Search Results (105)

Prolactin (PRL) is a hormone primarily associated with lactation, but it plays various roles in both men and women. PRL belongs to the family of peptide hormones, including placental lactogen and growth hormone. Interestingly, PRL is a pleiotropic hormone affecting several physiological and pathological conditions, including fertility. Moreover, several pathophysiological roles have been associated with this hormone, including those of the immune system, autoimmune disorders, asthma, and ageing. Additionally, PRL receptors are ubiquitously expressed in tissues, including the mammary gland, gonads, liver, kidney, adrenal gland, brain, heart, lungs, pituitary gland, uterus, skeletal muscle, skin blood cells, and immune system. Therefore, in the present paper, we cover the potential role that PRL may play in asthma by promoting inflammation and modulating immune responses. The detection of its receptor in lung tissue suggests a direct role in airway smooth muscle contractility through activation of signaling pathways such as JAK2-STAT5, MAPK/ERK1/2, and PI3K/Akt, as well as influencing ionic currents that regulate cell contraction, proliferation, and survival. In this sense, this review aims to explore the potential involvement of PRL in asthma pathophysiology by examining its interactions with intracellular signaling pathways and its possible impact on airway smooth muscle contractility and immune modulation. Full article

Background/Objectives: Asthma, a chronic airway inflammatory disease characterized by bronchial narrowing and caused by an inflammatory response, results in airway obstruction and hyperresponsiveness. Stachydrine (STA), an abundant metabolite found in plants and humans, is recognized for its bioactivity in treating fibrosis, cancer, and inflammation. However, its effects on asthma have not been fully elucidated. We aimed to investigate the ameliorating effects of STA on chronic airway inflammation caused by Dermatophagoides pteronyssinus (house dust mite, HDM). Methods: We used a murine model of HDM-induced airway inflammation to assess the change in metabolite profile by chronic airway inflammation. The mice were challenged with HDM (35 challenges in total) for up to 12 weeks. Serum metabolites were analyzed using capillary electrophoresis time-of-flight mass spectrometry. Results: HDM exposure increased airway hypersensitivity, immune cell infiltration, cytokine production, goblet cell hyperplasia, collagen deposition, and alpha smooth muscle actin and fibronectin expression. Serum metabolite analysis revealed that STA levels were lower in the mice with HDM-induced chronic inflammation than in the controls. In vitro analyses demonstrated that HDM sensitization increased cytokine production (interleukin [IL]-6 and IL-8) and extracellular signal-regulated kinase (ERK) activity. However, STA treatment reduced HDM-induced IL-6 and IL-8 production and ERK activity. Co-treatment with a mitogen-activated protein kinase (MAPK) inhibitor and STA resulted in a more pronounced reduction in cytokine production and MAPK activity. Conclusions: These findings suggest that STA, particularly when used in combination with a MAPK inhibitor, effectively suppresses airway inflammation through ERK pathway inhibition, making it a potential therapeutic agent for asthma treatment. Full article

Chronic obstructive pulmonary disease (COPD), whose main risk factor is cigarette smoking, is among the most prevalent diseases worldwide. Previous studies have shown that cigarette smoke extract (CSE) can directly affect pulmonary artery function independently of hypoxia resulting from the airway obstruction. In addition, CSE also affects bronchial smooth muscle, leading to airway hyper-responsiveness. However, its specific impact on the contractile machinery of this compartment remains unclear. In this study, using in vitro experiments with human bronchial smooth muscle cells (hBSMCs), we found that CSE exposure disrupted calcium homeostasis, increased ROS and lipid peroxidation, and reduced cell antioxidant defenses. Furthermore, CSE exposure altered the cell contractile apparatus by decreasing key cytoskeletal proteins and impairing actin dynamics, potentially contributing to the dysregulated contractile response of cells. Notably, these effects were significantly attenuated by antioxidant drugs such as mitoTEMPO and N-acetylcysteine, as well as by the inhibition of the endoplasmic reticulum (ER) calcium channels with 2-aminoethoxydiphenyl borate (2-APB). More importantly, mitoTEMPO partially restored the contractile response of bronchus upon CSE challenge. Collectively, our findings give evidence that CSE-mediated increase in ROS and intracellular calcium contribute to cytoskeletal disruption and functional impairment in airway smooth muscle. Moreover, these results also point to potential therapeutical approaches for mitigating the harmful effects of cigarette smoke in the lung. Full article

