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.

A clinical practice guideline for the screening and assessment of enthesitis in patients with spondyloarthritis.

Objective: The aim of this review is to provide guidance on the selection of approaches to the screening and assessment of enthesitis in patients with spondyloarthritis (SpA). Methods: Twenty-four questions regarding the approaches to the screening and assessment of enthesitis and the implementation details were devised, followed by a systemic literature review. The Grading of Recommendations Assessment, Development, and Evaluation methodology was employed in the development of this guideline, with modifications to evaluate non-interventional approaches under comprehensive consideration of costs, accessibility, and evidence strength. A consensus from the voting panel was required for the inclusion of the final recommendations and the strength of each recommendation. Results: Seventeen recommendations (including five strong recommendations) were included in this guideline. The voting panel expressed unequivocal support for the necessity of screening and assessment of enthesitis in patients with SpA. It was agreed unanimously that symptom evaluation and physical examination should serve as the initial steps to the recognition of enthesitis, whereas Maastricht Ankylosing Spondylitis Enthesitis Score is a reliable tool in both clinical trials and daily medical practice. Ultrasound examination is another reliable tool, with power Doppler ultrasound as an informative addition. Notwithstanding its high resolution, MRI is limited by the costs and relatively low accessibility, whereas radiographs had low sensitivity and therefore should be rendered obsolete in the assessment of enthesitis. PET/CT was strongly opposed in the detection of enthesitis. Conclusion: This guideline provides clinicians with information regarding the screening and assessment of enthesitis in patients with SpA. However, this guideline does not intend on dictating choices, and the ultimate decisions should be made in light of the actual circumstances of the facilities.

The pattern and trends of disease burden due to low bone mineral density from 1990 to 2019 in China: findings from the Global Burden of Disease Study 2019.

Osteoporosis is becoming increasing important health problem in China. This study shows that the disease burden of low bone mineral density (BMD) in China is large and will remain increasing with the growth of aging population. In addition, male low BMD should not be ignored. Although burden of low BMD is partially representative of the real burden of osteoporosis, the information provided in our study could be used to better inform targeted public health prevention and management programs for osteopososis. PURPOSE: We aim to investigate the pattern and trends of disease burden due to low BMD by gender, year, and age in China from 1990 to 2019. METHODS: Data on summary exposure value (SEV) and disability-adjusted life years (DALYs) due to low BMD was obtained from the Global Burden of Disease Study 2019, and analyzed by gender, age, and years. Average annual percent change (AAPC) and annual percent change (APC) were calculated to qualify the trends of burden due to low BMD. RESULT: In 2019, the age-standardized SEV was higher in females than that in males (23.04, 95% UI = [17.25-29.83] and 12.50, 95% UI = [7.71-19.25], respectively), while the total number of DALYs was higher in males than females with 1,698,705.92 (95% UI = 1,281,580.79 to 2,076,364.25) and 1,621,569 (95% UI = 1,266,284.89 to 2,016,399.16), respectively. Though SEV exhibited decreasing trends during 1990 to 2019 in both sexes, the absolute number of DALYs due to low BMD increased steadily and almost doubled in 2019 compared to that in 1990. CONCLUSION: The burden of low BMD remains large and continues to increase. Although females are prone to low BMD, the disease burden for males should not be ignored.

Adalimumab Therapy Restores the Gut Microbiota in Patients With Ankylosing Spondylitis.

Growing evidence suggests that the gut microbiota is involved in the initiation and progression of ankylosing spondylitis (AS). In this study, we aimed to explore the gut microbiome alterations during adalimumab therapy and verify microbiome biomarkers predicting treatment response. By evaluating the gut microbial features of 30 AS patients before and after adalimumab therapy for 6 months and 24 healthy controls, we confirmed that the microbiome was restored remarkably after 6 months of adalimumab therapy in AS patients. We then compared the baseline gut microbiome of 22 adalimumab responders with 8 non-responders, a higher abundance of Comamonas was revealed in the latter, although no statistical difference was found after adjusting for the false discovery rate. These results suggested that adalimumab therapy restored the gut microbiome in AS patients and indicated the utility of gut microbiome to be potential biomarkers for therapeutic evaluation. These findings provided an insight into the development of predictive tools and the establishment of precise medical interventions for clinical practice.

