Laminin alpha 1 as a target for the treatment of epidural fibrosis by regulating fibrotic mechanisms

Excessive proliferation and migration of fibroblasts in the lumbar laminectomy area can lead to epidural fibrosis, eventually resulting in failed back surgery syndrome. It has been reported that laminin alpha 1, a significant biofunctional glycoprotein in the extracellular matrix, is involved in several fibrosis-related diseases, such as pulmonary, liver and keloid fibrosis. However, the underlying mechanism of laminin alpha 1 in epidural fibrosis remains unknown. The present study aimed to explore the effect and mechanism of laminin alpha 1 in fibroblast proliferation, apoptosis and migration, and epidural fibrosis. Following the establishment of a laminectomy model, hematoxylin and eosin, Masson's trichrome and immunohistochemical staining were performed to determine the degree of epidural fibrosis, the number of fibroblasts, collagen content and the epidural expression levels of laminin alpha 1, respectively. Furthermore, a stable small interfering RNA system was used to knock down the expression of laminin alpha 1 in fibroblasts. The transfection efficiency was confirmed by reverse transcription-quantitative PCR and immunofluorescence staining. Western blot analysis, scratch wound assay, EdU incorporation assay, flow cytometric analysis and Cell Counting Kit 8 assay were performed to assess the proliferation, apoptosis, migration and viability of fibroblasts, as well as the expression levels of the AKT/mechanistic target of rapamycin (mTOR) signaling-related proteins. In vivo experiments revealed that laminin alpha 1 was positively and time-dependently associated with epidural fibrosis. In addition, laminin alpha 1 knockdown attenuated cell proliferation, viability and migration, and promoted apoptosis. Furthermore, the results revealed that the activation of the AKT/mTOR signaling pathway was involved in the aforementioned processes. Overall, the current study illustrated the positive association between laminin alpha 1 and epidural fibrosis, and also verified the effect of laminin alpha 1 on fibroblast proliferation, apoptosis and migration. Furthermore, the results suggested that the AKT/mTOR signaling pathway may serve a significant role in regulating the behavior of laminin alpha 1-induced fibroblasts.