Pseudarthrosis of cervical rib: an unusual cause of thoracic outlet syndrome

Thoracic outlet syndrome is uncommon in adolescence. Cervical rib fracture is an extremely rare cause of thoracic outlet syndrome in this age group. We report an unusual case of thoracic outlet syndrome in a 14-year-old girl caused by pseudarthrosis of the cervical rib. A magnetic resonance imaging scan showed significant compression of the brachial plexus by the pseudarthrosis mass. Excision of the cervical rib through a supraclavicular approach gave excellent results in this case.     

Keloid fibroblasts are more sensitive to Wnt3a treatment in terms of elevated cellular growth and fibronectin expression

Background

Current evidence suggests the potential role of Wnt signalling in keloids pathogenesis but such literature remains scanty. We hypothesize that Wnt signalling is upregulated in keloid fibroblasts (KFs) and this promotes cellular growth, migration and extracellular matrix (ECM) production in such fibroblasts.

Objectives

To verify the downregulation of secreted frizzled-related protein 1 (SFRP1), a Wnt inhibitor and test KFs sensitivity to Wnt3a treatment compared to NFs in terms of activation of Wnt/β-catenin, cellular growth, migration and ECM expressions. Next, to investigate if ectopic expression of SFRP1 and treatment of quercetin in KFs can reverse their phenotypes.

Methods

Quantitative Real-time PCR and western blotting were used to verify SFRP1 expression in NFs and KFs. The fibroblasts were tested with Wnt3a conditioned media and its effects were tested for (1) the cells’ sensitivity to direct Wnt signalling via the activation of TCF reporter assay and protein expression of β-catenin, (2) cellular growth, (3) cell migration and (4) expressions of ECM components. Finally KFs were stably transduced with SFRP1 and treated with 2 doses of quercetin.

Results

Lower levels of SFRP1 were confirmed at mRNA and protein levels in KFs which partly explained their sensitivity to Wnt3a treatment in terms of higher Wnt activation, cellular growth and fibronectin expression. Interestingly, Wnt3a did not promote higher cell migration rate and increase in collagen I expression. Ectopic expression of SFRP1 and quercetin treatment was able to mitigate Wnt3a-mediated phenotype of KFs.

Conclusions

Using SFRP1 or inhibitors of Wnt signalling might be one of the therapeutic solutions to treat keloid scarring.