Saxagliptin mitigates airway inflammation in a mouse model of acute asthma via modulation of NF-kB and TLR4

Anti-asthmatic and antioxidant activity of flavonoids isolated from Mentha longifolia subspecies typhoides (Briq.) Harley. and Mentha longifolia subspecies schimperi (Briq.) Briq. on ovalbumin-induced allergic asthma in mice: In-vivo and in-silico study

ETHNOPHARMACOLOGICAL RELEVANCE

Mentha longifolia L. has been employed to treat cough, lung inflammation, and bronchial asthma disorders.

AIM OF THE STUDY

Our study was carried out to investigate the medicinal effect of the flavonoids derived from M. longifolia, specifically didymin, linarin, rutin, and TMF, as well as the whole extracts of M. longifolia subsp. typhoides and M. longifolia subsp. schimperi, in comparison to dexa, in a mice model of ovalbumin-allergic asthma (OVA).

METHODS

After inhaling OVA, the mice developed acute asthma symptoms. Mice were subjected orally to Dexa and/or isolated flavonoids. The study assessed total and differential leukocyte counts, LDH concentration, and total protein concentration in BALF, reduced levels of GSH and total NOx products in lung tissues and analyzed the lung specimens by staining them with hematoxylin and eosin (H & E).

RESULTS

Histopathological analysis of the right lung lobes demonstrated that the isolated flavonoids exhibited a significant anti-inflammatory effect higher than Dexa as shown by decreasing the overall and distinct leukocyte counts, LDH levels, and total protein levels in BALF, as compared to the OVA group (p < 0.05). TMF was the most effective and the other tested flavonoids are more effective than Dexa but less than TMF. In addition, all tested flavonoids and Dexa significantly (p < 0.05) mitigated OVA-induced oxidative stress as evidenced by diminished lung NOx level and elevated GSH level. Computational docking studies proved recognition of didymin, linarin, rutin, and TMF to the human leukocyte elastase binding sites.

CONCLUSION

The tested flavonoids; didymin, linarin, rutin, and TMF successfully inhibit Ova-induced allergic asthma in mice through their anti-inflammatory and antioxidant activities and may represent promising candidate as a remedy for allergic asthma.

Gentisic acid attenuates ovalbumin-induced airway inflammation, oxidative stress, and ferroptosis through the modulation of Nrf2/HO-1 and NF-κB signaling pathways

Asthma, a lung disorder that causes impaired respiratory function, is characterized by an apparent infiltration of inflammatory cells. Gentisic acid (GA), a phenolic acid common in food ingredients, has antioxidant, antibacterial, and anti-inflammatory properties. Its potential application in mitigating asthma, however, remains unexplored. The current investigation studies GA's therapeutic potential for allergic asthma. BALB/c mice were challenged and sensitized to ovalbumin (OVA) to establish the animal model. We investigated how GA affected asthmatic behavior, leukocyte infiltration, histopathological alterations, oxidative stress, immunoglobulin E (IgE) production, and airway inflammation. ELISA and immunohistochemistry (IHC) techniques were employed to measure Nrf2, HO-1, and NF-κB's expression. To investigate the protein-ligand interaction between GA and Keap1, molecular docking analysis was utilized. The GA treatment significantly reduced nasal scratching, oxidative stress in the lungs, the infiltration of inflammatory cells, IgE content, iron accumulation, and NF-κB activation. It also upregulated Nrf2 and HO-1. Additionally, in silico studies revealed GA and Keap1 binding to activate Nrf2 by disrupting the Keap1-Nrf2 interaction. The study at hand is the first to investigate and report on the immunomodulatory impacts of GA on induced asthma in BALB/c mice. Our findings reveal that GA can be utilized as an anti-asthmatic agent via Nrf2/HO-1 and NF-κB pathway regulation.

Activation of AMPK/SIRT1/FOXO3a signaling by BMS-477118 (saxagliptin) mitigates chronic colitis in rats: uncovering new anti-inflammatory and antifibrotic roles

Ulcerative colitis (UC) is a debilitating chronic disease marked by persistent inflammation and intestinal fibrosis. Despite the availability of various treatments, many patients fail to achieve long-term remission, underscoring a significant unmet therapeutic need. BMS-477118, a reversible inhibitor of dipeptidyl peptidase 4 (DPP4), has demonstrated anti-inflammatory properties in preclinical and clinical studies with minimal adverse effects compared to other antidiabetic agents. However, the potential benefits of BMS-477118 in chronic UC have not yet been explored. In this study, we aimed to investigate the effects of BMS-477118 in rats subjected to chronic dextran sodium sulfate (DSS) administration. Our findings indicate that BMS-477118 activates the interconnected positive feedback loop involving AMPK, SIRT1, and FOXO3a, improving histological appearance in injured rat colons. BMS-477118 also reduced fibrotic changes associated with the chronic nature of the animal model, alleviated macroscopic damage and disease severity, and improved the colon weight-to-length ratio. Additionally, BMS-477118 prevented DSS-induced weight loss and enhanced tight junction proteins. These effects, in conjunction with reduced oxidative stress and its potential anti-inflammatory, antiapoptotic, and autophagy-inducing properties, fostered prolonged survival in rats with chronic UC. To conclude, BMS-477118 has the potential to activate the AMPK/SIRT1/FOXO3a signaling pathway in inflamed colons. These results suggest that the AMPK/SIRT1/FOXO3a pathway could be a new therapeutic target for UC. Further research is mandatory to explore the therapeutic possibilities of this pathway. Additionally, continued studies on the therapeutic potential of BMS-477118 and other DPP4 inhibitors are promising for creating new treatments for various conditions, including UC in diabetic patients.

4-Hydroxychalcone attenuates ovalbumin-induced allergic airway inflammation and oxidative stress by activating Nrf2/GPx4 pathway

Asthma is a lung condition characterized by impaired respiratory function and an apparent infiltration of inflammatory cells. Chalcones are substances that have attracted considerable interest in the disciplines of pharmaceutical chemistry and drug discovery due to their diverse biochemical processes, such as antioxidant, anti-inflammatory, anticancer, antibacterial, and others, but whether they can be used in asthma treatment has yet to be investigated. This study aimed to investigate the immunomodulatory effect of 4 hydroxychalcone (4-HC) against allergic asthma in mice. In this research, we investigated how 4-HC affected asthmatic behavior, leukocyte infiltration, histopathological alterations, oxidative stress, immunoglobulin E (IgE) production, and airway inflammation. Moreover, ELISA and immunohistochemistry (IHC) were used to measure the expression of Nrf2 and GPx4. 4-HC treatment significantly decreased lung oxidative stress, inflammatory cell infiltration, and IgE levels. According to our findings, we imply that 4-HC may be utilized as an anti-asthmatic agent through the upregulation of Nrf2/GPx4 signaling pathway.

The impact of diabetes mellitus on blood-tissue barrier regulation and vascular complications: Is the lung different from other organs?

