Inhibitory Effects of Resveratrol on Airway Remodeling by Transforming Growth Factor-β/Smad Signaling Pathway in Chronic Asthma Model

Fangxiao Formula alleviates airway inflammation and remodeling in rats with asthma via suppression of transforming growth factor-β/Smad3 signaling pathway

Asthma is a common obstructive airway disease characterized by inflammation and remodeling with a progressive decline in lung function. Fangxiao Formula (FXF) is an herbal medicine that has achieved significant clinical benefits toward asthma patients, but the relevant mechanism has not yet been clarified. The aim of this study was to determine the inhibitory effects of FXF on airway inflammation and remodeling, and investigate the activities of TGF‑β/Smads signaling pathway in the rat asthma model. Rats were sensitized by ovalbumin (OVA) for six weeks to establish the asthma experimental model. OVA-challenged animals were randomly divided into 5 groups and received different concentrations of FXF or dexamethasone. The animals in blank control group received saline only. Lung tissues were collected and analyzed for determining the inflammatory cells infiltration, HE and PAS staining, airway wall thickness and collagen deposition. The productions of inflammatory cytokine productions were analyzed by ELISA in the bronchoalveolar lavage (BAL) fluid. Immunohistochemical analysis was performed to measure the expression of α-SMA and PCNA in lung tissue after the treatment of FXF. The levels of TGF-β were assessed by both immunohistology and western blotting, and the expression of p-Smad2/3 proteins were determined by western blotting analysis. Our results indicated that FXF attenuated the infiltration of inflammatory cells, decreased the production of Th2 cytokines and simultaneously increased the levels of Th1 cytokine in the asthma rat model. In addition, FXF reduced allergen-induced increased airway wall thickness, goblet cell hyperplasia and collagen deposition. Furthermore, the expression levels of TGF-β and p-Smad3 were obviously reduced after the treatment of FXF. These results indicate that FXF alleviates airway inflammation and remodeling by restoring the balance of Th1/Th2 cytokines and the TGF-β/Smad-3 pathway, therefor providing potential therapeutic approach for asthmatic patients.

Human pluripotent stem cell-derived mesenchymal stem cells prevent chronic allergic airway inflammation via TGF-β1-Smad2/Smad3 signaling pathway in mice

BACKGROUND

Asthma is a chronic disease involving inflamed airways, which were previously demonstrated, can be modulated by the mesenchymal stem cells derived from induced pluripotent stem cells (iPSC-MSCs). However, the long-term effects of iPSC-MSCs in inflamed airways are still unidentified. This study investigated the long-term effects and potential mechanisms involved in the immunomodulatory effects of iPSC-MSCs in the chronic mouse asthma model.

METHODS

Both human iPSC-MSCs and bone marrow (BM)-MSCs were transplanted into the long-term ovalbumin-induced mice before sensitization phase or during the challenge phase. Airway hyper-respnsiveness measurement, immunohistochemistry and ELISA were employed to assess the effects of MSCs. In addition, Smad2/3 levels were assessed by western blot analysis to investigate the possible mechanism involved.

RESULTS

The systemic administration of human iPSC-MSCs before the challenge protected the mice from the characters of the chronic allergic airway inflammation, in particular improving the airway remodeling and preventing fibrosis. In addition, the TGF-β1/Smad pathway was identified involved in the immunomodulatory effects of iPSC-MSCs on chronic allergic airway inflammation.

CONCLUSIONS

The study demonstrated that iPSC-MSCs are capable of preventing chronic allergic airway inflammation over a prolonged period, which further proved the iPSC-MSC therapeutic potential for allergic airway inflammation in a clinical scenario.

