Elevated BMPR2 expression amplifies osteoblast differentiation in ankylosing spondylitis

Objective@#Bone morphogenetic protein receptor type 2 (BMPR2) has been associated with radiographic changes in ankylosing spondylitis (AS), but further characterization of the cellular signaling pathway in osteoprogenitor (OP) is not clearly understood.The aim of this study was to investigate the expression of BMPR2 and bone morphogenetic protein 2 (BMP2)-mediated responsibility in AS. @*Methods@#We collected 10 healthy control (HC) and 14 AS-OPs derived from facet joints. Subsequently, we then conducted RNA sequencing with two samples per group and selected BMP-related genes. Facet joint tissues and derived primary OPs were evaluated by validation of selected RNA sequencing data, immunohistochemistry, and comparison of osteogenic differentiation potential. @*Results@#Based on RNA-sequencing analysis, we found that BMPR2 expression is higher in AS-OPs compared to in HC-OPs. We also validated the increased BMPR2 expression in facet joint tissues with AS and its derived OPs in messenger RNA and protein levels. Additionally, primary AS-OPs showed much greater response to osteogenic differentiation induced by BMP2 and a higher capacity for smad1/5/8-induced RUNX2 expression compared to HCs. @*Conclusion@#The expression of BMPR2 was found to be significantly increased in facet joint tissues of patients with AS. These findings suggest that BMPR2 may play a role in the BMP2-mediated progression of AS.

Comparison of a Cryopneumatic Compression Device and Ice Packs for Cryotherapy Following Anterior Cruciate Ligament Reconstruction

Background@#The purpose of the current study was to evaluate and compare the effectiveness of a cryopneumatic compression device with that of standard ice packs following arthroscopic anterior cruciate ligament (ACL) reconstruction, with a primary focus on early postoperative pain. @*Methods@#Participants were divided into two groups: cryopneumatic compression device group (CC group) and standard ice pack group (IP group). Patients in the CC Group (28 patients) received a cryopneumatic compression device (CTC-7, Daesung Maref) treatment, while patients in the IP group (28 patients) received standard ice pack cryotherapy postoperatively. All cryotherapy was applied three times (every 8 hours) per day for 20 minutes until discharge (postoperative day 7). Pain scores were assessed preoperatively and at 4, 7, and 14 days after surgery, and the primary outcome for analysis was pain at postoperative day 4 assessed using a visual analog scale (VAS). Other variables were opioid and rescue medication use, knee and thigh circumferences, postoperative drainage, and joint effusion quantified by a three-dimensional magnetic resonance imaging (MRI) reconstruction model. @*Results@#The mean pain VAS score and difference in VAS relative to the preoperative measurements for postoperative day 4 were significantly lower in the CC group than in the IP group (p = 0.001 and p = 0.007, respectively). The sum of postoperative drainage and effusion quantified by MRI showed a significant reduction of postoperative effusion in the CC group compared to the IP group (p = 0.015). The average total rescue medication consumption was comparable between the two groups. Circumferential measurements at days 7 and 14 postoperatively relative to those at day 4 (index day) demonstrated no significant differences between the groups. @*Conclusions@#Compared to standard ice packs, application of cryopneumatic compression was associated with a significant reduction in VAS pain scores and joint effusion during the early postoperative period following ACL reconstruction.

The TNF-NF-κB-DKK1 Axis Promoted Bone Formation in the Enthesis of Ankylosing Spondylitis

