Introduction: Platelet hyperreactivity associates with cardiovascular events in humans. Studies in mice and humans suggest that prostaglandin E 2 (PGE 2 ) regulates platelet activation. In mice, activation of the PGE 2 receptor subtype 3 (EP3) promotes thrombosis, but the significance of EP3 in humans is less well understood.
We show that a newly developed formulation of DMTS is efficacious within two lethal CN exposure mouse models (inhalation and injection) and is highly effective by intramuscular injection. Within these HCN studies, we demonstrate efficacy of DMTS in both continuous and discontinuous inhalation exposure models.
To determine the contribution of cysteines to the function of the mouse E-prostanoid subtype 3 gamma (mEP3γ), we tested a series of cysteine-to-alanine mutants. Two of these mutants, C107A and C184A, showed no agonist-dependent activation in a cell-based reporter assay for mEP3γ, whereas none of the other cysteine-to-alanine mutations disrupted mEP3γ signal transduction. Total cell membranes prepared from HEK293 cells transfected with mEP3γ C107A or C184A had no detectable radioligand binding. Other mutant mEP3γ receptors had radioligand affinities and receptor densities similar to wild-type. Cell-surface ELISA against the N-terminal HA-tag of C107A and C184A demonstrated 40 % and 47 % reductions respectively in receptor protein expression at the cell surface, and no radioligand binding was detected as assessed by intact cell radioligand binding experiments. These data suggest a key role for C107 and C184 in both receptor structure/stability and function and is consistent with the presence of a conserved disulfide bond between C107 and C184 in mouse EP3 that is required for normal receptor expression and function. Our results also indicate that if a second disulfide bond is present in the native receptor it is non-essential for receptor assembly or function.
Recent preclinical studies demonstrate a role for the prostaglandin E2 (PGE2) subtype 1 (EP1) receptor in mediating, at least in part, the pathophysiology of hypertension and diabetes mellitus. A series of amide and N-acylsulfonamide analogs of a previously described picolinic acid-based human EP1 receptor antagonist (7) were prepared. Each analog had improved selectivity at the mouse EP1 receptor over the mouse thromboxane receptor (TP). A subset of analogs gained affinity for the mouse PGE2 subtype 3 (EP3) receptor, another potential therapeutic target. One analog (17) possessed equal selectivity for EP1 and EP3, displayed a sufficient in vivo residence time in mice, and lacked the potential for acyl glucuronide formation common to compound 7. Treatment of mice with 17 significantly attenuated the vasopressor activity resulting from an acute infusion of EP1 and EP3 receptor agonists. Compound 17 represents a potentially novel therapeutic in the treatment of hypertension and diabetes mellitus.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.