ITGB4 deficiency induces senescence of airway epithelial cells through p53 activation

Aging is characterized by a progressive loss of physiological integrity, leading to impaired organ function and, ultimately, increased vulnerability to death. Many complex diseases are related to aging, including asthma. In the lung, the airway epithelium serves as the first barrier to prevent the access of inspired external stimuli and dictates the initial stress responses. Notably, in the airway mucosa of asthma patients, an increase in senescent airway epithelial cells has been detected. Although it has been speculated that the senescence of airway epithelial cells could increase asthma susceptibility and aggravate asthma severity, the role of cell senescence in the development of asthma remains unclear. Integrin β4 (ITGB4) is a structural adhesion molecule with complex physiological functions that is downregulated in airway epithelial cells of asthma patients. This study demonstrates that the expression of ITGB4 in airway epithelial cells is downregulated significantly under oxidative stress or upon inflammatory stimulation. Moreover, we show that ITGB4 deficiency induces the senescence of airway epithelial cells through the activation of the p53 pathway both in vitro and in vivo. Together, our results demonstrate that airway epithelial senescence induced by ITGB4 deficiency after oxidative stress or inflammatory stimulation may be involved in the pathogenesis of asthma. Understanding the contribution of ITGB4 deficiency to the senescence of airway epithelial cells in asthma patients may provide new therapeutic approaches for the treatment of asthma.

Resveratrol Attenuates Allergic Asthma and Associated Inflammation in the Lungs Through Regulation of miRNA-34a That Targets FoxP3 in Mice

Asthma is a chronic inflammatory disease of airways mediated by T-helper 2 (Th2) cells involving complex signaling pathways. Although resveratrol has previously been shown to attenuate allergic asthma, the role of miRNA in this process has not been studied. We investigated the effect of resveratrol on ovalbumin-induced experimental allergic asthma in mice. To that end, BALB/c mice were immunized with ovalbumin (OVA) intraperitoneally followed by oral gavage of vehicle (OVA-veh) or resveratrol (100 mg/kg body) (OVA-res). On day 7, the experimental groups received intranasal challenge of OVA followed by 7 days of additional oral gavage of vehicle or resveratrol. At day 15, all mice were euthanized and bronchioalveolar fluid (BALF), serum and lung infiltrating cells were collected and analyzed. The data showed that resveratrol significantly reduced IL-5, IL-13, and TGF-β in the serum and BALF in mice with OVA-induced asthma. Also, we saw a decrease in CD3+CD4+, CD3+CD8+, and CD4+IL-4+ cells with increase in CD4+CD25+FOXP3+ cells in pulmonary inflammatory cell infiltrate in OVA-res group when compared to OVA-veh. miRNA expression arrays using lung infiltrating cells showed that resveratrol caused significant alterations in miRNA expression, specifically downregulating the expression of miR-34a. Additionally, miR-34a was found to target FOXP3, as evidenced by enhanced expression of FOXP3 in the lung tissue. Also, transfection studies showed that miR-34a inhibitor upregulated FOXP3 expression while miR-34a-mimic downregulated FOXP3 expression. The current study suggests that resveratrol attenuates allergic asthma by downregulating miR-34a that induces increased expression of FOXP3, a master regulator of Treg development and functions.

[Effects of montelukast sodium and bacterial lysates on airway remodeling and expression of transforming growth factor-β1 and Smad7 in guinea pigs with bronchial asthma]

OBJECTIVE

To study the effect of montelukast sodium (MK), a leukotriene receptor antagonist, and bacterial lysates (OM-85BV), used alone or in combination, on airway remodeling and the expression of transforming growth factor-β1 (TGF-β1) and Smad7 in guinea pigs with bronchial asthma and their correlation.

METHODS

A total of 40 male Hartley guinea pigs were randomly divided into normal control group, asthma group, MK group, OM-85BV group, and MK+OM-85BV group, with 8 guinea pigs in each group. Intraperitoneal injection of 10% ovalbumin (OVA) for sensitization and aerosol inhalation of 1% OVA for challenge were performed to establish a model of airway remodeling of asthma in all of the groups apart from the normal control group, which were treated with normal saline. In the stage of challenge by aerosol inhalation, the guinea pigs in the MK, OM-85BV, and MK+OM-85BV groups were given corresponding suspension by gavage, and those in the normal control and asthma groups were given an equal volume of normal saline by gavage. Bronchoalveolar lavage fluid (BALF) of the guinea pigs was collected within 24 hours after challenge, and ELISA was used to measure the levels of TGF-β1 and Smad7 in BALF. The guinea pigs were sacrificed and the pathological section of lung tissue was prepared to observe the degree of airway remodeling. An image analysis technique was used to measure perimeter of the basement membrane (Pbm), total bronchial wall area (Wat), and airway bronchial smooth muscle area (Wam). Pearson linear regression was used to investigate the correlation between two variables.

