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Yang W, Bai X, Luan X, Min J, Tian X, Li H, Li H, Sun W, Liu W, Fan W, Liu W, Sun L. Delicate regulation of IL-1β-mediated inflammation by cyclophilin A. Cell Rep 2022; 38:110513. [PMID: 35294882 DOI: 10.1016/j.celrep.2022.110513] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/26/2022] [Accepted: 02/17/2022] [Indexed: 01/12/2023] Open
Abstract
The inflammatory response is tightly regulated, but its regulatory principles are still incompletely understood. Cyclophilin A (CypA) has long been considered as a pro-inflammatory factor. Here, we discover how CypA precisely regulates interleukin-1β (IL-1β)-mediated inflammatory responses. In lipopolysaccharide-treated mice, CypA deficiency initially inhibits and then promotes lung inflammation, which is closely related to IL-1β production. Mechanistically, CypA not only facilitates pro-IL-1β processing by increasing Smurf1-mediated K63-linked ubiquitination in an ATP-dependent manner but also accelerates pro-IL-1β degradation, depending on Smurf1-mediated K48-linked ubiquitination. Moreover, in IL-1β-treated mice, CypA exacerbates lung injury by enhancing cytokine production. It also upregulates the ILK/AKT pathway by inhibiting Cyld-mediated K63-linked ILK deubiquitination, which promotes the epithelial-mesenchymal transition (EMT) to facilitate lung repair. Collectively, CypA promotes inflammation activation by increasing IL-1β production and then promotes inflammation resolution by enhancing redundant pro-IL-1β degradation and IL-1β-induced EMT, indicating the complex and delicate regulation of inflammatory response.
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Affiliation(s)
- Wenxian Yang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyuan Bai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaohan Luan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Min
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaodong Tian
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Heqiao Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huizi Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenqiang Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China
| | - Wei Liu
- College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China
| | - Wenhui Fan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenjun Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Microbiology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Beijing 100101, China; Institute of Infectious Diseases, Shenzhen Bay Laboratory, Guangdong 518107, China.
| | - Lei Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China.
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Chen TY, Kuo PJ, Lin CY, Hung TF, Chiu HC, Chiang CY, Shih KC, Fu E. Porphyromonas gingivalis lipopolysaccharide and gingival fibroblast augment MMP-9 expression of monocytic U937 cells through cyclophilin A. J Periodontol 2021; 93:449-457. [PMID: 33999413 DOI: 10.1002/jper.19-0740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 11/07/2022]
Abstract
BACKGROUND Intercellular cross-talking was suggested in matrix metalloproteinase (MMP)-9 expression with unknown mechanisms. Studies showed cyclophilin A (CypA) playing an important role in regulating MMP-9 expression in varied diseases. The aim of the study was to examine the CyPA on the MMP-9 augmentation in monocytic U937 cells after Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) treatment and human gingival fibroblast (hGF) co-culture. METHODS In independent culture or co-culture of hGF and U937 cell, quantitative real-time polymerase chain reaction (qPCR) and zymography were selected to examine the mRNA and protein activity of MMP-9, respectively. The CyPA expression was determined by qPCR. RESULTS LPS could enhance MMP-9 mRNA expression and enzyme activity in U937 cell. However, the enhancements were not observed in hGF. Similarly, LPS enhanced CyPA mRNA in U937, but not in hGF. After co-cultured with hGF, however, MMP-9 and CyPA in U937 increased regardless of the presence/absence of LPS. In U937 cells, the extra-supplied CyPA increased MMP-9 mRNA and enzyme activity, whereas the CyPA inhibitor, cyclosporine A, suppressed the LPS- and co-culture-enhanced MMP-9. Moreover, the inhibitors for MAP kinase, including PD98059 (ERK) and SP600125 (JNK), suppressed the CyPA-enhanced MMP-9 in U937. CONCLUSION Through the CyPA pathway, the LPS and the hGF could augment the MMP-9 expression in the U937 cells.
