Malmö University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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
Functional importance of estrogen receptors in the periodontium
Malmö högskola, Faculty of Odontology (OD).
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [sv]

Östrogen är ett kvinnligt könshormon som även har andra effekter. Östrogen verkar i cellkärnan genom att binda till en östrogenreceptor (ER), som finns i två olika typer, ERα och ERβ. Parodontit (tandlossning) är en inflammationssjukdom som drabbar tandens fäste som svar på bakterier som normalt finns i munhålan. I cellmembranet hos vissa bakterier finns en molekyl, LPS, som fungerar retande och startar inflammationen genom att binda till en mottagarmolekyl, som sitter på vita blodkroppar, men också till vävnadsceller som till exempel PDL celler. Effekten blir att cellerna börjar producera ämnen, bland annat cytokiner och kemokiner, som får fler vita blodkroppar att komma till platsen och inflammationen är då ett faktum. Sedan tidigare finns ett flertal studier som visar ett samband mellan förändringar i östrogennivåer och tandlossning men mekanismerna är inte kända. Det övergripande syftet med studierna i denna avhandling var att undersöka ERs betydelse i parodontiet.*Studie I: LPS får PDL-celler att drastiskt öka produktionen av inflammationsproteinerna, IL-6och MCP-1 men påverkar inte PDL-cellers normala funktioner, vilket betyder att LPS specifikt stimulerar produktionen av inflammationsproteiner i dessa celler.*Studie II: För att studera effekten av östrogen i parodontiet opererades de östrogenproducerandeäggstockarna bort på en grupp av honmöss. Tändernas fästenivå hos denna grupp jämfördes med en kontrollgrupp med normal östrogenproduktion. Efter sex veckor visade det sig inte vara någon skillnad på tandfästet mellan de två grupperna.*Studie III: Östrogen påverkar PDL-cellers produktion av flera olika inflammationsproteiner, men mönstret är komplext. Ett protein som stimulerar rekrytering av vita blodkroppar (kemokin) hämmas av östrogen medan en annan kemokin förblir oförändrad . För ett tredje kemokin skilde produktionen sig åt beroende på vilket genetiskt ursprung cellerna hade. Detta tyder på att östrogen verkar både pro- och anti-inflammatoriskt och att det genetiska ursprungetkan påverka östrogens funktion.*Studie IV: I tandköttet (gingivan) är ERβ är den dominerande östrogenreceptorn. Mönstret gårigen både på odlade celler och på vävnadsprover från patienter. Vid höga doser av östrogen minskar förmågan att dela sig hos gingivala epitelceller. Studien visar att östrogen verkar genom ERβ i tandköttet och att höga östrogenhalter minskar gingivala epitelcellers förmåga att dela sig.*Studie V: PDL-celler producerar olika mängder av inflammationsproteinet IL-6, beroende på vilket LPS de behandlas med. LPS från den parodontitassocierade bakterien, P. gingivalis orsakar ingen IL-6 produktion i PDL-celler medan LPS från tarmbakterien E. coli ökar IL-6 produktionen med cirka 30 gånger. När enzymen, som behövs vid bildandet av kväveoxid(NO), blockerades minskade IL-6 produktionen som svar på E. coli LPS med 30% vilket indikerar att NO är inblandat i IL-6 produktionen. Sammanfattningsvis visar studierna att östrogen, sannolikt via ERβ, påverkar parodontiets celler på flera olika sätt. Östrogen utövar både effekter som kan tolkas som skyddande (minskning av produktionen av inflammationsproteiner) men också effekter som kan innebära reducerat skydd (t ex hämning av gingivala epitelcellers celldelning). Studierna bidrar med nykunskap om den biologiska betydelsen av östrogen i parodontiet.

