ABSTRACT
AIM: To clarify the modulation of autophagy in ischemic penumbra by hydroxysafflor yellow A ( HSYA) after cerebral ischemia/reperfusion ( I/R) injury.METHODS:Male SD rats subjected to transient middle cere-bral artery occlusion for 90 min were randomly divided into 4 groups:sham-operation (sham) group, cerebral I/R (I/R) group, I/R+HSYA group and sham+HSYA group.Modified neurological severity score (mNSS) was used to evaluate the neurological deficits of the rats at 6 h, 1 d, 3 d and 7 d after reperfusion , accompanied by the detection of autophagy , apoptosis and mRNA expression of IFN-βin ischemic penumbra .RESULTS:Compared with sham group , upregulation of LC3-Ⅱand degradation of SQSTM1/P62 were observed in I/R group, indicating the activation of autophagy after I/R.The activation of autophagy in I/R+HSYA group was significantly enhanced by HSYA on day 1 and day 3, and inhibited on day 7, as compared with I/R group (P<0.05).Besides, the mRNA expression of IFN-βin I/R group was significantly upregulated at 6 h, then downregulated on day 1 and day 3, and returned to basal level on day 7, as compared with sham group (P<0.05).In I/R+HSYA group, the mRNA expression of IFN-βwas significantly upregulated on day 1 and day 3, accompanied by the inhibition of apoptosis on day 3 and the significantly decreased mNSS from day 4, as compared with I/R group (P<0.05).CONCLUSION:HSYA alleviates cerebral I/R injury by dynamically modulating the activation of autophagy and the expression of IFN-βin ischemic penumbra .
ABSTRACT
AIM:To observe the Toll-like receptor 9 (TLR9) activation in microglia BV-2 cells after oxygen-glucose deprivation and reoxygenation ( OGDR) , and its effects on neuronal apoptosis.METHODS:The BV-2 cell super-natants were collected after the corresponding treatment and added to mouse primary cortical neurons after OGDR for 4 h, followed by normal culture for 24 h.The cells were divided into normal BV-2 group, NC-siRNA group, TLR9-siRNA group, OGDR group, OGDR+NC-siRNA group, OGDR+TLR9-siRNA group and control group (without adding BV-2 cell supernatant) .The changes of the neuronal morphology were observed under an inverted phase-contrast microscope, and the neuronal apoptosis was detected by TUNEL.The protein expression of cleaved caspase-3 was detected by Western blot-ting.RESULTS:After OGDR, the axon turned thin, twisted and broken, and neuronal swelling, decrease in refraction and vacuolar degeneration were observed.The green-stained apoptotic bodies in the neurons in all groups were positive. Compared with control group, the caspase-3 protein levels in other groups were increased.Compared with the normal BV-2 group, the caspase-3 protein in OGDR group and TLR9-siRNA group was increased.Compared with OGDR+TLR9-siRNA group, the caspase-3 protein in TLR9-siRNA group and OGDR group was decreased.CONCLUSION: After OGDR, TLR9 activation in BV-2 cells induces neuronal apoptosis with the increase in caspase-3 protein level.Inhibition of TLR9 expression reduces neuronal damage.