Diabetes Mellitus presents a formidable challenge as one of the most prevalent and complex chronic diseases, exerting significant strain on both patients and the world economy. It is recognized as a common comorbidity among severely ill individuals, often leading to a myriad of micro- and macro-vascular complications. Despite extensive research dissecting the pathophysiology and molecular mechanisms underlying vascular complications of diabetes, relatively little attention has been paid to potential lung-related complications. This review aims to illuminate the impact of diabetes on prevalent respiratory diseases, including chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), idiopathic pulmonary fibrosis (IPF), tuberculosis (TB), pneumonia infections, and asthma, and compare the vascular complications with other vascular beds. Additionally, we explore the primary mechanistic pathways contributing to these complications, such as the expression modulation of blood-tissue-barrier proteins, resulting in increased paracellular and transcellular permeability, and compromised immune responses rendering diabetes patients more susceptible to infections. The activation of inflammatory pathways leading to cellular injury and hastening the onset of these respiratory complications is also discussed.

Linagliptin decreased the tumor progression on glioblastoma model

PURPOSE

Dipeptidyl peptidase-4 (DPP-4) inhibitors are oral hypoglycemic drugs and are used for type II diabetes. Previous studies showed that DPP-4 expression is observed in several tumor types and DPP-4 inhibitors suppress the tumor progression on murine tumor models. In this study, we evaluated the role of DPP-4 and the antitumor effect of a DPP-4 inhibitor, linagliptin, on glioblastoma (GBM).

METHODS

We analyzed DPP-4 expression in glioma patients by the public database. We also analyzed DPP-4 expression in GBM cells and the murine GBM model. Then, we evaluated the cell viability, cell proliferation, cell migration, and expression of some proteins on GBM cells with linagliptin. Furthermore, we evaluated the antitumor effect of linagliptin in the murine GBM model.

RESULTS

The upregulation of DPP-4 expression were observed in human GBM tissue and murine GBM model. In addition, DPP-4 expression levels were found to positively correlate with the grade of glioma patients. Linagliptin suppressed cell viability, cell proliferation, and cell migration in GBM cells. Linagliptin changed the expression of phosphorylated NF-kB, cell cycle, and cell adhesion-related proteins. Furthermore, oral administration of linagliptin decreases the tumor progression in the murine GBM model.

CONCLUSION

Inhibition of DPP-4 by linagliptin showed the antitumor effect on GBM cells and the murine GBM model. The antitumor effects of linagliptin is suggested to be based on the changes in the expression of several proteins related to cell cycle and cell adhesion via the regulation of phosphorylated NF-kB. This study suggested that DPP-4 inhibitors could be a new therapeutic strategy for GBM.

The mechanism of Sanzi Yangqin decoction for asthma treatment based on network pharmacology and experimental verification

BACKGROUND

Asthma is a chronic airway inflammatory disease characterized by airway inflammation, mucus hypersecretion, airway hyper-reactivity. Sanzi Yangqin Decoction (SZYQD) is widely prescribed for asthma treatment. Its anti-asthma activities have been reported in animal model, but the exact mechanism and targets of SZYQD in asthma treatment have not been fully elucidated.

METHODS

A network pharmacological approach was used to predict the active components, targets, and signalling pathways of SZYQD in asthma, including potential target prediction, protein‒protein interaction (PPI) network construction and analysis, and Gene Ont (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The active ingredients were identified from the SZYQD, and were molecular docked according to the results of network pharmacology. A mouse model of asthma induced by ovalbumin (OVA) and lipopolysaccharide (LPS) was constructed to evaluate the therapeutic effect of SZYQD. Furthermore, the effects of SZYQD and its active ingredients were tested in vitro for regulating inflammation and MUC5AC expression (two main pathophysiologic abnormalities of asthma) in macrophages and airway epithelial cells by using Real-time PCR and western blotting.

RESULTS

A total of 28 active ingredients and 111 HUB genes were screened in the relevant databases, including three key ingredients (luteolin, β-carotene, and Sinapine) and nine core target genes (JUN, CTNNB1, IL10, TP53, AKT1, STAT3, TNF, IL6 and EGFR). KEGG and GO analysis indicated that the potential anti-asthmatic mechanisms of SZYQD were related to PI3K-Akt signalling pathway and response to lipopolysaccharide, etc. In the in vivo asthmatic model, our findings demonstrated that SZYQD exerted a protective effect against asthmatic mice induced by OVA and LPS through the inhibition of inflammation and mucus overproduction. Consistently, cell experiments showed that the SZYQD extract or the key active ingredients luteolin significantly decreased lipopolysaccharide (LPS)-induced IL-6 expression and activation of the NF-κB pathway in macrophages. In addition, SZYQD extract or luteolin inhibited activation of the AKT pathway and expression of MUC5AC induced by EGF in airway epithelial cells.

CONCLUSION

The anti-asthmatic mechanism of SZYQD might be associated with inhibiting inflammation and airway mucus hypersecretion by regulating the NF-κB and AKT signalling pathways as predicted by network pharmacology, which provides more evidence for the application of SZYQD in asthma treatment.

Mechanism of action of certain medicinal plants for the treatment of asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Asthma is often treated and prevented using the pharmacological properties of traditional medicinal plants. These healthcare systems are among the most well-known, conveniently accessible, and economically priced in India and several other Asian countries. Traditional Indian Ayurvedic plants have the potential to be used as phyto-therapeutics, to create novel anti-asthmatic drugs, and as a cost-effective source of pharmaceuticals. Current conventional therapies have drawbacks, including serious side effects and expensive costs that interfere with treatment compliance and affect the patient's quality of life. The primary objective of the article is to comprehensively evaluate the advancement of research on the protective phytochemicals of traditional plants that target immune responses and signaling cascades in inflammatory experimental asthma models. The study would assist in paving the way for the creation of natural phytomedicines that are protective, anti-inflammatory, and immunomodulatory against asthma, which may then be used in individualized asthma therapy.

AIM OF THE STUDY

The study demonstrates the mechanisms of action of phytochemicals present in traditional medicinal plants, diminish pulmonary disorder in both in vivo and in vitro models of asthma.

MATERIALS AND METHODS

A comprehensive review of the literature on conventional plant-based asthma therapies was performed from 2006 to 2022. The study uses authoritative scientific sources such as PubMed, PubChem Compound, Wiley Online Library, Science Direct, Springer Link, and Google Scholar to collect information on potential phytochemicals and their mechanisms of action. World Flora Online (http://www.worldfloraonline.org) and Plants of the World Online (https://wcsp.science.kew.org) databases were used for the scientific names of medicinal plants.

RESULTS

The study outlines the phytochemical mechanisms of some traditional Ayurveda botanicals used to treat asthma. Active phytochemicals including curcumin, withaferin-A, piperine, glabridin, glycyrrhizin, 18β-glycyrrhetinic acid, trans-cinnamaldehyde, α-hederin, thymoquinone, eugenol, [6]-shogoal, and gingerol may treat asthma by controlling inflammation and airway remodeling. The study concluded that certain Ayurvedic plants' phytochemicals have the ability to reduce inflammation and modulate the immune system, that can effectively cure asthma.

CONCLUSION

Plants used in traditional Ayurvedic medicine have been utilized for millennia, advocating phyto-therapy as a treatment for a variety of illnesses. A theoretical foundation for the use of cutting-edge asthma treatments has been built with the growth of experimental research on traditional phytochemicals. In-depth phytochemical research for the treatment of asthma using Indian Traditional Ayurvedic herbs is compiled in the study. The approach for preventative therapeutics and cutting-edge alternatives to battle the molecular pathways in the pathophysiology of asthma are the key themes of the study. The phytochemical mechanism of action of traditional Ayurvedic herbs is explained to get the attention of the pharmaceutical industry so they can make future anti-asthma drugs for personalized asthma care in the community. The study develops strategies for customized phyto-therapeutics, concentrating on low-cost, side-effect-free approaches that employ bioactive phytochemicals from plants as the major source of effective anti-asthmatic therapy.

