Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA(1)-LPA(6)) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA(1) inhibited the cell motile activities of mouse fibroblast 313 cells. In the present study, to evaluate a role of LPA(5) in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA(1) and LPA(5) on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA(5) may act as a negative regulator of cellular responses in mouse fibroblast 313 cells, similar to the case for LPA(1). (C) 2014 Elsevier Inc. All rights reserved.