mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator 1α, tumor necrosis factor-α, and interleukin-6 in paraspinal muscles of patients with lumbar kyphosis: a preliminary study.

BACKGROUND

Kyphosis is a spine deformity that can lead to falls and reduced quality of life. Peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) regulates mitochondrial biogenesis and is important for proper functioning of skeletal muscle, including the paraspinal muscles, which support and allow movement of the spine. The role of PGC-1α in paraspinal muscles in lumbar kyphosis has not been examined. We also examined the expressions of the proinflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6.

METHODS

We obtained paraspinal muscle specimens from 12 patients who underwent posterior lumbar surgery. RNA was isolated from these samples, and quantitative PCR was performed to compare the expression levels of PGC-1α, TNF-α, and IL-6 mRNA between patients with decreased lumbar lordosis (LL) and normal LL patients.

RESULTS

TNF-α and IL-6 mRNA expressions in paraspinal muscles were significantly higher in the decreased LL group than in the normal LL group (P=0.048 for both). PGC-1α mRNA expression was slightly increased in the decreased LL group, but the difference was not significant. Age was significantly positively correlated with PGC-1α mRNA expression (P=0.010). PGC-1α mRNA expression was significantly positively correlated with TNF-α mRNA expression (P=0.022). LL was significantly negatively correlated with PGC-1α, TNF-α, and IL-6 mRNA expressions (P=0.015, 0.036, and 0.010, respectively).

CONCLUSION

TNF-α and IL-6 mRNA expressions in paraspinal muscles were significantly higher in the decreased LL group than in the normal LL group. LL was significantly negatively correlated with PGC-1α, TNF-α, and IL-6 mRNA expressions. PGC-1α mRNA expression levels in paraspinal muscles may be affected by lumbar kyphosis.