Expression of HSPA8 in Nucleus Pulposus of Lumbar Intervertebral Disc and Its Effect on Degree of Degeneration

Introduction This study aimed to investigate the expression of a 70-kDa heat shock protein [heat shock 70-kDa protein 8 (HSPA8)/heat shock protein 70 (Hsc70)] in human degenerative lumbar intervertebral discs and its relationship with the degree of degeneration of human intervertebral discs. Methods A total of 72 cases of lumbar intervertebral disc nucleus pulposus tissues were collected. Among these, 18 cases of nucleus pulposus tissue were assigned to the control group, while 54 cases of nucleus pulposus tissues were assigned to the experimental group. According to the preoperative MRI, cases in the experimental group were further divided into three groups: protrusion group ( n = 18), extrusion group ( n = 18), and sequestration group ( n = 18). Western blot was performed to determine the relative expression of HSPA8 in the nucleus pulposus in each group. Hematoxylin and eosin staining was performed to determine the number of nucleus pulposus cells, morphological differences, and cell densities of the degenerated intervertebral discs and normal intervertebral discs. Immunohistochemistry was performed to determine the expression of HSPA8 in nucleus pulposus tissues in each group. Results Hematoxylin and eosin staining results: There were significant differences in cell morphology and number between the control group and the experimental group. Furthermore, there were significant differences in cell density ( F = 936.80, P < 0.01). Immunohistochemistry results: HSPA8 was expressed in lumbar intervertebral disc nucleus pulposus tissues, and its expression of gradually decreased with the severity of the disease, and the differences were significant ( F = 2110.43, P < 0.01). Western blot results: The expression of HSPA8 in human degenerative nucleus pulposus tissues gradually decreased, and the differences were significant ( F = 1841.72, P < 0.01). Conclusion HSPA8 is stably expressed in human intervertebral disc nucleus pulposus tissues, and its expression is associated with the degree of intervertebral disc degeneration.