|Title||Critical Role of Cytosolic DNA and Its Sensing Adaptor STING in Aortic Degeneration, Dissection, and Rupture.|
|Publication Type||Journal Article|
|Year of Publication||2020|
|Authors||Luo, W, Wang, Y, Zhang, L, Ren, P, Zhang, C, Li, Y, Azares, AR, Zhang, M, Guo, J, Ghaghada, KB, Starosolski, ZA, Rajapakshe, K, Coarfa, C, Li, Y, Chen, R, Fujiwara, K, Abe, J-I, Coselli, JS, Milewicz, DM, LeMaire, SA, Shen, YH|
|Date Published||2020 Jan 07|
BACKGROUND: Sporadic aortic aneurysm and dissection (AAD), caused by progressive aortic smooth muscle cell (SMC) loss and extracellular matrix degradation, is a highly lethal condition. Identifying mechanisms that drive aortic degeneration is a crucial step in developing an effective pharmacologic treatment to prevent disease progression. Recent evidence has indicated that cytosolic DNA and abnormal activation of the cytosolic DNA sensing adaptor STING (stimulator of interferon genes) play a critical role in vascular inflammation and destruction. Here, we examined the involvement of this mechanism in aortic degeneration and sporadic AAD formation.
METHODS: The presence of cytosolic DNA in aortic cells and activation of the STING pathway were examined in aortic tissues from patients with sporadic ascending thoracic AAD. The role of STING in AAD development was evaluated in -deficient () mice in a sporadic AAD model induced by challenging mice with a combination of a high-fat diet and angiotensin II. We also examined the direct effects of STING on SMC death and macrophage activation in vitro.
RESULTS: In human sporadic AAD tissues, we observed the presence of cytosolic DNA in SMCs and macrophages and significant activation of the STING pathway. In the sporadic AAD model, mice showed significant reductions in challenge-induced aortic enlargement, dissection, and rupture in both the thoracic and abdominal aortic regions. Single-cell transcriptome analysis revealed that aortic challenge in wild-type mice induced the DNA damage response, the inflammatory response, dedifferentiation and cell death in SMCs, and matrix metalloproteinase expression in macrophages. These changes were attenuated in challenged mice. Mechanistically, nuclear and mitochondrial DNA damage in SMCs and the subsequent leak of DNA to the cytosol activated STING signaling, which induced cell death through apoptosis and necroptosis. In addition, DNA from damaged SMCs was engulfed by macrophages in which it activated STING and its target interferon regulatory factor 3, which directly induced matrix metalloproteinase-9 expression. We also found that pharmacologically inhibiting STING activation partially prevented AAD development.
CONCLUSIONS: Our findings indicate that the presence of cytosolic DNA and subsequent activation of cytosolic DNA sensing adaptor STING signaling represent a key mechanism in aortic degeneration and that targeting STING may prevent sporadic AAD development.
|PubMed Central ID||PMC6939474|
|Grant List||S10 OD018033 / OD / NIH HHS / United States |
R01 HL143359 / HL / NHLBI NIH HHS / United States
S10 OD025240 / OD / NIH HHS / United States
R01 HL130193 / HL / NHLBI NIH HHS / United States
R01 HL123346 / HL / NHLBI NIH HHS / United States
R01 HL127111 / HL / NHLBI NIH HHS / United States
S10 OD023469 / OD / NIH HHS / United States
R01 HL131980 / HL / NHLBI NIH HHS / United States
R01 HL118462 / HL / NHLBI NIH HHS / United States
P30 ES030285 / ES / NIEHS NIH HHS / United States
P30 CA125123 / CA / NCI NIH HHS / United States