Fig 2: Functional role of circ_001653 in LPS-induced HK-2 cells. (A) Expression of circ_001653 in HK-2 cells after transfection with sh-circ_001653-1/2/3 and negative control sh-NC for 48 h as measured by qRT-PCR. To explore the effects of circ_001653 knockdown on LPS-induced HK-2 cells, HK-2 cells were treated with LPS (10 µg/mL) for 24 h alone or after transfection with sh-NC or sh-circ_001653 for 48 h. HK-2 cells without LPS treatment were used as the control (Ctrl) group. (B) TUNEL assay was performed to measure apoptosis of HK-2 cells in each group. (C) EdU assay was used to detect the proliferation of HK-2 cells after the indicated treatment. (D) Relative fluorescence level of ROS in HK-2 cells from corresponding groups detected by DCFH-DA staining. (E) MDA, (F) SOD, (G) GSH activities, and (H) CAT levels in the supernatant of HK-2 cells in indicated groups were detected using the corresponding kits. (I) The contents of IL-1β, IL-6, and TNF-α in the supernatant of HK-2 cells from corresponding groups were detected by ELISA. **P < 0.01, ***P < 0.001. Ctrl: Control; LPS: lipopolysaccharide; DAPI: 4’,6-diamidino-2-phenylindole; TUNEL, terminal deoxynucleotidyl transferase dUTP nick-end labeling; EdU, Ethynyl-2ʹ-Deoxyuridine; ROS: reactive oxygen species; MDA: malondialdehyde; SOD: superoxide dismutase; GSH: glutathione; CAT: catalase; IL-1β: Interleukin (IL)-1beta; IL-6: Interleukin (IL)-6; TNF-α: tumor necrosis factor (TNF)-alpha; ELISA: Enzyme-Linked Immunosorbent Assay

Fig 3: Circ_001653 inhibition alleviates renal dysfunction, oxidative stress, and inflammatory response in the CLP-induced SA-AKI rat model. Wistar rats were divided into the sham, CLP + sh-NC, and CLP + sh-circ_001653 groups (n = 6 per group). Rats in the CLP + sh-NC group or CLP + sh-circ_001653 group received ceacal ligation and puncture. The rats received injections of adenovirus carrying sh-NC or sh-circ_001653 via the tail vein. Rats in the sham group received caecum exposure without ligation. (A) qRT-PCR was performed to measure the relative expression level of circ_001653 in kidney tissues in indicated groups. (B) H&E staining was performed to evaluate the pathological morphology of renal tissues in indicated groups (left panel). A semi-quantitative histopathological score of renal tissue on a scale of 0-5 based on corresponding images (Right panel). Levels of (C) BUN and (D) sCr in serum from corresponding groups were detected using corresponding kits. Levels of urinary (E) NGAL and (F) KIM-1 were detected by ELISA. (G) Relative fluorescence levels of ROS in kidney tissues were detected by DCFH-DA staining. (H) Serum MDA levels in indicated groups were measured using the corresponding kit. Serum (I) SOD, (J) GSH activities, and (K) CAT levels in indicated groups were measured using the corresponding kits. Relative mRNA expression levels of (L) IL‐1β, (M) IL‐6, and (N) TNF‐α in kidney tissues were measured with quantitative PCR. (O) The serum levels of IL-1β, IL-6, and TNF-α in indicated groups were detected by ELISA. ***P < 0.001. CLP: cecal ligation and puncture; H&E: hematoxylin and eosin; BUN: blood urea nitrogen; sCr: serum creatinine; NGAL: Neutrophil gelatinase-associated lipocalin; KIM-1: Kidney Injury Molecule-1; MDA: malondialdehyde; SOD: superoxide dismutase; GSH: glutathione; CAT: catalase; IL-1β: Interleukin (IL)-1beta; IL-6: Interleukin (IL)-6; TNF-α: tumor necrosis factor (TNF)-alpha; ELISA: Enzyme-Linked Immunosorbent Assay