RESULTS

According to the lung pathological section, compared with the normal control group, the asthma, MK, OM-85BV, and MK+OM-85BV groups had significant thickening of bronchial smooth muscle and alveolar wall, significantly higher Wat/Pbm and Wam/Pbm, a significantly higher level of TGF-β1, and a significantly lower level of Smad7 (P<0.05). Compared with the asthma group, the MK, OM-85BV, and MK+OM-85BV groups had a significant improvement in pathological injury, significantly lower Wat/Pbm and Wam/Pbm, a significantly lower level of TGF-β1, and a significantly higher level of Smad7 (P<0.05). The MK+OM-85BV group had significantly greater improvements than the MK group and the OM-85BV group (P<0.05). The expression of TGF-β1 was negatively correlated with that of Smad7 and positively correlated with Wat/Pbm and Wam/Pbm, and the expression of Smad7 was negatively correlated with Wat/Pbm and Wam/Pbm (P<0.01).

CONCLUSIONS

MK and OM-85BV, used alone or in combination, can reduce airway remodeling in guinea pigs with asthma, and MK combined with OM-85BV has the best effect, possibly by reducing TGF-β1 expression, increasing Smad7 expression, and improving the TGF-β1/Smad7 imbalance.

[Effects of montelukast sodium and bacterial lysates on airway remodeling and expression of transforming growth factor-β1 and Smad7 in guinea pigs with bronchial asthma]

OBJECTIVE

To study the effect of montelukast sodium (MK), a leukotriene receptor antagonist, and bacterial lysates (OM-85BV), used alone or in combination, on airway remodeling and the expression of transforming growth factor-β1 (TGF-β1) and Smad7 in guinea pigs with bronchial asthma and their correlation.

METHODS

A total of 40 male Hartley guinea pigs were randomly divided into normal control group, asthma group, MK group, OM-85BV group, and MK+OM-85BV group, with 8 guinea pigs in each group. Intraperitoneal injection of 10% ovalbumin (OVA) for sensitization and aerosol inhalation of 1% OVA for challenge were performed to establish a model of airway remodeling of asthma in all of the groups apart from the normal control group, which were treated with normal saline. In the stage of challenge by aerosol inhalation, the guinea pigs in the MK, OM-85BV, and MK+OM-85BV groups were given corresponding suspension by gavage, and those in the normal control and asthma groups were given an equal volume of normal saline by gavage. Bronchoalveolar lavage fluid (BALF) of the guinea pigs was collected within 24 hours after challenge, and ELISA was used to measure the levels of TGF-β1 and Smad7 in BALF. The guinea pigs were sacrificed and the pathological section of lung tissue was prepared to observe the degree of airway remodeling. An image analysis technique was used to measure perimeter of the basement membrane (Pbm), total bronchial wall area (Wat), and airway bronchial smooth muscle area (Wam). Pearson linear regression was used to investigate the correlation between two variables.

RESULTS

According to the lung pathological section, compared with the normal control group, the asthma, MK, OM-85BV, and MK+OM-85BV groups had significant thickening of bronchial smooth muscle and alveolar wall, significantly higher Wat/Pbm and Wam/Pbm, a significantly higher level of TGF-β1, and a significantly lower level of Smad7 (P<0.05). Compared with the asthma group, the MK, OM-85BV, and MK+OM-85BV groups had a significant improvement in pathological injury, significantly lower Wat/Pbm and Wam/Pbm, a significantly lower level of TGF-β1, and a significantly higher level of Smad7 (P<0.05). The MK+OM-85BV group had significantly greater improvements than the MK group and the OM-85BV group (P<0.05). The expression of TGF-β1 was negatively correlated with that of Smad7 and positively correlated with Wat/Pbm and Wam/Pbm, and the expression of Smad7 was negatively correlated with Wat/Pbm and Wam/Pbm (P<0.01).

