Block Copolymer Nanomicelle-Encapsulated Curcumin Attenuates Cerebral Ischemia Injury and Affects Stem Cell Marker Expression by Inhibiting lncRNA GAS5.

Stroke has become the most common cause of death among residents in China, among which ischemic stroke accounts for the vast majority reaching 70% to 80%. It is of great importance to actively investigate the protective mechanism of cerebral ischemia injury after IS (ischemic stroke). We constructed cerebral ischemia injury models in vivo MACO rat and in vitro (oxygen-glucose deprivation cell model) and set up different interference groups. RT-PCR (reverse transcription PCR) was conducted to detect the expression of lncRNA in neuronal cells, brain tissue, and plasma of different groups, and ELISA (enzyme-linked immunosorbent assay) and western blot were used to detect the expression of the protein in neuronal cells, brain tissue, and plasma of different groups. Cell activity was detected by the CCK-8 assay, while cell apoptosis was examined by TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. In the rats' neuronal cells and brain tissue, curcumin can inhibit the expression of lncRNA GAS5 (long noncoding RNA growth arrest-specific 5). In oxygen-glucose-deprived neuronal cells in vitro, curcumin and low-expressed lncRNA GAS5 can enhance cell activity and decline cell apoptosis, but the addition of curcumin and overexpressed lncRNA GAS5 can make this phenomenon disappear. In neuronal cells, plasma, and brain tissue, curcumin and the low-expressed lncRNA GAS5 can inhibit the expression of IL-1β (interleukin 1 beta), TNF-α (tumor necrosis factor alpha), IL-6 (interleukin 6), Sox2 (SRY-box transcription factor 2), Nanog, and Oct4 (octamer-binding transcription factor 4). However, overexpressed lncRNA GAS5 and curcumin made the inhibitory effect disappear. In conclusion, this study demonstrated that curcumin could inhibit the expression of lncRNA GAS5, thereby inhibiting the expression of inflammation-related factors IL-1β, TNF-α, and IL-6, and ultimately achieve the purpose of attenuating cerebral ischemic cell damage. However, curcumin and lncRNA GAS5 may not alleviate cerebral ischemic cell damage by affecting stem cell differentiation.