Molecular and cellular pruritus mechanisms in the host skin.

Pruritus, also known as itching, is a complex sensation that involves the activation of specific physiological and cellular receptors. The skin is innervated with sensory nerves as well as some receptors for various sensations, and its immune system has prominent neurological connections. Sensory neurons have a considerable impact on the sensation of itching. However, immune cells also play a role in this process, as they release pruritogens. Disruption of the dermal barrier activates an immune response, initiating a series of chemical, physical, and cellular reactions. These reactions involve various cell types, including keratinocytes, as well as immune cells involved in innate and adaptive immunity. Collective activation of these immune responses confers protection against potential pathogens. Thus, understanding the molecular and cellular mechanisms that contribute to pruritus in host skin is crucial for the advancement of effective treatment approaches. This review provides a comprehensive analysis of the present knowledge concerning the molecular and cellular mechanisms underlying itching signaling in the skin. Additionally, this review explored the integration of these mechanisms with the broader context of itch mediators and the expression of their receptors in the skin.

miR-128-3p alleviates airway inflammation in asthma by targeting SIX1 to regulate mitochondrial fission and fusion.

Bronchial asthma is known for airway inflammation, hyperresponsiveness, and remodeling.MicroRNAs (MiRNAs) have been involved in the development of asthma, whereas, the mechanism of various MiRNAs in asthma remains to be elucidated. In this study, we aim to explore the mechanism of miR-128-3p in asthma-related airway inflammation by targeting sine oculis homeobox homolog 1 (SIX1) to regulate the mitochondrial function. In an ovalbumin (OVA) asthma mouse model, miR-128-3p levels were found to be significantly diminished. Administration of miR-128-3p agomir decreased peribronchial inflammatory cell infiltration and improved airway inflammation. Afterwards, we used the luciferase reporter assay to predict and confirmed that SIX1 is a target gene of miR-128-3p. Overexpression of miR-128-3p attenuated IL-13-induced cellular inflammation and ROS production in bronchial epithelial cells (BEAS-2B). In vitro, overexpression of miR-128-3p and SIX1 knockdown mitigated mitochondrial fragmentation, reduced Drp1-mediated mitochondrial division, and upregulated mitochondrial membrane potential. Moreover, led to decreased production of ROS/mitochondrial ROS, P-Drp1(616) and Fis1 expression, while enhancing P-Drp1(637), MFN1, caspase-3/9, and Bax-mediated apoptosis. Our findings demonstrated that miR-128-3p could alleviate airway inflammation by downregulating SIX1 and improving mitochondrial function, positioning the miR-128-3p/SIX1/Drp1 signaling as a potential therapeutic target for asthma.

IL-4 activates ULK1/Atg9a/Rab9 in asthma, NLRP3 inflammasomes, and Golgi fragmentation by increasing autophagy flux and mitochondrial oxidative stress.

During asthma, there is an intensification of pulmonary epithelial inflammation, mitochondrial oxidative stress, and Golgi apparatus fragmentation. However, the underlying mechanism remains largely unknown. Therefore, this study investigated the roles of ULK1, Atg9a, and Rab9 in epithelial inflammation, mitochondrial oxidative stress, and Golgi apparatus fragmentation. We found that ULK1 gene knockout reduced the infiltration of inflammatory cells, restored the imbalance of the Th1/Th2 ratio, and inhibited the formation of inflammatory bodies in the lung tissue of house dust mite-induced asthma mice. Moreover, we demonstrated that Atg9a interacted with ULK1 at S467. ULK1 phosphorylated Atg9a at S14. Treatment with ULK1 activator (LYN-1604) and ULK1 inhibitor (ULK-101) respectively promoted and inhibited inflammasome activation, indicating that the activation of inflammasome induced by house dust mite in asthma mice is dependent on ULK1. For validation of the in vivo results, we then used a lentivirus containing ULK1 wild type and ULK1-S467A genes to infect Beas-2b-ULK1-knockout cells and establish a stable cell line. The results suggest that the ULK1 S467 site is crucial for IL-4-induced inflammation and oxidative stress. Experimental verification confirmed that Atg9a was the superior signaling pathway of Rab9. Interestingly, we found for the first time that Rab9 played a very important role in inflammation-induced fragmentation of the Golgi apparatus. Inhibiting the activation of the ULK1/Atg9a/Rab9 signaling pathways can inhibit Golgi apparatus fragmentation and mitochondrial oxidative stress in asthma while reducing the production of NLRP3-mediated pulmonary epithelial inflammation.