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Affiliation(s)
- Tzu-Ying Chen
- School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan
| | - Po-Jan Kuo
- School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan
| | - Chi-Yu Lin
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
- Center for Teeth Bank and Dental Stem Cell Technology, Taipei Medical University, Taipei, Taiwan
| | - Tsung-Fu Hung
- School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan
| | - Hsien-Chung Chiu
- School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan
| | - Cheng-Yang Chiang
- School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan
| | - Kuang-Chung Shih
- Division of Endocrinology and Metabolism, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Division of Endocrinology and Metabolism, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Earl Fu
- School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan
- Department of Dentistry, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Xindian, New Taipei City, Taiwan
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Xiao C, Bai G, Du Y, Jiang H, Yu X. Association of high HIF-1α levels in serous periodontitis with external root resorption by the NFATc1 pathway. J Mol Histol 2020; 51:649-658. [PMID: 32990833 DOI: 10.1007/s10735-020-09911-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/16/2020] [Indexed: 01/25/2023]
Abstract
Whether external root resorption is associated with hypoxia in the periodontal ligaments of teeth with severe periodontitis remains unclear. Hypoxia inducible factor-1α (HIF-1α) expression and external resorption sites in the periodontal ligaments of these teeth were observed to elaborate upon the relationship between hypoxia and external root resorption in severe periodontitis. Histological analysis was performed to observe external root resorption. The expressions of HIF-1α and Nuclear factor-activated T cells c1 (NFATc1) in the periodontal ligaments were detected by immunofluorescence, western blotting and real-time PCR. Bone marrow macrophages (BMMs) were stimulated by Porphyromonas gingivalis lipopolysaccharide (Pg.LPS) and cultured under hypoxia in vitro. High levels of HIF-1α and NFATc1 were detected in severe periodontitis. HIF-1α positive-cells were observed in the external resorption sites. Hypoxia promoted Pg.LPS-stimulated osteoclastogenesis of BMMs and bone resorption by the NFATc1 pathway. Increased HIF-1α in severe periodontitis are associated with external root resorption by the NFATc1 pathway.
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Affiliation(s)
- Changjie Xiao
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China
| | - Guangliang Bai
- Department of Oral Medicine, Liaocheng Peoples Hospital, Liaocheng, Shandong, People's Republic of China
| | - Yanmei Du
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China
| | - Huan Jiang
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China.
| | - Xijiao Yu
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China.
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Yue Y, Liu X, Li Y, Xia B, Yu W. The role of TLR4/MyD88/NF-κB pathway in periodontitis-induced liver inflammation of rats. Oral Dis 2020; 27:1012-1021. [PMID: 32853444 PMCID: PMC8247295 DOI: 10.1111/odi.13616] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 07/24/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The aim of this study was to clarify the immune mechanism of hepatic injury induced by periodontitis using a rat model. METHODS Twenty-four SPF male Wistar rats were randomly divided into two groups: control group (CG) and periodontitis group (PG). In order to induce experimental periodontitis, we tied the wire ligature around bilateral maxillary first molar of rats. After 8 weeks, the following indicators were valued: gingival index, tooth mobility, probing pocket depth; indexes about oxidative stress and circulating biomarkers; bone retraction by micro-CT analysis; Toll-like receptor 4 (TLR4), myeloid differential protein-88 (MyD88), and nuclear factor kappa B (NF-κB) by qRT-PCR and Western blotting; tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6) by qRT-PCR and immunohistochemical staining; inflammation of periodontal and hepatic tissues by histopathological observation. RESULTS Periodontal indicators and micro-CT results showed the raised levels of inflammatory response and bone retraction in PG compared with CG. The mRNA and protein levels of TLR4, MyD88, NF-κB, TNF-α, and IL-6 have indicated high values in PG versus CG. Histopathological analysis revealed a correlation between periodontitis and hepatic injury. CONCLUSION TLR4/MyD88/NF-κB pathway may play a role in periodontitis-induced liver inflammation of rats.
