DEXMEDETOMIDINE AMELIORATES ACUTE BRAIN INJURY INDUCED BY MYOCARDIAL ISCHEMIA-REPERFUSION VIA UPREGULATING THE HIF-1 PATHWAY

Ciprofol Ameliorates Myocardial Ischemia/Reperfusion Injury by Inhibiting Ferroptosis Through Upregulating HIF-1α

Purpose

Ciprofol is a novel intravenous anesthetic that has been increasingly used in clinical anesthesia and sedation. Studies suggested that ciprofol reduced oxidative stress and inflammatory responses to alleviate cerebral ischemia/reperfusion (I/R) injury, but whether ciprofol protects the heart against I/R injury and the mechanisms are unknown. Herein, we assessed the effects of ciprofol on ferroptosis during myocardial I/R injury.

Methods

Experimental models of myocardial I/R injury in mice (ischemia for 30 min and reperfusion for 24 h) and hypoxia/reoxygenation (H/R) injury in H9c2 cardiomyocytes (hypoxia for 6 h followed by 6 h of reoxygenation) were established. Ciprofol was used prior to ischemia or hypoxia. Echocardiography, myocardial TTC staining, HE staining, DAB-enhanced Perl's staining, transmission electron microscopy, FerroOrange staining, Liperfluo staining, JC-1 staining, Rhodamine-123 staining, DCFH-DA staining, and Western blot were performed. Cell viability, serum cardiac enzymes, and oxidative- and ferroptosis-related biomarkers were measured. HIF-1α siRNA transfection and the specific inhibitor BAY87-2243 were utilized for mechanistic investigation.

Results

Ciprofol treatment reduced myocardial infarct area and myocardium damage, alleviated oxidative stress and mitochondrial injury, suppressed Fe2+ accumulation and ferroptosis, and improved cardiac function in mice with myocardial I/R injury. Ciprofol also increased cell viability, attenuated mitochondrial damage, and reduced intracellular Fe2+ and lipid peroxidation in cardiomyocytes with H/R injury. Ciprofol enhanced the protein expression of HIF-1α and GPX4 and reduced the expression of ACSL4. Specifically, the protective effects of ciprofol against I/R or H/R injury were abolished by downregulating the expression of HIF-1α using siRNA transfection or the inhibitor BAY87-2243.

Conclusion

Ciprofol ameliorated myocardial I/R injury in mice and H/R injury in cardiomyocytes by inhibiting ferroptosis via the upregulation of HIF-1α expression.

Dimethyloxalylglycine pretreatment of living donor alleviates both donor and graft liver ischemia-reperfusion injury in rats

Background: Under the circumstance of the increasing waiting list for liver transplantation, living donor liver transplantation (LDLT) can alleviate the shortage of liver donors to some extent. However, how to reduce both donor and graft ischemia-reperfusion injury (IRI) is still an unsolved problem in LDLT. Hypoxia-induced transcription factor 1 (HIF1) activation is considered an important mechanism of cellular adaptation to hypoxia, and early activation of HIF1 may be a new way to alleviate liver IRI. Therefore, we aimed to investigate the impact of the HIF1 stabilizer dimethyloxalylglycine (DMOG) on IRI and the survival rate of donors and recipients of rat LDLT. Methods: Seventy percent partial liver resection and 30% partial liver transplantation were used to simulate donor and recipient of clinical LDLT. Rats were treated with DMOG (40 mg/kg) or with an equivalent amount of saline. The expression of HIF1 and downstream targets was analyzed after 2 h of reperfusion. Liver function and histopathology, apoptosis and oxidative stress levels were detected 6 h after reperfusion. At the same time, the 7-day survival rate of rats was calculated. Results: DMOG pretreatment significantly reduced IR-induced injury in the donor and recipient, which was manifested by reducing liver function damage and promoting tissue recovery. Meanwhile, compared with the untreated group, the oxidative stress level and the cell apoptosis rate were decreased in the group pretreated with DMOG. In addition, the transcription and expression of HIF1 target genes in the DMOG group were significantly enhanced. Remarkably, DMOG also increased the survival rate of the recipient. Conclusion: This study provides the first evidence that DMOG pretreatment of donors significantly alleviates liver IRI in both donors and recipients and increases the survival rate of recipients in LDLT. Therefore, DMOG may be a promising strategy for improving LDLT in the future.