uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Expression and regulation of CYP17A1 and 3β-hydroxysteroid dehydrogenase in cells of the nervous system: potential effects of vitamin D on brain steroidogenesis
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. (Steroidbiokemi)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. (Steroidbiokemi)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. (Steroidbiokemi)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
Show others and affiliations
2018 (English)In: Neurochemistry International, ISSN 0197-0186, E-ISSN 1872-9754, Vol. 113, p. 46-55Article in journal (Refereed) Published
Abstract [en]

Steroids are reported to have diverse functions in the nervous system. Enzymatic production of steroid hormones has been reported in different cell types, including astrocytes and neurons. However, the information on some of the steroidogenic enzymes involved is insufficient in many respects. Contradictory results have been reported concerning the relative importance of different cell types in the nervous system for expression of CYP17A1 and 3b-hydroxysteroid dehydrogenase (3b-HSD). 3b-HSD is important in all basic steroidogenic pathways and CYP17A1 is required to form sex hormones. In the current investigation we studied the expression of these enzymes in cultured primary rat astrocytes, in neuron-enriched cells from rat cerebral cortex and in human neuroblastoma SH-SY5Y cells, a cell line often used as an in vitro model of neuronal function and differentiation. As part of this study we also examined potential effects on CYP17A1 and 3b-HSD by vitamin D, a compound previously shown to have regulatory effects in steroid hormone-producing cells outside the brain. The results of our study indicate that astrocytes are a major site for expression of 3b-HSD whereas expression of CYP17A1 is found in both astrocytes and neurons. The current data suggest that neurons, contrary to some previous reports, are not involved in 3b-HSD reactions. Previous studies have shown that vitamin D can influence gene expression and hormone production by steroidogenic enzymes in some cells. We found that vitamin D suppressed CYP17A1-mediated activity by 20% in SH-SY5Ycells and astrocytes. Suppression of CYP17A1 mRNA levels was considerably stronger, about 50% in SH-SY5Y cells and 75% in astrocytes. In astrocytes 3b-HSD was also suppressed by vitamin D, about 20% at the enzyme activity level and 60% at the mRNA level. These data suggest that vitamin D-mediated regulation of CYP17A1 and 3b-HSD, particularly on the transcriptional level, may play a role in the nervous system.

Place, publisher, year, edition, pages
2018. Vol. 113, p. 46-55
Keywords [en]
vitamin D, brain, metabolism, neurons, astrocytes, neurosteroids
National Category
Biochemistry and Molecular Biology
Research subject
Biochemistry
Identifiers
URN: urn:nbn:se:uu:diva-333916DOI: 10.1016/j.neuint.2017.11.007ISI: 000428495900005PubMedID: 29162485OAI: oai:DiVA.org:uu-333916DiVA, id: diva2:1158235
Available from: 2017-11-18 Created: 2017-11-18 Last updated: 2018-07-19Bibliographically approved
In thesis
1. Expression and regulation of steroid metabolizing enzymes in cells of the nervous and skeletal systems: Special focus on vitamin D metabolism
Open this publication in new window or tab >>Expression and regulation of steroid metabolizing enzymes in cells of the nervous and skeletal systems: Special focus on vitamin D metabolism
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Little is known about the mechanisms of vitamin D actions in the brain and bone. In this study, the metabolism of vitamin D and its regulation in various cell cultures of the nervous and skeletal systems were examined.

Human osteosarcoma Saos-2 cells, human primary osteoblasts (hOB) and murine motor neuron-like NSC-34 cells were found to express mRNA for all enzymes required in vitamin D3 metabolism as well as the vitamin D receptor (VDR) that mediates vitamin D actions. Also, production of 24,25-dihydroxyvitamin D3 was found in these cells. Studies on vitamin D metabolism in NSC-34 cells and in primary neuron-enriched cells from rat cerebral cortex indicate formation of a previously unknown major metabolite formed from 25-hydroxyvitamin D3. Evaluation of the NSC-34 cells suggests that this cell line could be a novel model for studies of neuronal vitamin D metabolism and its regulation by endogenous and exogenous compounds.

Treatment with glucocorticoids down regulated mRNA expression for the CYP24A1 gene in Saos-2 and hOB cells. Additionally, the glucocorticoid prednisolone showed suppression of CYP24A1-mediated metabolism and CYP24A1 promoter activity in Saos-2 cells. In NSC-34 cells, CYP24A1 mRNA levels were up-regulated by prednisolone, 1α,25-dihydroxyvitamin D3 and its synthetic analogues, EB1089 and tacalcitol. Formation of an endogenous glucocorticoid, 11-deoxycortisol, was observed in Saos-2 cells. Effects of glucocorticoids on the vitamin D system in bone cells may contribute to the adverse side effects in long-term treatment with glucocorticoids. Also, there may be a correlation between the administration of corticosteroids and adverse effects in the CNS.

