scholarly journals GDF15 Supports the Inflammatory Response of PdL Fibroblasts Stimulated by P. gingivalis LPS and Concurrent Compression

2021 ◽  
Vol 22 (24) ◽  
pp. 13608
Author(s):  
Albert Stemmler ◽  
Judit Symmank ◽  
Julia Steinmetz ◽  
Katrin von von Brandenstein ◽  
Christoph-Ludwig Hennig ◽  
...  

Periodontitis is characterized by bacterially induced inflammatory destruction of periodontal tissue. This also affects fibroblasts of the human periodontal ligaments (HPdLF), which play a coordinating role in force-induced tissue and alveolar bone remodeling. Excessive inflammation in the oral tissues has been observed with simultaneous stimulation by pathogens and mechanical forces. Recently, elevated levels of growth differentiation factor 15 (GDF15), an immuno-modulatory member of the transforming growth factor (TGFB) superfamily, were detected under periodontitis-like conditions and in force-stressed PdL cells. In view of the pleiotropic effects of GDF15 in various tissues, this study aims to investigate the role of GDF15 in P. gingivalis-related inflammation of HPdLF and its effect on the excessive inflammatory response to concurrent compressive stress. To this end, the expression and secretion of cytokines (IL6, IL8, COX2/PGE2, TNFα) and the activation of THP1 monocytic cells were analyzed in GDF15 siRNA-treated HPdLF stimulated with P. gingivalis lipopolysaccharides alone and in combination with compressive force. GDF15 knockdown significantly reduced cytokine levels and THP1 activation in LPS-stimulated HPdLF, which was less pronounced with additional compressive stress. Overall, our data suggest a pro-inflammatory role for GDF15 in periodontal disease and demonstrate that GDF15 partially modulates the force-induced excessive inflammatory response of PdLF under these conditions.

2009 ◽  
Vol 88 (8) ◽  
pp. 752-756 ◽  
Author(s):  
A. Miyagawa ◽  
M. Chiba ◽  
H. Hayashi ◽  
K. Igarashi

During orthodontic tooth movement, the activation of the vascular system in the compressed periodontal ligament (PDL) is an indispensable process in tissue remodeling. We hypothesized that compressive force would induce angiogenesis of PDL through the production of vascular endothelial growth factor (VEGF). We examined the localization of VEGF in rat periodontal tissues during experimental tooth movement in vivo, and the effects of continuous compressive force on VEGF production and angiogenic activity in human PDL cells in vitro. PDL cells adjacent to hyalinized tissue and alveolar bone on the compressive side showed marked VEGF immunoreactivity. VEGF mRNA expression and production in PDL cells increased, and conditioned medium stimulated tube formation. These results indicate that continuous compressive force enhances VEGF production and angiogenic activity in PDL cells, which may contribute to periodontal remodeling, including angiogenesis, during orthodontic tooth movement.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yukun Jiang ◽  
Yuzhe Guan ◽  
Yuanchen Lan ◽  
Shuo Chen ◽  
Tiancheng Li ◽  
...  

Orthodontic tooth movement (OTM) is a process depending on the remodeling of periodontal tissues surrounding the roots. Orthodontic forces trigger the conversion of mechanical stimuli into intercellular chemical signals within periodontal ligament (PDL) cells, activating alveolar bone remodeling, and thereby, initiating OTM. Recently, the mechanosensitive ion channel Piezo1 has been found to play pivotal roles in the different types of human cells by transforming external physical stimuli into intercellular chemical signals. However, the function of Piezo1 during the mechanotransduction process of PDL cells has rarely been reported. Herein, we established a rat OTM model to study the potential role of Piezo1 during the mechanotransduction process of PDL cells and investigate its effects on the tension side of alveolar bone remodeling. A total of 60 male Sprague-Dawley rats were randomly assigned into three groups: the OTM + inhibitor (INH) group, the OTM group, and the control (CON) group. Nickel-titanium orthodontic springs were applied to trigger tooth movement. Mice were sacrificed on days 0, 3, 7, and 14 after orthodontic movement for the radiographic, histological, immunohistochemical, and molecular biological analyses. Our results revealed that the Piezo1 channel was activated by orthodontic force and mainly expressed in the PDL cells during the whole tooth movement period. The activation of the Piezo1 channel was essential for maintaining the rate of orthodontic tooth movement and facilitation of new alveolar bone formation on the tension side. Reduced osteogenesis-associated transcription factors such as Runt-related transcription factor 2 (RUNX2), Osterix (OSX), and receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) ratio were examined when the function of Piezo1 was inhibited. In summary, Piezo1 plays a critical role in mediating both the osteogenesis and osteoclastic activities on the tension side during OTM.