Abstract [en]

The main functions of estrogen are associated with reproduction. However, estrogen has been shown to be of functional importance also in non-classic target organs. Previous studies, especially epidemiologicand clinical ones, have addressed estrogen’s influence on periodontitis, suggesting that estrogen has a beneficial effect, but the biological mechanisms have not been identified. Estrogen exerts genomic effects in the target cells by binding to the nuclear receptors, estrogen receptor (ERs), ERα and ERβ. The expression of the two subtypes of ERs varies depending on the tissue. The overall objectives of this thesis were to study the functional importanceof estrogen receptors in the periodontium with special focus on inflammation, and stimulators of inflammation and their signaling pathways. The thesis is based on the following five papers.In Paper I, effects of estrogen on E. coli LPS-induced PDL cell production of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and C-reactive protein (CRP) are assessed, by usingELISA. Furthermore, effects of LPS and estrogen on the normal characteristics of the PDL cell such as collagen synthesis and cell proliferation is determined by using L-[3H]proline incorporationand measurement of DNA synthesis, respectively. Key findings: E.coli LPS stimulates PDL cell IL-6 and MCP-1 production but has no effect on the normal physiological properties of PDL cells. LPSinducedIL-6 and MCP-1 is not reversed by estrogen suggestingthat estrogen has no anti-inflammatory effect in these experiments.In Paper II, we investigate the effects of ovariectomy and aging on tooth attachment in female mice by using morphometric analysis. Key findings: Withdrawal of female sex hormone production byovariectomy has no effect on alveolar bone height and apical termination of the junctional epithelium. In a second series of experiments these parameters are similar in mice sacrificed at 8-26 weeks of age, suggesting that tooth attachment is preserved with age in mice within a period of six months. In Paper III, the objective is to investigate the regulation of CCL2/MCP-1, CCL3/MIP-1α, and CCL5/RANTES chemokines by estrogen in human PDL cells by determining mRNA transcript levels (using quantitative real-time PCR) and protein levels (usingELISA). Key findings: A physiological concentration of estrogen reduces the expression of CCL3 mRNA by about 40% compared to PDL cells treated with LPS alone. In contrast, inter-individual differences in the effects of estrogen on CCL5 mRNA expressionare observed. These findings indicate that estrogen affects chemokine expression in PDL cells showing a complex pattern involving down-regulation as well as up-regulation of chemokines. Estrogen exerts both anti-inflammatory and pro-inflammatory effectsthrough these mechanisms.In Paper IV, ER expression in human gingival biopsies, and effects of estrogen on cultured gingival epithelial cell (HGEP) proliferation,are investigated. Expression of ERα and ERβ is determined by immunohistochemistry and effects of estrogen on HGEP proliferation monitored by measuring DNA synthesis. Key findings: HGEP cells show strong ERβ immunoreactivity but low ERα immunoreactivity both in vivo and in culture, suggesting that ERβis the predominant ER subtype in HGEP. High, but not low, concentrations of estrogen attenuates proliferation of gingival epithelial cells, indicating a concentration-dependent mechanism.In Paper V, the objective is to investigate the effects of LPS from Escherichia coli and Porphyromonas gingivalis on IL-6 productionin human PDL cells and endothelial cells, and the signaling mechanisms involved. Quantitative real-time PCR is used to determine IL-6 mRNA levels and ELISA to determine IL-6 protein. Key findings: E. coli LPS (but not P. gingivalis LPS) stimulates IL-6 production in PDL cells. Treatment with the non-selective nitric oxide synthase inhibitor L-NAME reduces IL-6 by 30%, while aminoguanidine, an inhibitor of inducible nitric oxide synthase, does not affect IL-6 levels, showing a mechanism probably involving nitric oxide formation via endothelial nitric oxide synthase. Treatment with the glucocorticoid steroid dexamethasone totally prevents E. coli LPS-induced IL-6 in PDL cells.

Place, publisher, year, edition, pages
Malmö University, Faculty of Odontology , 2012. , p. 134
Series
Swedish Dental Journal : Supplement, ISSN 0348-6672 ; 221
Keywords [en]
Estrogen, Estrogen receptors, LPS, Periodontium, PDL cells, Gingival epithelial cells
National Category
Dentistry
Identifiers
URN: urn:nbn:se:mau:diva-7693PubMedID: 22479908Scopus ID: 2-s2.0-84861692279Local ID: 13331ISBN: 978-91-7104-388-7 (print)OAI: oai:DiVA.org:mau-7693DiVA, id: diva2:1404633
Note

Paper V in dissertation as manuscript.

Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-12-02Bibliographically approved
List of papers
1. LPS-induced MCP-1 and IL-6 production is not reversed by oestrogen in human periodontal ligament cells
Open this publication in new window or tab >>LPS-induced MCP-1 and IL-6 production is not reversed by oestrogen in human periodontal ligament cells
2008 (English)In: Archives of Oral Biology, ISSN 0003-9969, E-ISSN 1879-1506, Vol. 58, no 9, p. 896-902Article in journal (Refereed)
Abstract [en]

Department of Periodontology, Faculty of Odontology, Malmö University, SE-205 06 Malmö, Sweden. daniel.jonsson@od.mah.se OBJECTIVE: Periodontal ligament (PDL) cells express oestrogen receptors but the functional importance of oestrogen in PDL cells exposed to bacterial endotoxins is not known. Here we investigate if the inflammation promoter lipopolysaccharide (LPS) affects PDL cell production of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP) and/or normal functional PDL cell characteristics such as collagen synthesis and cell proliferation and if oestrogen modulates the effects of LPS. METHODS: PDL cells were obtained from periodontal ligament of premolars. PDL cells were treated with Escherichia coli LPS in the absence or presence of oestrogen (17beta-oestradiol, E2). Cellular concentration of IL-6, MCP-1 and CRP was determined by enzyme-linked immunosorbent assay (ELISA). Collagen synthesis was determined by l-[3H]proline incorporation. Cell proliferation was assessed by DNA synthesis measurement using [3H]thymidine incorporation. RESULTS: Stimulation with LPS (500 ng/ml to 10 microg/ml) increased IL-6 production in a concentration-dependent manner. Lower concentration (100 ng/ml) of LPS had no effect. LPS-induced stimulation of IL-6 was not reversed by a physiologically high concentration (100 nM) of E2. LPS increased also MCP-1 production which was unaffected by E2. Treatment with E2 alone had no effect on either IL-6 or MCP-1. Stimulation with LPS had no effect on CRP. LPS did not affect collagen synthesis and cell proliferation, reflecting normal physiological properties of PDL cells. CONCLUSIONS: LPS stimulates PDL cell IL-6 and MCP-1 production but has no effect on the normal physiological properties of PDL cells. LPS-induced IL-6 and MCP-1 is not reversed by oestrogen suggesting that oestrogen exerts no anti-inflammatory effect via this mechanism.

National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:mau:diva-15385 (URN)10.1016/j.archoralbio.2008.05.001 (DOI)000258474100013 ()18554572 (PubMedID)2-s2.0-47249116915 (Scopus ID)6766 (Local ID)6766 (Archive number)6766 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-02-05Bibliographically approved
2. Effects of ovariectomy and aging on tooth attachment in female mice assessed by morphometric analysis
Open this publication in new window or tab >>Effects of ovariectomy and aging on tooth attachment in female mice assessed by morphometric analysis
2009 (English)In: Acta Odontologica Scandinavica, ISSN 0001-6357, E-ISSN 1502-3850, Vol. 67, no 1, p. 8-12Article in journal (Refereed)
Abstract [en]

Objective. Non-human primates, dogs, rats, hamsters and ferrets, have frequently been used as laboratory animals in periodontal biology and pathology. In the past, mice have been used less for this purpose, but nowadays attract a lot of interest because gene knockout and transgenic technologies utilize mice primarily. In this study, we investigate the effects of ovariectomy and aging on tooth attachment in female mice. Material and methods. Eight-week-old mice (n=15) were divided into three experimental groups (control, n=5; sham-operated, n=5; ovariectomy, n=5) and ovaries removed bilaterally. Attachment level, assessed by measuring alveolar bone height and apical termination of the junctional epithelium, was determined 6 weeks post-ovariectomy by digital morphometric analysis in sagittal sections of the mandible. The plasma level of the inflammation marker serum amyloid A (SAA) was determined by ELISA. In another series of experiments, tooth attachment was determined in female mice (n=7) at 8–26 weeks of age. Results. Withdrawal of female sex hormone production by ovariectomy had no effect on alveolar bone height and apical termination of the junctional epithelium. The SAA level in plasma was unaffected by removal of the ovaries, suggesting that systemic inflammation is not induced by ovariectomy. Bone height was similar in mice sacrificed at 8–26 weeks of age and apical termination of the junctional epithelium was at the cemento-enamel junction at all ages. Conclusions. Removal of ovarian production of female sex hormones by ovariectomy has no influence on tooth attachment, and further tooth attachment is preserved with age in female mice.

