IL-27 attenuates the TGF-β1-induced proliferation, differentiation and collagen synthesis in lung fibroblasts

An updated advancement of bifunctional IL-27 in inflammatory autoimmune diseases

Interleukin-27 (IL-27) is a member of the IL-12 family. The gene encoding IL-27 is located at chromosome 16p11. IL-27 is considered as a heterodimeric cytokine, which consists of Epstein-Barr virus (EBV)-induced gene 3 (Ebi3) and IL-27p28. Based on the function of IL-27, it binds to receptor IL-27rα or gp130 and then regulates downstream cascade. To date, findings show that the expression of IL-27 is abnormal in different inflammatory autoimmune diseases (including systemic lupus erythematosus, rheumatoid arthritis, Sjogren syndrome, Behcet's disease, inflammatory bowel disease, multiple sclerosis, systemic sclerosis, type 1 diabetes, Vogt-Koyanagi-Harada, and ankylosing spondylitis). Moreover, in vivo and in vitro studies demonstrated that IL-27 is significantly in3volved in the development of these diseases by regulating innate and adaptive immune responses, playing either an anti-inflammatory or a pro-inflammatory role. In this review, we comprehensively summarized information about IL-27 and autoimmunity based on available evidence. It is hoped that targeting IL-27 will hold great promise in the treatment of inflammatory autoimmune disorders in the future.

Medicine Targeting Epithelial-Mesenchymal Transition to Treat Airway Remodeling and Pulmonary Fibrosis Progression

Objective. Dysregulation of epithelial-mesenchymal transition (EMT) in the airway epithelium is associated with airway remodeling and the progression of pulmonary fibrosis. Many treatments have been shown to inhibit airway remodeling and pulmonary fibrosis progression in asthma and chronic obstructive pulmonary disease (COPD) by regulating EMT and have few side effects. This review aimed to describe the development of airway remodeling through the EMT pathway, as well as the potential therapeutic targets in these pathways. Furthermore, this study aimed to review the current research on drugs to treat airway remodeling and their effects on the EMT pathway. Findings. The dysregulation of EMT was associated with airway remodeling in various respiratory diseases. The cytokines released during inflammation may induce EMT and subsequent airway remodeling. Various drugs, including herbal formulations, specific herbal compounds, cytokines, amino acid or protein inhibitors, microRNAs, and vitamins, may suppress airway remodeling by inhibiting EMT-related pathways.

Externalized histones fuel pulmonary fibrosis via a platelet-macrophage circuit of TGFβ1 and IL-27

Externalized histones erupt from the nucleus as extracellular traps, are associated with several acute and chronic lung disorders, but their implications in the molecular pathogenesis of interstitial lung disease are incompletely defined. To investigate the role and molecular mechanisms of externalized histones within the immunologic networks of pulmonary fibrosis, we studied externalized histones in human and animal bronchoalveolar lavage (BAL) samples of lung fibrosis. Neutralizing anti-histone antibodies were administered in bleomycin-induced fibrosis of C57BL/6 J mice, and subsequent studies used conditional/constitutive knockout mouse strains for TGFβ and IL-27 signaling along with isolated platelets and cultured macrophages. We found that externalized histones (citH3) were significantly (P < 0.01) increased in cell-free BAL fluids of patients with idiopathic pulmonary fibrosis (IPF; n = 29) as compared to healthy controls (n = 10). The pulmonary sources of externalized histones were Ly6G+CD11b+ neutrophils and nonhematopoietic cells after bleomycin in mice. Neutralizing monoclonal anti-histone H2A/H4 antibodies reduced the pulmonary collagen accumulation and hydroxyproline concentration. Histones activated platelets to release TGFβ1, which signaled through the TGFbRI/TGFbRII receptor complex on LysM+ cells to antagonize macrophage-derived IL-27 production. TGFβ1 evoked multiple downstream mechanisms in macrophages, including p38 MAPK, tristetraprolin, IL-10, and binding of SMAD3 to the IL-27 promotor regions. IL-27RA-deficient mice displayed more severe collagen depositions suggesting that intact IL-27 signaling limits fibrosis. In conclusion, externalized histones inactivate a safety switch of antifibrotic, macrophage-derived IL-27 by boosting platelet-derived TGFβ1. Externalized histones are accessible to neutralizing antibodies for improving the severity of experimental pulmonary fibrosis.

IL-27 promotes cardiac fibroblast activation and aggravates cardiac remodeling post myocardial infarction

Excessive and chronic inflammation post myocardial infarction (MI) causes cardiac fibrosis and progressive ventricular remodeling, which leads to heart failure. We previously found high levels of IL-27 in the heart and serum until day 14 in murine cardiac ischemia‒reperfusion injury models. However, whether IL-27 is involved in chronic inflammation-mediated ventricular remodeling remains unclear. In the present study, we found that MI triggered high IL-27 expression in murine cardiac macrophages. The increased expression of IL-27 in serum is correlated with cardiac dysfunction and aggravated fibrosis after MI. Furthermore, the addition of IL-27 significantly activated the JAK/STAT signaling pathway in cardiac fibroblasts (CFs). Meanwhile, IL-27 treatment promoted the proliferation, migration and extracellular matrix (ECM) production of CFs induced by angiotensin II (Ang II). Collectively, high levels of IL-27 mainly produced by cardiac macrophages post MI contribute to the activation of CFs and aggravate cardiac fibrosis.

