Intratracheal Instillation Of Bleomycin Research Articles

Chemoreflex sensitization occurs in both male and female rats during recovery from acute lung injury

IntroductionSex-specific patterns in respiratory conditions, such as asthma, COPD, cystic fibrosis, obstructive sleep apnea, and idiopathic pulmonary fibrosis, have been previously documented. Animal models of acute lung injury (ALI) have offered insights into sex differences, with male mice exhibiting distinct lung edema and vascular leakage compared to female mice. Our lab has provided evidence that the chemoreflex is sensitized in male rats during the recovery from bleomycin-induced ALI, but whether sex-based chemoreflex changes occur post-ALI is not known. To bridge this gap, the current study employed the bleomycin-induced ALI animal model to investigate sex-based differences in chemoreflex activation during the recovery from ALI.MethodsALI was induced using a single intra-tracheal instillation of bleomycin (bleo, 2.5 mg/Kg) (day 1). Resting respiratory frequency (fR) was measured at 1-2 days pre-bleo, day 7 (D7) post-bleo, and 1 month (1 mth) post-bleo. The chemoreflex responses to hypoxia (10% O2, 0% CO2) and normoxic-hypercapnia (21% O2, 5% CO2) were measured before bleo administration (pre-bleo) and 1 mth post-bleo using whole-body plethysmography. The apnea-hypopnea Index (AHI), post-sigh apneas, and sighs were measured at each time point.ResultsThere were no significant differences in resting fR between male and female rats at the pre-bleo time point or in the increase in resting fR at D7 post-bleo. At 1 mth post-bleo, the resting fR was partially restored in both sexes but the recovery towards normal ranges of resting fR was significantly lower in male rats. The AHI, post-sigh apneas, and sighs were not different between male and female rats pre-bleo and 1 mth post-bleo. However, at D7 post-bleo, the male rats exhibited a higher AHI than female rats. Both male and female rats exhibited a sensitized chemoreflex in response to hypoxia and normoxic-hypercapnia with no significant differences between sexes.ConclusionA sex difference in resting ventilatory parameters occurs post ALI with a prolonged increase in resting fR and larger AHI in male rats. On the other hand, we did not find any sex differences in the chemoreflex sensitization that occurs at 1 mth post-bleo. This work contributes to a better understanding of sex-based variations in lung disorders.

The role of quercetin in ameliorating bleomycin-induced pulmonary fibrosis: insights into autophagy and the SIRT1/AMPK signaling pathway.

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology characterized by a constant incidence rate. Unfortunately, effective pharmacological treatments for this condition are lacking and the identification of novel therapeutic approaches and underlying pathological mechanisms are required. This study investigated the potential of quercetin in alleviating pulmonary fibrosis by promoting autophagy and activation of the SIRT1/AMPK pathway. Mouse models of IPF were divided into four treatment groups: control, bleomycin (BLM), quercetin (Q), and quercetin + EX-527 (Q + E) treatment. Pulmonary fibrosis was induced in the mouse models through intratracheal instillation of BLM. Various indexes were identified through histological staining, Western blotting analysis, enzyme-linked immunosorbent assay, immunohistochemistry, and transmission electron microscopy. Quercetin treatment ameliorated the pathology of BLM-induced pulmonary fibrosis of mice by reducing α-smooth muscle actin (α-SMA), collagen I (Col I), and collagen III (Col III) levels, and also improved the level of E-cadherin in lung tissue. Furthermore, Quercetin significantly enhanced LC3II/LC3I levels, decreased P62 expression, and increased the number of autophagosomes in lung tissue. These effects were accompanied by the activation of the SIRT1/AMPK pathway. Treatment with EX-527, an inhibitor for SIRT1, reversed all effects induced by quercetin. This study showed that quercetin could alleviate pulmonary fibrosis and improve epithelial-mesenchymal transition by acting on the SIRT1/AMPK signaling pathway, which may be achieved by regulating the level of autophagy.

P311 KO Mice are Protected from Experimentally Induced Lung Fibrosis

Pulmonary fibrosis (PF) is a fatal chronic interstitial lung disease and one of the most irreversible forms of tissue/organ fibrosis. Idiopathic pulmonary fibrosis is a very progressive disease accompanied by inflammatory damage with a median survival of less than 5 years. Etiology of IPF is still elusive with potential reasons being genetic predisposition and environmental exposures including particulates, radiation, and SARS-CoV-2. Recent studies indicate that about 50% of COVID19 associated acute respiratory distress syndrome survivors develop PF. There are very limited treatment options with no curative therapies available for PF apart from invasive lung transplantation. P311 is an 8 kDa protein previously shown to have a key role in lung regeneration. As P311 overexpression in fibroblasts induced myofibroblast phenotype, we hypothesized that P311 has a role in tissue fibrosis. We induced PF by intra-tracheally instilling bleomycin (BL) in P311 knockout (KO) mice and wild type (WT, C57BL/6) control mice and collected lungs after 2-5 weeks. P311 KO mice showed significantly less fibrosis. After intra-tracheal instillation of BL, the lungs of P311 KO mice (D21) had significantly reduced number of myofibroblasts as indicated by reduced SM α-actin expression and collagen deposition as indicated by Masson trichrome staining compared to their WT counterparts. We further observed reduced levels of TGF-β1-3 and Smad-2 and -3 along with decreased epithelial to mesenchymal transdifferentiation markers in the lungs of bleomycin treated P311 KOs compared to WT controls. Further bronchoalveolar lavage fluid (BALF) was collected (D14) and utilized to determine the pulmonary inflammation by determining the total and different immune cell populations in the BALF and lung samples by FACS analysis. Even though we saw a significant increase in the BALF cellularity, we did not observe significant changes in T-cell, macrophage, and neutrophil numbers between WT and P311KOs. However, lung cell isolates showed significantly increased CD3 and CD4 positive cells indicating increased T-cells and helper T-cells in fibrotic P311KO lungs compared to WT lungs. In conclusion, bleomycin administration resulted in lung fibrosis in WT mice, but P311 KO mice are protected. This study was partially supported by research funding to KB, from American Lung Association, DA-196629-N. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sex differences in Acute Lung Injury (ALI)-Induced Respiratory Functional Changes in a Bleomycin Rat Model