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Affiliation(s)
- Yiyun Yue
- Department of Periodontology, Jilin University, Changchun, China
| | - Xinchan Liu
- Department of Geriatric Stomatology, Jilin University, Changchun, China
| | - Yan Li
- Department of Periodontology, Jilin University, Changchun, China
| | - Boyuan Xia
- Department of Periodontology, Jilin University, Changchun, China
| | - Weixian Yu
- Department of Geriatric Stomatology, Jilin University, Changchun, China.,Jilin Provincial Laboratory of Biomedical Engineering, School and Hospital of Stomatology, Jilin University, Changchun, China
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Yu X, Jiang H, Cheng G, Shang W, Zhang S. High levels of HIF-1ɑ in hypoxic dental pulps associated with teeth with severe periodontitis. J Mol Histol 2020; 51:265-275. [PMID: 32394128 DOI: 10.1007/s10735-020-09878-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/04/2020] [Indexed: 12/29/2022]
Abstract
In this study we investigated the expression of HIF-1ɑ in dental pulps of the teeth with severe periodontitis. The expression of HIF-1ɑ in dental pulps of the teeth with severe periodontitis was detected by immunohistochemistry, immunofluorescence and real-time PCR. Bone marrow macrophages (BMMs) were cultured under hypoxia in vitro. HIF-1ɑ, osteoclast-specific factors (NFATc1, CTSK and c-fos) and RANKL-induced osteoclastogenesis were evaluated by immunofluorescence, TRAP staining and western blotting. High levels of HIF-1ɑ protein were detected in dental pulps of teeth with severe periodontitis, whereas few positive HIF-1ɑ expressions were detected in healthy dental pulps. Hypoxia occurred in the dental pulps in response to heavy periodontitis. Many HIF-1ɑ-positive infiltratory inflammatory cells were observed around blood vessels. Tooth internal resorption was found in some teeth with severe periodontitis. The HIF-1ɑ levels were upregulated in BMMs under hypoxia, which also promoted osteoclast formation and resorption by NFATc1, CTSK and c-fos. Teeth with severe periodontitis show hypoxic dental pulps and increased potential of osteoclastic differentiation.
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Affiliation(s)
- Xijiao Yu
- Department of Oral Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, People's Republic of China.,Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China
| | - Huan Jiang
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China
| | - Guannan Cheng
- Department of Orthodontics, Weihai Stomatological Hospital, Weihai, Shandong, People's Republic of China
| | - Wenzhi Shang
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China.
| | - Shanyong Zhang
- Department of Oral Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, People's Republic of China.
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Taskan MM, Balci Yuce H, Karatas O, Gevrek F, Toker H. Evaluation of the effect of oleuropein on alveolar bone loss, inflammation, and apoptosis in experimental periodontitis. J Periodontal Res 2019; 54:624-632. [PMID: 31032945 DOI: 10.1111/jre.12662] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/19/2019] [Accepted: 03/30/2019] [Indexed: 12/13/2022]
Abstract
THE OBJECTIVE The present study aimed to evaluate the effects of oleuropein on ligature-induced alveolar bone loss. In this respect, osteoblastic activity, osteoclastic activity, inflammatory markers, and apoptosis were evaluated. BACKGROUND Oleuropein is a flavonoid, which has potent anti-inflammatory and bone-protective effects. METHODS Thirty-two Wistar rats were divided into four experimental groups as following: control (C, n = 8) group; periodontitis (P, n = 8) group; periodontitis and low-dose oleuropein group (12 mg/kg/day oleuropein, LDO group, n = 8); and periodontitis and high-dose oleuropein group (24 mg/kg/day oleuropein, HDO group, n = 8). Periodontitis was induced via ligatures. Study period was 14 days, and animals were sacrificed at end of this period. Mandibles were examined via a stereomicroscope and underwent histological procedures. Osteoblast, tartrate-resistant acid phosphatase (TRAP)-positive osteoclast, and inflammatory cell counts were determined in hematoxylin-eosin stained sections. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-4, the cluster of differentiation (CD)-68, cysteine-aspartic proteases-3 (Caspase 3), and B-cell lymphoma-2 (Bcl-2) expressions were evaluated via immunohistochemistry. RESULTS Periodontitis group had highest alveolar bone loss, and these levels significantly decreased in LDO and HDO groups. Both 12 and 24 mg/kg oleuropein groups significantly increased osteoblast cell counts and decreased TRAP-positive osteoclast and inflammatory cell counts. BMP-4 and bcl-2 expressions were elevated in oleuropein groups while caspase-3 expressions decreased. iNOS and CD68 were higher in periodontitis group compared to control group, but there was no significant difference between other groups. CONCLUSION Oleuropein successfully decreased alveolar bone loss as a result of decreased osteoclastic activity, inflammation, and apoptosis and increased osteoblastic activity.