It has long been recognised that airway smooth muscle cells (ASMCs) possess an abundance of M2 muscarinic receptors (M2Rs). However, the contribution of postjunctional M2Rs to contractions of airway smooth muscle (ASM) induced by the release of acetylcholine (ACh) from parasympathetic nerves was thought to be minimal. Instead, it was believed that these responses were exclusively mediated by activation of M3Rs. However, evidence is emerging that postjunctional M2Rs may have a greater role than previously realised. In this review, we discuss ACh signalling in airways, highlighting the well-established autoinhibitory role of prejunctional M2Rs and the putative roles of postjunctional M2Rs to cholinergic contractions of ASM. The cellular mechanisms that underpin M2R-dependent contractions of ASM are reviewed, with a particular emphasis on the role of ion channels in these responses. The regulation of M2R signalling pathways by β-adrenoceptor activation is also considered, along with the potential involvement of postjunctional M2Rs in airway diseases such as asthma and chronic obstructive pulmonary disease (COPD). Full article

On-chip microfluidics are advanced in vitro models that simulate lung tissue’s native 3D environment more closely than static 2D models to investigate the complex lung architecture and multifactorial processes that lead to pulmonary disease. Current microfluidic systems can be restrictive in the quantities of biological sample that can be retrieved from a single micro-channel, such as RNA, protein, and supernatant. Here, we describe a newly developed large-scale airway-on-chip model that employs a surface area for a cell culture wider than that in currently available systems. This enables the collection of samples comparable in volume to traditional cell culture systems, making the device applicable to any workflow utilizing these static systems (RNA isolation, ELISA, etc.). With our construction method, this larger culture area allows for easier handling, the potential for a wide range of exposures, as well as the collection of low-quantity samples (e.g., volatiles or mitochondrial RNA). The model consists of two large polydimethylsiloxane (PDMS) cell culture chambers under an independent flow of medium or air, separated by a semi-permeable polyethylene (PET) cell culture membrane (23 μm thick, 0.4 μm pore size). Each chamber carries a 5 × 18 mm, 90 mm² (92 mm² with tapered chamber inlets) surface area that can contain up to 1–2 × 10⁴ adherent structural lung cells and can be utilized for close contact co-culture studies of different lung cell types, including airway epithelial cells, fibroblasts, smooth muscle cells, and endothelial cells. The parallel bi-chambered design of the chip allows for epithelial cells to be cultured at the air–liquid interface (ALI) and differentiation into a dense, multi-layered, pseudostratified epithelium under biological flow rates. This millifluidic airway-on-chip advances the field by providing a readily reproducible, easily adjustable, and cost-effective large-scale fluidic 3D airway cell culture platform. Full article

In severe asthma, symptoms are unstable despite intensive treatment based on high doses of inhaled corticosteroids and on-demand use of oral corticosteroids. Although, recently, various biological agents related to Th2 cytokines have been added to intensive controller medications for severe asthma, a significant progress has not been observed in the management for symptoms (dyspnea, wheezing and cough). Medical treatment focused on Type 2 inflammation is probably insufficient to maintain good long-term management for severe asthma. Airway eosinophilia and decreased reversibility in forced expiratory volume in 1 second (FEV₁) are listed as major predictors for exacerbation-prone asthma. However, it is generally considered that asthma is complex and heterogeneous. It is necessary to establish precision medicine using treatable traits based on a multidimensional approach related to asthma. Since phospholipids generate lysophospholipids and arachidonic acid by phospholipases, lysophospholipids can be associated with the pathogenesis of this disease via action on smooth muscle, endothelium, and epithelium in the airways. Lysophosphatidic acid (LPA), lysophosphatidylcholine (LPC), and sphingosine 1-phosphate (S1P) are increased in bronchoalveolar fluid after allergen challenge. LPA, LPC, and S1P recruit eosinophils to the lungs and cause β₂-adrenergic desensitization. LAP and S1P cause contraction and hyperresponsiveness in airway smooth muscle. Moreover, lysophosphatidylserine and S1P are associated with the allergic reaction related to IgE/FcεRI in mast cells. Lysophospholipid action is probably comprised of corticosteroid resistance and is independent of Type 2 inflammation, and may be corelated with oxidative stress. Lysophospholipids may be a novel molecular target in advancing the management and treatment of asthma. This review discusses the clinical relevance of lysophospholipids in asthma. Full article

