A fully automated image analysis method to quantify lung fibrosis in the bleomycin-induced rat model

Investigating the role of platelets and platelet-derived transforming growth factor-β in idiopathic pulmonary fibrosis

Transforming growth factor-β1 (TGFβ1) is the key profibrotic cytokine in idiopathic pulmonary fibrosis (IPF), but the primary source of this cytokine in this disease is unknown. Platelets have abundant stores of TGFβ1, although the role of these cells in IPF is ill-defined. In this study, we investigated whether platelets, and specifically platelet-derived TGFβ1, mediate IPF disease progression. Patients with IPF and non-IPF patients were recruited to determine platelet reactivity, and separate cohorts of patients with IPF were followed for mortality. To study whether platelet-derived TGFβ1 modulates pulmonary fibrosis (PF), mice with a targeted deletion of TGFβ1 in megakaryocytes and platelets (TGFβ1fl/fl.PF4-Cre) were used in the well-characterized bleomycin-induced pulmonary fibrosis (PF) animal model. In a discovery cohort, we found significantly higher mortality in patients with IPF who had elevated platelet counts within the normal range. However, our validation cohort did not confirm this observation, despite significantly increased platelets, neutrophils, active TGFβ1, and CCL5, a chemokine produced by inflammatory cells, in the blood, lung, and bronchoalveolar lavage (BAL) of patients with IPF. In vivo, we showed that despite platelets being readily detected within the lungs of bleomycin-treated mice, neither the degree of pulmonary inflammation nor fibrosis was significantly different between TGFβ1fl/fl.PF4-Cre and control mice. Our results demonstrate for the first time that platelet-derived TGFβ1 does not significantly mediate inflammation or fibrosis in a PF animal model. Furthermore, our human studies revealed blood platelet counts do not consistently predict mortality in IPF but other platelet-derived mediators, such as C-C chemokine ligand 5 (CCL5), may promote neutrophil recruitment and human IPF.NEW & NOTEWORTHY Platelets are a rich source of profibrotic TGFβ; however, the role of platelets in idiopathic pulmonary fibrosis (IPF) is unclear. We identified that patients with IPF have significantly more platelets, neutrophils, and active TGFβ in their airways than control patients. Using an animal model of IPF, we demonstrated that platelet-derived TGFβ does not significantly drive lung fibrosis or inflammation. Our findings offer a better understanding of platelets in both human and animal studies of IPF.

Raman microspectroscopy identifies fibrotic tissues in collagen-related disorders via deconvoluted collagen type I spectra

Fibrosis is a consequence of the pathological remodeling of extracellular matrix (ECM) structures in the connective tissue of an organ. It is often caused by chronic inflammation, which over time, progressively leads to an excess deposition of collagen type I (COL I) that replaces healthy tissue structures, in many cases leaving a stiff scar. Increasing fibrosis can lead to organ failure and death; therefore, developing methods that potentially allow real-time monitoring of early onset or progression of fibrosis are highly valuable. In this study, the ECM structures of diseased and healthy human tissue from multiple organs were investigated for the presence of fibrosis using routine histology and marker-independent Raman microspectroscopy and Raman imaging. Spectral deconvolution of COL I Raman spectra allowed the discrimination of fibrotic and non-fibrotic COL I fibers. Statistically significant differences were identified in the amide I region of the spectral subpeak at 1608 cm^-1, which was deemed to be representative for structural changes in COL I fibers in all examined fibrotic tissues. Raman spectroscopy-based methods in combination with this newly discovered spectroscopic biomarker potentially offer a diagnostic approach to non-invasively track and monitor the progression of fibrosis. STATEMENT OF SIGNIFICANCE: Current diagnosis of fibrosis still relies on histopathological examination with invasive biopsy procedures. Although, several non-invasive imaging techniques such as positron emission tomography, single-photon emission computed tomography and second harmonic generation are gradually employed in preclinical or clinical studies, these techniques are limited in spatial resolution and the morphological interpretation highly relies on individual experience and knowledge. In this study, we propose a non-destructive technique, Raman microspectroscopy, to discriminate fibrotic changes of collagen type I based on a molecular biomarker. The changes of the secondary structure of collagen type I can be identified by spectral deconvolution, which potentially can provide an automatic diagnosis for fibrotic tissues in the clinical applicaion.

Lung cancer-kidney cross talk induces kidney injury, interstitial fibrosis, and enhances cisplatin-induced nephrotoxicity

Patients with cancer represent a unique patient population with increased susceptibility to kidney disease. Drug-induced acute kidney injury (AKI) in patients with cancer is a common problem. Cisplatin is a highly effective treatment used in many solid-organ cancers and causes AKI in 30% of patients, increasing the risk of chronic kidney disease development. Most preclinical cisplatin toxicity studies have been completed in mice without cancer. We believe that the physiology of patients with cancer is not adequately represented in preclinical models, and the objective of this study was to determine how lung cancer will alter the nephrotoxicity of cisplatin. A genetically engineered mouse model and a syngeneic xenograft model of lung cancer were used. Mice were divided into the following four groups: 1) noncancer/vehicle, 2) noncancer/cisplatin, 3) cancer/vehicle, and 4) cancer/cisplatin. Mice were administered cisplatin via intraperitoneal injection once a week for 4 wk. Animals were euthanized 72 h following their final cisplatin injection. Mice with lung cancer had increased renal toxicity, injury, and fibrosis following repeated low doses of cisplatin. In addition, lung cancer alone induced kidney injury and fibrosis in the kidney before cisplatin treatment. In conclusion, this is the first study that we are aware of that assesses the impact of cancer on the kidney in conjunction with the nephrotoxicity of cisplatin. We believe that cancer is providing the first hit to the kidney and the subsequent damage from repeated doses of cisplatin becomes unsurmountable, leading to AKI and progression to chronic kidney disease.NEW & NOTEWORTHY Patients with cancer have impaired kidney function and increased susceptibility to nephrotoxic agents. Cisplatin is a commonly used chemotherapeutic with nephrotoxicity as the dose-limiting side effect. Cisplatin nephrotoxicity is almost exclusively studied in mice without cancer. Our current preclinical models do not adequately represent the complexity of patients with cancer. This study demonstrates increased renal toxicity, injury, and fibrosis in mice with lung cancer, which is exacerbated with cisplatin treatment. These results highlight the necessity of using preclinical models that more accurately capture the altered physiology of patients with cancer treated with cisplatin.

