Inhibitory effect of mabuterol on proliferation of rat ASMCs induced by PDGF-BB via regulating [Ca2+]i and mitochondrial fission/fusion

New insights into the relationship of mitochondrial metabolism and atherosclerosis

Atherosclerotic cardiovascular and cerebrovascular diseases are the number one killer of human health. In view of the important role of mitochondria in the formation and evolution of atherosclerosis, our manuscript aims to comprehensively elaborate the relationship between mitochondria and the formation and evolution of atherosclerosis from the aspects of mitochondrial dynamics, mitochondria-organelle interaction (communication), mitochondria and cell death, mitochondria and vascular smooth muscle cell phenotypic switch, etc., which is combined with genome, transcriptome and proteome, in order to provide new ideas for the pathogenesis of atherosclerosis and the diagnosis and treatment of related diseases.

Effect of aortic smooth muscle BK channels on mediating chronic intermittent hypoxia-induced vascular dysfunction

Chronic intermittent hypoxia (CIH) can lead to vascular dysfunction and increase the risk of cardiovascular diseases, cerebrovascular diseases, and arterial diseases. Nevertheless, mechanisms underlying CIH-induced vascular dysfunction remain unclear. Herein, this study analyzed the role of aortic smooth muscle calciumactivated potassium (BK) channels in CIH-induced vascular dysfunction. CIH models were established in rats and rat aortic smooth muscle cells (RASMCs). Hemodynamic parameters such as mean blood pressure (MBP), diastolic blood pressure (DBP), and systolic blood pressure (SBP) were measured in rats, along with an assessment of vascular tone. NO and ET-1 levels were detected in rat serum, and the levels of ET-1, NO, eNOS, p-eNOS, oxidative stress markers (ROS and MDA), and inflammatory factors (IL-6 and TNF-α) were tested in aortic tissues. The Ca2+ concentration in RASMCs was investigated. The activity of BK channels (BKα and BKβ) was evaluated in aortic tissues and RASMCs. SBP, DBP, and MBP were elevated in CIH-treated rats, along with endothelial dysfunction, cellular edema and partial detachment of endothelial cells. BK channel activity was decreased in CIH-treated rats and RASMCs. BK channel activation increased eNOS, p-eNOS, and NO levels while lowering ET-1, ROS, MDA, IL-6, and TNF-α levels in CIH-treated rats. Ca2+ concentration increased in RASMCs following CIH modeling, which was reversed by BK channel activation. BK channel inhibitor (Iberiotoxin) exacerbated CIH-induced vascular disorders and endothelial dysfunction. BK channel activation promoted vasorelaxation while suppressing vascular endothelial dysfunction, inflammation, and oxidative stress, thereby indirectly improving CIH-induced vascular dysfunction.

circ_CSNK1E modulates airway smooth muscle cells proliferation and migration via miR-34a-5p/VAMP2 axis in asthma

BACKGROUND

Excessive proliferation and migration of airway smooth muscle cells (ASMCs) directly lead to airway remodeling in asthma. However, the role of circular RNAs (circRNAs) in airway remodeling remains unclear. This study aimed to investigate the regulatory role and mechanism of circ_CSNK1E in ASMCs proliferation and migration.

METHODS

In this study, RNA-sequencing was used to analyze cicRNAs expression in asthma samples. ASMCs were treated with 25 ng/mL PDGF-BB to establish a model of asthma in vitro. Then, we used RT-qPCR to assess circRNAs, microRNAs (miRNAs) and messenger RNAs (mRNAs) expression. Besides, CCK-8, colony formation, wound healing and transwell chamber assays were carried out to explore cell proliferation and migration. Subcellular localization assay was used to detect the location of circRNA. Next, bioinformatics, luciferase reporter and RIP assays were performed to evaluate the relationship among circ_CSNK1E, miRNA-34a-5p and VAMP2.

RESULTS

circ_CSNK1E expression was found to be significantly up-regulated in asthma samples and PDGF-BB-induced ASMCs. Functional experiments revealed that inhibition of circRNA_CSNK1E suppressed proliferation and migration of ASMCs stimulated by PDGF-BB. Next, we found that circRNA_CSNK1E served as a sponge for miR-34a-5p in ASMCs, and miR-34a-5p mimic suppressed proliferation and migration of ASMCs. Moreover, VAMP2 was confirmed as a direct target of miR-34a-5p. At last, inhibition of circRNA_CSNK1E suppressed proliferation and migration of ASMCs stimulated by PDGF-BB through miR-34a-5p/VAMP2 axis.

CONCLUSION

Collectively, these findings clarified the importance of circ_CSNK1E/miRNA-34a-5p/VAMP2 axis for the proliferation and migration of ASMCs. These indicated that inhibition of circ_CSNK1E might be a potential target for the treatment of airway remodeling in asthma.

Discovery of a Highly Selective β2-Adrenoceptor Agonist with a 2-Amino-2-phenylethanol Scaffold as an Oral Antiasthmatic Agent

Asthma patients in resource-poor countries cannot obtain adequate basic asthma medications because most asthma medications are supplied as inhalants. An alternative approach is to create oral antiasthmatic drugs with high β₂/β₁-selectivity, which should reduce treatment costs. In this study, we designed a cohort of compounds 1 using 2-(4-amino-3-chloro-5-(trifluoromethyl)phenyl)-2-(tert-butylamino)ethan-1-ol hydrogen chloride (1a) as the lead compound with an aim to expand the library of compounds possessing the 2-amino-2-phenylethanol scaffold. Structure-activity relationship studies on these compounds revealed that compounds created showed remarkable β₂ selectivity compared to isoproterenol and gave additional insights on the rational design of β₂-adrenoceptor agonists. Moreover, 1a was found as the best candidate compound showing the greatest potential for drug development. Cell-based assays showed that 1a was about 10 times more selective than salbutamol toward the β₂-adrenoceptor. Moreover, 1a exhibited good oral bioavailability and low acute oral toxicity. These data reveal 1a as an oral antiasthmatic agent.

Recent Advances in β2-Agonists for Treatment of Chronic Respiratory Diseases and Heart Failure

β₂-Adrenoceptor (β₂-AR) agonists are widely used as bronchodilators. The emerge of ultralong acting β₂-agonists is an important breakthrough in pulmonary medicine. In this review, we will provide mechanistic insights into the application of β₂-agonists in asthma, chronic obstructive pulmonary disease (COPD), and heart failure (HF). Recent studies in β-AR signal transduction have revealed opposing functions of the β₁-AR and the β₂-AR on cardiomyocyte survival. Thus, β₂-agonists and β-blockers in combination may represent a novel strategy for HF management. Allosteric modulation and biased agonism at the β₂-AR also provide a theoretical basis for developing drugs with novel mechanisms of action and pharmacological profiles. Overlap of COPD and HF presents a substantial clinical challenge but also a unique opportunity for evaluation of the cardiovascular safety of β₂-agonists. Further basic and clinical research along these lines can help us develop better drugs and innovative strategies for the management of these difficult-to-treat diseases.