Mechanism of astragaloside IV regulating NLRP3 through LOC102555978 to attenuate cerebral ischemia reperfusion induced microglia pyroptosis.

Astragaloside IV(ASⅣ), the main component of Radix Astragali, has been used to treat cerebral ischemia reperfusion injury (CIRI). However, the molecular mechanism of ASIV in CIRI needs to be further elucidated. Long non-coding RNA (lncRNA) is considered to be an important kind of regulatory molecule in CIRI. In this work, the biological effect and molecular mechanism of ASIV in CIRI through lncRNA were analyzed by using rat middle cerebral artery occlusion and reperfusion (MCAO/R) model and primary rat microglia (RM) cells oxygen and glucose deprivation/reoxygenation (OGD/R) model. The neurological deficit score was evaluated, the volume of cerebral infarction was calculated, and pyroptosis related molecules were detected by qPCR and western blot. Then, high-throughput sequencing was performed in sham and MCAO/R groups. The competitive endogenous RNA (ceRNA) networks associated with pyroptosis were constructed by functional enrichment analysis. CCK-8 detection of cell survival rate, qPCR and western blot were used to determine the specific molecular mechanism of ASⅣ through ceRNA in vitro. Results showed thatASⅣ could decrease the neurological deficit score, reduce the volume of cerebral infarction, inhibit inflammatory reaction and pyroptosis in MCAO/R model rats. Next, the ceRNA network was established, including the LOC102555978/miR-3584-5p/NLRP3 regulatory network. In vitro experiments showed that LOC102555978 promotes NLRP3 mediated pyroptosis of RM cells through sponge adsorption of miR-3584-5p, which may provide a potential therapeutic target for post-CIRI inflammation regulation. ASⅣ could inhibit pyroptosis of RM cells by down-regulating LOC102555978. LOC102555978/miR-3584-5p/NLRP3 may be the molecular mechanism of ASⅣ's CIRI protective effect.

PF4 induces inflammatory response through NF-kB signal pathway in rats with intracerebral haemorrhage.

Intracerebral haemorrhage (ICH) is a lethal cerebrovascular disorder with a high mortality and morbidity. Although it is a major public health problem, there is no effective treatment for ICH. After ICH, the primary and secondary mechanisms are mentioned when discussing brain injury. The transcription factor, nuclear factor-kappa B (NF-kB), is an important regulator of inflammatory responses. The role of platelet factor 4 (PF4) in ICH is unclear. To study the effect of PF4 on inflammatory response of rats in ICH, a rat model of striatum ICH was established by injecting autologous blood from the autogenous femoral artery into the right striatum of rats. Forty-eight hours after ICH, the expression of PF4, NF-kB (P-P65) and inflammatory changes in rats were determined with WB and ELISA. Heme was used to induce PC12 cell damage, simulate the ICH model in vitro, and detect PF4, P-P65 and striatal inflammatory changes. Short hairpin RNA (shRNA-PF4) was used to knock-down the expression of PF4 in PC12 cells to detect changes in inflammatory factors. The results showed that 48 hours after surgery, the behavioural score of cerebral haemorrhage was the lowest. The expression of PF4 and P-P65 in the striatum of the ICH group was significantly higher compared with the sham surgery group. The expression of interleukin (IL)-6 and IL-1b in the ICH group was also greatly improved. After inhibiting NF-kB expression, PF4 expression was decreased. In short, ICH enhances the expression of PF4, which induces an inflammatory response in rats with cerebral haemorrhage through the NF-kB signalling pathway. Reducing the expression of PF4 can attenuate the inflammatory response.