Cellular FLICE-inhibitory protein (c-FLIP), an anti-apoptotic regulator, shows remarkable similarities to caspase-8, which plays a key role in the cleavage of gasdermin D (GSDMD). It has been reported that the oxygen-glucose deprivation/recovery (OGD/R) model and lipopolysaccharide (LPS)/adenosine triphosphate (ATP) treatment could induce inflammation and pyroptosis. However, the regulatory role of c-FLIP in the pyroptotic death of retinal neurons is unclear. In this study, we hypothesized that c-FLIP might regulate retinal neuronal pyroptosis by GSDMD cleavage. To investigate this hypothesis, we induced retinal neuronal damage in vitro (OGD/R and LPS/ATP) and in vivo (acute high intraocular pressure [aHIOP]). Our results demonstrated that the three injuries triggered the up-regulation of pyroptosis-related proteins, and c-FLIP could cleave GSDMD to generate a functional N-terminal (NT) domain of GSDMD, causing retinal neuronal pyroptosis. In addition, c-FLIP knockdown in vivo ameliorated the already established visual impairment mediated by acute IOP elevation. Taken together, these findings revealed that decreased c-FLIP expression protected against pyroptotic death of retinal neurons possibly by inhibiting GSDMD-NT generation. Therefore, c-FLIP might provide new insights into the pathogenesis of pyroptosis-related diseases and help to elucidate new therapeutic targets and potential treatment strategies.

细胞 FLICE 抑制蛋白 (c-FLIP) 是一种抗凋亡调节剂，与 caspase-8 具有显着的相似性，后者在 Gasdermin D (GSDMD) 的裂解中起关键作用。据报道，氧-葡萄糖剥夺/恢复（OGD/R）模型和脂多糖（LPS）/三磷酸腺苷（ATP）治疗可诱导炎症和细胞焦亡。然而，c-FLIP 在视网膜神经元焦亡中的调节作用尚不清楚。在这项研究中，我们假设 c-FLIP 可能通过 GSDMD 裂解调节视网膜神经元焦亡。为了研究这一假设，我们在体外（OGD/R 和 LPS/ATP）和体内诱导了视网膜神经元损伤（急性高眼压 [aHIOP]）。我们的结果表明，这三种损伤触发了焦亡相关蛋白的上调，c-FLIP 可以切割 GSDMD 以产生 GSDMD 的功能性 N 端 (NT) 域，导致视网膜神经元焦亡。此外，体内c-FLIP敲低改善了由急性眼压升高介导的已经建立的视力障碍。综上所述，这些发现表明，降低的 c-FLIP 表达可能通过抑制 GSDMD-NT 生成来防止视网膜神经元的焦亡。因此，c-FLIP 可能为焦亡相关疾病的发病机制提供新的见解，并有助于阐明新的治疗靶点和潜在的治疗策略。