TDP-43 maintains chondrocyte homeostasis and alleviates cartilage degradation in osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is the most prevalent age-related disorder due to cartilage degradation. Previous studies have identified aberrant chondrocyte homeostasis under extracellular stress as a key pathological mechanism behind cartilage degradation in OA. TDP-43, a DNA/RNA-binding protein has been demonstrated to participate in processing many extracellular stress responses; however, understanding of the role of TDP-43 in OA is limited. This study aims to investigate the role of TDP-43 in chondrocyte homeostasis and cartilage degradation in OA.

METHODS

The role of TDP-43 during degradation of cartilage is examined by experimental posttraumatic OA animal models and human cartilage specimens. Cartilage degradation is assessed by histological analysis, qPCR, and Western blot. The molecular mechanisms are investigated in vitro using human primary chondrocytes.

RESULTS

TDP-43 decreases significantly in degenerated cartilage. TDP-43 concentration is positively correlated with IL-1β concentration in synovial fluid derived from OA patients (Pearson r = 0.95, CI (95%) [0.80, 0.99], P < 0.0001). Intra-articular injection of recombinant TDP-43 significantly alleviates cartilage degradation and subchondral bone remodeling in vivo. In vitro mechanistic analyses show that TDP-43 maintains chondrocyte homeostasis under oxidative stress through regulating stress granule dynamics via G3BP1.

CONCLUSION

The present study indicates that TDP-43 maintains chondrocyte homeostasis under oxidative stress and alleviates cartilage degeneration in osteoarthritis, identifying TDP-43 as a potential target for the diagnosis and treatment of knee OA.

POS0396 THE LEVEL OF PERIPHERAL REGULATORY T CELLS IS ASSOCIATED WITH THE CHANGES OF INTESTINAL MICROBIOTA IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a systemic autoimmunity inflammation disease characterized with chronic aggressive arthritis and the presence of abnormal antibodies. Several observations showed that the breakdown of immune tolerance caused by many complex interactions was involved in the development of RA[1]. However, the pathogenesis of RA remained unclear. It has been confirmed that the imbalance of Th17 and Treg cells play a crucial role in destroying immune tolerance [2]. Besides, researches showed that intestinal microbiota can influence host immunity by acting on the immune cells to play pro-inflammatory or anti-inflammatory effect, and in turn immune system can also regulate the microbiota[3, 4]. Thus, a frontier point of view in the field of rheumatism, immune microecology, was proposed, which is a novel concept for the breakdown of immune tolerance. Studies have confirmed that there was an imbalance of intestinal microbiota in patients with RA [4]. But the relationship between the CD4+T subsets cells and intestinal microbiota in RA is unknown.

Objectives:

We detected and compared the absolute number of CD4+T cells subsets in the peripheral blood and the proportion or abundance of intestinal microbiota in patients with RA and healthy adults, and then analyzed the relationship between them to explore the role of CD4+T cells subsets and intestinal microbiota in the pathogenesis of RA.

Methods:

We collected the sample of stool and blood from 15 patients with RA hospitalized at the Second Hospital of Shanxi Medical University and 8 age and gender-matched healthy controls(HC). The absolute number of CD4+T cells subsets including Th1, Th2, Th17 and Treg cells were detected by flow cytometry. The 16S rRNA in the stool specimens were sequenced by the Roche/45 high-throughput sequencing platform. We analyzed whether there was correlarion between CD4+T subsets cells and intestinal microbiota.

Results:

Patients with RA had a higher level of Christensenellaceae and a lower level of Pseudomonadaceae as compared with those of HCs at the family level (p<0.05). And at the genus level, the patients with RA had higher levels of Ruminococcus torques, Christensenellaceae R-7, Ruminiclostridium 9 and Ruminococcus 1 compared with those of HCs (p<0.05) (Figure 1).And the Ruminococcus torques at the genus level was negative correlated with the absolute number of Treg cells (p<0.001) (Figure 2).

