OBJECTIVE: To investigate the intervention of melatonin (MT) in the expression of circadian genes in patients with pulmonary fibrosis and to analyze the mechanism by which it alleviates the progression of pulmonary fibrosis. METHODS: By utilizing the Gene Expression Omnibus (GEO) database, we identified differentially expressed circadian genes between patients with pulmonary fibrosis and controls. We analyzed the correlation between circadian genes and pulmonary function as well as genes related to pulmonary fibrosis. A bleomycin-induced mouse model of pulmonary fibrosis (BLM group) was constructed to observe the expression differences of PER2 and CRY2 by sequencing and immunohistochemical staining in the BLM group and after MT intervention (BLM+MT group). Hematoxylin and eosin (HE) staining and Masson staining were used to observe the effects of MT on fibrosis. We used Western blot to detect the expression of P-smad2/3 in lung epithelial cells induced by transforming growth factor β (TGF-β). Reverse transcription quantitative real-time PCR technology was employed to investigate the rhythmic expression changes of circadian genes in the control group, TGF-β group, and TGF-β+MT group. Finally, luzindole, a MT receptor antagonist, was used to intervene in TGF-β+MT group, and Western blot was used to explore the receptor dependence of MT in alleviating TGF-β-induced epithelial-mesenchymal transition. RESULTS: (1) Analysis of the GEO dataset (GSE) revealed a negative correlation between circadian genes PER2 and CRY2 and the expression of TGF-β, and a positive correlation with pulmonary function indicators in patients. (2) Transcriptome sequencing analysis of lung tissue in BLM group found that the expression of PER2 and CRY2 was significantly reduced compared with the normal group. Histopathological staining results showed that the lung tissue structure of the normal group was intact and clear, with thin alveolar septa; in the BLM group, there was a large increase in collagen fibers and disordered alveolar structure; compared with the BLM group, the BLM+MT group had reduced collagen fiber proliferation and inflammatory cell infiltration; the expression of PER2 and CRY2 in the BLM group was lower than in the normal group, and the expression in the BLM+MT group was increased compared with the BLM group. (3) In vitro lung epithelial cell experiments with TGF-β intervention showed that compared with the control group, the expression of P-smad2/3 increased in the TGF-β group, and MT intervention inhibited the inducing effect of TGF-β on P-smad2/3, while intervention with the MT receptor antagonist reversed this phenomenon. The results indicated that MT could inhibit the activation of the TGF-β pathway, and this process was dependent on MT receptors. (4) The 48-hour rhythm experiment in lung epithelial cells showed that the mRNA rhythm of PER2 and CRY2 in the TGF-β+MT group was close to 24 hours and showed a trend towards restoring the rhythm of the control group, while the addition of the MT receptor blocker tended to make the rhythm duration and amplitude of both groups approach that of the TGF-β group. CONCLUSION MT, by binding to its receptors, can restore the periodic expression of the circadian genes PER2 and CRY2, thereby inhibiting the activation of the TGF-β classical pathway and suppressing the pathological process of epithelial-mesenchymal transition in pulmonary fibrosis. This finding provides new molecular targets and potential therapeutic strategies for the treatment of pulmonary fibrosis.
Melatonin/pharmacology* ; Animals ; Mice ; Pulmonary Fibrosis/chemically induced* ; Bleomycin ; Humans ; Transforming Growth Factor beta/metabolism* ; Period Circadian Proteins/metabolism* ; Smad3 Protein/genetics* ; Disease Models, Animal ; Lung/pathology* ; Cryptochromes/metabolism* ; Smad2 Protein/genetics* ; Epithelial Cells/metabolism* ; Mice, Inbred C57BL