Aprepitant exerts anti-fibrotic effect via inhibition of TGF-β/Smad3 pathway in bleomycin-induced pulmonary fibrosis in rats

Bleomycin is a well-recognized antineoplastic drug. However, pulmonary fibrosis (PF) is considered to be the principal drawback that greatly limits its use. Here, we sought to investigate ability of the neurokinin receptor 1 blocker, aprepitant, to prevent PF caused by bleomycin. Male adult Wistar rat groups were given a single intratracheal injection of bleomycin, either alone or in combination with aprepitant therapy for 3 or 14 days. Collagen deposition and a rise in transforming growth factor beta (TGF-β) immunoreactivity in lung tissue serve as evidence of bleomycin-induced PF. The serum levels of lactate dehydrogenase, alkaline phosphatase, and total antioxidant improved after aprepitant therapy.Additionally, it reduced the protein expressions of interferon alpha, tumor necrosis factor alpha, and lung lipid peroxidation. Moreover, aprepitant treatment led to an increase in the antioxidant indices glutathione, glutathione peroxidase, and catalase. Aprepitant is postulated to protect against bleomycin-induced PF by decreasing TGF-β, phosphorylating Smad3, and increasing interleukin 37, an anti-fibrotic cytokine, and G Protein-coupled Receptor Kinase 2. Aprepitant for 14 days considerably exceeded aprepitant for 3 days in terms of improving lung damage and having an anti-fibrotic impact. In conclusion, aprepitant treatment for 14 days may be used as an adjuvant to bleomycin therapy to prevent PF, mostly through inhibiting the TGF-/p-Smad3 fibrotic pathway.

Increased expression and accumulation of GDF15 in IPF extracellular matrix contribute to fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic disease of unmet medical need. It is characterized by formation of scar tissue leading to a progressive and irreversible decline in lung function. IPF is associated with repeated injury, which may alter the composition of the extracellular matrix (ECM). Here, we demonstrate that IPF patient–derived pulmonary ECM drives profibrotic response in normal human lung fibroblasts (NHLF) in a 3D spheroid assay. Next, we reveal distinct alterations in composition of the diseased ECM, identifying potentially novel associations with IPF. Growth differentiation factor 15 (GDF15) was identified among the most significantly upregulated proteins in the IPF lung–derived ECM. In vivo, GDF15 neutralization in a bleomycin-induced lung fibrosis model led to significantly less fibrosis. In vitro, recombinant GDF15 (rGDF15) stimulated α smooth muscle actin (αSMA) expression in NHLF, and this was mediated by the activin receptor-like kinase 5 (ALK5) receptor. Furthermore, in the presence of rGDF15, the migration of NHLF in collagen gel was reduced. In addition, we observed a cell type–dependent effect of GDF15 on the expression of cell senescence markers. Our data suggest that GDF15 mediates lung fibrosis through fibroblast activation and differentiation, implicating a potential direct role of this matrix-associated cytokine in promoting aberrant cell responses in disease.

Fibropreventive and Antifibrotic Effects of Uncaria gambir on Rats with Pulmonary Fibrosis

Pulmonary fibrosis causes scar tissue formation that disrupts the functioning of the lungs. Uncaria gambir (Hunter) Roxb (hereafter gambir)—a plant native to West Sumatra in Indonesia—contains flavonoid (+)-catechin, which has strong antioxidant activity and can be used to combat pulmonary fibrosis. This random in vivo experimental study analyzed the antifibrotic effect of gambir on the lungs of rats with bleomycin-induced fibrosis. The subjects were 10 groups of 10-week-old male rats weighing around 200–250 g. All groups were terminated at the end of the seventh week or on day 50. The lungs were cleaned, and tissues were taken to analyze inflammatory cell counts and TGF-β1 levels using bronchoalveolar lavage (BAL) with ELISA; type I collagen and tissue inhibitor of metalloproteinase 1 (TIMP-1) levels using immunohistochemistry (IHC); and activation of NF-κB using ELISA and Western blot assays. The most severe histopathological characteristic based on the modified Ashcroft score was in the bleomycin group (BG), whereas the mildest was in the 262 mg/kg of the bodyweight antifibrotic gambir-dosed group (AF G262). The results showed a significant difference in the BAL inflammatory cell count (p=0.017; p < 0.05). AF G262 differed most from the other antifibrotic groups in terms of the number of inflammatory cells (0.63), TGF-β1 levels (3.80), and NF-κB levels (0.48), followed by the 131 mg/kg of the bodyweight antifibrotic gambir-dosed group (AF G131), which also differed most from other antifibrotic groups in terms of NF-κB (0.48), TIMP-1 (11.74), and collagen I (14.50) levels. Western blot analysis showed that the fibropreventive and antifibrotic groups had a specific band size of p65, whereas no specific band binding existed in the control group. This study concluded that the administration of AF G262 could improve fibrosis by lysing the extracellular matrix (ECM) in rat lungs.

