Effects of dexmedetomidine on cognitive dysfunction and neuroinflammation via the HDAC2/HIF-1 alpha/PFKFB3 axis in a murine model of postoperative cognitive dysfunction

Inhibition of histone deacetylase (HDAC) may be a useful approach in the treatment of disorders characterized by cognitive dysfunction. Dexmedetomidine (DEX), an alpha 2-adrenoceptor (alpha 2-AR) agonist, has demonstrated neuroprotective effects. Here, we attempted to investigate the protective effects of DEX on postoperative cognitive dysfunction (POCD) involving HDAC2. Male C57BL/6 mice were selected to develop a POCD model, where HDAC2, HIF-1 alpha, and PFKFB3 expression was quantified. DEX was administered before POCD modeling. Then the cognitive function of POCD mice was evaluated with the open field and Y-maze tests. Meanwhile, lipopolysaccharide (LPS) was employed to induce BV-2 microglial cells to simulate the inflammatory response. The contents of TNF-alpha, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA) in mouse serum and BV-2 cell supernatant. Abundant expression of HDAC2, HIF-1 alpha, and PFKFB3 was confirmed in POCD mice (p < 0.05). Cognitive dysfunction in POCD mice could be alleviated following pharmacological inhibition of HDAC2 by FK228 (p < 0.05). Mechanistically, HDAC2 upregulated HIF-1 alpha and PFKFB3 and promoted the secretion of inflammatory factors in LPS-exposed BV-2 cells (p < 0.05). DEX attenuated neuroinflammation and the resulting cognitive dysfunction by decreasing HDAC2 expression and HIF-1 alpha-dependent PFKFB3 upregulation in POCD mice (p < 0.05). In conclusion, DEX-regulated HDAC2 may play an inhibitory role in mice with POCD through regulation of the HIF-1 alpha/PFKFB3 axis.