Differential anatomical and cellular expression of lysophosphatidic acid receptor 1 in adult mouse brain.

Lysophosphatidic acid (LPA) is a bioactive phospholipid that acts as an extracellular signaling molecule through six G-protein-coupled receptors: LPA-LPA. Recent studies have demonstrated that LPA signaling via LPA receptor plays a crucial role in cognition and emotion. However, because of limited availability of reliable antibodies, it is currently difficult to identify the cell types expressing LPA receptor in the brain. The current study explored the cellular distribution pattern of LPA receptor in the brain using the LPA lacZ-knock-in reporter mice. In situ hybridization and immunohistochemistry revealed that LacZ gene expression in these mice reflected the expression of endogenous LPA receptor in the brain. Overall, some brain nuclei contained higher levels of LPA receptor than others. The majority of LPA receptor-expressing cells were Olig2 oligodendrocytes. In addition, ALDH1l1 astrocytes and CD31 vascular endothelial cells also expressed LPA receptor. By contrast, NeuN neuron and Iba1 microglia expressed little or no LPA receptor. The current neuroanatomical findings will aid in elucidating a role of brain LPA receptor, especially those involved in cognition and emotion.