Conclusion:

The results here suggested that there were different proportion or abundance of intestinal microbiota between the patients with RA andHCs. And the changes of intestinal microbiota such as Ruminococcus torques were associated with Treg cells, further indicating that the imbalance of intestinal microbiota in RA can destory the immune tolerance. The above results uncovered that the intestinal microbiota had immunomodulatory function, which may be the upstream mechanism participated in the pathogenesis of RA.

References:

[1]Weyand CM, Goronzy JJ. The immunology of rheumatoid arthritis. Nat Immunol 2021, 22(1): 10-18.

[2]Weyand CM, Goronzy JJ. Immunometabolism in the development of rheumatoid arthritis. Immunol Rev 2020, 294(1): 177-187.

[3]Brown EM, Kenny DJ, Xavier RJ. Gut Microbiota Regulation of T Cells During Inflammation and Autoimmunity. Annu Rev Immunol 2019, 37: 599-624.

[4]du Teil Espina M, Gabarrini G, Harmsen HJM, Westra J, van Winkelhoff AJ, van Dijl JM. Talk to your gut: the oral-gut microbiome axis and its immunomodulatory role in the etiology of rheumatoid arthritis. FEMS Microbiol Rev 2019, 43(1).

Figure 1.

At the family level (a-b) and the genus level(c-f), the relative abundance of intestinal microbiota in patients with RA and HCs were different. Data were expressed as median (Q1, Q3) and analyzed by Wilcoxon test. (*** P < 0.001, **P < 0.01 and *P < 0.05).

Figure 2.

A heatmap shows the correlation between the intestinal microbiota and CD4+T cells in patients with RA, and Ruminococcus torques at the genus level was negative related with Treg cells. (Colors indicate the Spearman rank correlation, *** P < 0.001).

Disclosure of Interests:

None declared

CGRP Regulates the Age-Related Switch Between Osteoblast and Adipocyte Differentiation

Osteoporosis is a chronic age-related disease. During aging, bone marrow-derived mesenchymal stem cells (BMSCs) display increased adipogenic, along with decreased osteogenic, differentiation capacity. The aim of the present study was to investigate the effect of calcitonin gene-related peptide (CGRP) on the osteogenic and adipogenic differentiation potential of BMSC-derived osteoblasts. Here, we found that the level of CGRP was markedly lower in bone marrow supernatant from aged mice compared with that in young mice. In vitro experiments indicated that CGRP promoted the osteogenic differentiation of BMSCs while inhibiting their adipogenic differentiation. Compared with vehicle-treated controls, aged mice treated with CGRP showed a substantial promotion of bone formation and a reduction in fat accumulation in the bone marrow. Similarly, we found that CGRP could significantly enhance bone formation in ovariectomized (OVX) mice in vivo. Together, our results suggested that CGRP may be a key regulator of the age-related switch between osteogenesis and adipogenesis in BMSCs and may represent a potential therapeutic strategy for the treatment of age-related bone loss.

CircABCB10 promotes the proliferation and migration of lung cancer cells through down-regulating microRNA-217 expression

OBJECTIVE

We aimed at studying the role and molecular mechanism of circular RNA circABCB10 in the progression of lung cancer (LCa).

PATIENTS AND METHODS

We collected LCa tissues using quantitative real-time polymerase chain reaction (qRT-PCR) technology to determine circABCB10 expression and performed survival analysis based on the clinical data of LCa patients. At the same time, the specific effects of circABCB10 on the biological function of LCa cell lines were determined by certain cell function experiments, including cell counting kit-8 (CCK-8) test, plate cloning experiment, transwell and cell wound healing assays. The downstream key gene microRNA-217 of circABCB10 was predicted through bioinformatics analysis and the potential regulation between them was confirmed by luciferase assay. microRNA-217 was knocked down in LCa cell lines to verify its important role in the progression of LCa.