Autophagy modulation by irbesartan mitigates the pulmonary fibrotic alterations in bleomycin challenged rats: Comparative study with rapamycin

AIMS

In pulmonary fibrosis, autophagy handles the maintenance of alveolar epithelial cells, prevents epithelial-mesenchymal transition (EMT), and controls collagen turnover. The mammalian target of rapamycin (mTOR) and its translational-dependent proteins are essential regulators of autophagy. Irbesartan (IRB) has earlier ameliorative effects in experimental pulmonary fibrosis. The current study aimed to explore therapeutic autophagy-modulated pulmonary fibrotic changes by IRB versus rapamycin (RAPA) in bleomycin (BLM)-challenged rats.

MATERIALS AND METHODS

A single intratracheal BLM dose at day (0), IRB in different doses (10, 20, and 40 mg/kg) or RAPA (2.5 mg/kg) was given daily for 14 continuous days.

KEY FINDINGS

IRB significantly diminished the fibrotic lung scores. Pulmonary levels of transforming growth factor (TGF)-β1 and hydroxyproline exhibited marked attenuation in IRB (40 mg/kg)-treated rats compared to other treated groups. IRB (40 mg/kg) was not significantly different from RAPA. It downregulated the fibrotic lung phosphorylated mammalian target of rapamycin (p-mTOR) levels and augmented lung Unc-51-like autophagy activating kinase 1 (ULK1), LC3-I and LC3-II more than IRB (10 and 20 mg/kg)-treated fibrotic groups.

SIGNIFICANCE

Autophagic effects via the mTOR signalling pathway may play a role in IRB's antifibrotic effects. Consideration of IRB as a therapeutic antifibrotic agent in pulmonary fibrosis needs further experimental and clinical long-term validation, especially in comorbid with primary hypertension, heart failure, and diabetic renal insults.

Inhibition of aberrant tissue remodelling by mesenchymal stromal cells singly coated with soft gels presenting defined chemomechanical cues

The precise understanding and control of microenvironmental cues could be used to optimize the efficacy of cell therapeutics. Here, we show that mesenchymal stromal cells (MSCs) singly coated with a soft conformal gel presenting defined chemomechanical cues promote matrix remodelling by secreting soluble interstitial collagenases in response to the presence of tumour necrosis factor alpha (TNF-α). In mice with fibrotic lung injury, treatment with the coated MSCs maintained normal collagen levels, fibre density and microelasticity in lung tissue, and the continuous presentation of recombinant TNF-α in the gel facilitated the reversal of aberrant tissue remodelling by the cells when inflammation subsided in the host. Gel coatings with predefined chemomechanical cues could be used to tailor cells with specific mechanisms of action for desired therapeutic outcomes.

Classification of Mouse Lung Metastatic Tumor with Deep Learning

Traditionally, pathologists microscopically examine tissue sections to detect pathological lesions; the many slides that must be evaluated impose severe work burdens. Also, diagnostic accuracy varies by pathologist training and experience; better diagnostic tools are required. Given the rapid development of computer vision, automated deep learning is now used to classify microscopic images, including medical images. Here, we used a Inception-v3 deep learning model to detect mouse lung metastatic tumors via whole slide imaging (WSI); we cropped the images to 151 by 151 pixels. The images were divided into training (53.8%) and test (46.2%) sets (21,017 and 18,016 images, respectively). When images from lung tissue containing tumor tissues were evaluated, the model accuracy was 98.76%. When images from normal lung tissue were evaluated, the model accuracy (“no tumor”) was 99.87%. Thus, the deep learning model distinguished metastatic lesions from normal lung tissue. Our approach will allow the rapid and accurate analysis of various tissues.

Intracellular hydroxyproline imprinting following resolution of bleomycin-induced pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with few treatment options. The poor success in developing anti-IPF strategies have impelled researchers to reconsider the importance of choice for animal model and assessment methodologies. Currently, it is still not settled whether the bleomycin-induced lung fibrosis mouse model finally returns to resolution.This study aimed to follow the dynamic fibrotic features of BLM (Bleomycin)-treated mouse lungs with extended durations through a combination of the latest technologies (micro-CT imaging and histological detection of degraded collagens) with traditional methods. In addition, we also applied immunohistochemistry to explore the distribution of all hydroxyproline-containing molecules.As determined by classical biochemical method, total lung hydroxyproline contents reached peak at 4-week after bleomycin injury and maintained a steady high level thereafter until the end of the experiments (16-week). This result seemed to partially contradict with the changes of other fibrosis evaluation parameters, which indicated a gradual degradation of collagens and a recovery of lung aeration post the fibrosis peak. This inconsistency was well reconciled by our data from immunostaining against hydroxyproline and a fluorescent peptide staining against degraded collagen, together showing large amounts of hydroxyproline-rich degraded collagen fragments detained and enriched within the intracellular regions at 10- or 16-week, rather than at 4-week post the BLM-treatment. Hence, our present data not only offer respiratory researchers a new perspective towards the resolution nature of mouse lung fibrosis, but also remind them to be cautious while using hydroxyproline content assay to evaluate the severity of fibrosis.

Evaluating the protective role of Deglycyrrhizinated licorice root supplement on bleomycin induced pulmonary oxidative damage

The goal of this study was to investigate the protective effect of licorice supplements in a rat model of Bleomycin-induced lung oxidative damage over a duration of one month. The rats were randomly divided into six groups (n = 10 per group). Control group; Bleomycin group (B): rats were IP injected with bleomycin 5 mg/kg twice weekly. Licorice group (L): rats received orally 300 mg/kg licorice extract. Bleomycin and a low dose of Licorice group (BLLG): rats received orally 75 mg/kg licorice daily and injected as the B group. Bleomycin and a middle dose of Licorice group (BMLG): rats received orally 150 mg/kg licorice daily and injected as the Bleomycin group. Bleomycin and a high dose of Licorice group (BHLG): rats received orally 300 mg/kg licorice daily and injected as the Bleomycin group. Treatment with Bleomycin induced inflammation and oxidative damage to the lungs expressed in the disturbance of the measured parameters in the blood serum, the lung tissue, and the broncholavage fluid. In addition to the decreased expression of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and catalase (CAT) in the lung tissues. Bleomycin caused deformative changes in the histopathological and cellular examination of the lungs especially in the alveolar cells and the interstitial space. On the other hand, treated the bleomycin group with different doses of licorice supplement activates the antioxidant defense mechanism and attenuates the oxidative damage and damage induced to the lung. In conclusion, Deglycyrrhizinated licorice root supplement provided strong antioxidant and protective effects on Bleomycin-induced lung damage.

