Platelet rich plasma alleviates OGD/R injury in N2a cell by enhancing autophagy through the miR­223/PAQR3 pathway.

Our study constructed an in vitro model of cerebral ischemia/reperfusion (I/R) injury to evaluate the protective effect of platelet rich plasma (PRP) on I/R injury and uncover the mechanism behind it. Firstly, N2a cells were exposed in the condition of oxygen and glucose deprivation/reperfusion (OGD/R) to construct a model of cerebral I/R in vitro. MTT assay was employed to access the effects of PRP in N2a cell OGD/R injury. Then, we evaluated the role of the expression of miR­223, progestin and adipoQ receptors 3 (PAQR3) and autophagy markers in the neuroprotective effect of PRP by qPCR and western blot. And the effect of miR­223/PAQR3 axis regulated autophagy in the neuroprotection of PRP was verified by overexpressing miR­223 and PAQR3. Finally, the interaction between miR­223 and PAQR3 was analyzed by the luciferase reporter gene. The results showed that after OGD/R treatment of N2a cells, the expression of miR­223 increased and the expression of PAQR3 and autophagy decreased. PRP improved cells damage caused by OGD/R in N2a cell, and reduced the expression of miR­223 in cells, increased PAQR3 and autophagy. The luciferase reporter assay was used to prove that miR­223 could target PAQR3 directly. Overexpression of miR­223 could eliminate the improvement effect of PRP on OGD/R cells, but at the same time, overexpression of PAQR3 restored the protection of PRP from cell damage. Our research found that in the OGD/R injury in vitro model, PRP inhibited the expression of miR­223 and enhanced autophagy to attenuate the injury by increasing the expression of PAQR3.

Action of trichostatin A on Alzheimer's disease-like pathological changes in SH-SY5Y neuroblastoma cells.

The histone deacetylase inhibitor, trichostatin A, is used to treat Alzheimer's disease and can improve learning and memory but its underlying mechanism of action is unknown. To determine whether the therapeutic effect of trichostatin A on Alzheimer's disease is associated with the nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like epichlorohydrin-related protein-1 (Keap1) signaling pathway, amyloid ß-peptide 25-35 (Aß25-35) was used to induce Alzheimer's disease-like pathological changes in SH-SY5Y neuroblastoma cells. Cells were then treated with trichostatin A. The effects of trichostatin A on the expression of Keap1 and Nrf2 were detected by real-time quantitative polymerase chain reaction, western blot assays and immunofluorescence. Total antioxidant capacity and autophagy activity were evaluated by total antioxidant capacity assay kit and light chain 3-I/II levels, respectively. We found that trichostatin A increased cell viability and Nrf2 expression, and decreased Keap1 expression in SH-SY5Y cells. Furthermore, trichostatin A increased the expression of Nrf2-related target genes, such as superoxide dismutase, NAD(P)H quinone dehydrogenase 1 and glutathione S-transferase, thereby increasing the total antioxidant capacity of SH-SY5Y cells and inhibiting amyloid ß-peptide-induced autophagy. Knockdown of Keap1 in SH-SY5Y cells further increased trichostatin A-induced Nrf2 expression. These results indicate that the therapeutic effect of trichostatin A on Alzheimer's disease is associated with the Keap1-Nrf2 pathway. The mechanism for this action may be that trichostatin A increases cell viability and the antioxidant capacity of SH-SY5Y cells by alleviating Keap1-mediated inhibition Nrf2 signaling, thereby alleviating amyloid ß-peptide-induced cell damage.