Kurarinone Attenuates BLM-Induced Pulmonary Fibrosis via Inhibiting TGF-β Signaling Pathways

Forsythoside A regulates pulmonary fibrosis by inhibiting endothelial-to-mesenchymal transition and lung fibroblast proliferation via the PTPRB signaling

BACKGROUND

Pulmonary fibrosis (PF) is an end-stage change in many interstitial lung diseases, whereas no proven effective anti-pulmonary fibrotic treatments. Forsythoside A (FA) derived from Forsythia suspensa (Thunb.) Vahl, has been found to possess lung-protective effect. However, studies on its anti-pulmonary fibrosis effect are limited and its mechanism of action remains unknown.

PURPOSE

This study aimed to explore the underlying mechanism of FA on PF.

METHODS

Male C57BL/6 mice were randomized into normal (CON), model (BLM), pirfenidone (PFD), low- and high-dose FA (FA-L, FA-H, respectively). Except for the CON group, which was injected with the same dose of saline, the model of PF was established by intratracheal instillation of BLM, during which the survival rate and body weight changes of the mice were measured. The lung histopathology was evaluated by Hematoxylin-eosin, Sirius red, and Masson staining. Transcriptome analysis was performed to screen for the differential genes associated with the role of FA in PF. Differential genes in normal and pulmonary fibrosis patients with the GSE2052 dataset were analyzed in the GEO database. The levels of CTGF, α-SMA, MMP-8 in lung and TNF-α in bronchoalveolar lavage fluid (BALF) were detected by ELISA. The levels of HYP in lungs were detected by digestion. The mRNA and protein levels of MMP-7, E-cadherin, CD31, α-SMA, TGF-β1, IL-6, β-catenin, ZO-1, PTPRB, E-cadherin, and vimentin in lungs were detected by RT-qPCR and Western blot. The expression of CD31, α-SMA, TGF-β1 and ZO-1 were detected by immunofluorescence. TGF-β1-stimulated HFL1 cells and human umbilical vein endothelial cells (HUVECs) were used in an attempt to explore the possible role of protein tyrosine phosphatase receptor type B (PTPRB) involved in FA-induced improvement of PF.

RESULTS

The results showed that FA could improve the survival rate and body weight of PF mice. FA could alleviate the symptoms of alveolar wall thickening, inflammatory cell infiltration, blue collagen fiber deposition, collagen fiber type Ⅰ and type Ⅲ in mice with PF. In addition, FA could reduce the levels of HYP, CTGF, α-SMA, TGF-β1, TNF-α, β-catenin and MMP8, and regulate the expression levels of CD31, ZO-1, PTPRB and E-cadherin in lung of mice with PF, inhibiting endothelial-to-mesenchymal transition (EndMT) and fibroblasts proliferation. In the GSE2052 dataset, the expression level of PTPRB is reduced in lung tissue from PF patients, and results from transcriptome sequencing indicate that PTPRB expression is also reduced in PF mice. In addition, the effect of FA on TGF-β1-induced HFL1 or HUVECs cells could be attenuated by the inhibitor of PTPRB, suggesting that the effect of FA on PF is related to PTPRB.

CONCLUSION

This study demonstrated that FA could ameliorate PF by inhibiting lung fibroblast proliferation and EndMT, and that PTPRB might be a target of FA to ameliorate PF, which provided evidence to support FA as a candidate phytochemical for PF.

