RNA Sequencing of Epithelial Cell/Fibroblastic Foci Sandwich in Idiopathic Pulmonary Fibrosis: New Insights on the Signaling Pathway.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by irreversible scarring of the distal lung. IPF is best described by its histopathological pattern of usual interstitial pneumonia (UIP), characterized by spatial heterogeneity with alternating interstitial fibrosis and areas of normal lung, and temporal heterogeneity of fibrosis characterized by scattered fibroblastic foci (FF), dense acellular collagen and honeycomb changes. FF, comprising aggregated fibroblasts/myofibroblasts surrounded by metaplastic epithelial cells (EC), are the cardinal pathological lesion and their presence strongly correlates with disease progression and mortality. We hypothesized that the EC/FF sandwich from patients with UIP/IPF has a distinct molecular signature which could offer new insights into the crosstalk of these two crucial actors in the disease. Laser capture microdissection with RNAseq was used to investigate the transcriptome of the EC/FF sandwich from IPF patients versus controls (primary spontaneous pneumothorax). Differentially expressed gene analysis identified 23 up-regulated genes mainly related to epithelial dysfunction. Gene ontology analysis highlighted the activation of different pathways, mainly related to EC, immune response and programmed cell death. This study provides novel insights into the IPF pathogenetic pathways and suggests that targeting some of these up-regulated pathways (particularly those related to secreto-protein/mucin dysfunction) may be beneficial in IPF. Further studies in a larger number of lung samples, ideally from patients with early and advanced disease, are needed to validate these findings.

Chronic lung allograft pathology lesions in two rat strain combinations.

BACKGROUND: Chronic lung allograft dysfunction remains an obstacle to long-term survival after lung transplantation. Two phenotypes have been described: obliterative bronchiolitis and restrictive allograft syndrome. Preclinical models are essential to analyze chronic lung allograft dysfunction pathophysiology. METHODS: Orthotopic lung transplants from 38 Lewis into Fischer 344 (Lew→F344) and 67 Brown-Norway into Lewis (BN→Lew) rats were performed in our center in the last decade. We carefully reviewed and quantified all grafts with chronic rejection (40 cases) (18 Lew→F344, 22 BN→Lew) with the aim to investigate if histological changes of chronic lung allograft dysfunction could be also detected in rat grafts. RESULTS: All animals showed human reminiscent histological lesions. Early chronic rejection lesions were detected in BN→Lew. End-stage chronic rejection with features of obliterative bronchiolitis was observed in 33% of Lew→F344; end-stage with restrictive allograft syndrome chronic rejection in 67% and 80% of Lew→F344 and BN→Lew, respectively. BN→Lew showed higher grades of endotheliitis, vascular fibrosis, and lower grades of lymphoid aggregates than Lew→F344 (P=0.007, P=0.043, P=0.004, respectively). CONCLUSIONS: Chronic rejection lesions in rat lung allografts mimic those in humans. The frequent occurrence of restrictive allograft syndrome-like lesions in BN→Lew may be related to a higher degree of mismatch in this strain combination. These animal models could allow future mechanistic studies to better understand chronic lung allograft dysfunction pathogenesis.

The Diagnostic Yield of the Multidisciplinary Discussion in Patients With COVID-19 Pneumonia.

Purpose: The hypothesis of the study was that a multidisciplinary approach involving experienced specialists in diffuse parenchymal lung disease might improve the diagnosis of patients with COVID-19 pneumonia. Methods: Two pulmonologists, two radiologists, and two pathologists reviewed 27 patients affected by severe COVID-19 pneumonia as the main diagnosis made by non-pulmonologists. To evaluate whether the contribution of specialists, individually and/or in combination, might modify the original diagnosis, a three-step virtual process was planned. The whole lung examination was considered the gold standard for the final diagnosis. The probability of a correct diagnosis was calculated using a model based on generalized estimating equations. The effectiveness of a multidisciplinary diagnosis was obtained by comparing diagnoses made by experienced pulmonologists with those made by non-pulmonologists. Results: In 19% of cases, the diagnosis of COVID-19-related death was mainly incorrect. The probability of a correct diagnosis increased strikingly from an undedicated clinician to an expert specialist. Every single specialist made significantly more correct diagnoses than any non-pulmonologist. The highest level of accuracy was achieved by the combination of 3 expert specialists (p = 0.0003). Conclusion: The dynamic interaction between expert specialists may significantly improve the diagnostic confidence and management of patients with COVID-19 pneumonia.

