Comparative beneficial effects of nebivolol and nebivolol/valsartan combination against mitochondrial dysfunction in angiotensin II-induced pathology in H9c2 cardiomyoblasts

Comparison of the Protective Effects of Nebivolol and Metoprolol against LPS-Induced Injury in H9c2 Cardiomyoblasts

Here, we, for the first time, compared the cardioprotective effects of third-generation vasodilating beta-blocker nebivolol (Neb) and conventional beta-blocker metoprolol (Met) on LPS-induced injury in H9c2 cardiomyoblasts. Our findings denoted that Neb and Met pretreatment diminish LPS-mediated cytotoxicity and oxidative stress. Concomitantly, LPS-triggered inflammatory cytokines activation was significantly suppressed by Neb but not by Met. Pretreatment with either Neb or Met alleviated LPS-mediated mitochondrial impairment by enhancing the expression of genes related to its biogenesis such as PGC-1α, NRF1, and TFAM. On the contrary, Neb but not Met-upregulated mitochondrial fusion-related genes such as OPA, and MFN2. In summary, our findings suggest that Neb and Met treatment significantly ameliorated the LPS-induced cytotoxicity and oxidative stress. Additionally, these findings suggest that Neb but not Met significantly down-regulates LPS-induced proinflammatory factors, probably by enhancing mitochondrial biogenesis and fusion.

Nebivolol versus placebo in patients undergoing anthracyclines (CONTROL Trial): rationale and study design

AIMS

Anthracyclines are the chemotherapeutic agents most frequently associated with cardiotoxicity, while remaining widely used. Different neurohormonal blockers have been tested as a primary prevention strategy to prevent or attenuate the onset of cardiotoxicity, with mixed results. However, prior studies were often limited by a nonblinded design and an assessment of cardiac function based only on echocardiographic imaging. Moreover, on the basis of an improved mechanistic understanding of anthracycline cardiotoxicity mechanisms, new therapeutic strategies have been proposed. Among cardioprotective drugs, nebivolol might be able to prevent the cardiotoxic effects of anthracyclines, through its protective properties towards the myocardium, endothelium, and cardiac mitochondria. This study aims to evaluate the cardioprotective effects of the beta blocker nebivolol in a prospective, placebo-controlled, superiority randomized trial in patients with breast cancer or diffuse large B cell lymphoma (DLBCL) who have a normal cardiac function and will receive anthracyclines as part of their first-line chemotherapy programme.

METHODS

The CONTROL trial is a randomized, placebo-controlled, double-blinded, superiority trial. Patients with breast cancer or a DLBCL, with a normal cardiac function as assessed by echocardiography, scheduled for treatment with anthracyclines as part of their first-line chemotherapy programme will be randomized 1 : 1 to nebivolol 5 mg once daily (o.d.) or placebo. Patients will be examined with cardiological assessment, echocardiography and cardiac biomarkers at baseline, 1 month, 6 months and 12 months. A cardiac magnetic resonance (CMR) assessment will be performed at baseline and at 12 months. The primary end point is defined as left ventricular ejection fraction reduction assessed by CMR at 12 months of follow-up.

CONCLUSION

The CONTROL trial is designed to provide evidence to assess the cardioprotective role of nebivolol in patients undergoing chemotherapy with anthracyclines.

CLINICAL TRIAL REGISTRATION

The study is registered in the EudraCT registry (number: 2017-004618-24) and in the ClinicalTrials.gov registry (identifier: NCT05728632).

Protective Effects of Nanoceria against Mitochondrial Dysfunction and Angiotensin II-Induced Hypertrophy in H9c2 Cardiomyoblasts

Mitochondrial dysfunction triggered by increased reactive oxygen species (ROS) generation is involved in the pathogenesis and development of cardiac hypertrophy. Nanoceria (cerium oxide nanoparticle) has powerful ROS-scavenging properties and is considered a potential therapeutic option for curbing ROS-related disorders. Here, we explored the signaling mechanism underlying the protective effects of nanoceria against angiotensin (Ang) II-stimulated pathological response in H9c2 cardiomyoblasts. Our data revealed that pretreatment of H9c2 cardiomyoblasts with nanoceria significantly prevented Ang II-stimulated generation of intracellular ROS, aberrant expression of pro-inflammatory cytokines, and hypertrophy markers. Nanoceria pretreatment increased the mRNA levels of genes regulating the cellular antioxidant defense system (SOD2, MnSOD, CAT) in Ang II-treated cells. Furthermore, nanoceria restored mitochondrial function by decreasing mitochondrial ROS, increasing mitochondrial membrane potential (MMP), and promoting the mRNA expression of genes associated with mitochondrial biogenesis (PGC-1α, TFAM, NRF1, and SIRT3) and mitochondrial fusion (MFN2, OPA1). Collectively, these findings demonstrate the protective effects of nanoceria against Ang II-mediated mitochondrial dysfunction and pathological hypertrophy in H9c2 cells.

Inhibition of eNOS Partially Blunts the Beneficial Effects of Nebivolol on Angiotensin II-Induced Signaling in H9c2 Cardiomyoblasts

We have recently illustrated that nebivolol can inhibit angiotensin II (Ang II)-mediated signaling in cardiomyoblasts; however, to date, the detailed mechanism for the beneficial effects of nebivolol has not been studied. Here, we investigated whether the inhibition of NO bioavailability by blocking eNOS (endothelial nitric oxide synthase) using L-NG-nitroarginine methyl ester (L-NAME) would attenuate nebivolol-mediated favorable effects on Ang II-evoked signaling in H9c2 cardiomyoblasts. Our data reveal that the nebivolol-mediated antagonistic effects on Ang II-induced oxidative stress were retreated by concurrent pretreatment with L-NAME and nebivolol. Similarly, the expressions of pro-inflammatory markers TNF-α and iNOS stimulated by Ang II were not decreased with the combination of nebivolol plus L-NAME. In contrast, the nebivolol-induced reduction in the Ang II-triggered mTORC1 pathway and the mRNA levels of hypertrophic markers ANP, BNP, and β-MHC were not reversed with the addition of L-NAME to nebivolol. In compliance with these data, the inhibition of eNOS by L-N⁵-(1-Iminoethyl) ornithine (LNIO) and its upstream regulator AMP-activated kinase (AMPK) with compound C in the presence of nebivolol showed effects similar to those of the L-NAME plus nebivolol combination on Ang II-mediated signaling. Pretreatment with either compound C plus nebivolol or LNIO plus nebivolol showed similar effects to those of the L-NAME plus nebivolol combination on Ang II-mediated signaling. In conclusion, our data indicate that the rise in NO bioavailability caused by nebivolol via the stimulation of AMPK/eNOS signaling is key for its anti-inflammatory and antioxidant properties but not for its antihypertrophic response upon Ang II stimulation.