Exploring the preventive effects of Jie Geng Tang on pulmonary fibrosis induced in vitro and in vivo: a network pharmacology approach

Pulmonary fibrosis is a debilitating lung disease marked by excessive fibrotic tissue accumulation, which significantly impairs respiratory function. Given the limitations of current therapies, there is an increasing interest in exploring traditional herbal formulations like Jie Geng Tang (JGT) for treatment. This study examines the potential of JGT and its bioactive component, quercetin, in reversing bleomycin (BLM)-induced pulmonary fibrosis in mice. We employed a BLM-induced MLE-12 cell damage model for in vitro studies and a bleomycin-induced fibrosis model in C57BL/6 mice for in vivo experiments. In vitro assessments showed that JGT significantly enhanced cell viability and reduced apoptosis in MLE-12 cells treated with BLM. These findings underscore JGT's potential for cytoprotection against fibrotic agents. In vivo, JGT was effective in modulating the expression of E-cadherin and vimentin, key markers of the epithelial-mesenchymal transition (EMT) pathway, indicating its role in mitigating EMT-associated fibrotic changes in lung tissue. Quercetin, identified through network pharmacology analysis as a potential key bioactive component of JGT, was highlighted for its role in the regulatory mechanisms underlying fibrosis progression, particularly through the modulation of the IL-17 pathway and Il6 expression. By targeting inflammatory pathways and key processes like EMT, JGT and quercetin offer a potent alternative to conventional therapies, meriting further clinical exploration to harness their full therapeutic potential in fibrotic diseases.

Prenylated Flavonoids in Sophora flavescens: A Systematic Review of Their Phytochemistry and Pharmacology

Sophora flavescens has been widely used in traditional Chinese medicine for over 1700 years. This plant is known for its heat-clearing, damp-drying, insecticidal, and diuretic properties. Phytochemical research has identified prenylated flavonoids as a unique class of bioactive compounds in S. flavescens. Recent pharmacological studies reveal that the prenylated flavonoids from S. flavescens (PFS) exhibit potent antitumor, anti-inflammatory, and glycolipid metabolism-regulating activities, offering significant therapeutic benefits for various diseases. However, the pharmacokinetics and toxicological profiles of PFS have not been systematically studied. Despite the diverse biological effects of prenylated flavonoid compounds against similar diseases, their structure-activity relationship is not yet fully understood. This review aims to summarize the latest findings regarding the chemical composition, drug metabolism, pharmacological properties, toxicity, and structure-activity relationship of prenylated flavonoids from S. flavescens. It seeks to highlight their potential for clinical use and suggest directions for future related studies.

Therapeutic effects of flavonoids on pulmonary fibrosis: A preclinical meta-analysis

BACKGROUND

The efficacy of flavonoid supplementation in animal models of pulmonary fibrosis has been demonstrated.

PURPOSE

We conducted a systematic review and meta-analysis to evaluate the efficacy and underlying mechanisms of flavonoids in animal models of bleomycin-induced pulmonary fibrosis.

STUDY DESIGN

Relevant studies (n = 45) were identified from English- and Chinese-language databases from the inception of the database until October 2023.

METHODS

Methodological quality was evaluated using the SYRCLE risk of bias tool. Statistical analyses were conducted using RevMan 5.3 and Stata 17.0. Lung inflammation and fibrosis score were the primary outcome indicators.

RESULTS

Flavonoids can alleviate pathological changes in the lungs. The beneficial effects of flavonoids on pulmonary fibrosis likely relate to their inhibition of inflammatory responses, restoration of oxidative and antioxidant homeostasis, and regulation of fibroblast proliferation, migration, and activation by transforming growth factor β1/mothers against the decapentaplegic homologue/AMP-activated protein kinase (TGF-β1/Smad3/AMPK), inhibitor kappa B alpha/nuclear factor-kappa B (IκBα/NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, interleukin 6/signal transducer/activator of transcription 3 (IL6/STAT3), and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathways.

CONCLUSION

Flavonoids are potential candidate compounds for the prevention and treatment of pulmonary fibrosis. However, extensive preclinical research is necessary to confirm the antifibrotic properties of natural flavonoids.

Amifostine ameliorates bleomycin-induced murine pulmonary fibrosis via NAD+/SIRT1/AMPK pathway-mediated effects on mitochondrial function and cellular metabolism

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a devastating chronic lung disease characterized by irreversible scarring of the lung parenchyma. Despite various interventions aimed at mitigating several different molecular aspects of the disease, only two drugs with limited clinical efficacy have so far been approved for IPF therapy.

