Fig 2: Hsa_circ_0010957 modulates inflammatory cytokines secretion via miR-125b. (A) Overexpression or silencing efficiency of hsa_circ_0010957 or miR-125b in CD4+ T cells of SLE detected by reverse transcription-quantitative PCR. (B-D) IL-18, IL-6 and IL-17 levels detected in cell supernatant after CD4+ T cells were transfected with hsa_circ_0010957 siRNAs and miR-125b inhibitor. (E-J) Pearson's correlation analysis between hsa_circ_0010957 or miR-125b expressions in CD4+ T cells of SLE with inflammatory cytokines in serum of patients with SLE. Data are shown as mean ± SD *P<0.05. SLE, systemic lupus erythematosus; miR, microRNA; siRNA, small interfering RNA; NC, negative control; IL, interleukin.

Fig 3: Hsa_circ_0010957 regulates activation of STAT3 signaling via miR-125b. (A) Potential binding site and the mutant site of STAT3 3′UTR and miR-125b. (B) Luciferase assay showing overexpression of miR-125b decreased the luciferase activity of wide-type STAT3 3′UTR vector, while not the mutant vector. (C and D) STAT3 protein level after transfecting miR-125b mimics or inhibitor into CD4+ T cells of patients with SLE. (E) STAT3 and phosphorylated STAT3 protein level after transfecting hsa_circ_0010957 siRNA and miR-125b inhibitor into CD4+ T cells of patients with SLE. (F) Silence efficiency of STAT3 in CD4+ T cells of SLE detected by reverse transcription-quantitative PCR. (G-I) IL-18, IL-6 and IL-17 levels detected in cell supernatant after transfecting STAT3 siRNA into CD4+ T cells of patients with SLE. Data are shown as mean ± SD *P<0.05. NS, no significance; SLE, systemic lupus erythematosus; wt, wild-type; mut, mutant type; UTR, untranslated region; miR, microRNA; siRNA, small interfering RNA; NC, negative control; IL, interleukin.

Fig 4: NFAT1 activity was upregulated in CD4+ T cells from SLE patients and closely associated with increased HERV-E clone 4–1 mRNA expression. a Predicted wild-type (wt) binding sites and corresponding mutant (mut) sites of NFAT1 on HERV-E clone 4–1 5’LTR. b-e qRT-PCR and western-blot assays showing relative NFAT1 mRNA and protein expression in CD4+ cells from SLE patient with NFAT1 overexpression or knockdown. f Luciferase assays were performed in CD4+ T cells from SLE patient transfected with wt or mut luciferase reporter. Each luciferase activity was normalized to the value obtained in the cells transfected with vector (N = 3). g ChIP assay was used to assess NFAT1 binding site at HERV-E clone 4–1 5’LTR. h and i) Relative HERV-E clone 4–1 mRNA expression in CD4+ cells from SLE patient with NFAT1 overexpression or knockdown (N = 3). j and k Relative NFAT1 activity in CD4+ cells from SLE patients (N = 15) and HCs (N = 13) or active SLE patients (N = 12) and inactive SLE patients (N = 3) compared using the unpaired Student’s t test. l Correlation between relative NFAT1 activity and relative HERV-E clone 4–1 mRNA expression analyzed with Spearman’s analysis (N = 15). m and n CD4+ T cells from SLE patient were treated with TNF-α, IL-6, E2, LPS, UVB, HCQ or prednisolone in vitro. Relative NFAT1 activity (L) and relative HERV-E clone 4–1 mRNA expression (m) were detected. Data were represented as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001

Fig 5: Dissection progression was alleviated by blocking IL-6R and iron ions. (A) TCZ (intravenous injection; 1.0 mg/100 μL/day) inhibited IL-6R, and DFO (intraperitoneal injection; 200 mg/kg/day) chelated free iron ions (15 mice in control group; 20 mice in per dissection group to prevent accidental death). (B) Aortic dissection and rupture rate in mice. (C) Overall survival of mice during the experiment. (D) Gross anatomical views of aortas. (E) EVG staining of aortic sections. (F) Ultrasound images of ascending and descending aortas. (G) Change of ascending aorta (Left) and descending aorta (Right) diameters. (H) Multi-IF exhibited the protein levels of key genes. (I) IHC staining of aortic sections. (J) ROS staining of aortic tissues. (K, L) Contents of Fe2+ and MDA in mouse aortic tissues. (M, N) Contents of free iron ion and IL-6 in mouse serums. Data are presented as representative images or means ± SDs. *P < 0.05, **P < 0.01, ***P < 0.001, ns, not significant.