Introduction: Acute lung injury (ALI) is a pathology characterized primarily by profound disruption of the epithelial-endothelial interface, leukocyte migration into the alveolar space, leading to disordered gas exchange and consequential respiratory failure. There exist several animal models to study the pathophysiology of ALI. Bleomycin, a cancer therapeutic, has been shown to consistently induce the ALI phenotype in rodent models. We have previously shown that intra-tracheal bleomycin instillation in rats produces deleterious changes in respiratory function in both acute and recovery phases of ALI. In this study, we sought to elucidate the effect of sex bleomycin-induced ALI. Methods: To do this, cohorts of male and female Sprague-Dawley rats were measured using whole-body plethysmography (WBP) where the following respiratory parameters were recorded prior to bleomycin exposure (Week 0): Volume of Oxygen consumed normalized to body weight (VO2/kg), Respiratory rate (RR), Tidal Volume normalized to body weight (TV/kg), Minute Ventilation normalized to body weight (MV/kg), enhanced pause (Penh), pause (PAU), ratio rate of achieving peak expiatory flow (Rpef), peak inspiratory flow (box) (PIFb), peak expiratory flow box (PEFb), inspiratory time (Ti), expiratory time (Te), expiratory flow at the point of 50%TV (EF50), end-inspiratory pause (EIP), end-expiratory pause (EEP), relaxation time (Tr) and time of brake (TB). A single dose of intra-tracheal bleomycin (2.5mg/kg) was instilled and subsequent WBP recordings were performed weekly during the acute phase of ALI (Week 1), and the recovery phase of ALI (Week 4). Results: Our results show that bleomycin-induced ALI resulted in greater DTE (Weeks 1-3) and DTR (Weeks 1-2) in females compared to males. Measures of airway obstruction were also shown to be sex-dependent, as DRpef (Week 1), DPAU (Weeks 2-4), and DPenh (Weeks 2-4) were significantly different between males and females. EF50, a metric highly correlated with lung pathologies, remained unchanged between sexes post-ALI. While inducing ALI did not alter DPIFb between the sexes, DPEFb was elevated among males compared to females (Weeks 2,4). DEIP and DEEP both showed sex-dependent changes post-ALI, with females displaying a greater decrease compared to males. Additionally, there was a greater decrease in DTV/kg among females compared to males post-ALI (Weeks 1-3). DRR, DMV/kg, and DVO2/kg were unchanged across the 4 weeks post-ALI between sexes. Conclusion: Our study reveals sex-specific nuances in bleomycin-induced acute lung injury (ALI) in Sprague-Dawley rats. Differential responses in airway obstruction measures and distinct impacts on respiratory dynamics underscore the importance of considering sex in researching ALI. This work is supported by NIH R01HL152160-01. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Sex-based Differences in Chemoreflex during Recovery from Acute Lung Injury

Introduction- Sex-specific patterns in respiratory conditions, such as asthma, COPD, cystic fibrosis, obstructive sleep apnea, and idiopathic pulmonary fibrosis, have been previously documented. Animal models of acute lung injury (ALI) have offered insights into sex differences, with male mice exhibiting distinct lung edema and vascular leakage compared to female mice. Our lab has provided evidence that the peripheral (or carotid body) chemoreflex is sensitized in male rats during the recovery from bleomycin-induced ALI, but whether sex-based chemoreflex changes occur post-ALI in not known. To bridge this gap, our current study employed the bleomycin-induced ALI animal model to investigate sex-based differences in chemoreflex activation during the recovery of ALI. Methods- ALI was induced using a single intra-tracheal instillation of bleomycin (bleo) (day 1). Resting fR (respiratory frequency) was measured at pre-bleo, day 7 (D7) post-bleo, and 1 month (1 mth) post-bleo time points. The chemoreflex response to hypoxia (10% O2, 0% CO2) and normoxic-hypercapnia (21% O2, 5% CO2) were measured before bleo administration (pre-bleo) time point and 1 month (1 mth) post-bleo using whole-body plethysmography. Apnea-hypopnea Index (AHI), post-sigh apneas, and sighs were measured at each time point. Results- Resting fR: There were no significant differences in resting fR, either at pre-bleo time point or at day 7 (D7) post-bleo between male and female rats. At 1 mth post-bleo, the resting fR was partially restored in both sexes but the recovery towards normal ranges of resting fR was significantly slower in male rats compared to female rats. AHI, post-sigh apneas, and sighs: At the pre-bleo and 1 mth post-bleo time points, there were no significant differences in AHI, post-sigh apneas, and sighs between male and female rats. However, at D7 post-bleo, the male rats exhibited a higher AHI than female rats; Chemoreflex sensitivity: Both male and female rats exhibited a sensitized chemoreflex activation to hypoxia and normoxic-hypercapnia with no significant differences between sexes. Discussion- Our study showed a sex difference in resting ventilatory parameters including resting fR and AHI post ALI. On the other hand, we did not find any sex difference in chemoreflex sensitization at 1 mth post-bleo. This research contributes to a better understanding of sex-based variations in lung disorders. This study was supported by NIH grant R01 HL-152160 and in part, by NIH grants R01 HL-121012 and R01 HL126796. H-JW was also supported by Margaret R. Larson Professorship in Anesthesiology. IZ was partially supported by the Theodore F. Hubbard Foundation. KK was supported by the AHA predoctoral fellowship -AHA award #903872 by the American Heart Association. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Shenqi Chongcao Formula ameliorates inflammatory response in rats with pulmonary fibrosis by activating the ASS1/src/STAT3 signaling pathway