CONCLUSIONS

MK and OM-85BV, used alone or in combination, can reduce airway remodeling in guinea pigs with asthma, and MK combined with OM-85BV has the best effect, possibly by reducing TGF-β1 expression, increasing Smad7 expression, and improving the TGF-β1/Smad7 imbalance.

Epithelial folliculin enhances airway inflammation in aspirin-exacerbated respiratory disease

BACKGROUND

Clinical features of aspirin-exacerbated respiratory disease (AERD) are characterized by overproduction of cysteinyl leukotrienes (LT) and eosinophil activation, in which epithelial cells contribute to eosinophilic airway inflammation. Folliculin (FLCN) helps maintain the integrity of epithelial barrier, but little is known about FLCN in AERD.

OBJECTIVE

We investigated the role of FLCN in the pathogenic mechanisms of AERD.

METHODS

We recruited 178 subjects with AERD, 276 subjects with aspirin-tolerant asthma (ATA) and 71 normal healthy controls (NC) at Ajou Medical Center. Levels of FLCN and interleukin (IL)-8 in sera and supernatants were measured by ELISA. Peripheral blood eosinophils isolated from asthmatic patients were cocultured with human airway epithelial cells (HAECs) pretreated with LTE₄ , dexamethasone and montelukast. The intracellular expressions of FLCN, tight (TJ) (occludins, claudin-1) and adherens (AJ) junctions (E-cadherin) were analysed by Western blotting. shRNA was used to down-regulate FLCN (shFLCN) in HAECs.

RESULTS

Serum FLCN levels were significantly higher in AERD group than in ATA and NC groups (all P < 0.001). The cut-off value of 56.6 pg/mL was used to define the high FLCN phenotype (highFLCN). Asthmatic patients with highFLCN were associated with increased airway hyperresponsiveness to methacholine (P = 0.015). The serum FLCN level could discriminate AERD group from NC group with 82% sensitivity (AUC = 0.793, P < 0.001). When HAECs were exposed to LTE₄ , FLCN release was increased significantly (P < 0.05), which were amplified along with disruption of TJ and AJ expressions when HAECs were cocultured with eosinophils and LTE₄ (all P < 0.05); these effects were suppressed by dexamethasone and montelukast. FLCN knockdown reduced IL-8 release and occludin expression from shFLCN HAECs.

CONCLUSIONS

Our findings suggest that high LT and airway eosinophilia increased FLCN release from HAECs, which enhance epithelial activation and disruption. Modulation of FLCN may be a potential target for AERD.

Anti-Inflammatory Effects of Resveratrol: Mechanistic Insights

Inflammation is the principal response invoked by the body to address injuries. Despite inflammation constituting a crucial component of tissue repair, it is well known that unchecked or chronic inflammation becomes deleterious, leading to progressive tissue damage. Studies over the past years focused on foods rich in polyphenols with anti-inflammatory and immunomodulatory properties, since inflammation was recognized to play a central role in several diseases. In this review, we discuss the beneficial effects of resveratrol, the most widely investigated polyphenol, on cancer and neurodegenerative, respiratory, metabolic, and cardiovascular diseases. We highlight how resveratrol, despite its unfavorable pharmacokinetics, can modulate the inflammatory pathways underlying those diseases, and we identify future opportunities for the evaluation of its clinical feasibility.

