Human recombinant interferon-alpha2a and interferon-alphaA/D have different effects on bleomycin-induced lung injury

Lack of bombesin receptor-activated protein attenuates bleomycin-induced pulmonary fibrosis in mice

Enhanced autophagic activity in fibroblasts due to lack of BRAP homologous protein might contribute to the resistance to pulmonary fibrosis in mice.

Bombesin receptor–activated protein (BRAP) was found to express in the interstitial cells of human fibrotic lungs with unknown function. Its homologous protein, encoded by BC004004 gene, was also present in mouse lung tissues. We used BC004004^−/− mice which lack BRAP homologous protein expression to establish a bleomycin-induced lung fibrotic model. After bleomycin treatment, BC004004^−/− mice exhibited attenuation of pulmonary injury and less pulmonary fibrosis. Fibroblasts from BC004004^−/− mice proliferated at a lower rate and produced less collagen. Autophagy-related gene 5 (ATG5) was identified as a partner interacting with human BRAP. Lacking BRAP homologous protein led to enhanced autophagy activity in mouse lung tissues as well as in isolated lung fibroblasts, indicating a negative regulatory role of this protein in autophagy via interaction with ATG5. Enhanced autophagy process in fibroblasts due to lack of BRAP homologous protein might contribute to the resistance of BC004004^−/− mice to pulmonary fibrosis.

Expression profiles analysis identifies specific interferon-stimulated signatures as potential diagnostic and predictive indicators of JAK2V617F+ myelofibrosis

Objective: This study aimed to identify specific dysregulated genes with potential diagnostic and predictive values for JAK2V617F⁺ myelofibrosis.

Methods: Two gene expression datasets of CD34⁺ hematopoietic stem and progenitor cells (HSPCs) from patients with JAK2V617F⁺ myeloproliferative neoplasm (MPN) [n = 66, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)] and healthy controls (HC) (n = 30) were acquired from the GEO (Gene Expression Omnibus) database. The differentially expressed genes (DEGs) were screened between each JAK2V617F⁺ MPN entity and HC. Subsequently, functional enrichment analyses, including Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, and Gene Set Enrichment Analysis (GSEA), were conducted to decipher the important biological effects of DEGs. Protein–protein interaction (PPI) networks of the DEGs were constructed to identify hub genes and significant modules. Another two gene expression profiles of patients with JAK2V617F⁺ MPN [n = 23, including PV, ET, secondary myelofibrosis (SMF), and PMF] and HC (n = 6) from GEO were used as external validation datasets to prove the reliability of the identified signatures.

Results: KEGG analysis revealed the upregulated genes in three JAK2V617F⁺ MPN entities compared with HC were essentially enriched in inflammatory pathways and immune response signaling pathways, and the number of these pathways enriched in PMF was obviously more than that in PV and ET. Following the PPI analysis, 10 genes primarily related to inflammation and immune response were found upregulated in different JAK2V617F⁺ MPN entities. In addition, Reactome enrichment analysis indicated that interferon signaling pathways were enriched specifically in PMF but not in PV or ET. Furthermore, several interferon (IFN)-stimulated genes were identified to be uniquely upregulated in JAK2V617F⁺ PMF. The external datasets validated the upregulation of four interferon-related genes (OAS1, IFITM3, GBP1, and GBP2) in JAK2V617F⁺ myelofibrosis. The receiver operating characteristic (ROC) curves indicate that the four genes have high area under the ROC curve (AUC) values when distinguishing JAK2V617F⁺ myelofibrosis from PV or ET.

Conclusion: Four interferon-stimulated genes (OAS1, IFITM3, GBP1, and GBP2) exclusively upregulated in JAK2V617F⁺ myelofibrosis might have the potential to be the auxiliary molecular diagnostic and predictive indicators of myelofibrosis.

