Anti-inflammatory effects of levalbuterol-induced 11β-hydroxysteroid dehydrogenase type 1 activity in airway epithelial cells

11β-Hydroxysteroid dehydrogenase type 1 amplifies inflammation in LPS-induced THP-1 cells

Objectives

The role of glucocorticoids as anti-inflammatory and immune-stimulatory drugs has been widely reported. However, the role of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which catalyzes the conversion of inactive cortisone into active cortisol, in inflammation remains unclear. This study aimed to examine the mechanism of actions of 11β-HSD1 in lipopolysaccharide (LPS)-induced THP-1 cells.

Materials and Methods

The gene expression of 11β-HSD1 and pro-inflammatory cytokines was detected via RT-PCR. The protein expression of IL-1β in cell supernatants was detected via ELISA. Oxidative stress and mitochondrial membrane potential were assessed using a reactive oxygen species (ROS) kit and a mitochondrial membrane potential (MMP) kit, respectively. The expression of Nuclear Factor- Kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) was detected via western blotting.

Results

Elevated levels of 11β-HSD1 contributed to the expression of inflammatory cytokines, whereas BVT.2733, a selective 11β-HSD1 inhibitor, ameliorated inflammatory responses, ROS, and mitochondrial damage in LPS-stimulated THP-1 cells. Furthermore, cortisone and cortisol, which are the substrate and product of 11β-HSD1, respectively, showed biphasic responses and induced the expression of pro-inflammatory cytokines at a low concentration in both LPS-stimulated or untreated THP-1 cells. The enhanced inflammation was attenuated by co-treatment with BVT.2733 and the glucocorticoid receptor (GR) antagonist RU486, but not in those treated with the mineralocorticoid receptor (MR) antagonist spironolactone. Overall, the results indicate that 11β-HSD1 amplifies inflammatory responses by activating the NF-κB and MAPK signaling pathways.

Conclusion

Inhibition of 11β-HSD1 may serve as a potential therapeutic target against the excessive activation of inflammation.

2-Phenethylamines in Medicinal Chemistry: A Review

A concise review covering updated presence and role of 2-phenethylamines in medicinal chemistry is presented. Open-chain, flexible alicyclic amine derivatives of this motif are enumerated in key therapeutic targets, listing medicinal chemistry hits and appealing screening compounds. Latest reports in discovering new bioactive 2-phenethylamines by research groups are covered too.

18β-Glycyrrhetinic acid suppresses allergic airway inflammation through NF-κB and Nrf2/HO-1 signaling pathways in asthma mice

18β-Glycyrrhetinic acid (18β-GA), the main bioactive component of Glycyrrhizae Radix, is considered a promising anti-inflammatory and antioxidant agent. Here, we evaluated the anti-inflammatory and antioxidant effects of 18β-GA in an ovalbumin (OVA)-induced asthma mouse model, and examined the role of NF-κB and Nrf2/HO-1 signaling pathways. The histopathological changes of lung tissue in mouse were assessed by histochemical staining and counting of inflammatory cells. The levels of IgE and inflammatory cytokines in the bronchoalveolar lavage fluid of mice were detected by ELISA. In OVA-induced asthmatic mice, 18β-GA treatment can significantly improve lung function and reduce lung inflammation including infiltration of inflammatory cells. In addition, 18β-GA reduced the OVA-induced NF-κB phosphorylation in lungs of mice while increasing the expression of Nrf2 and HO-1. These results indicate that 18β-GA protects OVA-induced allergic inflammation of airway by inhibiting phosphorylation of NF-κB and enhancing the Nrf2/HO-1 pathway, and serves as a potential treatment option for allergic inflammation of airway.

In obese mice, exercise training increases 11β-HSD1 expression, contributing to glucocorticoid activation and suppression of pulmonary inflammation

Exercise training is advocated for treating chronic inflammation and obesity-related metabolic syndromes. Glucocorticoids (GCs), the anti-inflammatory hormones, are synthesized or metabolized in extra-adrenal organs. This study aims to examine whether exercise training affects obesity-associated pulmonary inflammation by regulating local GC synthesis or metabolism. We found that sedentary obese (ob/ob) mice exhibited increased levels of interleukin (IL)-1β, IL-18, monocyte chemotactic protein (MCP)-1, and leukocyte infiltration in lung tissues compared with lean mice, which was alleviated by 6 wk of exercise training. Pulmonary corticosterone levels were decreased in ob/ob mice. Exercise training increased pulmonary corticosterone levels in both lean and ob/ob mice. Pulmonary corticosterone levels were negatively correlated with IL-1β, IL-18, and MCP-1. Immunohistochemical staining of the adult mouse lung sections revealed positive immunoreactivities for the steroidogenic acute regulatory protein, the cholesterol side-chain cleavage enzyme (CYP11A1), the steroid 21-hydroxylase (CYP21), 3β-hydroxysteroid dehydrogenase (3β-HSD), and type 1 and type 2 11β-hydroxysteroid dehydrogenase (11β-HSD) but not for 11β-hydroxylase (CYP11B1). Exercise training significantly increased pulmonary 11β-HSD1 expression in both lean and ob/ob mice. In contrast, exercise training per se had no effect on pulmonary 11β-HSD2 expression, although pulmonary 11β-HSD2 levels in ob/ob mice were significantly higher than in lean mice. RU486, a glucocorticoid receptor antagonist, blocked the anti-inflammatory effects of exercise training in lung tissues of obese mice and increased inflammatory cytokines in lean exercised mice. These findings indicate that exercise training increases pulmonary expression of 11β-HSD1, thus contributing to local GC activation and suppression of pulmonary inflammation in obese mice.NEW & NOTEWORTHY Treadmill training leads to a significant increase in pulmonary corticosterone levels in ob/ob mice, which is in parallel with the favorable effects of exercise on obesity-associated pulmonary inflammation. Exercise training increases pulmonary 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) expression but has no significant effect on 11β-HSD2 expression in both lean and ob/ob mice. These findings indicate that exercise training increases pulmonary expression of 11β-HSD1, thus contributing to local glucocorticoid activation and suppression of pulmonary inflammation in obese mice.