Propofol synergizes with circAPBB2 to protect against hypoxia/reoxygenation‐induced oxidative stress, inflammation, and apoptosis of human cardiomyocytes

Figures

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  Figure 1. CircAPBB2 expression was downregulated in H/R‐stimulated AC16 cells. (A) The schematic illustration showing the generation of circAPBB2 by the cyclization of the exons 7‐10 of the APBB2 gene. (B) CircAPBB2 expression was analyzed by qRT‐PCR in AC16 cells after treatment with hypoxia or normal oxygen (N = 3). (C) Subcellular fractionation location assay was performed to determine the location of circAPBB2 in AC16 cells (N = 3). (D) RNase R treatment assay was used to identify the structural stability of circAPBB2 (N = 3). (E) The efficiency of circAPBB2 overexpression was analyzed by qRT‐PCR in AC16 cells (N = 3). ***p < .001. Significant differences were determined using Student's t‐tests.

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  Figure 2. CircAPBB2 promoted DUSP14 expression by binding to miR‐18a‐5p. (A) The schematic illustration showing circAPBB2‐binding sites for miR‐18a‐5p. (B, C) Dual‐luciferase reporter assay and RIP assay were performed to determine the association of circAPBB2 and miR‐18a‐5p (N = 3). (D) The schematic diagram showing miR‐18a‐5p‐binding sites for DUSP14. (E) Dual‐luciferase reporter assay confirmed that miR‐18a‐5p targeted DUSP14 (N = 3). (F, G) RNA pull‐down assay and Western blot analysis assay were used to demonstrate that circAPBB2 regulated DUSP14 expression by binding to miR‐18a‐5p (N = 3). (H, I) MiR‐18a‐5p expression was analyzed by qRT‐PCR and DUSP14 protein expression was detected by Western blot analysis assay in AC16 cells after treatment with hypoxia or normal oxygen (N = 3). **p < .01 and ***p < .001. Significant differences were determined using Student's t‐tests in (B, C, E, H, I) and determined using one‐way analysis of variance with Tukey's test in (F and G).

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  Figure 3. CircAPBB2 overexpression ameliorated H/R‐induced myocardial cell injury by regulating miR‐18a‐5p. AC16 cells were divided into H/R group, H/R + OE‐circAPBB2 group, H/R + OE‐circAPBB2 group+miR‐18a‐5p group, with AC16 cells with normal treatment as controls. DUSP14 protein expression was analyzed by Western blot analysis assay (A) (N = 3). Cell viability was assessed by CCK‐8 assay (B) (N = 3). LDH, ROS and SOD levels were detected by commercial detection kits (C−E) (N = 3). TNF‐α and IL‐1β levels were quantified by ELISAs (F, G) (N = 3). Cell apoptosis was quantified by flow cytometry assay (H, I) (N = 3). Cleaved caspase 3, cleaved PARP and Bcl‐2 expression were detected by Western blot analysis (J, K) (N = 3). *p < .05, **p < .01 and ***p < .001. Significant differences were determined using one‐way analysis of variance with Tukey's test. Bcl‐2, B‐cell lymphoma‐2; CCK‐8, cell counting kit‐8; H/R, hypoxia/reoxygenation; IL‐1β, interleukin‐1β; LDH, Lactate dehydrogenase; ROS, reactive oxygen species; SOD, superoxide dismutase; TNF‐α, tumor necrosis factor‐α.

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  Figure 4. MiR‐18a‐5p depletion ameliorated H/R‐induced myocardial cell injury by regulating DUSP14. AC16 cells were divided into H/R group, H/R+anti‐miR‐18a‐5p group, H/R+anti‐miR‐18a‐5p+si‐DUSP14 group, with AC16 cells with normal treatment as controls. DUSP14 protein expression was analyzed by Western blot analysis assay (A) (N = 3). Cell viability was assessed by CCK‐8 assay (B) (N = 3). LDH, ROS, and SOD levels were detected by commercial detection kits (C‐E) (N = 3). TNF‐α and IL‐1β levels were quantified by ELISAs (F and G) (N = 3). Cell apoptosis was quantified by flow cytometry assay (H and I) (N = 3). Cleaved caspase 3, cleaved PARP and Bcl‐2 expression were detected by Western blot analysis (J, K) (N = 3). *p < .05, **p < .01 and ***p < .001. Significant differences were determined using one‐way analysis of variance with Tukey's test. Bcl‐2, B‐cell lymphoma‐2; CCK‐8, cell counting kit‐8; H/R, hypoxia/reoxygenation; IL‐1β, interleukin‐1β; LDH, Lactate dehydrogenase; ROS, reactive oxygen species; SOD, superoxide dismutase; TNF‐α, tumor necrosis factor‐α.

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  Figure 5. PPF treatment protected against H/R‐induced myocardial cell injury through miR‐18a‐5p. (A, B) The effects of PPF and H/R treatments on circAPBB2 and miR‐18a‐5p expression were analyzed by qRT‐PCR (N = 3). (C) The effects of PPF and H/R treatments on DUSP14 protein expression were analyzed by Western blot analysis assay (N = 3). AC16 cells were divided into H/R group, H/R + 150 μM PPF group, H/R + 150 μM PPF+miR‐18a‐5p group, with AC16 cells with normal treatment as controls. DUSP14 protein expression was analyzed by Western blot analysis assay (D) (N = 3). Cell viability was assessed by CCK‐8 assay (E) (N = 3). LDH, ROS and SOD levels were detected by commercial detection kits (F−G) (N = 3). TNF‐α and IL‐1β levels were quantified by ELISAs (I, J) (N = 3). Cell apoptosis was quantified by flow cytometry assay (K) (N = 3). Cleaved caspase 3, cleaved PARP and Bcl‐2 expression were detected by Western blot analysis (L) (N = 3). *p < .05, **p < .01 and ***p < .001. Significant differences were determined using one‐way analysis of variance with Tukey's test. Bcl‐2, B‐cell lymphoma‐2; CCK‐8, cell counting kit‐8; H/R, hypoxia/reoxygenation; IL‐1β, interleukin‐1β; LDH, Lactate…

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  Figure 6. PPF treatment enhanced circAPBB2‐mediated effects in H/R‐treated AC16 cells. AC16 cells were divided into H/R group, H/R + OE‐circAPBB2 group, H/R + OE‐circAPBB2 group+150 μM of PPF group, with AC16 cells with normal treatment as controls. CircAPBB2 and miR‐18a‐5p expression were analyzed by qRT‐PCR (A, B) (N = 3). DUSP14 protein expression was analyzed by Western blot analysis assay (C) (N = 3). Cell viability was assessed by CCK‐8 assay (D) (N = 3). LDH, ROS and SOD levels were detected by commercial detection kits (E‐G) (N = 3). TNF‐α and IL‐1β levels were quantified by ELISAs (H, I) (N = 3). Cell apoptosis was quantified by flow cytometry assay (J) (N = 3). Cleaved caspase 3, cleaved PARP and Bcl‐2 expression were detected by Western blot analysis (K) (N = 3). *p < .05, **p < .01 and ***p < .001. Significant differences were determined using one‐way analysis of variance with Tukey's test. Bcl‐2, B‐cell lymphoma‐2; CCK‐8, cell counting kit‐8; H/R, hypoxia/reoxygenation; IL‐1β, interleukin‐1β; LDH, Lactate dehydrogenase; ROS, reactive oxygen species; SOD, superoxide dismutase; TNF‐α, tumor necrosis factor‐α.