Estrogen Receptor Type 1 and Type 2 Presence in Paravertebral Skeletal Muscles: Expression Level and Relation to Phenotype in Children with Idiopathic Scoliosis.

The study aimed to detect the presence and assess the expression levels of the estrogen receptors type 1 (ESR1) and type 2 (ESR2) within paravertebral skeletal muscles of female patients with idiopathic scoliosis (IS) in relation to phenotype parameters. Intraoperatively, the muscle samples were obtained from 35 adolescent females. The RT-qPCR, western blot and immunohistochemistry techniques were applied. The ESR1 and ESR2 were detected within paravertebral skeletal muscle cells, either the superficial or the deep ones. The ESR1 expression level was significantly higher in the deep muscles compared to the superficial ones. A left-right asymmetry of the ESR1 and ESR2 expression level was demonstrated in the deep muscles. There was a significant relationship between the expression asymmetry and either the Cobb angle or the progression risk factor: both parameters decreased to the smallest values in the case of symmetric ESR1 or ESR2 expression, while they increased with increasing expression asymmetry. In conclusion, the ESR1 and ESR2 presence was confirmed in skeletal paravertebral muscles of patients with idiopathic scoliosis. The increased expression level and asymmetry of estrogen receptors in deep skeletal muscles was related to increasing scoliotic deformity magnitude or increasing risk of deformity deterioration. These findings may highlight the etiopathogenesis of IS in children.

Estrogen receptor 2 expression in back muscles of girls with idiopathic scoliosis - relation to radiological parameters.

Deep paravertebral muscles and female sex hormones are potential elements participating in idiopathic scoliosis development. Estrogen acts through estrogen receptors: ESR1 and ESR2. There are no studies describing ESR2 expression in back muscles in girls with idiopathic scoliosis. The aim of this study was to evaluate ESR2 expression levels in back muscles on both sides of the spinal curve and correlation between the expression level and scoliosis parameters. Asymmetrical ESR2 expression in deep paravertebral muscles was found: 11 girls had higher expression level on the convex side and 5 girls had higher expression level on the concave side of the curvature. Patients with ESR2 (convex/concave) ratio ≥ 1 presented positive correlation between ESR2 ratio and Cobb angle.