2018 ◽  
Vol 97 (12) ◽  
pp. 1374-1382 ◽  
Author(s):  
N. Odagaki ◽  
Y. Ishihara ◽  
Z. Wang ◽  
E. Ei Hsu Hlaing ◽  
M. Nakamura ◽  
...  

Sclerostin (Scl) negatively regulates bone formation and favors bone resorption. Osteocytes, the cells responsible for mechanosensing, are known as the primary source of Scl and are a key regulator of bone remodeling through the induction of receptor activator of NF-κB ligand (RANKL). However, the spatiotemporal patterns of Scl in response to mechanical stimuli and their regulatory mechanisms remain unknown. We investigated the regulatory dynamics of the SOST/Scl expression generated by orthodontic tooth movement (OTM) in vivo and in vitro. In 8-wk-old male mice, coil springs were used to move the first molar mesially for 0, 1, 5, or 10 d. A regional histogram and the distribution patterns of the Scl expression showed that the Scl expression in the alveolar bone was increased on the compression side and peaked on day 5, with a gradual increase in the degree of significance. On day 10, the expression around the periodontal ligament (PDL)–alveolar bone boundary returned to the control level. Conversely, the expression of Scl on the tension side was only significantly decreased on day 1. Compressive force biphasically modulated the SOST/Scl expression in the isolated human PDL and thereby upregulated osteocytic SOST via paracrine activation in an osteocyte-PDL co-culture system designed to mimic OTM. This system did not affect the RANKL or OPG expression in osteocytes, suggesting that the bone resorption pathways are acted upon in a PDL-dependent and osteocyte-independent manner through RANKL/OPG signaling. Moreover, sclerostin neutralizing antibody significantly attenuated the upregulation of SOST that was induced by compressive force. In conclusion, our results provide evidence to support that factors secreted by the PDL, including SOST/Scl, control alveolar bone remodeling through osteocytic SOST/Scl in OTM.


2021 ◽  
Vol 22 (24) ◽  
pp. 13491
Author(s):  
Hideki Sugii ◽  
Mhd Safwan Albougha ◽  
Orie Adachi ◽  
Hiroka Tomita ◽  
Atsushi Tomokiyo ◽  
...  

Activin A, a member of transforming growth factor-β superfamily, is involved in the regulation of cellular differentiation and promotes tissue healing. Previously, we reported that expression of activin A was upregulated around the damaged periodontal tissue including periodontal ligament (PDL) tissue and alveolar bone, and activin A promoted PDL-related gene expression of human PDL cells (HPDLCs). However, little is known about the biological function of activin A in alveolar bone. Thus, this study analyzed activin A-induced biological functions in preosteoblasts (Saos2 cells). Activin A promoted osteoblastic differentiation of Saos2 cells. Activin receptor-like kinase (ALK) 1, an activin type I receptor, was more strongly expressed in Saos2 cells than in HPDLCs, and knockdown of ALK1 inhibited activin A-induced osteoblastic differentiation of Saos2 cells. Expression of ALK1 was upregulated in alveolar bone around damaged periodontal tissue when compared with a nondamaged site. Furthermore, activin A promoted phosphorylation of Smad1/5/9 during osteoblastic differentiation of Saos2 cells and knockdown of ALK1 inhibited activin A-induced phosphorylation of Smad1/5/9 in Saos2 cells. Collectively, these findings suggest that activin A promotes osteoblastic differentiation of preosteoblasts through the ALK1-Smad1/5/9 pathway and could be used as a therapeutic product for the healing of alveolar bone as well as PDL tissue.


