Negative pressure induces p120-catenin-dependent adherens junction disassembly in keratinocytes during wound healing.

Abstract A negative-pressure of 125 mm Hg (NP) has been widely used to treat chronic wounds in modern medicine. Keratinocytes under NP treatment have shown accelerated cell movement and decreased E-cadherin expression. However, the molecular mechanism of E-cadherin regulation under NP remains incompletely understood. Therefore, we investigated the E-cadherin regulation in keratinocytes (HaCaT cells) under NP. HaCaT cells were treated at ambient pressure (AP) and NP for 12 h. Cell movement was measured by traditional and electric wound healing assays at the 2 different pressures. Mutants with overexpression of p120-catenin (p120 ctn ) were used to observe the effect of NP on p120 ctn and E-cadherin expression during wound healing. Cell fractionation and immunoblotting data showed that NP increased Y228-phosphorylated p120 ctn level and resulted in the translocation of p120 ctn from the plasma membrane to cytoplasm. Immunofluorescence images revealed that NP decreased the co-localization of p120 ctn and E-cadherin on the plasma membrane. Knockdown of p120 ctn reduced E-cadherin expression and accelerated cell movement under AP. Overexpression of the Y228-phosphorylation-mimic p120 ctn decreased E-cadherin membrane expression under both AP and NP. Phosphorylation-deficient mutants conferred restored adherens junctions (AJs) under NP. The Src inhibitor blocked the phosphorylation of p120 ctn and impeded cell migration under NP. In conclusion, Src-dependent phosphorylation of p120 ctn can respond rapidly to NP and contribute to E-cadherin downregulation. The NP-induced disassembly of the AJ further accelerates wound healing.