1.Interferon-λ1 improves glucocorticoid resistance caused by respiratory syncytial virus by regulating the p38 mitogen-activated protein kinase signaling pathway.
Li PENG ; Yao LIU ; Fang-Cai LI ; Xiao-Fang DING ; Xiao-Juan LIN ; Tu-Hong YANG ; Li-Li ZHONG
Chinese Journal of Contemporary Pediatrics 2025;27(8):1011-1016
OBJECTIVES:
To investigate the effect of interferon-λ1 (IFN-λ1) on glucocorticoid (GC) resistance in human bronchial epithelial cells (HBECs) stimulated by respiratory syncytial virus (RSV).
METHODS:
HBECs were divided into five groups: control, dexamethasone, IFN-λ1, RSV, and RSV+IFN-λ1. CCK-8 assay was used to measure the effect of different concentrations of IFN-λ1 on the viability of HBECs, and the sensitivity of HBECs to dexamethasone was measured in each group. Quantitative real-time PCR was used to measure the mRNA expression levels of p38 mitogen-activated protein kinase (p38 MAPK), glucocorticoid receptor (GR), and MAPK phosphatase-1 (MKP-1). Western blot was used to measure the protein expression level of GR in cell nucleus and cytoplasm, and the nuclear/cytoplasmic ratio of GR was calculated.
RESULTS:
At 24 and 72 hours, the proliferation activity of HBECs increased with the increase in IFN-λ1 concentration in a dose- and time-dependent manner (P˂0.05). Compared with the RSV group, the RSV+IFN-λ1 group had significant reductions in the half-maximal inhibitory concentration of dexamethasone and the mRNA expression level of p38 MAPK (P<0.05), as well as significant increases in the mRNA expression levels of GR and MKP-1, the level of GR in cell nucleus and cytoplasm, and the nuclear/cytoplasmic GR ratio (P<0.05).
CONCLUSIONS
IFN-λ1 can inhibit the p38 MAPK pathway by upregulating MKP-1, promote the nuclear translocation of GR, and thus ameliorate GC resistance in HBECs.
Humans
;
p38 Mitogen-Activated Protein Kinases/genetics*
;
Glucocorticoids/pharmacology*
;
Receptors, Glucocorticoid/analysis*
;
Dual Specificity Phosphatase 1/physiology*
;
Dexamethasone/pharmacology*
;
Drug Resistance/drug effects*
;
Respiratory Syncytial Viruses
;
Interferons/pharmacology*
;
MAP Kinase Signaling System/drug effects*
;
Epithelial Cells/drug effects*
;
Signal Transduction/drug effects*
;
Cells, Cultured
2.Leptin-mediated ERK Signaling Pathway Promotes the Transformation of Rat Alveolar Type II Epithelial Cells Induced by Yunnan Tin Mine Dust.
Xiong HU ; Cong YAN ; Yu ZHANG ; Guiyun LI ; Zheyan ZHOU ; Yonghua RUAN ; Shiyue LIU ; Li BIAN
Chinese Journal of Lung Cancer 2023;26(10):732-740
BACKGROUND:
Currently, a significant number of miners are involved in mining operations at the Gejiu tin mine in Yunnan. This occupational setting is associated with exposure to dust particles, heavy metals, polycyclic aromatic hydrocarbons, and radioactive radon, thereby significantly elevating the risk of lung cancer. This study aims to investigate the involvement of leptin-mediated extracellular regulated protein kinase (ERK) signaling pathway in the malignant transformation of rat alveolar type II epithelial cells induced by Yunnan tin mine dust.
