The rescue potentials of OPC-41061, OPC-31260 and OPC-21268 on mutant AVPR2s that cause nephrogenic diabetes insipidus

Abstract

Purpose Nephrogenic Diabetes insipidus (NDI) is a rare disease which is characterized by polyuria and polydipsia. AVPR2 mutations can cause NDI. Mutants may not function properly since the mutations can affect their folding process and make them be trapped in the Endoplasmic reticulum (ER). Recent studies showed that pharmacological chaperones (PCs) may rescue mutant AVPR2s and they can be functional again. OPC-41061, OPC-31260 and OPC-21268 are these kind of PCs and they can specifically bind to the mutant AVPR2s and rescue them from ER via helping their folding process. In this study, the effects of OPC-41061, OPC-31260 and OPC-21268 on AVPR2 mutants (R68W, ΔR67-G69/G107W, V162A and T273M) were analyzed. Methods We performed cell surface and total ELISA, and cAMP accumulation assay for mutant AVPR2s after the treatment with 3 different PCs. Results It was observed that OPC-41061 improved cell surface expressions of all mutants except V162A and ΔR67-G69/G107W, and cell surface expressions of R68W and ΔR67-G69 were increased with all three PCs. Then mutants were stimulated with their agonists to measure cAMP accumulation in the cell as a functional analysis. As a result, we found that R68W and ΔR67-G69 (except T273M) were rescued and could be functional after the treatment with OPC-41061 and OPC-31260. Conclusion Showing specific rescue potential of these kind of PCs has an importance on the development of new treatment strategies on NDI. Determining the responses of mutant proteins to various chaperones is extremely important for current treatment approaches and identifying the new PCs.