Quantitative Image Analysis for Tissue Biomarker Use: A White Paper From the Digital Pathology Association

Tissue biomarkers have been of increasing utility for scientific research, diagnosing disease, and treatment response prediction. There has been a steady shift away from qualitative assessment toward providing more quantitative scores for these biomarkers. The application of quantitative image analysis has thus become an indispensable tool for in-depth tissue biomarker interrogation in these contexts. This white paper reviews current technologies being employed for quantitative image analysis, their application and pitfalls, regulatory framework demands, and guidelines established for promoting their safe adoption in clinical practice.

Comparison of quantitative and qualitative scoring approaches for radiation-induced pulmonary fibrosis as applied to a preliminary investigation into the efficacy of mesenchymal stem cell delivery methods in a rat model

Objectives

Compare a quantitative, algorithm-driven, and qualitative, pathologist-driven, scoring of radiation-induced pulmonary fibrosis (RIPF). And using these scoring models to derive preliminary comparisons on the effects of different mesenchymal stem cell (MSC) administration modalities in reducing RIPF.

Methods

25 rats were randomized into 5 groups: non-irradiated control (CG), irradiated control (CR), intraperitoneally administered granulocyte-macrophage colony stimulating factor or GM-CSF (Drug), intravascularly administered MSC (IV), and intratracheally administered MSC (IT). All groups, except CG, received an 18 Gy conformal dose to the right lung. Drug, IV and IT groups were treated immediately after irradiation. After 24 weeks of observation, rats were euthanized, their lungs excised, fixed and stained with Masson's Trichrome. Samples were anonymized and RIPF was scored qualitatively by a certified pathologist and quantitatively using ImageScope. An analysis of association was conducted, and two binary classifiers trained to validate the integrity of both qualitative and quantitative scoring. Differences between the treatment groups, as assessed by the pathologist score, were then tested by variance component analysis and mixed models for differences in RIPF outcomes.

Results

There is agreement between qualitative and quantitative scoring for RIPF grades from 4 to 7. Both classifiers performed similarly on the testing set (AUC = 0.923) indicating accordance between the qualitative and quantitative scoring. For comparisons between MSC infusion modalities, the Drug group had better outcomes (mean pathologist scoring of 3.96), correlating with significantly better RIPF outcomes than IV [lower by 0.97, p = 0.047, 95% CI = (0.013, 1.918)] and resulting in an improvement over CR [lower by 0.93, p = 0.037, 95% CI = (0.062, 1.800].

Conclusion

Quantitative image analysis may help in the assessment of therapeutic interventions for RIPF and can serve as a scoring surrogate in differentiating between severe and mild cases of RIPF. Preliminary data demonstrate that the use of GM-CSF was best correlated with lower RIPF severity.

Advances in knowledge

Quantitative image analysis can be a viable supplemental system of quality control and triaging in situations where pathologist work hours or resources are limited. The use of different MSC administration methods can result in different degrees of MSC efficacy and study outcomes.

Digital Image Analysis of Picrosirius Red Staining: A Robust Method for Multi-Organ Fibrosis Quantification and Characterization

Current understanding of fibrosis remains incomplete despite the increasing burden of related diseases. Preclinical models are used to dissect the pathogenesis and dynamics of fibrosis, and to evaluate anti-fibrotic therapies. These studies require objective and accurate measurements of fibrosis. Existing histological quantification methods are operator-dependent, organ-specific, and/or need advanced equipment. Therefore, we developed a robust, minimally operator-dependent, and tissue-transposable digital method for fibrosis quantification. The proposed method involves a novel algorithm for more specific and more sensitive detection of collagen fibers stained by picrosirius red (PSR), a computer-assisted segmentation of histological structures, and a new automated morphological classification of fibers according to their compactness. The new algorithm proved more accurate than classical filtering using principal color component (red-green-blue; RGB) for PSR detection. We applied this new method on established mouse models of liver, lung, and kidney fibrosis and demonstrated its validity by evidencing topological collagen accumulation in relevant histological compartments. Our data also showed an overall accumulation of compact fibers concomitant with worsening fibrosis and evidenced topological changes in fiber compactness proper to each model. In conclusion, we describe here a robust digital method for fibrosis analysis allowing accurate quantification, pattern recognition, and multi-organ comparisons useful to understand fibrosis dynamics.

Multimodal lung tumor image recognition algorithm based on integrated convolutional neural network

Lung cancer has become one of the major diseases that seriously threaten human health. Early diagnosis of lung cancer is very important for the quality of lung cancer patients. Researching computer‐assisted systems for lung cancer recognition is one of the effective means to help physicians quickly diagnose lung cancer. Therefore, this paper studies the multimodal recognition algorithm for lung images. This algorithm uses CT images, PET images, and PET/CT images of lung tumors as the experimental objects and uses convolutional neural network to realize lung tumor recognition. Based on the recognition of lung tumors by convolutional neural networks, an integrated convolutional neural network was used to identify lung tumors to improve the recognition accuracy and reduce the training time. The experimental results show that the convolutional neural network can effectively identify the lung tumor images. The number of iterations and batch size in the training process will have an impact on the recognition of lung tumors. The integrated convolutional neural network designed is superior to single convolutional neural network in terms of recognition accuracy and time consumption.