To observe the effect of Shenqi Chongcao (SQCC) Formula on the ASS1/src/STAT3 signaling pathway in a rat model of lung fibrosis and explore its therapeutic mechanism. A total of 120 male SD rats were divided equally into 5 groups, including a blank control group with saline treatment and 4 groups of rat models of idiopathic pulmonary fibrosis induced by intratracheal instillation of bleomycin. One day after modeling, the rat models were treated with daily gavage of 10 mL/kg saline, SQCC decoction (0.423 g/kg), pirfenidone (10 mL/kg), or intraperitoneal injection of arginine deiminase (ADI; 2.25 mg/kg, every 3 days) for 28 days. After the treatments, the lung tissues of the rats were collected for calculating the lung/body weight ratio, observing histopathology using HE and Masson staining, and analyzing the inflammatory cells in BALF using Giemsa staining. Serum chemokine ligand 2 (CCL2) and transforming growth factor-β1 (TGF-β1) levels were measured with ELISA. The protein expressions of src, p-srcTry529, STAT3, and p-STAT3Try705 and the mRNA expressions of ASS1, src and STAT3 in the lung tissues were detected using Western blotting and RT-qPCR. The neutrophil, macrophage and lymphocyte counts and serum levels of CCL2 and TGF-β1 were significantly lower in SQCC, pirfenidone and ADI treatment groups than in the model group at each time point of measurement (P < 0.05). P-srcTry529 and p-STAT3Try705 protein expression levels and ASS1, src, and STAT3 mRNA in the lung tissues were also significantly lower in the 3 treatment groups than in the model group (P < 0.05). SQCC Formula can alleviate lung fibrosis in rats possibly by activating the ASS1/src/STAT3 signaling pathway in the lung tissues.

Maximizing the Therapeutic Effect of Endothelin Receptor Antagonists in Pulmonary Fibrosis: A Paradigm for Treating the Disease.

Using a lipopolysaccharide model of acute lung injury, we previously showed that endothelin-1 (ET-1), a potent mediator of vasoconstriction, may act as a "gatekeeper" for the influx of inflammatory cells into the lung. These studies provided a rationale for testing the effect of HJP272, an endothelin receptor antagonist (ERA), in hamster models of pulmonary fibrosis induced by intratracheal instillation of either bleomycin (BLM) or amiodarone (AM). To determine the temporal effects of blocking ET-1 activity, animals were given HJP272 either 1 h before initiation of lung injury or 24 h afterward. The results indicated that pretreatment with this agent caused significant reductions in various inflammatory parameters, whereas post-treatment was ineffective. This finding suggests that ERAs are only effective at a very early stage of pulmonary fibrosis and explains their lack of success in clinical trials involving patients with this disease. Nevertheless, ERAs could serve as prophylactic agents when combined with drugs that may induce pulmonary fibrosis. Furthermore, developing a biomarker for the initial changes in the lung extracellular matrix could increase the efficacy of ERAs and other therapeutic agents in preventing the progression of the disease. While no such biomarker currently exists, we propose the ratio of free to peptide-bound desmosine, a unique crosslink of elastin, as a potential candidate for detecting the earliest modifications in lung microarchitecture associated with pulmonary fibrosis.

Assessment of progression of pulmonary fibrosis based on metabonomics and analysis of intestinal microbiota

The main purpose of this study was to explore the changes of biomarkers in different developmental stages of bleomycin-induced pulmonary fibrosis (PF) in rats via comprehensive pathophysiology, UPLC-QTOF/MS metabonomic technology, and 16S rRNA gene sequencing of intestinal microbiota. The rats were randomly divided into normal control and 1-, 2- and 4-week model group. The rat model of PF was established by one-time intratracheal instillation of bleomycin. The levels of inflammatory and fibrosis-related factors such as hydroxyproline (HYP), type III procollagen (COL-III), type IV collagen (COL-IV), hyaluronidase (HA), laminin (LN), interleukin (IL)-1β, IL-6, malondialdehyde (MDA) increased and superoxide dismutase (SOD) decreased as the PF cycle progressed. In the 1-, 2- and 4-week model group, 2, 19 and 18 potential metabolic biomarkers and 3, 16 and 12 potential microbial biomarkers were detected, respectively, which were significantly correlated. Glycerophospholipid metabolism pathway was observed to be an important pathway affecting PF at 1, 2 and 4 weeks; arginine and proline metabolism pathways significantly affected PF at 2 weeks. Linoleic acid metabolism pathway exhibited clear metabolic abnormalities at 2 and 4 weeks of PF, and alpha-linolenic acid metabolism pathway significantly affected PF at 4 weeks.

Unraveling the mechanism of ethyl acetate extract from Prismatomeris connata Y. Z. Ruan root in treating pulmonary fibrosis: insights from bioinformatics, network pharmacology, and experimental validation.