Place, publisher, year, edition, pages
Informa Healthcare, 2009
Keywords
morphometry, mouse, ovariectomy, serum amyloid A, tooth attachment
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:mau:diva-6227 (URN)10.1080/00016350802443474 (DOI)000261847300002 ()18923970 (PubMedID)2-s2.0-58149096294 (Scopus ID)9914 (Local ID)9914 (Archive number)9914 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-02-05Bibliographically approved
3. Differential regulation of chemokine expression by estrogen in human periodontal ligament cells
Open this publication in new window or tab >>Differential regulation of chemokine expression by estrogen in human periodontal ligament cells
Show others...
2010 (English)In: Journal of Periodontal Research, ISSN 0022-3484, E-ISSN 1600-0765, Vol. 45, no 6, p. 796-802Article in journal (Refereed)
Abstract [en]

BACKGROUND AND OBJECTIVE: Estrogen modulates inflammatory responses, but the mechanisms involved have not yet been identified. Periodontal ligament (PDL) cells produce chemokines (a group of chemoattractant molecules that recruit leukocytes) and it has been suggested that estrogen modulates periodontal inflammation by regulating the expression of chemokines by PDL cells. Therefore, the objectives of this study were to investigate the regulation of chemokine ligand 2 [CCL2/monocyte chemoattractant protein 1 (MCP-1)], chemokine ligand 3 [CCL3/macrophage inflammatory protein-1α (MIP-1α)] and chemokine ligand 5 (CCL5/RANTES) by estrogen in human PDL cells. MATERIAL AND METHODS: PDL cells were obtained from the PDL of premolars, extracted for orthodontic reasons, from two boys and two girls (16 and 17 years of age). PDL cell CCL2, CCL3 and CCL5 mRNA transcripts were determined by quantitative real-time PCR. The concentrations of CCL2, CCL3 and CCL5 proteins were determined by ELISAs. RESULTS: Treatment with 0.5 μg/mL of lipopolysaccharide (LPS, from Escherichia coli) + 100 nm 17β-estradiol (E(2) ) for 24 h reduced the expression of CCL3 mRNA by about 40% compared to PDL cells treated with LPS alone. Attenuation of CCL3 mRNA was not associated with a decrease in CCL3 protein within 48 h, suggesting a slow turnover of the CCL3 protein. Interindividual differences in the effects of E(2) on CCL5 mRNA expression were observed. E(2) (100 nm) increased the expression of CCL5 by 40-60% in PDL cells derived from two subjects but reduced the expression of CCL5 by about 30% in cells from another subject. CCL2 mRNA and CCL2 protein were highly expressed, but not regulated by E(2) . Similar data were observed in cells obtained from both boys and girls. CONCLUSION: Regulation, by estrogen, of chemokine expression in PDL cells shows a complex pattern involving the down-regulation as well as the up-regulation of chemokines, suggesting that estrogen exerts both anti-inflammatory and proinflammatory effects through these mechanisms.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2010
Keywords
LPS, PDL cells, chemokine, estrogen
National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-15318 (URN)10.1111/j.1600-0765.2010.01308.x (DOI)000283375500013 ()20701669 (PubMedID)2-s2.0-77958577690 (Scopus ID)10897 (Local ID)10897 (Archive number)10897 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-02-05Bibliographically approved
4. Estrogen regulates DNA synthesis in human gingival epithelial cells displaying strong estrogen receptor β immunoreactivity.
Open this publication in new window or tab >>Estrogen regulates DNA synthesis in human gingival epithelial cells displaying strong estrogen receptor β immunoreactivity.
Show others...
2011 (English)In: Journal of Periodontal Research, ISSN 0022-3484, E-ISSN 1600-0765, Vol. 46, no 5, p. 622-8Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND OBJECTIVE: Estrogen acts via estrogen receptor (ER) α and β. The expression pattern of ERs and their importance in gingival tissues are not fully understood. In this study, we investigate gingival ER expression and effects of estrogen on gingival epithelial cell proliferation.

MATERIAL AND METHODS: Gingival biopsies were obtained from both healthy and diseased sites in three male and three female subjects. Expression of ERα and β was determined by immunohistochemistry. Effects of 17β-estradiol (E(2) ) on cell proliferation, monitored by measuring DNA synthesis, were studied in cultured human gingival epithelial HGEPp.05 cells.