A single fluorescent probe to examine the dynamics of mitochondria-lysosome interplay and extracellular vesicle role in ferroptosis.

Ferroptosis is a non-apoptotic form of cell death characterized by iron-dependent lipid peroxidation and glutathione (GSH) depletion. Despite recent advances, challenges remain in understanding the bidirectional interactions or interplay between organelles during ferroptosis. In this study, we aimed to understand the interplay between mitochondria (Mito) and lysosomes (Lyso) in cell homeostasis and ferroptosis. For this purpose, we designed a single fluorescent probe that marks GSH in Mito and hypochlorous acid (HOCl) in Lyso with two distinct emissions. Using this dual-targeted single fluorescent probe (9-morphorino pyronine), we detected Mito-Lyso interplay in ferroptosis. We disclosed differences in Mito-Lyso interplay depending on the induction of ferroptosis. Although erastin treatment decreased GSH, RSL3 triggered a HOCl burst, and FIN56- and FINO2-induced ferroptosis increased GSH and HOCl. Additionally, we showed that only extracellular vesicles generated during erastin-induced ferroptosis could spontaneously move and dock to neighboring cells, resulting in accelerated cell death.

JTE-013 Alleviates Pulmonary Fibrosis by Affecting the RhoA/YAP Pathway and Mitochondrial Fusion/Fission.

Pulmonary fibrosis may be due to the proliferation of fibroblasts and the aggregation of extracellular matrix, resulting in the stimulation of inflammation damage, destroying lung tissue structure, seriously affecting the patient's respiratory function, and even leading to death. We investigated the role and mechanism of JTE-013 in attenuating bleomycin (BLM)-induced pulmonary fibrosis. BLM-induced pulmonary fibrosis was established in mice. Type 2 alveolar epithelial cells (MLE-12) were stimulated with sphingosine monophosphate (S1P) in vitro. JTE-013, an S1PR2 (sphingosine 1-phosphate receptor 2) antagonist, and Verteporfin were administered in vivo and in vitro. IL-4, IL-5, TNF-α, and IFN-γ were measured by ELISA. IL-4 and IFN-γ positive cells were detected by flow cytometry. Inhibition of S1PR2 with JTE-013 significantly ameliorated BLM-induced pathological changes and inflammatory cytokine levels. JTE-013 also significantly reduced the expression of RHOA/YAP pathway proteins and mitochondrial fission protein Drp1, apoptosis, and the colocalization of α-SMA with YAP, Drp1, and Tom20, as detected by immunohistochemistry, immunofluorescence staining, TUNEL, and Western blot. In vitro, S1PR2 and YAP knockdown downregulated RHOA/YAP pathway protein expression, Drp1 phosphorylation, and Drp1 translocation, promoted YAP phosphorylation and phenotypic transformation of MFN2, and inhibited the up-regulation of mitochondrial membrane potential, reactive oxygen species production, and cell apoptosis (7.13% vs. 18.14%), protecting the integrity of the mitochondrial dynamics. JTE-013 also inhibited the expression of fibrosis markers α-SMA, MMP-9, and COL1A1, and alleviated the symptoms of pulmonary fibrosis. Conclusively, JTE-013 has great anti-pulmonary fibrosis potential by regulating RHOA/YAP and mitochondrial fusion/fission.

Estrogen alleviates acute and chronic itch in mice.

Itching is associated with various skin diseases, including atopic dermatitis and allergic dermatitis, and leads to repeated scratching behavior and unpleasant sensation. Although clinical and laboratory research data have shown that estrogen is involved in regulating itch, the molecular and cellular basis of estrogen in itch sensation remains elusive. In the present study, it was found that estrogen-treated mice exhibited reduced scratching bouts when challenged with histamine, chloroquine, the proteinase-activated receptor-2 activating peptide SLIGRL-NH2 (SLIGRL), compound 48/80, and 5-hydroxytryptamine when compared with mice in the placebo group. Moreover, estrogen also suppressed scratching bouts in the mouse model of chronic itch induced by acetone-ether-water treatment. Notably, consistent with the behavioral tests, the present RNA-seq analysis showed that estrogen treatment caused significantly reduced expression levels of itch-related molecules such as Mas-related G-protein coupled receptor member A3, neuromedin B and natriuretic polypeptide b. In addition, estradiol attenuated histamine-induced and chloroquine-induced calcium influx in dorsal root ganglion neurons. Collectively, the data of the present study suggested that estrogen modulates the expression of itch-related molecules and suppresses both acute and chronic itch in mice.

