New treatment and markers of prognosis for idiopathic pulmonary fibrosis: lessons learned from translational research

Research Progress of Respiratory Disease and Idiopathic Pulmonary Fibrosis Based on Artificial Intelligence

Machine Learning (ML) is an algorithm based on big data, which learns patterns from the previously observed data through classifying, predicting, and optimizing to accomplish specific tasks. In recent years, there has been rapid development in the field of ML in medicine, including lung imaging analysis, intensive medical monitoring, mechanical ventilation, and there is need for intubation etiology prediction evaluation, pulmonary function evaluation and prediction, obstructive sleep apnea, such as biological information monitoring and so on. ML can have good performance and is a great potential tool, especially in the imaging diagnosis of interstitial lung disease. Idiopathic pulmonary fibrosis (IPF) is a major problem in the treatment of respiratory diseases, due to the abnormal proliferation of fibroblasts, leading to lung tissue destruction. The diagnosis mainly depends on the early detection of imaging and early treatment, which can effectively prolong the life of patients. If the computer can be used to assist the examination results related to the effects of fibrosis, a timely diagnosis of such diseases will be of great value to both doctors and patients. We also previously proposed a machine learning algorithm model that can play a good clinical guiding role in early imaging prediction of idiopathic pulmonary fibrosis. At present, AI and machine learning have great potential and ability to transform many aspects of respiratory medicine and are the focus and hotspot of research. AI needs to become an invisible, seamless, and impartial auxiliary tool to help patients and doctors make better decisions in an efficient, effective, and acceptable way. The purpose of this paper is to review the current application of machine learning in various aspects of respiratory diseases, with the hope to provide some help and guidance for clinicians when applying algorithm models.

Comparison of 4 kinds of traditional Chinese medicine injections to assist in improving clinical indicators of patients with idiopathic pulmonary fibrosis: A systematic review and network meta-analysis

BACKGROUND

At present, apart from lung transplantation, no drugs can effectively treat idiopathic pulmonary fibrosis (IPF). Therefore, it is imperative to explore new drugs to control or treat it. Traditional Chinese medicine (TCM) injections have been widely used in the field of IPF, but there is no comparison of their efficacy in the assisted improvement of IPF. Therefore, the purpose of this study is to network meta-analyze the efficacy and safety of 4 kinds of commonly used TCM injections assisted by conventional treatment to improve the disease.

METHODS

Used a computer to find the Randomized Controlled Trials (RCTs) from the 8 major databases (PubMed, EMbase, CENTRAL, MEDLINE, CBM, China National Knowledge Infrastructure, WanFang Database and VIP Chinese Science). Cochrane's risk assessment tool was used to evaluate the quality of the literature. The Grading of Recommendations Assessment, Development and Evaluation approach served to assess the certainty in the evidence of direct and indirect estimates. Revman5.3 (Review Manager (RevMan) Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.) and stata14.0 (Stata/SE 14.0 for Windows (64-bit). Revision Apr 22, 2015.Copyright 1985-2015 StataCorp LP). were used for Statistical analysis. Registration number: CRD42020220570.

RESULTS

After layer-by-layer screening, 20 RCTs were finally included, which include a total of 1363 patients and 4 kinds of RCT of TCM injection (12 studies on Danhong injection, 5 studies on Ligustrazine injection, 2 studies on Huangqi injection and 1 study on Dazhu hongjingtian injection). The results showed: Clinical effective rate: Danhong Injection (Odds ratio [OR] = 3.94, 95% CI [2.34, 6.64], moderate certainty of evidence), Huangqi injection (OR = 3.40, 95% CI [1.38, 8.41], moderate certainty of evidence) and Ligustrazine injection (OR = 2.74, 95% CI [1.62, 4.64], moderate certainty of evidence) combined with conventional treatment had better curative efficacy than that of the conventional treatment group. SUCRA Ranking: Danhong (80.5) > Huangqi (68.5) > Ligustrazine (52.9) > Dazhu hongjingtian (44.3) > Conventional treatment (3.8); Forced Expiratory Volume In 1s/Forced vital capacity%: SUCRA Ranking: Danhong (80.0) > Ligustrazine (62.9) > Conventional treatment (2.1); Carbon monoxide diffusing capacity%: SUCRA Ranking: Ligustrazine (89.9) > Dazhu hongjingtian (63.4) > Danhong (44.9) > Conventional treatment (1.8); Partial pressure of Oxygen: SUCRA Ranking: Dazhu Hongjingtian (87.1) > Danhong (78.8) > Ligustrazine (34.0) > Conventional treatment (0.0); Partial pressure of carbon dioxide: SUCRA Ranking: Danhong (99.3) > Ligustrazine (50.3) > Conventional treatment (0.4). No obvious adverse reactions were found in all studies.

