Borneol inhibits CD4 + T cells proliferation by down-regulating miR-26a and miR-142-3p to attenuate asthma

MicroRNA-26a in respiratory diseases: mechanisms and therapeutic potential

MicroRNAs (miRNAs) are short, non-coding single-stranded RNA molecules approximately 22 nucleotides in length, intricately involved in post-transcriptional gene expression regulation. Over recent years, researchers have focused keenly on miRNAs, delving into their mechanisms in various diseases such as cancers. Among these, miR-26a emerges as a pivotal player in respiratory ailments such as pneumonia, idiopathic pulmonary fibrosis, lung cancer, asthma, and chronic obstructive pulmonary disease. Studies have underscored the significance of miR-26a in the pathogenesis and progression of respiratory diseases, positioning it as a promising therapeutic target. Nevertheless, several challenges persist in devising medical strategies for clinical trials involving miR-26a. In this review, we summarize the regulatory role and significance of miR-26a in respiratory diseases, and we analyze and elucidate the challenges related to miR-26a druggability, encompassing issues such as the efficiency of miR-26a, delivery, RNA modification, off-target effects, and the envisioned therapeutic potential of miR-26a in clinical settings.

Formaldehyde aggravates airway inflammation through induction of glycolysis in an experimental model of asthma exacerbated by lipopolysaccharide

Formaldehyde (FA) exposure has been reported to induce or aggravate allergic asthma. Infection is also a potential risk factor for the onset and aggravation of asthma. However, no study has addressed the effects of FA exposure on asthmatic patients with respiratory infection. FA is ubiquitous in environment and respiratory infections are common in clinics. Therefore, it is necessary to explore whether FA exposure leads to the further worsening of symptoms in asthma patients with existing respiratory infection. In the present study, ovalbumin (OVA) was used to establish the murine asthma model. Lipopolysaccharide (LPS) was intratracheal administrated to mimic asthma with respiratory infection. The mice were exposed to 0.5 mg/m3 FA. FA exposure did not induce a significant aggravation on OVA induced allergic asthma. However, the lung function of specific airway resistance (sRaw), histological changes and cytokines production were greatly aggravated by FA exposure in OVA/LPS induced murine asthma model. Monocyte-derived macrophages (MDMs) were isolated from asthmatic patients. Exposure of MDMs to FA and LPS resulted in increased TNF-α, IL-6, IL-1β, and nitric oxide (NO) production. Lactate produciton and lactate dehydrogenase A (LDHA) expression were found to be upregulated by FA in OVA/LPS induced asthmatic mice and LPS stimulated MDMs. Furthermore, glycolysis inhibitor 2-Deoxy-d-glucose attenuated FA and LPS induced TNF-α, IL-6, IL-1β, and NO production. We conclude that FA exposure can lead to the aggravation of allergic asthma with infection through induction of glycolysis. This study could offer some new insight into how FA promotes asthma development.

Multistep Approach Points to Compounds Responsible for the Biological Activity and Safety of Hydrolates from Nine Lamiaceae Medicinal Plants on Human Skin Fibroblasts

As byproducts of essential oil distillation, hydrolates are used in natural cosmetics/biomedicine due to their beneficial skin effects. However, data on their safety with relevant biological targets, such as human skin cells, are scarce. Therefore, we have tested nine hydrolates from the Lamiaceae family with skin fibroblasts that are responsible for extracellular collagenous matrix builds. Thyme, oregano, and winter savoury hydrolates showed several times higher total phenolics, which correlated strongly with their radical scavenging and antioxidative capacity; there was no correlation between their viability profiles and the reducing sugar levels. No proteins/peptides were detected. All hydrolates appeared safe for prolonged skin exposure except for 10-fold diluted lavender, which showed cytotoxicity (~20%), as well as rosemary and lavandin (~10%) using viability, DNA synthesis, and cell count testing. Clary sage, oregano, lemon balm, and thyme hydrolates (10-fold diluted) increased fibroblast viability and/or proliferation by 10-30% compared with the control, while their viability remained unaffected by Mentha and winter savoury. In line with the STITCH database, increased viability could be attributed to thymol presence in oregano and thyme hydrolates in lemon balm, which is most likely attributable to neral and geranial. The proliferative effect of clary sage could be supported by alpha-terpineol, not linalool. The major volatile organic compounds (VOCs) associated with cytotoxic effects on fibroblasts were borneol, 1,8-cineole, and terpinene-4-ol. Further research with pure compounds is warranted to confirm the roles of VOCs in the observed effects that are relevant to cosmetic and wound healing aspects.

Modern drug discovery using ethnobotany: A large-scale cross-cultural analysis of traditional medicine reveals common therapeutic uses

For millennia, numerous cultures and civilizations have relied on traditional remedies derived from plants to treat a wide range of conditions and ailments. Here, we systematically analyzed ethnobotanical patterns across taxonomically related plants, demonstrating that congeneric medicinal plants are more likely to be used for treating similar indications. Next, we reconstructed the phytochemical space covered by medicinal plants to reveal that (i) taxonomically related medicinal plants cover a similar phytochemical space, and (ii) chemical similarity correlates with similar therapeutic usage. Lastly, we present several case scenarios illustrating how mining this information can be used for drug discovery applications, including: (i) investigating taxonomic hotspots around particular indications, (ii) exploring shared patterns of congeneric plants located in different geographic areas, but which have been used to treat the same indications, and (iii) showing the concordance between ethnobotanical patterns among non-taxonomically related plants and the presence of shared bioactive phytochemicals.

The history, stereochemistry, ethnopharmacology and quality assessment of borneol

ETHNOPHARMACOLOGICAL RELEVANCE

Borneol (BO) represents a global trade-driven spreading of ethnic medicine traceable to the classical age, and won its name specific to its original habitat "Borneo". BO shows broad spectral pharmacological effects, such as anti-inflammatory, analgesic, antipyretic, inducing resuscitation, and widely applied in the protection and treatment of cardiovascular and cerebrovascular diseases, used singly or mostly in compound formulae.

AIM OF THE STUDY

Three stereoscopic configuration forms of BO, l-borneol (LB), d-borneol (DB), and dl-borneol (synthetic, SB), are formulated in broad spectral application, yet their diverse pharmacodynamic and pharmacokinetic properties caused by configurations, and accurate assay and quality assessment are often overlooked. A systematic review and analysis of lumped studies and applications is necessary to clarify the relationship between configuration and its original plant, analysis method, activity and side effect BO in order to guarantee the efficacy and safety during their application.

MATERIALS AND METHODS

The public databases including PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure were referenced to summarize a comprehensive research and application data of BO published up to date.

RESULTS

This review includes following sections: History and current status, Stereochemistry, Ethnopharmacology, and Quality assessment. In the section of history, the changes of the plant origins of the two isomeric forms of natural BO were described respectively, and the methods for synthetic racemate SB were also included. The section of stereochemistry deals with the stereoscopic structures, physical/chemical property, optical rotation of the three forms of BO, as well as the main related substances like isoborneol, obtained in SB via chemical transformation of camphor and turpentine oil. In the section of Ethnopharmacology, pharmacological activities and pharmacokinetics of different forms of BO were discussed. BO is usually used as an "adjuvant", by enhancing the permeability of the blood-brain barrier and intervene the ADME/T pathways of the other ingredients in the same formulation. In the section of quality assessment, the analytical methods, including chromatography, especially GC, and spectroscopy were addressed on the chiral separation of the coexisting enantiomers.

CONCLUSIONS

This overview systematically summarized three forms of BO in terms of history, stereochemistry, ethnopharmacology, and quality assessment, which, hopefully, can provide valuable information and strategy for more reasonable application and development of the globally reputed ethnic medicine borneol with characteristics in stereochemistry.

MiR-506 targets polypyrimidine tract-binding protein 1 to inhibit airway inflammatory response and remodeling via mediating Wnt/β-catenin signaling pathway

BACKGROUND

Airway remodeling, which contributes to the clinical course of childhood asthma, occurs due to airway inflammation and is featured by anomalous biological behaviors of airway smooth muscle cells (ASMCs). microRNA (miRNA) plays an essential role in the etiopathogenesis of asthma.

OBJECTIVE

This research was aimed to characterize miR-506 in asthma and uncover potential regulatory machinery.

MATERIAL AND METHODS

The asthmatic cell model was established by treating ASMCs with transforming growth factor-beta1 (TGF-β1) and assessed by the levels of interleukin (IL)-1β and interferon gamma (IFN-γ). Using real-time quantitative polymerase chain reaction, mRNA expression of miR-506 and polypyrimidine tract-binding protein 1 (PTBP1) was measured. Cell counting kit-8 and Transwell migration tests were used for estimating the capacity of ASMCs to proliferate and migrate. Luciferase reporter assay was used to corroborate whether miR-506 was directly bound to PTBP1. Expression of PTBP1, collagen I and III, and essential proteins of the wingless-related integration (Wnt)/β-catenin pathway (β-catenin, c-MYC and cyclin D1) was accomplished by Western blot analysis. The involvement of Wnt/β-catenin signaling in asthma was confirmed by Wnt signaling pathway inhibitor (IWR-1).