RESULTS

CircABCB10 showed abnormally high expression in LCa tissues and cell lines and was related to the poor prognosis of patients. In vitro cell experiments demonstrated that knocking down circABCB10 remarkably suppressed the proliferation and migration ability of LCa cells. In addition, circABCB10 can specifically bind to microRNA-217 and negatively regulate its expression of microRNA-217 in LCa cells. Finally, cell functional experiments showed that microRNA-217 is a key downstream gene that mediates the regulation of circABCB10 on LCa cell function.

CONCLUSIONS

CircABCB10, abnormally highly expressed in LCa tissues, is able to induce the malignant progression of this cancer.

Circ_0134111 knockdown relieves IL-1β-induced apoptosis, inflammation and extracellular matrix degradation in human chondrocytes through the circ_0134111-miR-515-5p-SOCS1 network

BACKGROUND

Osteoarthritis (OA) is characterized by chondrocyte injury and dysfunction, such as excessive apoptosis, inflammatory response and extracellular matrix (ECM) degradation. Circular RNA (circRNA) deregulation is reported to be involved in OA. Our study aimed to explore the role of circ_0134111 in OA.

METHODS

Human chondrocytes were treated with interleukin-1β (IL-1β) to mimic OA cell model. The expression of circ_0134111, miR-515-5p and suppressor of cytokine signaling 1 (SOCS1) mRNA was measured by real-time quantitative polymerase chain reaction (RT-qPCR), and the protein levels of SOCS1 and apoptosis-/inflammation-/ECM-related markers were determined by western blot. Cell proliferation and cell apoptosis were assessed using cell counting kit-8 (CCK-8) and flow cytometry assay, respectively. For mechanism analysis, the predicted interaction between miR-515-5p and circ_0134111 or SOCS1 was verified by dual-luciferase reporter assay, pull-down assay and RNA immunoprecipitation (RIP) assay. Rescue experiments were performed to explore the interplay between miR-515-5p and circ_0134111 or SOCS1.

RESULTS

Circ_0134111 was overexpressed in OA cartilage tissues and IL-1β-induced chondrocytes. IL-1β-induced chondrocyte apoptosis, inflammatory responses and ECM degradation were alleviated by circ_0134111 knockdown or miR-515-5p restoration. Circ_0134111 acted as miR-515-5p sponge to regulate miR-515-5p expression, and miR-515-5p deficiency reversed the effects of circ_0134111 knockdown in IL-1β-induced chondrocytes. MiR-515-5p directly bound to SOCS1, and circ_0134111 decoyed miR-515-5p to increase SOCS1 level. MiR-515-5p restoration alleviated IL-1β-induced chondrocyte apoptosis, inflammatory responses and ECM degradation, While SOCS1 overexpression partly abolished these effects.

CONCLUSION

Circ_0134111 knockdown alleviated apoptosis, inflammatory responses and ECM degradation in OA cell model by mediating the miR-515-5p-SOCS1 network, hinting that circ_0134111 was involved in OA progression.

Texture analysis applied in T1 maps and extracellular volume obtained using cardiac MRI in the diagnosis of hypertrophic cardiomyopathy and hypertensive heart disease compared with normal controls

AIM

To assess the potential of texture analysis (TA) applied in T1 maps and extracellular volume (ECV) obtained using cardiac magnetic resonance (CMR) in the diagnosis of hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HHD) compared with normal controls (NC). Strain parameters were analysed to compare with final TA models.

MATERIALS AND METHODS

This retrospective study included 66 HCM patients, 39 HHD patients, and 41 NC. Step-wise dimension reduction and feature selection were performed by reproducibility, machine learning, collinearity, and multivariable regression analysis to select the texture features that enable diagnosis of and differentiation between HCM and HHD. Strain parameters were calculated by short-axis and three long-axis cine sequences.