METHODS:
Immortalized rat alveolar cells type II (RLE-6TN) cells were infected with Yunnan tin mine dust at a concentration of 200 μg/mL for nine consecutive generations to establish the infected cell model, which was named R₂₀₀ cells. The cells were cultured normally, named as R cells. The expression of leptin receptor in both cell groups was detected using the Western blot method. The optimal concentration of leptin and mitogen-activated protein kinase kinase (MEK) inhibitor (U0126) on R₂₀₀ cells was determined using the MTT method. Starting from the 20th generation, the cells in the R group were co-cultured with leptin, while the cells in the R₂₀₀ group were co-cultured with the MEK inhibitor U0126. The morphological alterations of the cells in each group were visualized utilizing hematoxylin-eosin staining. Additionally, concanavalin A (ConA) was utilized to detect any morphological differences, and an anchorage-independent growth assay was conducted to assess the malignant transformation of the cells. The changes in the ERK signaling pathway in epithelial cells after the action of leptin were detected using the Western blot method.
RESULTS:
Both the cells in the R group and R₂₀₀ group express leptin receptor OB-R. Compared to the R₂₀₀ group, the concentration of leptin at 100 ng/mL shows the most significant pro-proliferation effect. The proliferation of R₂₀₀ cells infected with the virus is inhibited by 30 μmol/L U0126, and a statistically significant divergence was seen when compared to the control group (P<0.05). Starting from the 25th generation, the cell morphology of the leptin-induced R₂₀₀ group (R₂₀₀L group) underwent changes, leading to malignant transformation observed at the 30th generation. The characteristics of malignant transformation became evident by the 40th generation in the R₂₀₀L group. In contrast, the other groups showed agglutination of P40 cells, and the speed of cell aggregation increased with an increase in ConA concentration. Notably, the R₂₀₀L group exhibited faster cell aggregation compared to the U0126-induced R₂₀₀ (R₂₀₀LU) group. Additionally, the cells in the R₂₀₀L group were capable of forming clones starting from P30, with a colony formation rate of 2.25‰±0.5‰. However, no clonal colonies were observed in the R₂₀₀LU group and R₂₀₀ group. The expression of phosphorylated extracellular signal-regulated kinase (pERK) was enhanced in cells of the R₂₀₀L group. However, when the cells in the R₂₀₀L group were treated with U0126, a blocking agent, the phosphorylation level of pERK decreased.
CONCLUSIONS
Leptin can promote the malignant transformation of lung epithelial cells infected by mine dust, and the ERK signaling pathway may be necessary for the transformation of alveolar type II epithelial cells induced by Yunnan tin mine dust.
Rats
;
Animals
;
Alveolar Epithelial Cells/pathology*
;
Dust
;
Tin/adverse effects*
;
Lung Neoplasms/pathology*
;
Leptin/adverse effects*
;
Receptors, Leptin
;
China
;
Signal Transduction
;
Epithelial Cells/pathology*
;
Mitogen-Activated Protein Kinase Kinases/adverse effects*
3.Cytokine receptor-like factor 1 (CRLF1) promotes cardiac fibrosis via ERK1/2 signaling pathway.
Shenjian LUO ; Zhi YANG ; Ruxin CHEN ; Danming YOU ; Fei TENG ; Youwen YUAN ; Wenhui LIU ; Jin LI ; Huijie ZHANG
Journal of Zhejiang University. Science. B 2023;24(8):682-697
Cardiac fibrosis is a cause of morbidity and mortality in people with heart disease. Anti-fibrosis treatment is a significant therapy for heart disease, but there is still no thorough understanding of fibrotic mechanisms. This study was carried out to ascertain the functions of cytokine receptor-like factor 1 (CRLF1) in cardiac fibrosis and clarify its regulatory mechanisms. We found that CRLF1 was expressed predominantly in cardiac fibroblasts. Its expression was up-regulated not only in a mouse heart fibrotic model induced by myocardial infarction, but also in mouse and human cardiac fibroblasts provoked by transforming growth factor-β1 (TGF-β1). Gain- and loss-of-function experiments of CRLF1 were carried out in neonatal mice cardiac fibroblasts (NMCFs) with or without TGF-β1 stimulation. CRLF1 overexpression increased cell viability, collagen production, cell proliferation capacity, and myofibroblast transformation of NMCFs with or without TGF-β1 stimulation, while silencing of CRLF1 had the opposite effects. An inhibitor of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway and different inhibitors of TGF-β1 signaling cascades, comprising mothers against decapentaplegic homolog (SMAD)-dependent and SMAD-independent pathways, were applied to investigate the mechanisms involved. CRLF1 exerted its functions by activating the ERK1/2 signaling pathway. Furthermore, the SMAD-dependent pathway, not the SMAD-independent pathway, was responsible for CRLF1 up-regulation in NMCFs treated with TGF-β1. In summary, activation of the TGF-β1/SMAD signaling pathway in cardiac fibrosis increased CRLF1 expression. CRLF1 then aggravated cardiac fibrosis by activating the ERK1/2 signaling pathway. CRLF1 could become a novel potential target for intervention and remedy of cardiac fibrosis.
