Dental pulp fibroblasts contain target cells for lysophosphatidic Acid.
Lysophosphatidic acid (LPA) is a locally produced bioactive phospholipid which is involved in tissue repair. The objective of this study was to determine whether dental pulp tissue also responds to the phospholipid. Effects of LPA on proliferation, differentiation, and mitogen-activated protein kinase (MAPK) signaling of dental pulp fibroblasts (DPF) were examined in vitro. We report that DPF express LPA receptors LPA1, LPA2, and LPA3 and respond to the ligand with increased mitogenic activity. Involvement of extracellular signal-regulated kinase, p38 MAPK, and c-Jun NH(2)-terminal kinase in LPA signaling could be demonstrated by use of specific inhibitors and detection of the phosphorylation status of the kinases. An increased mitogenic activity paralleled a decreased number of alkaline-phosphatase-positive cells and expression levels of dentin sialophosphoprotein and osteocalcin. Together, these results suggest that dental pulp fibroblasts can respond to LPA, a process that may play a role in pulp tissue repair.
Gruber
R
R
Department of Oral Surgery, Vienna Medical University, Waehringerstrasse 25a, A-1090 Vienna, Austria. reinhardt.gruber@akh-wien.ac.at
Kandler
B
B
Jindra
C
C
Watzak
G
G
Watzek
G
G
D000328:Adult; D000469:Alkaline Phosphatase / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects*; D016326:Extracellular Matrix Proteins; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D008246:Lysophospholipids / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000032:analysis; D015675:Osteocalcin / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation; D011498:Protein Precursors / Q000032:analysis; D043562:Receptors, G-Protein-Coupled / Q000032:analysis; D049368:Receptors, Lysophosphatidic Acid; D012795:Sialoglycoproteins / Q000032:analysis; D048051:p38 Mitogen-Activated Protein Kinases; D000099311:Dentin Sialophosphoprotein
D000469:Alkaline Phosphatase; D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D008246:Lysophospholipids; D020928:Mitogen-Activated Protein Kinases; D015675:Osteocalcin; D010750:Phosphoproteins; D011498:Protein Precursors; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D012795:Sialoglycoproteins; D048051:p38 Mitogen-Activated Protein Kinases; D000099311:Dentin Sialophosphoprotein; C032881:lysophosphatidic acid