Gasdermin D Mediates Inflammation-Induced Defects in Reverse Cholesterol Transport and Promotes Atherosclerosis

Abstract

Activation of inflammasomes, such as Nlrp3 and AIM2, can exacerbate atherosclerosis in mice and humans. Gasdermin D (GsdmD) serves as a final executor of inflammasome activity, by generating membrane pores for the release of mature Interleukin-1beta (IL-1β). Inflammation dampens reverse cholesterol transport (RCT) and promotes atherogenesis, while anti-IL-1β antibodies were shown to reduce cardiovascular disease in humans. Though Nlrp3/AIM2 and IL-1β nexus is an emerging atherogenic pathway, the direct role of GsdmD in atherosclerosis is not yet fully clear. Here, we used in vivo Nlrp3 inflammasome activation to show that the GsdmD–/– mice release ∼80% less IL-1β vs. Wild type (WT) mice. The GsdmD–/– macrophages were more resistant to Nlrp3 inflammasome mediated reduction in cholesterol efflux, showing ∼26% decrease vs. ∼60% reduction in WT macrophages. GsdmD expression in macrophages exacerbated foam cell formation in an IL-1β dependent fashion. The GsdmD–/– mice were resistant to Nlrp3 inflammasome mediated defect in RCT, with ∼32% reduction in plasma RCT vs. ∼57% reduction in WT mice, ∼17% reduction in RCT to liver vs. 42% in WT mice, and ∼37% decrease in RCT to feces vs. ∼61% in WT mice. The LDLr antisense oligonucleotides (ASO) induced hyperlipidemic mouse model showed the role of GsdmD in promoting atherosclerosis. The GsdmD–/– mice exhibit ∼42% decreased atherosclerotic lesion area in females and ∼33% decreased lesion area in males vs. WT mice. The atherosclerotic plaque-bearing sections stained positive for the cleaved N-terminal fragment of GsdmD, indicating cleavage of GsdmD in atherosclerotic plaques. Our data show that GsdmD mediates inflammation-induced defects in RCT and promotes atherosclerosis.

Relationship between Brain Metabolic Disorders and Cognitive Impairment: LDL Receptor Defect

“…The complex induces gasdermin D (GSDMD)-mediated lytic apoptosis (pyroptosis) by increasing the levels of active caspase-1. Pyroptosis, a programmed cell death process, is mediated by a pore formed by the binding of GSDMD N-terminal fragments cleaved by active caspase-1 to the plasma membrane, inducing the release of inflammatory cytokines such as IL-1β and IL-18, leading to neuronal pyroptosis [ 96 , 97 , 98 , 99 , 100 ]. Additionally, interleukin-10 (IL-10), an anti-inflammatory cytokine, inhibits the activity of inflammatory cytokines by inhibiting TLR induction [ 93 ].…”

Gasdermin D Deficiency Limits the Transition of Atherosclerotic Plaques to an Inflammatory Phenotype in ApoE Knock-Out Mice

“…Thus, Gsdmd −/− BMDMs are resistant to canonical pyroptosis induction, albeit they switch to another type of cell death that is characterized by DNA fragmentation, strongly suggestive of apoptosis. A switch from pyroptosis to apoptosis is further supported by the observation that caspase 1 p10 is upregulated in LPS/nigericin-treated Gsdmd −/− BMDMs, and not in Gsdmd +/+ controls, and may act in a pro-apoptotic manner in the absence of GSDMD [39,40,45].…”

“…Accordingly, in vitro TUNEL positivity and levels of pro-apoptotic caspase 1 p10 were increased in Gsdmd −/− BMDMs while PI positivity did not increase. Similarly, Opoku and colleagues recently reported increased apoptosis, characterized by phosphatidyl serine exposure on the cell surface, when pyroptosis was defective in Gsdmd −/− macrophages [45]. Importantly, a switch to apoptosis, which is non-lytic and non-inflammatory (in contrast to pyroptosis), will limit plaque progression, inflammation, and destabilization and thus, is regarded to be atheroprotective at this stage of atherosclerosis in ApoE −/− mice.…”

“…Previous studies have demonstrated that GSDMD, NT-GSDMD, and Gsdmd mRNA are upregulated in aortas of hyperlipidemic mice and in LPS/oxLDL-treated mouse peritoneal macrophages [30]. Moreover, the expression of NT-GSDMD is increased in plaques of LDLr −/− mice [45]. Gsdmd mRNA is also upregulated in peripheral blood monocytes of atherosclerotic patients [30].…”

“…Of note, the authors also reported a decrease in lipid burden and plaque size in the aorta and aortic valve when GSDMD expression was suppressed, however, only a limited number of mice was included and preliminary data were reported [30]. Another study reported a decreased lesion area in the aortic root of LDLr antisense oligonucleotide-treated Gsdmd −/− mice compared to Gsdmd +/+ controls, which was attributed to decreased IL-1β release resulting in decreased foam cell formation and ATP release in plasma [45]. Importantly, experimental differences such as a longer period of feeding WD in the present study, evaluation of different vascular sites, and the use of different genetic models make comparison with these studies difficult.…”