RESULTS

Independent features in T1 maps and ECV analysis allowed for the differentiation between patients (HCM and HHD) and NC. Of the best-calculated model, the areas under the receiver operating curve (AUCs) were as follows: 0.969 for T1 map and 0.964 for ECV. To distinguish HCM from HHD, two independent features were screened out for both T1 and ECV maps. The AUCs were as follows: 0.793 for T1 map and 0.894 for ECV. Radial, circumferential, and longitudinal strain parameters could differentiate patients from NC, but only longitudinal strain parameters was significantly different between HCM and HHD.

CONCLUSIONS

Texture analysis of T1 maps and ECV shows high accuracy in differentiating hypertrophic myocardium from NC, and HCM from HHD. Strain parameters are able to demonstrate the difference between patients and NC, but were less impressive in differentiating HCM and HHD.

SAT0278 LOW-DOSE IL-2 RESTORES TREG-MEDIATED IMMUNE TOLERANCE IN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS

Background:

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune disease that can cause systemic organ damage, including granulomatosis with polyangiitis(GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis(EGPA)[1]. Several observations have showed that the breakdown of immune tolerance was involved in the pathogenesis of AAV [2], furthermore, a single, open and clinical trial demonstrates that IL-2 can be used to treat patients with GPA [3]. But there is still a lack of understanding of the relationship between Th17 / Treg and AAV and evidence for the therapeutic effect of IL-2 on AAV, which needs further exploration.

Objectives:

We first measured the absolute number of CD4+T subsets in peripheral blood of patients to explore the pathogenesis of AAV, and then investigated the effects of short-term and low-dose recombinant human IL-2 (rhIL-2) on CD4+T subsets of patients to analyze the regulatory effect of IL-2 on AAV.

Methods:

49 patients with AAV, hospitalized at the Second Hospital of Shanxi Medical University from the May 2016 to the November 2019 were enrolled, including 36 patients who were only received conventional glucocorticoids and DMARDs, and other 13 patients who were not only received these treatments but were also injected subcutaneously rhIL-2(50WIU/day for a 5-day course). 31 age and gender-matched healthy adults were selected as controls. The absolute number of Th17 and Treg cells in peripheral blood of health controls and the patients before and after treatment was detected by flow cytometry.

Results:

There was significant decreased level of Treg cells in the patients with AAV compared with healthy controls (P<0.001) leading to a higher Th17/Treg ratio in the patients with AAV, but there was no statistically significant in the absolute number of Th17 cells between the patients and healthy controls. After the treatment of short-term and low-dose IL-2, there was a significant increase in the absolute number of Treg cells (P<0.01) leading to a decrease in the ratio of Th17 and Treg (p<0.05).The absolute number of Th17 had a trend towards higher values but was not statistical significance.

Conclusion:

The difference of Treg cells between the patients and healthy controls suggested that the decreased number of Treg cells failed to control autoimmune inflammatory response contributing to the pathogenesis of AAV. After the treatment of short-term and low-dose rhIL-2, there was a more significant increase in the absolute number of Treg cells showing that IL-2 could selectively stimulate the growth of Treg cells and restore the Treg-mediated immune tolerance in patients with AAV to achieve disease remission.

References:

[1]Cosmi, L.,Th17 and Treg lymphocytes as cellular biomarkers of disease activity in Granulomatosis with Polyangiitis.Eur J Immunol, 2017.47(4): p. 633-636.

[2]Pagnoux, C.,Updates in ANCA-associated vasculitis.Eur J Rheumatol, 2016.3: p. 122-133.

[3]Rosenzwajg, M., et al.,Immunological and clinical effects of low-dose interleukin-2 across 11 autoimmune diseases in a single, open clinical trial.Annals of the Rheumatic Diseases, 2019.78(2): p. 209-217.