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Affiliation(s)
- Mehmet Murat Taskan
- Department of Periodontology, Faculty of Dentistry, Tokat Gaziosmanpasa University, Tokat, Turkey
| | - Hatice Balci Yuce
- Department of Periodontology, Faculty of Dentistry, Tokat Gaziosmanpasa University, Tokat, Turkey
| | - Ozkan Karatas
- Department of Periodontology, Faculty of Dentistry, Tokat Gaziosmanpasa University, Tokat, Turkey
| | - Fikret Gevrek
- Department of Histology and Embryology, Faculty of Medicine, Tokat Gaziosmanpasa University, Tokat, Turkey
| | - Hülya Toker
- Department of Periodontology, Gulhane Faculty of Dentistry, University of Medical Sciences, Ankara, Turkey
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Yu X, Liu H, Li C, Du Y, Du Y, Zhang S. Periodontal ligament-associated protein-1 gets involved in the development of osseous eruption canal. J Mol Histol 2018; 50:35-42. [PMID: 30511172 DOI: 10.1007/s10735-018-9805-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 11/28/2018] [Indexed: 01/09/2023]
Abstract
Osseous eruption is an important stage of tooth eruption process. The role of periodontal ligament-associated protein-1 (PLAP-1/asporin) in the development of osseous eruption canal remain undefined and were the focus of this study. C57BL/6 mice at postnatal days P11-13 and P 15-16 were chosen. The development of osseous eruption canal of lower first molar was observed and osteoclasts were detected by staining for tartrate-resistant acid phosphatase (TRAP). PLAP-1 expression in the process of osseous eruption (OE, P11-13) and post- osseous eruption (P-OE, P15-16) was assessed by immunohistochemistry, immunofluorescence and western blotting. Receptor activator of NF-κB ligand (RANKL) distribution in the process was also assessed by immunohistochemistry. A double immunofluorescence stain was used to reveal PLAP-1 in association with CD68 (osteoclast maker). Fresh occlusal tissues of erupting lower first molars at OE and P-OE were separated to detected RANKL/OPG ratio by western blotting to elucidate related mechanisms. At osseous eruption (OE), osseous and mucosal tissues could be observed on the occlusal side of lower first molar. Osseous eruption canal was developing. Many osteoclasts were found around occlusal alveolar bone in the development of osseous eruption canal. At post- osseous eruption (P-OE), osseous eruption canal had been built, only mucosal tissues were observed, and few osteoclasts were detected. More PLAP-1 expression was detected at OE, compared with that at P-OE. Similar distributions of PLAP-1 and RANKL in occlusal bone tissues of erupting lower first molars were detected at OE. Colocalization of PLAP-1 and CD68 revealed the positive relationship between PLAP-1 and osteoclasts in the development of osseous eruption canal. PLAP-1 positively correlated with RANKL and CD68+ osteoclasts, and areas of bone resorption. Higher RANKL/OPG ratio was detected at OE, compared with that at P-OE. PLAP-1 gets involved in the development of osseous eruption canal.
