Modified Protocol for A Mouse Heart Failure Model Using Minimally Invasive Transverse Aortic Constriction

Huangqi-Danshen decoction improves heart failure by regulating pericardial adipose tissue derived extracellular vesicular miR-27a-3p to activate AMPKα2 mediated mitophagy

BACKGROUND

Huangqi-Danshen decoction (HDD) is a classic traditional Chinese medicine for treating heart failure. Pericardial adipose tissue (PAT) has recently gained increasing attention in cardiovascular diseases.

PURPOSE

This study aimed to investigate the effect of pericardial adipose tissue-derived extracellular vesicles on heart failure, the protective effect of HDD on myocardial remodel in heart failure rats, and identify the potential molecular mechanisms involved.

METHODS

UPLC-MS/MS identified active components of HDD. Extracellular vesicles (EVs) from pericardial adipose tissue of sham-operated and HF rats were identified through transmission electron microscopy, nanoparticle tracking analysis and western blot. EVs were co-cultured with H9c2 cardiomyocytes in order to examine their uptake and effects. MicroRNA sequencing, dual-luciferase reporter assay and PCR were conducted for exploring specific mechanisms of EVs on hypertrophic cardiomyocytes. In vivo, heart failure was modeled in rats via transverse aortic constriction (TAC). In vitro, the hypertrophic cardiomyocyte model were established using Ang II-induced H9c2 cardiomyocytes.

RESULTS

UPLC-MS/MS identified 11 active components in serum of HDD administrated rats. Echocardiography showed HDD improved cardiac function in TAC model rats. HE and Masson staining indicated HDD ameliorated myocardial hypertrophy and fibrosis. MicroRNA sequencing found that HDD treatment resulted in 37 differentially expressed miRNAs (DMEs) (p < 0.05 and |log2FC| ≥ 1). KEGG analysis revealed that DEMs were enriched in the AMPK signaling pathway. PCR identified miR-27a-3p with the greatest difference in AMPK-related DMEs. Dual-luciferase reporter assay and Targetscan website were utilized to identify the target relationship between miR-27a-3p and PRKAA2 (AMPKα2). The miR-27a-3p negatively regulated AMPKα2 to inhibit mitophagy mediated by PINK1/Parkin pathway. HDD inhibited miR-27a-3p secretion from failing heart pericardial adipose tissue-derived extracellular vesicles, thereby improving inflammation, cardiac function, and myocardial remodeling through above pathways.

CONCLUSION

HDD inhibited the PAT-derived extracellular vesicular miR-27a-3p in failing hearts to activate AMPK/PINK1/Parkin signaling-mediated mitophagy, which improved cardiomyocyte energy metabolism, myocardial remodeling and heart failure.

Cardiomyocyte-derived USP28 negatively regulates antioxidant response and promotes cardiac hypertrophy via deubiquitinating TRIM21

Rationale: Cardiac hypertrophy is an important pathological basis for heart failure. Most physiological activities of cardiomyocytes are regulated by proteins and their post-translational modification. Deubiquitinating enzymes (DUBs) are involved in protein stability maintenance and closely related to myocardial hypertrophy. In this study, we aimed to clarify the regulatory role of a DUB, ubiquitin-specific peptidase 28 (USP28), in cardiac hypertrophy and explore the molecular mechanism behind. Methods: Transcriptome and single-cell mRNA sequencing was used to demonstrate the association of USP28 and cardiac hypertrophy. Cardiomyocyte-specific USP28 knockout mice (USP28CKO) were subjected to angiotensin II (Ang II) infusion or transverse aortic constriction (TAC) models. Coimmunoprecipitation combined mass spectrum analysis (Co-IP/MS) was applied to screen out the substrate of USP28. Results: We first showed the up-regulation of USP28 in cardiac hypertrophy, and its cellular localization of cardiomyocytes. USP28CKO protects mouse heart against Ang II- or TAC-induced cardiac dysfunction and hypertrophy. Mechanistically, we identified tripartite motif-containing protein 21 (TRIM21) as the potential substrate of USP28 by Co-IP/MS analysis. Cardiomyocyte USP28 deubiquitinates and stabilizes TRIM21 to negatively regulate nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant response, increasing oxidative stress in cardiomyocytes and promoting cardiac hypertrophy and injury. Finally, using a selective USP28 inhibitor Otilonium Bromide, we confirmed the therapeutic effect of pharmacological inhibition of USP28 against TAC-induced established hypertrophic heart failure. Conclusion: Our study illustrates a cardiomyocyte-specific USP28-TRIM21 axis in regulating hypertrophic cardiomyopathy and presents USP28 as a potential target for the treatment of cardiac hypertrophy.

