Objective</h4>To test whether bone morphogenetic protein 4 (BMP4) directly regulates differentiation of adult mouse ovary-derived oogonial stem cells (OSCs) in vitro.<h4>Design</h4>Animal study.<h4>Setting</h4>Research laboratory.<h4>Animal(s)</h4>Adult C57BL/6 female mice.<h4>Intervention(s)</h4>After purification from adult ovaries by fluorescence-activated cell sorting, OSCs were cultured without or with BMP4 in the absence or presence of the BMP4 antagonist, Noggin.<h4>Main outcome measu ...[more]

PMID: 23993924

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Project description:BackgroundAdipose-derived mesenchymal stem cells (ADMSCs) are a promising source of material source for medical regeneration of cartilage. Growth factors, including transforming growth factor-β (TGFβ) subfamily members and bone morphogenetic proteins (BMPs), play important roles in inducing and promoting chondrogenic differentiation of MSCs. However, these exogenous growth factors have some drawbacks related to their cost, biological half-life, and safety for clinical application. Several studies have reported that statins, the competitive inhibitors of 3-hydroxy-2-methylglutaryl coenzyme A (HMG-CoA) reductase, induce the expression of BMP2 in multiple cell types as the pleotropic effects. The objective of this study was to investigate the effects of fluvastatin during chondrogenic differentiation of human ADMSCs (hADMSCs).MethodsThe effects of fluvastatin were analyzed during chondrogenic differentiation of hADMSCs in the pellet culture without exogenous growth factors by qRT-PCR and histology. For functional studies, Noggin, an antagonist of BMPs, mevalonic acid (MVA) and geranylgeranyl pyrophosphate (GGPP), metabolites of the mevalonate pathway, ROCK inhibitor (Y27632), or RAC1 inhibitor (NSC23766) were applied to cells during chondrogenic differentiation. Furthermore, RhoA activity was measured by RhoA pulldown assay during chondrogenic differentiation with or without fluvastatin. Statistically significant differences between groups were determined by Student's t-test or the Tukey-Kramer test.ResultsFluvastatin-treated cells expressed higher levels of BMP2, SOX9, ACAN, and COL2A1 than control cells, and accumulated higher levels of glycosaminoglycans (GAGs). Noggin significantly inhibited the fluvastatin-mediated upregulation of ACAN and COL2A1. Both MVA and GGPP suppressed the effects of fluvastatin on the expressions of BMP2, SOX9, ACAN, and COL2A1. Furthermore, fluvastatin suppressed the RhoA activity, and inhibition of RhoA-ROCK signaling by Y27632 increased the expressions of BMP2, SOX9, ACAN, and COL2A1, as well as fluvastatin.ConclusionsOur results suggest that fluvastatin promotes chondrogenic differentiation of hADMSCs by inducing endogenous BMP2, and that one of the mechanisms underlying the effects is inhibition of RhoA-ROCK signaling via suppression of GGPP. Fluvastatin is a safe and low-cost compound that holds promise for use in transplantation of hADMSCs for cartilage regeneration.

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Bone morphogenetic protein 4 promotes mammalian oogonial stem cell differentiation via Smad1/5/8 signaling.

Publications

Bone morphogenetic protein 4 promotes mammalian oogonial stem cell differentiation via Smad1/5/8 signaling.

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