Aminoacylase-1 plays a key role in myocardial fibrosis and the therapeutic effects of 20(S)-ginsenoside Rg3 in mouse heart failure.

We previously found that the levels of metabolite N-acetylglutamine were significantly increased in urine samples of patients with heart failure (HF) and in coronary artery ligation (CAL)-induced HF mice, whereas the expression of its specific metabolic-degrading enzyme aminoacylase-1 (ACY1) was markedly decreased. In the current study, we investigated the role of ACY1 in the pathogenesis of HF and the therapeutic effects of 20(S)-ginsenoside Rg3 in HF experimental models in vivo and in vitro. HF was induced in mice by CAL. The mice were administered Rg3 (7.5, 15, 30 mg · kg-1· d-1, i.g.), or positive drug metoprolol (Met, 5.14 mg · kg-1· d-1, i.g.), or ACY1 inhibitor mono-tert-butyl malonate (MTBM, 5 mg · kg-1 · d-1, i.p.) for 14 days. We showed that administration of MTBM significantly exacerbated CAL-induced myocardial injury, aggravated cardiac dysfunction, and pathological damages, and promoted myocardial fibrosis in CAL mice. In Ang II-induced mouse cardiac fibroblasts (MCFs) model, overexpression of ACY1 suppressed the expression of COL3A1 and COL1A via inhibiting TGF-ß1/Smad3 pathway, whereas ACY1-siRNA promoted the cardiac fibrosis responses. We showed that a high dose of Rg3 (30 mg · kg-1· d-1) significantly decreased the content of N-acetylglutamine, increased the expression of ACY1, and inhibited TGF-ß1/Smad3 pathway in CAL mice; Rg3 (25 µM) exerted similar effects in Ang II-treated MCFs. Meanwhile, Rg3 treatment ameliorated cardiac function and pathological features, and it also attenuated myocardial fibrosis in vivo and in vitro. In Ang II-treated MCFs, the effects of Rg3 on collagen deposition and TGF-ß1/Smad3 pathway were slightly enhanced by overexpression of ACY1, whereas ACY1 siRNA partially weakened the beneficial effects of Rg3, suggesting that Rg3 might suppress myocardial fibrosis through ACY1. Our study demonstrates that N-acetylglutamine may be a potential biomarker of HF and its specific metabolic-degrading enzyme ACY1 could be a potential therapeutic target for the prevention and treatment of myocardial fibrosis during the development of HF. Rg3 attenuates myocardial fibrosis to ameliorate HF through increasing ACY1 expression and inhibiting TGF-ß1/Smad3 pathway, which provides some references for further development of anti-fibrotic drugs for HF.

HPLC-QTOF/MS-based metabolomics to explore the molecular mechanisms of Yiqi Fumai Lyophilized Injection in heart failure mice.

Chronic heart failure is a common and fatal disease triggered by loss of normal cardiac function. Yiqi Fumai Lyophilized Injection is widely used in the treatment of cardiovascular diseases, especially chronic heart failure. In this study, a model of chronic heart failure in mice was established with permanent coronary artery ligation followed by Yiqi Fumai Lyophilized Injection intervention for 14 days. Then, the endogenous metabolites of mice plasma and urine samples were screened through nontargeted metabolomics techniques. The results indicated that Yiqi Fumai Lyophilized Injection treatment changed the metabolic pattern of chronic heart failure and regulated valine, leucine, and isoleucine biosynthesis, taurine and hypotaurine metabolism, histidine metabolism and arginine biosynthesis, etc. Finally, the cardioprotective mechanism of Yiqi Fumai Lyophilized Injection was further verified in the mouse model of chronic heart failure and angiotensin II-induced cardiac fibroblasts based on metabolomics. The results showed that Yiqi Fumai Lyophilized Injection could inhibit myocardial fibrosis to improve chronic heart failure. This study firstly elucidated the metabolic network and pathways regulated by Yiqi Fumai Lyophilized Injection, which might facilitate the realization of the clinically accurate application of Yiqi Fumai Lyophilized Injection in the treatment of chronic heart failure.

Exploring the protective effects of schizandrol A in acute myocardial ischemia mice by comprehensive metabolomics profiling integrated with molecular mechanism studies.

