[Effect of ultrasound-guided foraminal electroacupuncture on spinal cord injury based on the Wnt/β-catenin signaling pathway].

Objective: To observe the effects of ultrasound-guided foraminal electroacupuncture on neuronal apoptosis and motor function in rats with spinal cord injury (SCI), and to explore the potential underlying mechanisms.

Methods: Thirty-six SPF-grade Sprague-Dawley rats were randomly assigned to a sham operation group, a model group, and an ultrasound-guilded electroacupuncture group (electroacupuncture group), with 12 rats in each group. In the sham operation group, the spinal cord was exposed and then the incision was sutured without contusion. In the other two groups, SCI models were established using a modified Allen's impact method. On days 1, 3, 7, and 14 after modeling, the electroacupuncture group received electroacupuncture intervention at the T₉/T₁₀ and T₁₀/T₁₁ intervertebral foramen under ultrasound guidance, avoiding spinal cord injury. Stimulation parameters were dense-disperse wave at 2 Hz/100 Hz and 1-2 mA for each session. Following interventions on days 1, 3, 7, and 14, the Basso-Beattie-Bresnahan (BBB) score was assessed; the inclined plane test was used to assess hindlimb grip strength in rats. After the intervention, HE staining was used to observe spinal cord morphology; TUNEL staining was used to detect neuronal apoptosis; ELISA was used to measure the serum levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α); Western blot was used to analyze the protein expression of Wnt-4, β-catenin, c-Myc, Bax, Bcl-2, and NeuN in spinal tissue; quantitative real-time PCR was used to detect the mRNA expression of Wnt-4, β-catenin, c-Myc, Bax, Bcl-2, and NeuN.

Results: Compared with the sham operation group, the model group showed significantly reduced BBB scores (P<0.05), and reduced inclined plane angles (P<0.05) at all time points. Compared with the model group, the electroacupuncture group exhibited increased BBB scores on days 3, 7, and 14 (P<0.05), and higher inclined plane angles on days 1, 3, 7, and 14 (P<0.05). Compared with the sham operation group, the model group showed disorganized spinal cord structure with increased inflammatory cells and necrotic neurons, higher number of apoptotic neurons in spinal tissue (P<0.05), elevated serum IL-6, IL-1β, and TNF-α levels (P<0.05), increased protein and mRNA expression of Wnt-4, β-catenin, c-Myc, and Bax (P<0.05), and decreased protein and mRNA expression of Bcl-2 and NeuN in spinal tissue (P<0.05). Compared with the model group, the electroacupuncture group had fewer inflammatory cells and apoptotic neurons in spinal tissue (P<0.05), reduced serum IL-6, IL-1β, and TNF-α levels (P<0.05), increased protein and mRNA expression of Wnt-4, β-catenin, Bcl-2, and NeuN (P<0.05), and decreased protein and mRNA expression of c-Myc and Bax in spinal tissue (P<0.05).

Conclusion: Ultrasound-guided foraminal electroacupuncture could improve motor function in rats with SCI, potentially by regulating the expression of molecules related to the Wnt-4/β-catenin signaling pathway to inhibit neuronal apoptosis and inflammatory responses.