Artificial intelligence identifies inflammation and confirms fibroblast foci as prognostic tissue biomarkers in idiopathic pulmonary fibrosis

A large number of fibroblast foci (FF) predict mortality in idiopathic pulmonary fibrosis (IPF). Other prognostic histological markers have not been identified. Artificial intelligence (AI) offers a possibility to quantitate possible prognostic histological features in IPF. We aimed to test the use of AI in IPF lung tissue samples by quantitating FF, interstitial mononuclear inflammation, and intra-alveolar macrophages with a deep convolutional neural network (CNN). Lung tissue samples of 71 patients with IPF from the FinnishIPF registry were analyzed by an AI model developed in the Aiforia® platform. The model was trained to detect tissue, air spaces, FF, interstitial mononuclear inflammation, and intra-alveolar macrophages with 20 samples. For survival analysis, cut-point values for high and low values of histological parameters were determined with maximally selected rank statistics. Survival was analyzed using the Kaplan-Meier method. A large area of FF predicted poor prognosis in IPF (p = 0.01). High numbers of interstitial mononuclear inflammatory cells and intra-alveolar macrophages were associated with prolonged survival (p = 0.01 and p = 0.01, respectively). Of lung function values, low diffusing capacity for carbon monoxide was connected to a high density of FF (p = 0.03) and a high forced vital capacity of predicted was associated with a high intra-alveolar macrophage density (p = 0.03). The deep CNN detected histological features that are difficult to quantitate manually. Interstitial mononuclear inflammation and intra-alveolar macrophages were novel prognostic histological biomarkers in IPF. Evaluating histological features with AI provides novel information on the prognostic estimation of IPF.

Multiomics of World Trade Center Particulate Matter-induced Persistent Airway Hyperreactivity. Role of Receptor for Advanced Glycation End Products

Pulmonary disease after World Trade Center particulate matter (WTC-PM) exposure is associated with dyslipidemia and the receptor for advanced glycation end products (RAGE); however, the mechanisms are not well understood. We used a murine model and a multiomics assessment to understand the role of RAGE in the pulmonary long-term effects of a single high-intensity exposure to WTC-PM. After 1 month, WTC-PM-exposed wild-type (WT) mice had airway hyperreactivity, whereas RAGE-deficient (Ager^-/-) mice were protected. PM-exposed WT mice also had histologic evidence of airspace disease, whereas Ager^-/- mice remained unchanged. Inflammatory mediators such as G-CSF (granulocyte colony-stimulating factor), IP-10 (IFN-γ-induced protein 10), and KC (keratinocyte chemoattractant) were differentially expressed after WTC-PM exposure. WTC-PM induced α-SMA, DIAPH1 (protein diaphanous homolog 1), RAGE, and significant lung collagen deposition in WT compared with Ager^-/- mice. Compared with WT mice with PM exposure, relative expression of phosphorylated to total CREB (cAMP response element-binding protein) and JNK (c-Jun N-terminal kinase) was significantly increased in the lung of PM-exposed Ager^-/- mice, whereas Akt (protein kinase B) was decreased. Random forests of the refined lung metabolomic profile classified subjects with 92% accuracy; principal component analysis captured 86.7% of the variance in three components and demonstrated prominent subpathway involvement, including known mediators of lung disease such as vitamin B₆ metabolites, sphingolipids, fatty acids, and phosphatidylcholines. Treatment with a partial RAGE antagonist, pioglitazone, yielded similar fold-change expression of metabolites (N₆-carboxymethyllysine, 1-methylnicotinamide, N¹+N⁸-acetylspermidine, and succinylcarnitine [C4-DC]) between WT and Ager^-/- mice exposed to WTC-PM. RAGE can mediate WTC-PM-induced airway hyperreactivity and warrants further investigation.

Cacna1c haploinsufficiency lacks effects on adult hippocampal neurogenesis and volumetric properties of prefrontal cortex and hippocampus in female rats

The cross-disorder risk gene CACNA1C is strongly involved in the etiology of all major neuropsychiatric disorders, with women often being more affected by CACNA1C mutations than men. Human neuroimaging studies provided evidence that CACNA1C variants are associated with anatomical and functional brain alterations, such as decreased prefrontal volumes, microstructural changes in the hippocampus, and reduced hippocampal activity during memory tasks. In mouse models, Cacna1c alterations were repeatedly linked to disorder-like behavioral phenotypes and reduced adult hippocampal neurogenesis, which has been implicated in the pathology of neuropsychiatric disorders. Here, we applied a recently developed rat model and conducted two studies to investigate the effects of partial Cacna1c depletion on adult hippocampal neurogenesis and volumetric properties of the hippocampus and the prefrontal cortex in adult female constitutive heterozygous (Cacna1c^+/-) rats and wildtype (Cacna1c^+/+) littermate controls. In study 1, we analyzed proliferation versus survival of adult-born hippocampal cells based on a 5-bromodeoxyuridine assay ensuring neuronal cell-type specificity through applying an immunofluorescent multiple staining approach. In study 2, we performed a detailed volumetric analysis with high structural resolution of the dorsal hippocampus and the medial prefrontal cortex, including their major substructures. Our results indicate comparable levels of cell proliferation and neuronal survival in Cacna1c^+/- rats and Cacna1c^+/+ controls. Additionally, we found similar volumes of the dorsal hippocampus and the medial prefrontal cortex across major substructures irrespective of genotype, indicating that Cacna1c haploinsufficiency has no prominent effects on these brain features in female rats.

