Article: Lipopolysaccharide and hypoxia-induced HIF-1 activation in human gingival fibroblasts
| Title | Lipopolysaccharide and hypoxia-induced HIF-1 activation in human gingival fibroblasts | ||||
|---|---|---|---|---|---|
| Authors | Li, JP2 Li, FYL1 Xu, A1 Cheng, B3 Tsao, SW1 Fung, ML1 Leung, WK2 | ||||
| Keywords | Cell hypoxia Chronic periodontitis Hypoxia-inducible factor 1α subunit Lipopolysaccharides Toll-like receptor 4 Vascular endothelial growth factor A | ||||
| Issue Date | 2012 | ||||
| Publisher | American Academy of Periodontology. The Journal's web site is located at http://www.perio.org | ||||
| Citation | Journal Of Periodontology, 2012, v. 83 n. 6, p. 816-824 [How to Cite?] DOI: http://dx.doi.org/10.1902/jop.2011.110458 | ||||
| Abstract | Background: We previously reported that chronic periodontal inflammation causes the accumulation of the transcriptional activator hypoxia-inducible factor-1α (HIF-1 α) in human gingival fibroblasts (HGFs) in vivo. Here, evidence is provided that bacterial lipopolysaccharides (LPS) and cellular hypoxia, both associated with periodontitis, can individually, or in combination, lead to the accumulation and activation of HIF-1 in HGF in vitro. Methods: Primary gingival fibroblasts were cultured from human gingival biopsies. HIF-1 α peptide from HGFs treated with Escherichia coli LPS under normoxia or hypoxia was detected by nuclear protein extraction, immunoprecipitation, immunoblotting, and immunocytofluorescence. HIF-1 α transcripts were detected using reverse transcription polymerase chain reaction (PCR). The transcript expression levels of vascular endothelial growth factor-A (VEGF-A), a downstream gene of HIF-1α, were assessed by quantitative real-time PCR. Results: Two HIF-1 α splicing transcription variants were found to be constitutively expressed in HGFs. E. coli LPS induced a dose- and time-dependent nuclear accumulation of HIF-1 α peptide in HGFs. This accumulation could be attenuated by treatment with a Toll-like receptor 4 (TLR4)-neutraliz-ing antibody. Under hypoxia, LPS further increased HIF-1α accumulation in HGFs. VEGF-A transcript expression was upregulated by LPS under both normoxia and hypoxia but was downregulated by pretreatment with TLR4-neutralizing antibody or the specific HIF-1α inhibitor 3-(5'-hydroxymeth-yl-2'-furyl)-1-benzyl indazole. Conclusion: LPS induces the nuclear accumulation of HIF-1 α in HGFs and induces HIF-1 biologic activity under normoxia or hypoxia possibly through TLR4. | ||||
| ISSN | 0022-3492 2011 Impact Factor: 2.602 2011 SCImago Journal Rankings: 0.140 | ||||
| DOI | http://dx.doi.org/10.1902/jop.2011.110458 | ||||
| ISI Accession Number ID | WOS:000305492800017
Funding Information: This project was supported by the University of Hong Kong Small Project Funding Grants 200807176129 and 201007176307 and Seed Funding Grant 200911159126. The authors report no conflicts of interest related to this study. | ||||
| References | References in Scopus | ||||
| Grants | Hypoxia-inducible Factor 1 Alpha Induces Human Gingival Keratinocytes to Express Functional Toll-Like Receptor 4 in vitro and in vivo The effect of LPS/TLR4-induced HIF-1\xE0 on Collagen I Metabolism by Mice Gingival Fibroblasts Lipopolysaccharide Induces Hypoxia-Inducible Factor 1 alpha in Periodontal Epithelium through Toll-like Receptor 4 |
| dc.contributor.author | Li, JP | ||||
|---|---|---|---|---|---|
| dc.contributor.author | Li, FYL | ||||
| dc.contributor.author | Xu, A | ||||
| dc.contributor.author | Cheng, B | ||||
| dc.contributor.author | Tsao, SW | ||||
| dc.contributor.author | Fung, ML | ||||
| dc.contributor.author | Leung, WK | ||||
| dc.date.accessioned | 2012-08-08T08:27:10Z | ||||
| dc.date.available | 2012-08-08T08:27:10Z | ||||
| dc.date.issued | 2012 | ||||
