STING deficiency alleviates ferroptosis through FPN1 stabilization in diabetic kidney disease.

Ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, has known as one of the most significant pathological processes involved in diabetic kidney disease (DKD). Stimulator of interferon genes (STING) has been demonstrated its potential in regulating ferroptosis, but the regulatory role in DKD mice and underlying mechanisms haven't been illustrated. To elucidate whether and how STING regulates ferroptosis in DKD, we detected the influence of STING on diabetic-related ferroptosis in a diabetic model and in erastin-induced renal tubular epithelial cells (RTECs). Our study demonstrated that STING was abnormally activated and promoted ferroptosis in DKD. STING deficiency alleviated renal pathologic damages and disfunction in diabetic mice via alleviating ferroptosis and reducing oxidative stress. Mechanismly, STING inhibition was shown to improve ferroptosis and reduce oxidative stress in erastin-induced RTECs. The disruption of ferroportin1 (FPN1) on the basis of STING inhibition abolished the improvements in ferroptosis and promoted reactive oxygen species (ROS) generation. Further, STING inhibition alleviated ferroptosis via stabilizing FPN1 protein level by decreasing ubiquitinated FPN1 for proteasomal degradation. In conclusion, STING deficiency protected against diabetic renal injury via alleviating ferroptosis through stabilizing FPN1 and reducing oxidative stress, providing a possible potential approach for the treatment of DKD.

Efficacy and safety of sacubitril/valsartan after six months in patients with heart failure with reduced ejection fraction and asymptomatic hypotension.

BACKGROUND: It is not clear whether sacubitril/valsartan is beneficial for patients with heart failure (HF) with reduced ejection fraction (HFrEF) and low systolic blood pressure (SBP). This study aimed to investigate the efficacy and tolerability of sacubitril/valsartan in HFrEF patients with SBP < 100 mmHg. METHODS & RESULTS: An observational study was conducted on 117 patients, 40.2% of whom had SBP < 100 mmHg without symptomatic hypotension, and 59.8% of whom had SBP ≥ 100 mmHg in an optimized HF follow-up management system. At the 6-month follow-up, 52.4% of patients with SBP < 100 mmHg and 70.0% of those with SBP ≥ 100 mmHg successfully reached the target dosages of sacubitril/valsartan. A reduction in the concentration of N-terminal pro-B-type natriuretic peptide was similar between patients with SBP < 100 mmHg and SBP ≥ 100 mmHg (1627.5 pg/mL and 1340.1 pg/mL, respectively; P = 0.75). The effect of sacubitril/valsartan on left ventricular ejection fraction was observed in both SBP categories, with a 10.8% increase in patients with SBP < 100 mmHg (P < 0.001) and a 14.0% increase in patients with SBP ≥ 100 mmHg (P < 0.001). The effects of sacubitril/valsartan on SBP were statistically significant and inverse across both SBP categories (P = 0.001), with an increase of 7.5 mmHg in patients with SBP < 100 mmHg and a decrease of 11.5 mmHg in patients with SBP ≥ 100 mmHg. No statistically significant differences were observed between the two groups in terms of the occurrence of symptomatic hypotension, deteriorating renal function, hyperkalemia, angioedema, or stroke. CONCLUSIONS: Within an optimized HF follow-up management system, sacubitril/valsartan exhibited excellent tolerability and prompted left ventricular reverse remodeling in patients with HFrEF who presented asymptomatic hypotension.