OBJECTIVE

We investigated the therapeutic efficacy of amifostine, a detoxifying drug clinically used for radiation-caused cytotoxicity, in bleomycin-induced murine pulmonary fibrosis.

METHODS

C57BL6/J mice were intratracheally instilled with 3 U/kg of bleomycin. Three doses of amifostine (WR-2721, 200 mg/kg) were administered intraperitoneally on days 1, 3, and 5 after the bleomycin challenge. Bronchoalveolar lavage fluid (BALF) was collected on day 7 and day 21 for the assessment of lung inflammation, metabolites, and fibrotic injury. Human fibroblasts were treated in vitro with transforming growth factor beta 1 (TGF-β1), followed by amifostine (WR-1065, 1-4 µg/mL) treatment. The effects of TGF-β1 and amifostine on the mitochondrial production of reactive oxygen species (ROS) were assessed by live cell imaging of MitoSOX. Cellular metabolism was assessed by the extracellular acidification rate (ECAR), the oxygen consumption rate (OCR), and the concentrations of various energy-related metabolites as measured by mass spectrum (MS). Western blot analysis was performed to investigate the effect of amifostine on sirtuin 1 (SIRT1) and adenosine monophosphate activated kinase (AMPK).

RESULTS

Three doses of amifostine significantly attenuated lung inflammation and pulmonary fibrosis. Pretreatment and post-treatment of human fibroblast cells with amifostine blocked TGF-β1-induced mitochondrial ROS production and mitochondrial dysfunction in human fibroblast cells. Further, treatment of fibroblasts with TGF-β1 shifted energy metabolism away from mitochondrial oxidative phosphorylation (OXPHOS) and towards glycolysis, as observed by an altered metabolite profile including a decreased ratio of NAD + /NADH and increased lactate concentration. Treatment with amifostine significantly restored energy metabolism and activated SIRT1, which in turn activated AMPK. The activation of AMPK was required to mediate the effects of amifostine on mitochondrial homeostasis and pulmonary fibrosis. This study provides evidence that repurposing of the clinically used drug amifostine may have therapeutic applications for IPF treatment.

CONCLUSION

Amifostine inhibits bleomycin-induced pulmonary fibrosis by restoring mitochondrial function and cellular metabolism.

Daphnetin Alleviates Bleomycin-Induced Pulmonary Fibrosis through Inhibition of Epithelial-to-Mesenchymal Transition and IL-17A

Idiopathic pulmonary fibrosis (IPF) is a chronic and refractory interstitial lung disease. Although there is no cure for IPF, the development of drugs with improved efficacy in the treatment of IPF is required. Daphnetin, a natural coumarin derivative, has immunosuppressive, anti-inflammatory, and antioxidant activities. However, its antifibrotic effects have not yet been elucidated. In this study, we investigated the antifibrotic effects of daphnetin on pulmonary fibrosis and the associated molecular mechanism. We examined the effects of daphnetin on splenocytes cultured in Th17 conditions, lung epithelial cells, and a mouse model of bleomycin (BLM)-induced pulmonary fibrosis. We identified that daphnetin inhibited IL-17A production in developing Th17 cells. We also found that daphnetin suppressed epithelial-to-mesenchymal transition (EMT) in TGF-β-treated BEAS2B cells through the regulation of AKT phosphorylation. In BLM-treated mice, the oral administration of daphnetin attenuated lung histopathology and improved lung mechanical functions. Our findings clearly demonstrated that daphnetin inhibited IL-17A and EMT both in vitro and in vivo, thereby protecting against BLM-induced pulmonary fibrosis. Taken together, these results suggest that daphnetin has potent therapeutic effects on lung fibrosis by modulating both Th17 differentiation and the TGF-β signaling pathway, and we thus expect daphnetin to be a drug candidate for the treatment of IPF.

