1
|
Wang W, Sun DF, Cui HX, Zhang WL. The nano-artificial periosteum made of PCL/MgO/AS-IV enhances MC3T3-E1 cell osteogenic differentiation and promotes bone defect repair via the EphB4/EphrinB2 signaling pathway. Heliyon 2024; 10:e32036. [PMID: 38882277 PMCID: PMC11176840 DOI: 10.1016/j.heliyon.2024.e32036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 05/03/2024] [Accepted: 05/27/2024] [Indexed: 06/18/2024] Open
Abstract
Bone regeneration plays a pivotal role in periodontal tissue repair. With advancements in biotechnology materials, the utilization of nanotechnology offers a reliable platform for bone restoration in periodontitis. In this study, we successfully established a long-term bacterial infection model using Porphyromonas gingivalis (P. gingivalis) with MOI = 50. CCK-8 and ROS immunofluorescence results demonstrated that the combined effect of Mg2+ and AS-IV significantly enhanced cell proliferation and effectively suppressed the inflammatory response during bacterial infection. Alkaline phosphatase and alizarin red staining revealed that the synergistic action of Mg2+ and AS-IV notably promoted osteogenic differentiation of MC3T3-E1 cells under P. gingivalis-infected conditions. Considering the properties of these two biomaterials, we fabricated polycaprolactone (PCL) artificial periosteum loaded with MgO and AS-IV using an electrostatic spinning technique. The findings indicated that PCL/MgO/AS-IV artificial periosteum exhibited excellent biocompatibility and hydrophilicity, thereby substantially enhancing cellular adhesion to its surface as well as augmenting cellular value-added rate. Moreover, efficient drug release from the PCL/MgO/AS-IV artificial bone membrane conferred remarkable antimicrobial activity along with in vitro osteogenic potentiality. The in vivo experiments conducted on animals further substantiated the exceptional properties exhibited by PCL/MgO/AS-IV artificial periosteum in bone defect repair. Additionally, it was observed that PCL/MgO/AS-IV artificial periosteum could modulate EphB4-EphrinB2 signaling to enhance osteogenic differentiation under P.gingivalis-infected conditions.This exciting outcome suggests that PCL/MgO/AS-IV artificial periosteum holds great promise as a biomaterial for treating periodontal bone loss.
Collapse
Affiliation(s)
- Wei Wang
- North Jiangsu Health Management Center of Zhongshan Hospital Affiliated to Fudan University, Yancheng, 224100, China
| | - Dan-Fang Sun
- Jinzhou Medical University, Jinzhou, 121000, China
| | - Hui-Xia Cui
- The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), 241004, Wuhu, China
| | - Wen-Lu Zhang
- The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), 241004, Wuhu, China
| |
Collapse
|
2
|
Reddi D, Belibasakis GN. Transcriptional profiling of bone marrow stromal cells in response to Porphyromonas gingivalis secreted products. PLoS One 2012; 7:e43899. [PMID: 22937121 PMCID: PMC3427182 DOI: 10.1371/journal.pone.0043899] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 07/30/2012] [Indexed: 12/18/2022] Open
Abstract
Periodontitis is an infectious inflammatory disease that destroys the tooth-supporting (periodontal) tissues. Porphyromonas gingivalis is an oral pathogen highly implicated in the pathogenesis of this disease. It can exert its effects to a number of cells, including osteogenic bone marrow stromal cells which are important for homeostastic capacity of the tissues. By employing gene microarray technology, this study aimed to describe the overall transcriptional events (>2-fold regulation) elicited by P. gingivalis secreted products in bone marrow stromal cells, and to dissect further the categories of genes involved in bone metabolism, inflammatory and immune responses. After 6 h of challenge with P. gingivalis, 271 genes were up-regulated whereas 209 genes were down-regulated, whereas after 24 h, these numbers were 259 and 109, respectively. The early (6 h) response was characterised by regulation of genes associated with inhibition of cell cycle, induction of apoptosis and loss of structural integrity, whereas the late (24 h) response was characterised by induction of chemokines, cytokines and their associated intracellular pathways (such as NF-κB), mediators of connective tissue and bone destruction, and suppression of regulators of osteogenic differentiation. The most strongly up-regulated genes were lipocalin 2 (LCN2) and serum amyloid A3 (SAA3), both encoding for proteins of the acute phase inflammatory response. Collectively, these transcriptional changes elicited by P. gingivalis denote that the fundamental cellular functions are hindered, and that the cells acquire a phenotype commensurate with propagated innate immune response and inflammatory-mediated tissue destruction. In conclusion, the global transcriptional profile of bone marrow stromal cells in response to P. gingivalis is marked by deregulated homeostatic functions, with implications in the pathogenesis of periodontitis.
