Gprc5a-deficiency confers susceptibility to endotoxin-induced acute lung injury via NF-κB pathway

Susceptibility to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) varies greatly among patients in sepsis/septic shock. The genetic and biochemical reasons for the difference are not fully understood. G protein coupled receptor family C group 5 member A (GPRC5A), a retinoic acid target gene, is predominately expressed in the bronchioalveolar epithelium of lung. We hypothesized that Gprc5a is important in controlling the susceptibility to ALI or ARDS. In this study, we examined the susceptibility of wild-type and Gprc5a-knockout (ko) mice to induced ALI. Administration of endotoxin LPS induced an increased pulmonary edema and injury in Gprc5a-ko mice, compared to wild-type counterparts. Consistently, LPS administration induced higher levels of inflammatory cytokines (IL-1β and TNFα) and chemokine (KC) in Gprc5a-ko mouse lungs than in wild-type. The enhanced pulmonary inflammatory responses were associated with dysregulated NF-κB signaling in the bronchioalveolar epithelium of Gprc5a-ko mouse lungs. Importantly, selective inhibition of NF-κB through expression of the super-repressor IκBα in the bronchioalveolar epithelium of Gprc5a-ko mouse lungs alleviated the LPS-induced pulmonary injury, and inflammatory response. Thus, Gprc5a is critical for lung homeostasis, and Gprc5a deficiency confers the susceptibility to endotoxin-induced pulmonary edema and injury, mainly through NF-κB signaling in bronchioalveolar epithelium of lung.     

Small interfering RNA targeting NF-κB attenuates lipopolysaccharide-induced acute lung injury in rats

Background

Veterinary cardiology, especially electrocardiography, has shown major advancements for all animal species. Consequently, the number of ovine species used as experimental animals has increased to date. Few studies have been published on ovine systematic electrocardiography, particularly with respect to lamb physiology and neonatology. This study aimed to standardize the values of normal waves, complexes, and intervals of the electrocardiogram (ECG) in clinically Bergamasca healthy neonatal lambs, used as experimental animals. Serial computerized electrocardiography was performed in 10 male and 12 female neonates on the 1st, 7th, 14th, 21st, 28th, and 35th days of age. The following parameters were analyzed: heart rate and rhythm, duration and amplitude of waves, duration of intervals, and heart electrical axis.

Results

During the first 35 days of life, (1) the sinusal heart rhythm was predominant, (2) there was a progressive decrease in the heart rate and R and T wave amplitude, and (3) a progressive increase in the PR, QT, and RR intervals. Finally, we confirmed that various components of neonatal evolution were more discernible in the augmented unipolar leads (aVF), which we recommend should be preferentially used in future studies. No significant statistical alterations were observed between males and females in relation to the analyzed parameters.

Conclusions

The information assimilated in this study is anticipated to enhance the diagnosis of multiple congenital heart defects in Bergamasca lambs and could be implemented in studies that use ovine species as experimental models.

     

Correlation between oxidative stress and NF-κB signaling pathway in the obesity-asthma mice

Molecular Biology Reports - In this study, a mice model of obesity-asthma was established. We investigated the correlation between oxidative stress and NF-κB signaling pathway in the lung...     

Dehydrozingerone ameliorates Lipopolysaccharide induced acute respiratory distress syndrome by inhibiting cytokine storm,oxidative stress via modulating the MAPK/NF-κB pathway