C5a/C5aR1 axis as a key driver promotes epithelial-to-mesenchymal transition in airway epithelial cells in silica nanoparticles-induced pulmonary fibrosis

Previous studies have shown that silica nanoparticles (SiNPs) exposure can affect the respiratory, cardiovascular, reproductive and other systems, with the lung being the primary target organ for the direct effect, causing damage with a central feature of pulmonary inflammation and fibrosis. However, the underlying mechanisms of pulmonary fibrosis due to SiNPs are not fully understood. The aim of the study was to investigate the role of complement anaphylatoxin C5a in SiNPs-induced pulmonary fibrosis. A mouse model of SiNPs-induced pulmonary fibrosis was established, and pulmonary fibrosis-related indicators, epithelial-to-mesenchymal transition (EMT), C5a/C5aR1 and high mobility group protein B1 (HMGB1) proteins were measured. An in vitro study using the human lung epithelial cell line BEAS-2B investigated whether C5a leads to epithelial-to-mesenchymal trans-differentiation. In vivo studies revealed that SiNPs-induced pulmonary fibrosis mainly manifested as EMT trans-differentiation in airway epithelial cells, which subsequently led to excessive deposition of extracellular matrix (ECM). Furthermore, we found that C5a and C5aR1 proteins were also increased in SiNPs-induced pulmonary fibrosis tissue. In vitro studies also showed that C5a directly activated HMGB1/RAGE signaling and induced EMT in BEAS-2B cells. Finally, treatment of SiNPs-exposed mice with the C5aR1 inhibitor PMX205 effectively reduced C5aR1 levels and inhibited the activation of HMGB1/RAGE signaling and the expression of EMT-related proteins, culminating in a significant alleviation of pulmonary fibrosis. Taken together, our results suggest that C5a/C5aR1 is the main signaling pathway for SiNPs-induced pulmonary fibrosis, which induces EMT in airway epithelial cells via the HMGB1/RAGE axis.

PM2.5 triggers autophagic degradation of Caveolin-1 via endoplasmic reticulum stress (ERS) to enhance the TGF-β1/Smad3 axis promoting pulmonary fibrosis

Air pollution is highly associated with respiratory diseases. However, the influence and mechanism of particulate matter with aerodynamic equal to or less than 2.5 μm (PM2.5) in lung homeostasis remain unclear. Herein, we demonstrated the induction of pulmonary fibrosis (PF) by PM2.5 exposure. The animal model showed that PM2.5 exposure could activate the oxidative stress and inflammation response, promoting epithelial-mesenchymal transition and accumulation of collagen, high expression of pro-fibrotic factors, and pathological characteristics of fibrosis. The proteomic analysis indicated that PM2.5 exposure decreased the expression of caveolin-1 (Cav-1), and many differential proteins were enriched in the TGF-β1/Smad, endoplasmic reticulum stress (ERS) and autophagy pathways. Combining in vivo and in vitro experiments, it was found that PM2.5 exposure could reduce Cav-1 protein levels and activate TGF-β1/Smad3 signaling pathways through ERS and autophagy pathways, thereby inducing cell apoptosis and promoting pulmonary fibrosis. However, inhibiting ERS could alleviate the occurrence of autophagy, and blocking the autophagy system could increase the level of Cav-1 protein and inhibit TGF- β 1/Smad3 signaling pathway to improve pulmonary fibrosis. Therefore, we demonstrated that the exposure of PM2.5 could enhance the ERS induced-autophagy-mediated Cav-1 degradation, thus activating the TGF-β1/Smad3 axis to promote pneumonocytes apoptosis and overproduction of extracellular matrix (ECM), finally aggravating PF. Moreover, our findings revealed that intermittent exposure to high doses of PM2.5 was more toxic than continuous exposure to low dose.