OBJECTIVE: To investigate the effects of Yiqi Huayu Hutan decoction on pulmonary fibrosis of rats which induced by bleomycin. METHODS: The rat model of pulmonary fibrosis was induced by intratracheal injection of bleomycin hydrochloride (5 mg/kg). Sixty SD rats were randomly divided into the normal group (group N), the model group (group M), the positive control group (group Y), group of low concentration (group LC), group of medium concentration (group MC) and group of high concentration of Yiqi Huayu Hutan decoction (group HC). After 4 weeks, the experimental groups were treated with low concentration decoction, medium concentration decoction and high concentration decoction respectively, and the Y group was treated with hydrocortisone acetate, the Group N and group M were treated with saline by intragastric administration. Twelve weeks later, rats were killed and the pathomorphism of pulmonary tissues of each group was observed by HE staining and Masson staining. Further, the expressions of transforming growth factor-β1(TGF-β1), Snail1, E-cadherin and Fibronectin in pulmonary tissues of each group were detected by qTR-PCR and Western blot. RESULTS: Compared with the model group, the collagen sediment in the interstitial was reduced in the experimental groups, especially in the group of medium concentration, which was observed by HE staining and Masson staining .Compared with the model group, the expressions of TGF-β1, Snail1 and Fibronectin protein in pulmonary tissues of the treatment groups were decreased in the experimental group, especially in the group of medium concentration, which were detected by qRT-PCR and Western blot. CONCLUSION Yiqi Huayu Hutan decoction can significantly improve the pulmonary fibrosis which is induced by bleomycin, and the mechanism is related to the inhibition of the expression of TGF-β/Snail pathway of transcription TGF-β1.
Animals ; Bleomycin ; Cadherins ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Fibronectins ; metabolism ; Idiopathic Pulmonary Fibrosis ; chemically induced ; drug therapy ; Lung ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Snail Family Transcription Factors ; metabolism ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVEThe effect of the silica nanoparticles (SNs) on lungs injury in rats was investigated to evaluate the toxicity and possible mechanisms for SNs.

METHODSMale Wistar rats were instilled intratracheally with 1 mL of saline containing 6.25, 12.5, and 25.0 mg of SNs or 25.0 mg of microscale SiO2 particles suspensions for 30 d, were then sacrificed. Histopathological and ultrastructural change in lungs, and chemical components in the urine excretions were investigated by light microscope, TEM and EDS. MDA, NO and hydroxyproline (Hyp) in lung homogenates were quantified by spectrophotometry. Contents of TNF-α, TGF-β1, IL-1β, and MMP-2 in lung tissue were determined by immunohistochemistry staining.

RESULTSThere is massive excretion of Si substance in urine. The SNs lead pulmonary lesions of rise in lung/body coefficients, lung inflammation, damaged alveoli, granuloma nodules formation, and collagen metabolized perturbation, and lung tissue damage is milder than those of microscale SiO2 particles. The SNs also cause increase lipid peroxidation and high expression of cytokines.

CONCLUSIONThe SNs result into pulmonary fibrosis by means of increase lipid peroxidation and high expression of cytokines. Milder effect of the SNs on pulmonary fibrosis comparing to microscale SiO2 particles is contributed to its elimination from urine due to their ultrafine particle size.

Air Pollutants ; toxicity ; Animals ; Dose-Response Relationship, Drug ; Lung ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Nanoparticles ; toxicity ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Specific Pathogen-Free Organisms ; Spectrometry, X-Ray Emission ; Urine ; chemistry

OBJECTIVETo investigate the effects of total flavonoids from astragalus complanatus (FAC) on paraquat poisoning-induced pulmonary fibrosis in rats.

METHODSThe rats were divided into six groups randomly: control group, paraquat group, prednisolone group and FAC low-dose, middle-dose, high-dose group. Pulmonary fibrosis model was replicated by intratracheal injection of paraquat. In the mext day,the rats were treated by intragastric administration once a day. After 28 days, the rats were sacrificed. The lung index and the levels of HYP and T-AOC were measured, and the pathologic changes of the lung tissue were obtained by HE staining. The levels of TGF-β, Smad2, α-SMA protein were analyzed by Western blot.

RESULTSFAC improved the activity of T-AOC in serum and reduced pulmonary index and the content of HYP as well (P<0.05 or P<0.01), the alveolitis and fibrosis extent were attenuated. The expression of Smad2 significantly decreased in groups of FAC low-dose, middle-dose and high-dose (0.31±0.11, 0.45±0.12 and 0.30±0.05) as compared with that of the PQ group (0.85±0.34) (P<0.05). The expression of α-SMA significantly decreased in groups of FAC low-dose, middle-dose and high-dose (0.31±0.11, 0.35±0.07 and 0.32±0.10) as compared with that of the PQ group (0.45±0.08) (P<0.05). The expression of TGF-β significantly decreased in groups of FAC low-dose, middle-dose and high-dose (0.35±0.04, 0.27±0.05 and 0.18±0.04)as compared with that of the PQ group (0.63±0.11) (P<0.05).

CONCLUSIONFAC can alleviate PQ-induced pulmonary fibrosis in rats through inhibiting TGF-β/Smad signaling pathway.

