Vaspin Alleviates Sepsis-Induced Cardiac Injury and Cardiac Inflammation by Inhibiting Kallikrein 7 in Mice.

Background: Vaspin is an important adipokine that is involved in cardiovascular diseases. This study is aimed at investigating whether vaspin participates in sepsis-induced cardiac injury and explored the possible mechanism. Methods: First, cecal ligation and puncture (CLP) and lipopolysaccharide (LPS) were used to establish a mouse model of sepsis, and cardiac vaspin expression was examined. In addition, after pretreatment with vaspin or phosphate-buffered saline (PBS), wild-type (WT) mice underwent CLP to establish a septic model and received sham as a control. Finally, WT mice and kallikrein 7 (KLK7-/-) mice were underwent CLP with or without vaspin pretreatment. Results: Mice that underwent CLP and were administered LPS exhibited increased vaspin expression in both the heart and serum compared with sham- or saline-treated mice. In CLP mice, pretreatment with vaspin reduced mortality and alleviated the expression of cardiac injury markers and cardiac dysfunction. In addition, vaspin reduced the cardiac levels of CD45+ cells and CD68+ cells, alleviated the cardiac inflammatory response, and reduced cardiomyocyte apoptosis. The protective effects of vaspin on CLP mice were masked by the deletion of KLK7, which was demonstrated to be a downstream signal of vaspin. Conclusions: Vaspin alleviates cardiac inflammation and plays a protective role in sepsis-induced cardiac injury by reducing KLK7 expression.

A novel function of ATF3 in suppression of ferroptosis in mouse heart suffered ischemia/reperfusion.

INTRODUCTION: Ferroptosis, a newly identified type of programmed cell death type, has been proven to contribute to the progression of myocardial ischemia/reperfusion (I/R) injury. However, little is known about ferroptosis regulation in I/R injury. OBJECTIVES: We identified activating transcription factor 3 (ATF3) as a vital regulator of I/R induced ferroptosis and investigated the effects and potential mechanism of ATF3 in cardiac ferroptosis. METHODS: In this study, the dynamic RNA-sequencing (RNA-seq) analysis were performed on mouse hearts exposed to different I/R schedules to identify that ATF3 represents an important modulatory molecule in myocardial I/R injury. Then knockout, rescue and overexpression methods were used in mice and neonatal mouse cells (NMCs) to illustrate the effect of ATF3 on myocardial I/R injury. Loss/gain of function techniques were used both in vivo and in vitro to explore the effects of ATF3 on ferroptosis in I/R injury. Furthermore, chromatin immunoprecipitation sequence (ChIP-seq) analysis was performed in the AC16 human cardiomyocyte cell line to investigate potential genes regulated by ATF3. RESULTS: ATF3 expression reached highest level at early stage of reperfusion, knockout of ATF3 significantly aggravated I/R injury, which could be rescued by ATF3 re-expression. Knockout and the re-expression of ATF3 changed the transcription levels of multiple ferroptosis genes. In addition, results showed that overexpression of ATF3 inhibits cardiomyocyte ferroptosis triggered by erastin and RSL3. Lastly, ChIP-seq and dual luciferase activity analysis revealed ATF3 could bind to the transcription start site of Fanconi anaemia complementation group D2 (FANCD2) and increased the FANCD2 promoter activity. Furthermore, we first demonstrated that overexpression of FANCD2 exerts significant anti-ferroptosis and cardioprotective effect on AC16 cell H/R injury. CONCLUSION: ATF3 inhibits cardiomyocyte ferroptotic death in I/R injury, which might be related with regulating FANCD2. Our study provides new insight into the molecular target for the therapy of myocardial I/R injury.

Viscosity-projection method for a family of general equilibrium problems and asymptotically strict pseudocontractions in the intermediate sense.

In this paper, a Meir-Keeler contraction is introduced to propose a viscosity-projection approximation method for finding a common element of the set of solutions of a family of general equilibrium problems and the set of fixed points of asymptotically strict pseudocontractions in the intermediate sense. Strong convergence of the viscosity iterative sequences is obtained under some suitable conditions. Results presented in this paper extend and unify the previously known results announced by many other authors.