CONCLUSION

The four TCM injections combined with conventional treatment can effectively improve the clinical indicators of patients with IPF, and the improvement effect of Danhong injection was more obvious.

Mechanical Feed-Forward Loops Contribute to Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis is a progressive scarring disease characterized by extracellular matrix accumulation and altered mechanical properties of lung tissue. Recent studies support the hypothesis that these compositional and mechanical changes create a progressive feed-forward loop in which enhanced matrix deposition and tissue stiffening contribute to fibroblast and myofibroblast differentiation and activation, which further perpetuates matrix production and stiffening. The biomechanical properties of tissues are sensed and responded to by mechanotransduction pathways that facilitate sensing of changes in mechanical cues by tissue resident cells and convert the mechanical signals into downstream biochemical signals. Although our understanding of mechanotransduction pathways associated with pulmonary fibrosis remains incomplete, recent progress has allowed us to begin to elucidate the specific mechanisms supporting fibrotic feed-forward loops. The mechanosensors discussed here include integrins, Piezo channels, transient receptor potential channels, and nonselective ion channels. Also discussed are downstream transcription factors, including myocardin-related transcription factor and Yes-associated protein/transcriptional coactivator with PDZ-binding motif. This review describes mechanosensors and mechanotransduction pathways associated with fibrosis progression and highlights promising therapeutic insights.

FGFR2 Is Required for AEC2 Homeostasis and Survival after Bleomycin-induced Lung Injury

Alveolar epithelial cell (AEC) injury is central to the pathogenesis of pulmonary fibrosis. Epithelial FGF (fibroblast growth factor) signaling is essential for recovery from hyperoxia- and influenza-induced lung injury, and treatment with FGFs is protective in experimental lung injury. The cell types involved in the protective effect of FGFs are not known. We hypothesized that FGF signaling in type II AECs (AEC2s) is critical in bleomycin-induced lung injury and fibrosis. To test this hypothesis, we generated mice with tamoxifen-inducible deletion of FGFR1-3 (fibroblast growth factor receptors 1, 2, and 3) in surfactant protein C-positive (SPC⁺) AEC2s (SPC triple conditional knockout [SPC-TCKO]). In the absence of injury, SPC-TCKO mice had fewer AEC2s, decreased Sftpc (surfactant protein C gene) expression, increased alveolar diameter, and increased collagen deposition. After intratracheal bleomycin administration, SPC-TCKO mice had increased mortality, lung edema, and BAL total protein, and flow cytometry and immunofluorescence revealed a loss of AEC2s. To reduce mortality of SPC-TCKO mice to less than 50%, a 25-fold dose reduction of bleomycin was required. Surviving bleomycin-injured SPC-TCKO mice had increased collagen deposition, fibrosis, and ACTA2 expression and decreased epithelial gene expression. Inducible inactivation of individual Fgfr2 or Fgfr3 revealed that Fgfr2, but not Fgfr3, was responsible for the increased mortality and lung injury after bleomycin administration. In conclusion, AEC2-specific FGFR2 is critical for survival in response to bleomycin-induced lung injury. These data also suggest that a population of SPC⁺ AEC2s require FGFR2 signaling for maintenance in the adult lung. Preventing epithelial FGFR inhibition and/or activating FGFRs in alveolar epithelium may therefore represent a novel approach to treating lung injury and reducing fibrosis.