Animals
;
Humans
;
Mice
;
Disease Models, Animal
;
Fibroblasts/metabolism*
;
Fibrosis
;
MAP Kinase Signaling System
;
Mitogen-Activated Protein Kinase 3/metabolism*
;
Myocardial Infarction/metabolism*
;
Receptors, Cytokine/metabolism*
;
Signal Transduction
;
Transforming Growth Factor beta1/pharmacology*
4.Scaffold protein MAPK8IP2 expression is a robust prognostic factor in prostate cancer associated with AR signaling activity.
Jian HUANG ; Wang LIU ; Bi-Yun LIN ; Jean C LI ; Jane LU ; Ben-Yi LI
Asian Journal of Andrology 2023;25(2):198-207
Mitogen-activated protein kinase-8-interacting protein 2 (MAPK8IP2) is a scaffold protein that modulates MAPK signal cascades. Although MAPK pathways were heavily implicated in prostate cancer progression, the regulation of MAPK8IP2 expression in prostate cancer is not yet reported. We assessed MAPK8IP2 gene expression in prostate cancer related to disease progression and patient survival outcomes. MAPK8IP2 expression was analyzed using multiple genome-wide gene expression datasets derived from The Cancer Genome Atlas (TCGA) RNA-sequence project and complementary DNA (cDNA) microarrays. Multivariable Cox regressions and log-rank tests were used to analyze the overall survival outcome and progression-free interval. MAPK8IP2 protein expression was evaluated using the immunohistochemistry approach. The quantitative PCR and Western blot methods analyzed androgen-stimulated MAPK8IP2 expression in LNCaP cells. In primary prostate cancer tissues, MAPK8IP2 mRNA expression levels were significantly higher than those in the case-matched benign prostatic tissues. Increased MAPK8IP2 expression was strongly correlated with late tumor stages, lymph node invasion, residual tumors after surgery, higher Gleason scores, and preoperational serum prostate-specific antigen (PSA) levels. MAPK8IP2 upregulation was significantly associated with worse overall survival outcomes and progression-free intervals. In castration-resistant prostate cancers, MAPK8IP2 expression strongly correlated with androgen receptor (AR) signaling activity. In cell culture-based experiments, MAPK8IP2 expression was stimulated by androgens in AR-positive prostate cancer cells. However, MAPK8IP2 expression was blocked by AR antagonists only in androgen-sensitive LNCaP but not castration-resistant C4-2B and 22RV1 cells. These results indicate that MAPK8IP2 is a robust prognostic factor and therapeutic biomarker for prostate cancer. The potential role of MAPK8IP2 in the castration-resistant progression is under further investigation.
Male
;
Humans
;
Androgens/therapeutic use*
;
Receptors, Androgen/genetics*
;
Prognosis
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Cell Line, Tumor
;
Prostatic Neoplasms/pathology*
;
Prostatic Neoplasms, Castration-Resistant/drug therapy*
;
Gene Expression Regulation, Neoplastic
5.Advances in N-methyl-D-aspartate Receptor Signaling Pathway and Mechanism of the Pathway-mediated Apoptosis.
Yi-Xiao HAN ; Ya-Zhu HOU ; Hai-Feng YAN ; Shuai WANG ; Xian-Liang WANG ; Jing-Yuan MAO
Acta Academiae Medicinae Sinicae 2022;44(1):149-157
N-methyl-D-aspartate receptor (NMDAR),an important ionic glutamate receptor and a ligand and voltage-gated ion channel characterized by complex composition and functions and wide distribution,plays a key role in the pathological and physiological process of diseases or stress states.NMDAR can mediate apoptosis through different pathways such as mitochondrial and endoplasmic reticulum damage,production of reactive oxygen species and peroxynitrite,and activation of mitogen-activated protein kinase and calpain.This paper reviews the structure,distribution,and biological characteristics of NMDAR and the mechanisms of NMDAR-mediated apoptosis.
Apoptosis
;
Humans
;
Mitogen-Activated Protein Kinases/metabolism*
;
Reactive Oxygen Species/metabolism*
;
Receptors, N-Methyl-D-Aspartate/metabolism*
;
Signal Transduction
6.Development and functional verification of CAR-T cells targeting CLL-1.
Xiao CHAI ; Xin JIN ; Min Feng ZHAO
Chinese Journal of Hematology 2022;43(2):102-106
Objective: To explore the development of a CAR-T cells targeting CLL-1 and verify its function. Methods: The expression levels of CLL-1 targets in cell lines and primary cells were detected by flow cytometry. A CLL-1 CAR vector was constructed, and the corresponding lentivirus was prepared. After infection and activation of T cells, CAR-T cells targeting CLL-1 were produced and their function was verified in vitro and in vivo. Results: CLL-1 was expressed in acute myeloid leukemia (AML) cell lines and primary AML cells. The transduction rate of the prepared CAR T cells was 77.82%. In AML cell lines and AML primary cells, CLL-1-targeting CAR-T cells significantly and specifically killed CLL-1-expressing cells. Compared to untransduced T cells, CAR-T cells killed target cells and secreted inflammatory cytokines, such as interleukin-6 and interferon-γ, at significantly higher levels (P<0.001) . In an in vivo human xenograft mouse model of AML, CLL-1 CAR-T cells also exhibited potent antileukemic activity and induced prolonged mouse survival compared with untransduced T cells [not reached vs 22 days (95%CI 19-24 days) , P=0.002]. Conclusion: CAR-T cells targeting CLL-1 have been successfully produced and have excellent functions.
Animals
;
Cell Line, Tumor
;
Cytokines
;
Humans
;
Immunotherapy, Adoptive
;
Lectins, C-Type
;
Leukemia, Myeloid, Acute/metabolism*
;
Mice
;
Receptors, Mitogen
;
T-Lymphocytes
7.Glycosylation, glycan receptors recognition of SARS-CoV-2 and discoveries of glycan inhibitors against SARS-CoV-2.
Weiyan YU ; Yueqiang XU ; Jianjun LI ; Zhimin LI ; Qi WANG ; Yuguang DU
Chinese Journal of Biotechnology 2022;38(9):3157-3172
COVID-19 represents the most serious public health event in the past few decades of the 21st century. The development of vaccines, neutralizing antibodies, and small molecule chemical agents have effectively prevented the rapid spread of COVID-19. However, the continued emergence of SARS-CoV-2 variants have weakened the efficiency of these vaccines and antibodies, which brought new challenges for searching novel anti-SARS-CoV-2 drugs and methods. In the process of SARS-CoV-2 infection, the virus firstly attaches to heparan sulphate on the cell surface of respiratory tract, then specifically binds to hACE2. The S protein of SARS-CoV-2 is a highly glycosylated protein, and glycosylation is also important for the binding of hACE2 to S protein. Furthermore, the S protein is recognized by a series of lectin receptors in host cells. These finding implies that glycosylation plays important roles in the invasion and infection of SARS-CoV-2. Based on the glycosylation pattern and glycan recognition mechanisms of SARS-CoV-2, it is possible to develop glycan inhibitors against COVID-19. Recent studies have shown that sulfated polysaccharides originated from marine sources, heparin and some other glycans display anti-SARS-CoV-2 activity. This review summarized the function of glycosylation of SARS-CoV-2, discoveries of glycan inhibitors and the underpinning molecular mechanisms, which will provide guidelines to develop glycan-based new drugs against SARS-CoV-2.