A comprehensive review of the health perspectives of resveratrol

Many natural products present in our diet, including flavonoids, can prevent the progression of cancer and other diseases. Resveratrol, a natural polyphenol present in various fruits and vegetables, plays an important role as a therapeutic and chemopreventive agent used in the treatment of various illnesses. It exhibits effects against different types of cancer through different pathways. It additionally exerts antidiabetic, anti-inflammatory, and anti-oxidant effects in a variety of cell types. Furthermore, the cardiovascular protective capacities of resveratrol are associated with multiple molecular targets and may lead to the development of novel therapeutic strategies for atherosclerosis, ischemia/reperfusion, metabolic syndrome, and heart failure. Accordingly, this article presents an overview of recent developments in the use of resveratrol for the prevention and treatment of different diseases along with various mechanisms. In addition, the present review summarizes the most recent literature pertaining to resveratrol as a chemotherapeutic agent against multiple diseases and provides an assessment of the potential of this natural compound as a complementary or alternative medicine.

Resveratrol Ameliorates the Severity of Fibrogenesis in Mice with Experimental Chronic Pancreatitis

SCOPE

Resveratrol is generally considered beneficial to health-span and longevity since this dietary stilbenoid has been scrutinized for its activating property on the "rescue gene" sirtuin-1 that promotes cellular survival under stress. In addition to its antiaging property, our previous in vitro studies revealed that resveratrol notably inhibits the production of extracellular matrix (ECM) proteins in pancreatic stellate cells (PSCs), the classic effector cells against pancreatic injury.

OBJECTIVE

We aim to extrapolate resveratrol intervention to the management of fibrogenesis in mice with chronic pancreatitis.

METHODS AND RESULTS

C57/BL6 mice are given repetitive injections of cerulein (50 μg kg^-1  h^-1 ) for 6 weeks for the induction of chronic pancreatitis. We demonstrate that the oral administration of resveratrol (20 mg kg^-1  d^-1 ) effectively attenuated PSC activation, ECM deposition, fibrogenesis, and acinar atrophy in the pancreatitic parenchyma of cerulein-induced mice, as the damage index score was improved by 45.5%. The enhanced cell survival and preserved acinar integrity by resveratrol plausibly involves a perpetuated nuclear accumulation of Mist1 and a negative modulation of the Akt and p38 MAPK pathways.

CONCLUSION

We suggest that resveratrol is potentially a nutraceutical for the mitigations of pancreatic fibrosis in chronic pancreatitis for which no effective therapeutic measure is currently available.

TRPV1 Blocking Alleviates Airway Inflammation and Remodeling in a Chronic Asthma Murine Model

Purpose

Asthma is a chronic inflammatory airway disease characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. There is emerging interest in the involvement of the transient receptor potential vanilloid 1 (TRPV1) channel in the pathophysiology of asthma. This study examined whether TRPV1 antagonism alleviates asthma features in a murine model of chronic asthma.

Methods

BALB/c mice were sensitized to and challenged by ovalbumin to develop chronic asthma. Capsazepine (TRPV1 antagonist) or TRPV1 small interfering RNA (siRNA) was administered in the treatment group to evaluate the effect of TPV1 antagonism on AHR, airway inflammation, and remodeling.

Results

The mice displayed increased AHR, airway inflammation, and remodeling. Treatment with capsazepine or TRPV1 siRNA reduced AHR to methacholine and airway inflammation. Type 2 T helper (Th2) cytokines (interleukin [IL]-4, IL-5, and IL-13) were reduced and epithelial cell-derived cytokines (thymic stromal lymphopoietin [TSLP], IL-33, and IL-25), which regulate Th2 cytokine-associated inflammation, were also reduced. Airway remodeling characterized by goblet cell hyperplasia, increased α-smooth muscle action, and collagen deposition was also alleviated by both treatments.

Conclusions

Treatment directed at TRPV1 significantly alleviated AHR, airway inflammation, and remodeling in a chronic asthma murine model. The TRPV1 receptor can be a potential drug target for chronic bronchial asthma.

