Biomedical subjects

Dolisha Jones

Publications and source records attributed to Dolisha Jones.

4 recordsLinked to original sources

PubMed2003

Estrogen signaling at the cell surface coupled to nitric oxide release in Mytilus edulis nervous system.

In previous studies we have demonstrated release of nitric oxide (NO) in human tissues following exposure to estrogen. We now designed experiments to determine whether estrogen is present in the neural tissue of Mytilus edulis, a marine mollusk, and whether, as in vertebrates, it stimulates constitutive NO synthase activity. After HPLC purification of 17beta-estradiol (17beta-E(2)) from M. edulis ganglionic tissue, we confirmed the presence of 17beta-E(2) by RIA and ES-Q-TOF-MS analysis. We further found that when either exogenous or endogenous (purified HPLC fraction) 17beta-E(2) was added to pedal ganglia, there was immediate concentration-dependent NO release. Furthermore, 17beta-E(2) conjugated to BSA also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor antagonist, inhibited the action of both 17beta-E(2) and 17beta-E(2) conjugated to BSA, further supporting the presence of an estrogen receptor. In addition, by Western blot analysis with anti-ER-beta antibodies, we observed a 55-kDa protein in both the membrane and cytosolic fractions in pedal ganglia as well as in human leukocytes (that have been previously shown to express ER-beta). In summary, our results suggest that a physiological dose of estrogen acutely stimulates NO release within pedal ganglia via an estrogen cell surface receptor.

Animals↗

PubMedDate not supplied

17-beta estradiol down regulates ganglionic microglial cells via nitric oxide release: presence of an estrogen receptor beta transcript.

OBJECTIVES: In earlier studies we have demonstrated that 17-beta-estradiol and an estrogen cell surface receptor can be found on various human cells where they are coupled to nitric oxide release. We also demonstrated the presence of estrogen signaling in Mytilus edulis ganglia. In the present report, we sought to determine a function for these ganglionic estrogen receptors, transcending a reproductive role for estrogen. MATERIAL & METHODS: Ganglionic microglial egress from excised pedal ganglia was examined microscopically following pharmacological treatments designed to determine a role for 17-beta-estradiol in microglial regulation via nitric oxide. Additionally, we examined the tissue by RT-PCR and sequence analysis for the estrogen receptor beta gene. RESULTS: In ganglia incubated with varying concentrations of 17-beta-estradiol-BSA there is a significant drop in microglial egress at the 24 hour observation period (58.7 +/- 7.4 vs. 17-beta-estradiol-BSA exposed = 14.7 +/- 1.5; P<0.01), which can be antagonized by tamoxifen and significantly diminished by L-NAME, a nitric oxide synthase inhibitor. By RT-PCR and sequence analysis Mytilus edulis pedal ganglia was found to express a 266 bp fragment of the estrogen receptor-beta gene, which exhibits 100% sequence identity with the human counterpart. CONCLUSION: These data suggest that 17-beta-estradiol-BSA is working on estrogen cell surface receptors since 17-beta-estradiol-BSA does not enter the cytoplasm and that these receptors are coupled to constitutive nitric oxide release. This study demonstrates that 17-beta-estradiol can down regulate microglial fMLP induced activation and activation following ganglionic excision.

Animals↗

PubMedDate not supplied

The presence of 17-beta estradiol in Mytilus edulis gonadal tissues: evidence for estradiol isoforms.

OBJECTIVES: In earlier studies, we demonstrate that 17-beta -estradiol and an estrogen cell surface receptor can be found on various human cells, i.e., vascular endothelial, monocytes, and granulocytes, where they are coupled to nitric oxide release. We further demonstrated this phenomenon in the marine mussel Mytilus edulis ganglionic tissues. In the present report we sought to determine if estrogen can be found in M. edulis reproductive tissues. MATERIAL & METHODS: We determined the presence of 17-beta -estradiol via high pressure liquid chromatography (HPLC) and radioimmunoassay (RIA) in the animals gonads. This substance was further identified via nanoelectro-spray ionization quadrupole time of flight mass spectrometry (Q-TOF-MS). RESULTS: 17-beta -estradiol was identified and quantified in Mytilus gonads. Interestingly, we also determined that estradiol isoforms also were present in this tissue. CONCLUSION: These data demonstrate that 17-beta-estradiol and an estradiol isoform is present in M. edulis gonadal tissues, suggesting that they have functions related to reproduction. This further suggests that estrogen's association with reproductive activities has a long evolutionary history and that this association began in invertebrates.

Animals↗

PubMedDate not supplied

Immunocytes modulate ganglionic nitric oxide release which later affects their activity level.

Pedal ganglia excised and maintained in culture for up to 2 h, release NO at low levels. The range can vary between 0 to 1.1 nM. Non-stimulated immunocytes do not significantly stimulate ganglionic NO release when incubated with pedal ganglia. However, ganglia exposed to immunocytes that had been previously activated by a 30 min incubation with interleukin 1 beta, release NO significantly above basal levels. In these experiments, 91 +/- 2.5% of the non-stimulated immunocytes exhibited form factors in the 0.72 to 0.89 range (sampled prior to ganglionic addition), whereas 62 +/- 10.3% of the interleukin 1 beta stimulated immunocytes had form factors in the 0.39 to 0.49 range, demonstrating activation. Addition of the nitric oxide synthase inhibitor, L-NAME (10(-4) M), inhibited basal ganglionic NO release as well as that initiated by exposing the ganglia to activated immunocytes. Interestingly, non activated immunocytes, following ganglionic exposure, exhibited activity levels in the 13% range, representing a non significant increase. Cells exposed to interleukin 1 beta had a 65% activity level at the beginning of the experiment, followed by a drop of activity to 19 +/- 3.2% after ganglionic exposure. Repeating this last observation in the presence of L-NAME (10(-4) M), brought the activity level of the immunocytes back to the pre-ganglionic exposure level of activity, demonstrating that ganglionic NO was involved in down regulating immunocyte activity.

Animals↗