Pain- and Fatigue-Related Functional and Structural Changes in Ankylosing Spondylitis: An fRMI Study.

Background: Chronic pain and fatigue are two cardinal features of ankylosing spondylitis (AS) and how to effectively treat these conditions continues to be a challenge. The underlying mechanisms and the relationship between AS-related pain and fatigue remain poorly understood. The present study was conducted, therefore, to explore the brain functional and structural changes associated with pain and fatigue in AS. Methods: A total of 65 AS patients (48 men and 17 women; 32.33 ± 8.6 years) and 53 age- and sex-matched controls were enrolled in the study. The patients underwent clinical assessment based on Total Back Pain scores, Fatigue Severity Scale, Bath Ankylosing Spondylitis Disease Activity Index, (BASDAI), high-sensitivity C-reactive Protein (hsCRP), erythrocyte sedimentation rate (ESR), and Beck Depression Inventory (BDI). Using 3T magnetic resonance imaging (3T-MRI), we analyzed the brain functional (connectivity and nodal properties) and structural (covariance and gray matter volumes) differences between AS patients and controls. Furthermore, we extracted the values of the significantly changed regions in the AS cohort and explored their association with pain and fatigue. Results: In AS patients, there were functional and structural abnormalities distributed in the default mode network (DMN), salience network (SN), sensory/somatomotor network (SMN), dorsal attention network (DAN), task control network (TCN), and visual network, and some regions showed both types of changes. Among these, the functional connectivity (FC) between the left insula and medial prefrontal cortex, the betweenness centrality of the left medial prefrontal cortex and the gray matter volume of the right putamen tracked both pain and fatigue. In addition, pain was related to within-DMN FC disruption and nodal function / gray matter volumes changes in DMN, SN, and the visual network, while fatigue mainly involved the SMN, DAN, and TCN. Moreover, certain changes were also related to BASDAI and inflammation level. Conclusion: This study offers new insights into understanding the neural mechanism of AS-related pain and fatigue, and could help to stratify patients based on the correlation features and ultimately move towards a personalized therapy.

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.

Genetic basis of relapsing polychondritis revealed by family-based whole-exome sequencing.

AIM: Genetic factors are believed to be implicated in the pathogenesis of relapsing polychondritis (RP). However, the molecular genetic determinants remain to be elucidated. This study aimed to detect the susceptibility genes of RP with whole-exome sequencing (WES) in a Chinese family and deepen our understanding of the pathogenesis of RP thereafter. METHOD: A 32-year-old Chinese female proband with RP and her family including her mother with RP were enrolled in the study. The genomic DNA of 6 human subjects was extracted from peripheral blood and then gene allele mutations were identified using WES. Candidate variants with low frequency (<0.1%) in the general population and predicted deleterious effects on gene function were identified. Sanger sequencing was applied subsequently to confirm the analyzed gene variants in 12 human blood samples. RESULTS: Nine single nucleotide polymorphism variants from different genes were identified to associate with RP by WES and further confirmed by Sanger sequencing, including Ring finger protein 207 (RNF207), collagen type XXII alpha 1 chain (COL22A1) rs200464636, glycosylphosphatidylinositol anchor attachment 1 (GPAA1) rs201424010, recQ like helicase 4 (RECQL4) rs757703895, folliculin (FLCN) NM_144606: c.G838A: p.E280K, DNA ligase 3 (LIG3) rs761808558, NM_207396: c.T425C:p.I142T, myosin heavy chain 15 (MYH15) NM_014981: c.G4462A: p.A1488T, purkinje cell protein 2 (PCP2) rs144974437 and coiled-coil domain containing 61 (CCDC61) rs777816675. CONCLUSIONS: This study suggests that coinheritance of multigene mutation may contribute to RP predisposition. The candidate genes mutated which we discovered are potential targets for in-depth functional studies.