Collapse
Affiliation(s)
- Durga Reddi
- Centre for Adult Oral Health, Barts and the London Institute of Dentistry, Queen Mary University of London, London, United Kingdom
| | - Georgios N. Belibasakis
- Centre for Adult Oral Health, Barts and the London Institute of Dentistry, Queen Mary University of London, London, United Kingdom
- Oral Microbiology and Immunology, Institute of Oral Biology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland
- * E-mail:
| |
Collapse
|
3
|
Die L, Yan P, Jun Jiang Z, Min Hua T, Cai W, Xing L. Glycogen synthase kinase-3 beta inhibitor suppresses Porphyromonas gingivalis lipopolysaccharide-induced CD40 expression by inhibiting nuclear factor-kappa B activation in mouse osteoblasts. Mol Immunol 2012; 52:38-49. [PMID: 22580404 DOI: 10.1016/j.molimm.2012.04.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/28/2012] [Accepted: 04/16/2012] [Indexed: 12/25/2022]
Abstract
Bone-forming osteoblasts have been recently reported capable of expressing the critical co-stimulatory molecule CD40 upon exposure to bacterial infection, which supports the unappreciated role of osteoblasts in modulating bone inflammation. Recent studies highlight the anti-inflammatory potential of glycogen synthase kinase-3β (GSK-3β) inhibitors; however, their effect on osteoblasts remains largely unclear. In the present study, we showed that treatment with SB216763, a highly specific GSK-3β inhibitor, resulted in a dose-dependent decrease in the mRNA and protein expression of CD40, as well as production of pro-inflammatory cytokines IL-6, TNF-α and IL-1β, in the Porphyromonas gingivalis-lipopolysaccharide (LPS)-stimulated murine osteoblastic-like MC3T3-E1 cells. Furthermore, inhibition of GSK-3β remarkably represses the LPS-induced activation of the nuclear factor kappa B (NF-κB) signaling pathway by suppressing IκBα phosphorylation, NF-κBp65 nuclear translocation, and NF-κBp65 DNA binding activity. Closer investigation by immunoprecipitation assay revealed that β-catenin can physically interact with NF-κBp65. The negative regulation effect of GSK-3β inhibitor on CD40 expression is mediated through β-catenin, for siRNA of β-catenin attenuated the GSK-3β inhibitor-induced repression of NF-κB activation and, consequently, the expression of CD40 and production of pro-inflammatory cytokines in LPS-stimulated MC3T3-E1 cells. Thus our results elucidate the molecular mechanisms whereby GSK-3β inhibitor prevents the LPS-induced CD40 expression on osteoblasts and provide supportive evidence of the potential role of GSK-3β inhibitors in suppressing the immune function of osteoblasts in inflammatory bone diseases.
Collapse
Affiliation(s)
- Liu Die
- Sichuan University, State Key Laboratory of Oral Disease, West China College of Stomatology, 14 Renminnan Road, Chengdu 610041, Sichuan, China.
| | | | | | | | | | | |
Collapse
|
4
|
Zhang W, Ju J, Rigney T, Tribble GD. Fimbriae of Porphyromonas gingivalis are important for initial invasion of osteoblasts, but not for inhibition of their differentiation and mineralization. J Periodontol 2010; 82:909-16. [PMID: 21189086 DOI: 10.1902/jop.2010.100501] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Porphyromonas gingivalis is etiologically associated with chronic periodontitis. The major fimbriae of this periodontal pathogen mediate binding to host gingival epithelial cells and fibroblasts, a critical function in the initiation of periodontitis. However, the role of fimbriae in P. gingivalis-osteoblast interactions remains unknown. In the present study, the involvement of major fimbriae in the initial and long-term interactions between P. gingivalis and osteoblasts is investigated. METHODS Primary mouse calvarial osteoblast cultures were established and inoculated with P. gingivalis ATCC 33277 or YPF1, a major fimbriae-deficient mutant of P. gingivalis. Confocal microscopy images were acquired to assess bacterial invasion. DNA content measurement, real-time polymerase chain reaction, and alizarin red S staining and calcium content analysis were used to study the impact of bacteria on the proliferation, differentiation, and mineralization of osteoblasts, respectively. RESULTS Compared to the parent strain, YPF1 was significantly reduced in invasion of osteoblasts after 3 hours interaction. However, extended culture of infected osteoblasts did not reveal significant differences in persistence between the two strains. Proliferation of osteoblasts was not affected by either strain, and differentiation and mineralization of osteoblasts were inhibited by both strains to comparable levels. CONCLUSION This study reveals that major fimbriae are involved in the initial invasion of osteoblasts by P. gingivalis, but are not essential for the subsequent inhibition of osteoblast differentiation and mineralization in long-term culture.