Background: Chronic obstructive pulmonary disease (COPD) is characterized by progressive and incurable airflow obstruction and chronic inflammation. Both TGF-β1 and CXCL8 have been well described as fundamental to COPD progression. DNA methylation and histone acetylation, which are well-understood epigenetic mechanisms regulating gene expression, are associated with COPD progression. However, a deeper understanding of the complex mechanisms associated with DNA methylation, histone post-translational changes and RNA methylation in the context of regulatory pathways remains to be elucidated. We here report on how DNA methylation and histone acetylation inhibition differentially affect CXCL8 signaling in primary human non-COPD and COPD airway cells. Methods: Airway smooth muscle (ASM) cells, a pivotal cell type in COPD, were isolated from the small airways of heavy smokers with and without COPD. Histone acetylation and DNA methylation were inhibited before the TGF-β1 stimulation of cells. Subsequently, CXCL8 production and the abundance and activation of pertinent transcription regulatory proteins (NF-κB, p38 MAPK and JNK) were analyzed. Results: TGF-β1-stimulated CXCL8 release from ASM cells from ‘healthy’ smoker subjects was significantly modulated by DNA methylation (56.32 pg/mL and 56.60 pg/mL) and acetylation inhibitors (27.50 pg/mL and 48.85 pg/mL) at 24 and 48 h, respectively. However, modulation via the inhibition of DNA methylation (34.06 pg/mL and 43.18 pg/mL) and acetylation (23.14 pg/mL and 27.18 pg/mL) was observed to a lesser extent in COPD ASM cells. These changes were associated with differences in the TGF-β1 activation of NF-κB and MAPK pathways at 10 and 20 min. Conclusions: Our findings offer insight into differential epigenetics in controlling COPD ASM cells and provide a foundation warranting future studies on epigenetic differences associated with COPD diagnosis. This would provide a scope for developing therapeutic interventions targeting signaling and epigenetic pathways to improve patient outcomes. Full article

Despite the significant progress in diagnostic and therapeutic strategies, vascular diseases, such as cardiovascular diseases (CVDs) and respiratory diseases, still cannot be successfully eliminated. Vascular cells play a key role in maintaining vascular homeostasis. Notably, a variety of cells produce and secrete platelet-derived growth factors (PDGFs), which promote mitosis and induce the division, proliferation, and migration of vascular cells including vascular smooth muscle cells (SMCs), aortic SMCs, endothelial cells, and airway SMCs. Therefore, PDGF/PDGR receptor signaling pathways play vital roles in regulating the homeostasis of blood vessels and the onset and development of CVDs, such as atherosclerosis, and respiratory diseases including asthma and pulmonary arterial hypertension. Recently, accumulating evidence has demonstrated that microRNA, long-chain non-coding RNA, and circular RNA are involved in the regulation of PDGF/PDGFR signaling pathways through competitive interactions with target mRNAs, contributing to the occurrence and development of the above-mentioned diseases. These novel findings are useful for laboratory research and clinical studies. The aim of this article is to conclude the recent progresses in this field, particular the mechanisms of action of these non-coding RNAs in regulating vascular remodeling, providing potential strategies for the diagnosis, prevention, and treatment of vascular-dysfunction-related diseases, particularly CVDs and respiratory diseases. Full article

Severe asthma is characterized by increased cell volume (hypertrophy) and enhanced contractile function (hyperresponsiveness) of the airway smooth muscle cells (ASMCs). The causative relationship and underlying regulatory mechanisms between them, however, have remained unclear. Here, we manipulated the single-cell volume of in vitro cultured human ASMCs to increase from 2.7 to 5.2 and 8.2 × 10³ μm³ as a simulated ASMC hypertrophy by culturing the cells on micropatterned rectangular substrates with a width of 25 μm and length from 50 to 100 and 200 μm, respectively. We found that as the cell volume increased, ASMCs exhibited a pro-contractile function with increased mRNA expression of contractile proteins, increased cell stiffness and traction force, and enhanced response to contractile stimulation. We also uncovered a concomitant increase in membrane tension and Piezo1 mRNA expression with increasing cell volume. Perhaps more importantly, we found that the enhanced contractile function due to cell volume increase was largely attenuated when membrane tension and Piezo1 mRNA expression were downregulated, and an auto-regulatory loop between Piezo1 and YAP mRNA expression was also involved in perpetuating the contractile function. These findings, thus, provide convincing evidence of a direct link between hypertrophy and enhanced contractile function of ASMCs that was mediated via Piezo1 mRNA expression, which may be specifically targeted as a novel therapeutic strategy to treat pulmonary diseases associated with ASMC hypertrophy such as severe asthma. Full article

