Wnt signaling in idiopathic carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most frequently reported entrapment neuropathy; however, the exact pathological mechanism of CTS remains unknown. In a recent paper published in the Journal of Orthopaedic Research, we investigated the associations between Wnt signaling and the etiology of idiopathic CTS (ICTS). We compared the expression levels of genes encoding Wnt1, 2, 3, 4, 5a, 5b, 6, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11, and 16 in the flexor tenosynovium between ICTS patients and controls, and we also evaluated whether an association exists between Wnt signaling and cell proliferation factors, such as estrogen-responsive finger protein, epidermal growth factor receptor, heparin binding-epidermal growth factor-like growth factor, insulin-like growth factor-1, and vascular endothelial growth factor (VEGF). To compare the cell proliferation potency, expression levels of MIB-1 protein were also measured. We found that Wnt9a gene expression in the flexor tenosynovium is more prominent in ICTS patients. A positive correlation was observed in only ICTS patient group for the gene expression of Wnt9a and VEGF in the flexor tenosynovium. There were no relationships between the expression levels of Wnt9a and fibroblast proliferation in either group. These results indicate that Wnt9a may be involved in the expression of VEGF in ICTS.