Ginkgetin alleviates high glucose-evoked mesangial cell oxidative stress injury, inflammation, and extracellular matrix (ECM) deposition in an AMPK/mTOR-mediated autophagy axis

Abstract

Diabetic nephropathy constitutes the leading cause for end-stage kidney disease. Ginkgetin is a common natural non-toxic biflavone and fulfills pleiotropic pharmacological characterizations, such as anti-inflammation and kidney injury. Nevertheless, its efficacy in diabetic nephropathy remains elusive. Here, ginkgetin exhibited little cytotoxicity in glomerular mesangial cells. Of note, ginkgetin restrained high glucose (HG)-induced mesangial cell proliferation and oxidative stress by inhibiting ROS and malonaldehyde levels, but enhancing antioxidant SOD activity. Additionally, ginkgetin suppressed HG-evoked transcript and release of inflammatory cytokine TNF-α, IL-1β, and IL-6. Concomitantly, the increased extracellular matrix (ECM) deposition in HG-treated glomerular mesangial cells was attenuated by ginkgetin via decreasing expression of collagen IV, fibronectin, and laminin. Intriguingly, ginkgetin-restored HG-impaired autophagy; whereas blocking autophagy by its inhibitor 3-MA overturned ginkgetin function against HG-evoked mesangial cell dysfunction. Mechanistically, ginkgetin-mediated AMPK/mTOR axis accounted for HG-impaired autophagy. Importantly, blockage of AMPK signaling reversed ginkgetin-restored autophagy and its protective efficacy against HG-induced dysfunction in mesangial cells. Thus, these findings highlight that ginkgetin may attenuate HG-evoked mesangial cell hyperplasia, oxidative stress, inflammation, and ECM accumulation by activating AMPk/mTOR-mediated autophagy pathway. Therefore, ginkgetin may alleviate the progression of diabetic nephropathy by regulating glomerular mesangial cell dysfunction, supporting a promising therapeutic agent against diabetic nephropathy.

Keywords: ECM deposition; diabetic nephropathy; ginkgetin; inflammation; oxidative stress.