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Li N, He F, Shang Y. Growth differentiation factor 15 protects the airway by inhibiting cell pyroptosis in obese asthmatic mice through the phosphoinositide 3-kinase/AKT pathway. Int Immunopharmacol 2023; 119:110149. [PMID: 37058747 DOI: 10.1016/j.intimp.2023.110149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/11/2023] [Accepted: 03/31/2023] [Indexed: 04/16/2023]
Abstract
Obese asthma is a form of refractory asthma with inflammation as the underlying mechanism. The specific mechanism of action of anti-inflammatory growth differentiation factor 15 (GDF15) in obese asthma is unclear. The purpose of this study was to explore the effect of GDF15 on cell pyroptosis in obese asthma and to determine its mechanism of airway protection. Male C57BL6/J mice were fed with a high-fat diet, sensitized, and challenged with ovalbumin. Recombinant human (rh)GDF15 was administered 1 h before the challenge. GDF15 treatment significantly reduced airway inflammatory cell infiltration, mucus hypersecretion and airway resistant, and decreased cell counts and inflammatory factors in bronchoalveolar lavage fluid. Serum inflammatory factors decreased, and the increased levels of NLR family pyrin domain containing 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and gasdermin-D (GSDMD-N) in obese asthmatic mice were inhibited. Furthermore, the suppressed phosphoinositide 3-kinase (PI3K)/AKT signal pathway was activated after rhGDF15 treatment. The same result was obtained by overexpression of GDF15 in human bronchial epithelial cells induced by lipopolysaccharide (LPS) in vitro, and the effect of GDF15 was reversed after the application of a PI3K pathway inhibitor. Thus, GDF15 could protect the airway by inhibiting cell pyroptosis in obese asthmatic mice through the PI3K/AKT signaling pathway.
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Affiliation(s)
- Na Li
- Department of Pediatrics, Shengjing Hospital of China Medical University, No. 36, Sanhao Street, Heping District, Shenyang 110004, Liaoning Province, China; Department of Pediatrics, The Second Hospital of Dalian Medical University, No. 467, Zhongshan Road, Shahekou District, Dalian 116021, Liaoning Province, China
| | - Fanghan He
- Department of Pediatrics, Xi'an Children's Hospital, No. 69, Xi Ju Yuan Xiang, Lianhu District, Xi'an 710002, Shanxi Province, China
| | - Yunxiao Shang
- Department of Pediatrics, Shengjing Hospital of China Medical University, No. 36, Sanhao Street, Heping District, Shenyang 110004, Liaoning Province, China.
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2
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Mata-Martínez P, Bergón-Gutiérrez M, del Fresno C. Dectin-1 Signaling Update: New Perspectives for Trained Immunity. Front Immunol 2022; 13:812148. [PMID: 35237264 PMCID: PMC8882614 DOI: 10.3389/fimmu.2022.812148] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/20/2022] [Indexed: 12/12/2022] Open
Abstract
The C-type lectin receptor Dectin-1 was originally described as the β-glucan receptor expressed in myeloid cells, with crucial functions in antifungal responses. However, over time, different ligands both of microbial-derived and endogenous origin have been shown to be recognized by Dectin-1. The outcomes of this recognition are diverse, including pro-inflammatory responses such as cytokine production, reactive oxygen species generation and phagocytosis. Nonetheless, tolerant responses have been also attributed to Dectin-1, depending on the specific ligand engaged. Dectin-1 recognition of their ligands triggers a plethora of downstream signaling pathways, with complex interrelationships. These signaling routes can be modulated by diverse factors such as phosphatases or tetraspanins, resulting either in pro-inflammatory or regulatory responses. Since its first depiction, Dectin-1 has recently gained a renewed attention due to its role in the induction of trained immunity. This process of long-term memory of innate immune cells can be triggered by β-glucans, and Dectin-1 is crucial for its initiation. The main signaling pathways involved in this process have been described, although the understanding of the above-mentioned complexity in the β-glucan-induced trained immunity is still scarce. In here, we have reviewed and updated all these factors related to the biology of Dectin-1, highlighting the gaps that deserve further research. We believe on the relevance to fully understand how this receptor works, and therefore, how we could harness it in different pathological conditions as diverse as fungal infections, autoimmunity, or cancer.