Pulmonary fibrosis is a terminal lung disease characterized by fibroblast proliferation, extracellular matrix accumulation, inflammatory damage, and tissue structure destruction. The pathogenesis of this disease, particularly idiopathic pulmonary fibrosis (IPF), remains unknown. Macrophages play major roles in organ fibrosis diseases, including pulmonary fibrosis. The phenotype and polarization of macrophages are closely associated with pulmonary fibrosis. A new direction in research on anti-pulmonary fibrosis is focused on developing drugs that maintain the stability of the pulmonary microenvironment. We obtained gene sequencing data and clinical information for patients with IPF from the GEO datasets GSE110147, GSE15197, GSE24988, GSE31934, GSE32537, GSE35145, GSE53845, GSE49072, GSE70864, and GSE90010. We performed GO, KEGG enrichment analysis and GSEA analysis, and conducted weighted gene co-expression network analysis. In addition, we performed proteomic analysis of mouse lung tissue. To verify the results of bioinformatics analysis and proteomic analysis, mice were induced by intratracheal instillation of bleomycin (BLM), and gavaged for 14 days after modeling. Respiratory function of mice in different groups was measured. Lungtissues were retained for histopathological examination, Western Blot and real-time quantitative PCR, etc. In addition, lipopolysaccharide, interferon-γ and interleukin-4 were used to induce RAW264.7 cells for 12h in vitro to establish macrophage inflammation and polarization model. At the same time, HG2 intervention was given. The phenotype transformation and cytokine secretion of macrophages were investigated by Western Blot, RT-qPCR and flow cytometry, etc. Through bioinformatics analysis and experiments involving bleomycin-induced pulmonary fibrosis in mice, we confirmed the importance of macrophage polarization in IPF. The analysis revealed that macrophage polarization in IPF involves a change in the phenotypic spectrum. Furthermore, experiments demonstrated high expression of M2-type macrophage-associated biomarkers and inducible nitric oxide synthase, thus indicating an imbalance in M1/M2 polarization of pulmonary macrophages in mice with pulmonary fibrosis. Our investigation revealed that the ethyl acetate extract (HG2) obtained from the roots of Prismatomeris connata Y. Z. Ruan exhibits therapeutic efficacy against bleomycin-induced pulmonary fibrosis. HG2 modulates macrophage polarization, alterations in the TGF-β/Smad pathway, and downstream protein expression in the context of pulmonary fibrosis. On the basis of our findings, we believe that HG2 has potential as a novel traditional Chinese medicine component for treating pulmonary fibrosis.

Adenophorae Radix Reduces Fibrosis in a Bleomycin-Induced Pulmonary Fibrosis Mouse Model

Background: A screening study investigated the effects of lung-moistening herbal medicines on a bleomycin-induced pulmonary fibrosis mouse model and reported that the efficacy of Adenophorae Radix (ADR) was higher than that of other remedies. Objectives: This study aimed to investigate the antifibrotic efficacy and mechanism of action of ADR in a mouse model of bleomycin-induced pulmonary fibrosis. Materials and Methods: ADR water extract was prepared and orally administered at doses of 30, 100, and 300 mg/kg for 10 days after intratracheal bleomycin instillation. Changes in the body weight and lung histology were assessed. In addition, the quantity of inflammatory cells in the bronchoalveolar lavage fluid (BALF) and the level of transforming growth factor-β and α-smooth muscle actin (α-SMA) were measured. Results: ADR treatment decreased the degree of histological fibrosis based on the Ashcroft score and the number of inflammatory cells in BALF. Moreover, α-SMA level in the lung tissue decreased. ADR at 300 mg/kg resulted in the most significant reduction in the measured indicators. Conclusion: The results indicate that the administration of 300 mg/kg ADR attenuates pulmonary fibrosis in an animal model of idiopathic pulmonary fibrosis; thus, ADR can be considered as a candidate treatment for lung fibrosis.

Utilizing MRI, [18F]FDG-PET and [89Zr]Zr-DFO-28H1 FAP-PET tracer to assess inflammation and fibrogenesis in a reproducible lung injury rat model: a multimodal imaging study

ObjectiveAccurate imaging biomarkers that indicate disease progression at an early stage are highly important to enable timely mitigation of symptoms in progressive lung disease. In this context, reproducible experimental models and readouts are key. Here, we aim to show reproducibility of a lung injury rat model, by inducing disease and assessing disease progression by multi-modal non-invasive imaging techniques at two different research sites. Furthermore, we evaluated the potential of fibroblast activating protein (FAP) as an imaging biomarker in the early stage of lung fibrosis.MethodsAn initial lung injury rat model was set up at one research site (Lund University, Lund, Sweden) and repeated at a second site (Radboudumc, Nijmegen, The Netherlands). To induce lung injury, Sprague-Dawley rats received intratracheal instillation of bleomycin as one single dose (1,000 iU in 200 µL) or saline as control. Thereafter, longitudinal images were acquired to track inflammation in the lungs, at 1 and 2 weeks after the bleomycin challenge by magnetic resonance imaging (MRI) and [18F]FDG-PET. After the final [18F]FDG-PET scan, rats received an intravenous tracer [89Zr]Zr-DFO-28H1 (anti-FAP antibody) and were imaged at day 15, to track fibrogenesis. Upon termination, bronchoalveolar lavage (BAL) was performed to assess cell and protein concentration. Subsequently, the biodistribution of [89Zr]Zr-DFO-28H1 was measured ex vivo and the spatial distribution in lung tissue was studied by autoradiography. Lung sections were stained, and fibrosis assessed using the modified Ashcroft score.ResultsBleomycin-challenged rats showed body weight loss and increased numbers of immune cells and protein concentrations after BAL compared with control animals. The initiation and progression of the disease were reproduced at both research sites. Lung lesions in bleomycin-exposed rats were visualized by MRI and confirmed by histology. [18F]FDG uptake was higher in the lungs of bleomycin-challenged rats compared with the controls, similar to that observed in the Lund study. [89Zr]Zr-DFO-28H1 tracer uptake in the lung was increased in bleomycin-challenged rats compared with control rats (p = 0.03).ConclusionHere, we demonstrate a reproducible lung injury model and monitored disease progression using conventional imaging biomarkers MRI and [18F]FDG-PET. Furthermore, we showed the first proof-of-concept of FAP imaging. This reproducible and robust animal model and imaging experimental set-up allows for future research on new therapeutics or biomarkers in lung disease.

