Mitigation of Oxidative Stress in Idiopathic Pulmonary Fibrosis Through Exosome-Mediated Therapies.

Idiopathic pulmonary fibrosis (IPF) poses a formidable clinical challenge, characterized by the thickening of alveolar septa and the onset of pulmonary fibrosis. The pronounced activation of oxidative stress emerges as a pivotal hallmark of inflammation. Traditional application of exogenous antioxidants proves inadequate in addressing oxidative stress, necessitating exploration into strategies to augment their antioxidant efficacy. Exosomes, nano-sized extracellular vesicles harboring a diverse array of bioactive factors, present as promising carriers with the potential to meet this challenge. Recent attention has been directed towards the clinical applications of exosomes in IPF, fueling the impetus for this comprehensive review. We have compiled fresh insights into the role of exosomes in modulating oxidative stress in IPF and delved into their potential as carriers for regulating endogenous reactive oxygen species generation. This review endeavors to bridge the divide between exosome research and IPF, traversing from bedside to bench. Through the synthesis of recent findings, we propose exosomes as a novel and promising strategy for improving the outcomes of IPF therapy.

Transcriptomics Analysis Identifies the Presence of Upregulated Ribosomal Housekeeping Genes in the Alveolar Macrophages of Patients with Smoking-Induced Chronic Obstructive Pulmonary Disease.

BACKGROUND AND AIMS: Alveolar macrophages (AM) play a crucial role in the development of chronic obstructive pulmonary disease (COPD). The role that AM plays in the molecular pathways and clinical phenotypes associated with tobacco-related emphysema remain poorly understood. Thus, we investigated the transcriptomic profile of AM in COPD patients with a history of smoking and explored the molecular mechanisms associated with enriched pathways and hub genes. METHODS: Four data sets (GSE2125, GSE8823, GSE13896 and GSE130928) were retrieved from the GEO Database. A total of 203 GEO samples (GSM) were collated for this study. About 125 of these cases were classified as smokers (91 as healthy non-COPD smokers and 34 as COPD smokers). Based on the bioinformatics obtained using the R3.6.1 program, the data were successively adopted for differential genetic expression analysis, enrichment analysis (EA), and then protein-protein interaction analysis (PPI) in a STRING database. Finally, Cytoscape 3.8 software was used to screen the hub genes. A further data analysis was performed using a set of 154 cases, classified as 64 healthy non-smokers and 91 as healthy smokers. The same procedures were used as for the COPD dataset. RESULTS: When comparing the data pertaining to COPD-smokers and non-COPD smokers, the top ten genes with the greatest transcriptional differences were found to be NADK, DRAP1, DEDD, NONO, KLHL12, PRKAR1A, ITGAL, GLE1, SLC8A1, SVIL. A GSEA (Gene Set Enrichment Analysis) revealed that these genes manifested an up-regulated ribosomal pathway in contrast with other genes that exhibited an extensive down-regulated pathway. The hub genes were mainly genes encoding ribosomal subunits through PPI. Furthermore, it was found that there is a narrow transcriptional difference between healthy non-smokers and non-COPD smokers and the hub genes identified here are mainly members of the chemokines, including CCL5, CCR5, CXCL9 and CXCL11. CONCLUSION: An elevated activity of the ribosome pathway in addition to the increased expression of ribosomal housekeeping genes (also known as hub genes) were identified with COPD-smokers, and these have the potential to cause a wide range of downstream pathogenetic effects. As for the preclinical phase, non-COPD smokers were found to be characterized by enriched pathways of several chemokines in AM.

Decreased HLF Expression Predicts Poor Survival in Lung Adenocarcinoma.

BACKGROUND Lung adenocarcinoma (LUAD) is a type of non-small cell carcinoma. Its pathogenesis is being explored and there is no cure for the disease. MATERIAL AND METHODS The Gene Expression Omnibus (GEO) was searched to obtain data on expression of messenger RNA. GEO2R, an interactive web tool, was used to calculate the differentially expressed genes (DEGs) in LUAD. All the DEGs from different datasets were imported into VENNY 2.1 (https://bioinfogp.cnb.csic.es/tools/venny/index.html) to identify the intersection of the DEGs. An online analysis tool, the Database for Annotation, Visualization, and Integrated Discovery (DAVID), was used to help understand the biological meaning of DEG enrichment in LUAD. Cytoscape 3.7.2 was used to perform centrality analysis and visualize hub genes and related networks. Furthermore, the prognostic value of the hub genes was evaluated with the Kaplan-Meier plotter survival analysis tool. RESULTS The GEO database was used to obtain RNA sequencing information for LUAD and normal tissue from the GSE118370, GSE136043, and GSE140797 datasets. A total of 376 DEGs were identified from GSE118370, 248 were identified from GSE136403, and 718 DEGs were identified from GSE140797. The 10 genes with the highest degrees of expression - the hub genes - were CAV1, TEK, SLIT2, RHOJ, DGSX, HLF, MEIS1, PTPRD, FOXF1, and ADRB2. In addition, Kaplan-Meier survival evaluation showed that CAV1, TEK, SLIT2, HLF, MEIS1, PTPRD, FOXF1, and ADRB2 were associated with favorable outcomes for LUAD. CONCLUSIONS CAV1, TEK, SLIT2, HLF, MEIS1, PTPRD, FOXF1, and ADRB2 are hub genes in the DEG interaction network for LUAD and are involved in the development of and prognosis for the disease. The mechanisms underlying these genes should be the subject of further studies.

Resveratrol alleviates bleomycin-induced pulmonary fibrosis via suppressing HIF-1α and NF-κB expression.

The absence of a gold standard for treating pulmonary fibrosis makes its management challenging. We established a rat model to study the effect of resveratrol (Res) on bleomycin-induced pulmonary fibrosis. Rats were randomly divided into control, model, low-Res, middle-Res, high-Res, and dexamethasone groups and treated with various concentrations of these drugs. Rats showed typical features of pulmonary fibrosis; i.e., alveolitis, fibrous hyperplasia, and fibrosis on days 7, 14, and 28, respectively. Expression of HIF-1α and NF-κB was higher in the middle-Res, high-Res, and dexamethasone groups than in the control group, but was less than that in the model and low Res groups. We conclude that different levels of HIF-1α and NF-κB expression at different stages of pulmonary fibrosis in rats is positively correlated with the disease severity. Furthermore, resveratrol alleviates bleomycin-induced pulmonary fibrosis by suppressing HIF-1α and NF-κB expression, indicating its potential as a promising therapeutic drug candidate.

Resveratrol promotes osteogenesis and alleviates osteoporosis by inhibiting p53.

Although osteoporosis is one of the most common chronic age-related diseases, there is currently no gold standard for treatment. Evidence suggests resveratrol, a natural polyphenolic compound, may be helpful in the treatment of osteoporosis and other diseases. However, the molecular mechanisms underlying the anti-osteoporotic effects of resveratrol remain largely unknown. In the present study, KEGG pathway enrichment analysis of resveratrol-targeted genes identified 33 associated pathways, 12 of which were also involved in osteoporosis. In particular, the MDM2/p53 signaling pathway was identified as a potential key pathway among the shared pathways. In vitro experiments indicated that MDM2-mediated p53 degradation induced osteoblast differentiation, and resveratrol could partially reverse p53-dependent inhibition of osteogenic differentiation. These findings suggest resveratrol may alleviate osteoporosis at least in part by modulating the MDM2/p53 signaling pathway.

MiR-16-5p suppresses myofibroblast activation in systemic sclerosis by inhibiting NOTCH signaling.

Systemic sclerosis (SSc) is a prototypic fibrotic disease characterized by localized or diffuse skin thickening and fibrosis. Tissue fibrosis is driven by myofibroblasts, and factors affecting myofibroblast activation may also be involved in the development of SSc. In this study, we examined molecular mechanisms underlying SSc by focusing on myofibroblast activation processes. Bioinformatics analysis conducted to identify differentially expressed miRNAs (DEMs) and genes (DEGs) revealed that microRNA-16-5p (miR-16-5p) was downregulated and NOTCH2 was upregulated in SSc patients. In vitro experiments confirmed that miR-16-5p was able to bind directly to NOTCH2 and inhibit myofibroblast activation. Moreover, miR-16-5p-dependent inhibition of NOTCH2 decreased collagen and α-SMA expression. MiR-16-5p downregulation and NOTCH2 upregulation was also confirmed in vivo in SSc patients, and NOTCH2 activation promoted fibrosis progression in vitro. These results indicate that miR-16-5p suppresses myofibroblast activation by suppressing NOTCH signaling.

[miR-21 promotes pulmonary fibrosis in rats via down-regulating the expression of ADAMTS-1].

Objective To observe the effect of miR-21 on bleomycin-induced pulmonary fibrosis in rats, and explore the related mechanism. Methods Peripheral blood was collected from idiopathic pulmonary fibrosis (IPF) patients (n=20) and healthy adults (n=20). Fluorescence quantitative real-time PCR was then used to measure miR-21 expression. Forty-five SD rats were randomly divided into control group, miR-21 agomir group and miR-21 antagomir group. Each group included 15 rats. After establishment of pulmonary fibrosis models by intratracheal administration with bleomycin A5, rats in control group, miR-21 agomir group and miR-21 antagomir group were injected at caudal vein with normal saline, miR21 agomir and miR21 antagomir, respectively. All rats were sacrificed on day 28 after modeling. Subsequently, the pulmonary tissues were removed for HE and Masson staining. The mRNA and protein expressions of a disintegrin-like and metalloproteinase with thrombospondin type 1 motif (ADAMTS-1), collagen type 1 (Col1) and collagen type 3 (Col3) were detected by fluorescence quantitative real-time PCR and Western blotting. Serum was separated to examine procollagen type 1 carboxyterminal propeptide (P1CP) and procollagen type 3 aminoterminal propeptide (P3NP) concentrations by ELISA. Results The level of miR-21 in peripheral blood was higher in IPF patients than in healthy adults. The alveolitis and pulmonary fibrosis extent in miR-21 agomir group was heavier than that in the control group. However, the alveolitis and pulmonary fibrosis extent in miR-21 antagomir group was improved when compared with the control group. In comparison with the control group, ADAMTS-1 mRNA and protein expression was significantly downregulated, whereas the mRNA and protein expressions of Col1 and Col3 were significantly upregulated and serum P1CP and P3NP concentrations were elevated in miR-21 agomir group. On the contrary, the level of ADAMTS-1 mRNA and protein expression in miR-21 antagomir group was higher than that in the control group; the levels of Col1 and Col3 mRNA and protein as well as serum P1CP and P3NP concentrations in miR-21 antagomir group were lower than those in the control group. Conclusion miR-21 promotes the progression of bleomycin-induced pulmonary fibrosis in rats. The mechanism is associated with downregulation of ADAMTS-1 expression and subsequent increase of pulmonary Col1 and Col3 contents.

[Emodin alleviates pulmonary fibrosis through inactivation of TGF-ß1/ADAMTS-1 signaling pathway in rats].

Objective To explore the role of transforming growth factor-ß1 (TGF-ß1)/a disintegrin-like and metalloproteinase with thrombospondin type 1 motif (ADAMTS-1) signaling pathway in emodin's anti-pulmonary fibrosis. Methods Sixty SD rats were randomly divided into 6 groups: normal control group, sham-operated group, model group, low-dose emodin intervention group (20 mg/kg), high-dose emodin intervention group (80 mg/kg) and prednisone group (5 mg/kg). Each group included 10 animals. Rats in the latter 4 groups were intratracheally injected with bleomycin A5 to induce pulmonary fibrosis, whereas bleomycin A5 was replaced by normal saline in sham-operated group. From the second day, rats in the low- and high-dose emodin intervention groups were intragastrically treated with 2 mL of 20 and 80 mg/kg emodin, respectively. Rats in the prednisone group were intragastrically administrated with 2 mL of 5 mg/kg prednisone acetate. However, rats in the normal control and sham-operated and model groups were treated with 2 mL of normal saline. All rats were sacrificed on day 28 after modeling. Subsequently, blood and pulmonary tissue specimen were taken. The pathological changes of pulmonary tissues were observed using routine HE and Masson staining. The expressions of TGF-ß1, ADAMTS-1, collagen type 1 (Col1) and Col3 in pulmonary tissues were measured by quantitative real-time PCR and Western blotting. Serum levels of procollagen type 1 carboxy terminal propeptide (P1CP) and procollagen type 3 aminoterminal propeptide (P3NP) were detected by ELISA. Results Compare with the model group, the alveolitis and pulmonary fibrosis extent in each drug-treated group were significantly alleviated. In comparison with normal control group or sham-operated group, the mRNA and protein levels of TGF-ß1, Col1 and Col3 in pulmonary tissues and the serum levels of P1CP and P3NP increased, but the mRNA and protein levels of ADAMTS-1 decreased in model group. After treatment with low- and high-dose emodin or prednisone, the mRNA and protein levels of TGF-ß1, Col1 and Col3 in pulmonary tissues and the serum levels of P1CP and P3NP were significantly downregulated, while the mRNA and protein levels of ADAMTS-1 in pulmonary tissues were significantly upregulated as compared with the model group. Moreover, In comparison with the low-dose emodin intervention group, the above indicators were significantly improved in the high-dose emodin intervention or prednisone group. However, the above indicators were not significantly different between the high-dose emodin intervention group and the prednisone group. Conclusion Increased degradation of Col1 and Col3 in pulmonary tissues due to the inactivation of TGF-ß1/ADAMTS-1 signaling pathway may be a significant mechanism by which emodin protects rats against pulmonary fibrosis.

[Emodin inhibits the proliferation, transdifferentiation and collagen synthesis of pulmonary fibroblasts].

Objective To explore the effect of emodin on the proliferation, differentiation into myofibroblasts and collagen synthesis of pulmonary fibroblasts and the underlying mechanisms. Methods Human pulmonary fibroblasts MRC-5 were cultured in vitro, then the cells were inoculated with dimethyl sulfoxide (DMSO) added with 0, 10, 20, 40, 80 and 160 µmol/L emodin for 24, 48 and 72 hours. Inhibitory rate of cell proliferation was analyzed by MTT assay. Based on the results of cell proliferation experiment, MRC-5 cells were treated with DMSO (control group) and 40, 80 µmol/L emodin (in DMSO) for 48 hours. Fluorescence real-time quantitative PCR was then used to measure the mRNA expressions of α-smooth muscle actin (α-SMA), transforming growth factor-ß1 (TGF-ß1), a disintegrin-like and metalloproteinase with thrombospondin type 1 motif (ADAMTS-1), collagen type 1 (Col1) and collagen type 3 (Col3). The protein expressions of the above mentioned factors were also measured by Western blotting. Results In a concentration- and time-dependent manner, emodin inhibited MRC-5 cell proliferation. After 48 hours of co-culture, in comparison with control group, the mRNA and protein expression levels of α-SMA, TGF-ß1, Col1 and Col3 significantly decreased, while the mRNA and protein expression levels of ADAMTS-1 significantly increased in 40 and 80 µmol/L emodin-treated groups. Moreover, in comparison with 40 µmol/L emodin-treated group, the mRNA and protein expressions of α-SMA, TGF-ß1, Col1 and Col3 were significantly downregulated, but ADAMTS-1 mRNA and protein expressions were significantly upregulated in 80 µmol/L emodin-treated group. Conclusion Emodin can block pulmonary fibroblast proliferation and differentiation into myofibroblasts, and reduce the synthesis of Col1 and Col3 by inhibiting TGF-ß1/ADAMTS-1 signaling pathway.

[Unsaturated fatty acid of Actinidia chinesis Planch seed oil enhances the antioxidative stress ability of rats with pulmonary fibrosis through activating Keap 1/Nrf 2 signaling pathway].

OBJECTIVE: To observe the effects of unsaturated fatty acid of Actinidia chinesis Planch(USFA-ACP) seed oil on bleomycin-induced pulmonary fibrosis in rats, and to explore whether the effect is mediated by Kelch-like ECH-associated protein 1 (Keap 1)/nuclear factor-erythroid 2-related factor 2 (Nrf 2)signaling pathway. METHODS: Sixty SD rats were randomly divided into control group, model group, (60, 120, 180) mg/kg USFA-ACP seed oil treatment group and 5 mg/kg prednisone group. Each group included 10 animals. Rats in the control group were intratracheally administered with normal saline, and the rest of five groups were intratracheally administered with bleomycin A5 to establish pulmonary fibrosis models. From the second day, rats in the three USFA-ACP seed oil treatment groups were intragastrically treated with 60, 120 and 180 mg/kg USFA-ACP seed oil correspondingly. The prednisone group were intragastrically administrated with 5 mg/kg prednisone acetate. Control and model groups were treated with normal saline. All rats were sacrificed on day 28. Pulmonary tissues were then removed, and HE and Masson staining were performed. The contents of hydroxyproline (HYP), reactive oxygen species(ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px) in pulmonary tissue homogenates were measured through the commercial kits. The protein expressions of Keap 1 and Nrf2 in pulmonary tissues were analyzed using Western blotting. RESULTS: Compared with the model group, the alveolitis and pulmonary fibrosis extent in 60, 120, 180 mg/kg USFA-ACP seed oil treatment groups as well as the prednisone group were significantly alleviated, HYP, ROS and MDA contents in pulmonary tissues, Keap 1 protein expression in the cytoplasm decreased remarkably, while SOD, CAT and GSH-Px contents in pulmonary tissues, Nrf2 protein expression in the nucleus increased. Moreover, compared with 60 mg/kg USFA-ACP seed oil treatment group, the above indicators were significantly improved in 120 and 180 mg/kg USFA-ACP seed oil treatment group and prednisone group. However, there was no significant difference between 120 and 180 mg/kg USFA-ACP seed oil treatment groups and prednisone group. CONCLUSION: USFA-ACP seed oil can inhibit pulmonary fibrosis in rats, and the mechanism may be associated with the activation of the Keap1/Nrf 2 signaling pathway to increase the production of antioxidases in the pulmonary tissues.