Compound 21(UIOWA)

Women with a history of preeclampsia (hxPE) have a ≥4-fold risk for developing cardiovascular disease (CVD) compared with women who had a healthy pregnancy (hxHC). HxPE have exaggerated vasoconstrictor sensitivity to angiotensin (ang) II after pregnancy, which likely contributes to CVD progression after preeclampsia. Ang II-mediated constriction via ang II type 1 receptors (AT1R) is countered by vasodilatory ang II type 2 receptors (AT2R); however, the extent to which reductions in AT2R-mediated responses contribute to exaggerated ang II-mediated constriction after preeclampsia remains unknown. We examined the balance of AT1R- and AT2R-mediated responses in hxPE and hxHC (n=12/group). We hypothesized that (1) attenuated AT2R-mediated dilation would be improved with AT1R inhibition in hxPE, and (2) AT2R inhibition would increase ang II-mediated constriction in hxHC but have no effect in hxPE. We measured cutaneous vascular conductance responses to compound 21 (AT2R agonist; 10-14–10-8mol/L) alone or with losartan (AT1R antagonist; 43 μmol/L) to assess AT2R-mediated dilation, and ang II (10−20–10−4 mol/L) alone or with PD-123319 (AT2R antagonist; 1 μmol/L) to assess the role of AT2R in vasoconstrictor sensitivity to ang II. Reduced AT2R-mediated dilation in hxPE (P=0.002) was improved with AT1R inhibition (P<0.001). Vasoconstrictor sensitivity to ang II was greater in hxPE compared with hxHC (P<0.001). Circulating AT1R agonistic autoantibodies (AT1-AA) were elevated in hxPE (P=0.015). AT2R inhibition increased the vasoconstrictor response to ang II in hxHC (P<0.001) but had no effect in hxPE (P=0.19). These data suggest that hxPE has reduced AT2R-mediated dilation that contributes to increased ang II vasoconstrictor sensitivity after preeclampsia.

Upon the activation of inflammasomes, inflammatory caspases cleave and activate gasdermin D (GSDMD), leading to pore formation that causes cell membrane rupture and amplifies downstream inflammatory responses. Dysregulated inflammasome activation and pyroptosis signaling pathways are implicated in numerous inflammatory diseases. In our work, a set of novel thiazole amide compounds with inhibitory activity against NLRP3 inflammasome-induced pyroptosis was identified. Of all the compounds tested, compound 21 demonstrated the most potent anti-pyroptotic effects. It suppressed GSDMD cleavage and decreased IL-1β and lactate dehydrogenase (LDH) release in a concentration-dependent manner. Compound 21 bound to NLRP3 protein and increased the thermal stability of NLRP3 concentration-dependently. The molecular docking and dynamics simulations revealed that compound 21 binds to the NLRP3 protein's active site, suppressing inflammasome activation. Further investigations showed that compound 21 also partially blocked upstream NF-κB signaling and downstream GSDMD N-terminal domain (GSDMD-NT) oligomerization, which explains its broad inhibitory effects on pyroptosis driven by multiple inflammasomes. Overall, this study presents a promising thiazole amide compound with inhibitory activity against inflammasome activation and subsequent pyroptosis, warranting further exploration.