Exploring the molecular mechanism of linagliptin in osteosarcoma cell lines for anti-cancer activity

BACKGROUND

Finding new applications for widely used current drugs is a fast and effective technique for discovering new anticancer chemicals. Osteosarcoma (OS), the most prevalent form of bone cancer, has several side effects that significantly lower patients' quality of life. This study aims to systematically examine the anti-cancer activity of linagliptin (LG) in the osteosarcoma cell line Saos-2.

METHODS

MTT assays and flow cytometry were used to assess cell viability and apoptosis, respectively. qPCR array experiments were carried out to determine target gene expressions and explain the molecular mechanism of LG's action.

RESULTS

Linagliptin treatment significantly decreased the viability of Saos-2 cells and hFOB1.19 cells (p < 0.001). The treatment also induced increased apoptotic effects in both Saos-2 cells (p < 0.001) and hFOB1.19 cells (p < 0.05). qPCR assays were conducted to assess cancer pathway analysis after applying specific quantities of LG to Saos-2 and hFOB1.19 cells.

CONCLUSION

The findings of this study demonstrate that LG inhibits the proliferation of Saos-2 cells and induces cell death. LG supports cell death by suppressing the expression of specific genes involved in cancer pathways.

PM2.5 aggravates airway inflammation in asthmatic mice: activating NF-κB via MyD88 signaling pathway

The role of PM2.5 in the bronchial asthma remains unclear. In this study, the deficient mice of TLR4-/-, TLR2-/- and MyD88 -/- were used to establish asthma model. The effects of PM2.5 on the inflammatory response in lung tissue of these mice were observed. PM2.5 increased alveolar macrophages and neutrophils, up-regulated the IL-12 and KC expression in WT mice, but down-regulated their levels in TLR2 -/-, TLR4 -/- and MyD88 -/- mice. OVA+PM2.5 stimulated neutrophil count in WT mice, but it decreased in TLR2 -/- and TLR4 -/- mice. OVA+PM2.5 also increased the Eotaxin, IL-5, IL-13 and MCP-3 expression levels, and OVA specific IgE and IgG1 in serum also increased in WT group. PM2.5 may activate NF-κB through the TLR2/TLR4/MyD88 signaling pathway and aggravate allergic inflammation of lung in asthmatic mice. The microelements in PM2.5 granules, such as lipopolysaccharide, may be an important factor in the high incidence of asthma.

Saxagliptin promotes random skin flap survival

BACKGROUND

Flap necrosis is a common issue encountered in clinical flap transplantation surgery. Here, we assessed the effects of saxagliptin, a dipeptidyl peptidase-4 inhibitor, on flap survival and explored the underlying mechanisms.

METHODS

A dorsal McFarlane flap model was established in 36 rats, which were randomly divided into a high-dose saxagliptin (HS) group (saxagliptin, 30 mg/kg/day, n = 12), low-dose saxagliptin (LS) group (saxagliptin, 10 mg/kg/day, n = 12), and control group (n = 12). On day 7, flap survival was examined by eye in six rats from each group, along with determination of blood perfusion by laser Doppler flowmetry and angiogenesis by angiography. The remaining rats were sacrificed for harvesting of flap tissue. The status of the flap tissue was examined histopathologically by staining with hematoxylin and eosin (H&E). Oxidative stress was evaluated by determination of superoxide dismutase (SOD) activity and malonaldehyde (MDA) content. Gasdermin D (GSDMD), vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), NOD-like receptor pyrin domain containing 3 (NLRP3), interleukin (IL)-6, IL-18, Toll-like receptor 4 (TLR4), IL-1β, caspase-1, and nuclear factor-κB (NF-κB) expression were detected by immunohistochemical analysis.

RESULTS

The experimental group exhibited a larger area of flap survival, with more blood perfusion and neovascularization and better histopathological status than the control group. The degree of oxidative stress and the levels of NF-κB, TLR4, proinflammatory cytokines, and pyroptosis-associated protein were decreased in the experimental group, while the VEGF level was increased in a saxagliptin dose-dependent manner.

CONCLUSION

Saxagliptin promotes random skin flap survival.

The TLR4/NF-κB signaling pathway-mediated type 2 skewing of T helper cell in cough variant asthma was counteracted by ethanol extract of Anacyclus pyrethrum root

Type 2 T helper (Th2) cells-mediated immune response plays a pivotal role in the pathogenesis of cough variant asthma (CVA), and this study aims to determine the effect and mechanism of ethanol extract of Anacyclus pyrethrum root (EEAP) on regulating Th2 response in CVA. Peripheral blood mononuclear cells (PBMCs) collected from patients with CVA, and naive CD4⁺T cells induced by Th2-polarizing medium were administrated with EEAP. Interestingly, through conducting flow cytometry and enzyme linked immunosorbent assay method, we found that EEAP significantly alleviated Th2 skewing and increased Th1 response in these two kinds of cells. Results of western blot assay and quantitative reverse transcription PCR displayed that EEAP suppressed the expression of TLR4, total NF-κB p65, nuclear NF-κB p65 and the downstream genes. Subsequently, we proved that TLR4 antagonist E5564 played a similar improvement role to EEAP in Th1/Th2 imbalance, while combination of TLR4 agonist LPS and EEAP abolished the inhibitory effect of EEAP on Th2 polarization in Th2-induced CD4⁺T cells. Finally, CVA models induced by ovalbumin and capsaicin were established in cavies, and data showed that EEAP also improved Th1/Th2 imbalance in CVA in vivo, manifested in the increase of IL4⁺CD4⁺T cell ratio, Th2 cytokines (IL-4, IL-5, IL-6 and IL-13) and the decrease of Th1 cytokines (IL-2 and IFN-γ). Co-treatment of LPS and EEAP counteracted the inhibition of EEAP on Th2 response in CVA model cavies. Moreover, we found that EEAP mitigated airway inflammation and hyper-responsiveness in vivo, which was abolished by the combined application of LPS. In a word, EEAP restores Th1/Th2 balance in CVA through restraining the TLR4/NF-кB signaling pathway. This study may contribute to the clinical application of EEAP in CVA-related disease.

Toll-like receptor 4 is a key regulator of asthma exacerbation caused by aluminum oxide nanoparticles via regulation of NF-κB phosphorylation

Aluminum oxide nanoparticles (Al₂O₃ NPs) have recently been reported to cause an inflammatory response in the lungs, and studies are being conducted on their adverse effects, especially in patients with underlying lung diseases such as asthma. However, the underlying mechanism of asthma aggravation caused by Al₂O₃ NPs remains unclear. This study investigated whether Al₂O₃ NPs exacerbate ovalbumin (OVA)-induced asthma and focused on the correlation between toll-like receptor 4 (TLR4) signaling and Al₂O₃ NP-induced asthma exacerbation. Al₂O₃ NP exposure in asthmatic mice resulted in increased inflammatory cell counts in the lungs, airway hyperresponsiveness, and increased levels of inflammatory cytokines compared with only OVA-induced mice, and excessive secretion of mucus was observed in the airways. Moreover, Al₂O₃ NP exposure in OVA-induced mice increased the expression levels of TLR4, phospho-nuclear transcription factor-kappa B (p-NFκB), myeloid differentiation factor 88 (MyD88), and phospho-NF kappa B inhibitor alpha (p-IκBα). Furthermore, in the lungs of TLR4 knockout mice exposed to Al₂O₃ NPs and in a human airway epithelial cell line with down regulated TLR4, the expression levels of MyD88, p-NFκB, and p-IκBα were decreased, and asthma-related allergic responses were reduced. Therefore, we demonstrated that TLR4 is important for aggravation of asthma induced by Al₂O₃ NPs, and this study provides useful information regarding as yet undiscovered novel target signaling.

