TAT-tagging of VIP exerts positive allosteric modulation of the PAC1 receptor and enhances VIP neuroprotective effect in the MPTP mouse model of Parkinson's disease

• Published in: Biochimica et biophysica acta. General subjects Vol. 1864; no. 8; p. 129626
• Main Authors: Yu, Rongjie, Li, Junfeng, Lin, Zhuochao, Ouyang, Zehua, Huang, Xiaoling, Reglodi, Dora, Vaudry, David
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2020
• Subjects: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine - pharmacology; Allosteric Regulation - drug effects; animal models; Animals; bioassays; calorimetry; Cationic Argine-rich peptides (CARP); Cell Survival - drug effects; Cell-Penetrating Peptides - pharmacology; cyclic AMP; Disease Models, Animal; drugs; electrostatic interactions; Mice; neuropeptide receptors; Neuroprotective Agents - pharmacology; neuroprotective effect; Parkinson disease; Parkinson Disease - drug therapy; Parkinson Disease - metabolism; Parkinson Disease - pathology; Parkinson diseaseNeuroprotection; Parkinson's disease; Pituitary adenylate cyclase-activating polypeptide receptor 1 (PAC1); polypeptides; Positive allosteric modulation; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I - metabolism; TAT; titration; Tumor Cells, Cultured; vasoactive intestinal peptide; Vasoactive intestinal peptide (VIP); Vasoactive Intestinal Peptide - pharmacology; Parkinson's disease; CARP; TAT; MTT; MPP; VIP-TAT; T-turn; TUNEL; FBS; PAC1; Positive allosteric modulation; Pituitary adenylate cyclase-activating polypeptide receptor 1 (PAC1); HPLC; IOD; Vasoactive intestinal peptide (VIP); DOPAC; MALDI-TOF; PACPA; T-total; SOD; Cationic Argine-rich peptides (CARP); HVA; PD; Parkinson diseaseNeuroprotection; MPTP; VIP; DA
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2020.129626

The cationic Arginine-rich peptide (CARP) TAT had been tagged at the C-terminal end of the vasoactive intestinal peptide (VIP) to construct VIP-TAT in order to improve traversing ability. Interestingly, it was found that TAT may bind the positive allosteric modulation (PAM) site of the N-terminal extracellular domain of neuropeptide receptor PAC1 (PAC1-EC1), imitating the C-terminus part of pituitary adenylate cyclase-activating polypeptide (PACAP) PACAP(28–38) fragment. To test this hypothesis, we addressed the neuroprotective effects of VIP, VIP-TAT and PACAP38 in Parkinson's Disease (PD) cellular and mouse models. We also analyzed the peptides affinity for PAC1 and their ability to activate it. VIP-TAT had in vitro and in vivo neuroprotective effects much efficient than VIP in PD cellular and mouse models. The isothermal titration calorimetry (ITC) and competition binding bioassays confirmed that TAT binds PAC1-EC1 at the same site as PACAP(28–38). The cAMP experiments showed TAT-VIP results in a higher activation potency of PAC1 than VIP alone. The correlation of the peptides cationic properties with their affinity for PAC1 and their ability to activate the receptor, indicated that electrostatic interactions mediate the binding of TAT to the PAM domain of the PAC1-EC1, which induces the conformational changes of PAC1-EC1 required to promote the subsequent structural interaction and activation of the receptor with VIP. VIP-TAT has some potency for the development of a novel drug targeting neurodegenerative diseases. •TAT electrostatic interacts with the PAM site of PAC1•TAT enhances the activation on PAC1•TAT improves the CARPs properties of VIP