Vitamin D suppresses bleomycin-induced pulmonary fibrosis by targeting the local renin-angiotensin system in the lung

Idiopathic pulmonary fibrosis (IPF) is a severe disorder leading to progressive and irreversible loss of pulmonary function. In this study we investigated the anti-fibrotic effect of vitamin D using a mouse model of IPF. Lung fibrosis was induced with bleomycin in vitamin D-sufficient and vitamin D-deficient C57BL/6 mice. We found that treatment with active vitamin D analog paricalcitol prevented mouse body weight loss and alleviated lung fibrosis, whereas vitamin D deficiency severely aggravated lung injury. At the molecular level, paricalcitol treatment suppressed the induction of fibrotic inducer TGF-β and extracellular matrix proteins α-SMA, collagen type I and fibronectin in the lung, whereas vitamin D deficiency exacerbated the induction of these proteins. Interestingly, bleomycin treatment activated the local renin–angiotensin system (RAS) in the lung, manifested by the induction of renin, angiotensinogen, angiotensin II and angiotensin receptor type 1 (AT1R). Paricalcitol treatment suppressed the induction of these RAS components, whereas vitamin D deficiency enhanced the activation of the lung RAS. We also showed that treatment of bleomycin-induced vitamin D-deficient mice with AT1R antagonist losartan relieved weight loss, substantially ameliorated lung fibrosis and markedly blocked TGF-β induction in the lung. Moreover, we demonstrated that in lung fibroblast cultures, TGF-β and angiotensin II synergistically induced TGF-β, AT1R, α-SMA, collagen type I and fibronectin, whereas 1,25-dihydroxyvitamin D markedly suppressed the induction of these fibrotic markers. Collectively, these observations strongly suggest that vitamin D mitigates lung fibrosis by blocking the activation of the lung RAS in this mouse model of IPF.

Targeting Runt-Related Transcription Factor 1 Prevents Pulmonary Fibrosis and Reduces Expression of Severe Acute Respiratory Syndrome Coronavirus 2 Host Mediators

Pulmonary fibrosis (PF) can arise from unknown causes, as in idiopathic PF, or as a consequence of infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current treatments for PF slow, but do not stop, disease progression. We report that treatment with a runt-related transcription factor 1 (RUNX1) inhibitor (Ro24-7429), previously found to be safe, although ineffective, as a Tat inhibitor in patients with HIV, robustly ameliorates lung fibrosis and inflammation in the bleomycin-induced PF mouse model. RUNX1 inhibition blunted fundamental mechanisms downstream pathologic mediators of fibrosis and inflammation, including transforming growth factor-β1 and tumor necrosis factor-α, in cultured lung epithelial cells, fibroblasts, and vascular endothelial cells, indicating pleiotropic effects. RUNX1 inhibition also reduced the expression of angiotensin-converting enzyme 2 and FES Upstream Region (FURIN), host proteins critical for SARS-CoV-2 infection, in mice and in vitro. A subset of human lungs with SARS-CoV-2 infection overexpress RUNX1. These data suggest that RUNX1 inhibition via repurposing of Ro24-7429 may be beneficial for PF and to battle SARS-CoV-2, by reducing expression of viral mediators and by preventing respiratory complications.

Indoline-3-propionate and 3-aminopropyl carbamates reduce lung injury and pro-inflammatory cytokines induced in mice by LPS

BACKGROUND AND PURPOSE

In the search for safer and effective anti-inflammatory agents, we investigated the effect of methyl indoline-3-propionate and indoline-3-(3-aminopropyl) carbamates on LPS-induced lung injury and pro-inflammatory cytokines in mice. Their mechanism of action was determined in murine peritoneal macrophages.

EXPERIMENTAL APPROACH

Lung injury was induced by intratracheal infusion of LPS and assessed by the change in lung weight and structure by light microscopy after staining by haematoxylin and eosin. In LPS-activated macrophages, MAPK proteins and IκBα were measured by Western blotting and the transcription factors, AP-1 and NF-κB by electromobility shift assay. Cytokines in the plasma and spleen of mice injected with LPS were measured by elisa-based assay.