Collapse
Affiliation(s)
- Wenjian Zhang
- Department of Diagnostic Sciences, University of Texas Dental Branch at Houston, Houston, TX, USA.
| | | | | | | |
Collapse
|
5
|
Meka A, Bakthavatchalu V, Sathishkumar S, Lopez MC, Verma RK, Wallet SM, Bhattacharyya I, Boyce BF, Handfield M, Lamont RJ, Baker HV, Ebersole JL, Kesavalu L. Porphyromonas gingivalis infection-induced tissue and bone transcriptional profiles. Mol Oral Microbiol 2010; 25:61-74. [PMID: 20331794 DOI: 10.1111/j.2041-1014.2009.00555.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Porphyromonas gingivalis has been associated with subgingival biofilms in adult periodontitis. However, the molecular mechanisms of its contribution to chronic gingival inflammation and loss of periodontal structural integrity remain unclear. This investigation aimed to examine changes in the host transcriptional profiles during a P. gingivalis infection using a murine calvarial model of inflammation and bone resorption. P. gingivalis FDC 381 was injected into the subcutaneous soft tissue over the calvaria of BALB/c mice for 3 days, after which the soft tissues and calvarial bones were excised. RNA was isolated from infected soft tissues and calvarial bones and was analysed for transcript profiles using Murine GeneChip((R)) arrays to provide a molecular profile of the events that occur following infection of these tissues. After P. gingivalis infection, 6452 and 2341 probe sets in the infected soft tissues and calvarial bone, respectively, were differentially expressed (P </= 0.05). Biological pathways significantly impacted by P. gingivalis infection in tissues and calvarial bone included cell adhesion (immune system) molecules, Toll-like receptors, B-cell receptor signaling, transforming growth factor-beta cytokine family receptor signaling, and major histocompatibility complex class II antigen processing pathways resulting in proinflammatory, chemotactic effects, T-cell stimulation, and downregulation of antiviral and T-cell chemotactic effects. P. gingivalis-induced inflammation activated osteoclasts, leading to local bone resorption. This is the first in vivo evidence that localized P. gingivalis infection differentially induces transcription of a broad array of host genes, the profiles of which differed between inflamed soft tissues and calvarial bone.
Collapse
Affiliation(s)
- A Meka
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL 32610, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Zhang W, Swearingen EB, Ju J, Rigney T, Tribble GD. Porphyromonas gingivalis invades osteoblasts and inhibits bone formation. Microbes Infect 2010; 12:838-45. [PMID: 20538069 DOI: 10.1016/j.micinf.2010.05.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 05/28/2010] [Indexed: 11/18/2022]
Abstract
Porphyromonas gingivalis is etiologically associated with adult periodontitis, but it is unclear how P. gingivalis long-term interactions with bone cells contribute to this disease. This study investigates P. gingivalis interactions with osteoblasts over an extended time course. A primary mouse calvarial osteoblast culture was established and inoculated with P. gingivalis 33277 repeatedly every other day for up to four weeks. Invasion of osteoblasts by P. gingivalis, and the resulting effects on the proliferation, differentiation, and mineralization of osteoblasts were evaluated. P. gingivalis was found to invade osteoblasts in a dose-dependent manner, and repetitive inoculation increased the percentage of osteoblasts with internalized P. gingivalis. P. gingivalis did not affect osteoblast proliferation, but inhibited their differentiation and mineralization, partially via an inhibition of the differentiation regulatory transcription factors Cbfa-1 and osterix. In conclusion, P. gingivalis invades osteoblasts and inhibits bone formation, which likely contributes to alveolar bone loss in chronic periodontitis.