Effects of Ginkgo biloba leaf extract, shenmai and matrine on a human embryonic lung fibroblast fibrosis model

The aim of the present study was to investigate the effects of Ginkgo biloba leaf extract (GBLE), shenmai (S), and matrine (M) on human embryonic lung fibroblasts (HELFs). HELFs were allocated into the following groups: Group A (control group), group B [transforming growth factor β1 (TGF-β1) model group], groups C1-3 (TGF-β1 + low-, moderate- and high-dose GBLE), groups D1-3 (TGF-β1 + low-, moderate- and high-dose S) and groups E1-3 (TGF-β1 + low-, moderate- and high-dose oM). Cell proliferation was assessed with an MTT assay and apoptosis was measured by annexin V/propidium iodide double staining and flow cytometry analysis. Collagen type I (COL-I), collagen type III (COL-III), α-smooth muscle actin (α-SMA) and extracellular superoxide dismutase (ECSOD) mRNA expression levels were measured using semi-quantitative reverse transcription-polymerase chain reaction, and protein content was measured using ELISA. The cell growth inhibition rates of the S groups were significantly higher than those of the other treatment groups (P<0.05). The rate of apoptosis was significantly increased in the treatment groups compared with the model group (P<0.05), and S induced a significant increase in HELF apoptosis compared with the other treatment groups (P<0.05). The mRNA and protein expressions of COL-III, COL-I and α-SMA in the GBLE, S and M groups were significantly decreased, while the expression of ECSOD was significantly increased when compared with the model group (P<0.05). In conclusion, GBLE, S and M inhibited the pro-fibrotic role of TGF-β1 by targeting different steps in TGF-β1-mediated fibrosis.

Transforming growth factor-beta 1 in humidifier disinfectant-associated children's interstitial lung disease

BACKGROUND

Humidifier disinfectant-associated children's interstitial lung disease has an unpredictable clinical course with a high morbidity and mortality.

OBJECTIVES

To evaluate the differences in clinical findings between survivors and non-survivors of humidifier disinfectant-associated children's interstitial lung disease. To evaluate dynamic changes in serum cytokines related to inflammation and fibrosis in lung injury, and to determine whether these changes are predictive of survival in this disease.

METHODS

We evaluated 17 children with humidifier disinfectant-associated children's interstitial lung disease, from whom serum samples were obtained weekly during hospitalization. The severity of chest tomographic and lung pathologic findings was scored. Levels of several cytokines were measured in the serial serum samples.

RESULTS

Seven of the 17 children were survivors. Compared to survivors, non-survivors had greater ground-glass attenuation on follow-up chest tomography, higher admission neutrophil counts, and more macrophages on pathologic findings. Transforming growth factor-beta 1 persisted at an elevated level (1,000-1,500 pg/ml) in survivors, whereas it decreased abruptly in non-survivors. At the time of this decrease, non-survivors had clinical worsening of their respiratory failure. Transforming growth factor-beta 1 was positively correlated with PaO2 /FiO2 (r = 0.481, P < 0.0001).

CONCLUSIONS

Non-survivors exhibited more inflammatory clinical findings than survivors. Transforming growth factor-beta 1 remained elevated in survivors, suggesting that it affected the clinical course of humidifier disinfectant-associated children's interstitial lung disease. The prognosis of this lung disease may depend more on controlling excessive inflammation and repairing damaged lung than on fibrosis, and transforming growth factor-beta 1 may play a key role in this process.

Fibroblast growth factor 2 is required for epithelial recovery, but not for pulmonary fibrosis, in response to bleomycin