Ghrelin attenuates inflammation in diabetic lung disease by TLR4 pathway in vivo and in vitro

INTRODUCTION

Diabetic lung disease is already known as one of the diabetes complications, but report on its therapeutic strategy is rare. The present study aimed to add novel therapeutic strategy for diabetic lung disease, to reveal the protective effect of ghrelin on diabetic lung disease both in vivo and in vitro, and to discuss its probable molecular mechanism.

RESEARCH DESIGN AND METHODS

Diabetic mice and 16HBE cells were our research objects. We surveyed the effect of ghrelin on streptozotocin-induced lung tissue morphology changes by H&E staining. Furthermore, the changes of proinflammatory cytokines (interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)) were detected by ELISA. To expound the molecular mechanism, we detected critical proteins of TLR4 pathway and observed their changes by immunohistochemistry (IHC), real-time PCR and western blot analysis in vivo and in vitro, respectively.

RESULTS

The results of H&E staining showed that pathological alterations of the lung induced by hyperglycemia were ameliorated by ghrelin. The results of ELISA demonstrated that the elevated levels of IL-1β and TNF-α induced by hyperglycemia turned to decrease in the lung after ghrelin treatment. In the results of IHC, real-time PCR and western blot analysis, we found that the TLR4 pathway was elevated by hyperglycemia or high glucose and is remarkably inhibited by the treatment of ghrelin both in vivo and in vitro.

CONCLUSIONS

Ghrelin could inhibit inflammation of diabetic lung disease by regulating the TLR4 pathway. This study might affect research on diabetic lung disease, and the therapeutic potential of ghrelin for diabetic lung disease is worth considering.

ITGB4 deficiency in airway epithelia enhances HDM-induced airway inflammation through hyperactivation of TLR4 signaling pathway

Airway epithelial cells (AECs) are the first cell barrier of the respiratory system against external stimuli that play a critical role in the development of asthma. It is known that AECs play a key role in asthma susceptibility and severity. ITGB4 is a downregulated adhesion molecule in the airway epithelia of asthma patients, which was involved in the exaggerated lung inflammation after allergy stimulation. Toll-like receptor 4 (TLR4) in AECs has also been shown to play a crucial role in the development of lung inflammation in asthma patients. However, the specific intrinsic regulatory mechanism of TLR4 in AECs are still obscure. In this article, we demonstrated that ITGB4 deficiency in AECs enhances HDM-induced airway inflammation through hyperactivation of the TLR4 signaling pathway, which is mediated by inhibition of FYN phosphorylation. Moreover, TLR4-antagonist treatment or blockade of FYN can inhibit or exaggerate lung inflammation in HDM-stressed ITGB4-deficient mice, separately. Together, these results demonstrated that ITGB4 deficiency in AECs enhances HDM-induced lung inflammatory response through the ITGB4-FYN-TLR4 axis, which may provide new therapeutic approaches for the management of lung inflammation in asthma.

House dust mite-induced endoplasmic reticulum stress mediates MUC5AC hypersecretion via TBK1 in airway epithelium

Purpose: Endoplasmic reticulum (ER) stress regulates mucus hypersecretion, and may activate downstream factors via TBK1 signaling to induce gene expression. However, it remains unclear whether ER stress promotes airway mucus secretion through the TBK1 pathway. We aimed to investigate the role of the TBK1 pathway in the regulation of MUC5AC expression in a mouse model of house dust mite (HDM)-induced allergic asthma. Materials and Methods: Mice with HDM-induced asthma and human bronchial epithelial BEAS-2B cells were treated with amlexanox, an anti-allergy drug (25 μM), or 4-PBA (10 mM). Tissue and cell samples were collected. Tissue samples were stained with hematoxylin and eosin (H&E) or periodic acid Schiff (PAS) to evaluate pathology. Protein expression was analyzed by western blotting and immunofluorescence. Results: Mice exposed to HDM presented ER stress and hypersecretion of mucus Muc5ac from airway epithelial cells (p < 0.001). Similar results were observed in BEAS-2B cells following exposure to HDM. Both in vivo and in vitro studies revealed that HDM-induced ER stress induced MUC5AC overexpression via TBK1 signaling. Amlexanox and 4-PBA markedly reduced mucus production and weakened the TBK1 signal, which mediates MUC5AC hypersecretion. Conclusion: TBK1 plays a pivotal role in HDM-induced ER stress, leading to overproduction of MUC5AC in the asthmatic airway epithelium. The overproduction of MUC5AC can be significantly decreased by inhibiting TBK1 or ER stress using 4-PBA. These findings highlight potential target-specific therapies for patients with chronic allergic asthma.

Diabetic endothelial microangiopathy and pulmonary dysfunction

Type 2 diabetes mellitus (T2DM) is a widespread metabolic condition with a high global morbidity and mortality rate that affects the whole body. Their primary consequences are mostly caused by the macrovascular and microvascular bed degradation brought on by metabolic, hemodynamic, and inflammatory variables. However, research in recent years has expanded the target organ in T2DM to include the lung. Inflammatory lung diseases also impose a severe financial burden on global healthcare. T2DM has long been recognized as a significant comorbidity that influences the course of various respiratory disorders and their disease progress. The pathogenesis of the glycemic metabolic problem and endothelial microangiopathy of the respiratory disorders have garnered more attention lately, indicating that the two ailments have a shared history. This review aims to outline the connection between T2DM related endothelial cell dysfunction and concomitant respiratory diseases, including Coronavirus disease 2019 (COVID-19), asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).

Utility of Hypoglycemic Agents to Treat Asthma with Comorbid Obesity

Adults with obesity may develop asthma that is ineffectively controlled by inhaled corticosteroids and long-acting beta-adrenoceptor agonists. Mechanistic and translational studies suggest that metabolic dysregulation that occurs with obesity, particularly hyperglycemia and insulin resistance, contributes to altered immune cell function and low-grade systemic inflammation. Importantly, in these cases, the same proinflammatory cytokines believed to contribute to insulin resistance may also be responsible for airway remodeling and hyperresponsiveness. In the past decade, new research has emerged assessing whether hypoglycemic therapies impact comorbid asthma as reflected by the incidence of asthma, asthma-related emergency department visits, asthma-related hospitalizations, and asthma-related exacerbations. The purpose of this review article is to discuss the mechanism of action, preclinical data, and existing clinical studies regarding the efficacy and safety of hypoglycemic therapies for adults with obesity and comorbid asthma.