Circulating inflammatory cytokines and risk of idiopathic pulmonary fibrosis: a Mendelian randomization study

BACKGROUND

The previous epidemiological and experimental evidence has implied the linkage between chronic inflammation to idiopathic pulmonary fibrosis (IPF). However, it was still unclear whether there were casual associations between circulating inflammatory cytokines and IPF development. The objective of present study was to examine whether altered genetically predicted concentration of circulating cytokines were associated with IPF development using a two-sample Mendelian randomization (MR) analysis.

MATERIALS AND METHODS

The causal effects of 23 circulating inflammatory cytokines were evaluated on IPF using MR analysis. The primary approach of MR analysis was the inverse variance-weighted (IVW) method. The sensitivity analyses were conducted by simple median, weighted median, penalized weighted median and MR-Egger regression methods.

RESULTS

The present MR study found suggestive evidence that a higher circulating IL-14 level was associated with an increased risk of IPF (random effects IVW method: odds ratio: 1.001, 95% confidence interval: 1.000-1.001, P = 0.026). The sensitivity analysis yielded directionally similar results for IL-14. There was no significant association found between other circulating inflammatory cytokines and IPF.

CONCLUSION

The high level of IL14 predicted by genes had a casual relationship with the increased risk of IPF. This finding provided epidemiological evidence for drug therapy targeting inflammatory factors in the prevention and treatment of IPF. It's warranted further exploration to validate the clinical significance of IL14 associated with developmental risk of IPF.

Tangeretin attenuates bleomycin-induced pulmonary fibrosis by inhibiting epithelial-mesenchymal transition via the PI3K/Akt pathway

Background: Pulmonary fibrosis (PF) is a terminal pathological change in a variety of lung diseases characterized by excessive deposition of extracellular matrix, for which effective treatment is lacking. Tangeretin (Tan), a flavonoid derived from citrus, has been shown to have a wide range of pharmacological effects. This study aimed to investigate the role and potential mechanisms of Tan on pulmonary fibrosis. Methods: A model of pulmonary fibrosis was established by administering bleomycin through tracheal drip, followed by administering Tan or pirfenidone through gavage. HE and Masson staining were employed to assess the extent of pulmonary fibrosis. Subsequently, Western blot, enzyme-linked immunosorbent assay (ELISA), RNA sequencing, and immunohistochemistry techniques were employed to uncover the protective mechanism of Tan in PF mice. Furthermore, A549 cells were stimulated with TGF-β1 to induce epithelial-mesenchymal transition (EMT) and demonstrate the effectiveness of Tan in mitigating PF. Results: Tan significantly ameliorated bleomycin-induced pulmonary fibrosis, improved fibrotic pathological changes, and collagen deposition in the lungs, and reduced lung inflammation and oxidative stress. The KEGG pathway enrichment analysis revealed a higher number of enriched genes in the PI3K/Akt pathway. Additionally, Tan can inhibit the EMT process related to pulmonary fibrosis. Conclusion: Taken together, the above research results indicate that Tan suppresses inflammation, oxidative stress, and EMT in BLM-induced pulmonary fibrosis via the PI3K/Akt pathway and is a potential agent for the treatment of pulmonary fibrosis.

Molecular mechanisms of COVID-19-induced pulmonary fibrosis and epithelial-mesenchymal transition