IL-27 induces autophagy through regulation of the DNMT1/lncRNA MEG3/ERK/p38 axis to reduce pulmonary fibrosis

PURPOSE

Previous studies have shown that interleukin-27 (IL-27) can reduce bleomycin (BLM)-induced pulmonary fibrosis (PF). However, the underlying mechanism by which IL-27 attenuates PF is not fully clear.

METHODS

In this research, we used BLM to construct a PF mouse model, and MRC-5 cells stimulated by transforming growth factor-β1 (TGF-β1) were used to construct a PF model in vitro. The lung tissue status was observed by Masson and hematoxylin and eosin (HE) staining. To detect gene expression, RT‒qPCR was used. The protein levels were detected by western blotting and immunofluorescence staining. EdU and ELISA were used to detect cell proliferation viability and hydroxyproline (HYP) content, respectively.

RESULTS

Aberrant IL-27 expression was observed in BLM-induced mouse lung tissues, and the use of IL-27 attenuated mouse lung tissue fibrosis. TGF-β1 induced autophagy inhibition in MRC-5 cells, and IL-27 alleviated MRC-5 cell fibrosis by activating autophagy. The mechanism is inhibition of DNA methyltransferase 1 (DNMT1)-mediated lncRNA MEG3 methylation and ERK/p38 signaling pathway activation. Overexpression of DNMT1, knockdown of lncRNA MEG3, autophagy inhibitor or ERK/p38 signaling pathway inhibitors reversed the positive effect of IL-27 in a lung fibrosis model in vitro.

CONCLUSION

In conclusion, our study shows that IL-27 upregulates MEG3 expression through inhibition of DNMT1-mediated lncRNA MEG3 promoter methylation, which in turn inhibits ERK/p38 signaling pathway-induced autophagy and attenuates BLM-induced PF, providing a contribution to the elucidation of the potential mechanisms by which IL-27 attenuates PF.

Noncanonical JAK1/STAT3 interactions with TGF-β modulate myofibroblast transdifferentiation and fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with limited survival. Janus kinases (JAKs), tyrosine kinases that transduce cytokine-mediated signals, are known to be involved, but their specific roles in lung fibrosis are not well defined. In this study, the interactions between JAK1/signal transducers and activators of transcription (STAT)3 signaling and transforming growth factor-beta (TGF-β)-induced fibroblast responses were investigated using both pharmacological and siRNA approaches in human normal and IPF-derived lung fibroblasts. We found that JAK1 directly interacts with the TGF-β receptor I subunit (TβRI), and silencing JAK1 promotes myofibroblast transdifferentiation. However, the suppression of JAK1 signaling in vitro and in vivo using an inhibitor (upadacitinib) did not alter lung fibroblast activation or fibrosis development. STAT3 was constitutively active in cultured primary lung fibroblasts; this STAT3 activation required JAK1 and repressed myofibroblast transdifferentiation. Loss of phosphorylated STAT3 following transcriptional JAK1 silencing promoted myofibroblast transdifferentiation. In contrast, transcriptional silencing of unphosphorylated STAT3 suppressed TGF-β signaling, decreased SMAD3 activation, and reduced myofibroblast transdifferentiation and ECM production. Taken together, these observations support a role for JAK1/STAT3 as a direct regulator of TGF-β signaling in lung fibroblasts. Modulation of JAK1/STAT3 signaling in lung fibroblasts represents a noncanonical approach to regulating TGF-β-induced fibrosis and suggests the potential for a novel approach to treat pulmonary fibrosis.

IL-27 regulates autophagy in rheumatoid arthritis fibroblast-like synoviocytes via STAT3 signaling

Rheumatoid arthritis (RA) is a highly prevalent autoimmune condition associated with pronounced synovial inflammation. The majority of RA patients required long-term treatment to control disease progression, thus imposing a significant financial burden on affected individuals. The development of RA is critically influenced by fibroblast-like synoviocytes (FLSs) within the synovial lining. IL-27 is an IL-6/IL-12 family cytokine that has recently been shown to play varied pro-inflammatory or protective roles in particular autoimmune diseases. However, the effects of IL-27 on FLSs in the context of RA have yet to be clarified and warrant further research. This study was developed to evaluate the impact of IL-27 treatment on apoptotic and autophagic activity in RA-associated FLSs, with a particular focus on the role of the STAT3 pathway in this regulatory context. Through these experiments, we found that IL-27 was able to suppress FLS proliferation and autophagic activity, with a high dose of this cytokine (100 ng/mL) markedly suppressing autophagy while simultaneously inducing some level of cellular apoptosis. The STAT3 inhibitor STA21 was found to reverse the IL-27-mediated suppression of autophagic activity in these RA-associated FLSs. Imbalanced cellular proliferation and apoptosis is of critical importance in the context of RA progression, and we found that IL-27 was able to regulate such imbalance and to enhance the apoptotic activity of RA FLSs by inhibiting rapamycin-activated autophagy. Together, these results indicate that IL-27 can regulate autophagic activity within RA-associated FLSs via the STAT3 signaling pathway, leading to inhibition of cellular proliferation.

