Combined transcriptomics and proteomics studies on the effect of electrical stimulation on spinal cord injury in rats

Erliang Li; Rongbao Yan; Huanhuan Qiao; Jin Sun; Peng Zou; Jiaqi Chang; Shuang Li; Qiong Ma; Rui Zhang; Bo Liao

doi:10.1016/j.heliyon.2023.e23960

Combined transcriptomics and proteomics studies on the effect of electrical stimulation on spinal cord injury in rats

Heliyon. 2023 Dec 21;10(1):e23960. doi: 10.1016/j.heliyon.2023.e23960. eCollection 2024 Jan 15.

Authors

Erliang Li¹, Rongbao Yan², Huanhuan Qiao³, Jin Sun³, Peng Zou⁴, Jiaqi Chang⁵, Shuang Li³, Qiong Ma³, Rui Zhang⁴, Bo Liao³

Affiliations

¹ Department of Joint Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
² Department of Orthopaedics, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
³ Department of Orthopaedics, The Second Affiliated Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China.
⁴ Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
⁵ School of Automation Science and Electrical Engineering, Beihang University, 37th Xueyuan Road, Beijing, China.

Abstract

Electrical stimulation (ES) of the spinal cord is a promising therapy for functional rehabilitation after spinal cord injury (SCI). However, the specific mechanism of action is poorly understood. We designed and applied an implanted ES device in the SCI area in rats and determined the effect of ES on the treatment of motor dysfunction after SCI using behavioral scores. Additionally, we examined the molecular characteristics of the samples using proteomic and transcriptomic sequencing. The differential molecules between groups were identified using statistical analyses. Molecular, network, and pathway-based analyses were used to identify group-specific biological features. ES (0.5 mA, 0.1 ms, 50 Hz) had a positive effect on motor dysfunction and neuronal regeneration in rats after SCI. Six samples (three independent replicates in each group) were used for transcriptome sequencing; we obtained 1026 differential genes, comprising 274 upregulated genes and 752 downregulated genes. A total of 10 samples were obtained: four samples in the ES group and six samples in the SCI group; for the proteome sequencing, 48 differential proteins were identified, including 45 up-regulated and three down-regulated proteins. Combined transcriptomic and proteomic studies have shown that the main enrichment pathway is the hedgehog signaling pathway. Western blot results showed that the expression levels of Sonic hedgehog (SHH) (P < 0.001), Smoothened (SMO) (P = 0.0338), and GLI-1 (P < 0.01) proteins in the ES treatment group were significantly higher than those in the SCI group. The immunofluorescence results showed significantly increased expression of SHH (P = 0.0181), SMO (P = 0.021), and GLI-1 (P = 0.0126) in the ES group compared with that in the SCI group. In conclusion, ES after SCI had a positive effect on motor dysfunction and anti-inflammatory effects in rats. Moreover, transcriptomic and proteomic sequencing also provided unique perspectives on the complex relationships between ES on SCI, where the SHH signaling pathway plays a critical role. Our study provides a significant theoretical foundation for the clinical implementation of ES therapy in patients with SCI.

Keywords: Electrical stimulation; Proteomics; Sonic hedgehog signal pathway; Spinal cord injury; Transcriptomics.