Actins ; metabolism ; Animals ; Astragalus Plant ; chemistry ; Flavonoids ; pharmacology ; Lung ; pathology ; Paraquat ; poisoning ; Phytochemicals ; pharmacology ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; Rats ; Smad2 Protein ; metabolism ; Transforming Growth Factor beta ; metabolism

OBJECTIVETo Investigate the biological effects of miR-144 in rats' pulmanory injury induced by nanosized SiO₂preliminarily.

METHOD150 healthy SD rats were divided into five groups randomly: the control group, the nanosized SiO₂groups of 6.25, 12.5, 25.0 mg/ml, and the microsized SiO₂group of 25.0 mg/ml, 30 rats each group. Six rats were sacrificed for their pathological change on the 7th, 15th, 30th, 60th and 90th day after exposure. The expression levels of mature miR-144 in lung tissue of the rats after instilled intracheally nanosized SiO₂at 90d was detected by Quantitative Reverse Transcription PCR. Target prediction for miR-144 was conducted by databases of Target-scan, microRNA.org and miRDB. Function-significant enrichment analysis and signal pathway analysis for predicted target genes were respectively conducted by the Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes, then target genes related to pulmonary fibrosis were screened out.

RESULTSThe expression of miR-144 was up-regulated in lung tissue of rats exposed to nanosized SiO₂. The result was consistent with the results of high-throughput sequencing Hiseq 2000. The target genes of miR-144 related to fibrosis or signal pathway involved in fibrosis were screened out.They are SMAD4, SMAD5, ADAMTS3, ADAMTS15 and ADAMTS19.

CONCLUSIONMiR-144 probably participate in the regulation of fibrosis, which may play an important role in pulmonary injury induced by nanosized SiO₂.

Animals ; Lung ; pathology ; Lung Injury ; chemically induced ; metabolism ; pathology ; MicroRNAs ; metabolism ; Nanoparticles ; adverse effects ; Pulmonary Fibrosis ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Silicon Dioxide ; toxicity

OBJECTIVETo compare the effects of oral treatment with tetrandrine (TD) and N-acetylcys-teine (NAC) separately or jointly on silica-exposed rats.

METHODS40 sprague-Dawly (SD) rats were randomly divided into normal saline group, quartz group, TD treatment group (50 mg/kg), NAC treatment group (500 mg/kg) and combined treatment group (TD: 50 mg/kg + NAC: 500 mg/kg). Rats in normal saline group and other groups received intratracheal instillation of normal saline and quartz dust suspension respectively. Treatment groups were given TD, NAC separately or jointly via esophagus the next day after instillation, once a day and six times a week for 30 consecutive days. At the end of experiment, the pathological changes of lung tissues were evaluated by the methods of Foot, HE and Masson staining, the level of hydroxyproline (HYP), malondjalde-hyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lung tissues were measured by alkaline hydrolysis method, the barbituric acid method and enzyme-linked immunosorbent assay (ELISA) respectively.

RESULTSCompared with the quartz group, lymph nodes/body coefficients in all treatment groups and lung/body coefficient in combined treatment group were significantly decreased (P < 0.05). Pathology results showed that the normal saline group demonstrated no obvious evidence of lung damage. The quartz group lungs silicotic lesions focused on II~III level, the TD treatment group was mainly with I level, the NAC treatment group was mainly with I~II level, and the combined treatment group only showed little silicotic nodule, no obvious fibrosis. HYP content in TD treatment group and combined treatment group were significantly lower than that in the quartz group (P < 0.05), while it showed no obvious change in NAC treatment group. MDA content in lung tissues of each treatment group (TD treatment group, NAC treatment group and combined treatment group) were 18.80 ± 2.94, 20.13 ± 4.01 and 17.05 ± 3.52 nmol/ml respectively, which lower than in the quartz group (23.99 ± 3.26 nmol/ml). The level of IL-6 in lung tissues of the quartz group were 89.57 ± 8.78 pg/ml. After TD and NAC monotherapy, the IL-6 content decreased to 79.22 ± 9.65 pg/ml and 81.63 ± 5.72 pg/ml, and it decreased more significantly after combined medication (74.37 ± 3.17 pg/ml). The level of TNF-α in the quartz group were 59.05 ± 4.48 pg/ml. After TD and NAC monotherapy, the TNF-α content decreased to 50.48 ± 2.76 pg/ml and 54.28 ± 4.30 pg/ml, and it decreased more significantly after combined medication (49.10 ± 4.98 pg/ml).