HPLC-DAD analysis of Quercus leucotrichophora extract and appraisal of its antiasthmatic potential via modulation of aquaporins, inflammatory, and oxidative stress biomarkers in Albino mice

Herbal drugs offer an alternative approach for the treatment of diseases like asthma due to low cost and comparatively less adverse effects in contrast to synthetic drugs. Leaves of Quercus leucotrichophora are traditionally used for the treatment of asthma. The study was aimed to assess the anti-asthmatic activity of Quercus leucotrichophora (QL) methanolic (QLME) and aqueous extracts (QLAE) in ovalbumin-(OVA) induced asthma and chemical characterization of QL extract by High Performance Liquid Chromatography-Diode array detector (HPLC-DAD). Animals were inoculated with OVA (i.p) on day 1 and 14 followed by intranasal challenge on 27th and 29th day. Both extracts of QL at 600, 300 and 150 mg/kg and dexamethasone (2 mg/kg) l were administered consecutively from days 15-26 via oral gavage. The QL extracts notably reduced (p < 0.0001-p < 0.05) total and differential leukocyte counts in blood and BALF and serum IgE levels in contrast to disease control. Both extracts and Dex substantially improved activities of superoxide dismutase, catalase, and GSH, while reduced malondialdehyde level in treated mice. Treatment with extracts and Dex caused significant (p < 0.0001-p < 0.05) downregulation of tumor necrosis factor-α, interleukin-4, - 5, - 13, - 6, - 1β, and NF-κB whereas, increased expression of Aquaporin (AQP) 1 and AQP5 in contrast to disease control. It was inferenced from findings that both extract of QL exhibited notable antiasthmatic potential might be due to presence of Daidzein-glucuronic acid, 3-Hydroxyphloretin 6'-hexoside, Catechin, Quercetin, and Kaemferol.

Sword Bean (Canavalia gladiata) Pod Exerts Anti-Allergic and Anti-Inflammatory Effects through Modulation of Th1/Th2 Cell Differentiation

Allergy is an immunoglobulin E (IgE)-mediated process, and its incidence and prevalence have increased worldwide in recent years. Therapeutic agents for allergic diseases are continuously being developed, but side effects follow when used for a long-term use. Therefore, treatments based on natural products that are safe for the body are urgently required. Sword bean (Canavalia gladiata) pod (SBP) has been traditionally used to treat inflammatory diseases, but there is still no scientific basis for its anti-allergic effect. Accordingly, this study investigates the anti-allergic effect and its mechanism of SBP in vitro and in vivo. SBP reduced the nitric oxide production and decreased mRNA and protein expression of inflammatory mediates (inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2)), and inhibited the phosphorylation of nuclear factor kappa B (NF-κB), a major signaling molecule in the inflammatory response. Additionally, SBP extract treatment inhibited phosphatidylinositol-3-kinase/mammalian target of rapamycin (PI3K/mTOR) signaling activity to further inhibit degranulation and allergy mediator generation and control the balance of Th1/Th2 cells, which can induce an allergic reaction when disrupted. Furthermore, the SBP extract exhibited anti-allergic effects in anti-dinitrophenyl IgE-induced RBL-2H3 cells and ovalbumin-treated mice. These findings have potential clinical implications for the treatment as well as prevention of allergic diseases.

Cytokine-Induced JAK2-STAT3 Activates Tissue Regeneration under Systemic or Local Inflammation

We investigated the immune response mechanisms under systemic and local inflammation using mouse models whereby lipopolysaccharide (LPS) was administered intraperitoneally to induce systemic inflammation, and epicutaneous sensitization with ovalbumin was used to induce local inflammation. LPS increased the immune cell infiltration in the cardiac muscle near the aorta, alveoli, hepatic sinusoid, renal interstitium, and the submucosal layer of the duodenum. Similarly, ovalbumin increased the abundance of macrophages in the skin. Both LPS and ovalbumin induced NF-κB p65 and IκBα phosphorylation, as well as the expression of NF-κB target genes (TLR4, IL6, and TNFα). Additionally, both LPS and ovalbumin led to an increase in the absolute IL-1β, IL-6, and TNFα serum levels and cytokine-related janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) phosphorylation. Moreover, the activated JAK2/STAT3 signaling increased the number of Ki67-positive cells (proliferating cells) and development pathway target gene expression (regeneration) in the inflammation models. In conclusion, LPS and ovalbumin increase immune cell infiltration in tissues, NF-κB activation, cytokine levels in serum, cytokine-stimulated JAK2/STAT3 signaling, and tissue regeneration.

Linagliptin ameliorates acetic acid-induced colitis via modulating AMPK/SIRT1/PGC-1α and JAK2/STAT3 signaling pathway in rats

Ulcerative colitis is a chronic inflammatory disease, profoundly affecting the patient's quality of life and is associated with various complications. Linagliptin, a potent DPP- IV inhibitor, shows favorable anti-inflammatory effects in several animal model pathologies. To this end, the present study aimed to investigate the anti-inflammatory effect of linagliptin in a rat model of acetic acid-induced colitis. Moreover, the molecular mechanisms behind this effect were addressed. Accordingly, colitis was established by the administration of a 2 ml 6% acetic acid intrarectally and treatment with linagliptin (5 mg/kg) started 24 h after colitis induction and continued for 7 days. On one hand, the DPP-IV inhibitor alleviated the severity of colitis as evidenced by a decrease of disease activity index (DAI) scores, colon weight/length ratio, macroscopic damage, and histopathological deteriorations. Additionally, linagliptin diminished colon inflammation via attenuation of TNF-α, IL-6, and NF-κB p65 besides restoration of anti-inflammatory cytokine IL-10. On the other hand, linagliptin increased levels of p-AMPK, SIRT1, and PGC-1α while abolishing the increment in p-JAK2 and p-STAT3. In parallel linagliptin reduced mTOR levels and upregulated expression levels of SHP and MKP-1 which is postulated to mediate AMPK-driven JAK2/STAT3 inhibition. Based on these findings, linagliptin showed promising anti-inflammatory activity against acetic acid-induced colitis that is mainly attributed to the activation of the AMPK-SIRT1-PGC-1α pathway as well as suppression of the JAK2/STAT3 signaling pathway that might be partly mediated through AMPK activation.

Dexmedetomidine alleviates airway hyperresponsiveness and allergic airway inflammation through the TLR4/NF‑κB signaling pathway in mice

Dexmedetomidine (DEX) suppresses inflammatory responses and protects against organ injury. The aim of the present study was to investigate the effect of DEX on airway hyperresponsiveness (AHR) and allergic airway inflammation, as well as its underlying mechanism of action in a murine model of ovalbumin (OVA)-induced asthma. A total of 30 female BALB/c mice were divided into 6 groups (n=5 mice/group): Control, OVA, OVA + DEX (20, 30 or 50 µg/kg) and OVA + TAK-242 [a toll-like receptor 4 (TLR4) inhibitor]. The mice were intraperitoneally injected with 20, 30 or 50 µg/kg DEX 1 h before OVA challenge. AHR to inhaled methacholine (Mch) was measured, and the mice were sacrificed 24 h after the last challenge. AHR following Mch inhalation was measured using the FlexiVent apparatus. Hematoxylin and eosin, periodic acid-Schiff and Wright-Giemsa staining was performed to evaluate inflammatory cell infiltration in the lung tissue. The levels of IL-4, IL-5 and IL-13 in the bronchoalveolar lavage fluid were analyzed using ELISA, and their mRNA expression levels in the lung tissue were examined using reverse transcription-quantitative PCR. The protein expression of TLR4, NF-κB and phosphorylated (p)NF-κB in the lung tissue was also detected using immunohistochemistry. In the murine OVA-induced asthma model, DEX decreased AHR following Mch inhalation and reduced the infiltration of inflammatory cells. IL-4, IL-5 and IL-13 levels in the bronchoalveolar lavage fluid were significantly lower following DEX treatment. Furthermore, DEX treatment inhibited the expression of TLR4, NF-κB and p-NF-κB in the lung tissue and exhibited a similar effect to TAK-242 treatment. In conclusion, DEX may attenuate AHR and allergic airway inflammation by inhibiting the TLR4/NF-κB pathway. These results suggested that DEX may represent a potential anti-inflammatory agent for the treatment and management of patients with asthma.

