Prediction of Self-Perception of Patient in Rheumatoid Arthritis With the Key RNAs Expression Profiles

[Expression of miR-342-3p in rheumatoid arthritis patients and its effect on synovial fibroblast inflammation and migration]

OBJECTIVE

To investigate the expression level of miR-342-3p in peripheral blood mononuclear cells (PBMCs) of patients with rheumatoid arthritis (RA) and its effect on inflammatory response and migration of synovial fibroblasts in RA (RA-FLS).

METHODS

PBMCs were collected from 30 healthy individuals and 50 RA patients for detecting the expression of miR-342-3p, and its correlation with the clinical indicators RF, ESR, anti-CCP, hs-CRP, C3, DAS-28, SAS, and SDS was analyzed. In RA-FLS cultures, the effect of transfection of miR-342-3p mimics and inhibitor on TNF-α-induced inflammatory response of the cells was evaluated by detecting the expressions of IL-1β, IL-6, IL-10, and TNF-α using ELISA. CCK8 assay and Transwell assay were used for detecting the changes in cell viability and migration ability of the synovial cells.

RESULTS

In RA patients, the expression level of miR-342-3p was significantly lowered in the PBMCs (P < 0.05) with an area under the ROC curve of 97.53% and showed inverse correlations with RF (r=-0.321), ESR(r=-0.284), anti-CCP (r=-0.355), hs-CRP (r=-0.320), C3 (r=-0.294), DAS-28 (r=-0.395), SAS (r=-0.366), and SDS (r=-0.397) (all P < 0.05); a low expression of miR-342-3p was strongly associated with elevated levels of anti-CCP, DAS-28, SDS, and SAS (all with a rule support greater than 85%, confidence greater than 88%, and lift greater than 1). In cultured RA-FLS, TNF-α stimulation significantly increased the cell viability (P < 0.05), upregulated the expressions of IL-1β, IL-6, and TNF-α, and lowered the expression of IL-10 (P < 0.05). These changes were significantly suppressed by transfection of the cells with miR-342-3p mimics (P < 0.05) but enhanced by transfection with miR-342-3p inhibitor (P < 0.05).

CONCLUSION

The expression of miR-342-3p is decreased in the PBMCs of RA patients. A lowered expression of miR-342-3p contributes to the pathogenesis of RA by promoting inflammatory responses and migration of RA-FLS.

CircPTTG1IP knockdown suppresses rheumatoid arthritis progression by targeting miR-431-5p/FSTL1 axis

BACKGROUND

It is observed that circular RNA (circRNA) PTTG1 interacting protein (circPTTG1IP) level is notably up-regulated in rheumatoid arthritis (RA) patients by previous study. However, its precise role and working mechanism in RA pathology remain to be clarified.

METHODS AND RESULTS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were carried out to examine RNA and protein expression. Cell proliferation was analyzed by colony formation assay and 5-Ethynyl-2'-deoxyuridine (EdU) assay. Cell motility was assessed by transwell assays and wound healing assay. Flow cytometry (FCM) analysis was performed to assess cell apoptosis rate. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA-pull down assays were conducted to confirm the interaction between microRNA-431-5p (miR-431-5p) and circPTTG1IP or follistatin like 1 (FSTL1). CircPTTG1IP expression was up-regulated in the synovial tissues of RA patients and RA patients-derived fibroblast-like synoviocytes (RA-FLS). CircPTTG1IP absence suppressed the proliferation, migration, and invasion and induced the apoptosis of RA-FLS. CircPTTG1IP negatively regulated the expression of miR-431-5p by directly binding to it in RA-FLS. CircPTTG1IP interference-mediated effects in RA-FLS were largely counteracted by the silence of miR-431-5p. miR-431-5p directly interacted with the 3' untranslated region (3'UTR) of FSTL1. FSTL1 overexpression largely overturned miR-431-5p accumulation-mediated effects in RA-FLS. CircPTTG1IP positively regulated FSTL1 expression by sponging miR-431-5p in RA-FLS.

CONCLUSION

CircPTTG1IP absence suppressed RA progression through mediating miR-431-5p/FSTL1 signaling cascade.

