Relationship between the eosinophilia of bronchoalveolar lavage fluid (BALF) and the severity of pulmonary fibrosis induced by bleomycin in rats

Identifying oxidative stress-related biomarkers in idiopathic pulmonary fibrosis in the context of predictive, preventive, and personalized medicine using integrative omics approaches and machine-learning strategies

Background

Idiopathic pulmonary fibrosis (IPF) is a rare interstitial lung disease with a poor prognosis that currently lacks effective treatment methods. Preventing the acute exacerbation of IPF, identifying the molecular subtypes of patients, providing personalized treatment, and developing individualized drugs are guidelines for predictive, preventive, and personalized medicine (PPPM / 3PM) to promote the development of IPF. Oxidative stress (OS) is an important pathological process of IPF. However, the relationship between the expression levels of oxidative stress-related genes (OSRGs) and clinical indices in patients with IPF is unclear; therefore, it is still a challenge to identify potential beneficiaries of antioxidant therapy. Because PPPM aims to recognize and manage diseases by integrating multiple methods, patient stratification and analysis based on OSRGs and identifying biomarkers can help achieve the above goals.

Methods

Transcriptome data from 250 IPF patients were divided into training and validation sets. Core OSRGs were identified in the training set and subsequently clustered to identify oxidative stress-related subtypes. The oxidative stress scores, clinical characteristics, and expression levels of senescence-associated secretory phenotypes (SASPs) of different subtypes were compared to identify patients who were sensitive to antioxidant therapy to conduct differential gene functional enrichment analysis and predict potential therapeutic drugs. Diagnostic markers between subtypes were obtained by integrating multiple machine learning methods, their expression levels were tested in rat models with different degrees of pulmonary fibrosis and validation sets, and nomogram models were constructed. CIBERSORT, single-cell RNA sequencing, and immunofluorescence staining were used to explore the effects of OSRGs on the immune microenvironment.

Results

Core OSRGs classified IPF into two subtypes. Patients classified into subtypes with low oxidative stress levels had better clinical scores, less severe fibrosis, and lower expression of SASP-related molecules. A reliable nomogram model based on five diagnostic markers was constructed, and these markers' expression stability was verified in animal experiments. The number of neutrophils in the immune microenvironment was significantly different between the two subtypes and was closely related to the degree of fibrosis.

Conclusion

Within the framework of PPPM, this work comprehensively explored the role of OSRGs and their mediated cellular senescence and immune processes in the progress of IPF and assessed their capabilities aspredictors of high oxidative stress and disease progression,targets of the vicious loop between regulated pulmonary fibrosis and OS for targeted secondary and tertiary prevention, andreferences for personalized antioxidant and antifibrotic therapies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00334-4.

Identification and immune characteristics of molecular subtypes related to fatty acid metabolism in idiopathic pulmonary fibrosis

Background

Although fatty acid metabolism has been confirmed to be involved in the pathological process of idiopathic pulmonary fibrosis (IPF), systematic analyses on the immune process mediated by fatty acid metabolism-related genes (FAMRGs) in IPF remain lacking.

Methods

The gene expression data of 315 patients with IPF were obtained from Gene Expression Omnibus database and were divided into the training and verification sets. The core FAMRGs of the training set were identified through weighted gene co-expression network analysis. Then, the fatty acid metabolism-related subtypes in IPF were identified on the basis of k-means unsupervised clustering. The scores of fatty acid metabolism and the expression of the fibrosis biomarkers in different subtypes were compared, and functional enrichment analysis was carried out on the differentially expressed genes between subtypes. A random forest model was used to select important FAMRGs as diagnostic markers for distinguishing between subtypes, and a line chart model was constructed and verified by using other datasets and rat models with different degrees of pulmonary fibrosis. The difference in immune cell infiltration among subtypes was evaluated with CIBERSORT, and the correlation between core diagnostic markers and immune cells were analyzed.

