Overexpressed RAD51 promoted osteogenic differentiation by activating IGF1R/PI3K/AKT pathway in osteoblasts.

BACKGROUND: Osteoporosis (OP) is a skeleton disease induced by imbalance between osteoblast and osteoclast. Osteogenic differentiation of osteoblasts is of great importance, and the regulatory mechanisms are urgent to be studied. METHODS: Differentially expressed genes were screened from microarray profile related to OP patients. The dexamethasone (Dex) was used to induce osteogenic differentiation of MC3T3-E1 cells. MC3T3-E1 cells were exposed to microgravity environment to mimic OP model cells. Alizarin Red staining and alkaline phosphatase (ALP) staining were used to evaluate the role of RAD51 in osteogenic differentiation of OP model cells. Furthermore, qRT-PCR and western blot were applied to determine expression levels of genes and proteins. RESULTS: RAD51 expression was suppressed in OP patients and model cells. Alizarin Red staining and ALP staining intensity, the expression of osteogenesis-related proteins including runt-related transcription factor 2 (Runx2), osteocalcin (OCN), and collagen type I alpha1 (COL1A1) were increased by over-expressed RAD51. Furthermore, RAD51 related genes were enriched in IGF1 pathway, and up-regulated RAD51 activated IGF1 pathway. The effects of oe-RAD51 on osteogenic differentiation and IGF1 pathway were attenuated by IGF1R inhibitor BMS754807. CONCLUSIONS: Overexpressed RAD51 promoted osteogenic differentiation by activating IGF1R/PI3K/AKT signaling pathway in OP. RAD51 could be a potential therapeutic marker for OP.

Etanercept/celecoxib on improving MRI inflammation of active ankylosing spondylitis: A multicenter, open-label, randomized clinical trial.

Objective: To investigate the efficacy and safety of clinical, magnetic resonance imaging (MRI) changes in active ankylosing spondylitis (AS) patients with etanercept and celecoxib alone/combined treatment. Methods: A randomized controlled trial was conducted in three medical centers in China. Adult AS patients with BASDAI ≥4 or ASDAS ≥2.1, CRP >6 mg/L, or ESR 28 mm/1st hour were randomly assigned (1:1:1 ratio) to celecoxib 200 mg bid or etanercept 50 mg qw or combined therapy for 52 weeks. The primary outcomes were SPARCC change of the sacroiliac joint (SIJ) and spine and the proportion of patients achieving ASAS20 response at 52 weeks. Results: Between September 2014 and January 2016, we randomly assigned 150 patients (mean age, 32.4 years; mean disease duration, 109 months), and 133 (88.6%) completed the study. SPARCC inflammation scores of the SIJ and spine decreased in the three groups, and significant differences were found between the combined group and the celecoxib group [between-group difference: -6.33, 95% CI (-10.56, -2.10) for SIJ; -9.53, 95% CI (-13.73, -5.33) for spine] and between the etanercept group and the celecoxib group [between-group difference: -5.02, 95% CI (-9.29, -0.76) for SIJ; -5.80, 95% CI (-10.04, -1.57) for spine]. The ASAS20 response rates were 44%, 58%, and 84% in the celecoxib, etanercept, and combined groups, respectively, and a significant difference was only found between the combined and the celecoxib groups. Conclusion: Etanercept with or without celecoxib decreases inflammation detected by MRI at 1 year compared to celecoxib alone in active AS patients. The combination of etanercept and celecoxib was superior to celecoxib alone for the primary clinical response. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT01934933.

Seronegative rheumatic arthritis has milder inflammation and bone erosion in an ultrasound study of disease-modifying anti-rheumatic drugs (DMARDs)-naïve Chinese cohort.