Overexpression of long noncoding RNA LINC00638 inhibits inflammation and oxidative stress in rheumatoid arthritis fibroblast-like synoviocytes by regulating the Nrf2/HO-1 pathway

Background

Abnormal expression of long noncoding RNAs (lncRNAs) is involved in several autoimmune diseases including rheumatoid arthritis (RA). In this study, we intended to explore the expression of lncRNA LINC00638 in RA and its potential mechanism of action related to inflammation and oxidative stress.

Methods

The level of LINC00638 in the peripheral blood mononuclear cells (PBMCs) obtained from 45 RA patients and 30 normal controls was analyzed and its correlation with clinical indicators was investigated. In vitro, we used tumor necrosis factor‐α to stimulate fibroblast‐like synoviocytes (FLS) of RA patients for cell based experiments. Subsequently, the overexpressed plasmid and small interfering RNA of LINC00638 were designed. Furthermore, we further analyzed the potential effects of LINC00638 on the proliferation and migration of RA‐FLS and the nuclear factor erythrocyte derived 2 related factor 2 (Nrf2)/heme oxygenase 1 (HO‐1) pathway.

Results

LINC00638 expression was found to be significantly decreased in PBMCs of RA patients, and it was negatively correlated with erythrocyte sedimentation rate, interleukin (IL)‐17, reactive oxygen species (ROS), and disease activity scores for 28 joints (DAS28). Overexpression of LINC00638 activated the Nrf2/HO‐1 pathway, markedly decreased the expressions of IL‐6, IL‐17, IL‐23, ROS, as well as malondialdehyde, increased the total antioxidant capacity, and attenuated the proliferation and migration of RA‐FLS, while silencing of LINC00638 reversed these manifestations.

Conclusions

LINC00638 was found to be expressed at low levels in RA patients and was associated with immune inflammation, oxidative stress, and disease activity. Overexpression of LINC00638 can reduce the proliferation as well as migration of RA‐FLS, and activate the Nrf2/HO‐1 pathway to inhibit the inflammation and oxidative stress.

Expression of LINC00638 in rheumatoid arthritis patients with damp-heat obstruction syndrome and the regulatory mechanisms for inflammation and oxidative stress

OBJECTIVES

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and joint destruction. Both inflammatory response and oxidative stress contribute to the pathogenesis of RA. Oxidative damage can induce and aggravate the imbalance of immune inflammation and promote cell and tissue damage. In this study, the expression of long non-coding RNA (lncRNA) LINC00638 in peripheral blood of patients with RA damp-heat arthralgia syndrome was observed, and the correlation between LINC00638 and disease activity, immune inflammation and oxidative stress indicator was investigated. Subsequently, the mechanisms for LINC00638 in regulating the inflammatory response and oxidative stress in RA fibroblast-like synoviocyte (FLS) under the condition of overexpression and interference were further explored.

METHODS

In this study, 48 RA patients with damp-heat arthralgia syndrome and 27 normal healthy subjects, who came from Department of Rheumatology, First Affiliated Hospital of Anhui University of Chinese Medicine, were included; and they were divided into a RA group and a control group. The expression of LINC00638 in peripheral blood mononuclear cells (PBMC) from the subjects was detected by real-time PCR. Enzyme linked immunosorbent assay (ELISA) was used to detect serum interleukin (IL)-10, IL-17, tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2) expression. Spearman method was used to study the relationship between LINC00638 and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide antibody (anti-CCP), and to observe the relation between LINC00638 and the Disease Activity Score of 28 Joint (DAS28), Quantitative Score of Damp Heat Syndrome, Visual Analogue Scale (VAS), Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS). RA-FLS was induced by RA-PBMC, and the RA in vitro cell experimental model was established. LINC00638 overexpression plasmid and small interfering RNA (siRNA) were constructed and transfected into RA-FLS. The cell experiments were divided into 4 groups: a pcDNA3. 1- control group, a pcDNA3.1-LINC00638 group, a siRNA-control group, and a siRNA-LINC00638 group. The transfection efficiency of overexpression plasmid and siRNA was detected by real-time PCR, the expression of TNF-α and IL-10 was detected by ELISA, and the expression of antioxidant proteins HO-1 and SOD2 was detected by immunofluorescence.