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Affiliation(s)
| | | | - Carlos del Fresno
- Immune response and Immunomodulation Group, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
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3
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He X, Howard BA, Liu Y, Neumann AK, Li L, Menon N, Roach T, Kale SD, Samuels DC, Li H, Kite T, Kita H, Hu TY, Luo M, Jones CN, Okaa UJ, Squillace DL, Klein BS, Lawrence CB. LYSMD3: A mammalian pattern recognition receptor for chitin. Cell Rep 2021; 36:109392. [PMID: 34289364 PMCID: PMC8344708 DOI: 10.1016/j.celrep.2021.109392] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/28/2021] [Accepted: 06/22/2021] [Indexed: 02/07/2023] Open
Abstract
Chitin, a major component of fungal cell walls, has been associated with allergic disorders such as asthma. However, it is unclear how mammals recognize chitin and the principal receptor(s) on epithelial cells that sense chitin remain to be determined. In this study, we show that LYSMD3 is expressed on the surface of human airway epithelial cells and demonstrate that LYSMD3 is able to bind chitin, as well as β-glucan, on the cell walls of fungi. Knockdown or knockout of LYSMD3 also sharply blunts the production of inflammatory cytokines by epithelial cells in response to chitin and fungal spores. Competitive inhibition of the LYSMD3 ectodomain by soluble LYSMD3 protein, multiple ligands, or antibody against LYSMD3 also blocks chitin signaling. Our study reveals LYSMD3 as a mammalian pattern recognition receptor (PRR) for chitin and establishes its role in epithelial cell inflammatory responses to chitin and fungi.
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Affiliation(s)
- Xin He
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Brad A Howard
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Yang Liu
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA; Cancer Institute and Hospital, Tianjin Medical University, Tianjin 300060, China
| | - Aaron K Neumann
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Nidhi Menon
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061, USA
| | - Tiffany Roach
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Shiv D Kale
- Nutritional Immunology and Molecular Medicine Institute, Blacksburg, VA 24060, USA
| | - David C Samuels
- Department of Molecular Physiology and Biophysics, Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Hongyan Li
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Trenton Kite
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Hirohito Kita
- Department of Immunology, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
| | - Tony Y Hu
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Mengyao Luo
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Caroline N Jones
- Department of Bioengineering, University of Texas, Dallas, TX 75080, USA
| | - Uju Joy Okaa
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Diane L Squillace
- Department of Immunology, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
| | - Bruce S Klein
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA.
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4
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Lv L, Gu S, Jiang H, Yan R, Chen Y, Chen Y, Luo R, Huang C, Lu H, Zheng B, Zhang H, Xia J, Tang L, Sheng G, Li L. Gut mycobiota alterations in patients with COVID-19 and H1N1 infections and their associations with clinical features. Commun Biol 2021; 4:480. [PMID: 33850296 PMCID: PMC8044104 DOI: 10.1038/s42003-021-02036-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 03/24/2021] [Indexed: 02/06/2023] Open
Abstract
The relationship between gut microbes and COVID-19 or H1N1 infections is not fully understood. Here, we compared the gut mycobiota of 67 COVID-19 patients, 35 H1N1-infected patients and 48 healthy controls (HCs) using internal transcribed spacer (ITS) 3-ITS4 sequencing and analysed their associations with clinical features and the bacterial microbiota. Compared to HCs, the fungal burden was higher. Fungal mycobiota dysbiosis in both COVID-19 and H1N1-infected patients was mainly characterized by the depletion of fungi such as Aspergillus and Penicillium, but several fungi, including Candida glabrata, were enriched in H1N1-infected patients. The gut mycobiota profiles in COVID-19 patients with mild and severe symptoms were similar. Hospitalization had no apparent additional effects. In COVID-19 patients, Mucoromycota was positively correlated with Fusicatenibacter, Aspergillus niger was positively correlated with diarrhoea, and Penicillium citrinum was negatively correlated with C-reactive protein (CRP). In H1N1-infected patients, Aspergillus penicilloides was positively correlated with Lachnospiraceae members, Aspergillus was positively correlated with CRP, and Mucoromycota was negatively correlated with procalcitonin. Therefore, gut mycobiota dysbiosis occurs in both COVID-19 patients and H1N1-infected patients and does not improve until the patients are discharged and no longer require medical attention. Lv et al. associate the gut mycobiota with clinical features and the bacterial microbiota by comparing COVID-19 patients to those infected with H1N1 and healthy controls. They find that gut mycobiota dysbiosis occurs in both COVID-19 patients and those infected with H1N1 and that it does not improve until patients no longer require medical attention, providing insights into a better healthcare guideline.