Background: Compared with the seropositive rheumatic arthritis (sp-RA), seronegative rheumatic arthritis (sn-RA) lacks ultrasound (US) research. It is unknown whether sn-RA patients had more severe synovitis than sp-RA ones at the same level of swollen joint counts (SJCs). We designed the US study to find out the answers. Methods: All cases satisfied the 2010 classification criteria, first diagnosed and disease-modifying anti-rheumatic drugs (DMARDs) naïve with the characteristics of abnormal swelling or pain in the wrist, proximal interphalangeal (PIPs), and metacarpophalangeal (MCPs) joints. Demographic data was collected. US examinations, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), visual analogue scale scores (VASs), patient global assessment (PGA), physician's global assessment (PhGA), disease activity score of 28 joints (DAS28), and van der Heijde-modified Sharp score (vdHSS) were used to evaluate the disease activity among these groups. Anticitrullinated peptide antibody (ACPA), rheumatoid factor (RF) and SJCs were used to divide the patients into 3 groups, which were defined as follows: Group A, sp-RA (positive RF and/or ACPA) with SJC >10; Group B, sp-RA with SJC ≤10; and Group C, sn-RA (all negative RF and ACPA with SJC >10 due to the criteria). Results: A total of 139 cases were recruited. Fifty-six were Group A, 54 were Group B, and 29 were Group C. All indexes above and the total US scores were significantly lower in Group C than Group A (both groups with SJC >10) (ESR, CRP, VASs, PGA, PhGA, DAS28, vdHSS, US total score respectively: 58.8 vs. 37.5, P=0.009; 37.5 vs. 17.8, P=0.008; 61.7 vs. 52.8, P=0.032; 62.2 vs. 53.9, P=0.031; 59.8 vs. 48.3, P=0.029; 6.92 vs. 5.56, P=0.000; 61.7 vs. 44.5, P=0.023; 31.4 vs. 20.9, P=0.000). The difference of the total US scores above was mostly contributed by the symptoms of synovitis. The total US scores were prominently lower in Group C with the duration over 2 years (2-5 years, >5 years, respectively compared to <2 years: 16.3 vs. 27.4, P=0.044; 16.5 vs. 27.4, P=0.048), and vdHSS were remarkably higher in almost all groups with a duration of over 5 years. For the patients with a duration over 2 years, bone erosions occurred earlier in sp-RA than in sn-RA patients. Conclusions: Sn-RA patients had milder synovitis than sp-RA ones at the same extent of disease activity. In addition, sn-RA had delayed progress of bone erosion than the sp-RA group.

Ataxia-televangelist mutated (ATM)/ ATR serine/threonine kinase (ATR)-mediated RAD51 recombinase (RAD51) promotes osteogenic differentiation and inhibits osteoclastogenesis in osteoporosis.

Osteoporosis is a metabolic bone disease that significantly affects the quality of life and can even lead to death. In this study, we aimed to investigate the role of RAD51 recombinase (RAD51) in osteoblast and osteoclast differentiation. We analyzed differentially expressed genes using microarray analysis. The osteogenic differentiation capability was analyzed by alkaline phosphatase (ALP) staining and alizarin red staining assays. Osteogenesis and osteoclast related genes expression was detected using quantitative real-time PCR (qPCR) and Western blotting. The phosphorylation of Ataxia-telangiectasia mutated (ATM) and ATR serine/threonine kinase (ATR) was tested using Western blotting. The effect of RAD51 on osteoporosis was also explored in vivo. The results showed that RAD51 was downregulated in osteoporosis, but upregulated in differentiated osteoblasts. Overexpression of RAD51 enhanced the differentiation of osteoblasts and suppressed the formation of osteoclasts. Furthermore, p-ATM and p-ATR levels were upregulated in osteoblasts and downregulated in osteoclasts. RAD51 expression was reduced by the ATM/ATR pathway inhibitor AZ20. AZ20 treatment inhibited osteoblastogenesis and promoted osteoclastogenesis, whereas RAD51 reversed the effects induced by AZ20. Moreover, RAD51 improved bone microarchitecture in vivo. Taken together, ATM/ATR signaling-mediated RAD51 promoted osteogenic differentiation and suppressed osteoclastogenesis. These findings reveal a critical role for RAD51 in osteoporosis.

TNF-α inhibitor therapy can improve the immune imbalance of CD4+ T cells and negative regulatory cells but not CD8+ T cells in ankylosing spondylitis.