RESULTS

Compared with the control group, the expression of LINC00638 in the RA group was lower (P<0.01). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve of LINC00638 was 0.9271. The DAS28 in RA group was 5.70 (5.40-6.50), the Quantitative Score of Damp-heat Syndrome was 20.0 (17.0-23.0), and the VAS score was 7.0 (6.3-8.0). Compared with the control group, the ESR, CRP, RF, anti-CCP, SAS and SDS scores in the RA group were significantly increased (all P<0.01). Spearman correlation analysis showed that: LINC00638 was negatively correlated with ESR (r=-0.532, P<0.01), CRP (r=-0.367, P<0.05), TNF-α (r=-0.375, P<0.01), MDA (r= -0.295, P<0.05), DAS28 (r=-0.450, P<0.01), and which was positively correlated with SOD2 (r=0.370, P<0.05). After the induction of RA-FLS, the expression level of LINC00638 was significantly decreased (P<0.01), indicating that the stimulation of PBMC could effectively reduce the expression of LINC00638 in RA-FLS, so the experimental model of RA-FLS-induced by PBMC was utilized. Compared with the pcDNA3.1-control group, the expressions of LINC00638, IL-10, SOD2, and HO-1 in the pcDNA3.1-LINC00638 group were significantly increased (all P<0.01), and the expression of TNF-α was decreased (P<0.01). Compared with siRNA-control group, LINC00638, IL-10, SOD2 and HO-1 in the siRNA-LINC00638 group were significantly decreased (all P<0.01), and TNF-α was significantly increased (P<0.01).

CONCLUSIONS

LINC00638 is down-regulated in the peripheral blood of RA patients with damp-heat arthralgia syndrome, which is correlated with disease activity, immune inflammation and oxidative stress. Overexpression of LINC00638 can down-regulate pro-inflammatory factors, up-regulate anti-inflammatory factors, and increase antioxidant enzyme activity, thereby improving inflammation and oxidative stress in RA. LINC00638 is the differential lncRNA obtained by the research group's previous high-throughput sequencing of the whole transcriptome of peripheral blood PBMCs in RA patients and validation of clinical samples. In order to deepen the molecular biology research of this gene, the microRNA and mRNA targeted by LINC00638 can be further studied from the perspective of competing endogenous RNAs.

Tumor Mutation Burden-Associated LINC00638/miR-4732-3p/ULBP1 Axis Promotes Immune Escape via PD-L1 in Hepatocellular Carcinoma

Tumor mutation burden (TMB) is associated with immune infiltration, while its underlying mechanism in hepatocellular carcinoma (HCC) remains unclear. A long noncoding RNA (lncRNA)-related competitive endogenous RNA (ceRNA) network can regulate various tumor behaviors, and research about its correlation with TMB and immune infiltration is warranted. Data were downloaded from TCGA and ArrayExpress databases. Cox analysis and machine learning algorithms were employed to establish a lncRNA-based prognostic model for HCC. We then developed a nomogram model to predict overall survival and odds of death for HCC patients. The association of this prognostic model with TMB and immune infiltration was also analyzed. In addition, a ceRNA network was constructed by using DIANA-LncBasev2 and the starBase database and verified by luciferase reporter and colocalization analysis. Multiplex immunofluorescence was applied to determine the correlation between ULBP1 and PD-L1. An eight-lncRNA (SLC25A30-AS1, HPN-AS1, LINC00607, USP2-AS1, HCG20, LINC00638, MKLN1-AS and LINC00652) prognostic score model was constructed for HCC, which was highly associated with TMB and immune infiltration. Next, we constructed a ceRNA network, LINC00638/miR-4732-3p/ULBP1, that may be responsible for NK cell infiltration in HCC with high TMB. However, patients with high ULBP1 possessed a poorer prognosis. Using multiplex immunofluorescence, we found a significant correlation between ULBP1 and PD-L1 in HCC, and patients with high ULBP1 and PD-L1 had the worst prognosis. In brief, the eight-lncRNA model is a reliable tool to predict the prognosis of HCC patients. The LINC00638/miR-4732-3p/ULBP1 axis may regulate immune escape via PD-L1 in HCC with high TMB.