Protective effect and mechanism of Maiwei Yangfei Decoction on pulmonary fibrosis mice based on Nrf2 regulation of oxidative stress

This study explored the effect and mechanism of Maiwei Yangfei Decoction(MWYF) on pulmonary fibrosis(PF) mice. MWYF was prepared, and its main components were detected by ultra-high-performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-MS/MS). Male C57BL/6J mice were randomly divided into a control group, a model group, a pirfenidone(PFD) group, and low-, medium-, and high-dose MWYF groups, with 10 mice in each group. The PF model was induced in mice except for those in the control group by intratracheal instillation of bleomycin(BLM), and model mice were treated with saline or MWYF or PFD by gavage the next day. The water consumption, food intake, hair, and activity of mice were observed daily. The pathological changes in lung tissues were observed by hematoxylin-eosin(HE) staining, Masson staining, and CT scanning. The level of hydroxyproline(HYP) in lung tissues was detected by alkaline hydrolysis. Immunohistochemistry was used to observe the expression of collagen type Ⅲ(COL3) and fibronectin. The mRNA expression levels of α-smooth muscle actin(α-SMA), type Ⅰ collagen α1(COL1α1), COL3, and vimentin were detected by reverse transcription real-time fluorescence quantitative polymerase chain reaction(RT-qPCR). Superoxide dismutase(SOD) and malondialdehyde(MDA) kits were used to detect oxidative stress indicators in lung tissues and serum. The nuclear translocation of nuclear factor E2-related factor 2(Nrf2) protein was detected by immunofluorescence. The protein and mRNA expression levels of Nrf2, catalase(CAT), and heme oxygenase 1(HO-1) in lung tissues were detected by Western blot and RT-qPCR. Twelve chemical components were detected by UPLC-MS/MS. Animal experiments showed that MWYF could improve alveolar inflammation, collagen deposition, and fibrosis in PF mice, increase body weight of mice, and down-regulate the expression of fibrosis indexes such as HYP, α-SMA, COL1α1, COL3, fibronectin, and vimentin in lung tissues. In addition, MWYF could potentiate the activity of SOD in lung tissues and serum of PF mice, up-regulate the expression level of Nrf2, and promote its transfer to the nucleus, up-regulate the levels of downstream antioxidant target genes CAT and HO-1, and then reduce the accumulation of lipid metabolite MDA. In summary, MWYF can significantly improve the pathological damage and fibrosis of lung tissues in PF mice, and its mechanism may be related to the activation of the Nrf2 pathway to regulate oxidative stress.

Induced pluripotent stem cells modulate the Wnt pathway in the bleomycin-induced model of idiopathic pulmonary fibrosis

BackgroundThe Wnt signaling pathway has been implicated in the pathogenesis of fibrotic disorders and malignancies. Hence, we aimed to assess the potential of the induced pluripotent stem cells (IPS) in modulating the expression of the cardinal genes of the Wnt pathway in a mouse model of idiopathic pulmonary fibrosis (IPF).MethodsC57Bl/6 mice were randomly divided into three groups of Control, Bleomycin (BLM), and BLM + IPS; the BLM mice received intratracheal instillation of bleomycin, BLM + IPS mice received tail vein injection of IPS cells 48 h post instillation of the BLM; The Control group received Phosphate-buffered saline instead. After 3 weeks, the mice were sacrificed and Histologic assessments including hydroxy proline assay, Hematoxylin and Eosin, and Masson-trichrome staining were performed. The expression of the genes for Wnt, β-Catenin, Lef, Dkk1, and Bmp4 was assessed utilizing specific primers and SYBR green master mix.ResultsHistologic assessments revealed that the fibrotic lesions and inflammation were significantly alleviated in the BLM + IPS group. Besides, the gene expression analyses demonstrated the upregulation of Wnt, β-Catenin, and LEF along with the significant downregulation of the Bmp4 and DKK1 in response to bleomycin treatment; subsequently, it was found that the treatment of the IPF mice with IPS cells results in the downregulation of the Wnt, β-Catenin, and Lef, as well as upregulation of the Dkk1, but not the Bmp4 gene (P values < 0.05).ConclusionThe current study highlights the therapeutic potential of the IPS cells on the IPF mouse model in terms of regulating the aberrant expression of the factors contributing to the Wnt signaling pathway.

Imrecoxib attenuates bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) is an incurable chronic progressive disease with a low survival rate and ineffective therapeutic options. We examined the effects of imrecoxib, a nonsteroidal anti-inflammatory drug, on experimental pulmonary fibrosis. The mouse IPF model was established by intratracheal instillation of bleomycin. From Day 0 to Day 13, the mice were orally administered imrecoxib (100 mg/kg) and pirfenidone (200 mg/kg) daily, and from Day 7 to Day 13, the mice were orally administered pirfenidone and imrecoxib daily. The tissues were dissected on the 14th day. Mouse body weight was measured, and histopathological examination and hydroxyproline content analysis confirmed that the administration of imrecoxib exerted a similar effect to pirfenidone. Compared with bleomycin-induced mice, imrecoxib-treated mice showed significantly reduced inflammatory factor expression (IL-1 and TNF-α) and inflammatory cell numbers (macrophages, lymphocytes, and neutrophils) in BALF (bronchoalveolar lavage fluid). Our experiment tested the ability of imrecoxib to inhibit the signal pathway involved in gene expression induced by TGF-β1 in the NIH-3T3 cell line in vitro. Western blotting showed that imrecoxib (20 μM and 40 μM) inhibited the expression of fibronectin, type I collagen and CTGF. In addition, imrecoxib reduced the levels of p-ERK1/2. The changes in the expression of related proteins in mouse lung tissue were similar to those in cells. In summary, our findings suggested that the administration of imrecoxib prevented and treated murine IPF by inhibiting inflammation and the TGF-β1-ERK1/2 signaling pathway.

Longitudinal x-ray based lung function measurement for monitoring Nintedanib treatment response in a mouse model of lung fibrosis

Lung fibrosis (LF) is a chronic progressive, incurable, and debilitating condition of the lung, which is associated with different lung disease. Treatment options are still sparse. Nintedanib, an oral tyrosine kinase inhibitor, significantly slows the LF progression. However, there is a strong need of further research and the development of novel therapies. In this study, we used a correlative set-up that combines X-ray based lung function (XLF) with microCT and whole body plethysmography (WBP) for a comprehensive functional and structural evaluation of lung fibrosis (LF) as well as for monitoring response to orally administered Nintedanib in the mouse model of bleomycin induced LF. The decline in lung function as early as one week after intratracheal bleomycin instillation was reliably detected by XLF, revealing the lowest decay rate in the LF mice compared to healthy ones. Simultaneously performed microCT and WBP measurements corroborated XLF findings by exhibiting reduced lung volume V^{insp}_{mu CT} and tidal volume TV_{WBP}. In LF mice XLF also revealed profound improvement in lung function one week after Nintedanib treatment. This positive response to Nintedanib therapy was further substantiated by microCT and WBP measurements which also showed significantly improved V^{insp}_{mu CT} and TV_{WBP} in the Nintedanib treated mice. By comparing the XLF data to structural features assessing the extent of fibrosis obtained by ex-vivo high-resolution synchrotron radiation-based imaging and classical histology we demonstrate that: (1) a simple low dose x-ray measurement like XLF is sensitive enough to pick up treatment response, (2) Nintedanib treatment successfully improved lung function in a bleomycin induced LF mouse model and (3) differences between the fully restored lung function and the partially reduced fibrotic burden compared to healthy and untreated mice. The presented analysis pipeline underlines the importance of a combined functional and anatomical readout to reliably measure treatment response and could easily be adapted to other preclinical lung disease models.

Aqueous extract of Epimedium sagittatum mitigates pulmonary fibrosis in mice

This study aims to investigate the intervention effect of the aqueous extract of Epimedium sagittatum Maxim on the mouse model of bleomycin(BLM)-induced pulmonary fibrosis, so as to provide data support for the clinical treatment of pulmonary fibrosis. Ninety male C57BL/6N mice were randomized into normal(n=10), model(BLM, n=20), pirfenidone(PFD, 270 mg·kg~(-1), n=15), and low-, medium-, and high-dose E. sagittatum extract(1.67 g·kg~(-1), n=15; 3.33 g·kg~(-1), n=15; 6.67 g·kg~(-1), n=15) groups. The model of pulmonary fibrosis was established by intratracheal instillation of BLM(5 mg·kg~(-1)) in the other five groups except the normal group, which was treated with an equal amount of normal saline. On the day following the modeling, each group was treated with the corresponding drug by gavage for 21 days. During this period, the survival rate of the mice was counted. After gavage, the lung index was calculated, and the morphology and collagen deposition of the lung tissue were observed by hematoxylin-eosin(HE) and Masson staining, respectively. The levels of reactive oxygen species(ROS) in lung cell suspensions were measured by flow cytometry. The levels of glutathione peroxidase(GSH-Px), total superoxide dismutase(T-SOD), and malondialdehyde(MDA) the in lung tissue were measured. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling(TUNEL) was employed to examine the apoptosis of lung tissue cells. The content of interleukin-6(IL-6), chemokine C-C motif ligand 2(CCL-2), matrix metalloproteinase-8(MMP-8), transforming growth factor-beta 1(TGF-β1), alpha-smooth muscle actin(α-SMA), E-cadherin, collagen Ⅰ, and fibronectin in the lung tissue was measured by enzyme-linked immunosorbent assay(ELISA). The expression levels of F4/80, Ly-6G, TGF-β1, and collagen Ⅰ in the lung tissue were determined by immunohistochemistry. The mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue were determined by qRT-PCR. The content of hydroxyproline(HYP) in the lung tissue was determined by alkaline hydrolysation. The expression of α-SMA and E-cadherin was detected by immunofluorescence, and the protein levels of α-SMA, vimentin, E-cadherin in the lung tissue were determined by Western blot. The results showed the aqueous extract of E. sagittatum increased the survival rate, decreased the lung index, alleviated the pathological injury, collagen deposition, and oxidative stress in the lung tissue, and reduced the apoptotic cells. Furthermore, the aqueous extract of E. sagittatum down-regulated the protein levels of F4/80 and Ly-6G and the mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue, reduced the content of IL-6, CCL-2, and MMP-8 in the alveolar lavage fluid. In addition, it lowered the levels of HYP, TGF-β1, α-SMA, collagen Ⅰ, fibronectin, and vimentin, and elevated the levels of E-cadherin in the lung tissue. The aqueous extract of E. sagittatum can inhibit collagen deposition, alleviate oxidative stress, and reduce inflammatory response by regulating the expression of the molecules associated with epithelial-mesenchymal transition, thus alleviating the symptoms of bleomycin-induced pulmonary fibrosis in mice.

Anthelmintic nitazoxanide protects against experimental pulmonary fibrosis.

Nitazoxanide is a therapeutic anthelmintic drug. Our previous studies found that nitazoxanide and its metabolite tizoxanide activated adenosine 5'-monophosphate-activated protein kinase (AMPK) and inhibited signal transducer and activator of transcription 3 (STAT3) signals. As AMPK activation and/or STAT3 inhibition are targets for treating pulmonary fibrosis, we hypothesized that nitazoxanide would be effective in experimental pulmonary fibrosis. The mitochondrial oxygen consumption rate of cells was measured by using the high-resolution respirometry system Oxygraph-2K. The mitochondrial membrane potential of cells was evaluated by tetramethyl rhodamine methyl ester (TMRM) staining. The target protein levels were measured by using western blotting. The mice pulmonary fibrosis model was established through intratracheal instillation of bleomycin. The examination of the lung tissues changes were carried out using haematoxylin and eosin (H&E), and Masson staining. Nitazoxanide and tizoxanide activated AMPK and inhibited STAT3 signalling in human lung fibroblast cells (MRC-5 cells). Nitazoxanide and tizoxanide inhibited transforming growth factor-β1 (TGF-β1)-induced proliferation and migration of MRC-5 cells, collagen-I and α-smooth muscle cell actin (α-SMA) expression, and collagen-I secretion from MRC-5 cells. Nitazoxanide and tizoxanide inhibited epithelial-mesenchymal transition (EMT) and inhibited TGF-β1-induced Smad2/3 activation in mouse lung epithelial cells (MLE-12 cells). Oral administration of nitazoxanide reduced the bleomycin-induced mice pulmonary fibrosis and, in the established bleomycin-induced mice, pulmonary fibrosis. Delayed nitazoxanide treatment attenuated the fibrosis progression. Nitazoxanide improves the bleomycin-induced pulmonary fibrosis in mice, suggesting a potential application of nitazoxanide for pulmonary fibrosis treatment in the clinic.

Effect of Gualou Xiebai Decoction on pulmonary fibrosis in rats based on pyroptosis pathway

This study investigated the effect of Gualou Xiebai Decoction on rats with bleomycin-induced pulmonary fibrosis. The rats were randomly divided into a control group, a model group, a low-dose Gualou Xiebai Decoction group(2.4 g·kg~(-1)), a high-dose Gualou Xiebai Decoction group(4.8 g·kg~(-1)), and pirfenidone group(150 mg·kg~(-1)). The model of pulmonary fibrosis was established by intratracheal instillation of bleomycin in all groups, except the control group. Since the second day of modeling, the corresponding drugs were given to rats by intragastric administration, once a day for 14 d and 28 d. The hematoxylin-eosin(HE) staining was used to evaluate the degree of inflammatory injury in lung tissues. The immunofluorescence staining was used to detect the expression of CD68 and CD163 in lung tissues of rats. The levels of tumor necrosis factor-α(TNF-α) and interleukin-10(IL-10) in serum and brochoalveolar lavage fluid(BALF) were detected by enzyme-linked immunosorbent assay(ELISA). The expression of pyroptosis-related genes in lung tissues of rats was detected by qRT-PCR. The results of HE staining and immunofluorescence staining showed that the lung tissue structure was normal in the control group. In addition, there were alveolar collapse or even closure in lung tissues of rats in the model group, with obvious inflammatory cell infiltration, and the expression of CD68 and CD163 was significantly up-regulated. As compared with the model group, the lung tissue structure of rats in the Gualou Xiebai Decoction groups was significantly improved, with alleviated inflammation, and the expression of CD68 and CD163 was decreased. As compared with the control group, the level of TNF-α in serum and BALF of rats in the model group was significantly increased(P&lt;0.01), the mRNA expression levels of alpha smooth muscle actin(α-SMA), collagen type Ⅰ alpha 1 chain(Col1a1), caspase-1, IL-1β, IL-18, gasdermin D(Gsdmd), and NOD-like receptor thermal protein domain associated protein 3(NLRP3) in lung tissues were significantly increased(P&lt;0.05, P&lt;0.01), and the mRNA expression level of E-cadherin was significantly decreased(P&lt;0.01). As compared with the model group, the level of TNF-α in serum and BALF was significantly down-regulated in the high-dose Gualou Xiebai Decoction group(P&lt;0.05, P&lt;0.01), and that of IL-10 was up-regulated(P&lt;0.05, P&lt;0.01). The mRNA expression levels of α-SMA, Col1a1, caspase-1, IL-18, Gsdmd, NLRP3 and IL-1β in lung tissues were significantly decreased(P&lt;0.05, P&lt;0.01) in the high-dose Gualou Xiebai Decoction group, and the mRNA expression level of E-cadherin was significantly increased(P&lt;0.05, P&lt;0.01). In conclusion, Gualou Xiebai Decoction can down-regulate the levels of inflammatory factors and related genes and effectively mitigate pulmonary fibrosis by regulating the pyroptosis pathways.