Expression and effects of vitamin D on steroidogenic enzymes were studied in primary neuron-enriched rat cortex cells, primary rat astrocytes and human neuroblastoma SH-SY5Y cells. These different cell cultures all expressed CYP17A1, whereas only astrocytes expressed 3β-hydroxysteroid dehydrogenase (3β-HSD). 1α,25-Dihydroxyvitamin D3 suppressed mRNA levels and enzyme activity of CYP17A1 in SH-SY5Y cells and astrocytes. 1α,25-Dihydroxyvitamin D3 suppressed enzyme activity and mRNA levels of 3β-HSD in astrocytes. The results suggest that vitamin D-mediated regulation of CYP17A1 and 3β-HSD may play a role in the nervous system.

The results presented here contribute to our understanding of vitamin D metabolism and effects of glucocorticoids in the brain and bone.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 58
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, ISSN 1651-6192 ; 242
National Category
Chemical Sciences Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-333920 (URN)978-91-513-0154-9 (ISBN)
Public defence
2018-01-18, B7:101a, BMC, Husargatan 3, Uppsala, 13:15 (Swedish)
Opponent
Supervisors
Available from: 2017-12-21 Created: 2017-11-19 Last updated: 2018-03-08
2. Steroids and steroid-metabolizing enzymes in the nervous system: Special focus on cell survival and sex hormone synthesis
Open this publication in new window or tab >>Steroids and steroid-metabolizing enzymes in the nervous system: Special focus on cell survival and sex hormone synthesis
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Some steroids in the brain and peripheral nervous system have been shown to have neuroprotective effects but the knowledge is limited. The present study examines the effects of steroids including oxysterols, vitamin D and vitamin D analogs on cell viability/growth and steroidogenesis in the nervous system.

Both 24- and 27-hydroxycholesterol reduced staurosporine-induced toxicity in human neuroblastoma SH-SY5Y cells. In addition, 27-hydroxycholesterol decreased the staurosporine-mediated induction of caspases, known to be important in apoptotic events. From the findings it may be concluded that effects of oxysterols on cellular viability are dependent on the concentration and on the type of oxysterol. 24-Hydroxycholesterol was also found to attenuate oxidative stress both in SH-SY5Y cells and astrocytes. The results indicate that during some conditions, oxysterols may have neuroprotective effects.

The vitamin D analogs tacalcitol and calcipotriol strongly reduced proliferation, cell viability and migration of human glioblastoma T98G cells, similarly as 1,25(OH)2D3 , the physiological form of vitamin D. Glioblastoma is the most lethal type of primary tumors in the CNS. These findings suggest that vitamin D analogs are potential candidates in treatment of brain tumors, most likely in combination with other therapies.

Astrocytes were found to be a major site for expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) whereas expression of CYP17A1 was found in both astrocytes and neurons. 3β-HSD and CYP17A1 are important steroidogenic enzymes. Vitamin D inhibited both CYP17A1- and 3β-HSD -mediated activity and mRNA levels, with a stronger effect on mRNA expression than on enzyme activity. This indicates that 1,25(OH)2D3 could affect the production of sex hormones in the brain.

In summary, results from this thesis contribute to the knowledge on the effects of oxysterols on cell viability and oxidative stress in cells from the CNS. Also the results provide data on the effects of vitamin D in the brain and suggest that vitamin D analogs may be promising candidates for treatment of certain brain tumors.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. p. 54
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, ISSN 1651-6192 ; 236
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Biochemistry
Identifiers
urn:nbn:se:uu:diva-328767 (URN)978-91-513-0056-6 (ISBN)
Public defence
2017-10-20, A1:107, BMC, Husargatan 3, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2017-09-28 Created: 2017-08-31 Last updated: 2018-04-03

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMed

Authority records BETA

Emanuelsson, IdaAlmokhtar, MokhtarWikvall, KjellGröndbladh, AlfhildNylander, ErikSvensson, Anne-LieNorlin, Maria

Search in DiVA

By author/editor
Emanuelsson, IdaAlmokhtar, MokhtarWikvall, KjellGröndbladh, AlfhildNylander, ErikSvensson, Anne-LieNorlin, Maria
By organisation
Department of Pharmaceutical Biosciences
In the same journal
Neurochemistry International
Biochemistry and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 70 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf