Genome-Wide Expression Profiling by RNA-Sequencing in Spinal Cord Dorsal Horn of a Rat Chronic Postsurgical Pain Model to Explore Potential Mechanisms Involved in Chronic Pain

Ruoyao Xu,1 Jie Wang,1 Huimin Nie,1 Danyi Zeng,1 Chengyu Yin,1 Yuanyuan Li,1 Huina Wei,1 Boyu Liu,1 Yan Tai,2 Qimiao Hu,1 Xiaomei Shao,1 Jianqiao Fang,1 Boyi Liu1 1Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Hangzhou, 310053, People’s Republic of China; 2Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, People’s Republic of ChinaCorrespondence: Boyi Liu; Jianqiao Fang, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Hangzhou, 310053, People’s Republic of China, Email boyi.liu@foxmail.com; fangjianqiao7532@163.comBackground: Chronic postsurgical pain (CPSP) is common among patients receiving major surgeries. CPSP produces suffering in patients, both physically and mentally. However, the mechanisms underlying CPSP remain elusive. Here, a genome-wide expression profiling of ipsilateral spinal cord dorsal horn (SCDH) was performed to identify potential genes related with CPSP.Methods: A rat skin/muscle incision and retraction (SMIR) model was established to induce CPSP. Immunostaining was used to study glial cell and neuron activation in ipsilateral SCDH of SMIR model rats. RNA sequencing (RNA-Seq), combined with bioinformatics analysis, was undertaken to explore gene expression profiles. qPCR was applied to validate the expression of some representative genes.Results: The SMIR model rats developed persistent mechanical allodynia in ipsilateral hindpaw for up to 14 days. Ipsilateral SCDH of SMIR rats showed remarkable glial cell and neuron activation. A number of differentially expressed genes (DEGs) were identified in ipsilateral SCDH of SMIR rats by RNA-Seq. qPCR confirmed expression of some representative DEGs. Bioinformatics indicated that chemical synaptic transmission, sensory perception of pain and neuroactive ligand-receptor interaction were predominant functions. We compared our dataset with human pain-related genes and found that several genes exclusively participate in pain modulation and mechanisms.Conclusion: Our study provided novel understandings of the molecular mechanisms possibly contributing to CPSP. These findings may offer new targets for future treatment of CPSP.Keywords: postsurgical pain, spinal cord dorsal horn, RNA-Seq, microglia, genome