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Affiliation(s)
- Longxian Lv
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Silan Gu
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Huiyong Jiang
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Ren Yan
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Yanfei Chen
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Yunbo Chen
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Rui Luo
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Chenjie Huang
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Haifeng Lu
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Beiwen Zheng
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Hua Zhang
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Jiafeng Xia
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Lingling Tang
- Department of Infectious Diseases, Shulan (Hangzhou) Hospital, Affiliated to Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China
| | - Guoping Sheng
- Department of Infectious Diseases, Shulan (Hangzhou) Hospital, Affiliated to Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China
| | - Lanjuan Li
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
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5
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Bissonnette EY, Lauzon-Joset JF, Debley JS, Ziegler SF. Cross-Talk Between Alveolar Macrophages and Lung Epithelial Cells is Essential to Maintain Lung Homeostasis. Front Immunol 2020; 11:583042. [PMID: 33178214 PMCID: PMC7593577 DOI: 10.3389/fimmu.2020.583042] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/30/2020] [Indexed: 12/22/2022] Open
Abstract
The main function of the lung is to perform gas exchange while maintaining lung homeostasis despite environmental pathogenic and non-pathogenic elements contained in inhaled air. Resident cells must keep lung homeostasis and eliminate pathogens by inducing protective immune response and silently remove innocuous particles. Which lung cell type is crucial for this function is still subject to debate, with reports favoring either alveolar macrophages (AMs) or lung epithelial cells (ECs) including airway and alveolar ECs. AMs are the main immune cells in the lung in steady-state and their function is mainly to dampen inflammatory responses. In addition, they phagocytose inhaled particles and apoptotic cells and can initiate and resolve inflammatory responses to pathogens. Although AMs release a plethora of mediators that modulate immune responses, ECs also play an essential role as they are more than just a physical barrier. They produce anti-microbial peptides and can secrete a variety of mediators that can modulate immune responses and AM functions. Furthermore, ECs can maintain AMs in a quiescent state by expressing anti-inflammatory membrane proteins such as CD200. Thus, AMs and ECs are both very important to maintain lung homeostasis and have to coordinate their action to protect the organism against infection. Thus, AMs and lung ECs communicate with each other using different mechanisms including mediators, membrane glycoproteins and their receptors, gap junction channels, and extracellular vesicles. This review will revisit characteristics and functions of AMs and lung ECs as well as different communication mechanisms these cells utilize to maintain lung immune balance and response to pathogens. A better understanding of the cross-talk between AMs and lung ECs may help develop new therapeutic strategies for lung pathogenesis.
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Affiliation(s)
- Elyse Y Bissonnette
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval, Quebec City, QC, Canada
| | - Jean-François Lauzon-Joset
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval, Quebec City, QC, Canada
| | - Jason S Debley
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, United States
| | - Steven F Ziegler
- Department of Immunology, Benaroya Research Institute, University of Washington School of Medicine, Seattle, WA, United States
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6
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Zhang M, Jin X, Yang YF. β-Glucan from Saccharomyces cerevisiae induces SBD-1 production in ovine ruminal epithelial cells via the Dectin-1–Syk–NF-κB signaling pathway. Cell Signal 2019; 53:304-315. [DOI: 10.1016/j.cellsig.2018.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 12/26/2022]
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7
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Goyal S, Castrillón-Betancur JC, Klaile E, Slevogt H. The Interaction of Human Pathogenic Fungi With C-Type Lectin Receptors. Front Immunol 2018; 9:1261. [PMID: 29915598 PMCID: PMC5994417 DOI: 10.3389/fimmu.2018.01261] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/18/2018] [Indexed: 01/19/2023] Open
Abstract
Fungi, usually present as commensals, are a major cause of opportunistic infections in immunocompromised patients. Such infections, if not diagnosed or treated properly, can prove fatal. However, in most cases healthy individuals are able to avert the fungal attacks by mounting proper antifungal immune responses. Among the pattern recognition receptors (PRRs), C-type lectin receptors (CLRs) are the major players in antifungal immunity. CLRs can recognize carbohydrate ligands, such as β-glucans and mannans, which are mainly found on fungal cell surfaces. They induce proinflammatory immune reactions, including phagocytosis, oxidative burst, cytokine, and chemokine production from innate effector cells, as well as activation of adaptive immunity via Th17 responses. CLRs such as Dectin-1, Dectin-2, Mincle, mannose receptor (MR), and DC-SIGN can recognize many disease-causing fungi and also collaborate with each other as well as other PRRs in mounting a fungi-specific immune response. Mutations in these receptors affect the host response and have been linked to a higher risk in contracting fungal infections. This review focuses on how CLRs on various immune cells orchestrate the antifungal response and on the contribution of single nucleotide polymorphisms in these receptors toward the risk of developing such infections.
