ABSTRACT: Peripheral compressive neuropathy results in significant neuropathic pain, muscle weakness, and prolonged neuroinflammation. Surgical decompression remains the gold standard for treatment; however, the outcomes are often suboptimal, and patients have a high recurrence rate. In this study, we employed a reproducible and controllable chronic constriction injury (CCI) rat model to simulate early nerve decompression. The rat sciatic nerve was constricted for a short duration, followed by release, which induced reversible sensorimotor dysfunction. We further explored the genes involved in nerve regeneration via NanoString analysis. Compared with the control nerves, the differentially expressed genes (DEGs) Mmp12, Il1rn, Fcgr3, Hmox1, Lst1, Ccl2, Nlrp3, Il2rg, and Sell were downregulated in the constricted nerves at days 7 and 14 after release. Other significant DEGs, such as Gsn, Ugt8a, Snca, Slc6a1, Pmp22, Kdm5d, Mal, Plp1, Slc2a1, Gjb1, Cyp27a1, and Plekhb1, were upregulated on days 7 and 14. When the correlations between these upregulated DEGs and nerve regeneration were investigated, we found that Slc6a1, also known as GABA transporter 1 (Gat1), was associated with nerve regeneration. To further understand its role, we overexpressed Gat1 in a rat neuronal Schwann cell line, RT4-D6P2T. This led to increased viability of the Gat1-overexpressing cells. Additionally, neuronal markers including Nefh, S100b, and Ngfr, along with cell proliferation signaling molecules, such as p-Akt and p-Mapk, were elevated in these cells. The increase in viability and neuronal marker expression was inhibited by the Gat1 inhibitor tiagabine in Gat1-overexpressing cells. To simulate neuronal damage and recovery, we treated the cells with H2O2 for 2 hours and then allowed them to recover in growth medium for 1 and 7 days. The data indicated that the mRNA and protein levels of Gat1 were reduced on day 1 but upregulated by day 7. Consistently, the decrease in the expression of neuronal markers observed on day 1 was reversed by day 7. Taken together, our findings demonstrate that Gat1 plays a significant role in neuronal regeneration in both a cell model and an animal model of CCI.
