Pioglitazone Protects Against Hypoxia-Induced Cardiomyocyte Apoptosis Through Inhibiting NLRP3/Caspase-1 Pathway in vivo and in vitro

MicroRNA-specific therapeutic targets and biomarkers of apoptosis following myocardial ischemia-reperfusion injury

MicroRNAs are single-stranded non-coding RNAs that participate in post-transcriptional regulation of gene expression, it is involved in the regulation of apoptosis after myocardial ischemia-reperfusion injury. For example, the alteration of mitochondrial structure is facilitated by MicroRNA-1 through the regulation of apoptosis-related proteins, such as Bax and Bcl-2, thereby mitigating cardiomyocyte apoptosis. MicroRNA-21 not only modulates the expression of NF-κB to suppress inflammatory signals but also activates the PI3K/AKT pathway to mitigate ischemia-reperfusion injury. Overexpression of MicroRNA-133 attenuates reactive oxygen species (ROS) production and suppressed the oxidative stress response, thereby mitigating cellular apoptosis. MicroRNA-139 modulates the extrinsic death signal of Fas, while MicroRNA-145 regulates endoplasmic reticulum calcium overload, both of which exert regulatory effects on cardiomyocyte apoptosis. Therefore, the article categorizes the molecular mechanisms based on the three classical pathways and multiple signaling pathways of apoptosis. It summarizes the targets and pathways of MicroRNA therapy for ischemia-reperfusion injury and analyzes future research directions.

Pioglitazone ameliorates ischemia/reperfusion-induced acute kidney injury via oxidative stress attenuation and NLRP3 inflammasome

Acute kidney injury (AKI) induced by renal ischemia/reperfusion injury (IRI) is a severe clinical condition. ROS accumulation, antioxidant pathways deficiency, and inflammation are involved in IRI. Pioglitazone (Pio) exerts anti-inflammatory and antioxidant effects. The aim of this study was to explore the protective effects of pioglitazone against IRI-induced AKI. Pathogen-free Sprague-Dawley (SD) rats were arbitrarily divided into four groups: Sham operation group Control (CON) group, CON + Pio group, I/R + Saline group, and I/R + Pio group. In addition, HK-2 cells were subjected to hypoxia and reoxygenation to develop an H/R model for investigation of the protective mechanism of Pio. Pretreatment with pioglitazone in the model rats reduced urea nitrogen and creatinine levels, histopathological scores, and cytotoxicity after IRI. Pioglitazone treatment significantly attenuated renal cell apoptosis, decreased cytotoxicity, increased Bcl-2 expression, and downregulated Bax expression. Besides, the levels of ROS and inflammatory factors, including NLRP3, ASC, pro-IL-1β, pro-caspase-1, cleaved-caspase-1, TNF-α, IL-6, and IL-1β, in I/R rats and H/R cells were normalized by the pioglitazone treatment. Pioglitazone improved IRI-induced AKI by attenuating oxidative stress and NLRP3 inflammasome activation. Therefore, pioglitazone has the potential to serve as a novel agent for renal IRI treatment and prevention.

Paeoniflorin attenuates cuproptosis and ameliorates left ventricular remodeling after AMI in hypobaric hypoxia environments

This study investigates the cardioprotective effects of Paeoniflorin (PF) on left ventricular remodeling following acute myocardial infarction (AMI) under conditions of hypobaric hypoxia. Left ventricular remodeling post-AMI plays a pivotal role in exacerbating heart failure, especially at high altitudes. Using a rat model of AMI, the study aimed to evaluate the cardioprotective potential of PF under hypobaric hypoxia. Ninety male rats were divided into four groups: sham-operated controls under normoxia/hypobaria, an AMI model group, and a PF treatment group. PF was administered for 4 weeks after AMI induction. Left ventricular function was assessed using cardiac magnetic resonance imaging. Biochemical assays of cuproptosis, oxidative stress, apoptosis, inflammation, and fibrosis were performed. Results demonstrated PF significantly improved left ventricular function and remodeling after AMI under hypobaric hypoxia. Mechanistically, PF decreased FDX1/DLAT expression and serum copper while increasing pyruvate. It also attenuated apoptosis, inflammation, and fibrosis by modulating Bcl-2, Bax, NLRP3, and oxidative stress markers. Thus, PF exhibits therapeutic potential for left ventricular remodeling post-AMI at high altitude by inhibiting cuproptosis, inflammation, apoptosis and fibrosis. Further studies are warranted to optimize dosage and duration and elucidate PF's mechanisms of action.

Modified Linggui Zhugan Decoction protects against ventricular remodeling through ameliorating mitochondrial damage in post-myocardial infarction rats

Introduction

Modified Linggui Zhugan Decoction (MLZD) is a Traditional Chinese Medicine prescription developed from Linggui Zhugan Decoction (LZD) that has been used for the clinical treatment of ischemic cardiovascular diseases. However, the cardioprotective mechanism of MLZD against post-myocardial infarction (MI) ventricular remodeling remains unclear.

Methods

We explored the effects of MLZD on ventricular remodeling and their underlying mechanisms, respectively, in SD rats with MI models and in H9c2 cardiomyocytes with oxygen-glucose deprivation (OGD) models. The cardiac structure and function of rats were measured by echocardiography, HE staining, and Masson staining. Apoptosis, inflammation, mitochondrial structure and function, and sirtuin 3 (SIRT3) expression were additionally examined.

Results

MLZD treatment significantly ameliorated cardiac structure and function, and thus reversed ventricular remodeling, compared with the control. Further research showed that MLZD ameliorated mitochondrial structural disruption, protected against mitochondrial dynamics disorder, restored impaired mitochondrial function, inhibited inflammation, and thus inhibited apoptosis. Moreover, the decreased expression level of SIRT3 was enhanced after MLZD treatment. The protective effects of MLZD on SIRT3 and mitochondria, nevertheless, were blocked by 3-TYP, a selective inhibitor of SIRT3.

Discussion

These findings together revealed that MLZD could improve the ventricular remodeling of MI rats by ameliorating mitochondrial damage and its associated apoptosis, which might exert protective effects by targeting SIRT3.