Abstract | November 17, 2023
Novel Alpha-Calcitonin Gene Related Peptide Agonist Analogs in the Treatment of Cardiovascular Disease
Learning Objectives
- The need for novel therapy for the treatment of cardiovascular diseases - Despite the several classes of drugs available for cardiovascular diseases, it remains the number one cause of death of individuals, not only in the Unites States, but also globally. Therefore, it is evident that the development of novel therapeutic agents are not only necessary but soon to be inevitable in order to combat the rising trends seen in CVDs.
- Utilization of alpha-calcitonin gene related peptide (α-CGRP) for the treatment of cardiovascular disease - Alpha-calcitonin gene related peptide (α-CGRP) is a 37 amino acid anti-inflammatory vasodilator neuropeptide. Pre-clinical studies have proven that the peptide protects against a variety of heart diseases such as heart failure and hypertension. Hence, it can be translated as a therapeutic agent to treat these diseases.
- Development of stable bioactive agonist analogs of alpha-calcitonin gene related peptide (α-CGRP) for the treatment of cardiovascular disease - Native α-CGRP half-life is very short due to its rapid degradation via protease; therefore, it has been difficult to use previously as a therapeutic agent. We are using a peptoid chemistry approach to develop stable bioactive α-CGRP agonist analogs. We chemically linked two molecules of N-methoxyethylglycine (NMEG) to either the N-terminal end (N-ter NMEG-CGRP) or C-terminal end (C-ter NMEG-CGRP) of the peptide. The peptide-peptoid hybrid containing N-ter NMEG-CGRP proved to be both non-toxic and bioactive and therefore, it is a promising α-CGRP agonist analog to use as a novel therapy for cardiovascular diseases such as heart failure and hypertension.
Background
As a potent vasodilator neuropeptide, alpha-calcitonin gene related peptide (α-CGRP) possesses cardioprotective effects. In animal models, α-CGRP has demonstrated such effects in a variety of cardiac diseases including heart failure, hypertension and myocardial infraction. This suggests that α-CGRP is a potential drug candidate for the treatment of cardiac diseases; however, low bioavailability of the peptide negates this possibility.
Methods
In order to develop stable protease-resistant α-CGRP analogs, we used a peptoid chemistry approach and chemically synthesized two α-CGRP analogs linking two molecules of N-methoxyethylglycine (NMEG) peptoid molecules to either the N-terminal end (N-ter NMEG-CGRP) or C-terminal end (C-ter NMEG-CGRP) of the peptide. A peptoid is a N-substituted glycine molecule in which the side chain is attached on the nitrogen atom rather than the α-carbon atom. Both peptoid-peptide hybrids (at concentrations 1 µM, 3 µM, and 10 µM) were incubated for 4 days with rat H9c2 cardiac cells and their toxicity was measured using MTT-cell viability assay. Our results demonstrated that both peptoid-peptide hybrids did not affect the viability of the cardiac cells. To test if these peptides were bioactive, a subcutaneous injection of either peptide (at dose 1.2, 3.6, and 12 (mg/kg b.wt. per mouse) was given to male C57BL6 mice (n= 4 mice/dose) and mice blood pressure (BP) was measured at different time intervals using a tail-cuff BP analysis system.
Results
Our results demonstrated that both peptide-peptoid hybrids are non-toxic to cardiac cells and N-ter NMEG-CGRP reduced blood pressure in mice in a time-dependent manner. However, a reduction in BP was not observed when C-ter NMEG-CGRP was a subcutaneously injected in mice.
Conclusion
In summary, our results showed that although both peptoid-peptide hybrids (N-ter NMEG-CGRP and C-ter NMEG-CGRP) were non-toxic to H9c2 cardiac cells but only N-ter NMEG-CGRP is bioactive in mice. Therefore, N-ter NMEG-CGRP is a promising α-CGRP agonist analog to treat cardiovascular diseases.
References and Resources
- Ambrish Kumar, Maelee Williamson, Andrew Hess, Donald J DiPette, and Jay D Potts. Alpha- calcitonin gene-related peptide (α-CGRP): New therapeutic strategies for the treatment and prevention of cardiovascular disease and migration. Frontiers in Physiology, 2022, 13: 826122.
- Ambrish Kumar, Scott Supowit, Donald J DiPette, and Jay D Potts. Calcitonin gene-related peptide prevents pressure-overload induced heart failure: Role of apoptosis and oxidative stress. Physiological Reports, 2019, 7(21):e14269.
- Li, J., Levick, S. P., Dipette, D. J., Janicki, J. S., and Supowit, S. C. Alpha calcitonin gene-related peptide is protective against pressure overload-induced heart failure. Regulatory. Peptides, 2013, 185, 20 –28.
- Ronald N Zuckermann , Thomas Kodadek. Peptoids as potential therapeutics. Curr Opin Mol Ther, 2009, 11(3):299-307.