RESULTS

miR-506 was poorly expressed in asthmatic tissues and cell model. Functionally, overexpression of miR-506 reduced aberrant proliferation, migration, inflammation and collagen deposition of ASMCs triggered by TGF-β1. Mechanically, miR-506 directly targeted the 3' untranslated region (3-UTR) of PTBP1 and had a negative regulation on PTBP1 expression. Moreover, overexpression of miR-506 suppressed the induction of Wnt/β-catenin pathway. The administration of IWR-1 further validated negative correlation between miR-506 and the Wnt/β-catenin pathway in asthma.

CONCLUSION

Our data indicated that targeting miR-506/PTBP1/Wnt/β-catenin axis might point in a helpful direction for treating asthma in children.

Recent miRNA Research in Asthma

PURPOSE OF REVIEW

The study of microRNA in asthma has revealed a vibrant new level of gene regulation underlying asthma pathology. Several miRNAs have been shown to be important in asthma, influencing various biological mechanisms which lead to asthma pathology and symptoms. In addition, miRNAs have been proposed as biomarkers of asthma affection status, asthma severity, and asthma treatment response. We review all recent asthma-miRNA work, while also presenting comprehensive tables of all miRNA results related to asthma.

RECENT FINDINGS

We here reviewed 63 recent studies published reporting asthma and miRNA research, and an additional 14 reviews of the same. We summarized the information for both adult and childhood asthma, as well as research on miRNAs in asthma-COPD overlap syndrome (ACOs), and virus-induced asthma exacerbations. We attempted to present a comprehensive collection of recently published asthma-associated miRNAs as well as tables of all published asthma-related miRNA results.

Neutrophil Immunomodulatory Activity of (−)-Borneol, a Major Component of Essential Oils Extracted from Grindelia squarrosa

Grindelia squarrosa (Pursh) Dunal is used in traditional medicine for treating various diseases; however, little is known about the immunomodulatory activity of essential oils from this plant. Thus, we isolated essential oils from the flowers (GEO_Fl) and leaves (GEO_Lv) of G. squarrosa and evaluated the chemical composition and innate immunomodulatory activity of these essential oils. Compositional analysis of these essential oils revealed that the main components were α-pinene (24.7 and 23.2% in GEO_Fl and GEO_Lv, respectively), limonene (10.0 and 14.7%), borneol (23.4 and 16.6%), p-cymen-8-ol (6.1 and 5.8%), β-pinene (4.0 and 3.8%), bornyl acetate (3.0 and 5.1%), trans-pinocarveol (4.2 and 3.7%), spathulenol (3.0 and 2.0%), myrtenol (2.5 and 1.7%), and terpinolene (1.7 and 2.0%). Enantiomer analysis showed that α-pinene, β-pinene, and borneol were present primarily as (−)-enantiomers (100% enantiomeric excess (ee) for (−)-α-pinene and (−)-borneol in both GEO_Fl and GEO_Lv; 82 and 78% ee for (−)-β-pinene in GEO_Fl and GEO_Lv), while limonene was present primarily as the (+)-enantiomer (94 and 96 ee in GEO_Fl and GEO_Lv). Grindelia essential oils activated human neutrophils, resulting in increased [Ca²⁺]_i (EC₅₀ = 22.3 µg/mL for GEO_Fl and 19.4 µg/mL for GEO_Lv). In addition, one of the major enantiomeric components, (−)-borneol, activated human neutrophil [Ca²⁺]_i (EC₅₀ = 28.7 ± 2.6), whereas (+)-borneol was inactive. Since these treatments activated neutrophils, we also evaluated if they were able to down-regulate neutrophil responses to subsequent agonist activation and found that treatment with Grindelia essential oils inhibited activation of these cells by the N-formyl peptide receptor 1 (FPR1) agonist fMLF and the FPR2 agonist WKYMVM. Likewise, (−)-borneol inhibited FPR-agonist-induced Ca²⁺ influx in neutrophils. Grindelia leaf and flower essential oils, as well as (−)-borneol, also inhibited fMLF-induced chemotaxis of human neutrophils (IC₅₀ = 4.1 ± 0.8 µg/mL, 5.0 ± 1.6 µg/mL, and 5.8 ± 1.4 µM, respectively). Thus, we identified (−)-borneol as a novel modulator of human neutrophil function.