KEY RESULTS

AN917 and AN680 (1-10 pM) decreased TNF-α protein in macrophages by inhibiting phosphorylation of p38 MAPK, IκBα degradation and activation of AP-1 and NF-κB without affecting cell viability. In vivo, these compounds (10 μmol · kg(-1)) markedly decreased lung injury induced by LPS and the elevation of TNF-α and IL-6 in lung, plasma and spleen. Activation of α-7nACh receptors contributed to the reduction of TNF-α by AN917, which inhibited AChE in the spleen by 35%.

CONCLUSION AND IMPLICATIONS

Indoline carbamates are potent inhibitors of pro-inflammatory mediators in murine macrophages and in mice injected with LPS, acting via the p38 MAPK, AP-1 and NF-κB cascades. Indirect α-7nACh receptor activation by AN917, through inhibition of AChE, contributes to its anti-inflammatory effect. Indoline carbamates may have therapeutic potential for lung injury and other diseases associated with chronic inflammation without causing immunosuppression.

Association of Interferon- and transforming growth factor β-regulated genes and macrophage activation with systemic sclerosis-related progressive lung fibrosis

OBJECTIVE

Systemic sclerosis (SSc)-related interstitial lung disease (ILD) is one of the leading causes of mortality. We undertook this study to analyze the gene expression of lung tissue in a prospective cohort of patients with SSc-related ILD and to compare it with that in control lungs and with 2 prospective clinical parameters in order to understand the molecular pathways implicated in progressive lung disease.

METHODS

Lung tissue was obtained by open lung biopsy in 28 consecutive patients with SSc-related ILD and in 4 controls. High-resolution computed tomography (HRCT) and pulmonary function testing (PFT) were performed at baseline and 2-3 years after treatment based on lung histologic classification. Microarray analysis was performed, and the results were correlated with changes in the HRCT score (FibMax) and PFT values. Quantitative polymerase chain reaction (qPCR) and immunohistochemistry were used to confirm differential levels of messenger RNA and protein.

RESULTS

Lung microarray data distinguished patients with SSc-related ILD from healthy controls. In the lungs of patients with SSc-related ILD who had nonspecific interstitial pneumonia (NSIP), expressed genes included macrophage markers, chemokines, collagen, and transforming growth factor β (TGFβ)- and interferon (IFN)-regulated genes. Expression of these genes correlated with progressive lung fibrosis defined by the change in FibMax. Immunohistochemistry confirmed increased markers of collagen (COL1A1), IFN (OAS1 and IFI44), and macrophages (CCL18 and CD163), and the positive correlation with the change in FibMax was confirmed by qPCR in a larger group of SSc patients with NSIP. Several genes correlated with both the change in FibMax (r > 0.4) and the change in % predicted forced vital capacity (r < -0.1), including IFN and macrophage markers, chemokines, and heat-shock proteins.

CONCLUSION

These results highlight major pathogenic pathways relevant to progressive pulmonary fibrosis in SSc-related ILD: macrophage emigration and activation, and up-regulated expression of TGFβ- and IFN-regulated genes.

Effect of IL-2-Bax, a novel interleukin-2-receptor-targeted chimeric protein, on bleomycin lung injury

