Arachidonic acid lipoxygenation may mediate interleukin-1 stimulation of nerve growth factor secretion in astroglial cultures
✍ Scribed by Dr. M. Čarman-Krž; Dr. Bradley C. Wise
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 763 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0360-4012
No coin nor oath required. For personal study only.
✦ Synopsis
Interleukin-lp (IL-1) stimulates by about fivefold NGF secretion from rat neonatal cortical astrocytes in primary culture. We investigated the possible intracellular second messenger mechanisms involved in the IL-1 induced NGF secretion. Basal NGF secretion did not require extracellular Ca2+, whereas Ca2+ was necessary for the maximal NGF secretion stimulated by IL-1 (10 unitdml). The protein kinase C activator TPA stimulated by sixfold NGF secretion, but in this case, TPA acted synergistically with IL-1 to increase NGF secretion. Treatment of cells with the phospholipase A, inhibitor mepacrine (30 pM) inhibited basal (by 50%) and IL-1 stimulated (by 80%) NGF secretion. Indomethacin, a cyclooxygenase inhibitor, produced a slight increase in basal NGF secretion at low concentrations, while PGE, (10 pM) inhibited basal and IL-1 stimulated NGF secretion. In contrast, treatment of cells with nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, blocked in a concentration-dependent manner (IC5,, = 10 pM) IL-1 stimulation of NGF secretion. The leukotriene LTB, increased basal NGF secretion and this effect was not additive with IL-1 when both agents were added at saturating concentrations, indicating a common mechanism of action for these two agents. Thus, one possible mechanism by which IL-1 stimulates NGF secretion from astrocytes is by activation of the phospholipase A,-lipoxygenase pathway.