Results

Twenty-four core FAMRGs were differentially expressed between the training set and normal samples, and IPF was divided into two subtypes. Significant differences were observed between the two subtypes in biological processes, such as linoleic acid metabolism, cilium movement, and natural killer (NK) cell activation. The subtype with high fatty acid metabolism had more severe pulmonary fibrosis than the other subtype. A reliable construction line chart model based on six diagnostic markers was constructed, and ABCA3 and CYP24A1 were identified as core diagnostic markers. Significant differences in immune cell infiltration were found between the two subtypes, and ABCA3 and CYP24A1 were closely related to NK cells.

Conclusion

Fatty acid metabolism and the immune process that it mediates play an important role in the occurrence and development of IPF. The analysis of the role of FAMRGs in IPF may provide a new potential therapeutic target for IPF.

Effects of three blood derived products on equine corneal cells, an in vitro study

BACKGROUND

Despite advances in therapy of corneal ulcerative diseases in horses, a vast number of cases require surgical intervention, due to poor response to treatment. Topical application of serum has been used for many years, based on its anticollagenolytic properties and the presence of growth factors promoting corneal wound healing. However, although other blood derived products i.e. platelet rich plasma (PRP), plasma rich in growth factors (PRGF) have been widely used in equine orthopaedics and in human ophthalmology, no reports of the effects of these blood derived products exist in equine ophthalmology.

OBJECTIVES

To determine in vitro effects of PRGF and PRP on equine corneal cells compared with serum.

STUDY DESIGN

Prospective controlled cohort study.

METHODS

Blood from 35 healthy horses was used to produce serum, PRGF (Endoret^® ), and PRP (E-PET™). Limbal- and stromal cells were isolated from healthy corneas of six horses and treated with 20% serum, 20% PRGF or 20% PRP. Proliferation rates and migration capacity were analysed in single cell cultures as well as co-culture systems.

RESULTS

Cell proliferation increased with PRP treatment, remained constant in PRGF treated cells, and declined upon serum treatment over a period of 48 h. Migration capacity was significantly enhanced with PRP treatment, compared with PRGF treatment. Intact leucocytes, mainly eosinophils, were only detected in PRP.

MAIN LIMITATIONS

Due to the study design use of autologous blood products on corneal cells was not possible.

CONCLUSIONS

The results demonstrate beneficial effects of PRP on proliferation as well as migration capacity of equine corneal cells in vitro. In vivo studies are warranted to determine further beneficial effects of PRP in horses with corneal ulcers.

Association of serum periostin with aspirin-exacerbated respiratory disease

BACKGROUND

Recent studies recommend periostin as a systemic biomarker of eosinophilic airway inflammation to predict responses to novel treatments that targets eosinophilic TH2-driven inflammation in asthmatic patients.

OBJECTIVE

To investigate the clinical implications of serum periostin levels in patients with aspirin-exacerbated respiratory disease (AERD) based on its overlapping TH2-mediated pathogenesis with the eosinophilic asthma.

METHODS

Serum periostin levels were measured by human periostin enzyme-linked immunosorbent assay (ELISA) in serum samples from 277 adults with asthma. Serum periostin levels were compared between patients with AERD and aspirin tolerant asthma (ATA) with other asthma phenotypes, such as severe or nonsevere asthma and eosinophilic or noneosinophilic asthma. The association of serum periostin levels with clinical parameters (including disease severity and comorbid condition) was analyzed.

RESULTS

Serum periostin levels were significantly higher in patients with AERD vs ATA, patients with severe asthma vs nonsevere asthma, and patients with eosinophilic asthma vs noneosinophilic asthma (P=.005, P=.02, and P=.001, respectively). Multivariate regression analysis revealed serum periostin levels as a significant parameter to predict AERD phenotype (P=.006) together with severe asthma phenotype (P=.04). In addition, serum periostin levels correlated with blood eosinophil counts (Spearman ñ = 0.244, P<.001) and sputum eosinophil counts (Spearman ñ = 0.261, P < 0.001). Higher serum periostin levels were noted in comorbid AERD patients with more severe chronic rhinosinusitis (Lund-Mackay stages 3 and 4) than those with less severe chronic rhinosinusitis (Lund-Mackay stages 1 and 2) (P = .03).