BACKGROUND: Studies into ankylosing spondylitis (AS) and its relationship with immune imbalance are controversial, and the correlation between the efficacy of TNF-α inhibitor and changes in immune imbalance is unclear. METHODS: A total of 40 immune cells were tested with flow cytometry, and the results of 105 healthy control (HC) subjects, 177 active-stage AS patients, and 23 AS cases before and after 12 weeks of TNF-α inhibitor therapy (Anbainuo) were analyzed. RESULTS: Compared with the HC group, the proportion of immune cells, such as naïve and central memory CD4+T cells, in AS increased (P < 0.0001), but effector memory and terminally differentiated CD4+T cells were decreased (P < 0.01 and 0.0001, respectively). Naïve, central memory, and effector memory CD8+T cells were increased (P < 0.0001, 0.001, and 0.01, respectively), but terminally differentiated CD8+T cells were decreased (P < 0.0001). Th1 cells (helper T cells-1), Tfh1 cells (follicular helper T cells-1), Tc1 cells (cytotoxic T cells-1), and Tregs (regulatory T cells) were lower (P < 0.01, 0.05, 0.0001, and 0.001, respectively), but Th17 cells, Tfh17 cells, and Tc cells were higher (P < 0.001, 0.0001, and 0.001, respectively). The proportions of total B cells and class-switched B cells were increased (P < 0.05), but non-switched B cells, plasma cells, memory B cells, and immature Bregs (regulatory B cells) were lower (P < 0.01, 0.0001, 0.0001, and 0.0001, respectively). After Anbainuo therapy, the percentage of naïve CD4+ T cells had decreased (P < 0.05) but Tregs and B10 cells (IL-10-producing regulatory B cells) had increased (P < 0.01 and 0.05, respectively), and the increase in Tregs was positively correlated with the decrease in C-reactive protein (CRP) (r = 0.489, P = 0.018). CONCLUSIONS: We found that active-stage AS patients have an immunity imbalance of frequency involving multiple types of immune cells, including CD4+T cells, CD8+T cells, Th cells, Tfh cells, Tc cells, Tregs, Bregs, and B cells. TNF-α inhibitor Anbainuo can not only help to inhibit disease activity but can also improve the immune imbalance of CD4+ T cells and negative regulatory cells in frequency. But CD8+ T cells have not been rescued.

Circulating Retinol-Binding Protein 4 as a Possible Biomarker of Treatment Response for Ankylosing Spondylitis: An Array-Based Comparative Study.

OBJECTIVE: To explore proteins associated with ankylosing spondylitis (AS) and to investigate potential proteins that may predict treatment response of adalimumab (ADA) in AS patients. METHODS: In the discovery cohort, 39 AS patients and 20 healthy controls (HCs) were included, and 16 AS patients received ADA treatment for 24 weeks after included. In the validation cohort, 43 AS patients and 39 HCs were enrolled, and all 43 patients received ADA treatment after enrollment. Blood samples and clinical information were collected from two cohorts at baseline from all participants and week 24 from patients received ADA treatment. A human antibody array containing 1,000 proteins was used in the discovery phase, and Elisa kits were used for protein validation. RESULTS: Compared with HCs, we identified 53 differentially expressed proteins (DEPs) in AS patients. Bioinformatics analysis revealed they were mostly enriched in coagulation function-related pathways, acute response signaling, and LXR/RXR activation. Bone metabolism pathways were also associated. Comparison between samples of pre- and post-ADA treatment revealed 42 DEPs. They were mostly associated with bone metabolism and inflammation response pathways. Significant enrichment was also found in LXR/RXR activation but not the coagulation function-related pathways. Upstream regulator analysis suggested that most regulators also significantly functioned under usage of ADA. Precisely, seven proteins were abnormally expressed in AS and restored after ADA treatment. Retinol-binding protein 4 (RBP4), one of the seven proteins, was validated that its baseline levels were inversely correlated with improvements in Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP). Likewise, percentage changes in RBP4 levels were inversely correlated with changes in ASDAS-CRP score. CONCLUSION: A dysregulated serum protein profile existed in AS. ADA exerted a considerable but not entire alteration toward the dysregulation. RBP4 could be a biomarker for predicting and monitoring ADA treatment response.