Effect of FTY-720 on Pulmonary Fibrosis in Mice via the TGF-ß1 Signaling Pathway and Autophagy.

We investigated whether FTY-720 might have an effect on bleomycin-induced pulmonary fibrosis through inhibiting TGF-ß1 pathway, and up-regulating autophagy. The pulmonary fibrosis was induced by bleomycin. FTY-720 (1 mg/kg) drug was intraperitoneally injected into mice. Histological changes and inflammatory factors were observed, and EMT and autophagy protein markers were studied by immunohistochemistry and immunofluorescence. The effects of bleomycin on MLE-12 cells were detected by MTT assay and flow cytometry, and the related molecular mechanisms were studied by Western Blot. FTY-720 considerably attenuated bleomycin-induced disorganization of alveolar tissue, extracellular collagen deposition, and α-SMA and E-cadherin levels in mice. The levels of IL-1ß, TNF-α, and IL-6 cytokines were attenuated in bronchoalveolar lavage fluid, as well as protein content and leukocyte count. COL1A1 and MMP9 protein expressions in lung tissue were significantly reduced. Additionally, FTY-720 treatment effectively inhibited the expressions of key proteins in TGF-ß1/TAK1/P38MAPK pathway and regulated autophagy proteins. Similar results were additionally found in cellular assays with mouse alveolar epithelial cells. Our study provides proof for a new mechanism for FTY-720 to suppress pulmonary fibrosis. FTY-720 is also a target for treating pulmonary fibrosis.

Polydatin inhibits mitochondrial damage and mitochondrial ROS by promoting PINK1-Parkin-mediated mitophagy in allergic rhinitis.

Polydatin (PD), a natural product derived from Polygonum cuspidatum, has anti-inflammatory and antioxidant effects and has significant benefits in treating allergic diseases. However, its role and mechanism in allergic rhinitis (AR) have not been fully elucidated. Herein, we investigated the effect and mechanism of PD in AR. AR model was established in mice with OVA. Human nasal epithelial cells (HNEpCs) were stimulated with IL-13. HNEpCs were also treated with an inhibitor of mitochondrial division or transfected with siRNA. The levels of IgE and cellular inflammatory factors were examined by enzyme linked immunosorbent assay and flow cytometry. The expressions of PINK1, Parkin, P62, LC3B, NLRP3 inflammasome proteins, and apoptosis proteins in nasal tissues and HNEpCs were measured by Western blot. We found that PD suppressed OVA-induced epithelial thickening and eosinophil accumulation in the nasal mucosa, reduced IL-4 production in NALF, and regulated Th1/Th2 balance. In addition, mitophagy was induced in AR mice after OVA challenge and in HNEpCs after IL-13 stimulation. Meanwhile, PD enhanced PINK1-Parkin-mediated mitophagy but decreased mitochondrial reactive oxygen species (mtROS) production, NLRP3 inflammasome activation, and apoptosis. However, PD-induced mitophagy was abrogated after PINK1 knockdown or Mdivi-1 treatment, indicating a key role of the PINK1-Parkin in PD-induced mitophagy. Moreover, mitochondrial damage, mtROS production, NLRP3 inflammasome activation, and HNEpCs apoptosis under IL-13 exposure were more severe after PINK1 knockdown or Mdivi-1 treatment. Conclusively, PD may exert protective effects on AR by promoting PINK1-Parkin-mediated mitophagy, which further suppresses apoptosis and tissue damage in AR through decreasing mtROS production and NLRP3 inflammasome activation.

Gene expression profiles and bioinformatics analysis in lung samples from ovalbumin-induced asthmatic mice.