Objective@#This study aimed to determine the serum Dickkopf 1 (DKK1) levels in ankylosing spondylitis (AS) patients and decipher the mechanism of tumor necrosis factor (TNF)-mediated DKK1 regulation in human AS enthesis cells. @*Methods@#The sera were obtained from 103 patients with AS and 30 healthy controls (HCs). The enthesis of facet joints were obtained from 4 AS patients and 5 controls. The serum levels of DKK1 were measured using ELISA and compared between AS and HCs. The impact of TNF on DKK1 expression in human primary spinal enthesis cells was evaluated using various molecular biology techniques and bone formation indicators. @*Results@#AS patients showed higher serum DKK1 levels than HCs after adjusting for age (917.4 [615.3∼1,310.0] pg/mL vs. 826.2 [670.3∼927.8] pg/mL, p=0.043). TNF treatment promoted bone formation and DKK1 expression in both control enthesis cells and those of AS. This enhanced bone formation by TNF was pronounced in AS-enthesis than those of controls. Mechanically, TNF induced NF-κB activation upregulates the DKK1 transcript level. While, NF-κB inhibitor led to downregulate DKK1 expression in the enthesis. Besides, DKK1 overexpression promoted bone formation in enthesis. @*Conclusion@#TNF induced DKK1 expression in the enthesis through NF-κB activation. TNF-induced DKK1 expression may play a bone formation in the radiologic progression of ankylosing spondylitis.

The TNF-NF-κB-DKK1 Axis Promoted Bone Formation in the Enthesis of Ankylosing Spondylitis

Objective@#This study aimed to determine the serum Dickkopf 1 (DKK1) levels in ankylosing spondylitis (AS) patients and decipher the mechanism of tumor necrosis factor (TNF)-mediated DKK1 regulation in human AS enthesis cells. @*Methods@#The sera were obtained from 103 patients with AS and 30 healthy controls (HCs). The enthesis of facet joints were obtained from 4 AS patients and 5 controls. The serum levels of DKK1 were measured using ELISA and compared between AS and HCs. The impact of TNF on DKK1 expression in human primary spinal enthesis cells was evaluated using various molecular biology techniques and bone formation indicators. @*Results@#AS patients showed higher serum DKK1 levels than HCs after adjusting for age (917.4 [615.3∼1,310.0] pg/mL vs. 826.2 [670.3∼927.8] pg/mL, p=0.043). TNF treatment promoted bone formation and DKK1 expression in both control enthesis cells and those of AS. This enhanced bone formation by TNF was pronounced in AS-enthesis than those of controls. Mechanically, TNF induced NF-κB activation upregulates the DKK1 transcript level. While, NF-κB inhibitor led to downregulate DKK1 expression in the enthesis. Besides, DKK1 overexpression promoted bone formation in enthesis. @*Conclusion@#TNF induced DKK1 expression in the enthesis through NF-κB activation. TNF-induced DKK1 expression may play a bone formation in the radiologic progression of ankylosing spondylitis.

Effect of biologics in the level of cytokines in the synovial fluid of patients with ankylosing spondylitis

Background/Aims@#Biologics are very effective drugs for patients with ankylosing spondylitis (AS). However, there are patients who are not responding to biologics. This study aimed to evaluate the level of tumor necrosis factor α (TNF-α), interleukin (IL)-23, and IL-17 from synovial fluid in patients with AS and rheumatoid arthritis (RA) and differences of the level of those cytokines according to drugs. @*Methods@#Synovial fluid was obtained from 34 patients (42 samples) with AS and 45 patients (47 samples) with RA with active arthritis of the knee, and the cytokine levels were measured. The differences in the levels between patients treated with and without biologics (biologics and non-biologics groups, respectively) were analyzed in AS and RA. The correlations between cytokines were examined in the non-biologics and biologics groups. @*Results@#The TNF-α level in AS was significantly lower than that in RA (p = 0.016). The IL-17 and IL-23 levels were not different between AS and RA (p = 0.409 and p = 0.562, respectively). In AS and RA, TNF-α, IL-17, and IL-23 showed good correlation among each other in the non-biologics group. However, there was no significant correlation in biologics group. In some patients in the AS group, the IL-17 or IL-23 level was markedly elevated in the biologics group. @*Conclusions@#Treatment with biologics affects the cytokine profile in inflammatory synovial fluid in patients with both AS and RA. Furthermore, IL-23 and IL-17 cytokine might be an important factor in some patients who are unresponsive to biologics in AS.