The role of lymphocytes in the pathogenesis of lung fibrosis is not clear, but the weight of the evidence supports a pro-fibrotic effect for lymphocytes. The high-affinity interleukin-2 receptor (haIL-2R) is expressed on activated, but not quiescent, T lymphocytes. This selective expression of haIL-2R provides the basis for therapeutic strategies that target IL-2R-expressing cells. We hypothesized that elimination of activated lymphocytes by IL-2R-targeted chimeric proteins might ameliorate lung fibrosis. We investigated the effects of IL-2-Bax, a novel apoptosis-inducing IL-2R-targeted chimeric protein, on bleomycin-induced lung injury in mice. Treatment groups included (i) a single intratracheal instillation of bleomycin and twice-daily intraperitoneal injections of IL-2-Bax; (ii) intratracheal bleomycin and intraperitoneal IL-2-PE66(4Glu), an older-generation chimeric protein; (iii) intratracheal bleomycin/intraperitoneal PBS; (iv) intratracheal saline/intraperitoneal PBS. Lung injury was evaluated 14 days after intratracheal instillation by cell count in bronchoalveolar lavage (BAL) fluid, semi-quantitative and quantitative histomorphological measurements and by biochemical analysis of lung hydroxyproline. Bleomycin induced a BAL lymphocytosis that was significantly attenuated by IL-2-Bax and IL-2-PE66(4Glu). However, morphometric parameters and lung hydroxyproline were unaffected by the chimeric proteins. These results show that IL-2-Bax reduces the lymphocytic infiltration of the lungs in response to bleomycin, but this effect is not accompanied by a decrease in lung fibrosis.

Medical treatment for pulmonary fibrosis: current trends, concepts, and prospects

A diagnosis of idiopathic pulmonary fibrosis (IPF) carries a poor prognosis, with our currently available therapies offering little clinical benefit. Unfortunately, recent major advances in our understanding of the clinical and biologic features of this disease have not been matched by similar advances in treatment. This is likely because of the complex cascade of biologic and pathobiologic events that occurs in IPF. The necessary, and desperately needed, next generation of therapies, focused on specific molecular targets thought to play pivotal roles in the development and progression of fibrosis, are under active investigation.

Role of interferon-gamma in the evolution of murine bleomycin lung fibrosis

IFN-gamma production is upregulated in lung cells (LC) of bleomycin-treated C57BL/6 mice. The present study characterizes the time course, cellular source, and regulation of IFN-gamma expression in bleomycin-induced lung injury. IFN-gamma mRNA in LC from bleomycin-treated mice peaked 3 days after intratracheal instillation. IFN-gamma protein levels were increased at 6 days, as was the percentage of LC expressing IFN-gamma. CD4+, CD8+, and natural killer cells each contributed significantly to IFN-gamma production. IL-12 mRNA levels were increased at 1 day in LC of bleomycin-treated mice. Anti-IL-12 and anti-IL-18 antibodies decreased IFN-gamma production by these cells. To define the role of endogenous IFN-gamma in the evolution of bleomycin lung injury, we compared the effect of bleomycin in mice with a targeted knockout mutation of the IFN-gamma gene (IFN-gamma knockout) and wild-type mice. At 14 days after intratracheal bleomycin, total bronchoalveolar lavage cell counts and lung hydroxyproline were decreased in IFN-gamma knockouts compared with wild-type animals. There was no difference in morphometric parameters of fibrosis. Our data show that enhanced IFN-gamma production in the lungs of bleomycin-treated mice is at least partly IL-12 and IL-18 dependent. Absence of IFN-gamma in IFN-gamma knockout mice does not increase pulmonary fibrosis. Endogenous IFN-gamma may play a proinflammatory or profibrotic role in bleomycin-induced lung fibrosis.

Interferons and their application in the diseases of the lung

Interferons (IFNs) are a family of cytokine mediators that are critically involved in alerting the cellular immune system to viral infections of host cells. There are three major classes of IFNs, as follows: IFN-alpha; IFN-beta; and IFN-gamma. IFNs are being investigated and applied in various respiratory disorders, including interstitial lung diseases, lung cancer, malignant mesothelioma, malignant pleural effusions, and respiratory infections. Recent promising preliminary results concerning patients with idiopathic pulmonary fibrosis who have been treated with IFN-gamma1b should prompt the performance of further confirmatory well-designed multicenter trials. IFN-gamma is emerging as an important cytokine for use in the treatment of patients with infectious diseases, including multidrug-resistant pulmonary TB. A better understanding of IFN biology, indications, side effect profiles, and toxicity management will aid in optimizing its use in the treatment of patients. The purpose of this article is, therefore, to review the current clinical use of IFNs in the treatment of patients with respiratory diseases.