Collapse
Affiliation(s)
- Wenjian Zhang
- Department of Diagnostic Sciences, University of Texas Dental Branch at Houston, Houston, TX 77030, USA.
| | | | | | | | | |
Collapse
|
7
|
Jiang Y, Abernathy JW, Peatman E, Liu H, Wang S, Xu DH, Kucuktas H, Klesius P, Liu Z. Identification and characterization of matrix metalloproteinase-13 sequence structure and expression during embryogenesis and infection in channel catfish (Ictalurus punctatus). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2010; 34:590-597. [PMID: 20060415 DOI: 10.1016/j.dci.2010.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 12/31/2009] [Accepted: 01/03/2010] [Indexed: 05/28/2023]
Abstract
Matrix metalloproteinase-13 (MMP-13), referred to as collagenase-3, is a proteolytic enzyme that plays a key role in degradation and remodelling of host extracellular matrix proteins. The objective of this study was to characterize the MMP-13 gene in channel catfish, and to determine its pattern of expression in various healthy tissues and during embryogenesis. Since MMP-13 has been shown to have importance in tissue remodelling and some pathological processes, we further studied its involvement in the defense responses of catfish after bacterial infection. The channel catfish MMP-13 cDNA contains an open reading frame of 1416bp encoding 471 amino acids. Using RT-PCR analysis, MMP-13 was widely expressed in various health tissues. Using quantitative real-time PCR analysis, expression of MMP-13 gene was up-regulated by bacterial infection. During normal embryological development, MMP-13 expression was slightly increased in the first day post-fertilization and sharply up-regulated from 1-day post-fertilization through hatching.
Collapse
Affiliation(s)
- Yanliang Jiang
- The Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures, Program of Cell and Molecular Biosciences, Aquatic Genomics Unit, Auburn University, Auburn, AL 36849, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Shi Y, Liu XF, Zhuang Y, Zhang JY, Liu T, Yin Z, Wu C, Mao XH, Jia KR, Wang FJ, Guo H, Flavell RA, Zhao Z, Liu KY, Xiao B, Guo Y, Zhang WJ, Zhou WY, Guo G, Zou QM. Helicobacter pylori-induced Th17 responses modulate Th1 cell responses, benefit bacterial growth, and contribute to pathology in mice. THE JOURNAL OF IMMUNOLOGY 2010; 184:5121-9. [PMID: 20351183 DOI: 10.4049/jimmunol.0901115] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CD4(+) T cell responses are critical for the pathogenesis of Helicobacter pylori infection. The present study evaluated the role of the Th17 subset in H. pylori infection. H. pylori infection induced significant expression of IL-17 and IFN-gamma in mouse gastric tissue. IL-23 and IL-12 were increased in the gastric tissue and in H. pylori-stimulated macrophages. Cell responses were examined by intracellular staining for IFN-gamma, IL-4, and IL-17. Mice infected with H. pylori developed a mixed Th17/Th1 response; Th17 responses preceded Th1 responses. Treatment of mice with an anti-IL-17 Ab but not a control Ab significantly reduced the H. pylori burden and inflammation in the stomach. H. pylori colonization and gastric inflammation were also lower in IL-17(-/-) mice. Furthermore, administration of recombinant adenovirus encoding mouse IL-17 increased both H. pylori load and inflammation. Further analysis showed that the Th1 cell responses to H. pylori were downregulated when IL-17 is deficient. These results together suggest that H. pylori infection induces a mixed Th17/Th1 cell response and the Th17/IL-17 pathway modulates Th1 cell responses and contributes to pathology.
Collapse
Affiliation(s)
- Yun Shi
- Department of Clinical Microbiology and Immunology, Third Military Medical University, Chongqing 400038, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Fitzpatrick RE, Aprico A, Wijeyewickrema LC, Pagel CN, Wong DM, Potempa J, Mackie EJ, Pike RN. High molecular weight gingipains from Porphyromonas gingivalis induce cytokine responses from human macrophage-like cells via a nonproteolytic mechanism. J Innate Immun 2008; 1:109-17. [PMID: 20375569 DOI: 10.1159/000181145] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 10/08/2008] [Indexed: 11/19/2022] Open
Abstract
Periodontal disease is an oral inflammatory disease affecting the supporting structures of teeth. Porphyromonas gingivalis, a major pathogenic agent for the disease, expresses a number of virulence factors, including cysteine proteases called the gingipains. The arginine- and lysine-specific gingipains, HRgpA and Kgp, respectively, are expressed as high molecular weight forms containing both catalytic and adhesin subunits. We examined the expression pattern of cytokines and their receptors in differentiated macrophages following exposure to active and inactive forms of the gingipains, using a cDNA array, quantitative PCR and ELISA analysis. Amongst other pro-inflammatory cytokines, results from the cDNA array suggested that interleukin-1beta, granulocyte-macrophage colony stimulatory factor and interferon-gamma were upregulated after exposure of the macrophages to the gingipains. Quantitative PCR analysis substantiated these observations and indicated that active or inactive forms of the high molecular weight gingipains were able to upregulate expression of transcripts for these cytokines. The strongly enhanced production of interleukin-1beta and granulocyte-macrophage colony stimulatory factor by differentiated macrophages in response to active or inactive forms of the high molecular weight gingipains was confirmed at the protein level by ELISA analysis. The results indicate that the adhesin subunits of the gingipains mediate strong upregulation of the expression of pro-inflammatory cytokines in macrophages.
