Exosomal miRNA-222 Alerts shRNA-PCSK9 Induction Brain Tau Hyperphosphorylation
OBJECTIVE To investigate whether the microRNA-222(miRNA-222)carried by plasma exosomes can serve as an early warning marker for cognitive impairment induced by shRNA-PCSK9.METHODS The high-fat diet(HFD)was used to prepare a hypercholesterolemic mouse model group.The model group mice were divided into HFD-shRNA control group and HFD-shRNA-PCSK9 group.The shRNA-PCSK9 was constructed,injected intravenously into the body,and the expression of PCSK9 mRNA was detected by real-time PCR(RT-PCR).Tau protein and phosphorylation in brain tissue were observed by immunohistochemistry(IHC).Western blotting was used to detect Tau protein and P-Tau protein.Serum amyloid Aβ1-42Ab levels were determined by ELISA.The kits extracted plasma exosomes step by step,identify the exosome morphology by negative staining electron microscopy,and determined the size of exosomes by NTA technology.RT-PCR technique was used to detect the expression level of miRNA-222 carried in plasma exosomes.RESULTS The model mouse were prepared by feeding HFD for 13 weeks,whose total cholesterol(TC)and low-density lipoprotein(LDL-C)contents in serum were significantly increased.At the same time,the expression of PCSK9 mRNA in the brain tissue of model group was significantly increased.After shRNA-PCSK9 lentivirus interference,PCSK9 mRNA expression was inhibited,and IHC observed that shRNA-PCSK9 induced abnormal expression and hyperphosphorylation of Tau protein in brain tissue,indicating that the pathological changes of neurofibrillary tangles had occurred.However,at this time,serum Aβ1-42Ab had not been significantly increased,and it had not yet been of significance for the diagnosis of cognitive impairment.The miRNA in plasma exosomes was extracted,and RT-PCR results showed that the expression of miRNA-222 carried in the exosomes of the HFD-shRNA-PCSK9 group was significantly lower than that of the HFD-shRNA control group.CONCLUSION Plasma exosomes carried miRNA-222 provides an early warning marker for shRNA-PCSK9-induced cognitive impairment.
万方数据
维普
