A four-compound remedy AGILe protected H9c2 cardiomyocytes against oxygen glucose deprivation via targeting the TNF-α/NF-κB pathway: Implications for the therapy of myocardial infarction

MicroRNA-322-5p targeting Smurf2 regulates the TGF-β/Smad pathway to protect cardiac function and inhibit myocardial infarction

Acute coronary artery blockage leads to acute myocardial infarction (AMI). Cardiomyocytes are terminally differentiated cells that rarely divide. Treatments preventing cardiomyocyte loss during AMI have a high therapeutic benefit. Accumulating evidence shows that microRNAs (miRNAs) may play an essential role in cardiovascular diseases. This study aims to explore the biological function and underlying regulatory molecular mechanism of miR-322-5p on myocardial infarction (MI). This study's miR-322-5p is downregulated in MI-injured hearts according to integrative bioinformatics and experimental analyses. In the MI rat model, miR-322-5p overexpression partially eliminated MI-induced changes in myocardial enzymes and oxidative stress markers, improved MI-caused impairment on cardiac functions, inhibited myocardial apoptosis, attenuated MI-caused alterations in TGF-β, p-Smad2, p-Smad4, and Smad7 protein levels. In oxygen-glucose deprivation (OGD)-injured H9c2 cells, miR-322-5p overexpression partially rescued OGD-inhibited cell viability and attenuated OGD-caused alterations in the TGF-β/Smad signaling. miR-322-5p directly targeted Smurf2 and inhibited Smurf2 expression. In OGD-injured H9c2 cells, Smurf2 knockdown exerted similar effects to miR-322-5p overexpression upon cell viability and TGF-β/Smad signaling; moreover, Smurf2 knockdown partially attenuated miR-322-5p inhibition effects on OGD-injured H9c2 cells. In conclusion, miR-322-5p is downregulated in MI rat heart and OGD-stimulated rat cardiomyocytes; the miR-322-5p/Smurf2 axis improves OGD-inhibited cardiomyocyte cell viability and MI-induced cardiac injuries and dysfunction through the TGF-β/Smad signaling.

Omaveloxolone ameliorates isoproterenol-induced pathological cardiac hypertrophy in mice

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important transcriptional regulator that plays a protective role against various cardiovascular diseases. Omaveloxolone is a newly discovered potent activator of Nrf2 that has a variety of cytoprotective functions. However, the potential role of omaveloxolone in the process of pathological cardiac hypertrophy and heart failure are still unknown. In this study, an isoproterenol (ISO)-induced pathological cardiac hypertrophy model was established to investigate the protective effect of omaveloxolone in vivo and in vitro. Our study first confirmed that omaveloxolone administration improved ISO-induced pathological cardiac hypertrophy in mice and neonatal cardiomyocytes. Omaveloxolone administration also diminished ISO-induced cardiac oxidative stress, inflammation and cardiomyocyte apoptosis. In addition, omaveloxolone administration activated the Nrf2 signaling pathway, and Nrf2 knockdown almost completely abolished the cardioprotective effect of omaveloxolone, indicated that the cardioprotective effect of omaveloxolone was directly related to the activation of the Nrf2 signaling. In summary, our study identified that omaveloxolone may be a promising therapeutic agent to mitigate pathological cardiac hypertrophy.

Pharmacokinetic evaluation of 24 representative components of Ling-Gui-Zhu-Gan decoction in acute myocardial infarction model rats via a validated ultrahigh-performance liquid chromatography-tandem mass spectrometry method

RATIONALE

Ling-Gui-Zhu-Gan decoction (LGZGD), one of the 100 herbal classic formulas, is clinically used to treat chronic heart failure with remarkable curative effect. However, LGZGD pharmacokinetic parameters in pathological model rats are poorly understood, in particular for special components. As physicochemical properties are specific to each representative component, no standard sample preparation is available for absolute quantification of representative components of LGZGD in rat plasma.

METHODS

A specific, sensitive and high-throughput ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS) method capturing 24 representative components was developed and applied to evaluate the pharmacokinetic parameters of LGZGD in acute myocardial infarction (AMI) rat plasma after intragastric administration (2.4, 4.8 and 9.6 g/kg). Precipitation and extraction were selected and optimized for plasma preparation, and isopropanol precipitation could offer higher recovery and broader coverage.

RESULTS

It was expected that AMI could cause less absorption and slower elimination of most of active components of LGZGD. Most of newly reported special components absorbed quickly and eliminated slowly. The average elimination half-life of the 24 representative components was 10.09 h, which is consistent with the dosage of LGZGD (twice daily).

CONCLUSIONS

The specificity, linearity, precision and accuracy, recovery, matrix effect and stability were validated according to Food and Drug Administration guidance. The validation results demonstrated that the method could be applied to evaluate the pharmacokinetic parameters of LGZGD in AMI rats. The pharmacokinetic parameters showed substantial improvement in quality research of LGZGD, thereby laying the groundwork for preclinical and clinical trials in chronic heart failure clinical efficacy.