BackgroundInflammation-mediated lung injury is a major cause of health problems in many countries and has been the leading cause of morbidity/mortality in intensive care units. In the current COVID-19 pandemic, the majority of the patients experienced serious pneumonia resulting from inflammation (Acute respiratory distress syndrome/ARDS). Pathogenic infections cause cytokine release syndrome (CRS) by hyperactivation of immune cells, which in turn release excessive cytokines causing ARDS. Currently, there are no standard therapies for viral, bacterial or pathogen-mediated CRS.PurposeThis study aimed to investigate and validate the protective effects of Dehydrozingerone (DHZ) against LPS induced lung cell injury by in-vitro and in-vivo models and to gain insights into the molecular mechanisms that mediate these therapeutic effects.MethodsThe therapeutic activity of DHZ was determined in in-vitro models by pre-treating the cells with DHZ and exposed to LPS to stimulate the inflammatory cascade of events. We analysed the effect of DHZ on LPS induced inflammatory cytokines, chemokines and cell damage markers expression/levels using various cell lines. We performed gene expression, ELISA, and western blot analysis to elucidate the effect of DHZ on inflammation and its modulation of MAPK and NF-κB pathways. Further, the prophylactic and therapeutic effect of DHZ was evaluated against the LPS induced ARDS model in rats.ResultsDHZ significantly (p < 0.01) attenuated the LPS induced ROS, inflammatory cytokine, chemokine gene expression and protein release in macrophages. Similarly, DHZ treatment protected the lung epithelial and endothelial cells by mitigating the LPS induced inflammatory events in a dose-dependent manner. In vivo analysis showed that DHZ treatment significantly (p < 0.001) mitigated the LPS induced ARDS pathophysiology of increase in the inflammatory cells in BALF, inflammatory cytokine and chemokines in lung tissues. LPS stimulated neutrophil-mediated events, apoptosis, alveolar wall thickening and alveolar inflammation were profoundly reduced by DHZ treatment in a rat model.ConclusionThis study demonstrates for the first time that DHZ has the potential to ameliorate LPS induced ARDS by inhibiting cytokine storm and oxidative through modulating the MAPK and NF-κB pathways. This data provides pre-clinical support to develop DHZ as a potential therapeutic agent against ARDS.     

Downregulated microRNA-27b attenuates lipopolysaccharide-induced acute lung injury via activation of NF-E2-related factor 2 and inhibition of nuclear factor κB signaling pathway

Acute lung injury (ALI) is a life-threatening, diffuse heterogeneous lung injury characterized by acute onset, pulmonary edema, and respiratory failure. Lipopolysaccharide (LPS) is a leading cause for ALI and when administered to a mouse it induces a lung phenotype exhibiting some of the clinical characteristics of human ALI. This study focused on investigating whether microRNA-27b (miR-27b) affects ALI in a mouse model established by LPS-induction and to further explore the underlying mechanism. After model establishment, the mice were treated with miR-27b agomir, miR-27b antagomir, or D-ribofuranosylbenzimidazole (an inhibitor of nuclear factor-E2-related factor 2 [Nrf2]) to determine levels of miR-27b, Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells nuclear factor κB (NF-κB), p-NF-κB, and heme oxygenase-1 (HO-1). The levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF) were determined. The results of luciferase activity suggested that Nrf2 was a target gene of miR-27b. It was indicated that the Nrf2 level decreased in lung tissues from ALI mice. The downregulation of miR-27b decreased the levels of IL-1β, IL-6, and TNF-α in BALF of ALI mice. Downregulated miR-27b increased Nrf2 level, thus enhancing HO-1 level along with reduction of NF-κB level as well as the extent of NF-κB phosphorylation in the lung tissues of the transfected mice. Pathological changes were ameliorated in LPS-reduced mice elicited by miR-27b inhibition. The results of this study demonstrate that downregulated miR-27b couldenhance Nrf2 and HO-1 expressions, inhibit NF-κB signaling pathway, which exerts a protective effect on LPS-induced ALI in mice.     

Resolvin D1 attenuates inflammation in lipopolysaccharide-induced acute lung injury through a process involving the PPARγ/NF-κB pathway

Background

Docosahexaenoic acid (DHA) and DHA-derived lipid mediators have recently been shown to possess anti-inflammatory and pro-resolving properties. In fact, DHA can down-regulate lipolysaccharide (LPS)-induced activation of NF-κB via a PPARγ-dependent pathway. We sought to investigate the effects of the novel DHA-derived mediator resolvin D1 (RvD1) on LPS-induced acute lung injury and to determine whether these effects occur via a PPARγ-dependent pathway.

Methods

BALB/c mice aged 6–8 weeks were randomly divided into seven groups: two control groups receiving saline or RvD1 (600 ng) without LPS; a control group receiving LPS only; an experimental group receiving RvD1 (300 ng) or RvD1 (600 ng), followed by LPS; a group receiving the PPARγ antagonist GW9662; and a group receiving GW9662, then RvD1 (600 ng) and finally LPS. LPS (50 μM) and saline were administered intratracheally. RvD1 was injected intravenously 24 h and 30 min before LPS, while GW9662 was injected intravenously 30 min before RvD1. Mice were killed at 6, 12, and 24 h. Samples of bronchoalveolar lavage fluid (BALF) were analyzed for cell counts and cytokine analysis. Lung tissues were collected for histology, Western blotting and electrophoretic mobility shift assays (EMSAs).

