Immunohistochemical Localization of Phospholipase D1 in Developing Rat Forebrain / 대한해부학회지

Phospholipase D (PLD), one of the intracellular signal transduction enzymes, may play an important role in developing brain. However, the developmental regulation of PLD protein has not been determined. In the present study, we investigated the temporal and spatial expression of PLD isozyme, PLD1 in the developing rat forebrain using an affinity-purified peptide antibody against PLD1. Our data showed that immunoreactivity for PLD1 was first seen in the germinal zone of the lateral ventricle, differentiating neurons and their processes at embryonic day 18 (E18). At E20, clusters of immunoreactive cells were observed in the medial germinal zone of the lateral ventricle, restricted zones of the frontal and parietal cortex, the nuclei of the medial septum and the diagonal band. During the first postnatal week, there was an increase in the number and staining intensity of the immunoreactive neurons in the cerebral cortex, which peaked at postnatal day 7 (P7). During the second postnatal week, there was an abrupt decrease in the number of immunoreactive cortical pyramidal neurons. By P14, only a few of the pyramidal neurons in cerebral cortex layer V were immunoreactive. These results revealed that expression of PLD1 protein at various stages of development of the septum and cerebral cortex is differentially regulated. This suggests that PLD1 may regulate the developmental processes of some neuronal populations.

Localization of phospholipase D genes on the human chromosome and various tissues of rat / 대한해부학회지

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine to phosphatidic acid and choline. A variety of signal molecules such as hormones, neurotransmitters, extracellular matrix molecules, and growth factors are known to induce the activation of PLD in a wide range of cell types. Hence PLD is implicated in a broad spectrum of physio-logical processes and diseases, including mitogenesis, cell differentiation, metabolic regulation, secretion, neural and cardiac stimulation, inflammation, oncogenesis, and diabetes. The signal-dependent activation of PLD has been observed in a variety of brain and neural-derived cells. In this paper, human chromosomal locations and developmental neural expression patterns in rat of PLD1 and PLD2 were investigated with fluorescent in situ hybridization (FISH) and in situ hybridization histochemistry, respectively. The PLD1 was assigned to human chromosome 3q26 and expressed most strikingly in selected ventricular neural cells lining spinal cord and brain during neuronal differentiation and migration period. The PLD2 was assigned to human chromosome 17p13.1 and expressed in differentiating ventricular neural cells and multiple regions of the postnatal rat brain.