CONCLUSION

Serum periostin levels are significantly elevated in AERD patients and associated with AERD phenotype and disease severity.

Measurement of hydroxyproline in collagen with three different methods

Determination of the 4-hydroxy-l-proline (hydroxyproline) concentration may provide useful information for the diagnosis and prognosis of diseases caused by disorders of collagen metabolism. The objective of the present study was to apply liquid chromatography-mass spectrometry (LC-MS) to assess the hydroxyproline concentration. The hydroxyproline concentration in lung and liver tissues measured by LC-MS was compared with values obtained by a colorimetric method, as well as a fluorescence method using high-performance liquid chromatography (HPLC) from previous studies by our group. The determination of the hydroxyproline concentration by LC-MS was improved as compared with that using the colorimetric and HPLC methods, due to its simplicity, high sensitivity (pg level) and short separation time. These results suggested that utilizing the LC-MS method for measuring the hydroxyproline concentration would be advantageous for the diagnosis of diseases associated with abnormalities of collagen metabolism.

FELD better not thinking of metastases only when liver lesions appear after bleomycin-based treatment for non-seminoma testis from metastases

BACKGROUND

Bleomycin has become an integral part of chemotherapy in patients with germ-cell tumors. One of the most feared side effects is bleomycin-induced pneumonitis. In patients with mild or moderate BIP, radiological signs disappear almost completely within nine months after discontinuation of bleomycin treatment.

CASE PRESENTATION

We present a patient with a history of non seminoma of the testis and bleomycin-induced pneumonitis. During follow-up, regression of the hypothesis of eosinophilic migration to the liver after regression of bleomycin-induced pneumonitis is highly suspicious based on transient eosinophilia and focal eosinophilic liver disease.

CONCLUSION

As follow up may consist of CT scanning in germ-line tumor patients, transient eosinophilic liver lesions reported during regressive bleomycin-induced pneumonitis should not be presumed automatically as metastatic tumor relapse and require further sequential imaging and pathological examination.

Serine protease activity of Cur l 1 from Curvularia lunata augments Th2 response in mice

RATIONALE

Studies with mite allergens demonstrated that proteolytic activity augments allergic airway inflammation. This knowledge is limited to few enzyme allergens.

OBJECTIVE

The objective of this study is to investigate the effect of serine protease Cur l 1 from Curvularia lunata in airway inflammation/hyper-responsiveness.

METHODS

Cur l 1 was purified and inactivated using a serine protease inhibitor. Balb/c mice were sensitized with enzymatically active Cur l 1 or C. lunata extract. Sensitized mice were given booster dose on day 14 with active or inactivated Cur l 1. Intranasal challenge was given on day 28, 29, and 30. Airway hyper-responsiveness was measured by plethysmography. Blood, bronchoalveolar lavage fluid (BALF), spleen, and lungs from mice were analyzed for cellular infiltration, immunoglobulins, and cytokine levels.

RESULTS

Mice challenged with enzymatically active Cur l 1 demonstrated significantly higher airway inflammation than inactive Cur l 1 group mice (p < 0.01). There was a significant difference in serum IgE and IgG1 levels among mice immunized with active Cur l 1 and inactive Cur l 1 (p < 0.01). IL-4 and IL-5 were higher in BALF and splenocyte culture supernatant of active Cur l 1 than inactive Cur l 1 mice. Lung histology revealed increased eosinophil infiltration, goblet cell hyperplasia and mucus secretion in active group.

CONCLUSION

Proteolytic activity of Cur l 1 plays an important role in airway inflammation and the inactivated Cur l 1 has potential to be explored for immunotherapy.

