Expression of phospholipase C genes in cultured endothelial cells

During inflammation, endothelial cells (EC) are the first elements to be exposed to mediators circulating in the bloodstream. EC react with finely tuned responses mediated by different pathways, including the Phosphoinositide (PI) signal transduction system. The PI pathway contributes to a variety of cell functions, including hormone secretion, neurotransmitter signal transduction, cell growth, membrane trafficking, ion channel activity, cytoskeleton regulation, cell cycle control, apoptosis, embryonic development, organogenesis, and cell/tissue polarity. The Phosphoinositide-specific phospholipase C (PI-PLC) enzymes contribute to the regulation of the spatio-temporal balance of molecules belonging to the PI system. Thirteen mammalian PI-PLC enzymes have been identified, divided into six sub-families on the basis of amino acid sequence, domain structure and mechanism of recruitment. Isoforms within sub-families share sequence similarity, common domain organization, and general regulatory mechanism. The expression of PI-PLCs is strictly tissue specific, and evidences suggest that it varies under different conditions, such as tumor progression or cell activation. We obtained the complete panel of expression of PI-PLC isoforms in human umbilical vein endothelial cells (HUVEC), a widely used experimental model for EC. Then, we analyzed the mRNA concentration of PI-PLCs in LPS treated HUVEC by using the multiliquid bioanalyzer methodology after 3, 6, 24 48 and 72 hours from LPS administration. Marked differences in the expression of most PI-PLC codifying genes were evident

The phosphoinositides signal transduction pathway in astrocytes

Signal transduction from plasma membrane to cell nucleus is a complex process depending on various components including lipid signaling molecules. Phosphoinositides (PI) constitute an important signaling system. Enzymes related to the PI signal transduction pathway may act at cell periphery, plasma membrane or nuclear level. The PI cycle was also hypothesized to be involved in neuronal as well as glial activities. Many evidences support the hypothesis that the PI cycle is involved in astrocytes activation during the neurodegeneration process. Phosphoinositide-specific phospholipase C (PI-PLC) family of enzymes is crucial in PI signaling system. In fact, PI-PLC enzymes regulate the spatial and temporal balance of PI. Thirteen mammalian PI-PLC isoforms were identified, divided into six sub-families on the basis of amino acid sequence, domain structure and mechanism of recruitment in response to activated receptors: β(1–4), γ(1, 2), δ(1, 3, 4), ϵ(1), ζ(1), and η(1-2). Different expression of the isoforms was described in pathological cells with respect to the corresponding normal counterparts. The expression panel of PI-PLC isoforms varies under different conditions, such as tumoral progression or inflammatory activation, with respect to the quiescent astrocytes counterpart. These observations suggest that in the nervous system the fine regulation of PI-PLC isoforms play a role in the activation of the glia and in the inflammation processes

Phosphoinositide-specific Phospholipase C b1 gene deletion in bipolar disorder affected patient.

The involvement of phosphoinositides (PI) signal transduction pathway and related molecules, such as the Phosphoinositide-specific Phospholipase C (PI-PLC) enzymes, in the pathophysiology of mood disorders is corroborated by a number of recent evidences. Our previous works identified the deletion of PLCB1 gene, which codifies for the PI-PLC beta1 enzyme, in 4 out 15 patients affected with schizophrenia, and no deletion both in major depression affected patients and in normal controls. By using interphase fluorescent in situ hybridization methodology, we analyzed PLCB1 in paraffin embedded samples of orbito-frontal cortex of 15 patients affected with bipolar disorder. Deletion of PLCB1 was identified in one female patient

Peribronchial innervation of the rat lung

Mammalian peribronchial tissue is supplied by several peptide-containing nerve fibers. Although it is well established that different neuropeptides exert significant effects on bronchial and vascular tone in the lungs, the role played by some neuromediators on the general regulation, differentiation and release of locally active substances is still controversial. We studied the innervation of rat peribronchial tissue by immunohistochemical techniques. The immunoperoxidase method with nickel amplification was applied to detect the distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), while the cholinacetyltransferase immunoreactivity was studied by immunohistochemistry. A slight immunoreactivity for NT receptors is observed in lung bronchial epithelium. There is increasing evidence that NTs may act with a paracrine mechanism regulating functional activity of neuronal and non-neuronal structures. A specific immunoreactivity for NTs and NT receptors was also demonstrated within different layers of large, medium and small sized intrapulmonary arteries and veins, according to a recent study of our group. Moreover our data describe the expression of NTs and NT receptors in lymphoid aggregates of the lung (BALT) in which both lymphocytes and macrophages express TrkA receptor and synthesize NTs. Our results show the presence of an extensive network of innervation in the rat peribronchial tissue, confirming a morphological basis for a possible neural modulation of the respiratory mucosa and the physiological/pathophysiological mechanisms of the lung

Peribronchial innervation of the rat lung

Mammalian peribronchial tissue is supplied by several peptide-containing nerve fibers. Although it is well established that different neuropeptides exert significant effects on bronchial and vascular tone in the lungs, the role played by some neuromediators on the general regulation, differentiation and release of locally active substances is still controversial. We studied the innervation of rat peribronchial tissue by immunohistochemical techniques. The immunoperoxidase method with nickel amplification was applied to detect the distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), while the cholinacetyltransferase immunoreactivity was studied by immunohistochemistry. A slight immunoreactivity for NT receptors is observed in lung bronchial epithelium. There is increasing evidence that NTs may act with a paracrine mechanism regulating functional activity of neuronal and non-neuronal structures. A specific immunoreactivity for NTs and NT receptors was also demonstrated within different layers of large, medium and small sized intrapulmonary arteries and veins, according to a recent study of our group. Moreover our data describe the expression of NTs and NT receptors in lymphoid aggregates of the lung (BALT) in which both lymphocytes and macrophages express TrkA receptor and synthesize NTs. Our results show the presence of an extensive network of innervation in the rat peribronchial tissue, confirming a morphological basis for a possible neural modulation of the respiratory mucosa and the physiological/pathophysiological mechanisms of the lung