As the outbreak of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first broke out in Hubei Province, China, at the end of 2019. It has brought great challenges and harms to global public health. SARS-CoV-2 mainly affects the lungs and is mainly manifested as pulmonary disease. However, one of the biggest crises arises from the emergence of COVID-19-induced fibrosis. At present, there are still many questions about how COVID-19 induced pulmonary fibrosis (PF) occurs and how to treat and regulate its long-term effects. In addition, as an important process of fibrosis, the effect of COVID-19 on epithelial-mesenchymal transition (EMT) may be an important factor driving PF. This review summarizes the main pathogenesis and treatment mechanisms of COVID-19 related to PF. Starting with the basic mechanisms of PF, such as EMT, transforming growth factor-β (TGF-β), fibroblasts and myofibroblasts, inflammation, macrophages, innate lymphoid cells, matrix metalloproteinases and tissue inhibitors of metalloproteinases, hedgehog pathway as well as Notch signaling. Further, we highlight the importance of COVID-19-induced EMT in the process of PF and provide an overview of the related molecular mechanisms, which will facilitate future research to propose new clinical therapeutic solutions for the treatment of COVID-19-induced PF.

Niclosamide Attenuates Inflammation-Associated Profibrotic Responses in Human Subepithelial Lung Myofibroblasts

Niclosamide is a commonly used helminthicidic drug for the treatment of human parasitosis by helminths. Recently, efforts have been focusing on repurposing this drug for the treatment of other diseases, such as idiopathic pulmonary fibrosis. Subepithelial lung myofibroblasts (SELMs) isolated from tissue biopsies of patients undergoing surgery for lung cancer were stimulated with TNF-α (50 ng/mL), IL-1α (5 ng/mL), added alone or in combination, and TGF-β₁ (5 ng/mL). After treatment with niclosamide at 30 nM and 100 nM concentrations, expression of collagen type I, collagen type III, and fibronectin was studied by total RNA isolation and qRT-PCR and protein collagen secretion with the use of Sircol collagen assay. The migration of SELMs was assessed by a wound-healing assay. Niclosamide had no effect on baseline SELM fibrotic factor expression. When stimulated with TGF-β₁, IL-1α, and/or TNF-α, SELM expression of collagen type I, type III, and fibronectin were upregulated, as was the secretion of total collagen in the culture medium. Treatment with niclosamide attenuated the effects of cytokine stimulation leading to a notable decrease in the mRNA expression of collagen type I, type III, and fibronectin in a concentration-dependent manner. SELM collagen secretion was also reduced by niclosamide at 100 nM concentration when examined at the protein level. Migration of both TGF-β₁ stimulated and unstimulated SELMs was also inhibited by niclosamide. In this study, we highlight the anti-fibrotic properties of niclosamide on SELMs under stimulation with pro-fibrotic and pro-inflammatory cytokines, thus proposing this compound as a possible new therapeutic agent against lung fibrosis.

Phytochemistry and pharmacology of natural prenylated flavonoids

Prenylated flavonoids are a special kind of flavonoid derivative possessing one or more prenyl groups in the parent nucleus of the flavonoid. The presence of the prenyl side chain enriched the structural diversity of flavonoids and increased their bioactivity and bioavailability. Prenylated flavonoids show a wide range of biological activities, such as anti-cancer, anti-inflammatory, neuroprotective, anti-diabetic, anti-obesity, cardioprotective effects, and anti-osteoclastogenic activities. In recent years, many compounds with significant activity have been discovered with the continuous excavation of the medicinal value of prenylated flavonoids, and have attracted the extensive attention of pharmacologists. This review summarizes recent progress on research into natural active prenylated flavonoids to promote new discoveries of their medicinal value.

Immune Mechanisms of Pulmonary Fibrosis with Bleomycin

Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial-mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.

Berberine regulates pulmonary inflammatory microenvironment and decreases collagen deposition in response to bleomycin-induced pulmonary fibrosis in mice