The pathogenesis of pulmonary fibrosis involves lung epithelial injury and aberrant proliferation of fibroblasts, and results in progressive pulmonary scarring and declining lung function. In vitro, fibroblast growth factor (FGF) 2 promotes myofibroblast differentiation and proliferation in cooperation with the profibrotic growth factor, transforming growth factor-β1, but the in vivo requirement for FGF2 in the development of pulmonary fibrosis is not known. The bleomycin model of lung injury and pulmonary fibrosis was applied to Fgf2 knockout (Fgf2(-/-)) and littermate control mice. Weight loss, mortality, pulmonary fibrosis, and histology were analyzed after a single intranasal dose of bleomycin. Inflammation was evaluated in bronchoalveolar lavage (BAL) fluid, and epithelial barrier integrity was assessed by measuring BAL protein and Evans Blue dye permeability. Fgf2 is expressed in mouse and human lung epithelial and inflammatory cells, and, in response to bleomycin, Fgf2(-/-) mice have significantly increased mortality and weight loss. Analysis of BAL fluid and histology show that pulmonary fibrosis is unaltered, but Fgf2(-/-) mice fail to efficiently resolve inflammation, have increased BAL cellularity, and, importantly, deficient recovery of epithelial integrity. Fgf2(-/-) mice similarly have deficient recovery of club cell secretory protein(+) bronchial epithelium in response to naphthalene. We conclude that FGF2 is not required for bleomycin-induced pulmonary fibrosis, but rather is essential for epithelial repair and maintaining epithelial integrity after bleomycin-induced lung injury in mice. These data identify that FGF2 acts as a protective growth factor after lung epithelial injury, and call into question the role of FGF2 as a profibrotic growth factor in vivo.

Epigenetic targets for novel therapies of lung diseases

In spite of substantial advances in defining the immunobiology and function of structural cells in lung diseases there is still insufficient knowledge to develop fundamentally new classes of drugs to treat many lung diseases. For example, there is a compelling need for new therapeutic approaches to address severe persistent asthma that is insensitive to inhaled corticosteroids. Although the prevalence of steroid-resistant asthma is 5-10%, severe asthmatics require a disproportionate level of health care spending and constitute a majority of fatal asthma episodes. None of the established drug therapies including long-acting beta agonists or inhaled corticosteroids reverse established airway remodeling. Obstructive airways remodeling in patients with chronic obstructive pulmonary disease (COPD), restrictive remodeling in idiopathic pulmonary fibrosis (IPF) and occlusive vascular remodeling in pulmonary hypertension are similarly unresponsive to current drug therapy. Therefore, drugs are needed to achieve long-acting suppression and reversal of pathological airway and vascular remodeling. Novel drug classes are emerging from advances in epigenetics. Novel mechanisms are emerging by which cells adapt to environmental cues, which include changes in DNA methylation, histone modifications and regulation of transcription and translation by noncoding RNAs. In this review we will summarize current epigenetic approaches being applied to preclinical drug development addressing important therapeutic challenges in lung diseases. These challenges are being addressed by advances in lung delivery of oligonucleotides and small molecules that modify the histone code, DNA methylation patterns and miRNA function.

miR-92a regulates TGF-β1-induced WISP1 expression in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common and fatal form of idiopathic interstitial pneumonia. MicroRNAs (miRNAs), short, single-stranded RNAs that regulate protein expression in a post-transcriptional manner, have recently been demonstrated to contribute to IPF pathogenesis. We have previously identified WNT1-inducible signaling pathway protein 1 (WISP1) as a highly expressed pro-fibrotic mediator in IPF, but the underlying mechanisms resulting in increased WISP1 expression, remain elusive. Here, we investigated whether WISP1 is a target of miRNA regulation. We applied a novel supervised machine learning approach, which predicted miR-30a/d and miR-92a target sites in regions of the human WISP1 3'UTR preferentially bound by the miRNA ribonucleoprotein complex. Both miRNAs were decreased in IPF samples, whereas WISP1 protein was increased. We demonstrated further that transforming growth factor (TGF)-β1-induced WISP1 expression in primary lung fibroblasts in vitro and lung homogenates in vivo. Notably, miR-30a and miR-92a reversed TGF-β1-induced WISP1 mRNA expression in lung fibroblasts. Moreover, miR-92a inhibition increased WISP1 protein expression in lung fibroblasts. An inverse relationship for WISP1 and miR-92a was found in a TGF-β1 dependent lung fibrosis model in vivo. Finally, we found significantly increased WISP1 expression in primary IPF fibroblasts, which negatively correlated with miR-92a level ex vivo. Altogether, our findings indicate a regulatory role of miR-92a for WISP1 expression in pulmonary fibrosis.