Age-Specific Imbalance of Circulating Tfh Cell Subsets and Its Association With Gout-Targeted Kidney Impairment.

Objective: Gout is a chronic disease characterized by the deposition of monosodium urate (MSU) crystals in tissue. Study with a focus on adaptive immune response remains to be understood although innate immune response has been reported extensively in gout etiology. Our study attempted to investigate the association of gout-related immune cell imbalance with clinical features and comorbidity with renal impairment and the implicated pathogenesis via the assessment of T and B cell subsets in different activity phases or with immune effects combined with the analyses of clinical parameters. Methods: Fifty-eight gout patients and 56 age- and sex-matched healthy individuals were enrolled. To learn the roles of circulating T cells, a lymphocyte profile incorporating 32 T cell subsets was tested from isolated freshly peripheral blood monocyte cells (PBMCs) with multiple-color flow cytometry. Furthermore, the collected clinical features of participants were used to analyze the characteristics of these differential cell subsets. Stratified on the basis of the level of creatinine (Cr, enzymatic method), all patients were categorized into Crlow (Cr ≤ 116 µmol/L) and Crhi (Cr > 116 µmol/L) groups to exploit whether these gout-associated T cell subsets were functional in gout-targeted kidney dysfunction. The differentiation of B cells was investigated in gout patients. Results: Our results show that CD 4+ T cells, Th2 cells, and Tc2 cells were upregulated, whereas Tc17 cells were downregulated. Tfh cells skewed toward the polarization of Tfh2 cells. Specifically, Tfh2 cells increased, but Tfh1 cells decreased, accompanied with aging for gout patients, suggesting that age might trigger the skewing of Tfh1/Tfh2 cell subsets to influence gout development. Moreover, Tfh2 cells were connected to renal dysfunction as well. No alterations of B cell subsets were observed in patients when compared to controls. Conclusions: Our data demonstrate age-specific dysfunctions of Tfh1/2 cells in gout occurrence, and Tfh2 cell upregulation is associated with gout-targeted renal dysfunction. However, Tfh2 cells may function in auto-inflammatory gout independent of helping B differentiation, and an in-depth study remains to be conducted.

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.

An epidemiological study of the prevalence rate of inflammatory back pain and axial spondyloarthritis in a university in the south of China.

Inflammatory back pain (IBP) is an important clinical feature for axial spondyloarthritis (SpA). Yet, little is known about their prevalences in China. We conducted an epidemiological study in a university to detect the prevalences of IBP and axial SpA according to the Assessment of SpondyloArthritis International Society (ASAS) criteria. We investigated 3770 participants from South China Agricultural University by face-to-face questionnaires and evaluated the prevalences of chronic low back pain (CLBP) and IBP. In addition, 333 students including all IBP patients volunteered to do HLA-B27 test, and we performed X-ray examination on students with suspect axial SpA. Axial SpA was confirmed by rheumatologists according to ASAS criteria. The mean (± SD) age of screened population was 19.48 (± 2.80) years, while female to male ratio was 1.45:1 (2229/1541). Seven hundred thirty-one (19.39%) of all participants had CLBP and 111 (2.94%) had IBP. Among the 333 students receiving HLA-B27 test, 13 (0.34%, 13/3770) fulfilled ASAS criteria for axial SpA. Nine students had sacroiliitis on imaging plus at least one SpA feature (IBP and positive HLA-B27 results). Four students had positive HLA-B27 plus at least two other SpA features (arthritis/enthesitis and good response to NSAIDs). For CLBP, female/male was 485/246. For axial SpA, female/male was 4/9(P = 0.014). In southern China, the prevalences of CLBP and IBP were respectively 19.39 and 2.94% in university, and the prevalence of axial SpA was 0.34%. Although more female students had CLBP, males were more likely to suffer from axial SpA.

uPAR promotes tumor-like biologic behaviors of fibroblast-like synoviocytes through PI3K/Akt signaling pathway in patients with rheumatoid arthritis.

