PFI-3 induces vasorelaxation with potency to reduce extracellular calcium influx in rat mesenteric artery

Jing Li; Xue-Qi Liang; Yun-Feng Cui; Yu-Yang Fu; Zi-Yue Ma; Ying-Tao Cui; Xian-Hui Dong; Hai-Jun Huang; Ting-Ting Tong; Ya-Mei Zhu; Ya-Dong Xue; Yong-Zhen Wang; Tao Ban; Rong Huo

doi:10.7717/peerj.15407

PFI-3 induces vasorelaxation with potency to reduce extracellular calcium influx in rat mesenteric artery

PeerJ. 2023 May 25:11:e15407. doi: 10.7717/peerj.15407. eCollection 2023.

Authors

Affiliations

¹ Department of Pharmacology (The Key Laboratory of Cardiovascular Research, Ministry of Education) at College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang Province, China.
² Department of Pharmacy, Second Affiliated Hospital of Qiqihar Medical College, Qiqihar, Heilongjiang Province, China.

Abstract

Background: PFI-3 is a small-molecule inhibitor that targets the bromodomains (BRDs) of Brahma-related gene 1 (BRG1). This monomeric compound, which has high selectivity and potent cellular effects, has recently been developed. Although PFI-3 has been reported as a potential therapeutic agent targeting thrombomodulin, its role in the regulation of vascular function remains unknown. Therefore, we aimed to investigate the impact of PFI-3 on arterial vessel tone.

Methods: A microvascular tension measurement device (DMT) was utilized to identify alterations in vascular tension within the mesenteric artery. To detect variations in cytosolic [Ca²⁺]_i, a Fluo-3/AM fluorescent probe and fluorescence microscope were employed. Additionally, whole-cell patch clamp techniques were utilized to evaluate the activity of L-type voltage-dependent calcium channels (VDCCs) in cultured arterial smooth muscle cells (A10 cells).

Results: PFI-3 exerted a dose-dependent relaxation effect on rat mesenteric arteries with both intact and denuded endothelium after phenylephrine (PE)- and high-K⁺-induced constriction. PFI-3-induced vasorelaxation was not affected by the presence of L-NAME/ODQ or K⁺ channel blockers (Gli/TEA). PFI-3 abolished Ca²⁺-induced contraction on endothelium-denuded mesenteric arteries preincubated by PE in Ca²⁺-free solution. Incubation with TG had no impact on PFI-3-induced vasorelaxation pre-contracted by PE. PFI-3 reduced Ca²⁺-induced contraction on endothelium-denuded mesenteric arteries pre-incubated by KCl (60 mM) in Ca²⁺-free solution. PFI-3 declined extracellular calcium influx in A10 cells detected by Fluo-3/AM fluorescent probe and fluorescence microscope. Furthermore, we observed that PFI-3 decreased the current densities of L-type VDCC by whole-cell patch clamp techniques.

Conclusions: PFI-3 blunted PE and high K⁺-induced vasoconstriction independent of endothelium on rat mesenteric artery. The vasodilatory effect of PFI-3 may be attributed to its inhibition of VDCCs and receptor-operated calcium channels (ROCCs) on vascular smooth muscle cells (VSMCs).

Keywords: Calcium channels; PFI-3; Vasoconstriction; Vasodilation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Calcium Channels, L-Type / pharmacology
Calcium* / metabolism
Fluorescent Dyes* / pharmacology
Mesenteric Arteries
Rats

Substances

antineoplaston A10
Calcium
Calcium Channels, L-Type
Fluo-3
Fluorescent Dyes

Grants and funding

This work was supported by the National Natural Science Foundation of China (81872870, 82070312 and 31400983), the Scientific Fund of Heilongjiang Province (H2018011), the Scientific Fund of Heilongjiang Province (LH2022H003), and the Heilongjiang Province Postdoctoral Foundation (LBH-Q19155). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.