Antibodies, Neutralizing
;
Glycosylation
;
Heparin
;
Heparitin Sulfate
;
Humans
;
Polysaccharides/chemistry*
;
Receptors, Mitogen/metabolism*
;
SARS-CoV-2
;
Spike Glycoprotein, Coronavirus/metabolism*
;
COVID-19 Drug Treatment
8.Medication law and mechanism of traditional Chinese medicine in prevention and treatment of epidemic diseases: based on traditional Chinese medicine theory of cold pestilence.
Ze-Yu LI ; Er-Wei HAO ; Rui CAO ; Si LIN ; Shu-Ying CHEN ; Xian-Ting HUANG ; Wan-Ru XU ; Xiao-Tao HOU ; Jia-Gang DENG
China Journal of Chinese Materia Medica 2022;47(17):4765-4777
Epidemic diseases have caused huge harm to the society. Traditional Chinese medicine(TCM) has made great contributions to the prevention and treatment of them. It is of great reference value for fighting diseases and developing drugs to explore the medication law and mechanism of TCM under TCM theory. In this study, the relationship between the TCM theory of cold pestilence and modern epidemic diseases was investigated. Particularly, the the relationship of coronavirus disease 2019(COVID-19), severe acute respiratory syndrome(SARS), and influenza A(H1 N1) with the cold pestilence was identified and analyzed. The roles of TCM theory of cold pestilence in preventing and treating modern epidemic diseases were discussed. Then, through data mining and textual research, prescriptions for the treatment of cold pestilence were collected from major databases and relevant ancient books, and their medication laws were examined through analysis of high-frequency medicinals and medicinal pairs, association rules analysis, and cluster analysis. For example, the prescriptions with high confidence levels were identified: "Glycyrrhizae Radix et Rhizoma-Bupleuri Radix-Paeoniae Radix Alba" "Glycyrrhizae Radix et Rhizoma-Pinelliae Rhizoma-Bupleuri Radix", and TCM treatment methods with them were analyzed by clustering analysis to yield the medicinal combinations: "Zingiberis Rhizoma-Aconiti Lateralis Radix Praeparata-Ginseng Radix et Rhizoma" "Poria-Atractylodis Macrocephalae Rhizoma" "Cinnamomi Ramulus-Asari Radix et Rhizoma" "Citri Reticulatae Pericarpium-Perillae Folium" "Pinelliae Rhizoma-Magnoliae Officinalis Cortex-Atractylodis Rhizoma" "Paeoniae Radix Alba-Angelicae Sinensis Radix-Glycyrrhizae Radix et Rhizoma-Bupleuri Radix-Scutellariae Radix-Rhizoma Zingiberis Recens" "Ephedrae Herba-Armeniacae Semen Amarum-Gypsum Fibrosum" "Chuanxiong Rhizoma-Notopterygii Rhizoma et Radix-Angelicae Dahuricae Radix-Platycodonis Radix-Saposhnikoviae Radix". Then, according to the medication law for cold pestilence, the antiviral active components of medium-frequency and high-frequency medicinals were retrieved. It was found that these components exerted the antiviral effect by inhibiting virus replication, regulating virus proteins and antiviral signals, and suppressing protease activity. Based on network pharmacology, the mechanisms of the medicinals against severe acute respiratory syndrome coronavirus(SARS-CoV), 2019 novel coronavirus(2019-nCoV), and H1 N1 virus were explored. It was determined that the key targets were tumor necrosis factor(TNF), endothelial growth factor A(VEGFA), serum creatinine(SRC), epidermal growth factor receptor(EGFR), matrix metalloproteinase 9(MMP9), mitogen-activated protein kinase 14(MAPK14), and prostaglandin-endoperoxide synthase 2(PTGS2), which were involved the mitogen-activated protein kinase(MAPK) pathway, advanced glycation end-products(AGE)-receptor for AGE(RAGE) pathway, COVID-19 pathway, and mTOR pathway. This paper elucidated the medication law and mechanism of TCM for the prevention and treatment of epidemic diseases under the guidance of TCM theory of cold pestilence, in order to build a bridge between the theory and modern epidemic diseases and provide reference TCM methods for the prevention and treatment of modern epidemic diseases and ideas for the application of data mining to TCM treatment of modern diseases.