2014 ◽  
Vol 93 (11) ◽  
pp. 1163-1169 ◽  
Author(s):  
H. Cao ◽  
X. Kou ◽  
R. Yang ◽  
D. Liu ◽  
X. Wang ◽  
...  

The sympathetic nervous system (SNS) regulates bone resorption through β-2 adrenergic receptor (Adrb2). In orthodontic tooth movement (OTM), mechanical force induces and regulates alveolar bone remodeling. Compressive force-associated osteoclast differentiation and alveolar bone resorption are the rate-limiting steps of tooth movement. However, whether mechanical force can activate Adrb2 and thus contribute to OTM remains unknown. In this study, orthodontic nickel-titanium springs were applied to the upper first molars of rats and Adrb1/2-/- mice to confirm the role of SNS and Adrb2 in OTM. The results showed that blockage of SNS activity in the jawbones of rats by means of superior cervical ganglion ectomy reduced OTM distance from 860 to 540 μm after 14 d of force application. In addition, the injection of nonselective Adrb2 agonist isoproterenol activated the downstream signaling of SNS to accelerate OTM from 300 to 540 μm after 7 d of force application. Adrb1/2-/- mice showed significantly reduced OTM distance (19.5 μm) compared with the wild-type mice (107.6 μm) after 7 d of force application. Histopathologic analysis showed that the number of Adrb2-positive cells increased in the compressive region of periodontal ligament after orthodontic force was applied on rats. Mechanistically, mechanical compressive force upregulated Adrb2 expression in primary-cultured human periodontal ligament cells (PDLCs) through the elevation of intracellular Ca2+ concentration. Activation of Adrb2 in PDLCs increased the RANKL/OPG ratio and promoted the peripheral blood mononuclear cell differentiation to osteoclasts in the cocultured system. Upregulation of Adrb2 in PDLCs promoted osteoclastogenesis, which accelerated OTM through Adrb2-enhanced bone resorption. In summary, this study suggests that mechanical force-induced Adrb2 activation in PDLCs contributes to SNS-regulated OTM.


2021 ◽  
pp. 002203452110199
Author(s):  
Y. Xie ◽  
Q. Tang ◽  
S. Yu ◽  
W. Zheng ◽  
G. Chen ◽  
...  

Orthodontic tooth movement (OTM) depends on periodontal ligament cells (PDLCs) sensing biomechanical stimuli and subsequently releasing signals to initiate alveolar bone remodeling. However, the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities are still unclear. This study demonstrates that the core circadian protein aryl hydrocarbon receptor nuclear translocator–like protein 1 (BMAL1) in PDLCs is highly involved in sensing and delivering biomechanical signals. Orthodontic force upregulates BMAL1 expression in periodontal tissues and cultured PDLCs in manners dependent on ERK (extracellular signal–regulated kinase) and AP1 (activator protein 1). Increased BMAL1 expression can enhance secretion of CCL2 (C-C motif chemokine 2) and RANKL (receptor activator of nuclear factor–κB ligand) in PDLCs, which subsequently promotes the recruitment of monocytes that differentiate into osteoclasts. The mechanistic delineation clarifies that AP1 induced by orthodontic force can directly interact with the BMAL1 promoter and activate gene transcription in PDLCs. Localized administration of the ERK phosphorylation inhibitor U0126 or the BMAL1 inhibitor GSK4112 suppressed ERK/AP1/BMAL1 signaling. These treatments dramatically reduced osteoclastic activity in the compression side of a rat orthodontic model, and the OTM rate was almost nonexistent. In summary, our results suggest that force-induced expression of BMAL1 in PDLCs is closely involved in controlling osteoclastic activities during OTM and plays a vital role in alveolar bone remodeling. It could be a useful therapeutic target for accelerating the OTM rate and controlling pathologic bone-remodeling activities.


