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- Farman, H. H., et al.
(författare)
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Female mice lacking estrogen receptor-α in hypothalamic proopiomelanocortin (POMC) neurons display enhanced estrogenic response on cortical bone mass
- 2016
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 157:8, s. 3242-3252
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Tidskriftsartikel (refereegranskat)abstract
- Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor(ER)α.CentralERα exertsaninhibitoryroleonbonemass.ERα ishighlyexpressedinthearcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ERα in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ERα expression specifically in POMC neurons (POMC-ERα -/- ). Female POMC-ERα -/- and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 μg/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ERα -/- mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+126 ± 34%, P < .01) and mechanical strength (+193 ± 38%, P < .01). To test whether ERα in VMN is involved in the regulation of bone mass, ERα was silenced using an adeno-associated viral vector. Silencing of ERα in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ERα in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ERα activity in hypothalamic POMC neurons in ARC and stimulatory peripheral ERaα-mediated effects in bone determines cortical bone mass in female mice.
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| 2. |
- Bekris, L. M., et al.
(författare)
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GAD65 autoantibody epitopes in adult patients with latent autoimmune diabetes following GAD65 vaccination
- 2007
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Ingår i: Diabetic Medicine. - : Wiley. - 1464-5491 .- 0742-3071. ; 24:5, s. 521-526
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Tidskriftsartikel (refereegranskat)abstract
- Aims Subcutaneous injection of recombinant human GAD65 (rhGAD65) in patients with latent autoimmune diabetes in adults (LADA) correlates with an increase in C-peptide levels. In this study we analysed the effect of rhGAD65 administration on the GAD65-specific autoimmune response. Methods Longitudinal serum samples obtained from LADA patients (n = 47) who received 4, 20, 100 or 500 mu g alum-formulated rhGAD65 or placebo by subcutaneous injection twice (4 weeks apart) were analysed for their epitope recognition using GAD65-specific recombinant Fab and GAD65/67 fusion proteins. Results Overall, minor changes in the epitope pattern were observed using either approach. Only in the 500-mu g dosage group was an increase in GAD65Ab level associated with a significant increase in the binding to a conformational epitope located at the middle part of GAD65. Conclusions Our data suggest that the apparent beneficial effects of 20 mu g alum-formulated recombinant human GAD65 is not explained by changes in the GAD65Ab epitope pattern.
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