3.7. D-allose inhibits TLR4/ PI3K/AKT signaling to attenuate neuroinflammation and apoptosis via inhibiting Gal-3 after MCAO/R injury
Based on our novel findings of the neuroprotection of D-allose associated with Gal-3 and TLR4/ PI3K/AKT signaling pathway in vitro, we stereotactically injected AAV-based shRNA Gal-3 into the cortex area of mice before MCAO/R. Firstly, compared with the MCAO/R+sh-Nc group, the mRNA and protein level of Gal-3 was decreased in Gal-3 KO mice after MCAO/R injury (P <0.01, Fig 7A-C). Then, the results showed that the down-regulation of Gal-3 attenuated the infraction volume ratio and brain edema of mice and enhanced the protective effects of D-allose. Similar to the infraction volume ratio, the same results about neurological deficits were observed in different groups (P <0.01, Fig 7 D-F). Moreover, compared with wild-type mice following MCAO/R injury, after treatment with D-allose, Gal-3 KO mice had significantly increased phosphorylation levels of PI3K and AKT and reduced expression levels of Gal-3 and TLR4 (P <0.01, Fig 7 G). The above mice also decreased the levels of cleaved Caspase3, cleaved Caspase1(Fig 7G) and TUNEL-positive cells, IL-1β, IL-6 and TNF-α(Fig 7H-K). Combined with the above data of cells, these results all suggested that D-allose inhibits TLR4/PI3K/AKT signaling to attenuate neuroinflammation and apoptosis, and ameliorate neurological deficit via depressing Gal-3 under the conditions of secondary injury of IS.