NLRP3 plays a role in vascular diseases. Corpora cavernosa (CC) is an extension of the vasculature. We hypothesize that NLRP3 plays a deleterious role in CC relaxation. Male C57BL/6 (WT) and NLRP3 deficient (NLRP3−/−) mice were used. Intracavernosal pressure (ICP/MAP) measurement was performed. Functional responses were obtained from CC strips of WT and NLRP3−/− mice before and after MCC950 (NLRP3 inhibitor) or LPS + ATP (NLRP3 stimulation). NLRP3, caspase-1, IL-1β, eNOS, nNOS, guanylyl cyclase-β1 (GCβ1) and PKG1 protein expressions were determined. ICP/MAP and sodium nitroprusside (SNP)-induced relaxation in CC were decreased in NLRP3−/− mice. Caspase-1, IL-1β and eNOS activity were increased, but PKG1 was reduced in CC of NLRP3−/−. MCC950 decreased non-adrenergic non-cholinergic (NANC), acetylcholine (ACh), and SNP-induced relaxation in WT mice. MCC950 did not alter NLRP3, caspase-1 and IL-1β, but reduced GCβ1 expression. Although LPS + ATP decreased ACh- and SNP-, it increased NANC-induced relaxation in CC from WT, but not from NLRP3−/− mice. LPS + ATP increased NLRP3, caspase-1 and interleukin-1β (IL-1β). Conversely, it reduced eNOS activity and GCβ1 expression. NLRP3 plays a dual role in CC relaxation, with its inhibition leading to impairment of nitric oxide-mediated relaxation, while its activation by LPS + ATP causes decreased CC sensitivity to NO and endothelium-dependent relaxation.

In the present study, we hypothesized that endothelin (ET) receptors (ET A and ET B ) stimulation, through increased calcium and ROS formation, leads to Nucleotide Oligomerization Domain-Like Receptor Family, Pyrin Domain Containing 3 (NLRP3) activation. Intracavernosal pressure (ICP/MAP) was measured in C57BL/6 (WT) mice.Functional and immunoblotting assays were performed in corpora cavernosa (CC) strips from WT, NLRP3 −/− and caspase −/− mice in the presence of ET-1 (100 nM) and vehicle, MCC950, tiron, BAPTA AM, BQ123, or BQ788. ET-1 reduced the ICP/MAP in WT mice, and MCC950 prevented the ET-1 effect. ET-1 decreased CC ACh-, sodium nitroprusside (SNP)-induced relaxation, and increased caspase-1 expression.BQ123 an ET A receptor antagonist reversed the effect. The ET B receptor antagonist BQ788 also reversed ET-1 inhibition of ACh and SNP relaxation. Additionally, tiron, BAPTA AM, and NLRP3 genetic deletion prevented the ET-1-induced loss of ACh and SNP relaxation. Moreover, BQ123 diminished CC caspase-1 expression, while BQ788 increased caspase-1 and IL-1β levels in a concentration-dependent manner (100 nM-10 μM). Furthermore, tiron and BAPTA AM prevented ET-1-induced increase in caspase-1. In addition, BAPTA AM blocked ET-1-induced ROS generation. In conclusion, ET-1-induced erectile dysfunction depends on ET A -and ET B -mediated activation of NLRP3 in mouse CC via Ca 2+ -dependent ROS generation.

MENDES, AC. Glycosylation with O-linked β-N-acetylglucosamine (O-GlcNAc) andevents that contribute to atherosclerotic plaque formation. 2020. 166 p. Dissertation

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Background and Purpose: Endothelin-1 (ET-1) and Nucleotide Oligomerization Domain-Like Receptor Family, Pyrin Domain Containing 3 (NLRP3) play an essential role in erectile dysfunction. ET-1 and NLRP3 activate inflammatory processes by increasing calcium (Ca) and reactive oxygen species (ROS). In the present study, we hypothesized that endothelin receptors (ET and ET) stimulation, through increased calcium and ROS formation, leads to NLRP3 activation. Experimental approach: Intracavernosal pressure (ICP/MAP) was measured in C57BL/6 (WT) mice. Functional and immunoblotting assays were performed in corpora cavernosa (CC) strips from WT, NLRP3 and caspase mice after ET-1 (100 nM) stimulation in the presence of vehicle, MCC950, tiron, BAPTA AM, BQ123, or BQ788. Key Results: ET-1 gradually reduced the ICP/MAP in WT mice, and MCC950 administration prevented the effect of ET-1. ET-1 decreased CC relaxation to ACh and sodium nitroprusside (SNP) and increased caspase-1 protein expression, effects reversed by the ET receptor antagonist BQ123. The ET receptor antagonist BQ788 also reversed the effect of ET-1 on ACh and SNP relaxation. Additionally, tiron, BAPTA AM, and NLRP3 genetic deletion prevented the ET-1-induced loss of ACh and SNP relaxation. Moreover, BQ123 diminished CC caspase-1 expression, while BQ788 increased caspase-1 and IL-1β levels in a concentration-dependent manner (100 nM to 10 µM). Furthermore, tiron and BAPTA AM prevented ET-1-induced increase in caspase-1. In addition, BAPTA AM blocked ET-1-induced ROS generation. Conclusion and Implications: NLRP3 activation contributes to acute ET-1-induced erectile dysfunction by mechanisms that depend on ET- and ET-induced Ca influx and ROS generation.