Aconitum
;
Antiviral Agents
;
COVID-19/epidemiology*
;
Calcium Sulfate
;
Communicable Disease Control
;
Communicable Diseases/virology*
;
Creatinine
;
Cyclooxygenase 2
;
Drugs, Chinese Herbal/therapeutic use*
;
Endothelial Growth Factors
;
Epidemics/prevention & control*
;
ErbB Receptors
;
Humans
;
Matrix Metalloproteinase 9
;
Medicine, Chinese Traditional
;
Mitogen-Activated Protein Kinase 14
;
Pinellia
;
SARS-CoV-2
;
TOR Serine-Threonine Kinases
;
Tumor Necrosis Factors
;
COVID-19 Drug Treatment
9.Mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination in treatment of bronchial asthma based on network pharmacology and experimental verification.
Bei-Bei ZHANG ; Meng-Nan ZENG ; Qin-Qin ZHANG ; Ru WANG ; Ju-Fang JIA ; Peng-Li GUO ; Meng LIU ; Wei-Sheng FENG ; Xiao-Ke ZHENG
China Journal of Chinese Materia Medica 2022;47(18):4996-5007
This study aims to investigate mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination(MT) in the treatment of bronchial asthma based on network pharmacology and in vivo experiment, which is expected to lay a theoretical basis for clinical application of the combination. First, the potential targets of MT in the treatment of bronchial asthma were predicted based on network pharmacology, and the "Chinese medicine-active component-target-pathway-disease" network was constructed, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the potential targets. Molecular docking was used to determine the binding activity of key candidate active components to hub genes. Ovalbumin(OVA, intraperitoneal injection for sensitization and nebulization for excitation) was used to induce bronchial asthma in rats. Rats were classified into control group(CON), model group(M), dexamethasone group(DEX, 0.075 mg·kg~(-1)), and MT(1∶1.5) group. Hematoxylin and eosin(HE), Masson, and periodic acid-Schiff(PAS) staining were performed to observe the effect of MT on pathological changes of lungs and trachea and goblet cell proliferation in asthma rats. The levels of transforming growth factor(TGF)-β1, interleukin(IL)6, and IL10 in rat serum were detected by enzyme-linked immunosorbent assay(ELISA), and the mRNA and protein levels of mitogen-activated protein kinase 8(MAPK8), cyclin D1(CCND1), IL6, epidermal growth factor receptor(EGFR), phosphatidylinositol 3-kinase(PI3 K), and protein kinase B(Akt) by qRT-PCR and Western blot. Network pharmacology predicted that MAPK8, CCND1, IL6, and EGFR were the potential targets of MT in the treatment of asthma, which may be related to PI3 K/Akt signaling pathway. Quercetin and β-sitosterol in MT acted on a lot of targets related to asthma, and molecular docking results showed that quercetin and β-sitosterol had strong binding activity to MAPK, PI3 K, and Akt. In vivo experiment showed that MT could effectively alleviate the symptoms of OVA-induced asthma rats, improve the pathological changes of lung tissue, reduce the production of goblet cells, inhibit the inflammatory response of asthma rats, suppress the expression of MAPK8, CCND1, IL6, and EGFR, and regulate the PI3 K/Akt signaling pathway. Therefore, MT may relieve the symptoms and inhibit inflammation of asthma rats by regulating the PI3 K/Akt signaling pathway, and quercetin and β-sitosterol are the candidate active components.