A time-series minimally invasive transverse aortic constriction mouse model for pressure overload-induced cardiac remodeling and heart failure

Transverse aortic constriction (TAC) is a widely-used animal model for pressure overload-induced cardiac hypertrophy and heart failure (HF). The severity of TAC-induced adverse cardiac remodeling is correlated to the degree and duration of aorta constriction. Most studies of TAC are performed with a 27-gauge needle, which is easy to cause a tremendous left ventricular overload and leads to a rapid HF, but it is accompanied by higher mortality attributed to tighter aortic arch constriction. However, a few studies are focusing on the phenotypes of TAC applied with a 25-gauge needle, which produces a mild overload to induce cardiac remodeling and has low post-operation mortality. Furthermore, the specific timeline of HF induced by TAC applied with a 25-gauge needle in C57BL/6 J mice remains unclear. In this study, C57BL/6 J mice were randomly subjected to TAC with a 25-gauge needle or sham surgery. Echocardiography, gross morphology, and histopathology were applied to evaluate time-series phenotypes in the heart after 2, 4, 6, 8, and 12 weeks. The survival rate of mice after TAC was more than 98%. All mice subjected to TAC maintained compensated cardiac remodeling during the first two weeks and began to exhibit heart failure characteristics after 4 weeks upon TAC. At 8 weeks post-TAC, the mice showed severe cardiac dysfunction, hypertrophy, and cardiac fibrosis compared to sham mice. Moreover, the mice raised a severe dilated HF at 12 weeks. This study provides an optimized method of the mild overload TAC-induced cardiac remodeling from the compensatory period to decompensatory HF in C57BL/6 J mice.

Large and Small Animal Models of Heart Failure With Reduced Ejection Fraction

Heart failure (HF) describes a heterogenous complex spectrum of pathological conditions that results in structural and functional remodeling leading to subsequent impairment of cardiac function, including either systolic dysfunction, diastolic dysfunction, or both. Several factors chronically lead to HF, including cardiac volume and pressure overload that may result from hypertension, valvular lesions, acute, or chronic ischemic injuries. Major forms of HF include hypertrophic, dilated, and restrictive cardiomyopathy. The severity of cardiomyopathy can be impacted by other comorbidities such as diabetes or obesity and external stress factors. Age is another major contributor, and the number of patients with HF is rising worldwide in part due to an increase in the aged population. HF can occur with reduced ejection fraction (HF with reduced ejection fraction), that is, the overall cardiac function is compromised, and typically the left ventricular ejection fraction is lower than 40%. In some cases of HF, the ejection fraction is preserved (HF with preserved ejection fraction). Animal models play a critical role in facilitating the understanding of molecular mechanisms of how hearts fail. This review aims to summarize and describe the strengths, limitations, and outcomes of both small and large animal models of HF with reduced ejection fraction that are currently used in basic and translational research. The driving defect is a failure of the heart to adequately supply the tissues with blood due to impaired filling or pumping. An accurate model of HF with reduced ejection fraction would encompass the symptoms (fatigue, dyspnea, exercise intolerance, and edema) along with the pathology (collagen fibrosis, ventricular hypertrophy) and ultimately exhibit a decrease in cardiac output. Although countless experimental studies have been published, no model completely recapitulates the full human disease. Therefore, it is critical to evaluate the strength and weakness of each animal model to allow better selection of what animal models to use to address the scientific question proposed.