Resveratrol as a potential therapeutic drug for respiratory system diseases

Respiratory system diseases are common and major ailments that seriously endanger human health. Resveratrol, a polyphenolic phytoalexin, is considered an anti-inflammatory, antioxidant, and anticancer agent. Thanks to its wide range of biological activities, resveratrol has become a hotspot in many fields, including respiratory system diseases. Indeed, research has demonstrated that resveratrol is helpful to relieve pulmonary function in the general population. Meanwhile, growing evidence indicates that resveratrol plays a protective role in respiratory system diseases. This review aimed to summarize the main protective effects of resveratrol in respiratory system diseases, including its anti-inflammatory, antiapoptotic, antioxidant, antifibrotic, antihypertensive, and anticancer activities. We found that resveratrol plays a protective role in the respiratory system through a variety of mechanisms, and so it may become a new drug for the treatment of respiratory system diseases.

Influences of PON1 on airway inflammation and remodeling in bronchial asthma

This study aims to explore the influences of Paraoxonase-1 (PON1) involved in airway inflammation and remodeling in asthma. Mice were divided into control, asthma, asthma + PON1 and asthma + NC groups, and asthma models were established via aerosol inhalation of ovalbumin (OVA). HE, Masson, and PAS stains were used to observe airway inflammation and remodeling, Giemsa staining to assess inflammatory cells in bronchoalveolar lavage fluid (BALF), qRT-PCR and Western blot to detect PON1 expression, lipid peroxidation and glutathione assays to quantify malondialdehyde (MDA) activity and glutathione peroxidase (GSH) levels, ELISA to determine inflammatory cytokines and immunoglobulin, and colorimetry to detect PON1 activities. Additionally, mice lung macrophages and fibroblasts were transfected with PON1 plasmid in vitro; ELISA and qRT-PCR were performed to understand the effects of PON1 on inflammatory cytokines secreted by lung macrophages, MTT assay for lung fibroblasts proliferation and qRT-PCR and Western blot for the expressions of PON1, COL1A1, and fibronectin. After overexpression of PON1, the asthma mice had decreased inflammatory cell infiltration, fibrosis degree, and airway wall thickness; inflammatory cells and inflammatory cytokines in BALF were also reduced, expressions of OVA-IgE and IgG1, and MDA activity were decreased, but the expressions of OVA-IgG2a and INF-γ and GSH levels were increased. Besides, PON1 significantly inhibited microphage expression of LPS-induced inflammatory cytokines, lung fibroblast proliferation, and COL1A1 and fibronectin expression. Thus, PON1 could relieve airway inflammation and airway remodeling in asthmatic mice and inhibit the secretion of LPS-induced macrophage inflammatory cytokines and the proliferation of lung fibroblasts.

Regulation of airway inflammation and remodeling in asthmatic mice by TLR3/TRIF signal pathway

This paper aims to investigate the effect of Toll-like receptors 3 (TLR3)/TIR-domain-containing adapter-inducing interferon-β (TRIF) signal pathway on the airway inflammation and remodeling in asthmatic mice. C57BL/6 and TLR3^-/- mice were randomly divided into three groups (10 mice per group), including Control group (mice inhaled phosphate buffer saline (PBS)), Asthma group (mice inhaled ovalbumin (OVA)) and polyriboinosinic-ribocytidylic acid (poly (I: C)) group (asthmatic mice were injected intraperitoneally with TLR3 agonist poly (I: C)). Hematoxylin-eosin (HE) staining, Wright-Giemsa staining, Enzyme-linked immunosorbent assay (ELISA), Immunohistochemistry, Hydroxyproline assay, quantitative real time polymerase chain reaction (qRT-PCR) and Western blot were used to assess for the indices of airway inflammation and remodeling. In terms of WT mice, all asthma groups with or without the addition of poly (I: C) showed exaggerated inflammation and remodeling in the airways as compared to Control group, which were more seriously in poly (I: C) group than Asthma group. Furthermore, we observed the significant inhibition of airway inflammation and remodeling in the TLR3^-/- mice in both Asthma no matter with or without addition of poly (I: C) than the WT mice. TLR3 knockout could obviously relieve the airway inflammation and remodeling in asthma through inhibiting TLR3/TRIF signaling pathway.