Inhaled siRNA nanoparticles targeting IL11 inhibit lung fibrosis and improve pulmonary function post-bleomycin challenge

Interleukin-11 (IL-11) is a profibrotic cytokine essential for the differentiation of fibroblasts into collagen-secreting, actin alpha 2, smooth muscle-positive (ACTA2⁺) myofibroblasts, driving processes underlying the pathogenesis of idiopathic pulmonary fibrosis (IPF). Here, we developed an inhalable and mucus-penetrative nanoparticle (NP) system incorporating siRNA against IL11 (siIL11@PPGC NPs) and investigated therapeutic potential for the treatment of IPF. NPs are formulated through self-assembly of a biodegradable PLGA-PEG diblock copolymer and a self-created cationic lipid-like molecule G0-C14 to enable efficient transmucosal delivery of siIL11. Noninvasive aerosol inhalation hindered fibroblast differentiation and reduced ECM deposition via inhibition of ERK and SMAD2. Furthermore, siIL11@PPGC NPs significantly diminished fibrosis development and improved pulmonary function in a mouse model of bleomycin-induced pulmonary fibrosis without inducing systemic toxicity. This work presents a versatile NP platform for the locally inhaled delivery of siRNA therapeutics and exhibits promising clinical potential in the treatment of numerous respiratory diseases, including IPF.

Salvianolic acid B regulates collagen synthesis: Indirect influence on human dermal fibroblasts through the microvascular endothelial cell pathway

BACKGROUND

Salvianolic acid B (SAB) is one of the main active ingredients of Salvia Miltiorrhiza. It has significant skin anti-aging, whitening, and sun protection properties.

AIMS

The study aimed at studying the mechanism underlying the effect of salvianolic acid Bon collagen synthesis, which has good anti-aging efficacy and modulates microcirculation.

METHODS

This study employed available public databases, bioinformatics methodologies, and the inverse docking approach to explore the effectiveness of SAB in the regulating collagen synthesis, and then used an human dermal fibroblast (HDF)- Human dermal microvascular endothelial cell (HDMEC) in vitro model to validate the predicted mechanism of SAB in influencing collagen synthesis.

RESULTS

The results showed that NO production in SAB-treated HDMEC-conditioned medium was increased compared to that in control media, and the same tendency was also observed for growth factor production. SAB also upregulated HDMEC cellular eNOS and VEGF. When SAB-treated HDMEC conditioned medium was transferred to HDFs, the expression of collagen I, collagen III, and elastin in HDFs was upregulated and MMP-1 was downregulated.

CONCLUSIONS

The results show that SAB regulates collagen through the HDMEC-HDF pathway. Furthermore, the mechanisms might be closely related to the microcirculation factors NO and VEGF.

The Improvement Effect of Sodium Ferulate on the Formation of Pulmonary Fibrosis in Silicosis Mice Through the Neutrophil Alkaline Phosphatase 3 (NALP3)/Transforming Growth Factor-β1 (TGF-β1)/α-Smooth Muscle Actin (α-SMA) Pathway

Background

Pneumoconiosis is a chronic progressive fibrotic interstitial pneumonia for which the pathogenesis and treatment remain unclear. Previous studies showed that sodium ferulate (SF) may have a therapeutic effect, and this study explored the mechanism underlying SF-related improvement.

Material/Methods

In this study, a silicosis mouse model and primary cultured mouse lung fibroblasts were established. Hematoxylin-eosin staining, western blot analysis, quantitative real-time polymerase chain reaction, and Masson staining were used to observe the lung injury, expression of vimentin, and the degree of pulmonary fibrosis. The extracted lung fibroblasts were identified by immunofluorescence. The expression of fibrosis-related genes encoding transforming growth factor-β1 (TGF-β1), neutrophil alkaline phosphatase 3 (NALP3), collagen-1, α-smooth muscle actin (α-SMA), and phosphorylated p38 (p-p38) and p38 proteins were detected by western blot. The effects of SF and the TGF-β pathway agonist SRI-011381 on cell proliferation and the expression of fibrosis-related protein in mouse lung fibroblasts were measured by Cell Counting Kit-8, immunofluorescence, and western blot as needed.

Results

SF reduced the lung lesions in silicosis mice and inhibited the expression of vimentin and fibrosis-related genes, while having no effect on body weight. Vimentin expression was positive in the extracted cells. In vitro experiments showed that SF inhibited the proliferation of lung fibroblasts and the expression of fibrosis-related proteins. In addition, SF partly reversed the opposite regulatory effect of SRI-011381 on lung fibroblasts.

