Integrating network pharmacology, transcriptomics to reveal neuroprotective of curcumin activate PI3K / AKT pathway in Parkinson's disease

Background: Parkinson's disease (PD), a severe threat in aging society, is a significant cause of disable. Curcumin, a polyphenol with hydrophobic properties, has been proved to against Parkinson. Our previous study provides an initial understanding of the neuroprotective mechanisms of curcumin in treating Parkinson's disease. However, further exploration in this area is needed. The present study was designed to investigate the potential mechanism of curcumin for treating PD. Methods: The therapeutic efficacy of curcumin was evaluated using behavioral tests, immunofluorescence of tyrosine hydroxylase (TH). Network pharmacology and transcriptomics predicted the active pathway and bioprocess of curcumin in PD. Activation of the PI3K / AKT signaling pathway was confirmed by quantitative real-time PCR and immunofluorescence. Result: Curcumin restored the dyskinesia and dopaminergic neurons damage of MPTP-induced mice. The results of network pharmacology and transcriptomics showed that curcumin against Parkinson's disease by regulating inflammation, oxidative stress, and aging. The mechanisms of these were associated with activation of PI3K / AKT pathway. Conclusion: In conclusion, the mechanism of curcumin against PD was revealed by our study which lays a foundation for the application of curcumin in treating. Overall design: Animals and Treatments,30 male C57BL/6J mice (8 weeks old) were obtained from Hunan Slaughter Jingda Laboratory Animal Co., Ltd. Prior to the commencement of the experiments, the mice were housed in a standard environment with unlimited access to food and water. They were kept in a pathogen-free facility for one week. The animal procedures were approved by the Ethics Committee of Hainan Hospital, Hainan Medical College. Carbon dioxide asphyxiation was used as a humane method to euthanize all the mice. The mice were then randomly divided into three groups: control, MPTP, and MPTP + Curcumin. To induce Parkinson's disease in the mouse model, MPTP (Sigma-Aldrich, United States) was administered through intraperitoneal injections at a dose of 20 mg/kg in saline, along with probenecid (250 mg/kg in tris-HCl buffer) every 3.5 days for a total of 10 doses over a period of 5 weeks. Starting from day 1 of the experiment, curcumin (Macklin, Shanghai, China) was administered daily via gavage at a dose of 60 mg/kg for 7 weeks in the MPTP + Curcumin group. Transcriptome,RNA extraction was performed using the TRIzol reagent (Invitrogen, CA, USA) as per the manufacturer's instructions. The quality and quantity of the extracted RNA were assessed using the NanoDrop 2000 spectrophotometer (Thermo Scientific, USA). The integrity of the RNA was evaluated using the Agilent 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA, USA). Subsequently, libraries were prepared using the VAHTS Universal V6 RNA-seq Library Prep Kit according to the manufacturer's protocol. The libraries were sequenced on an Illumina Novaseq 6000 platform, generating 150 bp paired-end reads. The raw reads in fastq format were processed using fastp24 to remove low quality reads, resulting in clean reads. Approximately 50 clean reads were retained for each sample for further analysis. The clean reads were then aligned to the reference genome using HISAT225. The FPKM26 of each gene was calculated and the read counts of each gene were obtained using HTSeq-count27. Principal component analysis (PCA) was performed using R (v 3.2.0) to assess the biological duplication of samples. Differential expression analysis was conducted using DESeq228, with a threshold of Q value < 0.05 and foldchange > 2 to determine significantly differentially expressed genes (DEGs). Hierarchical cluster analysis of DEGs was performed using R (v 3.2.0) to visualize the expression patterns of genes in different groups and samples. We would like to acknowledge the assistance of OE Biotech, Inc., (Shanghai, China) in sequencing and bioinformatics analysis.