The CUL3/neddylation inhibitor MLN4924 reduces ethanol-induced locomotor sensitization and inflammatory pain allodynia in mice.

Ding Z

Ding Z(1), Knipp GT(2), van Rijn RM(3), Chester JA(4), Watts VJ(5).
Author information:
(1)Dept of Medicinal Chemistry & Molecular Pharmacology, Purdue University, West Lafayette, IN, 47907, USA.
(2)Dept of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA.
(3)Dept of Medicinal Chemistry & Molecular Pharmacology, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA.
(4)Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA; Dept of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
(5)Dept of Medicinal Chemistry & Molecular Pharmacology, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA. Electronic address: [Email]

https://dx.doi.org/10.1016/j.bbr.2020.113051

Heterologous sensitization of adenylyl cyclase (AC) is defined by an enhanced cAMP response following persistent activation of Gαi/o-coupled receptors. This phenomenon was first observed in cellular models, and later reported in animal models of inflammatory pain or following chronic exposure to drugs of abuse including opioids and cocaine. Recently, we used genome-wide siRNA screening to identify Cullin3 signaling as a mediator of AC sensitization in cellular models. We also showed that pharmacological inhibition of Cullin3 with the neddylation inhibitor, MLN4924, abolished heterologous sensitization of several AC isoforms, including AC1, AC2, AC5, and AC6. Because ACs, especially AC1, have been implicated in alcohol-induced locomotor sensitization and inflammatory pain, we assessed the potential activity of MLN4924 in both murine models. We found that MLN4924 (30 mg/kg, i.p.) accumulated in the brain and reduced both locomotor sensitization induced by repeated alcohol administration and allodynia in an inflammatory pain model. Based on our previous findings that MLN4924 potently blocks AC sensitization in cellular models, we propose that the activity of MLN4924 in both animal models potentially occurs through blocking AC sensitization. Our findings provide the basis for understanding the molecular mechanism and yield a new pathway for drug development for pathological disorders associated with AC sensitization.