CONCLUSIONNAC and TD could reduce MDA, TNF-α and IL-6 levels in lung tissue, and alleviate SiO2-induced pulmonary fibrosis in rats. Combined treatment with TD and NAC was more effective than TD or NAC treatment separately.

Acetylcysteine ; pharmacology ; Animals ; Benzylisoquinolines ; pharmacology ; Disease Models, Animal ; Dust ; Hydroxyproline ; metabolism ; Interleukin-6 ; metabolism ; Lung ; pathology ; Malondialdehyde ; metabolism ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; Quartz ; toxicity ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Silicosis ; drug therapy ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the pulmonary toxicity of different concentrations of nano-silica (nano-SiO2) under continuous dynamic inhalation conditions in the rat.

METHODS48 male Sprague-Dawley rats were randomly divided into four groups, including the dispersant control group (saline) and nano-SiO2 low-dose group (0.3%, w/v), the middle-dose group (1%) and the high-dose group (3%). Animals were sacrificed at 28 d after exposure under continuous dynamic inhalation conditions, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected. And following items were observed: body coefficient, BALF related items (leukocytes and classification, total protein content, LDH activity), lung tissue pathological changes (HE staining), and pulmonary fibrosis forming (collagen fiber VG staining).

RESULTSCompared to the dispersant control group, there was no significant change on lung organ coefficient in Nano-SiO2 group (P < 0.05). The BALF total WBC count in 1% and 3% in nano-SiO2 groups showed higher value than the dispersant control group (P < 0.05). No obvious changes were found on total protein content and LDH activity in nano-SiO2 groups compared to the dispersant control group (P > 0.05). For differential WBC counts, lymphocyte count in BALF in nano-SiO2 groups was significantly decreased (P < 0.05), monocyte and macrophage counts were significantly increased (P < 0.05), but there was no difference on the proportion of neutrophils (P > 0.05). HE staining results showed that the obvious thickening of alveolar wall in nano-SiO2 groups, inflammatory cell infiltration also increased around the bronchial and vascular wall. Lung fibrosis VG staining showed no significant change of collagen fiber distribution.

CONCLUSIONUnder our experimental conditions, the continuous dynamic inhalation of nano-SiO2 only caused the significant inflammation in rat lungs, pulmonary fibrosis phenomenon could not be observed significantly.

Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; Inhalation Exposure ; Lung ; drug effects ; metabolism ; pathology ; Male ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Silicon Dioxide ; administration & dosage ; toxicity

OBJECTIVEThis study was designed to evaluate the role of interleukin (IL)-1β in the development of fibrosis in mice exposed to silica.

METHODSThe total of 96 Male C57BL/6 mice were divided into four groups. (1) blank control group, (2) PBS group in which mice were instilled with PBS only, (3) silica + IL-1β mAb group in which mice were instilled with 2.5 mg silica dust and 40 µg anti-IL-1β mAb, (4) silica group in which mice were instilled with 2.5 mg silica dust and 40 µg IgG. The final volume of suspension or PBS instilled into the mouse was 50 µl. At 7, 28 and 84 days after treatment, 8 mice were sacrificed in each group. Then BALF was collected for the count of inflammatory cells and cytokines determination. The lung tissues were collected for the detecting of mRNA levels of fibrogenic molecules.

RESULTSThe collagen deposition induced by silica in the lung tissues was partly inhibited by anti-IL-1β. A intensely pulmonary cytokines such as IL-1β, TNF-α, MCP-1 were induced by crystalline silica exposure, and partly inhibited by anti-IL-1β. The levels of TGF-β and fibronectin in silica exposed mice were significantly elevated than those in control mice at days 28 and 84 after treatment (P < 0.01). And the mRNA levels of TGF-β, collagen I and fibronectin were significantly decreased in silica+IL-1β mAb group when compared with those in silica group at days 7, 28 and 84 (P < 0.01). There was a significant decrease of the ratios of IFN-γ/IL-4 in both silica+anti-IL-1β mAb and silica groups when compared with those in control mice at the above three time points (P < 0.01). However, the IFN-γ/IL-4 ratios in silica+anti-IL-1β group were significantly higher than those in silica group at 7, 28 and 84 days (P < 0.05 or P < 0.01).

CONCLUSIONIL-1β may promote the pulmonary fibrosis in mice exposed to silica.