Background/Objective: Sensitization to specific IgE Staphylococcus aureus enterotoxins (SEs) is associated with an increased risk for severe asthma development. Limited data exist regarding the association of seropositivity for specific IgE SEs and the different aspects of severe asthma. We aimed to determine whether the presence of SEs is associated with asthma-related parameters such as inflammatory cells in the airways, features of airway remodeling, and other variables relating to asthma assessment and severity. Methods: Fifty patients with severe asthma were recruited in the study. Demographics, comorbidities, asthma duration, and asthma medication were recorded by treating physicians. Specific IgE SE measurement, lung function, atopic status, asthma control test (ACT), sputum induction, bronchoscopy with BAL, and indices of airway remodeling were also assessed. Results: Twelve patients were positive to enterotoxin sensitization. Patients seropositive to specific IgE SEs significantly differed in regard to FEV₁% pred and FEV₁/FVC ratio compared to seronegative ones. Analyzing the inflammatory variables obtained from induced sputum, BAL, and endobronchial biopsies, the only significant difference was that of smooth muscle area (SMA), which was greater in specific IgE SE seropositive patients. The multivariate linear regression analysis showed two significant associations of specific IgE SE seropositivity. We found a negative with FEV₁% pred with beta standardized coefficient 95%CI −0.054 (−0.083, −0.031), p < 0.001, and a positive with SMA with beta standardized coefficient 95%CI 0.054 (0.081, 0.037), p < 0.001. Conclusions: Seropositivity to specific IgE SEs in severe asthma is associated with more severe airflow limitation, obstruction, and upregulation in SMA, indicating a possible role in the remodeling process. Full article

Exposure to particulate matter (PM), especially PM_2.5, is known to exacerbate asthma, posing a significant public health risk. This study investigated the asthma-reducing effects of photobiomodulation (PBM) in a mice model mimicking allergic airway inflammation exacerbated by PM_2.5 exposure. The mice received sensitization with ovalbumin (OVA) and were subsequently treated with PM_2.5 at a dose of 0.1 mg/kg every 3 days, for 9 times over 3 weeks during the challenge. PBM, using a 610 nm wavelength LED, was applied at 1.7 mW/cm² to the respiratory tract via direct skin contact for 20 min daily for 19 days. Results showed that PBM significantly reduced airway hyperresponsiveness, plasma immunoglobulin E (IgE) and OVA-specific IgE, airway inflammation, T-helper type 2 cytokine, histamine and tryptase in bronchoalveolar lavage fluid (BALF), and goblet cell hyperplasia in PM_2.5-exposed asthmatic mice. Moreover, PBM alleviated subepithelial fibrosis by reducing collagen deposition, airway smooth muscle mass, and expression of fibrosis-related genes. It mitigated reactive oxygen species generation, oxidative stress, endoplasmic reticulum stress, apoptotic cell death, ferroptosis, and modulated autophagic signals in the asthmatic mice exposed to PM_2.5. These findings suggest that PBM could be a promising intervention for PM_2.5-induced respiratory complications in patients with allergic asthma. Full article

Bitter taste receptors (TAS2Rs) expressed in extraoral tissues represent a whole-body sensory system, whose role and mechanisms could be of interest for the identification of new therapeutic targets. It is known that TAS2R46s in pre-contracted airway smooth muscle cells increase mitochondrial calcium uptake, leading to bronchodilation, and that several SNPs have been identified in its gene sequence. There are very few reports on the structure–function analysis of TAS2Rs. Thus, we delved into the subject by using mutagenesis and in silico studies. We generated a cellular model that expresses native TAS2R46 to evaluate the influence of the four most common SNPs on calcium fluxes following the activation of the receptor by its specific ligand absinthin. Then, docking studies were conducted to correlate the calcium flux results to the structural mutation. The analysed SNPs differently modulate the TAS2R46 signal cascade according to the altered protein domain. In particular, the SNP in the sixth transmembrane domain of the receptors did not modulate calcium homeostasis, while the SNPs in the sequence coding for the fourth transmembrane domain completely abolished the mitochondrial calcium uptake. In conclusion, these results indicate the fourth transmembrane domain of TAS2R46 is critical for the intrinsic receptor activity. Full article