Disclosure of Interests:

None declared

THU0252 CORRELATION BETWEEN DISEASE ACTIVITY AND MENTAL HEALTH IN SLE PATIENTS: A CROSS-SECTION STUDY WITH SELF-ASSESSMENTS BASED ON SMART SYSTEM OF DISEASE MANAGEMENT (SSDM) MOBILE TOOLS

Background:

WHO survey showed that the prevalence of anxiety and depression in Chinese population and Chinese patients with chronic diseases were between 3.1% - 4.2% and 3.1% - 7.3%, respectively. SLEDAI-2K and Hospital Anxiety and Depression Scale (HADS) are commonly used to evaluate SLE patients’ disease activity and mental health. All the Assessments were mainly performed by health professionals (HCPs) with paper questionnaire previously. SSDM is a novel smart disease management tool that allows patients to do self-assessments on SLEDAI-2K and HADS by mobile App.

Objectives:

To investigate the prevalence of anxiety and depression in Chinese patients with SLE and to analyze the potential association between disease activity of SLE and mental health.

Methods:

Under the guidance and training by HCPs, SLE patients downloaded SSDM and performed self-assessments bundle of SLEDAI-2K and HADS with SSDM. SLEDAI-2K <=4, 5-9, 10-14 and >=15 are defined SLE inactive, low (LDA), moderate (MDA) and high (HDA) disease activity, respectively. SLEDAI-2K score <= 4 is set as the main criteria for Lupus Low Disease Activity State (LLDAS) and achievement of T2T. HADS score >=8 can be diagnosed with anxiety or depression.

Results:

From June 2016 to Jan 2020, 3,332 SLE patients (199 male, 3,133 female) with a mean age of 36.34 ± 12.80 (10-91) years and the median disease duration of 3.43 years from 216 hospitals performed bundle self-assessments for 4,967 times in total. According to the HADS and SLEDAI-2K Assessment results, the prevalence of anxiety and depression in all patients was 36.7% and 39.3% respectively, which was significantly higher than that in the WHO survey in Chinese population and chronic disease patients. The proportion of patients achieved and failed on LLDAS was 53% and 47%, respectively. The prevalence of anxiety (A) and depression (D) was 19% and 27% among LLDAS achievers; 41% and 47% among LLDAS failures, respectively (pA<0.01, pD<0.01).

According to SLEDAI-2K, in LLDAS, LDA, MDA and HDA subgroups, the prevalence of anxiety and depression was 19%, 30%, 37%, 54% and 27%, 36%, 44%, 61%, respectively. The correlation coefficients of anxiety (A) and depression (D) with SLEDAI-2K were rA=0.9957 and rD=0.9819. It suggested that with the increase of disease activity, the proportion of SLE patients with anxiety and depression increased significantly. (Figure 1)

Conclusion:

Conclusion: Higher prevalence of anxiety and depression were Associated with higher levels of disease activity in SLE patients. SSDM is an effective mobile interface to monitor and study entanglement of disease activity and mental health in SLE patients, which build a foundation for proactive interventions physically and mentally in future.

References:

Acknowledgments:

SSDM was developed by Shanghai Gothic Internet Technology Co., Ltd.

Disclosure of Interests:

None declared

AB1140 ABNORMAL RIGHT VENTRICLE RESERVE FOLLOWING EXERCISE IN PATIENTS WITH CONNECTIVE TISSUE DISEASES

Background:

Recent studies have indicated that cardiac autonomic dysfunction is an early sign of cardiovascular impairment in patients with connective tissue disease (CTD). Previous studies have mainly focused on autonomic regulation during rest in this population. The cardiac autonomic responses to an acute physiological stress might provide additional information on the autonomic dysfunction, serving as a powerful predictor of cardiovascular disease and mortality in patients with CTD.

Objectives:

We aimed to use exercise stress echocardiography to detect early right heart dysfunction in patients with CTD and healthy controls.

