Corrigendum to “Brain uptake pharmacokinetics of incretin receptor agonists showing promise as Alzheimer's and Parkinson's disease therapeutics” [Biochem. Pharmacol. 180 (2020) 114187] (Biochemical Pharmacology (2020) 180, (S0006295220304238), (10.1016/j.bcp.2020.114187))

Abstract

While preparing a follow-up to our earlier report published in Biochemical Pharmacology 180: 114187 (2020), we became aware of a mistake in the numerical nomenclature for 2 of the peptides studied in that work. The peptides in question were originally created by Finan and Ma et al. (Science Translational Medicine 5, 209ra151, 2013) to discover single peptides that can potently, selectively, and equally activate receptors for 2 incretin receptors (i.e., glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIPR]). Such drugs are called balanced dual incretin receptors agonists (IRAs). We were interested in testing brain uptake of the unmodified, acylated, and PEGylated versions of the peptide Finan and Ma et al., (2013) found most successful as a balanced dual IRA. A senior author of the Finan and Ma et al. (2013) study (Dr. Richard D. DiMarchi) generously sent us samples of these peptides noting their key structural features but without a numerical nomenclature. The unmodified protein, the backbone for the acylated and PEGylated version, was unambiguously identified as compound 17 in the text and Peptide 17 in the second column of Table 1 of Finan and Ma et al. (2013) based on the text description and the listed balance of GLP-1R and GIPR activation. Using the second column of the same table, we assumed that the acylated and PEGylated versions of Peptide 17 were respectively Peptides 18 and 20 of Finan and Ma et al. (2013), but that was ambiguous because two peptides in that table are called “Peptide 18” and because Peptide 20 is also identified as compound 21 in the first column of the same table. We should have noticed that the text of Finan and Ma et al. (2013) clarifies the numerical nomenclature for the acylated and PEGylated peptides and that unambiguous numbering of them is given in their Supplemental Fig. 1, which provides the amino acid sequence of all the peptides they synthesized. Based on that supplemental figure, what we called Peptides 18 and 20 in Salameh et al. (2020) are actually Peptides 19 and 21 of Finan and Ma et al. (2013), respectively. To remove any confusion regarding the identity of the peptides tested, we provide corrected tables and figures in Salameh et al. (2020). In these tables and figures we use exenatide in place of exendin-4 because we tested the synthetic form of exendin-4 and refer to DA-JC4 as DA4-JC to comply with its more recent nomenclature. No corrections are needed in Fig. 5. The corrected figures and tables are as follows: Corrected Fig. 1:[Formula presented] Corrected Fig. 2:[Formula presented] Corrected Fig. 3:[Formula presented] Corrected Fig. 4:[Formula presented] Corrected Table 1: Table 1. Characteristics of IRA Peptides Studied. [Table presented] Corrected Table 2: Table 2. In Vivo Degradation of 125I-IRA Peptides.* [Table presented] Corrected Table 3: Table 3. Pharmacokinetics of 125I-IRA Peptides. [Table presented] Corrected Table 4: Table 4. Saturability of 125I-IRA Peptide Transport into Brain*. [Table presented]