Urokinase-type plasminogen activator receptor (uPAR), is a multifunctional receptor on cell surface, widely present in endothelial cells, fibroblasts, and a variety of malignant cells. Current studies have suggested that uPAR overexpressed on synovial tissues or in synovial fluid or plasma in patients with rheumatoid arthritis (RA). However, there are limited researches regarding the role of uPAR on fibroblast-like synoviocytes of rheumatoid arthritis (RA-FLSs) and its underlying mechanisms. Here, our studies show that the expression of uPAR protein was significantly higher in fibroblast-like synoviocytes (FLSs) from RA than those from osteoarthritis or traumatic injury patients. uPAR gene silencing significantly inhibited RA-FLSs cell proliferation, restrained cell transformation from the G0/G1 phase to S phase, aggravated cell apoptosis, interfered with RA-FLSs cell migration and invasion, and reduced activation of the PI3K/Akt signaling pathway, which may be associated with ß1-integrin. Cell supernatants from uPAR gene-silenced RA-FLSs markedly inhibited the migration and tubule formation ability of the HUVECs (a human endothelial cell line). Therefore, we demonstrate that uPAR changes the biological characteristics of RA-FLSs, and affects neoangiogenesis of synovial tissues in patients with RA. All of these may be associated with the ß1-integrin/PI3K/Akt signaling pathway. These results imply that targeting uPAR and its downstream signal pathway may provide therapeutic effects in RA.

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.

Serum Vitamin D and Pyridinoline Cross-Linked Carboxyterminal Telopeptide of Type I Collagen in Patients with Ankylosing Spondylitis.

OBJECTIVE: To assess the serum vitamin D and ICTP levels in patients with ankylosing spondylitis (AS) and investigate their relationship with disease activity and bone mineral density (BMD). METHOD: 150 patients and 168 controls were included. Serum 25(OH)D, ICTP, C-reaction protein (CRP), Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), and Hip BMD were assessed in patients. 25(OH)D and ICTP were detected in controls. RESULTS: The serum 25(OH)D in AS was 57.92 ± 24.42 nmol/L, significantly lower than controls (91.24 ± 42.02 nmol/L). Serum ICTP in AS was 5.72 ± 3.88 ug/L, significantly higher than controls (3.69 ± 1.26 ug/L). ICTP level was higher in men than in women patients (6.07 ± 4.05 versus 3.84 ± 1.96 ug/L, P ≤ 0.01); it was also higher in JAS than in AAS (9.52 ± 3.79 versus 5.27 ± 3.65 ug/L, P ≤ 0.01). Furthermore, 25(OH)D was negatively correlated with ICTP. Low 25(OH)D and high ICTP were one of the reasons of AS patients' low hip BMD. Besides, a significant relationship was found between serum ICTP and CRP. CONCLUSION: There was a high incidence of vitamin D inadequacy in AS. Serum ICTP level was elevated in AS, especially in JAS and male patients. 25(OH)D and ICTP seem to be valuable markers to detect bone loss in AS.

Anti-TNF therapy in patients with HBV infection--analysis of 87 patients with inflammatory arthritis.

This study aims to investigate the incidence of hepatitis B virus (HBV) reactivation in inflammatory arthritis (IA) patients with HBV infection using anti-tumor necrosis factor (TNF) agents and evaluate the efficacy of antiviral therapy in reducing the risk of viral reactivation in chronic HBV infection. IA patients using anti-TNF agents from six centers were enrolled. Their HBV infection conditions and ALT and HBV-DNA levels were monitored periodically. Among the six chronic hepatitis B patients, HBV reactivation was found in two patients without antivirus prophylaxis and no viral replication was detected in the other four patients with antivirus prophylaxis. In the 31 inactive carriers, the increase of viral load was detected in 6 of 22 (27.3 %) patients without antiviral prophylaxis, and there was no viral reactivation in the other 9 patients with antiviral prophylaxis. HBV reactivation was not found in the 50 patients with resolved HBV infection. It is suggested that anti-TNF therapy might increase the risk of HBV reactivation in patients with chronic HBV infection, and antiviral prophylaxis could effectively decrease the risk. Anti-TNF agents seem to be safe in patients with resolved HBV infection.