Extracellular calcium-sensing receptor mediates human bronchial epithelial wound repair.
The airway epithelium routinely undergoes damage that requires repair to restore epithelial barrier integrity. Cell migration followed by proliferation are necessary steps to achieve epithelial repair. Calcium-sensing receptor (CaSR) is implicated in cell migration and proliferation processes. Thus we hypothesized that CaSR mediates lung epithelial wound repair. We detected CaSR expression in human lung and in well-differentiated human bronchial epithelial cells (HBEC). To test the CaSR functionality, HBEC loaded with fura-2 were stimulated with extracellular Ca(2+) ([Ca(2+)](out)) which resulted in a concentration-dependent intracellular Ca(2+) ([Ca(2+)](i)) increase (potency approximately 5.6mM [Ca(2+)](out)). Furthermore, increasing [Ca(2+)](out) induced phosphorylation of the extracellular signal-regulated kinase (ERK1/2) which was blocked by siRNA-CaSR and the specific inhibitor of CaSR, NPS2390. Epithelial repair after mechanical injury of differentiated HBEC was a process dependent of [Ca(2+)](out) since it accelerated wound repair and HBEC proliferation being highest at 5mM [Ca(2+)](out). Furthermore, U73122 (an inhibitor of phospholipase C (PLC)) and PD 98059 (an inhibitor of ERK1/2) as well as siRNA-CaSR and NPS2390 partially inhibited wound repair and HBEC proliferation. On the other hand, mechanical injury produced an [Ca(2+)](i) wave propagation that was partially inhibited by siRNA-CaSR, NPS2390 and the extracellular Ca(2+) chelator EGTA, which suggest a link of CaSR between cell-cell communication and wound repair in differentiated HBEC. Our data, for the first time, shows that CaSR plays an important role in airway epithelial repair, which may help to develop novel regenerative therapeutics allowing the rapid repair of lung damaged epithelium.
Milara
Javier
J
University General Hospital Consortium, Valencia, Spain. xmilara@hotmail.com <xmilara@hotmail.com>
Mata
Manuel
M
Serrano
Adela
A
Peiró
Teresa
T
Morcillo
Esteban J
EJ
Cortijo
Julio
J
D001980:Bronchi / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004533:Egtazic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D004963:Estrenes / Q000494:pharmacology; D016257:Fura-2 / Q000494:pharmacology; D006801:Humans; D011760:Pyrrolidinones / Q000494:pharmacology; D044169:Receptors, Calcium-Sensing / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*
D004791:Enzyme Inhibitors; D004963:Estrenes; D011760:Pyrrolidinones; D044169:Receptors, Calcium-Sensing; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D004533:Egtazic Acid; D002118:Calcium; D016257:Fura-2