Results

At all three time points, groups receiving either dose of RvD1 followed by LPS had significantly lower total leukocyte counts and levels of TNF-α and IL-6 levels in BALF than did the group given only LPS. RvD1 markedly attenuated LPS-induced lung inflammation at 24 h, based on hematoxylin-eosin staining of histology sections. RvD1 activated PPARγ and suppressed IκBα degradation and NF-κB p65 nuclear translocation, based on Western blots and EMSAs. The PPARγ inhibitor GW9662 partially reversed RvD1-induced suppression of IκBα degradation and p65 nuclear translocation.

Conclusions

These results suggest that RvD1 may attenuate lung inflammation of LPS-induced acute lung injury by suppressing NF-κB activation through a mechanism partly dependent on PPARγ activation.     

Rea regulates microglial polarization and attenuates neuronal apoptosis via inhibition of the NF-κB and MAPK signalings for spinal cord injury repair

Inflammation and neuronal apoptosis aggravate the secondary damage after spinal cord injury (SCI). Rehmannioside A (Rea) is a bioactive herbal extract isolated from Rehmanniae radix with low toxicity and neuroprotection effects. Rea treatment inhibited the release of pro-inflammatory mediators from microglial cells, and promoted M2 polarization in vitro, which in turn protected the co-cultured neurons from apoptosis via suppression of the NF-κB and MAPK signalling pathways. Furthermore, daily intraperitoneal injections of 80 mg/kg Rea into a rat model of SCI significantly improved the behavioural and histological indices, promoted M2 microglial polarization, alleviated neuronal apoptosis, and increased motor function recovery. Therefore, Rea is a promising therapeutic option for SCI and should be clinically explored.     

Centipeda minima extract exerts antineuroinflammatory effects via the inhibition of NF-κB signaling pathway

BackgroundCentipeda minima (L.) A.Br. (C. minima) has been used in traditional Chinese herbal medicine to treat nasal allergy, diarrhea, asthma and malaria for centuries. Recent pharmacological studies have demonstrated that the ethanol extract of C. minima (ECM) and several active components possess anti-bacterial, anti-arthritis and anti-inflammatory properties. However, the effects of ECM on neuroinflammation and the underlying mechanisms have never been reported.PurposeThe study aimed to examine the potential inhibitory effects of ECM on neuroinflammation and illustrate the underlying mechanisms.MethodsHigh performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was performed to qualify the major components of ECM; BV2 and primary microglial cells were used to examine the anti-inflammatory activity of ECM in vitro. To evaluate the anti-inflammatory effects of ECM in vivo, the mice were orally administrated with ECM (100, 200 mg•kg⁻¹•d⁻¹) for 2 days before cotreatment with LPS (2 mg•kg⁻¹•d⁻¹, ip) for an additional 3 days. The mice were sacrificed the day after the last treatment and the hippocampus was dissected for further experiments. The expression of inflammatory proteins and the activation of microglia were respectively detected by real-time PCR, ELISA, Western blotting and immunofluorescence.ResultsHPLC-MS/MS analysis confirmed and quantified seven chemicals in ECM. In BV2 and primary microglial cells, ECM inhibited the LPS-induced production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), thus protecting HT22 neuronal cells from inflammatory damage. Furthermore, ECM inhibited the LPS-induced activation of NF-κB signaling pathway and subsequently attenuated the induction of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), NADPH oxidase 2 (NOX2) and NADPH oxidase 4 (NOX4), leading to the decreased production of nitrite oxide, prostaglandin E₂ (PGE₂) and reactive oxygen species (ROS). In an LPS-induced neuroinflammatory mouse model, ECM was found to exert anti-inflammatory activity by decreasing the production of proinflammatory mediators, inhibiting the phosphorylation of NF-κB, and reducing the expression of COX2, iNOS, NOX2 and NOX4 in the hippocampal tissue. Moreover, LPS-induced microglial activation was markedly attenuated in the hippocampus, while ECM at a high dose possesses a stronger anti-inflammatory activity than the positive drug dexamethansone (DEX).ConclusionThese findings demonstrate that ECM exerts antineuroinflammatory effects via attenuating the activation of NF-κB signaling pathway and inhibiting the production of proinflammatory mediators both in vitro and in vivo. C. minima might become a novel phytomedicine to treat neuroinflammatory diseases.     

