Imidapril and Enalapril Similarly Inhibit Plasma Matrix Metalloproteinase Activities and Attenuate Left Ventricular Remodeling in Patients With Acute Myocardial Infarction:

Non-invasive tragus stimulation improves cardiac post-ischemic remodeling by regulating cardiac parasympathetic activity

AIMS

Our previous study proved that low-level tragus nerve stimulation (LL-TS) could improve left ventricular remodelling by cardiac down-stream mechanisms. However, the cardiac up-stream mechanisms remain unknown.

METHODS AND RESULTS

Twenty-eight adult beagle dogs were randomly divided into an MI group (myocardial infarction was induced by permanent ligation of the left coronary artery, n = 10), an LL-TS group (MI plus intermittent LL-TS treatment, n = 10), and a control group (sham ligation with the same stimulation as the LL-TS group, n = 8). Auricular tragus nerve was bilaterally delivered to the tragus via ear-clips connected to a custom-made stimulator. The voltage slowing sinus rate was used as the threshold to set the LL-TS 80% below this level. At the end of 4 weeks post-MI, LL-TS could significantly increase atrial ganglion plex (GP) activity, decreased left stellate ganglion (LSG) activity, reduced LV dilation, and improved ventricular functions. Chronic intermittent LL-TS treatment significantly attenuated left ventricular remodelling via the up-regulation of α7nAChR expression and the down-regulation of MMP-9 level in post-MI LV tissue. The elevated protein and mRNA of MMP-9 levels in remote areas were significantly ameliorated by LL-TS treatment.

CONCLUSIONS

Chronic LL-TS increased GP neural activity and improved ventricular remodelling possibly via α7nAChR/MMP-9 axis.

Access to Cyclic N-Trifluoromethyl Ureas through Photocatalytic Activation of Carbamoyl Azides

We report the mild activation of carbamoyl azides to the corresponding nitrenes using a blue light/[Ir]-catalyzed strategy, which enables stereospecific access to N-trifluoromethyl imidazolidinones and benzimidazolones. These novel structural motifs proved to be highly robust, allowing their downstream diversification. On the basis of our combined computational and experimental studies, we propose that an electron rebound with the excited metal catalyst is undergone, involving a reduction-triggered nitrogen loss, followed by oxidation to the corresponding carbamoyl nitrene and subsequent C-H insertion.

Traditional Chinese Medicine Intervenes Ventricular Remodeling Following Acute Myocardial Infarction: Evidence From 40 Random Controlled Trials With 3,659 Subjects

Objectives: We intend to conduct a meta-analysis on the systematic evaluation of traditional Chinese medicine (TCM) in the treatment of ventricular remodeling following acute myocardial infarction (AMI). Our findings may provide certain references for the clinical treatment of ventricular remodeling.

Methods: A systematic literature search was conducted in PubMed, Web of Science, Cochrane Library, Embase, CNKI, Wanfang Data, CQVIP, and CBM before 20 July 2020. Data were analyzed using a random/fixed-effect model. Primary outcomes included the effectiveness and TCM syndrome score (TCMSS). Secondary outcomes included 1) echocardiography data, including the left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic volume index (LVEDVi), left ventricular end-systolic volume index (LVESVi), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular ejection fraction (LVEF), E/A, stroke volume (SV), and wall motion score (WMS); 2) serum indicators, including the B-type natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NT-proBNP), and C-reactive protein (CRP) or high sensitivity CRP (hs-CRP); (3) major adverse cardiovascular events (MACE) and other adverse events

Results: Forty RCTs involving 3,659 subjects were recruited. Our findings proved that a combination of TCM or TCM preparations with conventional Western medicine for preventing and reversing ventricular remodeling at post-AMI could remarkably enhance the total effectiveness and reduced TCMSS. Moreover, myocardial functions (LVEF, E/A, and SV), ventricular remodeling (LVEDVi, LVESVi, LVEDV, LVESV, LVEDD, LVESD, LVPWT, and WMS), serum levels of BNP and CRP, and MACE were significantly improved by the combination of TCM or TCM preparations with conventional Western medicine. Nevertheless, IVST and the incidence of other adverse events were comparable between control and experimental groups

Conclusion: The combination of TCM or TCM preparations and conventional Western medicine can alleviate the process of ventricular remodeling, enhance cardiac function, and reduce the incidence of MACE in AMI patients.

Hexarelin targets neuroinflammatory pathways to preserve cardiac morphology and function in a mouse model of myocardial ischemia-reperfusion

Acute myocardial ischemia and reperfusion injury (IRI) underly the detrimental effects of coronary heart disease on the myocardium. Despite the ongoing advances in reperfusion therapies, there remains a lack of effective therapeutic strategies for preventing IRI. Growth hormone secretagogues (GHS) have been demonstrated to improve cardiac function, attenuate inflammation and modulate the autonomic nervous system (ANS) in models of cardiovascular disease. Recently, we demonstrated a reduction in infarct size after administration of hexarelin (HEX), in a murine model of myocardial infarction. In the present study we employed a reperfused ischemic (IR) model, to determine whether HEX would continue to have a cardioprotective influence in a model of higher clinical relevance. Myocardial ischemia was induced by transient ligation of the left descending coronary artery (tLAD) in C57BL/6 J mice followed by HEX (0.3 mg/kg/day; n = 20) or vehicle (VEH) (n = 18) administration for 21 days, first administered immediately prior-to reperfusion. IR-injured and sham mice were subjected to high-field magnetic resonance imaging to assess left ventricular (LV) function, with HEX-treated mice demonstrating a significant improvement in LV function compared with VEH-treated mice. A significant decrease in interstitial collagen, TGF-β1 expression and myofibroblast differentiation was also seen in the HEX-treated mice after 21 days. HEX treatment shifted the ANS balance towards a parasympathetic predominance; combined with a significant decrease in cardiac troponin-I and TNF-α levels, these findings were suggestive of an anti-inflammatory action on the myocardium mediated via HEX. In this model of IR, HEX appeared to rebalance the deregulated ANS and activate vagal anti-inflammatory pathways to prevent adverse remodelling and LV dysfunction. There are limited interventions focusing on IRI that have been successful in improving clinical outcome in acute myocardial infarction (AMI) patients, this study provides compelling evidence towards the translational potential of HEX where all others have largely failed.