Collapse
Affiliation(s)
- Rebecca E Fitzpatrick
- Cooperative Research Centre for Oral Health Sciences, Monash University, Clayton, Vic., Australia
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Kato T, Tsuda T, Inaba H, Kawai S, Okahashi N, Shibata Y, Abiko Y, Amano A. Porphyromonas gingivalis gingipains cause G(1) arrest in osteoblastic/stromal cells. ACTA ACUST UNITED AC 2008; 23:158-64. [PMID: 18279184 DOI: 10.1111/j.1399-302x.2007.00405.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The program for mammalian cell growth and division consists of four successive phases; G(1), S, G(2), and M. Porphyromonas gingivalis may manipulate the host cell cycle to benefit bacterial virulence expression, which likely causes the cell and tissue tropism observed in chronic periodontal infections. We examined P. gingivalis for its effects on cell-cycle modulation in mouse ST2 osteoblastic/stromal cells. METHODS Synchronized ST2 cells were infected with P. gingivalis ATCC33277 (wild-type, WT), gingipain-mutants [KDP136 (DeltargpADeltargpBDeltakgp), KDP129 (DeltargpADeltargpB), and KDP133 (Deltakgp)], and a fimbria-deficient mutant (KDP150) for 24 h, then the cell cycle was evaluated using flow cytometry. Cell-cycle-related molecule expression was examined with a microarray, as well as with quantitative real-time polymerase chain reaction and Western blotting assays. RESULTS Both the WT and KDP150 strains significantly inhibited cellular proliferation and arrested the cell cycle in the G(0)/G(1) phase, while the expression levels of the cell-cycle regulatory molecules cyclin D and cyclin E were also decreased. In contrast, KDP136 did not show any effects. G(1) arrest was also clearly induced by KDP129 and KDP133, with KDP129 being more effective. CONCLUSION The present findings suggest that P. gingivalis gingipains reduce cyclin expression and cause early G(1) arrest, leading to the inhibition of cellular proliferation.
Collapse
Affiliation(s)
- T Kato
- Department of Oral Frontier Biology, Osaka University Graduate School of Dentistry, Suita-Osaka, Japan
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Ohno T, Okahashi N, Morisaki I, Amano A. Signaling pathways in osteoblast proinflammatory responses to infection by Porphyromonas gingivalis. ACTA ACUST UNITED AC 2008; 23:96-104. [DOI: 10.1111/j.1399-302x.2007.00393.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
12
|
Yuan L, Rodrigues PH, Bélanger M, Dunn W, Progulske-Fox A. The Porphyromonas gingivalis clpB gene is involved in cellular invasion in vitro and virulence in vivo. ACTA ACUST UNITED AC 2007; 51:388-98. [PMID: 17854400 DOI: 10.1111/j.1574-695x.2007.00326.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
ClpB, a component of stress response in microorganisms, serves as a chaperone, preventing protein aggregation and assisting in the refolding of denatured proteins. A clpB mutant of Porphyromonas gingivalis W83 demonstrated increased sensitivity to heat stress, but not to hydrogen peroxide and extreme pHs. In KB cells, human coronary artery endothelial (HCAE) cells and gingival epithelial cells, the clpB mutant exhibited significantly decreased invasion suggesting that the ClpB protein is involved in cellular invasion. Transmission electron microscopic analysis showed that the clpB mutant was more susceptible to intracellular killing than the wild-type strain in HCAE cells. The global genetic profile of the clpB mutant showed that 136 genes belonging to several different cellular function groups were differentially regulated, suggesting that ClpB is ultimately involved in the expression of multiple P. gingivalis genes. A competition assay in which a mixture of wild-type W83 and the clpB mutant were injected into mice demonstrated that the clpB mutant did not survive as well as the wild type. Additionally, mice treated with the clpB mutant alone survived significantly better than those treated with the wild-type strain. Collectively, these data suggest that ClpB, either directly or indirectly, plays an important role in P. gingivalis virulence.
Collapse
Affiliation(s)
- Lihui Yuan
- Department of Oral Biology, Center for Molecular Microbiology, College of Dentistry, University of Florida, Gainesville, FL 32610-0424, USA
| | | | | | | | | |
Collapse
|