PTEN: An Emerging Potential Target for Therapeutic Intervention in Respiratory Diseases

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a potent tumor suppressor that regulates several key cellular processes, including proliferation, survival, genomic integrity, migration, and invasion, via PI3K-dependent and independent mechanisms. A subtle decrease in PTEN levels or catalytic activity is implicated not only in cancer but also in a wide spectrum of other diseases, including various respiratory diseases. A systemic overview of the advances in the molecular and cellular mechanisms of PTEN involved in the initiation and progression of respiratory diseases may offer novel targets for the development of effective therapeutics for the treatment of respiratory diseases. In the present review, we highlight the novel findings emerging from current research on the role of PTEN expression and regulation in airway pathological conditions such as asthma/allergic airway inflammation, pulmonary hypertension (PAH), chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and other acute lung injuries (ALI). Moreover, we discuss the clinical implications of PTEN alteration and recently suggested therapeutic possibilities for restoration of PTEN expression and function in respiratory diseases.

Potentiation of the Activity of Antibiotics against ATCC and MDR Bacterial Strains with (+)-α-Pinene and (-)-Borneol

The increasing rates of antimicrobial resistance have demanded the development of new drugs as conventional antibiotics have become significantly less effective. Evidence has identified a variety of phytocompounds with the potential to be used in the combat of infections caused by multidrug-resistant (MDR) bacteria. Considering the verification that terpenes are promising antibacterial compounds, the present research aimed to evaluate the antibacterial and antibiotic-modulating activity of (+)-α-pinene and (-)-borneol against MDR bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the compounds and antibiotics and further evaluate the intrinsic and associated antibiotic activity. These analyses revealed that (+)-α-pinene showed significant antibacterial activity only against E. coli (MIC = 512 μg.mL⁻¹), while no significant inhibition of S. aureus and P. aeruginosa growth was observed (MIC ≥ 1024 μg mL⁻¹). However, when combined with antibiotics, this compound induced a significant improvement in the activity of conventional antibiotics, as observed for ciprofloxacin, amikacin, and gentamicin against Staphylococcus aureus, as well as for amikacin and gentamicin against Escherichia coli, and amikacin against Pseudomonas aeruginosa. On the other hand, (-)-borneol was found to inhibit the growth of E. coli and enhance the antibiotic activity of ciprofloxacin and gentamicin against S. aureus. The present findings indicate that (+)-α-pinene and (-)-borneol are phytocompounds with the potential to be used in the combat of antibacterial resistance.

MicroRNA-98-5p Inhibits IL-13-Induced Proliferation and Migration of Human Airway Smooth Muscle Cells by Targeting RAC1

The dysfunction of airway smooth muscle cells (ASMCs) is one of the key factors in the pathogenesis of asthma. How miR-98-5p works in asthma has not been completely elucidated. This work focused on how miR-98-5p functions in the proliferation and migration of human ASMCs treated with interleukin-13 (IL-13). MiR-98-5p expression in plasma of asthmatic patients and IL-13-stimulated ASMCs was probed by quantitative real-time polymerase chain reaction (qRT-PCR). RAS-relevant C3 botulinum toxin substrate 1 (RAC1) protein expression in ASMCs was assessed by Western blot. The growth of ASMCs was measured by cell counting kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. The migration of ASMCs was examined by Transwell assay. Besides, the apoptosis of ASMCs was analyzed by flow cytometry. The targeting relationship between miR-98-5p and RAC1 3'-UTR was verified by a dual-luciferase reporter gene assay. MiR-98-5p expression was reduced in patients' plasma and IL-13-stimulated ASMCs, and RAC1 expression was upregulated in ASMCs treated with IL-13. MiR-98-5p overexpression inhibited IL-13-induced proliferation and migration of ASMCs while promoting the apoptosis. The opposite result was observed after inhibiting miR-98-5p expression. Besides, RAC1 was identified as a direct downstream target of miR-98-5p in ASMCs. The restoration of RAC1 expression counteracted the impacts of miR-98-5p overexpression on IL-13-stimulated proliferation, migration, and apoptosis of ASMCs. MiR-98-5p inhibits IL-13-induced proliferation and migration and accelerates the apoptosis of ASMCs by downregulating RAC1 expression.