Dynamin-Related Protein 1 Is Involved in Mitochondrial Damage, Defective Mitophagy, and NLRP3 Inflammasome Activation Induced by MSU Crystals

Abstract

Excessive generation of reactive oxygen species (ROS) has great impacts on MSU crystal-induced inflammation. Drp1-dependent mitochondrial fission is closely associated with mitochondrial ROS levels. However, whether Drp1 signaling contributes to MSU crystal-induced inflammation remains unclear. Mice bone marrow-derived macrophages (BMDMs) were primed with LPS and then stimulated with MSU suspensions for 12 h. The protein levels associated with mitochondrial dynamics, oxidative stress, and mitophagy were detected by Western blot. BMDMs were loaded with MitoTracker Green probe to detect mitochondrial morphology. To measure mitochondrial reactive oxygen species (ROS) and total ROS levels, cells were loaded, respectively, with MitoSOX and DHE probes. The effects of Mito-TEMPO, an antioxidant that targets the mitochondria or DRP1 inhibitor (Mdivi-1) on MSU crystal-induced peritonitis and arthritis mouse models, were evaluated. Our study revealed that MSU crystal stimulation resulted in elevation of mitochondrial fragmentation of BMDMs. Treatment with Mito-TEMPO or Drp1 knockdown significantly ameliorated the mitochondrial damage induced by MSU crystals. BMDMs exposure to MSU crystals increased the expression of auto/mitophagy marker proteins and promoted the fusion of mitophagosomes with lysosomes, leading to accumulation of mitolysosomes. Drp1 knockdown alleviated defective mitophagy and activation of the NLRP3 inflammasome in MSU crystal-treated BMDMs. This study indicates that there is crosstalk between mitochondrial ROS and Drp1 signaling in MSU crystal-induced inflammation. Drp1 signaling is involved in MSU crystal-induced mitochondrial damage, impaired mitophagy and NLRP3 inflammasome activation.

Exposing kinetic disparities between inflammasome readouts using time-resolved analysis

“…In order to provide time-resolved data of ASC-speck formation spanning the full duration of speck formation, the number of ASC-GFP-specks in PMA-differentiated and LPS-primed THP-1-ASC-GFP cell populations activated with either ATP, MSU or nigericin was quantified at multiple time points using fluorescence microscopy. The used concentrations of ATP [ 14 , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] ], MSU [ [31] , [32] , [33] , [34] , [35] , [36] ] and nigericin [ 21 , 22 , 25 , 27 , [37] , [38] , [39] , [40] ] are commonly found in the literature for NLRP3 activation in THP-1 and other cell models. Untreated controls were also imaged to investigate any potential effects of imaging ( Fig.…”

NLRP3 inflammasome and pyroptosis in cardiovascular diseases and exercise intervention

“…However, the Azam Ahmadi team's work demonstrates exercise preconditioning (EP) in a short period did not affect Drp1 (Ahmadi et al, 2022), while inhibiting NLRP3 expression. This finding indicates that EP in a short period is required to inhibit NLRP3 inflammasome independently of Drp1; the reduction of NLRP3 can occur through other mechanisms (Jiang et al, 2022).…”

“…Azam Ahmadi et al, 2022 found HIIT can effectively decrease heart injury and NLRP3 expression in rats with MI. Interestingly, dynamin-related protein 1 (Drp1), an essential mitochondrial fission protein, can activate NLRP3 inflammasome through ROS generation after MI (Ahmadi et al, 2022;Jiang et al, 2022). However, the Azam Ahmadi team's work demonstrates exercise preconditioning (EP) in a short period did not affect Drp1 (Ahmadi et al, 2022), while inhibiting NLRP3 expression.…”

KAT8 functions in redox homeostasis and mitochondrial dynamics during mouse oocyte meiosis progression

“…Dysfunctional and damaged mitochondria are a major source of ROS. 50 KAT8 can promote NADPH oxidase (NOX) in RAW 264.7 cells, ultimately leading to the overproduction and accumulation of ROS. 51 Numerous components of the cell can be oxidized by excessive ROS, including DNA, RNA, proteins, and lipids, thereby disturbing multiple biologic events.…”

“…Dysfunctional and damaged mitochondria are a major source of ROS 50 . KAT8 can promote NADPH oxidase (NOX) in RAW 264.7 cells, ultimately leading to the overproduction and accumulation of ROS 51 .…”