The significance of circular RNA hsa_circ_0006156 expression in peripheral blood of SLE patients and its effect on proliferation and apoptosis of Raji cells

Objective: To investigate the effect of hsa_circ_0006156 on the proliferation and apoptosis of Raji cells and its role in the occurrence and development of systemic lupus erythematosus (SLE). Methods: A total of 55 SLE patients (SLE group) admitted to the Department of Dermatology and Venereal Diseases, the First Affiliated Hospital of Guangxi Medical University from September 2021 to September 2023 were collected, and 40 healthy controls were taken as the control group (HC group). Peripheral blood mononuclear cells (PBMC) and CD20⁺B lymphocytes were isolated. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of hsa_circ_0006156, and receiver operating characteristic (ROC) curve was used to analyze the diagnostic efficacy of hsa_circ_0006156. Taking Raji cells as the research object, the hsa_circ_0006156 overexpression model was constructed by lentivirus. The cells were divided into hsa_circ_0006156 overexpression group (OE group), negative control group (NC group) transfected with empty viral vector, and blank control group (control group). CCK8 assay was used to detect the cell absorbance of 450 nm at 0 h, 6 h, 12 h, 18 h, 24 h, 30, 36 h, and the proliferation rate of OE group and NC group was calculated.Western blotting was used to detect the expression levels of Bcl-2 and cleaved caspase-3 apoptotic proteins in each group. Results: Compared with the HC group, the expression of hsa_circ_0006156 in PBMC and CD20⁺B lymphocytes in the SLE group was significantly decreased (P< 0.001). ROC curve analysis showed that the area under the ROC curve (AUC) of hsa_circ_0006156 distinguishing SLE and HC was 0.7873 (95% CI:0.6975-0.877; P< 0.001), sensitivity was 97.5%, specificity was 50.9%, and cut-off value for SLE diagnosis was less than 0.652. There was a significant difference in the expression of hsa_circ_0006156 between patients with no or mild activity and moderate to severe activity (P=0.0148). CCK8 assay showed that the proliferation of Raji cells in the OE group was significantly inhibited compared with the NC group at 36 h (P< 0.001). The results of western blotting showed that compared with the NC group and the control group, the expression level of Bcl-2 protein in the OE group was decreased, while the expression level of cleaved caspase-3 protein was increased (all P< 0.05). Conclusion: The hsa_circ_0006156 has certain diagnostic efficacy for SLE. It may affect the occurrence and development of SLE by regulating the proliferation and apoptosis of B cells.