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Affiliation(s)
- Surabhi Goyal
- Institute for Microbiology and Hygiene, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Juan Camilo Castrillón-Betancur
- Septomics Research Center, Jena University Hospital, Jena, Germany.,International Leibniz Research School for Microbial and Biomolecular Interactions, Leibniz Institute for Natural Product Research and Infection Biology/Hans Knöll Institute, Jena, Germany
| | - Esther Klaile
- Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Hortense Slevogt
- Septomics Research Center, Jena University Hospital, Jena, Germany
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8
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Estrogen Effects on Wound Healing. Int J Mol Sci 2017; 18:ijms18112325. [PMID: 29099810 PMCID: PMC5713294 DOI: 10.3390/ijms18112325] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/30/2017] [Accepted: 11/02/2017] [Indexed: 02/07/2023] Open
Abstract
Wound healing is a physiological process, involving three successive and overlapping phases—hemostasis/inflammation, proliferation, and remodeling—to maintain the integrity of skin after trauma, either by accident or by procedure. Any disruption or unbalanced distribution of these processes might result in abnormal wound healing. Many molecular and clinical data support the effects of estrogen on normal skin homeostasis and wound healing. Estrogen deficiency, for example in postmenopausal women, is detrimental to wound healing processes, notably inflammation and re-granulation, while exogenous estrogen treatment may reverse these effects. Understanding the role of estrogen on skin might provide further opportunities to develop estrogen-related therapy for assistance in wound healing.
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9
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Jing S, Dapeng R, Shiguo Y, Jing L, Xiao Y, Qingyuan G, Xiangmin Q. [The role of extracellular signal regulated kinase 1/2 in mediating osteodifferentiation of human periodontal ligament cells induced by cyclic stretch]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2017; 35:520-526. [PMID: 29188650 PMCID: PMC7030397 DOI: 10.7518/hxkq.2017.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 12/09/2016] [Indexed: 11/21/2022]
Abstract
OBJECTIVE This study aimed to investigate the mechanism of cyclic stretch that promotesthe osteogenic differentiation of human periodontal ligament cells (hPDLCs) through the mediation of extracellular-signal-regulated kinase 1/2 (ERK1/2). METHODS hPDLCs were isolated through the explant method and cultured in vitro. hPDLCs were mechanically stimulated by a multi-channel cell-stress-loading system for 1, 3, 6, 12, and 24 h. The magnitude of stretch was 10% deformation, and the frequency was 0.5 Hz. Nonloaded cells were used as control group. ERK1/2 activation was blocked by U0126, a specific ERK1/2 pathway inhibitor. Additionally, hPDLCs were transfected with adenoviral vector encoding dominant negative ERK1/2 (DN-ERK1/2) to continuouslyinhibit ERK1/2 activation. The mRNA and protein levels of target geneswere detected through real-time polymerase chain reaction and Western blot. RESULTS Cyclic stretching promoted the expression of ERK1/2, osteocalcin (OCN) mRNA, and bone sialoprotein (BSP) mRNA. The expression of runt-related transcription factor (Runx) 2 protein and mRNA also increased at 3 and 6 h of cyclic stretching. The inhibition of ERK1/2 by U0126 and DN-ERK1/2 suppressed the expressionof Runx2 mRNA, OCN mRNA, BSP mRNA, Runx 2 protein, and p-ERK1/2 protein relative to that in stretched cells without the ERK1/2 inhibitor. CONCLUSIONS ERK1/2 is a critical molecule in the mediation ofthe osteogenic differentiation of hPDLCs under mechanical stimulation. ERK1/2 activation induced the elevation of Runx2 protein levels, which may be involved in the stretch-induced expressions of OCN and BSP.
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Affiliation(s)
- Song Jing
- Stomatology Hospital of Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan 250012, China
| | - Ren Dapeng
- Stomatology College of Qingdao University, Dept. of Orthodontics, The Affiliated Hospital of Qingdao University Medical College, Qingdao 266003, China
| | - Yan Shiguo
- Stomatology Hospital of Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan 250012, China
| | - Lan Jing
- Stomatology Hospital of Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan 250012, China
| | - Yuan Xiao
- Stomatology College of Qingdao University, Dept. of Orthodontics, The Affiliated Hospital of Qingdao University Medical College, Qingdao 266003, China; 3. Dept. of Orthodontics, Stomatological Center, The Affiliated Qingdao Municipal Hospital, Qingdao 266075, China
| | - Guo Qingyuan
- Dept. of Orthodontics, Stomatological Center, The Affiliated Qingdao Municipal Hospital, Qingdao 266075, China
| | - Qi Xiangmin
- Stomatology Hospital of Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan 250012, China
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