RESULTS: Estrogen receptor β, but not ERα, immunoreactivity was demonstrated in nuclei of epithelial cells in all layers of the gingival epithelium, but also in cells of the lamina propria. No differences were observed between male and female subjects. The same pattern, i.e. high ERβ expression but no ERα expression, was observed in both healthy and diseased sites within each individual. No differences in the intensity of the ERβ immunoreactive signal and the number of ERβ-positive nuclei were observed between healthy and diseased gingiva. Treatment with a physiological concentration of E(2) (10 nm) had no effect on DNA synthesis in ERβ- and ERα-expressing HGEPp.05 cells. In contrast, E(2) at high concentrations (500 nm and 10 μm) reduced DNA synthesis by 60-70%.

CONCLUSION: Human gingival epithelial cells display strong ERβ but low ERα immunoreactivity both in vivo and in culture. Estrogen attenuates gingival epithelial cell DNA synthesis at high but not low concentrations, suggesting a concentration-dependent mechanism.

National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-33173 (URN)10.1111/j.1600-0765.2011.01382.x (DOI)000294074800015 ()21615412 (PubMedID)2-s2.0-80955177486 (Scopus ID)
Available from: 2020-11-04 Created: 2020-11-04 Last updated: 2024-02-05Bibliographically approved
5. Differential effects of LPS from Escherichia coli and Porphyromonas gingivalis on IL-6 production in human periodontal ligament cells
Open this publication in new window or tab >>Differential effects of LPS from Escherichia coli and Porphyromonas gingivalis on IL-6 production in human periodontal ligament cells
Show others...
2013 (English)In: Acta Odontologica Scandinavica, ISSN 0001-6357, E-ISSN 1502-3850, Vol. 71, no 3-4, p. 892-898Article in journal (Refereed)
Abstract [en]

Objective. Periodontal ligament (PDL) cells produce IL-6 upon stimulation with inflammation promoters, but the signaling pathways involved have not been characterized. This study investigates underlying mechanisms behind regulation of PDL cell IL-6 production by E. coli and P. gingivalis LPS. Materials and methods: Human PDL cells, endothelial cells and monocytes were stimulated with E. coli or P. gingivalis LPS in the presence or absence of pharmacological agents in order to disclose pathways involved in LPS signaling. Gene expression and cellular protein levels were assessed by quantitative real-time PCR and ELISA, respectively. Results. Stimulation with LPS from E. coli (1 µg/ml) for 24 h enhanced PDL cell IL-6 expression several fold, demonstrated both on transcript and protein levels, but P. gingivalis LPS (1–5 µg/ml) had no effect. TLR2 mRNA was more highly expressed than TLR4 transcript in PDL cells. Treatment with the non-selective nitric oxide synthase inhibitor L-NAME (100 µM) reduced E. coli LPS-induced PDL cell IL-6 by 30%, while neither aminoguanidine (10 µM), an inhibitor of inducible nitric oxide synthase, nor estrogen (17β-estradiol, 100 nM) influenced IL-6. Treatment with the glucocorticoid dexamethasone (1 µM) totally prevented the E. coli LPS-induced PDL cell IL-6. In endothelial cells, neither E. coli LPS nor P. gingivalis LPS promoted IL-6 production. In monocytes, serving as positive control, both E. coli and P. gingivalis LPS stimulated IL-6. Conclusions. E. coli LPS but not P. gingivalis LPS stimulates PDL cell IL-6 production through a glucocorticoid-sensitive mechanism involving nitric oxide formation, probably via endothelial nitric oxide synthase.

Place, publisher, year, edition, pages
Informa Healthcare, 2013
Keywords
cytokine, LPS, nitric oxide, periodontitis, PDL cells
National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-6255 (URN)10.3109/00016357.2012.734415 (DOI)000322832200076 ()23116357 (PubMedID)2-s2.0-84877303476 (Scopus ID)15618 (Local ID)15618 (Archive number)15618 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-03-06Bibliographically approved

Open Access in DiVA

fulltext(3124 kB)572 downloads
File information
File name FULLTEXT01.pdfFile size 3124 kBChecksum SHA-512
89bc64f593125be7f28865ca3c6591ff1bdbe661d3f2abf572a14810e09d1d498dea546ea37d0f5d14b4de312cd738592649282ada17a2280400304b28344870
Type fulltextMimetype application/pdf

PubMedScopus

Authority records

Nebel, Daniel

Search in DiVA

By author/editor
Nebel, Daniel
By organisation
Faculty of Odontology (OD)
Dentistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 572 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

pubmed
isbn
urn-nbn

Altmetric score

pubmed
isbn
urn-nbn
Total: 344 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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