Using Mobile Apps for Health Management: A New Health Care Mode in China.

BACKGROUND: China has a large population; however, medical resources are unevenly distributed and extremely limited, and more medical services are needed. With the development and ever-increasing popularity of mobile internet communication, China has created a mode of mobile health (mHealth) care to resolve this problem. OBJECTIVE: The aim of this study was (1) to describe the problems associated with China's medical care practice, (2) explore the need for and the feasibility of internet-based medical care in China, and (3) analyze the functionality of and services offered by internet-based health care platforms for the management of chronic diseases. METHODS: Data search was performed by searching national websites, the popular search engine Baidu, the App Store, and websites of internet medical care institutions, using search terms like "mobile health," "Internet health," "mobile medical," "Internet medical," "digital medical," "digital health," and "online doctor." A total of 6 mobile apps and websites with the biggest enrollment targeting doctors and end users with chronic diseases in China were selected. RESULTS: We recognized the limitations of medical and health care providers and unequal distribution of medical resources in China. An mHealth care platform is a novel and efficient way for doctors and patients to follow up and manage chronic diseases. Services offered by these platforms include reservation and payment, medical consultation, medical education assessment, pharmaceutical and medical instruments sales, electronic medical records, and chronic disease management. China's health policies are now strongly promoting the implementation of mHealth solutions, particularly in response to the increasing burden of chronic diseases and aging in the population. CONCLUSIONS: China's internet-based medical and health care mode can benefit the populace by providing people with high-quality medical resources. This can help other countries and regions with high population density and unevenly distributed medical resources manage their health care concerns.

Aberrant expression of microRNAs in peripheral blood mononuclear cells as candidate biomarkers in patients with axial spondyloarthritis.

OBJECTIVES: Axial spondyloarthritis (axSpA) is a chronic inflammatory arthritis involving the axial skeleton. Recent evidence suggests that microRNAs (miRNAs) play a critical role in ankylosing spondylitis (AS). In this study, we aimed to investigate whether miR-17-5p, miR-27a, miR-29a and miR-126-3p can be verified as potential biomarkers of axSpA. METHODS: Peripheral blood mononuclear cell (PBMC) miRNA expression was evaluated by quantitative real-time polymerase chain reaction among 43 patients with AS, 26 patients with non-radiographic axSpA (nr-axSpA) and 39 healthy controls. Detailed clinical histories were recorded and the correlation of miRNAs and clinical features were analyzed. RESULTS: When compared to controls, both patients with AS and nr-axSpA had significantly higher expression levels of miR-17-5p, miR-27a, miR-29a and miR-126-3p. MiR-27a was negatively correlated with Ankylosing Spondylitis Disease Activity Score as well as C-reactive protein in patients with nr-axSpA (r = -0.51, P < 0.01 and r = -0.42, P = 0.034 respectively). No other clinical features were found to correlate with the four miRNAs in patients with AS. Mir-29a showed highest area under the curve with 0.952 and these four miRNAs may be potential biomarkers in patients with axSpA. CONCLUSIONS: We reported elevated miR-17-5p, miR-27a, miR-29a and miR-126-3p expression in PBMCs of patients with axSpA, and the expression of these four miRNAs might be used as useful diagnostic markers in axSpA.

Possible predictors for relapse from etanercept discontinuation in ankylosing spondylitis patients in remission: a three years' following-up study.

The aim of this study is to assess the recurrence probability and the possible predictors in patients with ankylosing spondylitis from etanercept discontinuation in a 3-year observational cohort ( ClinicalTrials.gov : NCT02915354). A cohort of 35 patients who achieved an ASAS 20 response at the end of a randomized controlled trial underwent a 3-year follow-up evaluation. The primary end point was clinical relapse defined as the BASDAI score going back to 80% of its initial level at the beginning of the trial. Prognostic factors of relapse were analyzed using the Cox regression. Median duration of clinical remission was 15.0 months (interquartile range, 3.7-26.3 months). The cumulative probabilities of relapse at 1, 2, and 3 years were 45.7, 57.1, and 60.0%, respectively. The proportion of recurrence was not significantly different between placebo group and etanercept group by Kaplan-Meier analysis (placebo vs. etanercept: 61.11 vs. 58.82%, P = 0.890). Two independent factors associated with increasing risk of relapse were (1) age of patients (25 years or older with risk of 3.07, 95% confidence interval, 1.19-7.97, P = 0.021); (2) onset age (younger than 24 years with risk of 3.12, 95% confidence interval, 1.24-7.83, P = 0.016). No correlation was observed in the present study between the time of relapse and the duration of the treatment with etanercept in AS patients who achieved the ASAS 20 response after receiving the treatment. The older age and younger onset age of patients seems to be important factors associate with an increasing risk of relapse.