Author(s):  
Dorota Ochijewicz ◽  
Mariusz Tomaniak ◽  
Grzegorz Opolski ◽  
Janusz Kochman

AbstractCardiovascular disease remains the leading cause of death and morbidity worldwide. Inflammation plays an important role in the development of atherosclerosis and is associated with adverse clinical outcomes in patients after percutaneous coronary interventions. Data on stent elements that lead to excessive inflammatory response, proper identification of high–risk patients, prevention and treatment targeting residual inflammatory risk are limited. This review aims to present the role of inflammation in the context of evolving stent technologies and appraise the potential imaging modalities in detection of inflammatory response and anti-inflammatory therapies.


2017 ◽  
Vol 52 (7) ◽  
pp. 680-689
Author(s):  
Sheng-Yu Lee ◽  
Tzu-Yun Wang ◽  
Shiou-Lan Chen ◽  
Yun-Hsuan Chang ◽  
Po-See Chen ◽  
...  

Objectives: We investigated the association of the aldehyde dehydrogenase 2 ( ALDH2) polymorphism (rs671), which is involved with the dopaminergic function, and with changes in cytokine levels and cognitive function, in a 12-week follow-up study in patients with bipolar disorder. Methods: Patients with a first diagnosis of bipolar disorder were recruited. Symptom severity and levels of plasma cytokines (tumor necrosis factor α, C-reactive protein, interleukin 6 and transforming growth factor β1) were examined during weeks 0, 1, 2, 4, 8 and 12. Neurocognitive function was evaluated at baseline and endpoint. The ALDH2 polymorphism genotype was determined. Results: A total of 541 patients with bipolar disorder were recruited, and 355 (65.6%) completed the 12-week follow-up. A multiple linear regression analysis showed a significant ( p = 0.000226) association between the ALDH2 polymorphism and changes in C-reactive protein levels. Different aspects of cognitive function improved in patients with different ALDH2 genotypes. Only patients with the ALDH2*1*1 genotype showed significant correlations between improvement of cognitive function and increased transforming growth factor -β1. Conclusion: The ALDH2 gene might influence changes in cytokine levels and cognitive performance in patients with bipolar disorder. Additionally, changes in cytokine levels and cognitive function were correlated only in patients with specific ALDH2 genotypes.


2016 ◽  
Vol 29 (4) ◽  
pp. 696-706 ◽  
Author(s):  
Jun Shi ◽  
Yu Liu ◽  
Shihai Yan ◽  
Daonan Yan

Allergic rhinitis (AR) is an inflammatory disease with a hypersensitivity response to environmental stimulus. The aim of this study was to evaluate the effect of Yiqi Wenyang Fang (YWF) on AR and investigate the underlying mechanism. A total of 48 female Sprague-Dawley rats were randomly divided into six groups (normal control, model control, YWF at low dose, YWF at median dose, YWF at high dose, and loratadine). Rats were injected with antigen for sensitization. Then, rats in the YWF groups were treated with different dose of YWF for 28 days. Loratadine was used as a positive control. Number of sneezes, degree of runny nose, nasal rubbing movements, and tissue damage were scored. The protein and mRNA expression of Foxp3 were determined by western blot and real time-PCR analysis, respectively. Flow cytometry was used to detect the number of CD4+CD25+Foxp3+ Treg cells. The content of interleukin (IL)-10, transforming growth factor β1 (TGF-β1), IL-13, and IL-4 in the serum were detected by enzyme-linked immunosorbent assay (ELISA). Scores of symptoms were significantly reduced and nasal mucosa damage was alleviated after YWF administration. YWF increased the expression of Foxp3, IL-10, TGF-β1, and number of CD4+CD25+Foxp3+ Treg cells which were reduced by antigen injection. The expression levels of IL-13 and IL-4 were increased after antigen administration while decreased after YWF treatment. YWF may ameliorate AR through inhibiting inflammatory response and promoting Foxp3 expression.


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