| 1. |
- Alling, Christer, et al.
(author)
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Adaptation of signal transduction in brain
- 1994
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In: EXS. - 1023-294X. ; 71, s. 19-28
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Journal article (peer-reviewed)abstract
- Cell culture models were used to study the effects of long-term ethanol exposure on neuronal cells. Effects on phospholipase C and phospholipase D mediated signal transduction were investigated by assaying receptor-binding, G protein function, activities of lipases, formation of second messengers and c-fos mRNA. The signal transduction cascades displayed abnormal activities from 2 to 7 days of exposure which differed from the acute effects. Phosphatidylethanol formed by phospholipase D is an abnormal lipid that may harmfully affect nerve cell function.
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| 2. |
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| 3. |
- Lundqvist, C, et al.
(author)
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Phosphatidylethanol affects inositol 1,4,5-trisphosphate levels in NG108-15 neuroblastoma x glioma hybrid cells
- 1993
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In: Journal of Neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 60:2, s. 738-744
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Journal article (peer-reviewed)abstract
- Phosphatidylethanol is formed by phospholipase D in animal cells exposed to ethanol. Previous reports have demonstrated that the degradation of phosphatidylethanol is slow, indicating that this lipid may be present in the cells after ethanol itself has disappeared. Accumulation of an abnormal alcohol metabolite may influence cellular functions. In the present study, cultivation of NG108-15 neuroblastoma x glioma hybrid cells in the presence of ethanol resulted in an accumulation of phosphatidylethanol and a simultaneous increase in basal inositol 1,4,5-trisphosphate levels. The direct effects of phosphatidylethanol on the phosphoinositide signal transduction system were examined through incorporation of exogenous phosphatidylethanol into membranes of ethanol-naive cells. An incorporation amounting to 2.8% of cellular phospholipids was achieved after a 5-h incubation with 30 microM phosphatidylethanol. Phosphatidylethanol was found to cause a time- and dose-dependent increase in the basal levels of inositol 1,4,5-trisphosphate. The effects on inositol 1,4,5-trisphosphate levels of exogenously added phosphatidylethanol and ethanol exposure for 2 days were not additive. No effect on bradykinin-stimulated inositol 1,4,5-trisphosphate production could be detected. However, the increase in basal inositol 1,4,5-trisphosphate levels indicates that phosphatidylethanol affects inositol 1,4,5-trisphosphate turnover and emphasizes the importance of considering phosphatidylethanol as a possible mediator of ethanol-induced effects on cellular processes.
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| 4. |
- Söderström, K, et al.
(author)
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High expression of V gamma 8 is a shared feature of human gamma delta T cells in the epithelium of the gut and in the inflamed synovial tissue.
- 1994
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In: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 152:12, s. 6017-27
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Journal article (peer-reviewed)abstract
- We have analyzed the V-gene usage in gamma delta T cells of the human gut and joint by using a new mAb (B18) specific for V gamma 8 of human TCR-gamma delta+ T cells. The B18+ population constituted a minor subset of the gamma delta T cells in peripheral blood (PB) of healthy persons (6 +/- 5%) and only 1 of 35 gamma delta T cell clones analyzed was positive. In contrast, the B18+ subset was a dominant gamma delta T cell population among intraepithelial lymphocytes (IEL) derived from the human intestine (74 +/- 29, p < 0.002), and two of three IEL clones from patients with coeliac disease were B18+. Interestingly, a higher proportion of B18+ gamma delta T cells was found in the synovial fluid of patients with rheumatoid arthritis (RA) (21 +/- 18%, 0.02 < p < 0.05) compared with normal PB. Furthermore, the B18+ subset was more frequent among IL-2-expanded gamma delta T cells (42 +/- 20%) derived from synovial tissue than among IL-2-expanded cells derived from synovial fluid (p < 0.002) and PB from RA patients (p < 0.02) as well as normal PB (p < 0.002). The V-gene usage of 13 gamma delta T cell clones from the synovial fluid of arthritic patients was analyzed. All B18+ clones (n = 7) expressed mRNA for V gamma 8 together with mRNA for V delta 1 (n = 5) or mRNA for V delta 3 (n = 2). None of the B18- clones expressed V gamma 8 (n = 6). We conclude that the gamma delta T cell that expresses V gamma 8, together with mainly V delta 1, is a major gamma delta T cell subset among the IEL of the gut and a highly frequent subset in the synovial tissue of patients with RA. This subset may correspond to the mouse V gamma 7+ IEL, which has a high degree of amino acid sequence homology with the human V gamma 8 protein.
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