Methods:

Treadmill exercise stress echocardiography was performed in 19 CTD patients (8 systemic sclerosis, 6 mixed CTD and 5 SLE) and 20 healthy volunteers. Parameters of right ventricular (RV) systolic function (RV fractional area change, Doppler tissue s’ velocity, and systolic strain and strain rate) and diastolic function (peak E and A velocity, Doppler tissue e’, a’ and early and late diastolic strain rate) were evaluated at baseline and after exercise, with the difference (Δ) being systolic and diastolic reserve. The immunoblotting assay was performed to detect the levels of rheumatoid factor (RF) and C-reactive protein (CRP) as well as autoantibodies such as, antinuclear antibody (ANA), anti-U1 ribonucleoproteins (U1RNP), anti-dsDNA, anti-Sm, anti-SSA, anti-SSB, anti-SCL-70 and RO-52. The correlation between these proteins and RV function was analyzed.

Results:

Both the patients with CTD and healthy controls had a normal range of BMI, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG). The average age of patients with CTD was 46.0 ± 10.4 years. At baseline, these patients presented no cardiovascular disease or pulmonary hypertension. No significant difference in the body weight, height, age, sex, blood pressure, RV and left ventricular (LV) function at rest between the two groups (allP>0.05). The parameters of RV systolic reserve decreased significantly in CTD group compared to those of the healthy controls (Δs’: 5.8±2.1 vs 8.3±2.5cm-1,P<0.01; ΔSr: 2.5±0.8 vs 2.8±0.7s-1,P<0.01). Consistently, RV diastolic reserve was significantly decreased in CTD patients compared to controls (Δe’: 2.8±1.5 vs 3.9±2.3cm-1,P<0.05; Δa’: 5.8±2.5 vs 10.9±6.3cm-1,P<0.05; ΔE-Sr: 0.8±0.2 vs 1.2±0.5s-1,P<0.05; ΔA-Sr: 0.9±0.3 vs 1.3±0.6s-1,P<0.05). To identify independent predictors of RV function in CTD patients, linear regression was conducted. This suggested that ANA, anti-U1RNP, anti-dsDNA, anti-Sm, anti-SSA, anti-SSB, anti-SCL-70 and RO-52 were not correlated with RV reserve (allP>0.05). A logistic regression analysis revealed that RF (P<0.05) and CRP (P<0.01) were independently associated with RV reserve in CTD patients in response to an acute physiological stress.

Conclusion:

Treadmill exercise echocardiography could detect right heart dysfunction early before diagnosed as cardiovascular diseases in patients with CTD. RV reserve after exercise might be a promising parameter to detect cardiovascular disease early in CTD patients.

References:

[1]Lazzerini PE, Capecchi PL, Laghi-Pasini F. Systemic inflammation and arrhythmic risk: lessons from rheumatoid arthritis.Eur Heart J. 2017;38(22):1717–1727.

[2]Peçanha T, Rodrigues R, Pinto AJ, et al. Chronotropic Incompetence and Reduced Heart Rate Recovery in Rheumatoid Arthritis.J Clin Rheumatol. 2018;24(7):375–380.

Disclosure of Interests:

None declared

AB0028 IMBALANCES OF TH17/TREG IN CARDIOVASCULAR EVENTS OF PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Ankylosing spondylitis (AS) is a common inflammatory joint disease affecting articulations of axial skeleton and asymmetrical peripheral arthrosis. It has been highlighted that patients with AS exhibit an increased risk of cardiovascular diseases (CVD) compared to the general population [1]. However, little is known about the relationship between cardiovascular burden in AS patients and Th17/Treg imbalance.

Objectives:

We aimed to investigated the relationship between cardiovascular events in AS patients and the status of T cell subsets. Furthermore, we want to identify other clinical and/or laboratory features which are associated with the cardiovascular risk in AS patients.

Methods:

The study included 32 AS patients with cardiovascular diseases and 32 age-matched AS patients as controls. All the AS patients were hospitalised at the Second Hospital of Shanxi Medical University and met the diagnostic criteria for AS revised in New York in 1984. We collected demographics, laboratory features [erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), DD (D-dimer), PLT (platelet count)], and absolute counts of lymphocyte and CD4+ T cell subset. The absolute numbers of lymphocytes and CD4+ T cells in peripheral blood were measured by Flow Cytometer.