Conclusions

SF inhibited lung injury and fibrosis in silicosis mice through the NALP3/TGF-β1/α-SMA pathway.

trans-Cinnamic acid, but not p-coumaric acid or methyl cinnamate, induces fibroblast migration through PKA- and p38-MAPK signalling pathways

AIM

Hydroxycinnamic acids their derivatives have various pharmacological properties. The hydroxycinnamic acid derivatives, methyl cinnamate, trans-cinnamic, and p-coumaric acids have been the object of study in the treatment of skin wounds. However, it is unclear whether these derivatives exert a direct beneficial effect on fibroblast function. In this study, we evaluated the effects of methyl cinnamate, trans-cinnamic, and p-coumaric acids on fibroblast migration in vitro.

MATERIALS AND METHODS

NIH 3T3 and L929 fibroblast cell lines were exposed to each drug at several concentrations and the effect on cell viability, cell cycle, and extracellular matrix production were assessed by MTT assay, flow cytometry, and immunofluorescence staining, respectively. The effect on cell migration was examined using scratch assay.

RESULTS

The results showed that hydroxycinnamic acid derivatives not affect cell viability, but increase fibroblast migration in the in vitro scratch-wound healing assay. They also induced an increase in S and G2/M phases accompanied by a decrease in the G0/G1 phase of the cell cycle. The cell proliferation inhibitor mitomycin C abolished the effect induced by p-coumaric acid and methyl cinnamate, indicating that only the trans-cinnamic acid stimulated migration. A transwell migration assay confirmed that trans-cinnamic acid-treated fibroblasts exhibited increased migration compared with untreated cells. trans-Cinnamic acid-induced fibroblast migration was decreased by PKA inhibitor and p38-MAPK inhibitor but not by JNK inhibitor. Additionally, trans-cinnamic acid-treated fibroblasts showed an increase in the production of laminin and collagen type I.

CONCLUSION

Our study showed that trans-cinnamic acid improves fibroblast migration and modulates extracellular matrix synthesis, indicating its potential for accelerating the healing process.

Role of interleukins in the pathogenesis of pulmonary fibrosis

Interleukins, a group of cytokines participating in inflammation and immune response, are proved to be involved in the formation and development of pulmonary fibrosis. In this article, we reviewed the relationship between interleukins and pulmonary fibrosis from the clinical, animal, as well as cellular levels, and discussed the underlying mechanisms in vivo and in vitro. Despite the effects of interleukin-targeted treatment on experimental pulmonary fibrosis, clinical applications are lacking and unsatisfactory. We conclude that intervening in one type of interleukins with similar functions in IPF may not be enough to stop the development of fibrosis as it involves a complex network of regulation mechanisms. Intervening interleukins combined with other existing therapy or targeting interleukins affecting multiple cells/with different functions at the same time may be one of the future directions. Furthermore, the intervention time is critical as some interleukins play different roles at different stages. Further elucidation on these aspects would provide new perspectives on both the pathogenesis mechanism, as well as the therapeutic strategy and drug development.

The Effects of Tofacitinib-Mediated Janus Kinase/Signal Transducers and Activators of the Transcription Signal Pathway Inhibition on Collagen Biosynthesis in Hepatic and Skin Fibroblast Cell Culture

Objectives

This study aims to investigate the effects of Janus kinase/signal transducers and activators of the transcription (JAK/STAT) pathway inhibition on collagen biosynthesis in fibroblast cell culture by tofacitinib.

Materials and methods

BJ-CRL-1474® (skin) and BRL3A® (hepatic) fibroblast cell cultures were proliferated in a suitable medium. Tofacitinib was administered to fibroblast cells proliferating in 96-well flasks at concentrations of 25, 50, 100, 200, 400, and 800 nM. Tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase-3 (MMP-3), transforming growth factor beta 1 (TGF-β1), and hydroxyproline levels were measured using the enzyme-linked immunosorbent assay method.

Results

Tofacitinib showed cytotoxic effect on skin and liver cell culture. The cytotoxic effect of tofacitinib started at 100 nM (p<0.05). The highest effect was obtained at 800 nM. The time-dependent cytotoxic effect of tofacitinib was significantly higher at all concentrations after 72 hours than at 24 and 48 hours (p<0.05). The level of TGF-β1 was significantly lower even at a tofacitinib concentration of 25 nM (p<0.05). There were significant decreases in MMP-3, TIMP-1, and hydroxyproline levels after tofacitinib administration (p<0.05).

Conclusion

Tofacitinib inhibited fibroblast cell proliferation in a concentration-dependent manner in a fibroblast cell culture. However, further extensive animal and human studies are necessary to determine the clinical significance of this effect.

PERK-Dependent Activation of the JAK2/STAT3 Pathway Contributes to High Glucose-Induced Extracellular Matrix Deposition in Renal Tubular Epithelial Cells

BACKGROUND

Although the deposition of extracellular matrix (ECM) is critical leading to tubular damage in diabetic kidney disease (DKD), the mechanism still remains unclear. The purpose of this study was to demonstrate a role for protein kinase R-like endoplasmic reticulum kinase (PERK) (a protein located in the endoplasmic reticulum membrane) in this pathologic process.