Airway Resistance Caused by Sphingomyelin Synthase 2 Insufficiency in Response to Cigarette Smoke

Sphingomyelin synthase is responsible for the production of sphingomyelin (SGM), the second most abundant phospholipid in mammalian plasma, from ceramide, a major sphingolipid. Knowledge of the effects of cigarette smoke on SGM production is limited. In the present study, we examined the effect of chronic cigarette smoke on sphingomyelin synthase (SGMS) activity and evaluated how the deficiency of Sgms2, one of the two isoforms of mammalian SGMS, impacts pulmonary function. Sgms2-knockout and wild-type control mice were exposed to cigarette smoke for 6 months, and pulmonary function testing was performed. SGMS2-dependent signaling was investigated in these mice and in human monocyte-derived macrophages of nonsmokers and human bronchial epithelial (HBE) cells isolated from healthy nonsmokers and subjects with chronic obstructive pulmonary disease (COPD). Chronic cigarette smoke reduces SGMS activity and Sgms2 gene expression in mouse lungs. Sgms2-deficient mice exhibited enhanced airway and tissue resistance after chronic cigarette smoke exposure, but had similar degrees of emphysema, compared with smoke-exposed wild-type mice. Sgms2-/- mice had greater AKT phosphorylation, peribronchial collagen deposition, and protease activity in their lungs after smoke inhalation. Similarly, we identified reduced SGMS2 expression and enhanced phosphorylation of AKT and protease production in HBE cells isolated from subjects with COPD. Selective inhibition of AKT activity or overexpression of SGMS2 reduced the production of several matrix metalloproteinases in HBE cells and monocyte-derived macrophages. Our study demonstrates that smoke-regulated Sgms2 gene expression influences key COPD features in mice, including airway resistance, AKT signaling, and protease production.

World Trade Center-Cardiorespiratory and Vascular Dysfunction: Assessing the Phenotype and Metabolome of a Murine Particulate Matter Exposure Model

Vascular changes occur early in the development of obstructive airways disease. However, the vascular remodeling and dysfunction due to World Trade Center-Particulate Matter (WTC-PM) exposure are not well described and are therefore the focus of this investigation. C57Bl/6 female mice oropharyngeally aspirated 200 µg of WTC-PM₅₃ or phosphate-buffered saline (PBS) (controls). 24-hours (24-hrs) and 1-Month (1-M) after exposure, echocardiography, micro-positron emission tomography(µ-PET), collagen quantification, lung metabolomics, assessment of antioxidant potential and soluble-receptor for advanced glycation end products (sRAGE) in bronchoalveolar lavage(BAL) and plasma were performed. 24-hrs post-exposure, there was a significant reduction in (1) Pulmonary artery(PA) flow-velocity and pulmonary ejection time(PET) (2) Pulmonary acceleration time(PAT) and PAT/PET, while (3) Aortic ejection time(AET) and velocity time integral(VTI) were increased, and (4) Aortic acceleration time (AAT)/AET, cardiac output and stroke volume were decreased compared to controls. 1-M post-exposure, there was also significant reduction of right ventricular diameter as right ventricle free wall thickness was increased and an increase in tricuspid E, A peaks and an elevated E/A. The pulmonary and cardiac standard uptake value and volume 1-M post-exposure was significantly elevated after PM-exposure. Similarly, α-smooth muscle actin(α-SMA) expression, aortic collagen deposition was elevated 1-M after PM exposure. In assessment of the metabolome, prominent subpathways included advanced glycation end products (AGEs), phosphatidylcholines, sphingolipids, saturated/unsaturated fatty acids, eicosanoids, and phospholipids. BAL superoxide dismutase(SOD), plasma total-antioxidant capacity activity, and sRAGE (BAL and plasma) were elevated after 24-hrs. PM exposure and associated vascular disease are a global health burden. Our study shows persistent WTC-Cardiorespiratory and Vascular Dysfunction (WTC-CaRVD), inflammatory changes and attenuation of antioxidant potential after PM exposure. Early detection of vascular disease is crucial to preventing cardiovascular deaths and future work will focus on further identification of bioactive therapeutic targets.

Orbit Image Analysis: An open-source whole slide image analysis tool

We describe Orbit Image Analysis, an open-source whole slide image analysis tool. The tool consists of a generic tile-processing engine which allows the execution of various image analysis algorithms provided by either Orbit itself or from other open-source platforms using a tile-based map-reduce execution framework. Orbit Image Analysis is capable of sophisticated whole slide imaging analyses due to several key features. First, Orbit has machine-learning capabilities. This deep learning segmentation can be integrated with complex object detection for analysis of intricate tissues. In addition, Orbit can run locally as standalone or connect to the open-source image server OMERO. Another important characteristic is its scale-out functionality, using the Apache Spark framework for distributed computing. In this paper, we describe the use of Orbit in three different real-world applications: quantification of idiopathic lung fibrosis, nerve fibre density quantification, and glomeruli detection in the kidney.

Oral Administration of Chitosan Attenuates Bleomycin-induced Pulmonary Fibrosis in Rats

BACKGROUND/AIM

Idiopathic pulmonary fibrosis (PF) is a fatal disorder of unknown aetiology with limited treatment options. Chitosan has antibacterial, antifungal, antioxidant, antitumour, and anti-inflammatory effects. This study aimed to investigate the effects of chitosan administration on bleomycin (BLM)-induced PF in rats.

MATERIALS AND METHODS

A PF rat model was established by endotracheal instillation of 5 mg/kg BLM; then, chitosan was administered in drinking water for 3 weeks. Histology, cell counts, and cytokine responses in the bronchoalveolar lavage fluid (BALF) and weight measurements (body and lung) were analyzed to assess its therapeutic effects.