Galectin-3 deficiency protects lipopolysaccharide-induced chondrocytes injury via regulation of TLR4 and PPAR-γ-mediated NF-κB signaling pathway

The aim of the present study was to identify the functional role of galectin-3 (Gal-3) in lipopolysaccharide (LPS)-induced injury in ATDC5 cells and to explore the probable molecular mechanisms. Here, we identified that LPS is sufficient to enhance the expression of Gal-3 in ATDC5 cells. In addition, repression of Gal-3 obviously impeded LPS-stimulated inflammation damage as exemplified by a reduction in the release of inflammatory mediators interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, as well as the production of nitric oxide and prostaglandin E2 (PGE2) concomitant with the downregulation of matrix metalloproteinases (MMP)-13 and MMP-3 expression in ATDC5 cells after LPS administration. Moreover, ablation of Gal-3 dramatically augmented cell ability and attenuated cell apoptosis accompanied by an increase in the expression of antiapoptotic protein Bcl-2 and a decrease in the expression of proapoptotic protein Bax and caspase-3 in ATDC5 cells subjected with LPS. Importantly, we observed that forced expression of TLR4 or blocked PPAR-γ with the antagonist GW9662 effectively abolished Gal-3 inhibition–mediated anti-inflammatory and antiapoptosis effects triggered by LPS. Mechanistically, depletion of Gal-3 prevents the NF-κB signaling pathway. Taken together, these findings indicated that the absence of Gal-3 exerted chondroprotective properties dependent on TLR4 and PPAR-γ-mediated NF-κB signaling, indicating that Gal-3 functions as a protector in the development and progression of osteoarthritis.     

Tat-DJ-1 enhances cell survival by inhibition of oxidative stress,NF-κB and MAPK activation in HepG2 cells

Objectives

To identify the protective effect of DJ-1 protein against oxidative stress-induced HepG2 cell death, we used cell-permeable wild type (WT) and a mutant (C106A Tat-DJ-1) protein.

Results

By using western blotting and fluorescence microscopy, we observed WT and C106A Tat-DJ-1 proteins were efficiently transduced into HepG2 cells. Transduced WT Tat-DJ-1 proteins increased cell survival and protected against DNA fragmentation and intracellular ROS generation levels in H₂O₂-exposed HepG2 cells. At the same time, transduced WT Tat-DJ-1 protein significantly inhibited NF-κB and MAPK (JNK and p38) activation as well as regulated the Bcl-2 and Bax expression levels. However, C106A Tat-DJ-1 protein did not show any protective effect against cell death responses in H₂O₂-exposed HepG2 cells.

Conclusions

Oxidative stress-induced HepG2 cell death was significantly reduced by transduced WT Tat-DJ-1 protein, not by C106A Tat-DJ-1 protein. Thus, transduction of WT Tat-DJ-1 protein could be a novel strategy for promoting cell survival in situations of oxidative stress-induced HepG2 cell death.

     

PPARα agonist fenofibrate protects the kidney from hypertensive injury in spontaneously hypertensive rats via inhibition of oxidative stress and MAPK activity

Oxidative stress has been shown to play an important role in the development of hypertensive renal injury. Peroxisome proliferator-activated receptors α (PPARα) has antioxidant effect. In this study, we demonstrated that fenofibrate significantly reduced proteinuria, inflammatory cell recruitment and extracellular matrix (ECM) proteins deposition in the kidney of SHRs without apparent effect on blood pressure. To investigate the mechanisms involved, we found that fenofibrate treatment markedly reduced oxidative stress accompanied by reduced activity of renal NAD(P)H oxidase, increased activity of Cu/Zn SOD, and decreased phosphorylation of p38MAPK and JNK in the kidney of SHRs.Taken together, fenofibrate treatment can protect against hypertensive renal injury without affecting blood pressure by inhibiting inflammation and fibrosis via suppression of oxidative stress and MAPK activity.     