Are There New Biomarkers in Tissue and Liquid Biopsies for the Early Detection of Non-Small Cell Lung Cancer?

Lung cancer is one of the most lethal malignancies worldwide, mainly due to its late diagnoses. The detection of molecular markers on samples provided from routine bronchoscopy including several liquid-based cytology tests (e.g., bronchoaspirate, bronchoalveolar lavage) and/or on easily obtained specimens such as sputum could represent a new approach to improve the sensitivity in lung cancer diagnoses. Recently growing interest has been reported for "noninvasive" liquid biopsy as a valuable source for molecular profiling. Unfortunately, a biomarker and/or composition of biomarkers capable of detecting early-stage lung cancer has yet to be discovered even if in the last few years there has been, through the use of revolutionary new technologies, an explosion of lung cancer biomarkers. Assay sensitivity and specificity need to be improved particularly when new approaches and/or tools are used. We have focused on the most important markers detected in tissue, and on several cytological specimens and liquid biopsies overall.

Idiopathic Pulmonary Fibrosis and Antifibrotic Treatments: Focus on Experimental Studies.

CONTEXT: - Idiopathic pulmonary fibrosis (IPF) is a progressive fatal disease that up to now has been associated with a poor outcome. Some advances have been made in understanding the multiple interrelated pathogenic pathways underlying IPF. The disease is now believed to result from complex interactions among genetic, epigenetic, transcriptional, posttranscriptional, metabolic, and environmental factors. The discovery and validation of theranostic biomarkers are necessary to enable a more precise and earlier diagnosis of IPF and to improve the prediction of future disease behavior. Two drugs recently approved by the US Food and Drug Administration, pirfenidone and nintedanib, have shown the ability to reduce the progression of the disease, although survival benefits are only minimal and neither drug prevents or reverses the disease. OBJECTIVE: - To provide a critical overview of the main experimental studies carried out for testing the principal effects of pirfenidone and nintedanib on IPF. DATA SOURCES: - Experimental (animal and in vitro) studies concerning both drugs were used. CONCLUSIONS: - Pirfenidone has a longer history of preclinical experimental studies than nintedanib. Many studies have been reported more recently (after 2014) and some of them evaluated the association of both drugs, thus suggesting their combination in future therapeutic approaches. Future investigations focusing on targets at molecular, cellular, and tissue levels are necessary to have a better in-depth knowledge of the properties of these drugs and to explore the potential efficacy of both or other drug combinations.

Absence of Neurofibromin Induces an Oncogenic Metabolic Switch via Mitochondrial ERK-Mediated Phosphorylation of the Chaperone TRAP1.

Mutations in neurofibromin, a Ras GTPase-activating protein, lead to the tumor predisposition syndrome neurofibromatosis type 1. Here, we report that cells lacking neurofibromin exhibit enhanced glycolysis and decreased respiration in a Ras/ERK-dependent way. In the mitochondrial matrix of neurofibromin-deficient cells, a fraction of active ERK1/2 associates with succinate dehydrogenase (SDH) and TRAP1, a chaperone that promotes the accumulation of the oncometabolite succinate by inhibiting SDH. ERK1/2 enhances both formation of this multimeric complex and SDH inhibition. ERK1/2 kinase activity is favored by the interaction with TRAP1, and TRAP1 is, in turn, phosphorylated in an ERK1/2-dependent way. TRAP1 silencing or mutagenesis at the serine residues targeted by ERK1/2 abrogates tumorigenicity, a phenotype that is reverted by addition of a cell-permeable succinate analog. Our findings reveal that Ras/ERK signaling controls the metabolic changes orchestrated by TRAP1 that have a key role in tumor growth and are a promising target for anti-neoplastic strategies.

