Chen Sida, Wen Ling, Wu Yumei, Xiao Shan, Lai Yuting, Ou Jintao, Shen Yan
Respiratory Department, Longgang Central Hospital, Shenzhen, China.
Yadi Sancun Community Health Service Center, Shenzhen Pingle Orthopaedic Hospital (Shenzhen Pingshan Traditional Chinese Medicine Hospital), Shenzhen, China.
PLoS One. 2024 Dec 20;19(12):e0314936. doi: 10.1371/journal.pone.0314936. eCollection 2024.
Pyroptosis is linked to the development of acute lung injury (ALI), and circular RNAs (circRNAs) play a role in ALI-related inflammation. However, the mechanisms by which circRNAs contribute to macrophage pyroptosis in ALI remain unclear. This study constructed an in vitro ALI model by inducing THP-1 cells with phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS). The expression and potential mechanism of circ-CARD8 in macrophage pyroptosis were then investigated. The interaction between circ-CARD8, hsa-miR-580-3p, and caspase recruitment domain family member 8 (CARD8) was confirmed through luciferase reporter assays and RNA-binding protein immunoprecipitation. Our data showed that circ-CARD8 was expressed at low levels. Meanwhile, the pyroptotic proteins caspase-1 and GSDMD, along with the secretion of chemokine (C-C motif) ligand 18 and interleukin 1 beta, were upregulated in the ALI cell model. Overexpression of circ-CARD8 reversed macrophage pyroptosis, whereas inhibition of circ-CARD8 promoted it. Furthermore, the expression of miR-580-3p, a downstream microRNA that binds to circ-CARD8, was reduced upon circ-CARD8 overexpression and increased following its inhibition. Additionally, overexpression of miR-580-3p suppressed the expression of CARD8, a downstream target of miR-580-3p, thereby promoting macrophage pyroptosis. The inhibition of miR-580-3p reversed the effect of circ-CARD8 silencing on macrophage pyroptosis and CARD8 expression. Therefore, our study confirms that the low expression of circ-CARD8 reduces the sponge adsorption of miR-580-3p, increasing its expression, which in turn targets and inhibits CARD8, ultimately promoting macrophage pyroptosis induced by LPS in THP-1 cells.
细胞焦亡与急性肺损伤（ALI）的发生发展有关，环状RNA（circRNAs）在ALI相关炎症中发挥作用。然而，circRNAs在ALI中促进巨噬细胞焦亡的机制仍不清楚。本研究通过用佛波酯12 - 肉豆蔻酸酯13 - 乙酸酯（PMA）和脂多糖（LPS）诱导THP - 1细胞构建了体外ALI模型。随后研究了circ - CARD8在巨噬细胞焦亡中的表达及潜在机制。通过荧光素酶报告基因检测和RNA结合蛋白免疫沉淀证实了circ - CARD8、hsa - miR - 580 - 3p和半胱天冬酶募集结构域家族成员8（CARD8）之间的相互作用。我们的数据表明circ - CARD8表达水平较低。同时，在ALI细胞模型中，细胞焦亡蛋白半胱天冬酶 - 1和Gasdermin D以及趋化因子（C - C基序）配体18和白细胞介素1β的分泌上调。circ - CARD8的过表达逆转了巨噬细胞焦亡，而circ - CARD8的抑制则促进了巨噬细胞焦亡。此外，与circ - CARD8结合的下游微小RNA miR - 580 - 3p的表达在circ - CARD8过表达时降低，在其抑制后升高。另外，miR - 580 - 3p的过表达抑制了miR - 580 - 3p的下游靶标CARD8的表达，从而促进巨噬细胞焦亡。miR - 580 - 3p的抑制逆转了circ - CARD8沉默对巨噬细胞焦亡和CARD8表达的影响。因此，我们的研究证实circ - CARD8的低表达降低了对miR - 580 - 3p的海绵吸附作用，增加了其表达，进而靶向并抑制CARD8，最终促进THP - 1细胞中LPS诱导的巨噬细胞焦亡。
