Short-Term Proteasome Inhibition: Assessment of the Effects of Carfilzomib and Bortezomib on Cardiac Function, Arterial Stiffness, and Vascular Reactivity.

Simple Summary: Proteasome inhibitors, such as bortezomib and carfilzomib, are vital for treating relapsed or refractory multiple myeloma, but their potential link to cancer therapy-related cardiovascular dysfunction (CTRCD) raises concerns. Bortezomib, a reversible first-generation inhibitor, and carfilzomib, a second-generation irreversible inhibitor, have been associated with hypertension, heart failure, and arrhythmias. This study explored their impact on cardiac function, focusing on left ventricular ejection fraction (LVEF), and vascular function through arterial stiffness and vascular reactivity assessments. Twelve-week-old male mice were treated with either carfilzomib or bortezomib, with some receiving L-NAME to induce hypertension. Echocardiography was used to evaluate cardiac and vascular parameters at different time points, followed by ex vivo arterial stiffness and reactivity measurements. Results showed no significant changes in arterial stiffness at baseline pressures, but a steeper pressure-stiffness curve was noted in carfilzomib-treated normotensive and hypertensive mice. Carfilzomib also showed a trend toward reduced LVEF in hypertensive mice, with bortezomib showing similar trends. Vascular reactivity remained largely unchanged, but proteasome inhibition appeared to enhance endothelial-independent relaxation. Overall, short-term treatment with both drugs was deemed relatively safe under the tested conditions. Proteasome inhibitors such as bortezomib and carfilzomib induce apoptosis and are a cornerstone in the treatment of relapsed or refractory multiple myeloma. However, concerns have emerged concerning their link to cancer therapy-related cardiovascular dysfunction (CTRCD). Bortezomib, a reversible first-generation inhibitor, and carfilzomib, a second-generation irreversible inhibitor, are associated with hypertension, heart failure, and cardiac arrhythmias. The current study investigated the effects of bortezomib and carfilzomib on cardiac (left ventricular ejection fraction, LVEF) and vascular (arterial stiffness, vascular reactivity) function. Cardiac function assessment aimed to build upon existing evidence of proteasome inhibitors CTRCD, while arterial stiffness served as an early indicator of potential vascular remodeling. Groups of 12-week-old C57BL/6J male mice (n = 8 per group) were randomly assigned to receive vehicle, carfilzomib (8 mg/kg I.P.), or bortezomib (0.5 mg/kg I.P.). Additionally, proteasome inhibition was assessed in mice treated with L-NAME (0.5 mg/kg) to induce hypertension. Cardiac and vascular parameters were evaluated via echocardiography on days 0 and 3. On day 6, mice were sacrificed for ex vivo analysis of arterial stiffness and vascular reactivity. Overall, no changes in arterial stiffness were detected either in vivo or ex vivo at basal pressures. However, a steeper pressure–stiffness curve was observed for carfilzomib in normotensive (p < 0.01) and hypertensive (p < 0.0001) mice ex vivo. Additionally, in hypertensive mice, carfilzomib decreased LVEF (p = 0.06), with bortezomib exhibiting similar trends. Vascular reactivity remained largely unchanged, but proteasome inhibition tended to enhance endothelial-independent relaxations in both control and hypertensive mice. In conclusion, short-term treatment with carfilzomib and bortezomib is considered relatively safe for the protocols assessed in the study. [ABSTRACT FROM AUTHOR]