Fraxinellone ameliorates intracerebral hemorrhage-induced secondary brain injury by regulating Krüppel-like transcription factor 2 expression in rats

Fraxinellone protects against cardiac injury and decreases ventricular fibrillation susceptibility during myocardial ischemia-reperfusion

BACKGROUND

Acute myocardial ischemia/reperfusion injury (MIRI) with complicated mechanisms contributes to a high risk of ventricular arrhythmia, high lethality, and even sudden death. In vitro, Fraxinellone (FRA) exhibits an array of biologic activities and may possess cardioprotective effects. However, no relevant studies have examined FRA's protective potential against MIRI and related ventricular arrhythmias. The present study was undertaken to determine the effectiveness of FRA on MIRI and ventricular fibrillation (VF) susceptibility in rats and to elucidate the underlying mechanisms.

METHODS

48 healthy male Sprague-Dawley (SD) rats were randomly divided into the following four groups: Sham+vehicle(n=12), Sham+FRA(n=12), I/R+vehicle(n=12) and I/R+FRA(n=12). Histopathology, electrophysiological examination, HRV analysis in combination with molecular biology were used to investigate the therapeutic benefits of FRA on cardiac injury and VF susceptibility during myocardial IR. Finally, the potential mechanism by which FRA protects myocardium from MIRI was explored.

RESULTS

Pretreatment with FRA ameliorated myocardial fibrosis after MIRI in vivo, alleviated myocardial injury, inflammation, oxidative stress and apoptosis in vivo and in vitro, thereby protecting myocardium from MIRI injury. In addition, FRA administration could improve HRV, prolong ventricular effective refractory period (ERP) and action potential duration (APD), attenuate VF induction rate, and contribute to improving ventricular sympathetic nerve remodeling and ion channel remodeling. Mechanistically, FRA may reduce MIRI via the PI3K/AKT pathway.

CONCLUSION

FRA may exert cardioprotective effects during MIRI by inhibiting myocardial inflammation, oxidative stress and apoptosis, and decrease VF susceptibility by improving sympathetic remodeling and ion channel remodeling, which might represent a potential therapeutic strategy for attenuation of MIRI.

Exploring the correlation between innate immune activation of inflammasome and regulation of pyroptosis after intracerebral hemorrhage: From mechanism to treatment

Stroke has emerged as the primary cause of disability and death globally in recent years. Intracerebral hemorrhage (ICH), a particularly severe kind of stroke, is occurring in an increasing number of people. The two main clinical treatments for ICH now in use are conservative pharmaceutical therapy and surgical intervention, both of which have risks and drawbacks. Consequently, it is crucial to look into the pathophysiology of ICH and consider cutting-edge therapeutic approaches. Recent research has revealed that pyroptosis is a newly identified type of cell death distinguished by the break of the cell membrane and the discharge of pro-inflammatory substances through different routes. Following ICH, glial cells experience pyroptosis, which worsens neuroinflammation. Hence, the onset and progression of ICH are strongly linked to pyroptosis, which is facilitated by different inflammasomes. It is essential to conduct a comprehensive investigation of ICH damage processes and uncover new targets for treatment. The impact and function of pyroptosis in ICH, as well as the activation and regulation of inflammasomes and their mediated pyroptosis pathways will be fully discussed in this review.

The Mechanism of Astragaloside IV in NOD-like Receptor Family Pyrin Domain Containing 3 Inflammasome-mediated Pyroptosis after Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is one of the most common subtypes of stroke.

OBJECTIVES

This study aimed to investigate the mechanism of Astragaloside IV (AS-IV) on inflammatory injury after ICH.

METHODS

The ICH model was established by the injection of collagenase and treated with ASIV (20 mg/kg or 40 mg/kg). The neurological function, water content of the bilateral cerebral hemisphere and cerebellum, and pathological changes in brain tissue were assessed. The levels of interleukin-1 beta (IL-1β), IL-18, tumor necrosis factor-alpha, interferon-gamma, and IL-10 were detected by enzyme-linked immunosorbent assay. The levels of Kruppel-like factor 2 (KLF2), NOD-like receptor family pyrin domain containing 3 (NLRP3), GSDMD-N, and cleaved-caspase-1 were detected by reverse transcription-quantitative polymerase chain reaction and Western blot assay. The binding relationship between KLF2 and NLRP3 was verified by chromatin-immunoprecipitation and dual-luciferase assays. KLF2 inhibition or NLRP3 overexpression was achieved in mice to observe pathological changes.

RESULTS

The decreased neurological function, increased water content, severe pathological damage, and inflammatory response were observed in mice after ICH, with increased levels of NLRP3/GSDMD-N/cleaved-caspase-1/IL-1β/IL-18 and poorly-expressed KLF2 in brain tissue. After AS-IV treatment, the neurological dysfunction, high brain water content, inflammatory response, and pyroptosis were alleviated, while KLF2 expression was increased. KLF2 bonded to the NLRP3 promoter region and inhibited its transcription. Down-regulation of KLF2 or upregulation of NLRP3 reversed the effect of AS-IV on inhibiting pyroptosis and reducing inflammatory injury in mice after ICH.

CONCLUSION

AS-IV inhibited NLRP3-mediated pyroptosis by promoting KLF2 expression and alleviated inflammatory injury in mice after ICH.