Results:

1. There was statistically significant decrease in Th17 levels (P=0.012) in the AS with CVD group compared to the AS group, while the Treg cells number (P=0.426) and the ratio of Th17/Treg (P=0.202) have no statistically significant differences; 2. DD was significantly increased in AS patients with CVD; 3. The use of NSAIDs between the two groups is significantly different(P=0.013). 86.7% of the AS group have received NSAIDs, while only 58.1% of the AS patients with CVD have received the NSAIDs.

Conclusion:

The findings suggested that the cardiovascular events of AS patients correlated with imbalanced T cell subsets and the decreased Th17 cells may be a laboratory feature of AS patients with CVD. Patients with high DD level might have a higher risk of CVD. Monitoring of Th17 cells and DD could be beneficial in cardiovascular burden of patients with AS. However, current studies indicate that Th17 cells mediate the inflammatory response and play a crucial role in the development of CVD [2]. One explanation is that the AS patients with CVD in our study had a long disease duration and immunomodulatory therapy might have an impact on the status of T cell subsets. Meanwhile, the different disease activities of AS patients can be additional factors.

References:

[1]Haroon N, Paterson J M, Li P, et al. Patients with Ankylosing Spondylitis Have Increased Cardiovascular and Cerebrovascular Mortality[J]. Annals of Internal Medicine, 2015, 163(6):409. doi:10.7326/M14-2470

[2]van Bruggen, N. and W. Ouyang, Th17 Cells at the Crossroads of Autoimmunity, Inflammation, and Atherosclerosis. Immunity, 2014. 40(1): p. 10-12. doi:https://doi.org/10.1016/j.immuni.2013.12.00

Table 1.

Absolute lymphocyte and CD4+ T cell subset counts (cells/μL) in the AS with CVD group and AS group

Cell count (cells/μL)AS with CVDASP-valueTotal T1447.97±11.491442.49±11.490.970Total B217.06(144.55- 324.97)291.27(171.13-321.16)0.262NK268.09(171.51-396.99)277.71(167.08- 462.45)0.858Th1137.23(69.8-185.45)127.04(76.9-197.26)0.693Th28.42(5.56-10.47)8.03(5.50-9.95)0.848Th175.77(4.00-8.61)8.89(5.91-13.88)0.012*Treg29.64(17.07-47.19)34.51(23.26-47.19)0.426Th1/Th214.99(10.50-24.21)17.36(12.71-25.98)0.430Th17/Treg0.23(0.12-0.39)0.31(0.18-0.52)0.202

*P<0.05 **p <0.01. Data with a normal distribution and homogeneity of variance are presented as mean±standard deviation. Data without a normal distribution are presented as the median (interquartile range)

Figure 1.

Differences in Treg, Th17 cell counts and Th17/Treg between AS with CVD group and AS group. There was statistically significant decrease in Th17 levels(P=0.012) in the AS with CVD group. * P < 0.05 **P < 0.01. Data were compared using the Wilcoxon’s rank sum test.

Disclosure of Interests:

None declared

THU0242 REGULATORY ROLE OF TRANSCRIPTION FACTOR BLIMP-1 IN SJÖGREN’S SYNDROME

Background:

The pathogenesis of primary sjögren’s syndrome (pSS) is multifactorial. Self-antigen-driven responses perform a vital function in the development of autoimmune diseases [1]. B cells, only 20-25% of total infiltrating cells in labial glands, are the cellular basis for spontaneous antibody production [2].Genome-wide association studies (GWAS) have identified Blimp-1 as a susceptibility gene for autoimmune diseases and played an important role in the pathogenesis of autoimmune diseases [3].

