I am a
Home I AM A Search Login

Papers of the Week

Papers: 2 Mar 2024 - 7 Mar 2024

2024 Mar 02

Int Immunopharmacol



The activation of RARα prevents surgery-induced cognitive impairments via the inhibition of neuroinflammation and the restoration of synaptic proteins in elderly mice.


Chen Y, Zhou Y, Cai J, Xu J, Hu C, Chen H, Hong Y, Pan N, Jiang Y, Zhou C, Wei H, Xu Z, Liu L, Wu X, Cui W


Post-operative cognitive dysfunction (POCD) is a multi-etiological symptom mainly occurred in elderly people after surgery. The activation of retinoic acid receptor α (RARα), a transcriptional factor, was previously predicated to be negatively associated with the occurrence of POCD. However, the mechanisms underlying anti-POCD effects of RARα were still unclear. In this study, AM580, a selective agonist of RARα, and all-trans-retinoic acid (ATRA), a pan agonist of RAR, significantly alleviated cognitive dysfunction and increased the expression of RARα in elderly mice after surgery, which was decreased by RO41-5253, an antagonist of RARα. A bioinformatic study further predicted that the activation of RARα might produce anti-POCD effects via the restoration of synaptic proteins. Both agonists inhibited the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (Myd88) and the phosphorylation of nuclear factorkappa-B (NF-κB), leading to the prevention of microglial over-activation and pro-inflammatory cytokines secretion in the hippocampal regions of elderly mice after surgery. Moreover, AM580 and ATRA increased the expression of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95), and the phosphorylation of extracellular signal-regulated kinase (ERK) and cAMP-response element binding protein (CREB). All these results suggested that the activation of RARα prevented surgery-induced cognitive impairments via the inhibition of neuroinflammation by the reduction of the TLR4/Myd88/NF-κB pathway and the restoration of synaptic proteins by the activation of the BDNF/ERK/CREB pathway, providing a further support that RARα could be developed as a therapeutic target for POCD.