Mechanical stress protects against osteoarthritis via regulation of the AMPK/NF-κB signaling pathway

Mechanical stress plays a key role in regulating cartilage degradation in osteoarthritis (OA). The aim of this study was to evaluate the effects and mechanisms of mechanical stress on articular cartilage. A total of 80 male Sprague-Dawley rats were randomly divided into eight groups (n = 10 for each group): control group (CG), OA group (OAG), and CG or OAG subjected to low-, moderate-, or high-intensity treadmill exercise (CL, CM, CH, OAL, OAM, and OAH, respectively). Chondrocytes were obtained from the knee joints of rats; they were cultured on Bioflex 6-well culture plates and subjected to different durations of cyclic tensile strain (CTS) with or without exposure to interleukin-1β (IL-1β). The results of the histological score, immunohistochemistry, enzyme-linked immunosorbent assay, and western-blot analyses indicated that there were no differences between CM and CG, but OAM showed therapeutic effects compared with OAG. However, CH and OAH experienced more cartilage damage than CG and OAG, respectively. CTS had no therapeutic effects on collagen II of normal chondrocytes, which is consistent with findings after treadmill exercise. However, CTS for 4 hr could alleviate the chondrocyte damage induced by IL-1β by activating AMP-activated protein kinase (AMPK) phosphorylation and suppressing nuclear translocation of nuclear factor (NF)-κB p65. Our findings indicate that mechanical stress had no therapeutic effects on normal articular cartilage and chondrocytes; mechanical stress only caused damage with excessive stimulation. Still, moderate biomechanical stress could reduce sensitization to the inflammatory response of articular cartilage and chondrocytes through the AMPK/NF-κB signaling pathway.     

Dexmedetomidine alleviates lipopolysaccharide-induced acute kidney injury by inhibiting the NLRP3 inflammasome activation via regulating the TLR4/NOX4/NF-κB pathway

Dexmedetomidine (DEX) prevents kidney damage caused by sepsis, but the mechanism of this effect remains unclear. In this study, the protective molecular mechanism of DEX in lipopolysaccharide (LPS)-induced acute kidney injury was investigated and its potential pharmacological targets from the perspective of inhibiting oxidative stress damage and the nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome activation. Intraperitoneal injection of DEX (30 μg/kg) significantly improved LPS (10 mg/kg) induced renal pathological damage and renal dysfunction. DEX also ameliorated oxidative stress damage by reducing the contents of reactive oxygen species, malondialdehyde and hydrogen peroxide, and increasing the level of glutathione, as well as the activity of superoxide dismutase and catalase. In addition, DEX prevented nuclear factor-kappa B (NF-κB) activation and I-kappa B (IκB) phosphorylation, as well as the expressions of NLRP3 inflammasome-associated protein and downstream IL-18 and IL-1β. The messengerRNA (mRNA) and protein expressions of toll-like receptor 4 (TLR4), NADPH oxidase-4 (NOX4), NF-κB, and NLRP3 were also significantly reduced by DEX. Their expressions were further evaluated by immunohistochemistry, yielding results were consistent with the results of mRNA and protein detection. Interestingly, the protective effects of DEX were reversed by atipamezole-an alpha 2 adrenal receptor (α₂AR) inhibitor, whereas idazoxan-an imidazoline receptor (IR) inhibitor failed to reverse this change. In conclusion, DEX attenuated LPS-induced AKI by inhibiting oxidative stress damage and NLRP3 inflammasome activation via regulating the TLR4/NOX4/NF-κB pathway, mainly acting on the α₂AR rather than IR.     