MicroRNA-10b Plays a Role in Bone Formation by Suppressing Interleukin-22 in Ankylosing Spondylitis

OBJECTIVE: The microRNA (miR)-10b is the T helper (Th) 17 cell specific in patients with ankylosing spondylitis (AS). The interleukin (IL)-22, which is closely related to Th17 cells, has been implicated in the regulation of new bone formation in experimental models. Therefore, the aim of this study was to evaluate whether miR-10b affects bone formation via the IL-22 pathway in AS.METHODS: Primary CD4+ T cells from AS were purified and transfected with miR-10b, anti-miR-10b, or scramble. Cell-surface markers and cytokine expression were analyzed by flow cytometry and enzyme-linked immunosorbent assay. Primary bone-derived cells (BdCs) from the facet joints of the spine were isolated, then osteogenic differentiation of primary BdCs was performed. We assessed alkaline phosphatase (ALP) activity and staining of BdCs at early time points. Alizarin red S staining of BdCs was performed at late time points.RESULTS: Overexpression of miR-10b reduced both IL-22 producing cell frequencies and cytokine production in T cells from the patients with AS. The IL-22 significantly increased ALP staining and bone mineralization. The ALP promotor activity of AS-BdCs was notably higher for the IL-22 concentration. The supernatants of the miR-10b overexpression group suppressed ALP activity on osteogenic progenitor cells from the facet joints of the spine in patients with AS.CONCLUSION: Our data suggest that miR-10b suppresses IL-22 production, which was involved in osteogenic proliferation in AS. Therefore, miR-10b might be a potential therapeutic candidate for regulation of new bone formation in patients with AS.

Downregulation of SIRT2 by Chronic Stress Reduces Expression of Synaptic Plasticity-related Genes through the Upregulation of Ehmt2

Silent information regulator 2 (Sirtuin2 / SIRT2) is a NAD⁺-dependent deacetylase that regulates the cellular oxidative stress response. It modulates transcriptional silencing and protein stability through deacetylation of target proteins including histones. Previous studies have shown that SIRT2 plays a role in mood disorders and hippocampus-dependent cognitive function, but the underlying neurobiological mechanism is poorly understood. Here, we report that chronic stress suppresses SIRT2 expression in the hippocampus. Molecular and biochemical analyses indicate that the stress-induced decrease in the SIRT2 expression downregulates synaptic plasticity-related genes in the hippocampus through the increase of euchromatic histone-lysine N-methyltransferase 2 (Ehmt2) (also known as G9a). shRNA-mediated knockdown of SIRT2 in the dentate gyrus alters the expression of synaptic plasticity-related genes in a way similar to those induced by chronic stress, and produces depression-like behaviors. Our results indicate that SIRT2 plays an important role in the response to stress, thereby modulating depression-like behaviors.

Capsaicin upregulates HDAC2 via TRPV1 and impairs neuronal maturation in mice

Transient receptor potential vanilloid 1 (TRPV1) affects mood and neuroplasticity in the brain, where its role is poorly understood. In the present study we investigated whether capsaicin (8-methyl-N-vanillyl-trans-6-nonenamide), an agonist of TRPV1, induced chromatin remodeling and thereby altered gene expression related to synaptic plasticity. We found that capsaicin treatment resulted in upregulation of histone deacetylase 2 (HDAC2) in the mouse hippocampus and HDAC2 was enriched at Psd95, synaptophysin, GLUR1, GLUR2 promoters. Viral-mediated hippocampal knockdown of HDAC2 induced expression of Synapsin I and prevented the detrimental effects of capsaicin on Synapsin I expression in mice, supporting the role of HDAC2 in regulation of capsaicin-induced Synapsin I expression. Taken together, our findings implicate HDAC2 in capsaicin-induced transcriptional regulation of synaptic molecules and support the view that HDAC2 is a molecular link between TRPV1 activity and synaptic plasticity.