Association of dipeptidyl peptidase-4 inhibitor use and the risk of asthma development among type 2 diabetes patients

Background:

Numerous studies have shown that dipeptidyl peptidase-4 inhibitors (DPP-4i) may regulate immunological pathways implicated in asthma. The association between DPP-4i use and risk of asthma development is limited, however.

Aim:

We aimed to evaluate if DPP-4i treatment in individuals with type 2 diabetes mellitus (T2DM) is associated with a lower risk and severity of asthma.

Methods:

We performed a population-based retrospective cohort study using the Longitudinal National Health Insurance Research database between 2008 and 2015. After one-to-four propensity score matching from 1,914,201 patients with defined criteria, we enrolled 3001 patients who were on DPP-4i (DPP-4i group) for a diagnosis of T2DM but without a diagnosis of asthma for further analysis. Cox proportional hazards regression analysis was performed to estimate and compare the risk of developing and severity of asthma, including no acute exacerbations event (No-AE), acute exacerbations (AEs), status asthmaticus (Status), and required endotracheal intubation (ET-tube intubated), between the two groups.

Results:

The participants had a mean age of 66.05 ± 17.23 years and the mean follow-up time was 4.96 ± 4.39 years. The risk of asthma development was significantly lower in the DPP-4i group than in the non-DPP-4i group [adjusted hazard ratio (HR) = 0.65; 95% confidence interval (CI) = 0.29–0.83; p < 0.001], with a class effect. This trend was observed for severity of asthma as No-AE (HR = 0.55; 95% CI = 0.24–0.70; p < 0.001), AE (HR = 0.57; 95% CI = 0.26–0.73; p < 0.001), and Status (HR = 0.78; 95% CI = 0.35–0.99; p = 0.047), but not in ET-tube intubated cases (HR = 0.96; 95% CI = 0.43–1.22; p = 0.258).

Conclusion:

The use of DPP-4i decreased the risk and severity of asthma with a class effect among No-AE, AE, status of asthma events, but not in ET-tube intubated events. Our report suggests that DPP-4i may play a role in attenuating the impact of asthma on incidence in the future and on more severe forms of disease exacerbation in T2DM patients.

The Roles of Dipeptidyl Peptidase 4 (DPP4) and DPP4 Inhibitors in Different Lung Diseases: New Evidence

CD26/Dipeptidyl peptidase 4 (DPP4) is a type II transmembrane glycoprotein that is widely expressed in various organs and cells. It can also exist in body fluids in a soluble form. DPP4 participates in various physiological and pathological processes by regulating energy metabolism, inflammation, and immune function. DPP4 inhibitors have been approved by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes mellitus. More evidence has shown the role of DPP4 in the pathogenesis of lung diseases, since it is highly expressed in the lung parenchyma and the surface of the epithelium, vascular endothelium, and fibroblasts of human bronchi. It is a potential biomarker and therapeutic target for various lung diseases. During the coronavirus disease-19 (COVID-19) global pandemic, DPP4 was found to be an important marker that may play a significant role in disease progression. Some clinical trials on DPP4 inhibitors in COVID-19 are ongoing. DPP4 also affects other infectious respiratory diseases such as Middle East respiratory syndrome and non-infectious lung diseases such as pulmonary fibrosis, lung cancer, chronic obstructive pulmonary disease (COPD), and asthma. This review aims to summarize the roles of DPP4 and its inhibitors in infectious lung diseases and non-infectious diseases to provide new insights for clinical physicians.

Anti-Diabetic Drugs GLP-1 Agonists and DPP-4 Inhibitors may Represent Potential Therapeutic Approaches for COVID-19

The fast spread of coronavirus 2019 (COVID-19) calls for immediate action to counter the associated significant loss of human life and deep economic impact. Certain patient populations like those with obesity and diabetes are at higher risk for acquiring severe COVID-19 disease and have a higher risk of COVID-19 associated mortality. In the absence of an effective and safe vaccine, the only immediate promising approach is to repurpose an existing approved drug. Several drugs have been proposed and tested as adjunctive therapy for COVID-19. Among these drugs are the glucagon-like peptide-1 (GLP-1) 2 agonists and the dipeptidylpeptidase-4 (DPP-4) inhibitors. Beyond their glucose-lowering effects, these drugs have several pleiotropic protective properties, which include cardioprotective effects, anti-inflammatory and immunomodulatory activities, antifibrotic effects, antithrombotic effects, and vascular endothelial protective properties. This narrative review discusses these protective properties and addresses their scientific plausibility for their potential use as adjunctive therapy for COVID-19 disease.

Saxagliptin defers thioacetamide-induced hepatocarcinogenesis in rats: A novel suppressive impact on Wnt/Hedgehog/Notch1 signaling

AIM

Hepatocellular carcinoma (HCC) is a highly invasive form of hepatic cancer. It is a highly intricate disease with multiple pathophysiological mechanisms underlying its pathogenesis.

MATERIALS AND METHODS

The results of the current investigation shed light on the ability of saxagliptin (SAXA) (12.5 mg/kg) to defer HCC progression in an experimental model of thioacetamide (TAA)-induced hepatocarcinogenesis.

RESULTS

SAXA administration improved liver function biomarkers, with a concomitant histopathological recovery. Mechanistically, the observed hepatoprotective impact was associated with significant suppression of the hepatic content of Wnt3a, β-catenin, Notch1, Smo, and Gli2 and enhanced expression of GSK 3β. Nevertheless, the hepatic expression of PCNA, P53, and cyclin D1 was significantly enhanced, with a parallel increase in the tumor expression of caspase-3. Thus, it appears that SAXA significantly enhanced tumor apoptosis, with concomitant suppression of HCC proliferation.

CONCLUSION

SAXA deferred experimentally-induced HCC via suppressing Wnt/Hedgehog/Notch1 Signaling, with enhanced tumor apoptosis and suppressed proliferation.

The role of incretins and incretin-based drugs in autoimmune diseases

Incretin hormones, including glucagon-like peptide (GLP)-1, GLP-2 and glucose-dependent insulinotropic polypeptide (GIP), are gastrointestinal peptides secreted from enteroendocrine cells. These hormones play significant roles in many physiological processes via binding to G-protein coupled receptors (GPCRs) on different organs and tissues; one of them is the immunomodulatory effect on the immune system and its molecular components such as cytokines and chemokines. Anti-inflammatory effects of incretins and dependent molecules involving long-acting analogs and DPP4 inhibitors through regulation of T and B cell activation may attenuate autoimmune diseases caused by immune system disorders in mistakenly recognizing self as the foreign agent. In this review, we investigate incretin effects on the immune system response and the potential benefits of incretin-based therapy for treating autoimmune diseases.

