Effects of Naotai Formula(脑泰方)on Cerebral White Matter Lesions and Wnt/β-Catenin Pathway in Corpus Callosum of Rats with Cerebral Small Vessel Disease Model
Objective To explore the effects and mechanisms of Naotai Formula(脑泰方)against white matter lesions associated with cerebrovascular disease via Wnt/β-catenin pathway.Methods Ten WKY rats were used as sham surgery group,and 30 spontaneously hypertensive rats(SHRs)were randomly divided into model group,low-and high-dose Naotai Formula group,with 10 rats in each group.In addition to the sham surgery group,rats in each group were modelled by dorsum subcutaneous injection of D-galactose for 56 days,by performing bilateral common carotid artery stenosis on the 29th day of modelling with low perfusion for 28 days to construct the rat models of cere-bral small-vessel disease with composite risk factors.The rats in the low-and high-dose Naotai Formula groups were given 9 and 27 g/(kg·d)of Naotai Formula by gavage on the day after surgery,and 10 ml/(kg·d)of pure water by ga-vage in the sham surgery group and the model group,with all rats in each group gavaged for 4 weeks.Blood pressure of rats was monitored weekly before and after medication administration;water maze experiments were performed for 6 consecutive days from the 50th day of modelling;and changes in cerebral blood flow were detected by laser scattering preoperatively,postoperatively,and after medication administration.The samples were taken on the next day after the last gavage,and the extent of myelin damage in the rat corpus callosum was observed by Lucas fast blue(LFB)and transmission electron microscopy,and the levels of interleukin 1β(IL-1β),tumour necrosis factor α(TNF-α),interleukin 10(IL-10),and tumour necrosis factor β(TNF-β)were detected by ELISA,and the levels of expression of myelin basic protein(MBP)and ionized calcium binding adaptor molecule 1(IBA1),neuroglial antigen 2(NG2),cell proliferation marker Ki67 antigen(MBP),and cell proliferation marker Ki67 antigen(Ki67A)/NG2,2',3'-cyclic-nucleotide 3'-phosphodiesterase(CNPase)expression were measured by immunofluorescence.MBP in the corpus callosum,wingless MMTV integration site family member 3a(Wnt3a),phosphorylated glycogen synthase kinase 3β(p-GSK-3β),glycogen synthase kinase 3β(GSK-3β),phosphorylated β-catenin(p-β-catenin),β-catenin expression were detected by western blotting,and GSK-3β,β-catenin mRNA expression in the corpus callosum were detected by RT-qPCR.Results Compared with the sham surgery group,rats in the model group had elevated systolic blood pressure at all time points,decreased the number of traversing platforms and the percentage of time spent in the target quadrant in the water maze experiments,significantly prolonged the evasion latency on days 4 and 5,and decreased cerebral blood flow in the postoperative period and after medication administration(P＜0.05 or P＜0.01);signifi-cant myelin sheath damage in the corpus callosum was seen by LFB staining and transmission electron microscopy;the callus had significantly higher levels of TNF-α and IL-1β content increased,TNF-β content decreased,MBP fluo-rescence intensity and protein expression decreased,the number of IBA1-positive cells increased,Wnt3a and p-GSK-3β/GSK-3β values increased,p-β-catenin/β-catenin values decreased,GSK-3β mRNA expression decreased,andβ-catenin mRNA expression increased(P＜0.05 or P＜0.01).Compared with the model group,the myelin sheath damage of corpus callosum in rats in the high-dose Naotai Formula groups was significantly improved,and all of the above indexes were significantly improved(P＜0.05 or P＜0.01).Compared with the low-dose Naotai Formula group,myelin damage in the corpus callosum of the high-dose Naotai Formula group was improved,systolic blood pressure reduced,cerebral blood flow and MBP fluorescence intensity and protein expression in the corpus callosum,the number of positive cells for NG2 and CNPase,the values of p-β-catenin/β-catenin and GSK-3β mRNA expression increased,and the expression of Wnt3a,p-GSK-3β/GSK-3β values and β-catenin mRNA expression decreased(P＜0.05 or P＜0.01).Conclusions High-dose Naotai Formula can significantly improve white matter lesions in cerebral small vessel disease,and the mechanism may be related to the inhibition of the Wnt/β-catenin signalling pathway,reducing the inflammatory microenvironment in the brain,and promoting the differentiation of oligodendrocyte precursor cells into oligodendrocytes.
cerebral small vessel diseasewhite matter lesiondemyelinationoligodendrocyteNaotai Formula(脑泰方)Wnt/β-catenin pathway
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