BACKGROUND: Asthma is characterized by chronic inflammation and airway remodeling. However, limited study is conducted on the gene expression profiles of ovalbumin (OVA) induced asthma in mice. Here, we explored the gene expression profiles in lung tissues from mice with OVA-induced asthma using microarray and bioinformatics analysis. METHODS: For establishment of OVA-induced asthma model, mice first received intraperitoneal sensitization with OVA on day 0, 7 and 14, followed by atomizing inhalation of OVA 3 times a week for 8 weeks. The lung tissues were collected and subjected to microarray analysis, bioinformatics analysis and expression validation. RESULTS: Microarray data of lung tissues suggested that 3754 lncRNAs and 2976 mRNAs were differentially expressed in lung tissues between control and asthmatic mice, including 1647 up-regulated and 2106 down-regulated lncRNAs, and 1201 up-regulated and 1766 down-regulated mRNAs. GO analysis displayed that the up-regulated genes were enriched in inflammatory response, leukocyte migration involved in inflammatory response, and Notch signaling pathway. KEGG pathway analysis indicated that the enriched pathway terms of the up-regulated gene included Toll-like receptor signaling pathway and Th17 cell differentiation signaling pathway. Additionally, based on the previously published literatures on asthma and inflammation, we screened out down-regulated genes, such as Smg7, Sumo2, and Stat5a, and up-regulated genes, such as Myl9, Fos and Tlr4. According to the mRNA-lncRNA co-expression network, we selected lncRNAs associated with above genes, including the down-regulated lncRNAs of NONMMUT032848, NONMMUT008873, NONMMUT009478, and NONMMUT006807, and the up-regulated lncRNAs of NONMMUT052633, NONMMUT05340 and NONMMUT042325. The expression changes of the above genes were validated in lung tissues by real-time quantitaive PCR and Western blot. CONCLUSIONS: Overall, we performed gene microarray on lung samples from OVA-induced asthmatic mice and summarized core mRNAs and their related lncRNAs. This study may provide evidence for further research on the therapeutic targets of asthma.

DEK deficiency suppresses mitophagy to protect against house dust mite-induced asthma.

DEK protein is highly expressed in asthma. However, the mechanism of DEK on mitophagy in asthma has not been fully understood. This study aims to investigate the role and mechanism of DEK in asthmatic airway inflammation and in regulating PINK1-Parkin-mediated mitophagy, NLRP3 inflammasome activation, and apoptosis. PINK1-Parkin mitophagy, NLRP3 inflammasome, and apoptosis were examined after gene silencing or treatment with specific inhibitors (MitoTEMPO, MCC950, and Ac-DEVD-CHO) in house dust mite (HDM) or recombinant DEK (rmDEK)-induced WT and DEK-/- asthmatic mice and BEAS-2B cells. The regulatory role of DEK on ATAD3A was detected using ChIP-sequence and co-immunoprecipitation. rmDEK promoted eosinophil recruitment, and co-localization of TOM20 and LC3B, MFN1 and mitochondria, LC3B and VDAC, and ROS generation, reduced protein level of MnSOD in HDM induced-asthmatic mice. Moreover, rmDEK also increased DRP1 expression, PINK1-Parkin-mediated mitophagy, NLRP3 inflammasome activation, and apoptosis. These effects were partially reversed in DEK-/- mice. In BEAS-2B cells, siDEK diminished the Parkin, LC3B, and DRP1 translocation to mitochondria, mtROS, TOM20, and mtDNA. ChIP-sequence analysis showed that DEK was enriched on the ATAD3A promoter and could positively regulate ATAD3A expression. Additionally, ATAD3A was highly expressed in HDM-induced asthma models and interacted with DRP1, and siATAD3A could down-regulate DRP1 and mtDNA-mediated mitochondrial oxidative damage. Conclusively, DEK deficiency alleviates airway inflammation in asthma by down-regulating PINK1-Parkin mitophagy, NLRP3 inflammasome activation, and apoptosis. The mechanism may be through the DEK/ATAD3A/DRP1 signaling axis. Our findings may provide new potential therapeutic targets for asthma treatment.

RUNX3 mediates keloid fibroblast proliferation through deacetylation of EZH2 by SIRT1.