Graviola mitigates acetic acid-induced ulcerative colitis in rats: insight on apoptosis and Wnt/Hh signaling crosstalk

In this study, we elucidated the potential protective effects of graviola leaves, compared with sulfasalazine, against acetic acid (AA)-induced ulcerative colitis (UC) in rats. Twenty-eight mature male rats were divided into four groups, Sham, Colitis, Colitis/Sulfa, and Colitis/Graviola, and were treated orally with either saline, saline, sulfasalazine (100 mg/kg/day), or graviola (100 mg/kg/day), respectively, for 7 days. On the 4th day, UC was induced by transrectal administration of 4% AA. Colon tissues were excised for macroscopic and histopathological evaluation and immunohistochemical analysis of caspase-3, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax). Also, levels of oxidative mediators, Wnt family member1 (Wnt1), smoothened (Smo), and glioblastoma-1 (Gli1) were evaluated. Macroscopic and histopathological examination revealed that both graviola and sulfasalazine significantly mitigated colonic damage. Besides, both treatments significantly alleviated AA-induced oxidative stress, as evidenced by reduced nitric oxide (No) and malondialdehyde (MDA) levels and myeloperoxidase (MPO) activity and raised reduced glutathione (GSH) content. Both treatments significantly attenuated AA-induced apoptosis via downregulating the expression of Bax and caspase-3 and upregulating the expression of the anti-apoptotic protein, Bcl-2. Furthermore, downregulation of mRNA expression of Wnt1 with concomitant upregulation of Smo and Gli1 was observed in rats treated with either sulfasalazine or graviola. Based on these observations, graviola may attenuate AA-induced UC, at least partially, by modulating apoptosis and Wingless/Int1 (Wnt) and hedgehog (Hh) signaling crosstalk.

Profibrotic mechanisms of DPP8 and DPP9 highly expressed in the proximal renal tubule epithelial cells

BACKGROUND

DPP8 and DPP9 have been demonstrated to play important roles in multiple diseases. Evidence for increased gene expression of DPP8 and DPP9 in tubulointerstitium was found to be associated with the decline of kidney function in chronic kidney disease (CKD) patients, which was observed in the Nephroseq human database. To examine the role of DPP8 and DPP9 in the tubulointerstitial injury, we determined the efficacy of DPP8 and DPP9 on epithelial-to-mesenchymal transition (EMT) and tubulointerstitial fibrosis (TIF) as well as the underlying mechanisms.

METHODS

We conducted the immunofluorescence of DPP8 and DPP9 in kidney biopsy specimens of CKD patients, established unilateral ureteral obstruction (UUO) animal model, treated with TC-E5007 (a specific inhibitor of both DPP8 and DPP9) or Saxagliptin (positive control) or saline, and HK-2 cells model.

RESULTS

We observed the significantly increased expression of DPP8 and DPP9 in the renal proximal tubule epithelial cells of CKD patients compared to the healthy control subjects. DPP8/DPP9 inhibitor TC-E5007 could significantly attenuate the EMT and extracellular matrix (ECM) synthesis in UUO mice, all these effects were mediated via interfering with the TGF-β1/Smad signaling. TC-E5007 treatment also presented reduced renal inflammation and improved renal function in the UUO mice compared to the placebo-treated UUO group. Furthermore, the siRNA for DPP8 and DPP9, and TC-E5007 treatment decreased EMT- and ECM-related proteins in TGF-β1-treated HK-2 cells respectively, which could be reversed significantly by transduction with lentivirus-DPP8 and lentivirus-DPP9.

CONCLUSION

These data obtained provide evidence that the DPP8 and DPP9 could be potential therapeutic targets against TIF.

PI3K/AKT/mTOR and TLR4/MyD88/NF-κB Signaling Inhibitors Attenuate Pathological Mechanisms of Allergic Asthma

Asthma is an inflammatory airway disease wherein bronchoconstriction, airway inflammation, and airway obstruction during asthma attacks are the main problems. It is recognized that imbalance of Th1/Th2 and Th17/Treg is a critical factor in asthma pathogenesis. Manipulation of these with signaling molecules such as mTOR, PI3K, Akt, and MyD88 can control asthma. Mouse model of allergic asthma was produced and treated with ketamine, metformin, metformin and ketamine, triciribine, LY294002, and torin2. MCh challenge test, BALf's Eos Count, the IL-4, 5, INF-γ, eicosanoid, total IgE levels were determined. The MUC5a, Foxp3, RORγt, PI3K, mTOR, Akt, PU.1, and MyD88 gene expressions and histopathology study were done. Asthma groups that were treated with all six components had reduced Penh value, total IgE, IL-4 and IL-5 levels, MUC5a, RORγt, MyD88 and mTOR expression, goblet cell hyperplasia, and mucus hyper-secretion. The eosinophil percentage and Cys-LT level were decreased by metformin and ketamine, triciribine, LY294002, and torin2. The level of IFN-γ was increased in triciribine, LY294002, and torin2. Metformin, metformin and ketamine, triciribine, LY294002, and torin2 reduced Akt and PI3K expression, peribronchial and perivascular inflammation, and increased expression of Foxp3. Torin2 had an effect on PU.1 expression. Inhibition of PI3K/AKT/mTOR and TLR4/MyD88/NF-κB signaling with targeted molecules can attenuate asthma pathology and play an important role in airways protection.

Therapeutic effects and mechanisms study of Hanchuan Zupa Granule in a Guinea pig model of cough variant asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Hanchuan Zupa Granule (HCZP), a traditional Chinese ethnodrug, has the functions of supressing a cough, resolving phlegm, warming the lungs, and relieving asthma. In clinical practice employing traditional Chinese medicine (TCM), HCZP is commonly used to treat acute colds, cough and abnormal mucous asthma caused by a cold, or "Nai-Zi-Lai" in the Uygur language. Studies have confirmed the use of HCZP to treat cough variant asthma (CVA) and other respiratory diseases. However, the pharmacological mechanisms of HCZP remain unrevealed.

AIM OF THE STUDY

To investigate the anti-tussive and anti-asthmatic effects and the possible pharmacological mechanisms of HCZP in the treatment of CVA.

MATERIALS AND METHODS

A guinea pig CVA animal model was established by intraperitoneal injection of ovalbumin (OVA) combined with intraperitoneal injection of aluminium hydroxide adjuvant and atomized OVA. Meanwhile, guinea pigs with CVA received oral HCZP (at dosages of 0.571, 0.285 and 0.143 g/kg bodyweight). The number of coughs induced by aerosol capsaicin was recorded, and the airway hyperresponsiveness (AHR) of CVA guinea pigs was detected with the FinePointe series RC system. H&E staining of lung tissues was performed to observe pathological changes. ELISA was used to detect inflammatory cytokines. qRT-PCR and western blotting analyses were used to detect the expression of Th1-specific transcription factor (T-bet), Th2-specific transcription factor (GATA3), and Toll-like receptor 4 (TLR4) signal transduction elements. These methods were performed to assess the protective effects and the potential mechanisms of HCZP on CVA.

RESULTS

Great changes were found in the CVA guinea pig model after HCZP treatment. The number of coughs induced by capsaicin in guinea pigs decreased, the body weights of guinea pigs increased, and inflammation of the eosinophilic airway and AHR were reduced simultaneously. These results indicate that HCZP has a significant protective effect on CVA. A pharmacological study of HCZP showed that the levels of interleukin-4 (IL-4) and IL-5 and tumour necrosis factor-α (TNF-α) in serum decreased. The amount of interferon-γ (IFN-γ) increased, mRNA and protein expression of TLR4 and GATA3 weakened, and mRNA and protein expression of T-bet increased.

