Changes in the Expression Profile of Growth-Associated Protein 43 in Degenerative Lumbosacral Stenosis

<b>Background:</b> Degenerative spinal stenosis is a common condition associated with structural degeneration and pain, yet its molecular underpinnings remain incompletely understood. Growth-associated protein 43 (GAP-43), a key player in neuronal plasticity and regeneration, may serve as a biomarker for disease progression and pain severity. This study investigates the expression of GAP-43 at the mRNA and protein levels in the ligamentum flavum of affected patients. <b>Methods:</b> Samples were collected from 96 patients with degenerative spinal stenosis and 85 controls. <i>GAP-43</i> mRNA expression was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), while protein levels were quantified via enzyme-linked immunosorbent assay (ELISA) and Western blot. Pain severity was assessed using the visual analog scale (VAS), and associations with lifestyle factors were analyzed. <b>Results:</b><i>GAP-43</i> mRNA expression was significantly downregulated in the study group compared to the controls (fold change = 0.58 ± 0.12, <i>p</i> < 0.05), with an inverse correlation to VAS pain severity (fold change = 0.76 at VAS 4 vs. 0.36 at VAS 10). Conversely, GAP-43 protein levels were markedly elevated in the study group (5.57 ± 0.21 ng/mL) when compared to controls (0.54 ± 0.87 ng/mL, <i>p</i> < 0.0001). Protein levels were also correlated with lifestyle factors, including smoking and alcohol consumption (<i>p</i> < 0.05). <b>Conclusions:</b> GAP-43 shows potential as a biomarker for pain severity and disease progression in degenerative spinal stenosis, in a manner influenced by lifestyle factors. Further research is needed to explore its diagnostic and therapeutic applications.