Calcium gluconate alleviates the toxic effect of hydrofluoric acid on human dermal fibroblasts through the Wnt/β-catenin pathway

The present study was performed to determine the molecular mechanism of calcium gluconate (CG) in alleviating the toxic effect of hydrofluoric (HF) acid on human dermal fibroblasts (HDFs). HDF morphology was observed by optical microscopy and the vimentin immunofluorescence assay. Cell viability and apoptosis were evaluated by the Cell Counting Kit-8 and Annexin V/propidium iodide assays, respectively. The levels of apoptosis-associated factors, as well as Wnt2, Wnt3a and β-catenin were detected by reverse transcription-quantitative polymerase chain reaction and western blotting. Levels of matrix metalloproteinase (MMP)-1 and basic fibroblast growth factor (bFGF) were detected by ELISA and western blotting. Carboxyterminal propeptide of type I collagen (CICP) was detected by ELISA, while L-Hydroxyproline (L-HYP) was detected by colorimetry. First, the morphology of normal HDFs was observed. Cell viability was inhibited and apoptosis was increased in a dose- and time-dependent manner following treatment with HF acid [0, 2, 4, 6, 8, 10 and 20% (v/v)] for 0, 2, 4, 6, 8, 10 and 20 min. The effects were blocked by CG at different doses (50, 100 and 200 µmol/l) and time points (6, 12 and 24 h), following treatment with 8% (v/v) HF acid for 6 min. The levels of Caspase-3, B-cell lymphoma (Bcl)-2 associated X protein, Wnt2, Wnt3a and β-catenin were decreased, whereas Bcl-2 was increased by CG treatment dose-dependently, when compared with HF control. CG promoted the expression of MMP-1, bFGF and L-HYP, and inhibited CICP, when compared with HF control. Based on the present results, CG alleviated the toxic effect of HF acid on HDFs by regulating the Wnt/β-catenin signaling pathway.