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Affiliation(s)
- Xijiao Yu
- Department of Oral Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, People's Republic of China
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, 250001, Shandong, People's Republic of China
| | - Hongmei Liu
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, 250001, Shandong, People's Republic of China
| | - Chong Li
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, 250001, Shandong, People's Republic of China
| | - Yanmei Du
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, 250001, Shandong, People's Republic of China
| | - Yi Du
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, 250001, Shandong, People's Republic of China
| | - Shanyong Zhang
- Department of Oral Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, People's Republic of China.
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Yu X, Liu H, Liu S, Chen X, Zhao X, Du Y, Li S. Periodontal ligament-associated protein-1 gets involved in experimental periodontitis. J Periodontal Res 2018; 54:180-189. [PMID: 30298589 DOI: 10.1111/jre.12618] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 09/02/2018] [Accepted: 09/08/2018] [Indexed: 01/27/2023]
Abstract
BACKGROUND AND OBJECTIVE Periodontal ligament-associated protein-1 (PLAP-1) is an important regulator of osteogenic differentiation of periodontal ligament cells and plays important role in the homeostasis of periodontal tissues. But the role of PLAP-1 in periodontitis is poorly understood. Expressions of PLAP-1 in experimental periodontitis are observed to elucidate whether PLAP-1 gets involved in the pathogenesis of periodontitis. MATERIAL AND METHODS Wistar rats were randomly allocated to two groups (n = 6/group): Ligation group and Control group. PLAP-1 expression in experimental periodontitis was assessed by immunohistochemistry and collagen fibers in periodontal ligament were observed using picrosirius red staining. Expressions of PLAP-1 and CD68 in periodontitis were colocalized by double-labelled immunofluorescence. To further examine the relationship between PLAP-1 and osteoclastogenesis in experimental periodontitis, acute periodontal inflammatory infiltration and alveolar bone destruction were induced by administering ligated rats with 10 ng/mL tumor necrosis factor alpha (TNF-α; ligation + TNF-α group, n = 6). Alveolar bone loss was observed by micro-computed tomography (Micro-CT), and osteoclasts were identified by tartrate-resistant acid phosphatase staining (TRAP). Expressions of PLAP-1 in TNF-α stimulated human periodontal ligament cells were also detected at 24 and 48 hours by western blotting. RESULTS PLAP-1 expression levels in periodontal ligament cells and collagen fibers were lower in the ligation group,compared with the control group. Similarly, TNF-α decreased PLAP-1 expression in human periodontal ligament cells in vitro. Degradation or destruction of collagen fibers accompanied the reduced PLAP-1 expression in the periodontal ligament in the ligation group. Colocalization of PLAP-1 and CD68 revealed the positive relationship between PLAP-1 and CD68+ infiltrating cells in periodontitis. More PLAP-1-positive inflammatory cells were found in the ligation + TNF-α group, compared with the ligation + saline group. CONCLUSION PLAP-1-positive inflammatory cells are involved in the pathogenesis of periodontitis. An increase in PLAP-1-positive inflammatory cell number contributes periodontal inflammation and alveolar bone loss.
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Affiliation(s)
- Xijiao Yu
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, China.,Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School and Hospital of Stomatology, Shandong University, Jinan, China
| | - Hongmei Liu
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, China
| | - Shuang Liu
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School and Hospital of Stomatology, Shandong University, Jinan, China
| | - Xue Chen
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School and Hospital of Stomatology, Shandong University, Jinan, China
| | - Xinyu Zhao
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School and Hospital of Stomatology, Shandong University, Jinan, China
| | - Yi Du
- Department of Endodontics, Jinan Stomatological Hospital, Jinan, China
| | - Shu Li
- Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School and Hospital of Stomatology, Shandong University, Jinan, China
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