RESULTS

Chitosan administration tended to reduce transforming growth factor (TGF)-β1 and interferon (IFN)-γ levels in BALF, and histopathological examination confirmed that chitosan attenuated the degree of inflammation and fibrosis in the lung.

CONCLUSION

This study revealed that oral chitosan exhibits potential antifibrotic effects, as measured by decreased proinflammatory cytokine levels and histological evaluation, in a BLM-induced PF rat model.

Orbit image analysis machine learning software can be used for the histological quantification of acute ischemic stroke blood clots

Our aim was to assess the utility of a novel machine learning software (Orbit Image Analysis) in the histological quantification of acute ischemic stroke (AIS) clots. We analyzed 50 AIS blood clots retrieved using mechanical thrombectomy procedures. Following H&E staining, quantification of clot components was performed by two different methods: a pathologist using a reference standard method (Adobe Photoshop CC) and an experienced researcher using Orbit Image Analysis. Following quantification, the clots were categorized into 3 types: RBC dominant (≥60% RBCs), Mixed and Fibrin dominant (≥60% Fibrin). Correlations between clot composition and Hounsfield Units density on Computed Tomography (CT) were assessed. There was a significant correlation between the components of clots as quantified by the Orbit Image Analysis algorithm and the reference standard approach (ρ = 0.944**, p < 0.001, n = 150). A significant relationship was found between clot composition (RBC-Rich, Mixed, Fibrin-Rich) and the presence of a Hyperdense artery sign using the algorithmic method (X2(2) = 6.712, p = 0.035*) but not using the reference standard method (X2(2) = 3.924, p = 0.141). Orbit Image Analysis machine learning software can be used for the histological quantification of AIS clots, reproducibly generating composition analyses similar to current reference standard methods.

18F-AzaFol for Detection of Folate Receptor-β Positive Macrophages in Experimental Interstitial Lung Disease-A Proof-of-Concept Study

Background: Interstitial lung disease (ILD) is a common and severe complication in rheumatic diseases. Folate receptor-β is expressed on activated, but not resting macrophages which play a key role in dysregulated tissue repair including ILD. We therefore aimed to pre-clinically evaluate the potential of 18F-AzaFol-based PET/CT (positron emission computed tomography/computed tomography) for the specific detection of macrophage-driven pathophysiologic processes in experimental ILD. Methods: The pulmonary expression of folate receptor-β was analyzed in patients with different subtypes of ILD as well as in bleomycin (BLM)-treated mice and respective controls using immunohistochemistry. PET/CT was performed at days 3, 7, and 14 after BLM instillation using the 18F-based folate radiotracer 18F-AzaFol. The specific pulmonary accumulation of the radiotracer was assessed by ex vivo PET/CT scans and quantified by ex vivo biodistribution studies. Results: Folate receptor-β expression was 3- to 4-fold increased in patients with fibrotic ILD, including idiopathic pulmonary fibrosis and connective tissue disease-related ILD, and significantly correlated with the degree of lung remodeling. A similar increase in the expression of folate receptor-β was observed in experimental lung fibrosis, where it also correlated with disease extent. In the mouse model of BLM-induced ILD, pulmonary accumulation of 18F-AzaFol reflected macrophage-related disease development with good correlation of folate receptor-β positivity with radiotracer uptake. In the ex vivo imaging and biodistribution studies, the maximum lung accumulation was observed at day 7 with a mean accumulation of 1.01 ± 0.30% injected activity/lung in BLM-treated vs. control animals (0.31 ± 0.06% % injected activity/lung; p < 0.01). Conclusion: Our preclinical proof-of-concept study demonstrated the potential of 18F-AzaFol as a novel imaging tool for the visualization of macrophage-driven fibrotic lung diseases.

The miRFIB-Score: A Serological miRNA-Based Scoring Algorithm for the Diagnosis of Significant Liver Fibrosis

Background: The current diagnosis of early-stage liver fibrosis often relies on a serological or imaging-based evaluation of the stage of fibrosis, sometimes followed by an invasive liver biopsy procedure. Novel non-invasive experimental diagnostic tools are often based on markers of hepatocyte damage, or changes in liver stiffness and architecture, which are late-stage characteristics of fibrosis progression, making them unsuitable for the diagnosis of early-stage liver fibrosis. miRNAs control hepatic stellate cell (HSC) activation and are proposed as relevant diagnostic markers. Methods: We investigated the possibility of circulating miRNAs, which we found to be dysregulated upon HSC activation, to mark the presence of significant liver fibrosis (F ≥ 2) in patients with chronic alcohol abuse, chronic viral infection (HBV/HCV), and non-alcoholic fatty liver disease (NAFLD). Results: miRNA-profiling identified miRNA-451a, miRNA-142-5p, Let-7f-5p, and miRNA-378a-3p to be significantly dysregulated upon in vitro HSC activation, and to be highly enriched in their extracellular vesicles, suggesting their potential use as biomarkers. Analysis of the plasma of patients with significant liver fibrosis (F ≥ 2) and no or mild fibrosis (F = 0–1), using miRNA-122-5p and miRNA-29a-3p as positive control, found miRNA-451a, miRNA-142-5p, and Let-7f-5p, but not miRNA-378a-3p, able to distinguish between the two patient populations. Using logistic regression analysis, combining all five dysregulated circulating miRNAs, we created the miRFIB-score with a predictive value superior to the clinical scores Fibrosis-4 (Fib-4), aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, and AST to platelet ratio index (APRI). The combination of the miRFIB-score with circulating PDGFRβ-levels further increased the predictive capacity for the diagnosis of significant liver fibrosis. Conclusions: The miRFIB- and miRFIB^p-scores are accurate tools for the diagnosis of significant liver fibrosis in a heterogeneous patient population.