BACKGROUND: Keloid is a benign proliferative fibrous disease featured by excessive fibroblast proliferation after skin injury. However, the mechanism of abnormal cell proliferation is still unclear. Herein, we investigated the mechanism of abnormal proliferation in keloids involving Sirtuin 1(SIRT1)/ Zeste Homolog 2 (EZH2)/ Runt-related transcription factor 3 (RUNX3).  METHODS: HE staining was used to observe the histopathological changes. Western blot was performed to detect SIRT1/EZH2/RUNX3 and cell cycle related proteins. RT-PCR detected EZH2 mRNA. After knockdown of EZH2 or overexpression of RUNX3, cell proliferation and cell cycle was analyzed. Immunoprecipitation was used to detect acetylated EZH2. RESULTS: The results showed that overexpression of RUNX3 inhibited cell proliferation and arrested cell cycle at G1/S phase, whereas inhibition of SIRT1 promoted cell proliferation and G1/S phase of the cell cycle. Knockdown of EZH2 promoted the expression of RUNX3, inhibited cell proliferation and shortened the progression of G1 to S phase. Simultaneous knockdown of EZH2 and inhibition of SIRT1 reversed these effects. Inhibition of SIRT1 increased its protein stability by increasing EZH2 acetylation, thereby reducing the expression of RUNX3 and promoting cell proliferation. CONCLUSIONS: Conclusively, the SIRT1/EZH2/RUNX3 axis may be an important pathway in the regulation of abnormal proliferation in keloids.

Analysis of Differentially Expressed MicroRNAs in OVA-induced Airway Remodeling Model Mice.

MicroRNAs (miRNAs) can participate in airway remodeling by regulating immune molecule expression. Here, we aimed to identify the differential miRNAs involved in airway remodeling. Airway remodeling was induced by ovalbumin in female BALB/C mice. The differentially expressed miRNAs were screened with microarray. GO (Gene Ontology) and KEGG enrichment analysis was performed. The miRNA target gene network and miRNA target pathway network were constructed. Verification with real-time PCR and Western blot was performed. We identified 63 differentially expressed miRNAs (50 up-regulated and 13 down-regulated) in the lungs of ovalbumin-induced airway remodeling mice. Real-time PCR confirmed that 3 miRNAs (mmu-miR-1931, mmu-miR-712-5p, and mmu-miR-770-5p) were significantly up-regulated, and 4 miRNAs (mmu-miR-128-3p, mmu-miR-182-5p, mmu-miR-130b-3p, and mmu-miR-20b-5p) were significantly down-regulated. The miRNA target gene network analysis identified key mRNAs in the airway remodeling, such as Tnrc6b (trinucleotide repeat containing adaptor 6B), Sesn3 (sestrin 3), Baz2a (bromodomain adjacent to zinc finger domain 2a), and Cux1 (cut like homeobox 1). The miRNA target pathway network showed that the signal pathways such as MAPK (mitogen-activated protein kinase), PI3K/Akt (phosphoinositide 3-Kinase/protein kinase B), p53 (protein 53), and mTOR (mammalian target of rapamycin) were closely related to airway remodeling in asthma. Collectively, differential miRNAs involved in airway remodeling (such as mmu-miR-1931, mmu-miR-712-5p, mmu-miR-770-5p, mmu-miR-128-3p mmu-miR-182-5p, and mmu-miR-130b-3p) as well as their target genes (such as Tnrc6b, Sesn3, Baz2a, and Cux1) and pathways (such as MAPK, PI3K/Akt, p53, mTOR pathways) have been identified. Our findings may help to further understand the pathogenesis of airway remodeling.

Comprehensive characterization of the chemical composition of Lurong dabu decoction and its absorbed prototypes and metabolites in rat plasma using UHPLC-Q Exactive Orbitrap-HRMS.

Lurong Dabu decoction (LRDBD) is an effective traditional Chinese Korean ethnic medicine prescription composed of eight herbs, which is used for treating asthma. However, its material basis has not been studied yet. Herein, the use of a new and highly sensitive UHPLC-Q Exactive Orbitrap-HRMS technique is proposed for the high-resolution and accurate identification of the material basis of LRDBD. We identified 122 compounds belonging to different groups in LRDBD. Among these, 23 ingredients produced by decoction were identified and compared with 8 single herb compounds. Moreover, 39 other significantly different compounds were identified. Additionally, 29 absorbed prototype components and 35 metabolites were identified in rat plasma. Half of the prototype components were originated from antler velvet, it has corroborated the compatibility theory of Sasang medicine. To the best of our knowledge, the material basis of LRDBD was characterized for the first time. Our findings provide basic data and a method for further discovering potential drug targets and revealing the action mechanism of LRDBD in asthma treatment.

