MPFC TNFR2 modulated the impairment of cognitive flexibility induced by adolescent social stress and the relevant neuroplastic molecules

Abstract

The impairment of cognitive flexibility (CF) exists to varying degrees in several psychiatric disorders and is increasingly recognized as the important etiological and pathological factors in these disorders. Our previous research has demonstrated that adolescent social stress (ASS) can lead to cognitive dysfunction in adult mice, accompanied by immune changes in the medial prefrontal cortex (mPFC), mainly manifested by reduced levels of cytokine TNFα. The present study aimed to further investigate the mechanisms of TNFα receptor and the downstream neuroplasticity-related molecules involved in cognitive dysfunction induced by ASS. Cognitive flexibility was assessed using Attentional Set Shifting Task (AST). Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) methods were use to determine mRNA and protein level of TNFα receptor (TNFR) and downstream signaling molecules, including nuclear transcript factor NF-κB and CREB, pCREB and Brain-derived neurotrophic factor (BDNF). We found that ASS significantly decreased the mRNA and protein expression of TNFα receptor 2 (TNFR2), but not TNFR1 of the mPFC in adult mice. Direct up-regulation TNFR2 expression by microinjection of adeno-associated virus (AAV) encoding TNFR2 into the mPFC reversed the impairment of CF and the decrease of BDNF protein levels in stressed adult mice compared to that in controls. These findings demonstrated that mPFC TNFR2 plays critical roles in cognitive inflexibility induced by ASS, which effects may be mediated by neuroplastic molecules, and could be a promising target for treating cognitive dysfunction in psychiatric disorders.