Bleomycin-induced lung fibrosis in IL-4-overexpressing and knockout mice

The role of IL-4 in the development of lung fibrosis is as yet unclear. Bleomycin (Bleo) or saline (Sal) was injected intratracheally into three groups of C57BL/6J mice: transgenic animals that overexpressed IL-4 (IL-4 TG, n = 14), mice with a targeted knockout mutation of the IL-4 gene (IL-4 KO, n = 11), and wild-type (WT, n = 13) mice. At 14 days, lung fibrosis was evaluated by hydroxyproline measurement and by quantitative image analysis of fibrosis fraction and alveolar wall area fraction. Bronchoalveolar lavage cell counts in all Bleo-treated groups demonstrated an increased percentage of lymphocytes with a corresponding decrease in the percentage of macrophages. Comparing Bleo- to Sal-treated controls within each group of mice showed increases in all lung fibrosis parameters in IL-4 KO and WT, but not in any of the parameters in IL-4 TG mice. The severity of Bleo-induced fibrotic response was decreased in overexpressed IL-4 TG compared with IL-4 KO mice. These data negate a critical profibrotic role for IL-4 in Bleo-induced lung fibrosis.

[Do the interferons have an antifibrotic action? The internist's point of view]

PURPOSE

The antifibrotic action of interferon alpha on the liver is now established in hepatitis C (cf. article by T. Poynard). Numerous in vitro experimental evidences may lead people into believing in the efficacy of interferon gamma in patients with mucous membrane and pulmonary fibrosis.

CURRENT KNOWLEDGE AND KEY POINTS

A randomized study has confirmed the efficacy of interferon gamma in the idiopathic pulmonary fibrosis, probably by an anti TGF beta action. Several open studies have shown the efficacy of interferon gamma in patients with post-radiation cutaneous fibrosis (Chernobyl survivors, sequelae of radiotherapy for cancer). In systemic sclerosis, several teams have shown that interferon gamma reduced collagen synthesis by sclerodermic fibroblasts in vitro. Four open studies have also confirmed the efficacy of interferon gamma in systemic sclerosis. In our experience concerning 20 patients with diffuse systemic sclerosis, the five years survival with long term therapy was 85% and we observed an improvement in the cutaneous suppleness in 40% of these cases. There was no serious side effect.

FUTURE PROSPECTS AND PROJECTS

These encouraging results need to be confirmed by large randomized studies in pulmonary fibrosis and systemic sclerosis. Other indications should be assessed, particularly extra-cutaneous radiation sequelae and in systemic fibrosis (retroperitoneal, mediastinal and cervical).

Cyclosporin A upmodulates bleomycin-induced pulmonary fibrosis in BALB/c mice

BACKGROUND

Intratracheal instillation of bleomycin (Bleo) into rodents serves as a model for human lung fibrosis. Various mouse strains respond differently to Bleo, and BALB/c mice are relatively resistant.

OBJECTIVE

Since T lymphocytes have been shown to play a major role in this model, the effect of the immunomodulator cyclosporin A (CyA) on lung fibrosis was studied in Bleo-'resistant' BALB/c mice.

METHODS

Pulmonary fibrosis was induced by a single intratracheal (IT) instillation of Bleo. One of the four following treatments was given to one of four groups of female BALB/c mice: (1) Bleo-CyA: IT Bleo and daily intraperitoneal (IP) injections of CyA 100 mg/day starting 1 day before IT instillation of Bleo; (2) Bleo-Sal: IT Bleo and IP injections of saline; (3) Sal-CyA: IT saline and IP CyA 100 mg/kg; (4) Sal-Sal: IT and IP saline. The animals were killed on day 14. Fibrosis was evaluated by analysis of hydroxyproline and by quantitative image analysis of the fibrosis fraction. Ex vivo IFN-gamma, IL-4, IL-13 and IL-5 secretion by peribronchial lymphatic tissue lymphocytes was measured.