Effects and safety of 99Tc-MDP in patients with refractory ankylosing spondylitis: a 2-stage (30-week follow-up) clinical trial.

OBJECTIVES: To evaluate the clinical efficacy and safety in patients with refractory ankylosing spondylitis (AS) initiating 99Tc-MDP therapy and explore the mechanisms. METHODS: Refractory AS patients were enrolled in the clinical trial and received 99Tc-MDP treatments for 3 or 5 courses according to ASAS improvement. Efficacy and safety evaluations were conducted during the follow-up. 37 cytokines were quantified by Luminex at baseline and week 30. p-values<0.05 were considered statistically significant. RESULTS: 51 refractory AS patients were included, with 20 healthy people serving as the control group. The patients were in an active disease state (mean (SD) ASDAS 3.66 (0.83), BASDAI 4.53 (1.92)), 42(82.35%) patients had syndesmophytes. Their cytokines were significantly higher than that in the control group. After 3 courses of 99Tc-MDP treatment, 32 (62.75%) patients achieved ASAS20 improvement, 24 (47.06%) patients achieved a clinically significant improvement (ΔASDAS-CRP≥1.1). 27 patients entered the second stage to complete 5 courses of the treatment, all of whom achieved ASAS20 improvement, 18 (66.67%) patients achieved a clinically significant improvement. All clinical parameters including ASAS and ASDAS significantly improved as the treatment was continued. Cytokines also had significant down-regulation after the treatment, and the reductions had positive correlations with the improvements of disease activity. No serious adverse event was observed. CONCLUSIONS: This investigation confirmed the remarkable efficacy of 99Tc-MDP in a large number of refractory AS patients, and highlighted the mechanism by dramatic regulation on cytokines. 99Tc-MDP was safe in clinical application.

Backfill is a specific sign of axial spondyloarthritis seen on MRI.

OBJECTIVES: To summarize the characteristics of backfill in patients with axial spondyloarthritis (SpA) and patients with non-specific back pain (NSBP) and healthy controls, and to assess the value of backfill in diagnosing axial SpA. METHODS: Three readers blinded recorded backfill seen on T1SE MRI scans from 647 subjects: 297 patients with ankylosing spondylitis (AS), 126 patients with non-radiographic axial SpA (nr-axSpA), 147 patients with NSBP, and 77 healthy controls. The SPARCC SIJ Structural Score (SSS) method was used to assess backfill. The changes of backfill were evaluated by the follow-up MRI scans from 157 patients. We summarized the characteristics of backfill and calculated its sensitivity and specificity for diagnosing axial SpA. RESULTS: Backfill was recorded in 78.8% AS patients, 11.1% nr-axSpA patients, 1.8% patients with NSBP, and no healthy control. Backfill affected more frequently at ilium bone, lower half of sacroiliac joints in axial SpA (both P<0.05). The SSS score of backfill was much higher in axial SpA than in patients with NSBP (both P<0.01) and it did not correlate with demographics and BASDAI, BASFI, and CRP (all P>0.05). The score of backfill only positively correlated with symptom duration in AS (r=0.251, P<0.01) and in nr-axSpA (r=0.743, P<0.01) patients. Only 8.9% patients had the change of backfill in an average follow-up time of 1.09 years. Backfill had high specificity (0.98) and moderate sensitivity (0.59) for diagnosing axial SpA. CONCLUSIONS: We summarized the characteristics of backfill and found that backfill is a specific sign of axial SpA seen on T1SE MRI.