METHODS

NRK-52E cells were grown in the media containing different concentrations of glucose or thapsigargin for different durations. Cells were subsequently incubated with or without AG490, a selective inhibitor of Janus kinase 2 (JAK2) or GSK2606414 (a selective PERK inhibitor). We evaluated the production of TGF-β1, fibronectin, and collagen I proteins by ELISA. The levels of 78 kD-glucose-regulated protein (GRP78) and PERK, as well as the phosphorylation statues of PERK and JAK2/signal transducer and activator of transcription (STAT3), were determined by western blotting analysis.

RESULTS

We showed that the increased phosphorylation of JAK2 and STAT3 was accompanied by overexpression of TGF-β1 and ECM deposition in high glucose medium. Disruption of the JAK2/STAT3 pathway with AG490 significantly prevents the high glucose-induced increase in TGF-β1, fibronectin, and collagen I. High glucose induced the overproduction of GRP78 and phosphorylation of PERK, which indicated that endoplasmic reticulum stress (ERS) was triggered in NRK-52E cells cultured under high glucose condition. Inhibition of PERK phosphorylation with GSK2606414, however, blocked the effect of JAK2/STAT3 on the production of TGF-β1 and ECM components in NRK-52E cells.

CONCLUSION

Our data indicated that the ECM accumulation induced by high glucose arouse via the PERK-dependent JAK2/STAT3-signaling pathway in renal tubular epithelial cells.

The rationale for targeting the JAK/STAT pathway in scleroderma-associated interstitial lung disease

The etiopathogenesis of systemic sclerosis (SSc)-associated interstitial lung disease (ILD) is still debated and no therapeutic options have proved fully effective to date. The intracellular Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is highly conserved among either immune or nonimmune cells and involved in inflammation and fibrosis. Evidence from preclinical studies shows that the JAK/STAT signaling cascade has a crucial role in the differentiation of autoreactive cells as well as in the extracellular matrix remodeling that occurs in SSc. Therefore, it is likely that the use of oral small molecule JAK-inhibitors, especially if prescribed early, may prevent or slow the progression of SSc-associated ILD, but few clinical studies currently support this hypothesis.

Uvaol Improves the Functioning of Fibroblasts and Endothelial Cells and Accelerates the Healing of Cutaneous Wounds in Mice

Uvaol is a natural pentacyclic triterpene that is widely found in olives and virgin olive oil, exerting various pharmacological properties. However, information remains limited about how it affects fibroblasts and endothelial cells in events associated with wound healing. Here, we report the effect of uvaol in the in vitro and in vivo healing process. We show the positive effects of uvaol on migration of fibroblasts and endothelial cells in the scratch assay. Protein synthesis of fibronectin and laminin (but not collagen type I) was improved in uvaol-treated fibroblasts. In comparison, tube formation by endothelial cells was enhanced after uvaol treatment. Mechanistically, the effects of uvaol on cell migration involved the PKA and p38-MAPK signaling pathway in endothelial cells but not in fibroblasts. Thus, the uvaol-induced migratory response was dependent on the PKA pathway. Finally, topical treatment with uvaol caused wounds to close faster than in the control treatment using experimental cutaneous wounds model in mice. In conclusion, uvaol positively affects the behavior of fibroblasts and endothelial cells, potentially promoting cutaneous healing.

IL‑27 suppresses airway inflammation, hyperresponsiveness and remodeling via the STAT1 and STAT3 pathways in mice with allergic asthma

Type 2 cytokine-associated immunity may be involved in the pathogenesis of allergic asthma. Although interleukin 27 (IL-27) has been reported as an initiator and suppressor of T-helper 1 (Th1) and T-helper 2 (Th2) responses, respectively, its effects on the development of asthma remain unclear. In the present study, mice were induced and challenged with ovalbumin and received subsequent intranasal administration of IL-27. Total and differential cell counts were determined from Wright-Giemsa-stained cytospins, whereas the cytokine levels were detected using ELISA. In addition, the expression levels of signal transducer and activator of transcription (STAT) 1, STAT3, GATA-binding protein-3 (GATA3) and T-bet (T-box transcription factor) were analyzed in T cells by western blot analysis. Their corresponding mRNA expression levels were determined by quantitative PCR. Airway remodeling was assessed by conventional pathological techniques. The results indicated that intranasal administration of IL-27 ameliorated airway inflammation and hyperresponsiveness in an acute model of asthma. Furthermore, IL-27 prevented airway remodeling in a chronic model of asthma. Following administration of IL-27, the mRNA expression levels of STAT1 and T-bet were upregulated, while those of GATA3 were downregulated. Moreover, the phosphorylation levels of STAT1 and STAT3 were increased. Taken together, these findings demonstrated that intranasal administration of IL-27 ameliorated Th2-related allergic lung inflammation and remodeling in mouse models of asthma by repairing both the STAT1 and STAT3 pathways.