Animals ; Antibodies, Monoclonal ; pharmacology ; Bronchoalveolar Lavage Fluid ; chemistry ; Collagen Type I ; metabolism ; Disease Models, Animal ; Fibronectins ; metabolism ; Interferon-gamma ; metabolism ; Interleukin-1beta ; metabolism ; physiology ; Interleukin-4 ; metabolism ; Lung ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Silicon Dioxide ; toxicity ; Transforming Growth Factor beta ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the effects of interleukin-17 (IL-17) on the proliferation, transformation and collagen synthesis of the lung fibroblasts in mice with bleomycin-induced pulmonary fibrosis.

METHODSIn a mouse model of pulmonary fibrosis established by intratracheal administration of 5 mg/kg bleomycin, the dynamic expressions of IL-17/IL-17 receptor (IL-17R) mRNAs were detected by RT-PCR. At 14 days following bleomycin administration, the pulmonary fibroblasts were isolated, cultured and identified. MTT assay was used to assess the proliferation of the pulmonary fibroblasts in response to IL-17 treatment at different concentrations, and RT-PCR and Western blotting were employed to examine the mRNA and protein expressions of α-smooth muscle actin (α-SMA) and types I and III collagen.

RESULTSIL-17/IL-17R mRNA levels were increased obviously in the pulmonary fibroblasts of rats with pulmonary fibrosis, and the highest expressions occurred at 14 days following bleomycin administration. Exogenous IL-17, at the optimal concentration of 50 ng/ml, significantly promoted the proliferation of the pulmonary fibroblasts in primary culture and obviously increased α-SMA expression and types I and III collagen synthesis in the fibroblasts.

CONCLUSIONIL-17 can promote the proliferation, transformation, and collagen synthesis of the pulmonary fibroblasts from rats with bleomycin-induced pulmonary fibrosis.

Animals ; Bleomycin ; Cell Proliferation ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Collagen Type III ; biosynthesis ; Epithelial-Mesenchymal Transition ; Fibroblasts ; metabolism ; pathology ; Interleukin-17 ; genetics ; metabolism ; Lung ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; RNA, Messenger ; genetics ; metabolism ; Receptors, Interleukin-17 ; genetics ; metabolism

OBJECTIVETo explore the role of hypoxia-inducible factor 1alpha (HIF-1α) in early lung fibrosis of rats with acute paraquat (PQ) poisoning.

METHODSForty eight healthy SD rats were randomly divided into control group (6 rats) and paraquat poisoning group (42 rats). Control group was exposed to 1 ml normal solution by gastric gavage. The paraquat group was exposed to 1 ml paraquat solution (50 mg/kg) by gastric gavage for 2, 6, 12, 48, 72 and 120 h, respectively. The arterial blood gas analysis (PaO(2)) was detected. The pathological examinations of lung tissues were performed by HE and Mason staining. HIF-1α in lung tissues were measured by immunofluorescence. Western blot assay was used to detect the expression levels of HIF-1α protein in lung tissues.

RESULTSPaO2 of rats exposed to paraquat for 72 h was (62.33 ± 0.22) mm Hg, which was significantly lower than that (96.00 ± 5.20) of control group (P < 0.05). Pathological examination by HE staining indicated that the acute diffuse lesion appeared in the alveolar capillary endothelium, epithelia and interstitial tissues, and there was the inflammatory cell infiltration in the alveolar of rats exposed to paraquat at 2 h after exposure. At 12 h after exposure, the interstitial edema in lung tissues of rats decreased and the alveolar space became narrow. At 120 h after exposure, there were the alveolar structure derangement, abundant cicatrix, more fibroblasts and peripheral inflammation absorption. Pathological examination by Masson staining showed that there was obvious collagen deposition in the alveolar epithelia at 2h after exposure, the increased collagen fibrosis at 24 and 48 h after exposure and the obvious damage of alveolar tissues or much more fibrous connective tissue deposition at 120 h after exposure. The results of western blot and immunofluorescence assays exhibited that the expression levels of HIF-1α in lung tissues at 2, 24 and 48 h after exposure significantly increased, as compared with control group (P < 0.05), but there were no significant differences of HIF-1α expression among sub-groups at different time points after exposure.

CONCLUSIONThe results of present study shown that there were the pulmonary fibrosis and increased expression of HIF-1α in acute PQ poisoning rats at the early stage, and HIF-1α may be associated with pulmonary fibrosis.

Acute Lung Injury ; chemically induced ; complications ; metabolism ; Animals ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Male ; Paraquat ; poisoning ; Pulmonary Fibrosis ; etiology ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley