Earthworm extract attenuates silica-induced pulmonary fibrosis through Nrf2-dependent mechanisms

Pharmacological effects of bioactive agents in earthworm extract: A comprehensive review

This review compiles information from the literature on the chemical composition, pharmacological effects, and molecular mechanisms of earthworm extract (EE) and suggests possibilities for clinical translation of EE. We also consider future trends and concerns in this domain. We summarize the bioactive components of EE, including G-90, lysenin, lumbrokinase, antimicrobial peptides, earthworm serine protease (ESP), and polyphenols, and detail the antitumor, antithrombotic, antiviral, antibacterial, anti-inflammatory, analgesic, antioxidant, wound-healing, antifibrotic, and hypoglycemic activities and mechanisms of action of EE based on existing in vitro and in vivo studies. We further propose the potential of EE for clinical translation in anticancer and lipid-modifying therapies, and its promise as source of a novel agent for wound healing and resistance to antibiotic tolerance. The earthworm enzyme lumbrokinase embodies highly effective anticoagulant and thrombolytic properties and has the advantage of not causing bleeding phenomena due to hyperfibrinolysis. Its antifibrotic properties can reduce the excessive accumulation of extracellular matrix. The glycolipoprotein extract G-90 can effectively scavenge reactive oxygen groups and protect cellular tissues from oxidative damage. Earthworms have evolved a well-developed defense mechanism to fight against microbial infections, and the bioactive agents in EE have shown good antibacterial, fungal, and viral properties in in vitro and in vivo experiments and can alleviate inflammatory responses caused by infections, effectively reducing pain. Recent studies have also highlighted the role of EE in lowering blood glucose. EE shows high medicinal value and is expected to be a source of many bioactive compounds.

Water extract of earthworms mitigates mouse liver fibrosis by potentiating hepatic LKB1/Nrf2 axis to inhibit HSC activation and hepatocyte death

ETHNOPHARMACOLOGICAL RELEVANCE

When left untreated, liver fibrosis (LF) causes various chronic liver diseases. Earthworms (Pheretima aspergillum) are widely used in traditional medicine because of their capacity to relieve hepatic diseases.

AIM OF THE STUDY

This study aimed to explore the anti-LF effects of water extract of earthworms (WEE) and the underlying molecular mechanisms.

MATERIALS AND METHODS

A CCl4-induced mouse model of LF was used to study the impact of WEE on LF in vivo. The anti-LF activity of WEE in mice was compared with that of silybin, which can be clinically applied in LF intervention and was used as a positive control. Activation of LX-2 hepatic stellate cells (HSCs) and apoptosis and ferroptosis of AML-12 hepatocytes induced by TGFβ1 were used as in vitro models.

RESULTS

WEE drastically improved LF in mice. WEE reduced markers of activated HSCs in mice and inhibited TGFβ1-induced activation of LX-2 HSCs in vitro. Additionally, WEE suppressed CCl4-induced apoptosis and ferroptosis in mouse hepatocytes. Mechanistically, WEE induced Nrf2 to enter the nuclei of the mouse liver cells, and the hepatic levels of Nrf2-downstream antioxidative factors increased. LKB1/AMPK/GSK3β is an upstream regulatory cascade of Nrf2. In the LF mouse model, WEE increased hepatic phosphorylated LKB1, AMPK, and GSK3β levels. Similar results were obtained for the LX-2 cells. In AML-12 hepatocytes and LX-2 HSCs, WEE elevated intracellular Nrf2 levels, promoted its nuclear translocation, and inhibited TGFβ1-induced ROS accumulation. Knocking down LKB1 abolished the impact of WEE on the AMPK/GSK3β/Nrf2 cascade and eliminated its protective effects against TGFβ1.

CONCLUSIONS

Our findings reveal that WEE improves mouse LF triggered by CCl4 and supports its application as a promising hepatoprotective agent against LF. The potentiation of the hepatic antioxidative AMPK/GSK3β/Nrf2 cascade by activating LKB1 and the subsequent suppression of HSC activation and hepatocyte apoptosis and ferroptosis are implicated in WEE-mediated alleviation of LF.

CircZNF609 regulates pulmonary fibrosis via miR-145-5p/KLF4 axis and its translation function

BACKGROUND

Pulmonary fibrosis is a growing clinical problem that develops as a result of abnormal wound healing, leading to breathlessness, pulmonary dysfunction and ultimately death. However, therapeutic options for pulmonary fibrosis are limited because the underlying pathogenesis remains incompletely understood. Circular RNAs, as key regulators in various diseases, remain poorly understood in pulmonary fibrosis induced by silica.

METHODS

We performed studies with fibroblast cell lines and silica-induced mouse pulmonary fibrosis models. The expression of circZNF609, miR-145-5p, and KLF4 was determined by quantitative real-time polymerase chain reaction (qRT-PCR) analysis. RNA immunoprecipitation (RIP) assays and m6A RNA immunoprecipitation assays (MeRIP), Western blotting, immunofluorescence assays, and CCK8 were performed to investigate the role of the circZNF609/miR-145-5p/KLF4 axis and circZNF609-encoded peptides in fibroblast activation.

RESULTS

Our data showed that circZNF609 was downregulated in activated fibroblasts and silica-induced fibrotic mouse lung tissues. Overexpression of circZNF609 could inhibit fibroblast activation induced by transforming growth factor-β1 (TGF-β1). Mechanically, we revealed that circZNF609 regulates pulmonary fibrosis via miR-145-5p/KLF4 axis and circZNF609-encoded peptides. Furthermore, circZNF609 was highly methylated and its expression was controlled by N6-methyladenosine (m6A) modification. Lastly, in vivo studies revealed that overexpression of circZNF609 attenuates silica-induced lung fibrosis in mice.

CONCLUSIONS

Our data indicate that circZNF609 is a critical regulator of fibroblast activation and silica-induced lung fibrosis. The circZNF609 and its derived peptides may represent novel promising targets for the treatment of pulmonary fibrosis.

Bushen Tongluo formula ameliorated testosterone propionate-induced benign prostatic hyperplasia in rats

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common disease in older men worldwide. However, there is currently no effective treatment for BPH. Bushen Tongluo Formula (Kidney-supplementing and collaterals-unblocking formula [KCF]) is a traditional Chinese medicine formula commonly used to ameliorate the symptoms of BPH, although the specific molecular mechanisms remain unclear.

PURPOSE

We aimed to discover the effects and potential mechanisms of KCF against BPH.

METHODS

Sixty male SD rats were randomly assigned to one of six group (n = 10): control, low-dosage KCF, medium-dosage KCF, high-dosage KCF, BPH model, and finasteride. A rat model of BPH was established by surgical castration followed by subcutaneous injection of testosterone propionate (TP) for 4 weeks. After treatment, the prostate index, histopathological staining, serum levels of estradiol (E2) and dihydrotestosterone (DHT), protein/mRNA levels of E-cadherin, TGF-β1, caspase-3, Ki67, and vimentin, abundances of serum metabolites, and the proliferation, cell cycle, and apoptosis of BPH-1 cells were documented.

RESULTS

KCF treatment for 4 weeks reduced the prostate volume and prostate index, alleviated histopathological changes to the prostate of rats with TP-induced BPH, decreased serum levels of E2 and DHT, reduced protein/mRNA levels of TGF-β1 and vimentin, and increased E-cadherin levels. Moreover, KCF-spiked serum inhibited proliferation of BPH-1 cells, blocked the cell cycle, and promoted apoptosis. KCF was also found to regulate the contents of three metabolites (D-maltose, citric acid, and fumaric acid).

CONCLUSION

The present study was the first to report that KCF exhibited therapeutic effects against BPH by regulating energy metabolism and inhibiting epithelial-mesenchymal transition in prostate tissues. Hence, KCF presents a viable treatment option for BPH.

From Basic Research to Clinical Practice: Considerations for Treatment Drugs for Silicosis

Silicosis, characterized by irreversible pulmonary fibrosis, remains a major global public health problem. Nowadays, cumulative studies are focusing on elucidating the pathogenesis of silicosis in order to identify preventive or therapeutic antifibrotic agents. However, the existing research on the mechanism of silica-dust-induced pulmonary fibrosis is only the tip of the iceberg and lags far behind clinical needs. Idiopathic pulmonary fibrosis (IPF), as a pulmonary fibrosis disease, also has the same problem. In this study, we examined the relationship between silicosis and IPF from the perspective of their pathogenesis and fibrotic characteristics, further discussing current drug research and limitations of clinical application in silicosis. Overall, this review provided novel insights for clinical treatment of silicosis with the hope of bridging the gap between research and practice in silicosis.

Effect of Pheretima aspergillum on reducing fibrosis: A systematic review and meta-analysis

Background: Pheretima aspergillum (common name: Earthworm, Chinese name: dilong) has been used in traditional Chinese medicine for thousands of years. Recently, a few scientific studies have investigated the antifibrotic effects of Dilong extract (DE) and produced controversial results. We conducted a meta-analysis to make an informed decision on the antifibrotic effects of Dilong extract. Methods: The studies on antifibrotic effects of Dilong extract published until July 2022 in the scientific databases [PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), VIP database for Chinese Technical Periodicals, SinoMed and WanFang database] were reviewed. The RevMan 5.4.1 software was used for standardized mean difference (SMD) analysis. Two researchers independently reviewed all the studies, and their quality was assessed using the Cochrane risk of bias tool. Results: A total of 325 studies were found in the scientific databases; however, only 13 studies met the criteria for analysis. Dilong extract treatment was associated with antifibrotic effects via inhibiting the transforming growth factor beta 1 (TGF-β1, SMD = -3.16, 95% CI: -4.18, -2.14, p < .00001) and alpha-smooth muscle actin (α-SMA: SMD = -2.57, 95% CI: -3.47, -1.66, p < .00001). Conclusion: Dilong extract effectively reduces tissue fibrosis; thus, further scientific studies should be conducted to investigate and develop it for clinical use. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022357141.

An Integrated Strategy of Chemical Fingerprint and Network Pharmacology for the Discovery of Efficacy-Related Q-Markers of Pheretima

Pheretima, one of the animal-derived traditional Chinese medicines, has been wildly used in various cardiovascular and cerebrovascular diseases, including stroke, coronary heart disease, hyperlipidemia, and hyperglycemia. However, it was still a big challenge to select the quality markers for Pheretima quality control. The fingerprint and network pharmacology-based strategy was proposed to screen the efficiency related quality markers (Q-Markers) of Pheretima. The ratio of sample to liquid, ultrasonic-extraction time, temperature, and power were optimized by orthogonal design, respectively. The chemical fingerprint of forty batches of Pheretima was established, and six common peaks were screened. The network pharmacology was used to construct the Pheretima-Components-Targets-Pathways-Stroke network. It was found that six potential efficacy Q-markers in Pheretima could exert the relaxing meridians effect to treat stroke through acting on multiple targets and regulating various pathways. A simple HPLC-DAD method was developed and validated to determine the efficacy Q-markers. Grey relational analysis was used to further verify the relation of potential efficiency related quality markers with the anticoagulation activity of Pheretima, which indicated that the contents of these markers exhibited high relationship with the anticoagulation activity. It was concluded that hypoxanthine, uridine, phenylalanine, inosine, guanosine, and tryptophan were selected as quality markers related to relaxing meridians to evaluate the quality of Pheretima. The fingerprint and network pharmacology-based strategy was proved to be a powerful strategy for the discovery of efficiency related Q-markers of Pheretima.

Transcriptome-wide association study identifies PSMB9 as a susceptibility gene for coal workers' pneumoconiosis

Coal workers' pneumoconiosis (CWP) is a type of typical occupational lung disease caused by prolonged inhalation of coal mine dust. The individuals' different genetic background may underlie their different susceptibility to develop pneumoconiosis, even under the same exposure level. This study aimed to identify susceptibility genes associated with CWP. Based on our previous genome-wide association study (GWAS, 202 CWP cases vs. 198 controls) and gene expression data obtained by analyzing human lungs and whole blood from the Genotype-Tissue Expression (GTEx) Portal, a transcriptome-wide association study (TWAS) was applied to identify CWP risk-related genes. Luciferase report gene assay, qRT-PCR, Western blot, immunofluorescence assay, and TUNEL assay were conducted to explore the potential role of the candidate gene in CWP. Proteasome 20S subunit beta 9 (PSMB9) was identified as a strong risk-related gene of CWP in both lungs and whole blood (Lungs: P_TWAS  = 4.22 × 10^-4 ; Whole blood: P_TWAS  = 2.11 × 10^-4 ). Single nucleotide polymorphisms (SNPs) rs2071480 and rs1351383, which locate in the promoter region and the first intron of the PSMB9 gene, were in high linkage disequilibrium (LD, r²  = 0.98) with the best GWAS SNP rs4713600 (G>T, OR = 0.55, 95% CI: 0.42-0.74, P = 6.86 × 10^-5 ). Both rs2071480 and rs1351383 significantly enhanced the transcriptional activity of PSMB9. Functional experiments revealed that silica exposure remarkably reduced the PSMB9 expression and caused cell apoptosis, while overexpression of PSMB9 markedly abolished silica-induced cell apoptosis. We here identified PSMB9 as a novel susceptibility gene for CWP and provided important insights into the further exploration of the CWP pathogenesis.

Integrative transcriptomic and proteomic analysis reveals mechanisms of silica-induced pulmonary fibrosis in rats

Background

Silicosis is a systemic disease characterized by persistent inflammation and incurable pulmonary fibrosis. Although great effort has been made to understand the pathogenesis of the disease, molecular mechanism underlying silicosis is not fully elucidated. This study was aimed to explore proteomic and transcriptomic changes in rat model of silicosis.

Methods

Twenty male Wistar rats were randomly divided into two groups with 10 rats in each group. Rats in the model group were intratracheally instilled with 50 mg/mL silicon dioxide (1 mL per rat) and rats in the control group were treated with 1.0 mL saline (1 mL per rat). Twenty-eight days later, transcriptomic analysis by microarray and tandem mass tags (TMT)-based proteomic analysis were performed to reveal the expression of mRNAs and proteins in lung tissues. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were applied to analyze the altered genes and proteins. The integrated analysis was performed between transcriptome and proteome. The data were further verified by RT-qPCR and parallel reaction monitoring (PRM).

Results

In total, 1769 differentially expressed genes (DEGs) and 650 differentially expressed proteins (DEPs) were identified between the silicosis model and control groups. The integrated analysis showed 250 DEPs were correlated to the corresponding DEGs (cor-DEPs-DEGs), which were mainly enriched in phagosome, leukocyte transendothelial migration, complement and coagulation cascades and cellular adhesion molecule (CAM). These pathways are interrelated and converged at common points to produce an effect. GM2a, CHI3L1, LCN2 and GNAI1 are involved in the extracellular matrix (ECM) and inflammation contributing to fibrosis.

Conclusion

Our comprehensive transcriptome and proteome data provide new insights into the mechanisms of silicosis and helpful information for more targeted prevention and treatment of silicosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01807-w.

Genome-wide mRNA profiling identifies the NRF2-regulated lymphocyte oxidative stress status in patients with silicosis

BACKGROUND

The immunomodulatory abnormalities of silicosis are related to the lymphocyte oxidative stress state. The potential effect of antioxidant therapy on silicosis may depend on the variation in nuclear factor erythroid 2-related factor 2 (NRF2)-regulated antioxidant genes in peripheral blood mononuclear cells (PBMCs). As NRF2 is a redox-sensitive transcription factor, its possible roles and underlying mechanism in the treatment of silicosis need to be clarified.

METHODS

Ninety-two male patients with silicosis and 87 male healthy volunteers were randomly selected. PBMCs were isolated from fresh blood from patients with silicosis and healthy controls. The lymphocyte oxidative stress state was investigated by evaluating NRF2 expression and NRF2-dependent antioxidative genes in PBMCs from patients with silicosis. Key differentially expressed genes (DEGs) and signaling pathways were identified utilizing RNA sequencing (RNA-Seq) and bioinformatics technology. Gene set enrichment analysis was used to identify the differences in NRF2 signaling networks between patients with silicosis and healthy controls.

RESULTS

The number of monocytes was significantly higher in patients with silicosis than that of healthy controls. Furthermore, RNA-Seq findings were confirmed using quantitative polymerase chain reaction and revealed that NRF2-regulated DEGs were associated with glutathione metabolism, transforming growth factor-β, and the extracellular matrix receptor interaction signaling pathway in PBMCs from patients with silicosis. The top 10 hub genes were identified by PPI analysis: SMAD2, MAPK3, THBS1, SMAD3, ITGB3, integrin alpha-V (ITGAV), von Willebrand factor (VWF), BMP4, CD44, and SMAD7.

CONCLUSIONS

These findings suggest that NRF2 signaling regulates the lymphocyte oxidative stress state and may contribute to fibrogenic responses in human PBMCs. Therefore, NRF2 might serve as a novel preventive and therapeutic candidate for silicosis.

miR-770-5p inhibits the activation of pulmonary fibroblasts and silica-induced pulmonary fibrosis through targeting TGFBR1

Silicosis is a devastating interstitial lung disease arising from long-term exposure to inhalable silica. Regrettably, no therapy currently can effectively reverse the silica-induced fibrotic lesion. Emerging evidence has indicated that the dysregulation of microRNAs is involved in silica-induced pulmonary fibrosis. The aim of this study is to explore the expression pattern and underlying mechanisms of miR-770-5p in silica-induced pulmonary fibrosis. Consistent with our previous miRNA microarray analysis, the results of qRT-PCR showed that miR-770-5p expression was downregulated in silica-induced pulmonary fibrosis in humans and animal models. Administration of miR-770-5p agomir significantly reduced the fibrotic lesions in the lungs of mice exposed to silica dust. MiR-770-5p also exhibited a dramatic reduction in TGF-β1-activated human pulmonary fibroblasts (MRC-5). Transfection of miR-770-5p mimics significantly decreased the viability, migration ability, and S/G0 phase distribution, as well as the expression of fibronectin, collagen I, and α-SMA in TGF-β1-treated MRC-5 cells. Transforming growth factor-β receptor 1 (TGFBR1) was confirmed as a direct target of regulation by miR-770-5p. The expression of TGFBR1 was significantly increased in pulmonary fibrosis. Knockdown of TGFBR1 blocked the transduction of the TGF-β1 signaling pathway and attenuated the activation of MRC-5 cells, while overexpression of TGFBR1 effectively restored the activation of MRC-5 cells inhibited by miR-770-5p. Together, our results demonstrated that miR-770-5p exerted an anti-fibrotic effect in silica-induced pulmonary fibrosis by targeting TGFBR1. Targeting miR-770-5p might provide a new therapeutic strategy to prevent the abnormal activation of pulmonary fibroblasts in silicosis.

n-BuOH extract of Bletilla striata exerts chemopreventive effects on lung against SiO2 nanoparticles through activation of Nrf2 pathway

BACKGROUND

SiO₂ nanoparticles (nm SiO₂) are ubiquitous in daily life and are acknowledged to be detrimental to human health. Bletilla striata is a traditional medicine used for generations in China and its polysaccharide has the anti-pulmonary fibrosis effect.

PURPOSE

To investigate the lung protective effect of the small molecules (n-BuOH extract) of B. striata and clarify the underlying mechanism.

STUDY DESIGN AND METHODS

C57BL/6 mice were subjected to intratracheal instillation with nm SiO₂ nanoparticle suspension (7 mg/kg) to construct the in vivo model of nm SiO₂-induced lung injury. The chemical profile of the n-BuOH extract of B. striata was investigated by HPLC analysis using authentic samples isolated from B. striata. Gymnoside II with the most potent chemoprotective capacity in the n-BuOH extract was used to clarify the potential bio-active molecular basis of the n-BuOH extract using in vitro experiments. The cytotoxicity, apoptosis, oxidative stress, and the Nrf2 signaling pathway were examined in SiO₂-induced A549 cells. ML385 was adopted to down-regulate the Nrf2 expression.

RESULTS

The n-BuOH extract of B. striata (40 mg/kg) could alleviate the SiO₂-induced lung injury by increasing Nrf2 expression and thereby suppressing Bax/Bcl-2 pathway in the nm SiO₂-induced mice model. The chemical profile study showed that militarine, gymnoside II, and 4-allyl-2, 6-dimethoxyphenol glucoside were the main constituents of n-BuOH extract. Studies on gymnoside II revealed that it could partially restore the SiO₂-induced decline in cell viability while did not affect the growth of normal A549 cells within the concentration range of 1-50 μM, suggesting a protective effect against nm SiO₂ in lung A549 cells. The hoechst 33258 staining, flow cytometry, and western blot experiments demonstrated that gymnoside II (25 μM) could partially reverse the SiO₂-induced cell apoptosis and ROS production by enhancing Nrf2, HO-1, and γ-GCSc expressions and Nrf2 silencing by ML385 abrogated the effects of gymnoside II (25 μM) on apoptosis and ROS production in A549 cells.

CONCLUSION

The present study suggests that in addition to the polysaccharide, small molecules (n-BuOH extract) of B. striata can also elicit a protective effect on lung injuries through the Nrf2-dependent mechanism and gymnoside II is one of the main bio-active constituents contributing to the n-BuOH extract-elicited lung protective effect against nm SiO₂.

Time- and Dose-Resolved Proteome of PM2.5-Exposure-Induced Lung Injury and Repair in Rats

In recent years, airborne fine particulate matter (PM_2.5) is drawing more public attention due to its various physicochemical features and causing pathological harm, as proven by epidemiological and clinical studies. However, the mechanism of PM_2.5-exposure-induced lung injury has not been fully characterized. Here, we established a PM_2.5-induced rat injury model for both short-term and long-term exposures at different concentrations. We employed the Fast-seq technique to profile 6316 proteins and the catTFRE approach to profile 387 transcription factors (TFs) in the lung tissue. In short-term exposure, we elucidated gradually upregulated proteins enriched in response to oxidative stress, phagosome, and the extracellular matrix (ECM)-receptor interaction pathway. Long-term exposure mainly showed the immune response pathway to be consisting of increased lymphocytes and cytokines. Intriguingly, we found that immune-related proteins were recoverable during short-term exposure. During the process of PM_2.5 exposure, upregulated proteins presented dose-dependence in the lung, including stress response at low dose, minor immune response at middle dose, and severe inflammatory response at high dose. This data set provides a rich resource to facilitate the understanding of PM_2.5-induced lung damage and repair mechanism.

Elk-1 transcriptionally regulates ZC3H4 expression to promote silica-induced epithelial-mesenchymal transition

The epithelial-mesenchymal transition (EMT) process is a key priming activity of fibroblasts in pulmonary fibrosis during silicosis. Ets-like protein-1 (Elk-1) is a critical modulator that promotes functional changes in cells, and the effects are mediated by oxidative stress (OS). However, whether ELK-1 is involved in EMT of silicosis remains unclear. In addition, researchers have found that Elk-1 is involved in the expression of the gene zc3h12a, which encodes the protein MCPIP1, and MCPIP1 is a member of the zinc finger Cys-Cys-Cys-His (CCCH)-type protein family. A previous study from our lab showed that ZC3H4, which is also a member of the CCCH-type protein family, critically affected the regulation of EMT during silicosis. However, it has not yet been elucidated if ELK-1 acts at the promoter for zc3h4 to increase its expression in a mechanism that is similar to that of the zc3h12a gene and whether such regulation ultimately controls EMT. Therefore, we explored the correlation between ELK-1 and ZC3H4 expression and tested the underlying mechanisms affecting ELK-1 activation induced by silica. Our study identifies that SiO₂-mediated EMT via ELK-1, with the upstream activity of OS and the downstream signaling of ZC3H4 expression resulting in enhanced EMT. These findings suggest that the nuclear transcription factor ELK-1 may be useful as a novel target for the treatment of pulmonary fibrosis.

Overexpression of endogenous lipoic acid synthase attenuates pulmonary fibrosis induced by crystalline silica in mice

Oxidative stress and inflammatory processes are proposed to mediate the development of silicosis. However, antioxidant therapy has not produced consistent results during the treatment of silicosis. α-Lipoic acid synthesized by lipoic acid synthase is a powerful anti-oxidant and helps protect mitochondria. Thus far, the effect of endogenous α-Lipoic acid on silicosis has not been elucidated yet. We established an experimental model of silicosis with wildtype and Lias^H/H mice, a new antioxidant mouse model which has overexpressed Lias gene (∼150 %) relative to its wild type counterpart. We systemically examined main pathological changes of pulmonary fibrosis, and explored α-lipoic acid effects on oxidative stress, inflammatory and pulmonary fibrosis biomarkers in silica-instillated mice. In Lias^H/H mice over-expression of lipoic acid alleviated the severity of major pathological alterations in the early stage of pulmonary fibrosis induced by silica compared with wild type mice. Silica significantly increased oxidative stress in both wild type and Lias^H/H mice. The antioxidant defense was strengthen including increased NRF2 and LIAS production in Lias^H/H mice. Relieved oxidative stress resulted in decreased inflammatory response and secretion of chemokines. Lias^H/H mice reduced chronic inflammatory response and inhibition of NF-κB activity after silica instillation. The Lias^H/H mouse model overexpression of lipoic acid synthase gene retarded the development of silica-induced pulmonary fibrosis. Strengthen antioxidant defense by increased lipoic acid synthase is a potential strategy for protection against silica-induced pulmonary fibrosis.

The effect of earthworm extract on mice S180 tumor growth and apoptosis

Great efforts have been made to explore the potential treatment for cancers, and the most common therapies include surgery, chemotherapy and radiotherapy. As an alternative medication, earthworms have drawn increased attention considering its abundance in resource, easy access and minor side effects compared to traditional therapies. However, few studies had focused on the antitumor effect of earthworm-derived components. The purpose of this study is to investigate whether earthworm extract has an effect on tumor cell apoptosis and growth. Earthworm extract (EE) was purified through multiple steps of centrifugation and chromatography. Mice were inoculated with ascitic fluid derived from mice inoculated with S180 sarcoma tumor cells and fed orally with different amounts of EE for 25 days. Tumor samples were analyzed for size and cell apoptosis. And we found that the weight and sizes of tumor decreased gradually as the amount of EE administered increased. More apoptotic cells and lowered level of lactate dehydrogenase (LDH), a biomarker of tumor invasiveness, was detected in EE-treated group than the untreated group. Our results suggested that EE could dramatically promote tumor apoptosis and reduce tumor size in vivo, suggesting a novel alternative therapy for cancer patients.

Vitamin D protects against particles-caused lung injury through induction of autophagy in an Nrf2-dependent manner

Fine particulate matter is a well-known air pollutant threatening public health. Studies have confirmed long-term exposure to the particles could decrease the pulmonary function, induce asthma exacerbation, and chronic obstructive pulmonary disease, as well as increase the incidence and mortality of lung cancer. A clinical study has explored that the prevalence and risks of vitamin D (VD) deficiency in various chronic disease and toxins induced tissue damage. Our current study aimed to explore the mechanism and further therapeutic potential of VD administration to ameliorate fine particles exposure induced pulmonary damage in vivo and in vitro. To elucidate the effects and mechanisms of VD in particles-induced pulmonary damage, a murine model was established with fine particles intratracheal instillation along with VD intramuscular injection. Our study demonstrated that treatment with VD attenuated particles-induced pulmonary damage and promoted tissue repair by repressing of TGFβ1 signaling pathway and upregulation of MMP9 expression. VD treatment could also regulate the autophagy-related signals along with activation of Nrf2 transcription factor. Furthermore, the results from the in vitro study demonstrated that VD protected against particles-induced cells' damage through the induction of autophagy in an Nrf2-dependent manner. VD treatment caused the degradation of P62 and its bound Keap1, which decreased the Nrf2 ubiquitination and increasing its protein stability. Our work explored a novel potential mechanism in the protection of VD in particles-induced pulmonary injury and tissue repair, and could further bring insights into exploring antifine particles exposure caused inflammation among other natural products and contributes to inflammation disease medical therapies.

Profiling long non-coding RNA changes in silica-induced pulmonary fibrosis in rat

Silicosis is a kind of chronic and incurable lung fibrotic disease with pathogenesis and molecular mechanisms largely unknown. Mounting evidence suggests that long non-coding RNAs (lncRNAs) are involved in the pathogenesis of silicosis. However, how many lncRNAs involved in the pulmonary fibrosis remains to be elucidated. In this study, Wistar rats were exposed to silicon dioxide by an improved tracheal intubation method. Rats in the control group were treated with normal saline solution. Results showed that 28 days after exposure, there were significant differences in body weight and lung coefficient of rats treated with silica compared with control rats. The formation of lung fibrosis in silica-induced rats was confirmed by histologic examination. We then investigated the lncRNAs expression changes in lung tissues of silica-exposed rats and compared that with the rats in the control group using microarray. The results indicated that silica exposure leads to altered expression profile in 682 lncRNAs (300 upregulated and 382 downregulated). Seventy-three ceRNA pairs were acquired by predicted analysis. Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology analyses were used to predict the biological pathway and functional classification of lncRNAs. The results showed that silica exposure affected 13 lncRNAs pathways. The functional classification mainly involved in protein binding, cell shape and extracellular exosome. This study indicated that alteration of lncRNAs may play a role in silica-induced pulmonary fibrosis through regulation of expressions of functional genes in lungs of rat. Our results provide more insights into the mechanism of silicosis.

Therapeutic potential of bixin in PM2.5 particles-induced lung injury in an Nrf2-dependent manner

Fine particulate matter (PM 2.5) is a well-known air pollutant threatening public health. Studies has confirmed that long-term exposure to the particles could reduce the pulmonary function, cause exacerbation of asthma and chronic obstructive pulmonary disease, and increase incidence and mortality of lung cancer. Bixin is a natural compound that is widely used as a food additive. Our previous studies demonstrated that bixin i.p. administration could protect against particles intratracheal exposure (56 days)-induced lung injury in an Nrf2-dependent manner. But the detail mechanisms are still unclarified. Our current study aimed to explore the further therapeutic potential and mechanism of bixin to slow the progression of lung injury and inflammation in vivo and in vitro. The results from the in vivo study showed that bixin treatment attenuated the accumulation of inflammatory cells, decreased the levels of tissue apoptosis, and increase the ability of cell proliferation. Besides that, bixin also could regulate the expression of MMP9, TGFβ1, and its downstream Fibronectin (FN), along with activation of Nrf2 signals. In vitro experiments in human bronchial epithelial cells demonstrated that Nrf2 activated by bixin contributes to tissue repair by alleviating oxidative stress, increasing proliferation and migration, decreasing apoptosis, which may be partially through modulating the expression of MMP9, TGFβ1, and FN. This study provides convincing experimental evidences that bixin could be used therapeutically to promote tissue repair and improve pulmonary injury induced by particles exposure.

Immunological responses of European badgers (Meles Meles) to infection with Mycobacterium bovis

Mycobacterium bovis is the main cause of bovine tuberculosis and its eradication is proving difficult in many countries because of wildlife reservoirs, including European badgers (Meles meles) in the UK Ireland. Following the development of badger specific immunological reagents, many studies have shown that some aspects of the cellular and serological immune responses of badgers to virulent M. bovis and the attenuated M. bovis BCG (Bacille of Calmette and Guérin) strain are similar to those seen in other animal hosts infected with M. bovis. However, badgers also appear to have developed specific immunological responses to M. bovis infection which may be associated with mild inflammatory responses. Badgers may therefore represent an interesting natural host for M. bovis that can provide a more thorough understanding of efficient immunological responses to tuberculosis.

Bixin protects against particle-induced long-term lung injury in an NRF2-dependent manner

Scope: Particle-induced lung injury is a kind of comprehensive pulmonary disease with not only inflammation but also fibrosis. Bixin is a natural compound that is widely used as a food additive. Our previous studies demonstrated that bixin could alleviate inflammation in ventilation-induced acute lung injury as well as UV-exposure caused skin damage. But whether it could depress silica-induced long-term comprehensive lung injury and the mechanism of bixin in this protection have not yet been studied. Methods: A murine SiO2-induced long-term comprehensive lung injury model was established through silica intratracheal instillation. To elucidate the effects and mechanisms of bixin in silica-induced pulmonary inflammation and fibrosis, we treated mice with bixin following silica instillation. Results: Bixin treatment attenuated the accumulation of inflammatory cells which significantly ameliorated pathological inflammation and fibrotic development in the lungs. In addition, intraperitoneal (i.p.) injection of bixin in mice led to the upregulation of the NRF2 response in the lungs. Since alveolar macrophage activation plays a vital role in the initiation and progression of this injury, the mechanism was further studied in the THP-1 macrophage cells. Bixin activated NRF2 signals via blocking KEAP1 mediated ubiquitylation and degradation of NRF2. Conclusions: Our work has brought insights into exploring anti-particle-induced lung injury activities in the daily consumption of natural products. In addition, our study also inspires the discovery of new beneficial effects of bixin and its application in the treatment of other inflammatory diseases.

miR-1224-5p Mediates Mitochondrial Damage to Affect Silica-Induced Pulmonary Fibrosis by Targeting BECN1

Silicosis is associated with fibroblast proliferation and extracellular matrix deposition in lung tissues. The dysregulation of miR-1224-5p has been implicated in several human cancers; however, the expression and function of miR-1224-5p in silicosis is unknown. The mitochondrial dysfunctions play critical roles in some diseases, but how these processes are regulated in silicosis remains limited. Here, we explored the role of miR-1224-5p in a mouse model of silicosis. We showed that the expression of miR-1224-5p is increased both in lung tissues of silica-induced pulmonary fibrosis and fibroblasts exposed to TGF-β1. Repression of miR-1224-5p expression attenuated silica-induced fibrotic progression in vivo and TGF-β1-induced myofibroblast differentiation in vitro. Additionally, we demonstrated that miR-1224-5p facilitated silica-induced pulmonary fibrosis primarily by repressing one of target genes, BECN1, thereby blocking PARK2 translocation to mitochondria and inducing the accumulation of damaged mitochondria. Furthermore, the activation of PDGFR signal mediated by mitochondrial damage and insufficient mitophagy resulted in myofibroblast differentiation. Collectively, these data indicated that miR-1224-5p exerts key functions in silica-induced pulmonary fibrosis and may represent a potential therapeutic target for silicosis.

Long non-coding RNA-ATB promotes EMT during silica-induced pulmonary fibrosis by competitively binding miR-200c

Long non-coding RNAs (lncRNAs) are important signal transduction regulators that act by various patterns. However, little is known about the molecular mechanisms of lncRNA related pathways in occupational lung fibrosis. Our previous study found that epithelial-mesenchymal transition (EMT) was one of the key events in silica-induced pulmonary fibrosis. This study showed that the lncRNA-ATB promoted EMT by acting as a miR-200c sponge. miR-200c was identified by miRNA array as a potential target of lncRNA-ATB and verified by dual luciferase reporter gene together with RNA pull-down assays. Moreover, our findings demonstrated that lncRNA-ATB is abundantly expressed during EMT of lung epithelial cells, which contributes to decreased levels of miR-200c. miR-200c targeted ZEB1 to relief silicosis by blocking EMT in vivo and in vitro. The results also suggested M2 macrophages secreted transforming growth factor-β1 (TGF-β1) to induce EMT process by activating lncRNA-ATB in epithelial cells. Collectively, silica-stimulated macrophages secreted TGF-β1 to induce lncRNA-ATB in epithelia cells, promoting EMT by binding with miR-200c and releasing ZEB1. These observations provide further understanding of the regulatory network of silica-induced pulmonary fibrosis and identify new therapeutic targets hopefully.

Rapamycin protects against paraquat-induced pulmonary fibrosis: Activation of Nrf2 signaling pathway

Paraquat (PQ) is a widely used herbicide indeveloping countries worldwide, and pulmonary fibrosis is one of the most typical features of PQ poisoning. The molecular mechanism of PQ toxicity especially how to treat PQ-induced pulmonary fibrosis is still largely unknown. In animal model of pulmonary fibrosis, we used HE staining, western blotting assay and Real-time PCR assay to analyze the effects of rapamycin on the PQ-induced epithelial mesenchymal transition (EMT). We found that PQ induced the pulmonary fibrosis using HE staining and Masson's staining, and up-regulated the activity of HYP and the mRNA expressions of Collagen I and III (COL-1and COL-3) in pulmonary tissues. We also found that rapamycin down-regulated the mesenchymal cell marker Vimentin and up-regulated the epithelial cell marker E-cadherin both in mRNA and protein levels compared with PQ group. And the EMT associated transcription factor Snail was decreased by rapamycin treatment compared with PQ group. And PQ decreased the Nrf2 expression both in mRNA and protein levels, and rapamycin inhibited these effects of PQ. SFN, a activator of Nrf2, could inhibit the EMT and the expression of Snail. And knockdowon of Nrf2 could abolish the inhibitory effects of rapamycin of PQ-induced EMT. In conclusion, rapamycin protects against paraquat-induced pulmonary fibrosis by activation of Nrf2 signaling pathway.