Effect of proteolytic activity of Epicoccum purpurascens major allergen, Epi p 1 in allergic inflammation

Enzymes play an important role in inducing airway inflammation, but knowledge is limited to few proteins. This study was carried out to assess the role of Epi p 1, a serine protease of Epicoccum purpurascens, in inducing allergy and inflammation in a murine model. Balb/c mice were sensitized with Epi p 1 active protease (EAP) or Epicoccum extract. Subsequently, Epi p 1 sensitized mice were boosted on day 14 with EAP or inactivated protease (EIAP). Three intranasal challenges were given and mice were killed to obtain blood, bronchoalveolar lavage fluid (BALF), spleen and lung tissues. Cellular airways infiltration, immunoglobulin E (Ig)E titres and cytokine levels in BALF and splenocyte culture supernatant were compared. Mice immunized with EAP had higher Epi p 1-specific serum IgE and IgG1 than EIAP immunized mice (P < 0.01). There was a twofold difference in the number of eosinophils in BALF of EAP mice and EIAP mice (P < 0.01). A similar trend was recorded for eosinophil peroxidase activity (P < 0.05), indicating the role of proteolytic activity in inducing inflammation. Further, lung histology revealed increased leucocyte infiltration and airway narrowing, with higher inflammation scores in the EAP group than in the EIAP group. The lungs of EAP mice showed increased mucus and goblet cell metaplasia. Interleukin (IL)-4 and IL-5 levels were higher in BALF and splenocyte culture supernatant of EAP mice than in EIAP mice (P < 0.05), indicating a T helper 2 response. Proteolytic activity of Epi p 1 plays an important role in inducing allergic inflammation. The enzymatically inactive form may be investigated for immunotherapy.

[Neuromuscular biopsy and diagnosis of vasculitis]

One characteristic histological lesion on biopsy specimens is mandatory to establish the diagnosis of vasculitis. Combined nerve and muscle biopsies, by the same cutaneous incision, improve significantly the percentage of positive results. Nerve fragments should be taken in every patient presenting sensory manifestations. Such vasculitic lesions are present in medium-sized arterioles and/or small vessels, and correspond mainly to 4 necrotizing vasculitis: panarteritis nodosa (PAN), microscopic polyangiitis (MPA), Churg and Strauss syndrome and Wegener granulomatosis. Microvasculitis should be added to these classical entities, because it corresponds to small vessel wall infiltration by inflammatory cells, as observed in PAN and MPA, but without any necrosis. Microvasculitis has to be differentiated from the inflammatory cell infiltrates surrounding small vessels. However, such perivascular inflammatory cell infiltrates enable the diagnosis of probable vasculitis when associated with clusters of neo-vessels, hemosiderin deposits, or a focal damage of nerve fibers. Grossly, one third of vasculitis diagnosis is confirmed on muscle fragments, a second third on nerve fragments, and the last third on both nerve and muscle fragments. Moreover, in the search for vasculitis, an unpredicted diagnosis of lymphoma or amyloidosis is occasionally established on the neuro-muscular biopsy.

Inhibition of early and late phase allergic reactions by Euphorbia hirta L

A 95% ethanol extract from whole aerial parts of Euphorbia hirta (EH A001) showed antihistaminic, antiinflammatory and immunosuppressive properties in various animal models. EH A001 inhibited rat peritoneal mast cell degranulation triggered by compound 48/80. It significantly inhibited dextran-induced rat paw edema. EH A001 prevented eosinophil accumulation and eosinophil peroxidase activity and reduced the protein content in bronchoalveolar lavage fluid (BALF) in a 'mild' model of asthma. Moreover, the CD4/CD8 ratio in peripheral blood was suppressed. EH A001 attenuated the release of interleukin-4 (IL-4) and augmented interferon-gamma (IFN-gamma) in ovalbumin-sensitized mouse splenocytes. The results were compared with the effects of known compounds, ketotifen, cetirizine and cyclophosphamide. These findings demonstrated that Euphorbia hirta possessed significant activity to prevent early and late phase allergic reactions.