Diminished stimulator of interferon genes production with cigarette smoke-exposure contributes to weakened anti-adenovirus vectors response and destruction of lung in chronic obstructive pulmonary disease model

Cigarette smoke (CS) is the primary risk factor for chronic obstructive pulmonary disease (COPD) and dampens antiviral response, which increases viral infections and leads to COPD acute exacerbation (AECOPD). Adenovirus, a nonenveloped DNA virus, is linked with AECOPD, whose DNAs trigger innate immune response via interacting with pattern recognition receptors (PRRs). Stimulator of interferon genes (STING), as a cytosolic DNA sensor, participates in adenovirus-induced interferon β (IFNβ)-dependent antiviral response. STING is involved in various pulmonary diseases, but role of STING in pathogenesis of AECOPD is not well documented. In the present study, we explored relationship between STING and AECOPD induced by recombinant adenovirus vectors (rAdVs) and CS in wild type (WT) and STING-/- mice; and also characterized the inhibition of STING- IFNβ pathway in pulmonary epithelium exposed to cigarette smoke extract (CSE). We found that CS or CSE exposure alone dramatically inhibited STING expression, but not significantly effected IFNβ production. Moreover, CS or CSE-exposed significantly suppressed activation of STING-IFNβ pathway induced by rAdVs and suppressed clearance of rAdVs DNA. Inflammation, fibrosis and emphysema of lung tissues were exaggerated when treated with CS plus rAdVs, which further deteriorate in absences of STING. In A549 cells with knockdown of STING, we also observed enhancing apoptosis related to emphysema, especially CSE and adenovirus vectors in combination. Therefore, STING may play a protective role in preventing the progress of COPD.

Storage of blood clots for histological analysis: How long is too long in saline and paraformaldehyde?

To investigate the composition of blood clots following mechanical thrombectomy, it is essential to ensure optimum storage for highest quality histological and immunofluorescence analysis. We investigated for how long clots can be stored in paraformaldehyde (PFA), saline and heparinised saline before the tissue integrity is compromised. Whole blood and fibrin-rich clot analogues were made under dynamic flow conditions. Clots were stored in 4% PFA, saline or heparinised saline for timepoints ranging from 1 hour to two months. Five µm sections were stained with Martius Scarlet Blue to visualise red blood cells (RBCs), white blood cells (WBCs) and fibrin. Semi-quantitative analysis of the integrity of clot components used a scoring system (0: Poor; 1: Sub-par; 2: High). Quantitative analysis used Orbit Image Analysis software. Autofluorescence was assessed using a relative scale. Clots stored in PFA for up to two months were qualitatively similar to those stored for all shorter periods (median score: 2 per component). Clots stored in saline/heparinised saline for one week showed degradation of RBCs and WBCs, but fibrin remained intact (median score: 1, 1, 2 respectively). Degradation of the samples stored in saline/heparinised saline made accurate quantification using Image Analysis software difficult from 24h. Samples stored in PFA for up to two weeks showed an edging autofluorescence effect, which became more evident with prolonged storage. For optimum histology, ideally clots should not be stored in saline before fixation and should ideally be stored in formalin for less than one month to minimise the impact of autofluorescence on immunofluorescence.

Anti-inflammatory Property of Imperatorin on Alveolar Macrophages and Inflammatory Lung Injury

Imperatorin is one of the furanocoumarin derivatives and exists in many medicinal herbs with anticancer, antiviral, antibacterial, and antihypertensive activities. In this study, we examined the anti-inflammatory effects of imperatorin on inflammation-associated lung diseases. Imperatorin reduced iNOS and COX-2 expression and also IL-6 and TNFα production enhanced by zymosan. Imperatorin also inhibited the signaling pathways of JAK/STAT and NF-κB. Moreover, in vivo study also revealed that zymosan-induced immune cell infiltration, pulmonary fibrosis, and edema were relieved by imperatorin in mice. We found that imperatorin exerts anti-inflammatory effects that are associated with amelioration of lung inflammation, edema, and rapid fibrosis. Studies on alveolar macrophages also reveal that imperatorin reduced the production of pro-inflammatory mediators and cytokines and inhibited pro-inflammatory JAK1/STAT3 and NF-κB signaling pathways. These results indicate that imperatorin may be a potential anti-inflammatory agent for inflammatory-associated lung diseases.

Deep neural network based histological scoring of lung fibrosis and inflammation in the mouse model system

Preclinical studies of novel compounds rely on quantitative readouts from animal models. Frequently employed readouts from histopathological tissue scoring are time consuming, require highly specialized staff and are subject to inherent variability. Recent advances in deep convolutional neural networks (CNN) now allow automating such scoring tasks. Here, we demonstrate this for the case of the Ashcroft fibrosis score and a newly developed inflammation score to characterize fibrotic and inflammatory lung diseases. Sections of lung tissue from mice exhibiting a wide range of fibrotic and inflammatory states were stained with Masson trichrome. Whole slide scans using a 20x objective were acquired and cut into smaller tiles of 512x512 pixels. The tiles were subsequently classified by specialized CNNs, either an "Ashcroft fibrosis CNN" or an "inflammation CNN". For the Ashcroft fibrosis score the CNN was fine-tuned by using 14000 labelled tiles. For the inflammation score the CNN was trained with 3500 labelled tiles. After training, the Ashcroft fibrosis CNN achieved an accuracy of 79.5% and the inflammation CNN an accuracy of 80.0%. An error analysis revealed that misclassifications are almost exclusively with neighboring scores, which reflects the inherent ambiguity of parts of the data. The variability between two experts was found to be larger than the variability between the CNN classifications and the ground truth. The CNN generated Ashcroft score was in very good agreement with the score of a pathologist (r2 = 0.92). Our results demonstrate that costly and time consuming scoring tasks can be automated and standardized with deep learning. New scores such as the inflammation score can be easily developed with the approach presented here.