Schizandrol A (SA) is an bioactive component isolated from the Schisandra chinensis (Turcz.) Baill., which has been used as a remedy to prevent oxidative injury. However, whether the cardioprotective effect of SA is associated with regulating endogenous metabolites remains unclear, thus we performed comprehensive metabolomics profiling in acute myocardial ischemia (AMI) mice following SA treatment. AMI was induced in ICR mice by coronary artery ligation, then SA (6 mg·kg-1·d-1, ip) was administered. SA treatment significantly decreased the infarct size, preserved the cardiac function, and improved the biochemical indicators and cardiac pathological alterations. Moreover, SA (10, 100 M) significantly decreased the apoptotic index in OGD-treated H8c2 cardiomycytes in vitro. By using HPLC-Q-TOF/MS, we conducted metabonomics analysis to screen the significantly changed endogenous metabolites and construct the network in both serum and urine. The results revealed that SA regulated the pathways of glycine, serine and threonine metabolism, lysine biosynthesis, pyrimidine metabolism, arginine and proline metabolism, cysteine and methionine metabolism, valine, leucine and isoleucine biosynthesis under the pathological conditions of AMI. Furthermore, we selected the regulatory enzymes related to heart disease, including ecto-5'-nucleotidase (NT5E), guanidinoacetate N-methyltransferase (GAMT), platelet-derived endothelial cell growth factor (PD-ECGF) and methionine synthase (MTR), for validation. In addition, SA was found to facilitate PI3K/Akt activation and inhibit the expression of NOX2 in AMI mice and OGD-treated H9c2 cells. In conclusion, we have elucidated SA-regulated endogenous metabolic pathways and constructed a regulatory metabolic network map. Furthermore, we have validated the new potential therapeutic targets and underlying molecular mechanisms of SA against AMI, which might provide a reference for its future application in cardiovascular diseases.

Study on the association between drug­resistance and gene mutations of the active efflux pump acrAB­tolC gene and its regulatory genes.

The aim of the present study was to investigate the correlation between the multi­drug resistance of Shigella flexneri and the drug­resistant gene cassette carried by integrons; in the meanwhile, to detect the associations between drug­resistance and gene mutations of the active efflux pump acrAB­tolC gene and its regulatory genes, including marOR, acrR and soxS. A total of 158 isolates were isolated from the stool samples of 1,026 children with diarrhoea aged 14 years old between May 2012 and October 2015 in Henan. The K­B method was applied for the determination of drug resistance of Shigella flexneri, and polymerase chain reaction amplification was used for class 1, 2 and 3 integrase genes. Enzyme digestion and sequence analysis were performed for the variable regions of positive strains. Based on the drug sensitivity assessment, multi­drug resistant strains that were resistant to five or more antibiotics, and sensitive strains were selected for amplification. Their active efflux pump genes, acrA and acrB, and regulatory genes, marOR, acrR and soxS, were selected for sequencing. The results revealed that 91.1% of the 158 strains were multi­resistant to ampicillin, chloramphenicol, tetracycline and streptomycin, and 69.6% of the strains were multi­resistant to sulfamethoxazole/trimethoprim. The resistance to ceftazidime, ciprofloxacin and levofloxacin was <32.9%. All strains (100%) were sensitive to cefoxitin, cefoperazone/sulbactam and imipenem. The rate of the class 1 integron positivity was 91.9% (144/158). Among these class 1 integron­positive strains, 18 strains exhibited the resistance gene cassette dfrV in the variable region of the strain, four strains exhibited dfrA17­aadA5 in the variable region and 140 strains exhibited blaOXA­30­aadA1 in the variable region. Four strains showed no resistance gene in the variable regions. The rate of class 2 integron positivity was 86.1% (136/158), and all positive strains harboured the dfrA1­sat1­aadA resistance gene cassette in the variable region. The class 3 integrase gene was not detected in these strains. The gene sequencing showed the deletion of base CATT in the 36, 37, 38, 39 site in the marOR gene, which is a regulatory gene of the active efflux pump, AcrAB­TolC. Taken together, the multi­drug resistance of Shigella flexneri was closely associated with gene mutations of class 1 and 2 integrons and the marOR gene.