The purpose of this study was to explore the protective effect and potential mechanism of berberine on bleomycin (BLM)-induced fibrosis after lung injury in conjunction with network pharmacology. Berberine and pulmonary fibrosis prediction targets were collected for Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and so forth. A single intranasal dose of BLM (2.5 mg/kg) was administered to establish a model of fibrosis after lung injury, and berberine (50 mg/kg) was administered intraperitoneally daily for treatment. Network pharmacology results suggested that the mitogen-activated protein kinase (MAPK) signalling pathway may be a potential mechanism of berberine in delaying pulmonary fibrosis. The results of animal experiments showed that compared with the BLM group, after 14 days of berberine treatment, lung inflammatory cell aggregation was reduced and the expression levels of tumour necrosis factor-α (TNF-α), interleukin (IL)-8 and IL-6 were down-regulated in mice (p < 0.05); after 42 days of berberine treatment, the expression levels of transforming growth factor (TGF)-β1, platelet-derived growth factor-AB (PDGF-AB), hydroxyproline (HYP) and α-smooth muscle actin (α-SMA) were significantly down-regulated (p < 0.05), and the expression levels of total p38 MAPKα and p38 MAPKα (pT180/Y182) were down-regulated also (p < 0.05), inhibited collagen production and deposition, and increased the survival rate of mice to 70%. In conclusion, berberine attenuated inflammation mice, inhibited collagen production and showed some anti-pulmonary fibrosis potential in the MAPK signalling pathway.

Theophylline Attenuates BLM-Induced Pulmonary Fibrosis by Inhibiting Th17 Differentiation

Idiopathic pulmonary fibrosis (IPF) is a chronic and refractory interstitial lung disease. Although there are two approved drugs for IPF, they were not able to completely cure the disease. Therefore, the development of new drugs is required for the effective treatment of IPF. In this study, we investigated the effect of theophylline, which has long been used for the treatment of asthma, on pulmonary fibrosis. The administration of theophylline attenuated the fibrotic changes of lung tissues and improved mechanical pulmonary functions in bleomycin (BLM)-induced pulmonary fibrosis. Theophylline treatment suppressed IL-17 production through inhibiting cytokines controlling Th17 differentiation; TGF-β, IL-6, IL-1β, and IL-23. The inhibition of IL-6 and IL-1β by theophylline is mediated by suppressing BLM-induced ROS production and NF-κB activation in epithelial cells. We further demonstrated that theophylline inhibited TGF-β-induced epithelial-to-mesenchymal transition in epithelial cells through suppressing the phosphorylation of Smad2/3 and AKT. The inhibitory effects of theophylline on the phosphorylation of Smad2/3 and AKT were recapitulated in BLM-treated lung tissues. Taken together, these results demonstrated that theophylline prevents pulmonary fibrosis by inhibiting Th17 differentiation and TGF-β signaling.

Kurarinone alleviates hemin-induced neuroinflammation and microglia-mediated neurotoxicity by shifting microglial M1/M2 polarization via regulating the IGF1/PI3K/Akt signaling

Cerebral hemorrhage is a fatal disease that causes severe damage to local nerve function. The purpose of this research is to analyze the effect of kurarinone on hemin-induced neuroinflammation and neurotoxicity. In our study, according to the results of bioinformatics analysis, we hypothesized that kurarinone might modulate cerebral hemorrhage advancement via the insulin-like growth factor 1/phosphoinositide 3-kinase/protein kinase B (IGF1/PI3K/Akt) signaling. Kurarinone promoted M2 microglia polarization, and curbed M1 polarization and inflammation in human microglial cells (HMC3) cells with hemin treatment. Besides, kurarinone upregulated IGF1 expression and activated the PI3K/Akt signaling pathway in hemin-treated HMC3 cells. In addition, downregulation of IGF1 or inhibition of the PI3K/Akt signaling weakened the effects of kurarinone on microglia polarization and inflammation in HMC3 cells with hemin treatment. Kurarinone alleviated apoptosis and oxidative damage of SH-SY5Y cells co-cultured with hemin-treated HMC3 cells. In conclusion, kurarinone lessened hemin-induced neuroinflammation and microglia-mediated neurotoxicity by regulating microglial polarization through modulating the IGF1/PI3K/Akt signaling. These results delivered a new prospective therapeutic drug for the treatment of cerebral hemorrhage.