American Diabetes Association
Revised_Suppl.results._revision2_final.pdf (772.65 kB)

Regulation of monocyte activation by PPARα through interaction with the cGAS-STING pathway

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posted on 2023-04-14, 16:28 authored by Lijie Dong, Rui Cheng, Xiang Ma, Wentao Liang, Yaru Hong, Hui Li, Kelu Zhou, Yanhong Du, Yusuke Takahashi, Xiaomin Zhang, Xiaorong Li, Jian-xing Ma


Monocyte activation plays an important role in diabetic complications such as diabetic retinopathy (DR). However, the regulation of monocyte activation in diabetes remains elusive. Fenofibrate, an agonist of peroxisome proliferator-activated receptor-alpha (PPARα), has shown robust therapeutic effects on DR in type 2 diabetic patients. Here we found that PPARα levels were significantly down-regulated in monocytes from diabetic patients and animal models, correlating with monocyte activation. Fenofibrate attenuated monocyte activation in diabetes, while PPARα knock-out alone induced monocyte activation. Furthermore, monocyte-specific PPARα overexpression ameliorated, while monocyte-specific PPARα knock-out aggravated, monocyte activation in diabetes. PPARα knock-out impaired mitochondrial function, while increasing glycolysis in monocytes. PPARα knock-out increased cytosolic mitochondrial DNA release and activation of the cGAS-STING pathway in monocytes under diabetic conditions. STING knock-out or STING inhibitor attenuated monocyte activation induced by diabetes or by PPARα knock-out. These observations suggest that PPARα negatively regulates monocyte activation through metabolic reprogramming and interaction with the cGAS-STING pathway.


LJD received a funding from a National Natural Science Foundation of China grant (NSFC: 81570872). JXM has received grants from NIH (EY019309, EY033330, EY030472, EY012231, EY028949, EY032930, EY032931), This study was also supported by the Diabetic Animal Core and Histology and Image Core of diabetic COBRE (GM122744) and the Vision Core supported by NEI P30 (EY021725).