CircRNA-012091/PPP1R13B-mediated Lung Fibrotic Response in Silicosis via Endoplasmic Reticulum Stress and Autophagy

Silicosis is a progressive fibrotic disease of lung tissue caused by long-term inhalation of SiO₂. However, relatively few studies of the direct effects of SiO₂ on lung fibroblasts have been performed. PPP1R13B is a major member of the apoptosis-stimulating proteins of the p53 family, but its role in pulmonary fibrosis is unclear. To elucidate the role of PPP1R13B in the pathological process of silicosis, we explored the molecular mechanisms related to PPP1R13B and the functional effects of proliferation and migration of fibroblasts. Through lentivirus transfection, Western blotting, and fluorescent in situ hybridization experiments, we found that SiO₂ downregulated circRNA-012091 (circ-012091) expression in lung fibroblasts and induced upregulation of downstream PPP1R13B. Transfection of L929 cells with PPP1R13B CRISPR NIC plasmid inhibited the upregulation of endoplasmic reticulum stress (ERS) and autophagy-related protein expression in lung fibroblasts treated with SiO₂, and induced decreases in cell proliferation, migration, and viability. Transfection of L929 cells with the PPP1R13B CRISPR ACT plasmid induced increases in cell proliferation, migration, and viability. In addition, the ERS inhibitor salubrinal and the autophagy inhibitor 3-methyladenine inhibited the increased migration of L929 cells transfected with the PPP1R13B CRISPR ACT plasmid. These results suggest that PPP1R13B regulated by circ-012091 promotes the proliferation and migration of lung fibroblasts through ERS and autophagy, and plays a crucial role in the development of pulmonary fibrosis in silicosis.

IL-27 alleviates airway remodeling in a mouse model of asthma via PI3K/Akt pathway

Purpose: Airway remodeling is one of the features of severe asthma. Previous study shows that IL-27 inhibits airway inflammation in asthmatic mice. However, the role of IL-27 on airway remodeling in OVA-induced asthmatic mice and its possible mechanism remain unclear. Methods: We established an ovalbumin (OVA)-induced asthmatic mice model. IL-27 were preventative administered to OVA-induced asthmatic mice. The total cells in Bronchoalveolar lavage fluid (BALF) and Airway hyperresponsiveness (AHR) were measured. The lung tissues were performed by Hematoxylin and eosin (HE) staining to estimate the pathological changes. Masson staining was used to observe the collagen deposition area. The expression of α-smooth muscle actin (α-SMA) and Type I collagen was measured by immunohistochemistry, western blot, and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Additionally, western blot was also used to measure the expression of phosphorylated-Akt (p-Akt) in each group. Results: IL-27 group showed significant inhibitory effect on the α-SMA and Type I collagen. The expression of p-Akt in the tissues of asthma model was increased and inhibited by IL-27. Conclusions: IL-27 can alleviate airway remodeling in OVA-induced asthmatic mice, and the mechanism may relate to PI3K/Akt pathway.

IL-27, IL-30, and IL-35: A Cytokine Triumvirate in Cancer

The role of the immune system in anti-tumor immunity cannot be overstated, as it holds the potential to promote tumor eradication or prevent tumor cell escape. Cytokines are critical to influencing the immune responses and interactions with non-immune cells. Recently, the IL-12 and IL-6 family of cytokines have accumulated newly defined members each with specific immune functions related to various cancers and tumorigenesis. There is a need to better understand how cytokines like IL-27, IL-30, and IL-35 interact with one another, and how a developing tumor can exploit these interactions to enhance immune suppression. Current cytokine-based immunotherapies are associated with cytotoxic side effects which limits the success of treatment. In addition to this toxicity, understanding the complex interactions between immune and cancer cells may be one of the greatest challenges to developing a successful immunotherapy. In this review, we bring forth IL-27, IL-30, and IL-35, “sister cytokines,” along with more recent additions to the IL-12 family, which serve distinct purposes despite sharing structural similarities. We highlight how these cytokines function in the tumor microenvironment by examining their direct effects on cancer cells as well their indirect actions via regulatory functions of immune cells that act to either instigate or inhibit tumor progression. Understanding the context dependent immunomodulatory outcomes of these sister cytokines, as well as their regulation within the tumor microenvironment, may shed light onto novel cancer therapeutic treatments or targets.

Location and dynamic changes of inflammation, fibrosis, and expression levels of related genes in SiO2-induced pulmonary fibrosis in rats in vivo

Silicosis is a serious occupational disease characterized by pulmonary fibrosis, and its mechanism and progression have not been fully elucidated yet. In this study, silicosis models of rat were established by a one-time dusting method, and the rats were sacrificed after 30, 60, and 120 days (herein referred to as the 30, 60, and 120 days groups, respectively). The rats without dust exposure were used as the control. The lungs were removed to observe pathological changes using hematoxylin and eosin and Masson’s trichrome staining and transmission electron microscopy, and the degree of collagen type I and III deposition in the lung was evaluated by enzyme‐linked immunosorbent assay. The levels of malondialdehyde and superoxide dismutase were measured by spectrophotometry, and the expression levels of fibrosis-related genes (transforming growth factor beta 1, type I collagen, type III collagen) were assessed by real-time quantitative polymerase chain reaction. The results suggested that the rats in the model groups exhibited obvious collagen fibrosis and that the severity of the lung injury increased as the time after exposure to SiO₂ increased. There was a significant response to lung inflammation in the model rats, especially in the 30 days group. The degree of lipid peroxidation in bronchoalveolar lavage fluid cells and lung tissues in experiment group rats significantly increased. Among the three fibrosis-related genes, transforming growth factor beta 1was elevated in both bronchoalveolar lavage fluid cells and lung tissues of the experiment group rats, while collagen type I and III were only elevated in lung tissues. Hence, we concluded that as silicosis progressed, inflammation, fibrosis, and the expression of fibrosis-related genes showed different time-dependent changes and that a number of causal relationships existed among them.