Circ_0003972 Promotes the Proliferation and Inflammation of Fibroblast-like Synovial Cells in Rheumatoid Arthritis through Regulation of the miR-654-5p/FZD4 Axis

BACKGROUND

Circular RNAs (circRNAs) have been shown to play an important role in rheumatoid arthritis (RA) progression. This study aims to explore the role and mechanism of circ_0003972 in RA progression.

METHODS

Quantitative real-time PCR was used to determine gene expression. The proliferation and apoptosis of human RA fibroblast-like synovial (HFLS-RA) cells were measured using cell counting kit 8 assay, EdU staining and flow cytometry. Western blot analysis was performed to measure protein expression, and ELISA assay was used to examine the concentrations of inflammation factors. The interaction between miR-654-5p and circ_0003972 or FZD4 was confirmed by dual-luciferase reporter assay and RIP assay.

RESULTS

Circ_0003972 was highly expressed in RA patients and HFLS-RA cells. Circ_0003972 knockdown inhibited the proliferation, inflammation, while promoted the apoptosis of TNFα-induced HFLS-RA cells. MiR-654-5p was downregulated in RA patients and HFLS-RA cells, and it could be sponged by circ_0003972. MiR-654-5p inhibitor reversed the effect of circ_0003972 silencing on the proliferation, inflammation, and apoptosis of TNFα-induced HFLS-RA cells. Frizzled-4 (FZD4) could be targeted by miR-654-5p, and its expression was positively regulated by circ_0003972. Furthermore, FZD4 overexpression also reversed the effects of miR-654-5p on proliferation, inflammation and apoptosis in TNFα-induced HFLS-RA cells.

CONCLUSION

Our data suggested that circ_0003972 might promote the proliferation and inflammation of HFLS-RA cells to accelerate RA progression via regulating miR-654-5p/FZD4.

[The low expression of long non-coding RNA Linc00638 contributes to rheumatoid arthritis progression by regulating inflammation and oxidative stress]

OBJECTIVE

To investigate the expression of long non-coding RNA (lncRNA) Linc00638 in rheumatoid arthritis (RA) and its regulatory role in inflammation and oxidative stress of synovial fibroblasts in RA patients (RA-FLS).

METHODS

Peripheral blood mononuclear cells (PBMCs) were collected from 20 healthy individuals and 35 RA patients for detecting the expression of Linc00638 using RT-qPCR to analyze the correlation of Linc00638 expression with the clinical indicators of RA patients. A Linc00638 overexpression plasmid and siRNA targeting Linc00638 were transfected into RA-FLS, and the changes in cell viability was observed using CCK8 assay; the changes in the expression levels of interleukin-4 (IL-4), IL-6, reactive oxygen species (ROS) and superoxide dismutase (SOD) in the supernatant were detected using ELISA.

RESULTS

Compared with the healthy control subjects, RA patients had significantly increased ESR, CRP, RF, anti-CCP, IgA, and C4 levels (P < 0.05) and significantly decreased Linc00638 expression in the PBMCs (P < 0.01). The area under the receiver-operating characteristic (ROC) curve of Linc00638 was 91.86% with the best cut-off value of 0.74 for diagnosis of RA. Spearman correlation analysis showed that Linc00638 expression level was negatively correlated with age, course of disease, DAS28, ESR, CRP, RF and anti-CCP, and positively correlated with IL-4 and SOD levels (P < 0.05). Association rule analysis showed that a decreased Linc00638 expression was strongly correlated with an increase of age (>60 years), a longer disease course (>10 years), elevated levels of ESR, RF and anti-CCP, and decreased levels of IL-4 and SOD. In RA-FLS, overexpression of Linc00638 significantly inhibited while Linc00638 interference obviously enhanced the cell viability. Over-expression of Linc00638 also significantly increased the levels of IL-4 and SOD (P < 0.05) and decreased the expressions of IL-6 and ROS (P < 0.05), while interference of Linc00638 produced the opposite effects in the cells (P < 0.05).

CONCLUSION

RA patients have low expression levels of Linc00638, which may participate in disease progression by regulating inflammation and oxidative stress.