In vitro sepsis up-regulates Nociceptin/Orphanin FQ receptor expression and function on human T- but not B-cells.

BACKGROUND AND PURPOSE: In animal models of sepsis, increased activation of the Nociceptin/Orphanin FQ (N/OFQ) receptor NOP is associated with mortality and NOP antagonists improved survival. We have explored the role of the N/OFQ-NOP system in freshly isolated volunteer human B- and T-cells incubated with lipopolysaccharide (LPS) and peptidoglycan G (PepG) as a model of in vitro sepsis. EXPERIMENTAL APPROACH: B- and T-cell NOP expression was measured using the NOP fluorescent probe N/OFQATTO594 , N/OFQ content was measured using immunofluorescence, N/OFQ release was tracked using a CHOhNOPGαiq5 biosensor assay and NOP function was measured using transwell migration and cytokine/chemokine release using a 25-plex assay format. Cells were challenged with LPS/PepG. KEY RESULTS: CD19-positive B-cells bound N/OFQATTO594 ; they also contain N/OFQ. Stimulation with CXCL13/IL-4 increased N/OFQ release. N/OFQ trended to reduced migration to CXCL13/IL-4. Surface NOP expression was unaffected by LPS/PepG, but this treatment increased GM-CSF release in an N/OFQ sensitive manner. CD3-positive T-cells did not bind N/OFQATTO594 ; they did contain N/OFQ. Stimulation with CXCL12/IL-6 increased N/OFQ release. When incubated with LPS/PepG, NOP surface expression was induced leading to N/OFQATTO594 binding. In LPS/PepG-treated cells, N/OFQ reduced migration to CXCL12/IL-6. LPS/PepG increased GM-CSF release in an N/OFQ sensitive manner. CONCLUSIONS AND IMPLICATIONS: We suggest both a constitutive and sepsis-inducible N/OFQ-NOP receptor autocrine regulation of B- and T-cell function, respectively. These NOP receptors variably inhibit migration and reduce GM-CSF release. These data provide mechanistic insights to the detrimental role for increased N/OFQ signalling in sepsis and suggest a potential role for NOP antagonists as treatments.

Reduced placental vascular reactivity to 5-hydroxytryptamine in pre-eclampsia and the status of 5HT(2A) receptors.

This study investigates the contractile response to 5 hydroxytryptamine (5HT) of chorionic artery and vein segments from normotensive (NT) and pre-eclamptic (PE) placentae. It also looked at the effectiveness of ketanserin (KET), a 5HT(2A) receptor antagonist, in reducing 5HT-mediated vasoconstriction. 5HT induced vasoconstriction in all of the vessels was studied. Compared to NT vessels, Emax (%KCl) was significantly reduced in PE arteries (p<0.05) and veins (p<0.0005). The mean Emax for NT arteries was 104.1 (±10.71) whilst PE arteries showed a mean Emax of 57.02 (±12.13). KET produced a statistically significant reduction of Emax in both vessels in NT and the arteries in PE. However the antagonistic effect of KET was not pronounced in PE veins. The EC50 values for NT and PE arteries and veins did not change significantly. There were no noticeable changes in the expression profiles of 5HT(2A) receptor mRNA and protein expressions. The data from this study suggest that in PE, the vascular reactivity of chorionic vessels to 5HT is reduced and it was not due to the altered expression of 5HT(2A) receptors.