Ameliorative effect of ursolic acid on renal fibrosis in adenine-induced chronic kidney disease in rats

Ursolic acid (UA), an ursane-type pentacyclic triterpenoid commonly found in apple peels and holy basil has been shown to possess many beneficial effects. Renal fibrosis is a complication of kidney injury and associated with increased risk of morbidity and mortality. In our previous investigation, a lupane-type pentacyclic triterpenoid, betulinic acid (BA) was found to have protective effect on chronic kidney disease (CKD) and renal fibrosis. This prompted us to explore the therapeutic value of UA, a chemically related compound to BA in CKD. CKD was induced by feeding adenine with the feed at a concentration of 0.75% for 28 days. UA at the dose rate of 30 mg/kg in 0.5% carboxy methyl cellulose (CMC) was administered by oral route, simultaneously with adenine feeding for 28 days. Adenine feeding increased the kidney weight to body weight index, decreased the kidney function due to injury as indicated by increased markers like serum urea, uric acid, creatinine, cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) and initiated the fibrotic response in kidney by increasing the profibrotic proteins viz. transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF), fibronectin and collagen. However, treatment with UA reversed the damage induced by adenine as shown by reduced kidney injury and fibrosis markers which was further clearly evident in histological picture indicating the suitability of UA for use in CKD.

Safer approaches to therapeutic modulation of TGF-β signaling for respiratory disease

The transforming growth factor (TGF)-β cytokines play a central role in development and progression of chronic respiratory diseases. TGF-β overexpression in chronic inflammation, remodeling, fibrotic process and susceptibility to viral infection is established in the most prevalent chronic respiratory diseases including asthma, COPD, lung cancer and idiopathic pulmonary fibrosis. Despite the overwhelming burden of respiratory diseases in the world, new pharmacological therapies have been limited in impact. Although TGF-β inhibition as a therapeutic strategy carries great expectations, the constraints in avoiding compromising the beneficial pleiotropic effects of TGF-β, including the anti-proliferative and immune suppressive effects, have limited the development of effective pharmacological modulators. In this review, we focus on the pathways subserving deleterious and beneficial TGF-β effects to identify strategies for selective modulation of more distal signaling pathways that may result in agents with improved safety/efficacy profiles. Adverse effects of TGF-β inhibitors in respiratory clinical trials are comprehensively reviewed, including those of the marketed TGF-β modulators, pirfenidone and nintedanib. Precise modulation of TGF-β signaling may result in new safer therapies for chronic respiratory diseases.

Interleukin-27 Exerts Its Antitumor Effects by Promoting Differentiation of Hematopoietic Stem Cells to M1 Macrophages

The interleukin IL27 promotes expansion and differentiation of hematopoietic stem cells into myeloid progenitor cells. Many tumor-infiltrating myeloid cells exert immunosuppressive effects, but we hypothesized that the myeloid cells induced by IL27 would have antitumor activity. In this study, we corroborated this hypothesis as investigated in two distinct mouse transplantable tumor models. Malignant mouse cells engineered to express IL27 exhibited reduced tumor growth in vivo Correlated with this effect was a significant increase in the number of tumor-infiltrating CD11b⁺ myeloid cells exhibiting a reduced immunosuppressive activity. Notably, these CD11b⁺ cells were characterized by an activated M1 macrophage phenotype, on the basis of increased expression of inducible nitric oxide synthase and other M1 biomarkers. In vivo depletion of these cells by administering anti-Gr-1 eradicated the antitumor effects of IL27. When admixed with parental tumors, CD11b⁺ cells inhibited tumor growth and directly killed the tumor in a nitric oxide-dependent manner. Mechanistically, IL27 expanded Lineage^-Sca-1⁺c-Kit⁺ cells in bone marrow. Transplant experiments in Ly5.1/5.2 congenic mice revealed that IL27 directly acted on these cells and promoted their differentiation into M1 macrophages, which mobilized into tumors. Overall, our results illustrated how IL27 exerts antitumor activity by enhancing the generation of myeloid progenitor cells that can differentiate into antitumorigenic M1 macrophages.Significance: These findings show how the interleukin IL27 exerts potent antitumor activity by enhancing the generation of myeloid progenitor cells that can differentiate into antitumorigenic M1 macrophages.Cancer Res; 78(1); 182-94. ©2017 AACR.