RESULTS

Pretreatment with CyA upmodulated Bleo-induced lung fibrosis in the Bleo-'resistant' BALB/c mice; hydroxyproline was higher in Bleo-CyA compared to Bleo-Sal animals and both hydroxyproline and fibrosis fraction measurements were higher in Bleo-CyA compared to Sal-Sal. Cytokine secretion by lymphocytes demonstrated increased IFN-gamma/IL-4 and IFN-gamma/IL-13 mean secretion ratios in the Bleo-CyA animals compared to the Bleo-Sal animals.

CONCLUSIONS

These results indicate that CyA upmodulates Bleo-induced lung fibrosis in Bleo-'resistant' BALB/c mice by allowing the emergence of a Th1 inflammatory response.

Halofuginone does not reduce fibrosis in bleomycin-induced lung injury

Halofuginone, a coccidiostatic alkaloid, has anti-fibrotic properties, and may be useful as a therapeutic agent in lung fibrosis. To test this hypothesis we investigated the effect of halofuginone on bleomycin-induced lung fibrosis in Sprague-Dawley rats. Treatment groups included: (1) a single intratracheal (IT) instillation of 1.2U bleomycin, and intraperitoneal (IP) injection of halofuginone (0.5 mg/dose), every other day; (2) IT 1.2U bleomycin and IP distilled water (D.W.), every other day; (3) IT 0.8U bleomycin and daily IP halofuginone (0.5 mg/dose); (4) IT 0.8U bleomycin and daily IP D.W.; (5) IT saline and IP halofuginone, every other day; (6) IT saline and daily IP D.W.; (7) IT 0.625U bleomycin and oral halofuginone (10 mg/kg rodent lab chow); (8) IT 0.625U bleomycin and standard lab chow. Animals were studied 14 days after IT instillation. Lung injury was evaluated by total and differential cell count in bronchoalveolar lavage fluid, by a semi-quantitative morphological index of lung injury, and by biochemical analysis of lung hydroxyproline content. Overt signs of lung injury were apparent in bleomycin-treated rats by all measures. These changes were not affected by treatment with halofuginone, irrespective of the treatment regimen used. This study does not support the use of halofuginone to prevent or ameliorate lung fibrosis.

Time course of bleomycin-induced lung fibrosis

Intratracheal instillation (IT) of bleomycin is a widely used experimental model for lung fibrosis. In this study we describe the time-course of bleomycin-induced lung fibrosis in mice using computer-assisted morphometry. C57Bl/6J mice were treated with a single IT dose of bleomycin or control saline. Animals were killed 3, 6, 14 and 21 days post-IT. Lung injury was evaluated by analysis of bronchoalveolar lavage (BAL) fluid, hydroxyproline concentration in the lung, routine light microscopic examination resulting in a semiquantitative morphological index (SMI) of lung injury, and quantitative morphological measurements (fibrosis fraction and alveolar wall area fraction) aided by optimas image analysis software. Changes in BAL fluid attributed to bleomycin treatment include increased total cell count (days 14 and 21), and increased percentage of neutrophils (days 3 and 6) followed by a sustained increase in lymphocytes (days 6, 14 and 21). Hydroxyproline levels increased in bleomycin-treated mice on days 14 and 21. Median SMI grades were significantly elevated on days 3, 14 and 21. Computer-assisted morphometry demonstrated a 3-fold increase in fibrosis fraction and a 1.3-fold increase in wall area fraction in bleomycin-treated mice on day 14, with no further increase on day 21. These data also demonstrate that the most suitable time point for assessing lung fibrosis in this model is 14 days after IT instillation of bleomycin, based on the observation that at 14 days the animals developed extensive fibrosis, but had less variability in the fibrotic response and lower mortality than later at 21 days. Computer-assisted morphometry provides objective and quantitative measurements that are a useful tool for the evaluation of bleomycin-induced lung injury.