CONCLUSIONS

HCZP ameliorated the symptoms of guinea pigs with CVA induced by OVA by regulating the Th1/Th2 imbalance and TLR4 receptors.

Krill oil and low-dose aspirin combination mitigates experimentally induced silicosis in rats: role of NF-κB/TGF-β1/MMP-9 pathway

This study is an attempt to assess pulmonary protective and antifibrotic potentials of a combination of aspirin, a widely used anti-inflammatory and cardioprotective agent, and krill oil, a naturally occurring omega-3 fatty acid source, against silica-induced pulmonary injury. For silicosis induction, silica particles (50 mg/rat, 0.1 mL 0.9% NaCl) were instilled intranasally into rats. Aspirin (10 mg/kg/day), krill oil (40 mg/kg/day), or their combination was administered orally for 56 days following silica exposure. Results showed that oral aspirin and krill oil combination significantly mitigated silica-induced pulmonary injury. Bronchoalveolar lavage fluid examination showed a decreased lactate dehydrogenase activity, total protein content, and accumulation of total and differential inflammatory cells. Oral aspirin and krill oil combination significantly attenuated silica-induced oxidative stress through the restoration of reduced glutathione concentration and catalase activity in addition to alleviation of elevated malondialdehyde and total nitric oxide contents. Moreover, aspirin and krill oil combination revealed considerable mitigation of silica-induced upregulated expression of the inflammatory and fibrotic mediators: nuclear factor kappa-B, transforming growth factor-β1, and matrix metalloproteinase-9. The antifibrotic effect was also evidenced through the decreased hydroxyproline content and the obvious restoration of lung architecture, as demonstrated upon histopathological examination. In conclusion, oral aspirin and krill oil combination can confer pulmonary protective, anti-inflammatory, and antifibrotic potentials against silica-induced pulmonary injury. This impact could be credited to the ability of this combination to activate resolution mechanisms, which, in turn, suppress the expression of inflammatory and fibrotic biomarkers and replenish antioxidant stores.

Baicalin regulates the development of pediatric asthma via upregulating microRNA-103 and mediating the TLR4/NF-κB pathway

Pediatric asthma seriously endangers the well-being and health of children worldwide. Baicalin (BA) protects against diverse disorders, including asthma. Therefore, this study explored the mechanism of BA in pediatric asthma. The ovalbumin (OVA)-induced asthmatic mouse model was established to evaluate BA efficacy from aspects of oxidative stress, inflammation, blood cells in bronchoalveolar lavage fluid (BALF) and collagen deposition. Differentially expressed microRNAs (miRs) in BA-treated mice were analyzed. Effects of BA on PDGF-BB-induced smooth muscle cells (SMCs) were assessed. miR downstream mRNA and the related pathway were predicted and verified, and their effects on asthmatic mice were evaluated. BA effectively reversed OVA-induced oxidative stress and inflammation, as well as decreased the number of total cells, eosinophils and neutrophils in BALF, and collagen deposition. miR-103 was significantly upregulated after BA treatment. BA inhibited the abnormal proliferation of PDGF-BB-induced SMCs, which was prevented by miR-103 knockdown. miR-103 targeted TLR4 and regulated the extent of NF-κB phosphorylation. In vivo, miR-103 inhibition weakened the alleviating effects of BA on asthma, which was then reversed after silencing of TLR4. We highlighted that BA has the potency to halt the pediatric asthma progression via miR-103 upregulation and the TLR4/NF-κB axis inhibition.

Renoprotective Effects of DPP-4 Inhibitors

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD) worldwide. Dipeptidyl peptidase (DPP)-4 inhibitors are widely used in the treatment of patients with type 2 diabetes (T2D). DPP-4 inhibitors reduce glucose levels by inhibiting degradation of incretins. DPP-4 is a ubiquitous protein with exopeptidase activity that exists in cell membrane-bound and soluble forms. It has been shown that an increased renal DPP-4 activity is associated with the development of DKD. A series of clinical and experimental studies showed that DPP-4 inhibitors have beneficial effects on DKD, independent of their glucose-lowering abilities, which are mediated by anti-fibrotic, anti-inflammatory, and anti-oxidative stress properties. In this review article, we highlight the current understanding of the clinical efficacy and the mechanisms underlying renoprotection by DPP-4 inhibitors under diabetic conditions.

Qingfei oral liquid alleviates airway hyperresponsiveness and mucus hypersecretion via TRPV1 signaling in RSV-infected asthmatic mice

Pediatric asthma is exacerbated by Respiratory Syncytial Virus (RSV) infection, and Transient Receptor Potential Vanilloid 1 (TRPV1) promotes production of inflammatory cytokines and mucus hypersecretion in the pathology of this disease. Our previous research revealed that Qingfei oral liquid (QF) inhibited airway inflammation and mucus hypersecretion in RSV-infected asthmatic mice models and that this may be associated with the TRPV1-regulation of NF-κB and Mucin 5AC (MUC5AC) expression, but the exact mechanism is unknown. In the present study, LC-MS was used for analyzing the chemicals in QF, ovalbumin (OVA)-induced asthmatic mice inhaled RSV three consecutive times to create an RSV-infected asthmatic model. We found treatment from QF alleviated airway hyperresponsiveness (AHR) and reduced congestion, edema, and infiltration of inflammatory cells into pulmonary tissues. Additionally, QF was found to decrease expression of NF-κB and its downstream inflammatory cytokines IL-1β, IL-4, IL-5, and IL-13, as well as a decrease in MUC5AC and pro-inflammatory cytokines in PKC via a reduction in Protein Kinase C-dependent signaling. These findings suggest that QF can alleviate AHR and mucus hypersecretion caused by RSV infection in asthmatic mice, and its mechanism may be associated with the regulation of the TRPV1 signaling pathway.

ER Stress Amelioration by Saxagliptin Protects the Liver Against Fructose-induced Insulin Resistance

BACKGROUND/AIM

The study is aimed to demonstrate whether saxagliptin treatment may reduce endoplasmic reticulum (ER) stress, oxidative damage, and inflammation in the liver of fructose-induced insulin resistance (IR) rats.

MATERIAL AND METHODS

Twenty-eight rats were divided as control, IR, saxagliptin treatment (ST) and IR+ST groups. IR caused by fructose (10%) administration for 10 weeks and, ST was administered for 15 d. The liver tissues were obtained from rats. ER stress markers were analyzed using Real-Time PCR. Oxidative stress was measured. The inflammation in the liver was detected by the streptavidin-biotin immunostaining method.

RESULTS

The values of total oxidant/antioxidant status were the same between control and IR rats. The numbers of IL-6, NF-κB and PPARγ immune⁺ cells showed significant changes in the liver among four groups. The increased mRNA expression levels of ER stress and apoptosis markers as GRP78, PERK, IRE1α, ATF-4 and -6, CHOP, Caspase-3, -8, -9 and -12 in IR reduced with ST.

CONCLUSION

These findings indicate that saxagliptin treatment may ameliorate IR by reducing ER stress rather than inflammation and oxidative stress in the liver.