Animals
;
Asthma/drug therapy*
;
Cyclin D1
;
Dexamethasone/adverse effects*
;
Drug Combinations
;
Drugs, Chinese Herbal/therapeutic use*
;
Eosine Yellowish-(YS)/adverse effects*
;
Ephedra
;
ErbB Receptors
;
Hematoxylin/therapeutic use*
;
Interleukin-10
;
Interleukin-6
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Molecular Docking Simulation
;
Network Pharmacology
;
Ovalbumin/adverse effects*
;
Periodic Acid/adverse effects*
;
Phosphatidylinositol 3-Kinases
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Quercetin
;
RNA, Messenger
;
Rats
10.Activation of cannabinoid receptor 2 alleviates acute lung injury in rats with lipopolysaccharide-induced sepsis.
Hui Wen KANG ; Shou Fang JIANG ; Qian SONG ; Yi Li ZHANG
Journal of Southern Medical University 2022;42(9):1374-1380
OBJECTIVE:
To investigate the protective effect of cannabinoid receptor 2 (CB2) activation against acute lung injury in rats with lipopolysaccharide (LPS)-induced sepsis and explore the underlying mechanism.
METHODS:
Forty-eight SD rats were randomly assigned into control group, model group, CB2 agonist group and P38 MAPK inhibitor group (n=12). In the latter 3 groups, the rats received intraperitoneal injection of LPS to induce sepsis, and the control rats were given saline injection. In CB2 agonist group, JWH133 (3 mg/kg) was injected intraperitoneally 30 min before LPS injection; in P38 MAPK inhibitor group, the rats received intraperitoneal injection of SB203580 (5 mg/kg) 30 min prior to JWH133 injection. The changes in lung histopathology, water content, fluid clearance rate, inflammatory factors, pulmonary expressions of CB2 and tight junctionrelated genes, and phosphorylation of P38 MAPK in the lung tissues were examined.
RESULTS:
The rat models of sepsis showed severe damage of alveolar structures with significantly decreased fluid clearance rate, lowered pulmonary expressions of CB2, occludin and ZO-1 mRNA and proteins, increased water content in the lung tissue, and increased phosphorylation level of P38 MAPK and TNF-α and IL-1β levels in lung lavage fluid (all P < 0.05). Treatment with JWH133 improved alveolar pathology in the septic rats, but there was still inflammatory infiltration; lung tissue water content, phosphorylation of P38 MAPK, and TNF-α and IL-1β levels in lung lavage fluid were all significantly decreased, and the fluid clearance rate, pulmonary expressions of CB2, occludin and ZO-1 were significantly increased (all P < 0.05). Additional treatment with SB203580 resulted in further improvements of alveolar pathologies, lowered phosphorylation levels of P38 MAPK in the lung tissue and TNF-α and IL-1β levels in lung lavage fluid, and increased the protein expressions of occludin and ZO-1 (P < 0.05) without causing significant changes in mRNA and protein expression of CB2 (P > 0.05).
CONCLUSION
In rats with LPS-induced sepsis, activation of CB2 can inhibit the p38 MAPK signaling pathway, reduce the release of inflammatory factors in the lung tissues, promote tight junction protein expressions, and thus offer protection against acute lung injury.
Acute Lung Injury/metabolism*
;
Animals
;
Cannabinoids
;
Lipopolysaccharides/adverse effects*
;
Lung/pathology*
;
Occludin/metabolism*
;
RNA, Messenger/metabolism*
;
Rats
;
Rats, Sprague-Dawley
;
Receptor, Cannabinoid, CB2
;
Receptors, Cannabinoid/metabolism*
;
Sepsis/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Water/metabolism*
;
p38 Mitogen-Activated Protein Kinases/metabolism*

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