Role of mPFC DUSP1 in regulating the sensitivity to cocaine in adolescent cocaine-exposed mice of adulthood

Abstract

Adolescent cocaine abuse increases the risk for developing addiction in later life, which remains a big public health concern, but the underlying molecular mechanism is poorly understood. Here, adolescent cocaine-exposed (ACE) male mice models were established by administrating cocaine during adolescent period. When growing to adult age, mice were subjected to conditioned place preference (CPP) to evaluate the sensitivity to cocaine, then potential molecule of dual specificity phosphatase 1 (DUSP1) were screened out by transcriptomic sequencing. Subthreshold dose of cocaine (sdC), that is insufficient to produce CPP, was used to induce CPP in adulthood. The sdC treatment effectively induced CPP in ACE mice during adulthood, accompanied with the more triggered CaMKII-positive neurons, and induced higher Dusp1 gene, lower DUSP1 protein, lower DUSP1 activity and lower DUSP1 expression on CaMKII-positive neurons (DUSP1CaMKII) in medial prefrontal cortex (mPFC). Overexpressing DUSP1CaMKII suppressed CaMKII-positive neuronal activation, and ultimately blocked sdC-induced CPP in ACE mice during adulthood. While, knocking-down DUSP1CaMKII activated more CaMKII-positive neurons, and aggravated sdC-preferred behavior in ACE mice during adulthood. ERK1/2 might be potential subsequent signal for DUSP1 in the process. Collectively, our findings reveal a novel molecular mechanism underlying adolescent drug abuse-induced susceptibility to addiction during adulthood, and mPFC DUSP1CaMKII is a promising pharmacological target to predict or treat addiction, especially caused by adolescent substance use. SummaryAdolescent cocaine exposure causes higher cocaine-preferred behaviors during adulthood, along with evoked mPFC activity in response to cocaine challenge. Locally overexpressing but not knocking-down the dual specificity phosphatase 1 (DUSP1) on CaMKII-positive neurons (DUSP1CaMKII) suppresses mPFC activation, and ultimately rescues the higher sensitivity to cocaine during adulthood.