Icariside Ⅱ attenuates bleomycin-induced pulmonary fibrosis by modulating macrophage polarization

Ethnopharmacological relevanceNumerous studies have provided evidence supporting the significant roles of icariin, in the prevention of multiple chronic diseases like diabetes, liver fibrosis, cardiac fibrosis, renal fibrosis, and pulmonary fibrosis. In particular, Icariside II (ISE II), a prominent flavonoid glycoside derived from Epimedium brevicornum Maxim, the principal metabolite of icariin, has demonstrated noteworthy anti-inflammatory and anti-oxidant properties, along with its ability to protect against lung remodeling. However, the research exploring ISE Ⅱ's application in treating pulmonary fibrosis remains limited. Aim of the studyThe aim of this study was to assess the therapeutic efficacy of ISE II in models of pulmonary fibrosis, while also investigating its potential mechanisms of action in cell signaling pathways. Materials and methodsAn in vitro model of pulmonary fibrosis was established by treating NIH-3T3 cells with transforming growth factor-β1 (TGF-β1). Western blot, RT-qPCR, and scratch test were performed to assess the effect of ISE Ⅱ. In addition, a murine model of pulmonary fibrosis was induced by intratracheal instillation of bleomycin, and the therapeutic effect of ISE Ⅱ was tested by orally administering ISE Ⅱ at a dose of 10 mg/kg. Three weeks later, lung function, micro-CT, hydroxyproline content, pathological staining, and cytokines detection of BALF or serum were used to assess the anti-fibrosis effects of ISE Ⅱ. Next, immunofluorescence staining, flow cytometry, and in vivo transcriptomics were used to investigate the underlying mechanisms of action. ResultsOur data revealed a significant inhibitory effect of ISE Ⅱ on the upregulation of α-smooth muscle actin (α-SMA) and collagen production induced by TGF-β1 in fibroblasts. Meanwhile, ISE Ⅱ exerted a therapeutic effect against bleomycin-induced pulmonary fibrosis in mice by improving lung function, decreasing collagen deposition, and reducing the expression of interleukin (IL)-1β, tumor necrosis factor α (TNF-α), TGF-β1 and platelet-derived growth factor (PDGF) in serum and bronchoalveolar lavage fluid (BALF). Additionally, ISE Ⅱ treatment effectively attenuated the infiltration of M2 macrophages, concurrently downregulating the expression level of M2 marker genes, such as CD206, arginase-1(Arg-1), and Chitinase-Like Protein 3 (YM-1). Importantly, we observed a statistically significant reduction in the M2 phenotype of interstitial macrophages (IMs). However, the impact of ISE Ⅱ on the M2 polarization of alveolar macrophages (AMs) did not reach statistical significance. Lastly, transcriptome sequencing results suggested that the anti-pulmonary fibrosis effects of ISE Ⅱ may be mediated by the suppression of the WNT/β-catenin signaling pathway, which modulated M2 polarization in macrophages and contributed to the amelioration of pulmonary fibrosis. By immunohistochemical analysis, it was verified that ISE Ⅱ treatment dramatically inhibited the activation of β-catenin in fibrosis murine. ConclusionOur findings indicated that ISE Ⅱ exerted anti-fibrotic effects by inhibiting pro-fibrotic macrophage polarization. The underlying mechanism of action might be mediated by modulating the WNT/β-catenin signaling pathway to inhibit the M2 program in IMs.

TMT proteomics analysis reveals the mechanism of bleomycin-induced pulmonary fibrosis and effects of Ginseng honeysuckle superfine powdered tea

BackgroundPulmonary fibrosis (PF) is a chronic and potentially fatal lung disease and disorder. Although the active ingredients of ginseng honeysuckle superfine powdered tea (GHSPT) have been proven to have anti-inflammatory and antioxidant effects, the mechanism of GHSPT on PF remains unclear. The present study was to explore the underlying mechanism of GHSPT in treating PF based on proteomics and network pharmacology analysis and to confirm it in vivo.Materials and methodsWe used intratracheal instillation of bleomycin to induce the PF mouse model and GHSPT (640 mg/kg) intragastrically administrated to PF mice for 21 days. The lung tissues were harvested for TMT-based proteomics. The UPLC-Q-Exactive MS/MS analyze the serum migrant compounds of GHSPT in the PF mice. Moreover, components of GHSPT were harvested from the pharmacology database of the TCMSP system. PF-related targets were retrieved using NCBI and GeneCards databases.ResultsOur results showed that GHSPT significantly alleviated PF mice. Proteomics analysis showed that 525 proteins had significantly changed in the lung of untreated PF mice. Among them, 19 differential proteins were back-regulated to normal levels after GHSPT therapy. Moreover, 25 compounds originating from GHSPT were identified in the serum sample. Network analysis showed 159 active ingredients and 92 drug targets against PF. The signaling pathways include apoptosis, ferroptosis, cytokine-cytokine receptor, P53, and PI3K-Akt signaling pathway.ConclusionThe evidence suggests that GHSPT might play an effective role in the treatment of PF by multi-target interventions against multiple signaling pathways.