Preparation and evaluation of LA-PEG-SPION, a targeted MRI contrast agent for liver cancer.

This study aims to synthesize a magnetic resonance imaging (MRI) contrast agent that can specifically target the asialoglycoprotein receptor of liver cancer cells and evaluate its ability as a targeted MRI contrast agent. Lactobionic acid (LA) and polyethylene glycol (PEG) were used to modify superparamagnetic iron oxide nanoparticles (SPION) to obtain LA-PEG-SPION. LA-PEG-SPION was uniformly spherical under the electron microscope, with regular morphology and good dispersion. The particle size of LA-PEG-SPION was about 30 ± 4.5 nm, and its surface potential was about 31 ± 1.5 mV. LA-PEG-SPION had no toxicity or low toxicity to HepG2 cells and HeLa cells, even at 400 µg/mL. The uptake of LA-PEG-SPION by HepG2 cells was higher than that of SPION, with increased blue-stained particles. The fluorescent labeling rate of HepG2 cells reached 68.8%, which was higher than that of the control group. In vitro, MRI showed that the T2-weighted signal intensity of HepG2 cells was lower than that of the control group. Conclusively, LA-PEG-SPION nanoparticles are synthesized in a simple and efficient way. They are successfully applied to the T2-weighted contrast-enhanced MRI in liver cancer in vitro, and they have the potential to be used for in vivo research and clinical studies.

miR-181-5p attenuates neutrophilic inflammation in asthma by targeting DEK.

We investigated the regulatory role of miR-181b-5p in neutrophilic asthma and its mechanisms by targeting DEK. DEK, matrix metalloproteinase (MMP)-2, and MMP-9 were overexpressed and the miR-181b-5p was decreased in mice with neutrophilic asthma. DEK was a direct target of miR-181b-5p. In mouse model, miR-181b-5p agomir had an inhibitory effect on airway inflammation and remodeling. miR-181b-5p inhibited DEK/p-GSK-3ßSer9/ß-catenin/MMP-9 pathway activation by regulating Wnt ligands in BEAS-2B and 16HBE cells. The ability of supernatants from human bronchial epithelial cells (hBECs) co-stimulated with CXCL8 (IL-8) and miR-181b-5p to induce NETs was weaker than that of IL-8 alone. Moreover, DEK overexpression led to excessive mitochondrial dysfunction, including DRP1 up-regulation, p-DRP1ser637 and MFN2 down-regulation, mitochondrial membrane potential loss, excessive mtROS generation and mitochondrial incompleteness. Interestingly, all these phenotypes were rescued by Wnt inhibitor DKK-1 and miR-181b-5p agomir. Additionally, inhibition of DRP1 with Mdivi-1 decreased MMP-9 on BEAS-2B cells. Overall, miR-181b-5p could attenuate neutrophilic asthma through inhibition of NETs release, DEK/p-GSK-3ßSer9/ß-catenin/MMP-9 pathway, DEK/Wnt/DRP1/MMP-9 and mitochondria damage. It may become a new therapeutic target for neutrophilic asthma.

Effects of G-Rh2 on mast cell-mediated anaphylaxis via AKT-Nrf2/NF-κB and MAPK-Nrf2/NF-κB pathways.

Background: The effect of ginsenoside Rh2 (G-Rh2) on mast cell-mediated anaphylaxis remains unclear. Herein, we investigated the effects of G-Rh2 on OVA-induced asthmatic mice and on mast cell-mediated anaphylaxis. Methods: Asthma model was established for evaluating airway changes and ear allergy. RPMCs and RBL-2H3 were used for in vitro experiments. Calcium uptake, histamine release and degranulation were detected. ELISA and Western blot measured cytokine and protein levels, respectively. Results: G-Rh2 inhibited OVA-induced airway remodeling, the production of TNF-α, IL-4, IL-8, IL-1ß and the degranulation of mast cells of asthmatic mice. G-Rh2 inhibited the activation of Syk and Lyn in lung tissue of OVA-induced asthmatic mice. G-Rh2 inhibited serum IgE production in OVA induced asthmatic mice. Furthermore, G-Rh2 reduced the ear allergy in IgE-sensitized mice. G-Rh2 decreased the ear thickness. In vitro experiments G-Rh2 significantly reduced calcium uptake and inhibited histamine release and degranulation in RPMCs. In addition, G-Rh2 reduced the production of IL-1ß, TNF-α, IL-8, and IL-4 in IgE-sensitized RBL-2H3 cells. Interestingly, G-Rh2 was involved in the FcεRI pathway activation of mast cells and the transduction of the Lyn/Syk signaling pathway. G-Rh2 inhibited PI3K activity in a dose-dependent manner. By blocking the antigen-induced phosphorylation of Lyn, Syk, LAT, PLCγ2, PI3K ERK1/2 and Raf-1 expression, G-Rh2 inhibited the NF-κB, AKT-Nrf2, and p38MAPK-Nrf2 pathways. However, G-Rh2 up-regulated Keap-1 expression. Meanwhile, G-Rh2 reduced the levels of p-AKT, p38MAPK and Nrf2 in RBL-2H3 sensitized IgE cells and inhibited NF-κB signaling pathway activation by activating the AKT-Nrf2 and p38MAPK-Nrf2 pathways. Conclusion: G-Rh2 inhibits mast cell-induced allergic inflammation, which might be mediated by the AKT-Nrf2/NF-κB and p38MAPK-Nrf2/NF-κB signaling pathways.

Protective effects of glaucocalyxin A on the airway of asthmatic mice.

The aim of this study is to investigate the protective effects of glaucocalyxin A (GLA) on airways in mouse models of asthma, concerning the inflammatory mediators, Th1/Th2 subgroup imbalance, and Toll-like receptor 4 (TLR4)/NF-κB signaling pathway. Hematoxylin and eosin/periodic acid-Schiff staining was used to observe the pathological changes in lung tissues. Inflammatory cytokine contents in the bronchoalveolar lavage fluid were detected by enzyme-linked immunosorbent assay. Protein expression levels were detected with Western blot, immunohistochemistry, and immunofluorescence. In vivo studies showed that, in ovalbumin (OVA)-induced asthmatic mouse models, the GLA treatments reduced the airway hyperresponsiveness and the secretion of inflammatory cells, declined the proliferation of goblet cells, decreased the levels of IL-4, IL-5, and IL-13, and increased the contents of interferon-γ and IL-12. Moreover, GLA inhibited the protein expression levels of TLR4, MyD88, TRAF6, and NF-κB in OVA-induced asthmatic mouse models. Further in vitro studies showed that GLA inhibited the expression of NF-κB, p-IκBα, tumor necrosis factor-α, IL-6, and IL-1ß and blocked the nuclear transfer of NF-κB in lipopolysaccharide-stimulated RAW264.7 macrophages. Conclusively, GLA can inhibit the inflammatory responses in OVA-induced asthmatic mice and inhibit the release of inflammatory factors in LPS-induced RAW264.7 macrophages, which may be related to the inhibition of TLR4/NF-κB signaling pathway.

MicroRNA-182-5p Attenuates Asthmatic Airway Inflammation by Targeting NOX4.

Bronchial asthma is characterized by chronic airway inflammation, airway hyperresponsiveness, and airway remodeling. MicroRNA (miRNA) has recently been implicated in the pathogenesis of asthma. However, the mechanisms of different miRNAs in asthma are complicated, and the mechanism of miRNA-182-5p in asthma is still unclear. Here, we aim to explore the mechanism of miRNA182-5p in asthma-related airway inflammation. Ovalbumin (OVA)-induced asthma model was established. MiRNA Microarray Analysis was performed to analyze the differentially expressed miRNAs in the asthma model. We found that the expression of miRNA-182-5p was significantly decreased in OVA-induced asthma. In vitro, IL-13 stimulation of BEAS-2B cells resulted in a significant up-regulation of NOX4 (nicotinamide adenine dinucleotide phosphate oxidase 4), accompanied by mitochondrial damage-induced apoptosis, NLRP3 (NOD-like receptor family pyrin domain-containing 3)/IL-1ß activation, and reduced miRNA-182-5p. In contrast, overexpression of miRNA-182-5p significantly inhibited epithelial cell apoptosis and NLRP3/IL-1ß activation. In addition, we found that miRNA-182-5p could bind to the 3' untranscripted region of NOX4 mRNA and inhibit epithelial cell inflammation by reducing oxidative stress and mitochondrial damage. In vivo, miRNA-182-5p agomir treatment significantly reduced the percentage of eosinophils in bronchoalveolar lavage fluid, and down-regulated Th2 inflammatory factors, including IL-4, IL-5, and OVA induced IL-13. Meanwhile, miRNA-182-5p agomir reduced the peribronchial inflammatory cell infiltration, goblet cell proliferation and collagen deposition. In summary, targeting miRNA-182-5p may provide a new strategy for the treatment of asthma.

Panax notoginseng saponin R1 attenuates allergic rhinitis through AMPK/Drp1 mediated mitochondrial fission.

We investigated whether Panax notoginseng saponin (PNS-R1) attenuates allergic rhinitis (AR) through AMPK/Drp1-mediated mitochondrial fission. AR model was established in mice by Ovalbumin (OVA). In vitro, human nasal epithelial cells (HNEpCs) were stimulated using recombinant human interleukin 13 (IL-13). PNS-R1 was administrated in vivo and in vitro. Then, HE staining of nasal tissue, ELISA detection of immunoglobulin E (IgE) and proinflammatory cytokine levels in serum and nasal lavage fluid, flow cytometry analysis of Th1/Th2 ratio and apoptosis, TUNEL staining, Western blot, detection of reactive oxygen species (ROS) and mitochondrial ROS, immunofluorescence analysis of Tom20 and mitochondrial fission protein Drp1 co-localization, and mitochondrial membrane potential detection, were performed. PNS-R1 attenuated allergic symptoms in AR mice, decreased OVA-specific IgE, IL-4, IL-6, IL-8, IL-13, and TNF-α levels, and restored the Th1/Th2 imbalance. Meanwhile, we found that PNS-R1 treatment significantly reduced apoptosis, ROS production, and co-localization of Tom20 and Drp1 in the nasal epithelium of AR mice. In vitro, we found that PNS-R1 upregulated mitochondrial membrane potential and reduced ROS and mitochondrial ROS production as well as Cleaved-caspase-3/9, Bax, Cyt-c, Apaf-1 expression and mitochondrial fission. Mechanistically, we found that PNS-R1 downregulated Drp1 phosphorylation (Ser 616) and Drp1 translocation in an AMPK-dependent manner, promoted MFN2 expression, and reduced TXNIP, NLRP3, Caspase-1, and IL-1ß expression. PNS-R1 may protect mitochondrial integrity by inhibiting AMPK/Drp1 and TXNIP/NLRP3 signaling pathway, thereby alleviating AR symptoms in mice. PNS-R1 may have great potential as a therapeutic agent for AR.

Sesamin Alleviates Asthma Airway Inflammation by Regulating Mitophagy and Mitochondrial Apoptosis.

Bronchial asthma poses a considerable burden on both individual patients and public health. Sesamin is a natural lignan that relieves asthma. However, the potential regulatory mechanism has not been fully validated. In this study, we revealed the mechanism of sesamin in inhibiting airway inflammation of asthma. In cockroach extract (CRE)-induced asthmatic mice, sesamin efficiently inhibited inflammatory cell infiltration, expressions of total and CRE-specific IgE in serum, and inflammatory cytokines (including IL-4, 5, 13) in bronchoalveolar lavage fluid. Further study revealed that sesamin inhibited Th2 cells in the mediastinal lymph nodes and spleen, the expression of PTEN-induced putative kinase 1 (PINK1) and Parkin, and apoptosis of lung airway epithelial cells. In vitro, sesamin had no significant cytotoxicity to BEAS-2B cells. Sesamin significantly increased TNF-α/IL-4-induced superoxide dismutase (SOD), catalase (CAT), heme oxygenase 1 (HO-1), and nuclear factor erythroid 2 related factor 2 (Nrf2), and decreased malondialdehyde. Sesamin also inhibited TNF-α/IL-4-induced mitochondrial reactive oxygen species, increased mitochondrial membrane potential, and reduced cell apoptosis as well as PINK1/Parkin expression and translocation to mitochondria. Conclusively, sesamin may relieve asthma airway inflammation by inhibiting mitophagy and mitochondrial apoptosis. Thus, sesamin may become a potential therapeutic agent for asthma.