Idiopathic pulmonary fibrosis: Are any of the morphological-molecular markers useful in clinical management?

Idiopathic pulmonary fibrosis (IPF), the most common form of chronic interstitial lung disease, is a severe progressive fibrotic disorder of unknown aetiology. The disease has a heterogeneous clinical course, with frequent poor prognosis, similar to malignant disease. Correctly diagnosing IPF has become particularly important in view of the availability of more precise therapeutic indications, thus avoiding steroid treatment and allowing new approaches with novel drugs. To date we have limited information about biomarkers predictive of progressive disease and associated complications. Efforts should be made in the future to more appropriately study lung tissue and then to extrapolate the most clinically fitting biomarkers. This approach is already used in routine management of many cancers and provides a potential road map for more appropriate clinical care of IPF. This review will mainly focus on histology and etiopathogenesis highlighting some morphological and molecular features that may influence the overall management of IPF.

MDM2 and HIF1alpha expression levels in different histologic subtypes of malignant pleural mesothelioma: correlation with pathological and clinical data.

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis and limited treatment options. Sarcomatoid/biphasic mesotheliomas are characterized by more aggressive behaviour and a poorer prognosis compared with the epithelioid subtype. To date prognostic and tailored therapeutic biomarkers are lacking. The present study analyzed the expression levels of MDM2 and HIF1alpha in different histologic subtypes from chemonaive MPM patients. Diagnostic biopsies of MPM patients from four Italian cancer centers were centrally collected and analyzed. MDM2 and HIF1alpha expression levels were investigated through immunohistochemistry and RT-qPCR. Pathological assessment of necrosis, inflammation and proliferation index was also performed. Molecular markers, pathological features and clinical characteristics were correlated to overall survival (OS) and progression free survival (PFS). Sixty MPM patients were included in the study (32 epithelioid and 28 non-epithelioid). Higher levels of MDM2 (p < 0.001), HIF1alpha (p = 0.013), necrosis (p = 0.013) and proliferation index (p < 0.001) were seen mainly in sarcomatoid/biphasic subtypes. Higher levels of inflammation were significantly associated with epithelioid subtype (p = 0.044). MDM2 expression levels were correlated with HIF1alpha levels (p = 0.0001), necrosis (p = 0.008) and proliferation index (p = 0.009). Univariate analysis showed a significant correlation of non-epithelioid histology (p = 0.04), high levels of necrosis (p = 0.037) and proliferation index (p = 0.0002) with shorter PFS. Sarcomatoid/biphasic and epithelioid mesotheliomas showed different MDM2 and HIF1alpha expression levels and were characterized by different levels of necrosis, proliferation and inflammation. Further studies are warranted to confirm a prognostic and predictive role of such markers and features.

Higher Risk of Acute Cellular Rejection in Lung Transplant Recipients with Cystic Fibrosis.

BACKGROUND Acute cellular rejection (ACR) affects up to 40% of recipients within the first year after lung transplant (LTx). The aim of this study was to determine the frequency of ACR and associated major risk factors in cystic fibrosis (CF) recipients. Bronchiolitis obliterans syndrome (BOS) and 1-year/long-term survival were also evaluated. MATERIAL AND METHODS ACR was reviewed in 643 scheduled biopsies from 44 CF (Group 1) versus 89 other recipients (Group 2). We performed univariate/multivariate analyses of risk factors for ACR and BOS, and survival analysis. RESULTS Group 1 showed higher ACR frequency, especially for ACR ≥ A2. Multivariable generalized linear models considering both native lung disease and age showed that higher values of ACR index were significantly related to the pretransplant diagnosis of CF. BOS and long-term survival were not influenced by the increased incidence of ACR. Poorer long-term survival was observed in Group 2. CONCLUSIONS CF recipients have a higher ACR risk, which may be due to enhanced immune activation related to a genetic disorder, and younger age.