Astragalus polysaccharides alleviates LPS-induced inflammation via the NF-κB/MAPK signaling pathway

Early weaning usually causes intestinal disorders, enteritis, and diarrhea in young animals and human infants. Astragalus polysaccharides (APS) possesses anti-inflammatory activity. To study the anti-inflammatory mechanisms of APS and its potential effects on intestinal health, we performed an RNA sequencing (RNA-seq) study in lipopolysaccharide (LPS)-stimulated porcine intestinal epithelial cells (IPEC-J2) in vitro. In addition, LPS-stimulated BALB/c mice were used to study the effects of APS on intestinal inflammation in vivo. The results from the RNA-seq analysis show that there were 107, 756, and 5 differentially expressed genes in the control versus LPS, LPS versus LPS+APS, and control versus LPS+APS comparison groups, respectively. The results of Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways play significant roles in the regulation of inflammatory factors and chemokine expression by APS. Further verification of the above two pathways by using western blot and immunofluorescence analysis revealed that the gene expression levels of the phosphorylated p38 MAPK, ERK1/2, and NF-κB p65 were inhibited by APS, while the expression of IκB-α protein was significantly increased (p < .05), indicating that APS inhibits the production of inflammatory factors and chemokines by the inhibition of activation of the MAPK and NF-κB inflammatory pathways induced by LPS stimulation. Animal experiments further demonstrated that prefeeding APS in BALB/c mice can alleviate the expression of the jejunal inflammatory factors interleukin 6 (IL-6), IL-Iβ, and tumor necrosis factor-α induced by LPS stimulation and improve jejunal villus morphology.     

UCP4 is a target effector of the NF-κB c-Rel prosurvival pathway against oxidative stress

Mitochondrial uncoupling protein-4 (UCP4) enhances neuronal survival in 1-methyl-4-phenylpyridinium (MPP(+)) toxicity by suppressing oxidative stress and preserving intracellular ATP and mitochondrial membrane potential (MMP). NF-κB regulates neuronal viability via its complexes, p65 mediating cell death and c-Rel promoting cell survival. We reported previously that NF-κB mediates UCP4 neuroprotection against MPP(+) toxicity. Here, we investigated its link with the NF-κB c-Rel prosurvival pathway in alleviating mitochondrial dysfunction and oxidative stress. We overexpressed a c-Rel-encoding plasmid in SH-SY5Y cells and showed that c-Rel overexpression induced NF-κB activity without affecting p65 level. Overexpression of c-Rel increased UCP4 promoter activity and protein expression. Electrophoretic mobility shift assay showed that H(2)O(2) increased NF-κB binding to the UCP4 promoter and that NF-κB complexes were composed of p50/p50 and p50/c-Rel dimers. Under H(2)O(2)-induced oxidative stress, UCP4 knockdown significantly increased superoxide levels, decreased reduced glutathione (GSH) levels, and increased oxidized glutathione levels, compared to controls. UCP4 expression induced by c-Rel overexpression significantly decreased superoxide levels and preserved GSH levels and MMP under similar stress. These protective effects of c-Rel overexpression in H(2)O(2)-induced oxidative stress were significantly reduced after UCP4 knockdown, indicating that UCP4 is a target effector gene of the NF-κB c-Rel prosurvival pathway to mitigate the effects of oxidative stress.     

Reduning injection ameliorates paraquat-induced acute lung injury by regulating AMPK/MAPK/NF-κB signaling

Reduning injection (RDN), a patented Chinese medicine, is broadly used for common cold and lung infection in clinic, but the mechanism underlying its effects on inflammation-related pulmonary injury remains unclear. Paraquat (PQ, bolus 15 mg/kg dose, ip) was administered for acute lung injury induction in mice, which were orally administered dexamethasone (2 mg/kg) or RDN (50 and 100 mg/kg/day) for 5 days. After treatment, plasma and lung tissue samples from the euthanized animals were obtained and analyzed by histological, biochemical and immunoblot assays. Histological observation demonstrated RDN alleviated PQ-induced lung damage. Meanwhile, RDN suppressed myeloperoxidase (MPO) activity, reduced the wet/dry (W/D) ratio and decreased the amounts of total leukocytes and neutrophils. Treatment also markedly decreased the amounts of malondialdehyde, MPO, and inflammatory cytokines while increasing superoxide dismutase activity in comparison with the PQ group. In immunoblot, RDN blocked the phosphorylation levels of adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK), JNK, ERK, p38, inhibitor of nuclear factor κB kinase and nuclear factor-κB (NF-κB) in lung tissue specimens in PQ-challenged animals, which was further verified in vitro. The above data indicated protective effects for RDN in PQ-induced lung damage, possibly through inhibition of the AMPK/MAPK/NF-κB pathway.