Macrophage Inactivation by Small Molecule Wedelolactone via Targeting sEH for the Treatment of LPS-Induced Acute Lung Injury

Abstract

Soluble epoxide hydrolase (sEH) plays a critical role in inflammation by modulating levels of epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids (EpFAs). Here, we investigate the possible role of sEH in lipopolysaccharide (LPS)-mediated macrophage activation and acute lung injury (ALI). In this study, we found that a small molecule, wedelolactone (WED), targeted sEH and led to macrophage inactivation. Through the molecular interaction with amino acids Phe362 and Gln384, WED suppressed sEH activity to enhance levels of EETs, thus attenuating inflammation and oxidative stress by regulating glycogen synthase kinase 3beta (GSK3β)-mediated nuclear factor-kappa B (NF-κB) and nuclear factor E2-related factor 2 (Nrf2) pathways in vitro. In an LPS-stimulated ALI animal model, pharmacological sEH inhibition by WED or sEH knockout (KO) alleviated pulmonary damage, such as the increase in the alveolar wall thickness and collapse. Additionally, WED or sEH genetic KO both suppressed macrophage activation and attenuated inflammation and oxidative stress in vivo. These findings provided the broader prospects for ALI treatment by targeting sEH to alleviate inflammation and oxidative stress and suggested WED as a natural lead candidate for the development of novel synthetic sEH inhibitors.

Tackling Severe Neutrophilic Inflammation in Airway Disorders with Functionalized Nanosheets

“…Having demonstrated that cfDNA is a potential biomarker of airway inflammation, our study aimed to explore the therapeutic potential of targeting cfDNA in the treatment of respiratory inflammatory disorders. To accomplish this, we established a mouse model with airway inflammation via intranasal lipopolysaccharide (LPS) instillation following the established protocol described in the literature. , Nasal lavage fluid (NALF) and bronchoalveolar lavage fluid (BALF) were collected at 24 h postinstillation for further analysis. In addition to elevated cfDNA concentrations (increase around 3-fold), significantly increased levels of several inflammatory cytokines were observed in NALF and BALF after LPS instillation (Figures G,H and S2 and S3).…”

“…Treatment of Model Mice with DNase. In the first step, the airway inflammation mouse model was established in accordance with the above protocol, 34,35 and mice instilled with saline were used as a sham group. In the second step, DNase (10 U) or DNase (20 U) in 30 μL of saline was intranasally administered to the mice with airway inflammation after 6 h. The sham mice and mice with airway inflammation were treated with 30 μL of saline and were used as negative and positive controls, respectively.…”

“…A mouse model of airway inflammation was established according to a previous report. , Mice were sedated using isoflurane carried by oxygen before 1 μg of LPS (dissolved in 30 μL of saline) was instilled intranasally. Sham mice were intranasally instilled with 30 μL of PBS.…”

“…Treatment of Model Mice with BP-PGA 50 Nanosheets, PGA 50 NPs, and Blank BP Sheets. The airway inflammation mouse model was established in accordance with the above protocol, 34,35 and mice instilled with saline were used as a sham group. BP-PGA 50 (100 μg), PGA 50 NPs (100 μg), or BP sheets (100 μg) in 30 μL of saline were instilled after 6 h. Sham mice and mice with airway inflammation instilled with 30 μL of saline were utilized as negative and positive controls, respectively.…”

“…The nasal mucosa of the above experimental mice was collected, and total mRNA was extracted using TRIzol. 35 Then, mRNA was converted to cDNA with an iScript cDNA synthesis kit. Subsequently, iTaq Universal SYBR Green Supermix was used to conduct qRT-PCR, and Ct values for cytokines (IL-1β, IL-6, and TNF-α) were normalized to GAPDH.…”