Maresin 1 inhibits transforming growth factor-β1-induced proliferation, migration and differentiation in human lung fibroblasts

The myofibroblast has been implicated to be an important pathogenic cell in all fibrotic diseases, through synthesis of excess extracellular matrix. Lung fibroblast migration, proliferation and differentiation into a myofibroblast-like cell type are regarded as important steps in the formation of lung fibrosis. In the present study, the effect of maresin 1 (MaR 1), a pro-resolving lipid mediator, on transforming growth factor (TGF)-β1-stimulated lung fibroblasts was investigated, and the underlying molecular mechanisms were examined. The results of the present study demonstrated that MaR 1 inhibited TGF-β1-induced proliferative and migratory ability, assessed using MTT and scratch wound healing assays. The TGF-β1-induced expression of α-smooth muscle actin (α-SMA) and collagen type I, the hallmarks of myofibroblast differentiation, was decreased by MaR 1 at the mRNA and protein levels, determined using the reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Immunofluorescence demonstrated that MaR 1 downregulated the TGF-β1-induced expression of α-SMA. In addition, phosphorylated mothers against decapentaplegic homolog 2/3 (Smad2/3) and extracellular signal-related kinases (ERK) 1/2 were upregulated in TGF-β1-induced lung fibroblasts, and these effects were attenuated by MaR 1 administration. In conclusion, the results of the present study demonstrated that MaR 1 inhibited the TGF-β1-induced proliferation, migration and differentiation of human lung fibroblasts. These observed effects may be mediated in part by decreased phosphorylation of Smad2/3 and ERK1/2 signaling pathways. Therefore, MaR 1 may be a potential therapeutic approach to lung fibrotic diseases.

Pro-fibrotic pathway activation in trabecular meshwork and lamina cribrosa is the main driving force of glaucoma

While primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide, it still does not have a clear mechanism that can explain all clinical cases of the disease. Elevated IOP is associated with increased accumulation of extracellular matrix (ECM) proteins in the trabecular meshwork (TM) that prevents normal outflow of aqueous humor (AH) and has damaging effects on the fine mesh-like lamina cribrosa (LC) through which the optic nerve fibers pass. Applying a pathway analysis algorithm, we discovered that an elevated level of TGFβ observed in glaucoma-affected tissues could lead to pro-fibrotic pathway activation in TM and in LC. In turn, activated pro-fibrotic pathways lead to ECM remodeling in TM and LC, making TM less efficient in AH drainage and making LC more susceptible to damage from elevated IOP via ECM transformation in LC. We propose pathway targets for potential therapeutic interventions to delay or avoid fibrosis initiation in TM and LC tissues.

Crosstalk between Smad2/3 and specific isoforms of ERK in TGF-β1-induced TIMP-3 expression in rat chondrocytes

This study investigated the roles of ERK1 and ERK2 in transforming growth factor‐β1 (TGF‐β1)‐induced tissue inhibitor of metalloproteinases‐3 (TIMP‐3) expression in rat chondrocytes, and the specific roles of ERK1 and ERK2 in crosstalk with Smad2/3 were investigated to demonstrate the molecular mechanism of ERK1/2 regulation of TGF‐β1 signalling. To examine the interaction of specific isoforms of ERK and the Smad2/3 signalling pathway, chondrocytes were infected with LV expressing either ERK1 or ERK2 siRNA and stimulated with or without TGF‐β1. At indicated time‐points, TIMP‐3 expression was determined by real‐time PCR and Western blotting; p‐Smad3, nuclear p‐Smad3, Smad2/3, p‐ERK1/2 and ERK1/2 levels were assessed. And then, aggrecan, type II collagen and the intensity of matrix were examined. TGF‐β1‐induced TIMP‐3 expression was significantly inhibited by ERK1 knock‐down, and the decrease in TIMP‐3 expression was accompanied by a reduction of p‐Smad3 in ERK1 knock‐down cells. Knock‐down of ERK2 had no effect on neither TGF‐β1‐induced TIMP‐3 expression nor the quantity of p‐Smad3. Moreover, aggrecan, type II collagen expression and the intensity of matrix were significantly suppressed by ERK1 knock‐down instead of ERK2 knock‐down. Taken together, ERK1 and ERK2 have different roles in TGF‐β1‐induced TIMP‐3 expression in rat chondrocytes. ERK1 instead of ERK2 can regulate TGF‐β/Smad signalling, which may be the mechanism through which ERK1 regulates TGF‐β1‐induced TIMP‐3 expression.

Genetic and epigenetic regulation of intestinal fibrosis

Crohn's disease affects those individuals with polygenic risk factors. The identified risk loci indicate that the genetic architecture of Crohn's disease involves both innate and adaptive immunity and the response to the intestinal environment including the microbiome. Genetic risk alone, however, predicts only 25% of disease, indicating that other factors, including the intestinal environment, can shape the epigenome and also confer heritable risk to patients. Patients with Crohn's disease can have purely inflammatory disease, penetrating disease or fibrostenosis. Analysis of the genetic risk combined with epigenetic marks of Crohn's disease and other disease associated with organ fibrosis reveals common events are affecting the genes and pathways key to development of fibrosis. This review will focus on what is known about the mechanisms by which genetic and epigenetic risk factors determine development of fibrosis in Crohn's disease and contrast that with other fibrotic conditions.