Background: Tocotrienols exhibit antioxidant and anti-inflammatory activities. RhoA, a small GTPase protein, plays a crucial role in regulating contractility in airway smooth muscle (ASM). Previous studies have demonstrated that γ-tocotrienols reduce ASM proliferation and migration by inhibiting the activation of RhoA. In this present study, we investigate the effect of another vitamin E isoform, β-tocotrienols, on human ASM cell proliferation and migration stimulated by platelet-derived growth factor-BB (PDGF-BB). Methods: Human ASM cells were pre-treated with β-tocotrienol prior to being stimulated with PDGF-BB to induce ASM cell proliferation and migration. The proliferation and migration of PDGF-BB-induced human ASM cells were assessed using colorimetric and transwell migration assays. The intracellular ROS assay kit was employed to quantify reactive oxygen species (ROS) in human ASM cells. Additionally, we explored the effect of β-tocotrienols on the signaling pathways involved in PDGF-BB-induced ASM proliferation and migration. Results: β-tocotrienol inhibited PDGF-BB-induced ASM cell proliferation and migration by reducing RhoA activation and ROS production. However, in this present study, β-tocotrienol did not affect the signaling pathways associated with cyclin D1, phosphorylated Akt1, and ERK1/2. Conclusions: In conclusion, the inhibition of RhoA activation and ROS production by β-tocotrienol, resulting in the reduction in human ASM proliferation and migration, suggests its potential as a treatment for asthma airway remodeling. Full article

Cell-to-cell distant mechanical communication has been demonstrated using in vitro and in vivo models. However, the molecular mechanisms underlying long-range cell mechanoresponsive interactions remain to be fully elucidated. This study further examined the roles of α-Catenin and Piezo1 in traction force-induced rapid branch assembly of airway smooth muscle (ASM) cells on a Matrigel hydrogel containing type I collagen. Our findings demonstrated that siRNA-mediated downregulation of α-Catenin or Piezo1 expression or chemical inhibition of Piezo1 activity significantly reduced both directional cell movement and branch assembly. Regarding the role of N-cadherin in regulating branch assembly but not directional migration, our results further confirmed that siRNA-mediated downregulation of α-Catenin expression caused a marked reduction in focal adhesion formation, as assessed by focal Paxillin and Integrin α5 localization. These observations imply that mechanosensitive α-Catenin is involved in both cell–cell and cell-matrix adhesions. Additionally, Piezo1 partially localized in focal adhesions, which was inhibited by siRNA-mediated downregulation of α-Catenin expression. This result provides insights into the Piezo1-mediated mechanosensing of traction force on a hydrogel. Collectively, our findings highlight the significance of α-Catenin in the regulation of cell-matrix interactions and provide a possible interpretation of Piezo1-mediated mechanosensing activity at focal adhesions during cell–cell mechanical communication. Full article

The Cupressaceae family includes species considered to be medicinal. Their essential oil is used for headaches, colds, cough, and bronchitis. Cedar trees like Chamaecyparis lawsoniana (C. lawsoniana) are commonly found in urban areas. We investigated whether C. lawsoniana exerts some of its effects by modifying airway smooth muscle (ASM) contractility. The leaves of C. lawsoniana (363 g) were pulverized mechanically, and extracts were obtained by successive maceration 1:10 (w:w) with methanol/CHCl₃. Guinea pig tracheal rings were contracted with KCl, tetraethylammonium (TEA), histamine (HIS), or carbachol (Cch) in organ baths. In the Cch experiments, tissues were pre-incubated with D-600, an antagonist of L-type voltage-dependent Ca²⁺ channels (L-VDCC) before the addition of C. lawsoniana. Interestingly, at different concentrations, C. lawsoniana diminished the tracheal contractions induced by KCl, TEA, HIS, and Cch. In ASM cells, C. lawsoniana significantly diminished L-type Ca²⁺ currents. ASM cells stimulated with Cch produced a transient Ca²⁺ peak followed by a sustained plateau maintained by L-VDCC and store-operated Ca²⁺ channels (SOCC). C. lawsoniana almost abolished this last response. These results show that C. lawsoniana, and its active metabolite quercetin, relax the ASM by inhibiting the L-VDCC and SOCC; further studies must be performed to obtain the complete set of metabolites of the extract and study at length their pharmacological properties. Full article