| dc.description.abstract | Background: We previously reported that chronic periodontal inflammation causes the accumulation of the transcriptional activator hypoxia-inducible factor-1α (HIF-1 α) in human gingival fibroblasts (HGFs) in vivo. Here, evidence is provided that bacterial lipopolysaccharides (LPS) and cellular hypoxia, both associated with periodontitis, can individually, or in combination, lead to the accumulation and activation of HIF-1 in HGF in vitro. Methods: Primary gingival fibroblasts were cultured from human gingival biopsies. HIF-1 α peptide from HGFs treated with Escherichia coli LPS under normoxia or hypoxia was detected by nuclear protein extraction, immunoprecipitation, immunoblotting, and immunocytofluorescence. HIF-1 α transcripts were detected using reverse transcription polymerase chain reaction (PCR). The transcript expression levels of vascular endothelial growth factor-A (VEGF-A), a downstream gene of HIF-1α, were assessed by quantitative real-time PCR. Results: Two HIF-1 α splicing transcription variants were found to be constitutively expressed in HGFs. E. coli LPS induced a dose- and time-dependent nuclear accumulation of HIF-1 α peptide in HGFs. This accumulation could be attenuated by treatment with a Toll-like receptor 4 (TLR4)-neutraliz-ing antibody. Under hypoxia, LPS further increased HIF-1α accumulation in HGFs. VEGF-A transcript expression was upregulated by LPS under both normoxia and hypoxia but was downregulated by pretreatment with TLR4-neutralizing antibody or the specific HIF-1α inhibitor 3-(5'-hydroxymeth-yl-2'-furyl)-1-benzyl indazole. Conclusion: LPS induces the nuclear accumulation of HIF-1 α in HGFs and induces HIF-1 biologic activity under normoxia or hypoxia possibly through TLR4. | ||||
| dc.description.grant | Hypoxia-inducible Factor 1 Alpha Induces Human Gingival Keratinocytes to Express Functional Toll-Like Receptor 4 in vitro and in vivo | ||||
| dc.description.grant | The effect of LPS/TLR4-induced HIF-1\xE0 on Collagen I Metabolism by Mice Gingival Fibroblasts | ||||
| dc.description.grant | Lipopolysaccharide Induces Hypoxia-Inducible Factor 1 alpha in Periodontal Epithelium through Toll-like Receptor 4 | ||||
| dc.description.grantcode | 103865 | ||||
| dc.description.grantcode | 101821 | ||||
| dc.description.grantcode | 99155 | ||||
| dc.description.nature | Link_to_subscribed_fulltext | ||||
| dc.identifier.citation | Journal Of Periodontology, 2012, v. 83 n. 6, p. 816-824 [How to Cite?] DOI: http://dx.doi.org/10.1902/jop.2011.110458 | ||||
| dc.identifier.doi | http://dx.doi.org/10.1902/jop.2011.110458 | ||||
| dc.identifier.epage | 824 | ||||
| dc.identifier.hkuros | 198908 | ||||
| dc.identifier.isi | WOS:000305492800017
Funding Information: This project was supported by the University of Hong Kong Small Project Funding Grants 200807176129 and 201007176307 and Seed Funding Grant 200911159126. The authors report no conflicts of interest related to this study. | ||||
| dc.identifier.issn | 0022-3492 2011 Impact Factor: 2.602 2011 SCImago Journal Rankings: 0.140 | ||||
| dc.identifier.issue | 6 | ||||
| dc.identifier.pmid | 22087807 | ||||
| dc.identifier.scopus | eid_2-s2.0-84861792062 | ||||
| dc.identifier.spage | 816 | ||||
| dc.identifier.uri | http://hdl.handle.net/10722/154732 | ||||
| dc.identifier.volume | 83 | ||||
| dc.language | eng | ||||
| dc.publisher | American Academy of Periodontology. The Journal's web site is located at http://www.perio.org | ||||
| dc.publisher.place | United States | ||||
| dc.relation.ispartof | Journal of Periodontology | ||||
| dc.relation.references | References in Scopus | ||||
| dc.subject | Cell hypoxia | ||||
| dc.subject | Chronic periodontitis | ||||
| dc.subject | Hypoxia-inducible factor 1α subunit | ||||
| dc.subject | Lipopolysaccharides | ||||
| dc.subject | Toll-like receptor 4 | ||||
| dc.subject | Vascular endothelial growth factor A | ||||
| dc.title | Lipopolysaccharide and hypoxia-induced HIF-1 activation in human gingival fibroblasts | ||||
| dc.type | Article |
Author Affiliations
- The University of Hong Kong Li Ka Shing Faculty of Medicine
- The University of Hong Kong
- Sun Yat-Sen University