Objectives:

To investigate the expression and effect of B lymphocyte induced maturation protein 1 (Blimp-1) in pSS and the correlation of Blimp-1 with B cell subsets and clinical features.

Methods:

The PRDM1 mRNA expression in B lymphocyte and labial gland were examined by RT-PCR. The levels of B cell subsets were examined by flow cytometry. Hematoxylin-eosin (HE) staining and immunohistochemistry (IHC) were used to examine the invasion degree of lymph cell and Blimp-1 distribution, respectively. The correlation of PRDM1 mRNA with B cell subsets and clinical indicators were also analyzed.

Results:

The levels of PRDM1 mRNA expression of B cells were significantly higher in SS than in healthy controls (HC) and which were also significantly higher in the high immunoglobulin (Ig) group than that in normal Ig group (P<0.02, Fig. 1a-b). The number of CD19+B cells and CD138+ plasma cells(PC) have increased while the CD27+ cells decreased in SS(P<0.05). The percentage of PC and PC/B is positively correlated with PRDM1 mRNA(r=0.380,P=0.002;r=0.317,P=0.009, Fig. 1c-d). Blimp-1 expression level showed a positive correlation with invasion degree of lymph cell in histology (Fig. 2a-c), Ig levels and ESSDAI score and an inverse correlation with the glucocorticoids usage (Fig. 3c).

Fig. 1

(a-b) RT-PCR showed that PRDM1 mRNA expression in SS patients and HC. (c-d) Correlation between PRDM1 mRNA expression and PC and PC/B.

Fig. 2

(a) Expression of Blimp-1 in labial glands of sjögren’s syndrome. (b) PRDM1 mRNA levels in different invasion degree of lymph cell group. (c) Correlation between PRDM1 mRNA expression and invasion degree of lymph cell. *p<0.05, ***p<0.001.

Fig. 3

(a-b) RT-PCR showed that PRDM1 mRNA expression in different usage of glucocorticoids. (c) Correlation between PRDM1 mRNA expression and different glucocorticoid usage. **p<0.01, ***p<0.001.

Conclusion:

Blimp-1 displayed high expression in SS, which could affect pSS disease activity. SS activity is suppressed by glucocorticoid which might be through inhibition of Blimp-1.

References:

[1]Kapsogeorgou EK, Abu-Helu RF, Moutsopoulos HM, Manoussakis MN (2005) Salivary gland epithelial cell exosomes: A source of autoantigenic ribonucleoproteins. Arthritis Rheum 52(5):1517-21.https://doi.org/10.1002/art.21005

[2]Arneth BM (2019) Impact of B cells to the pathophysiology of multiple sclerosis. J Neuroinflammation 16(1):128.https://doi.org/10.1186/s12974-019-1517-1

[3]Bönelt P, Wöhner M, Minnich M et al (2019) Precocious expression of Blimp-1 in B cells causes autoimmune disease with increased self-reactive plasma cells. EMBO J 38(2). pii:e100010.https://doi.org/10.15252/embj.2018100010

Table 1.

Clinical characteristics of pSS and HC.

HC(n=17)pSS(n=50)Sex (Male/Female)0/170/50Age(x±s)45.24±18.5546.8±11.05Xerostomia(positive/negative)0/1743/7Keratoconjunctivitis sicca0/1735/15Arthralgia0/1732/18Fatigue0/1718/32ESSDAI(x±s)-2.78±1.61 (0~7)ESSPRI(x±s)-3.3±1.39 (1~6)ANA(positive/negative)-49/1SSA-49/1SSB-18/32

pSS: primary sjögren ‘s syndrome; HC: Healthy controls; ESSDAI: The European League Against Rheumatism Sjögren’s Syndrome Disease Activity Index; ESSPRI: EULAR Sjögren’s Syndrome Patient Reported Index.** P<0.01,*** P<0.001.

Acknowledgments :

This study was supported by the grants from the National Natural Science Foundation of China (81871271).

Disclosure of Interests: :

None declared