Neuro-muscular biopsy in Churg-Strauss syndrome: 24 cases

Churg-Strauss syndrome (CSS) is a distinctive clinical entity in which systemic vasculitis, associated with eosinophilia, occurs almost exclusively in individuals with adult-onset asthma. The major complications of the condition result from damage to the lungs, heart, and peripheral nerves. Necrotizing vasculitis with eosinophils in the cellular infiltrate, vascular or perivascular infiltration by eosinophils in absence of vessel wall necrosis, extra-vascular eosinophil infiltrates, and vascular or extra-vascular granuloma are histopathological features supportive of CSS. As the peripheral nerve disease often dominates the clinical picture, the peripheral nerve biopsy may be decisive in establishing the diagnosis. In this retrospective study of neuro-muscular biopsies in 24 CSS cases, the authors give an extensive description of neuropathological lesions associated with this disorder. Fifteen patients (62.5%) exhibited eosinophils either in extra-vascular infiltrates or in vessel walls, and 6 of them (25%) had an associated necrotizing vasculitis. Granulomas were found in only 3 cases (12.5%). The clinical diagnosis of CSS was supported in 15 out of the 24 patients (62.5%), in the nerve in 2 cases (8.3%), in the muscle in 8 cases (33.3%), and in both nerve and muscle in 5 others (20.8%).

Aspirin sensitivity and severity of asthma: Evidence for irreversible airway obstruction in patients with severe or difficult-to-treat asthma

BACKGROUND

Patients with aspirin sensitivity experience hyperplastic sinusitis and nasal polyposis. We speculated that similar mechanisms could be acting in the lower airway and that these individuals would demonstrate more severe asthma and irreversible loss of lung function.

OBJECTIVE

We sought to investigate the role of aspirin-exacerbated respiratory disease (AERD) as a risk factor for the development of irreversible airway obstruction.

METHODS

The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study is a multicenter observational study of subjects with severe or difficult-to-treat asthma. Data were compared between subjects who reported asthma exacerbation after aspirin ingestion and those who did not. The primary measure of bronchodilator-resistant obstruction (possible remodeling) was the maximally achieved postbronchodilator spirometry averaged over the 3-year duration of the study.

RESULTS

Adult subjects (>/=18 years) with AERD (n = 459) were compared with subjects with non-aspirin-sensitive asthma (n = 2848). Subjects with AERD had significantly lower mean postbronchodilator percent predicted FEV(1) compared with subjects with non-aspirin-sensitive asthma (75.3% vs 79.9%, P < .001). Differences in spirometry between the 2 cohorts persisted after controlling for potential confounding variables. In addition, subjects with AERD were more likely to have severe asthma by means of physician assessment (66% vs 49%, P < .001), to have been intubated (20% vs 11%, P < .001), to have a steroid burst in the previous 3 months (56% vs 46%, P < .001), and to have required high-dose inhaled corticosteroids (34% vs 26%, P < .001).

CONCLUSIONS

These data suggest that aspirin sensitivity is associated with increased asthma severity and possible remodeling of both the upper and lower airways.

Intratracheal Administration of Bleomycin via a Catheter in Unanesthetized Rats

In order to ensure a widespread distribution in the lung and to avoid the effect of anesthesia, bleomycin at a total dose of 4.5 or 6.0 mg/kg was administered in four divided doses (0.5 ml/kg/time) at intervals of 2 h to male rats via a catheter (tracheotomy tube) without anesthesia. In comparison to vehicle (saline) controls, bleomycin-treated rats showed a significant suppression of body weight gain that was observed transiently at 4.5 mg/kg and continuously (throughout the 3-week observation period) at 6.0 mg/kg. Histopathologically, interstitial pneumonitis, thickening of alveolar walls, thickening of pulmonary arterial walls, foamy cells in alveoli, and hemorrhage were observed in both 4.5 and 6 mg/kg groups, and also emphysema in the 6 mg/kg group. Both groups exhibited a significant decrease in the partial pressure of arterial oxygen (PaO(2)) and a significant increase in alveolar-arterial oxygen tension difference (AaDO(2)), and a significant increase in erythrocyte count was observed in the 6 mg/kg group. Furthermore, both treated groups showed a significant increase in the ratio of the right ventricular weight versus left ventricle plus septum weights. The significant increase in erythrocyte count might have been caused by diffusion disturbance and ventilation-perfusion imbalance due to the pulmonary damage. These findings suggest that the present experimental method will be useful for clarification of the pulmonary damage induced by bleomycin in rats.