Low-level transcutaneous electrical stimulation of the auricular branch of vagus nerve ameliorates left ventricular remodeling and dysfunction by downregulation of matrix metalloproteinase 9 and transforming growth factor β1

Vagus nerve stimulation improves left ventricular (LV) remodeling by downregulation of matrix metalloproteinase 9 (MMP-9) and transforming growth factor β1 (TGF-β1). Our previous study found that low-level transcutaneous electrical stimulation of the auricular branch of the vagus nerve (LL-TS) could be substituted for vagus nerve stimulation to reverse cardiac remodeling. So, we hypothesize that LL-TS could ameliorate LV remodeling by regulation of MMP-9 and TGF-β1 after myocardial infarction (MI). Twenty-two beagle dogs were randomly divided into a control group (MI was induced by permanent ligation of the left coronary artery, n = 8), an LL-TS group (MI with long-term intermittent LL-TS, n = 8), and a normal group (sham ligation without stimulation, n = 6). At the end of 6 weeks follow-up, LL-TS significantly reduced LV end-systolic and end-diastolic dimensions, improved ejection fraction and ratio of early (E) to late (A) peak mitral inflow velocity. LL-TS attenuated interstitial fibrosis and collagen degradation in the noninfarcted myocardium compared with the control group. Elevated level of MMP-9 and TGF-β1 in LV tissue and peripheral plasma were diminished in the LL-TS treated dogs. LL-TS improves cardiac function and prevents cardiac remodeling in the late stages after MI by downregulation of MMP-9 and TGF-β1 expression.

Enalapril in Combination with Benznidazole Reduces Cardiac Inflammation and Creatine Kinases in Mice Chronically Infected with Trypanosoma cruzi

The protozoan Trypanosoma cruzi triggers an inflammatory process in mammalian heart causing events such as fibrosis, changes in the architecture and functionality in this organ. Enalapril, an angiotensin II-converting enzyme inhibitor, is a drug prescribed to ameliorate this heart dysfunction, and appears to exert a potential role in immune system regulation. Our aim was to evaluate the chronic cardiac inflammatory parameters after therapeutic treatment with enalapril and benznidazole in C57BL/6 mice infected with the VL-10 strain of T. cruzi. After infection, animals were treated with oral doses of enalapril (25 mg/kg), benznidazole (100 mg/kg), or both during 30 days. Morphometric parameters and levels of chemokines (CCL2, CCL5), IL-10, creatine kinases (CKs), and C-reactive protein were evaluated in the heart and serum at the 120th day of infection. Enalapril alone or in combination with benznidazole did not change the number of circulating parasites, but reduced cardiac leukocyte recruitment and total collagen in the cardiac tissue. Interestingly, the combination therapy (enalapril/benznidazole) also reduced the levels of chemokines, CK and CK-MB, and C-reactive proteins in chronic phase. In conclusion, during the chronic experimental T. cruzi infection, the combination therapy using enalapril plus benznidazole potentiated their immunomodulatory effects, resulting in a low production of biomarkers of cardiac lesions.

Effect of Ginkgo biloba extract on experimental cardiac remodeling

Background

To investigate the ameliorated effects of an extract of Ginkgo biloba extract (GBE) on experimental cardiac remodeling in rats induced by acute cardiac infarction, and further explore the mechanism concentrated on myocardial type I collagen, transforming growth factor beta 1 (TGF-β1), matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9), and provide the experimentaldata for clinical application of GBE.

Methods

Rats were divided into five groups (n = 20) as following: sham operation group (group A), acute myocardial infarction model group (group B), acute myocardial infarction model + aspirin (10 mg/kg) treatment group (group C), acute myocardial infarction model + captopril (20 mg/kg) treatment group (group D) and acute myocardial infarction model + Ginkgo biloba extract (100 mg/kg) treatment group (group E). The rat acute myocardial infarction model was reproduced by ligaturing the left anterior descending artery excluding the sham operation group which did not ligation only completed the operational process. Each group was further subdivided into treatment regimens lasting 4 weeks and 8 weeks. Immunohistochemistry and real-time polymerase chain reaction (PCR) methods were used to detect the protein expression and mRNA transcriptional levels of rat myocardial TGF-β1, type I collagen, MMP-2 and MMP-9.

Results

Compared with group B, regardless of the length of treatment (4 or 8 weeks), the TGF-β1, MMP-2 and MMP-9 mRNA transcriptional levels, and the protein expression levels of type I collagen, MMP-2 and MMP-9 in groups D, C and E were significantly decreased (P < 0.01). Furthermore, the mRNA expression levels of TGF-β1 in groups D, C and E were significantly lower after 8 weeks compared to after 4 weeks (P < 0.01), as were the expression levels of type I collagen in groups D, C and E (P < 0.05). There was no statistically significant difference in the protein expression levels of MMP-2 and MMP-9 between groups E and C.

Conclusions

GBE could inhibit experimental rat myocardial remodeling after acute myocardial infarction via reduced transcription of TGF-β1, MMP-2 and MMP-9 genes and by the decreased expression of type I collagen, MMP-2 and MMP-9 proteins in myocardial cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0719-z) contains supplementary material, which is available to authorized users.