Eirini Vasarmidi

NLRP3 inflammasome expression in idiopathic pulmonary fibrosis and rheumatoid lung.

In this study we investigated the implication of NLRP3 inflammasomes in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and rheumatoid arthritis–usual interstitial pneumonia (RA-UIP). NLRP3 inflammasome activation at baseline and following stimulation with lipopolysaccharide/ATP was evaluated by measuring interleukin (IL)-1β and IL-18 levels released in the bronchoalveolar lavage fluid (BALF) fluid and by cultures of BALF cells. IL-1β and IL-18 levels were significantly elevated in the BALF and BALF macrophage cultures from RA-UIP patients, consistent with pre-existing inflammasome activation in these patients. In contrast, in IPF, BALF levels of IL-1β were significantly less elevated relative to RA-UIP and IL-18 was lower than controls. Furthermore, upon inflammasome stimulation, IPF BALF macrophage cultures failed to upregulate IL-1β and partly IL-18 secretion, in contrast to controls, which showed robust IL-1β and IL-18 upregulation. Interestingly, RA-UIP BALF cell cultures treated with lipopolysaccharide/ATP showed a potent stimulation of IL-18 secretion but not IL-1β, the latter being already elevated in the unstimulated cultures, while examination of the intracellular IL-1β levels in RA-UIP BALF cells upon NLRP3 inflammasome stimulation showed a significant upregulation of IL-1β suggesting the NLRP3 pathway could be further activated. Taken together, our results suggest distinct inflammasome activation profiles between autoimmune and idiopathic lung fibrosis. Distinct NLRP3 inflammasome activation profiles between autoimmune and IPF lung macrophages compared with controls http://ow.ly/UKYlp

Smoking and interstitial lung diseases

For many years has been well known that smoking could cause lung damage. Chronic obstructive pulmonary disease and lung cancer have been the two most common smoking-related lung diseases. In the recent years, attention has also focused on the role of smoking in the development of interstitial lung diseases (ILDs). Indeed, there are three diseases, namely respiratory bronchiolitis-associated ILD, desquamative interstitial pneumonia and pulmonary Langerhans cell histiocytosis, that are currently considered aetiologically linked to smoking and a few others which are more likely to develop in smokers. Here, we aim to focus on the most recent findings regarding the role of smoking in the pathogenesis and clinical behaviour of ILDs. Smoking is implicated in the pathogenesis and clinical behaviour of interstitial lung disease http://ow.ly/PYLcT

MiR-185/AKT and miR-29a/Collagen 1a pathways are activated in IPF BAL cells

MicroRNA signatures of BAL cells and alveolar macrophages are currently lacking in IPF. Here we sought to investigate the expression of fibrosis-related microRNAs in the cellular component of the BAL in IPF. We thus focused on microRNAs previously associated with fibrosis (miR-29a, miR-29b, miR-29c, let-7d, and miR-21) and rapid IPF progression (miR-185, miR-210, miR-302c-3p miR-376c and miR-423-5p). Among the tested microRNAs miR-29a and miR-185 were found significantly downregulated in IPF while miR-302c-3p and miR-376c were not expressed by BAL cells. Importantly, the downregulation of miR-29a inversely correlated with the significantly increased levels of COL1A1 mRNA in IPF BAL cells. Collagen 1 a was found mainly overexpressed in alveolar macrophages and not other cell types of the BAL by immunofluorescence. In view of the downregulation of miR-185, we tested the response of THP-1 macrophages to profibrotic cytokine TGFb and observed the downregulation of miR-185. Conversely, proinflammatory stimulation lead to miR-185 upregulation. Upon examination of the mRNA levels of known miR-185 targets AKT1, DNMT1 and HMGA2, no significant correlations were observed in the BAL cells. However, increased levels of total AKT and AKTser473 phosphorylation were observed in the IPF BAL cells. Furthermore, miR-185 inhibition in THP-1 macrophages resulted in significant increase of AKTser473 phosphorylation. Our study highlights the importance of BAL microRNA signatures in IPF and identifies significant differences in miR-185/AKT and miR-29a/collagen axes in the BAL cells of IPF patients.

Herpes Simplex Virus type-1 infection affects the expression of extracellular matrix components in human nucleus pulposus cells

Intervertebral disc (IVD) degeneration has a complex multifactorial origin and it is tightly associated with changes in the secretion of proteoglycans and collagen of the Nucleus Pulposus (NP) extracellular matrix. Chronic infection by Herpes virus has been previously associated with disc degeneration after detection of Herpes Simplex Virus type-1 (HSV-1) and CMV DNA in human excised disc samples. The aim of the present study was to assess the effect of HSV-1 infection on proteoglycan synthesis employing human Nucleus Pulposus (HNPCs) cells as a model of intervertebral disc degeneration. During lytic HSV-1 infection, a significant reduction of Decorin expression was observed 8 h post infection (h.p.i) which furthered deteriorated at 24 h.p.i. Biglycan was also reduced but only 24 h.p.i. Collagen type II, although demonstrated a downward trend, it was not statistically significant, whereas both Versican and Aggrecan showed a substantial decrease at 24 h.p.i. Hyaluronan production was not significantly affected. In a non-productive HSV-1 infection, a substantial reduction of Decorin, Biglycan, Versican and Aggrecan expression was found, similarly to our findings from the lytic infection. Furthermore, collagen type II expression was completely abolished. HAS1 expression was not affected, whereas HAS 2 and 3 were found to be significantly reduced. These results indicate that HSV-1 infection of human NP cells yields a complex effect on host extracellular cell function. The viral-induced changes in proteoglycan and collagen type II concentration may affect cell-matrix interactions and lead to a dysfunctional intervertebral disc which may trigger or promote the degeneration process.

Investigation of key autophagy-and mitophagy-related proteins and gene expression in BALF cells from patients with IPF and RA-ILD

Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible interstitial lung disease with a poor prognosis and limited therapeutic options. Over the past decade, research efforts have focused on the pathogenetic mechanisms involved in this enigmatic lung disease. Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease often complicated by the development of interstitial lung disease (ILD), leading to high mortality and morbidity. Autophagy is a process regulating the turnover of subcellular components and organelles, and represents a major cellular homeostatic mechanism. Recent evidence suggests a role of autophagy and mitochondrial dysfunction in the development of IPF, focusing on lung fibroblasts and epithelial cells. The aim of this study was to examine the mRNA levels of molecules involved inthe autophagy pathway in bronchoalveolar lavage fluid (BALF)-derived cellsfrom patients with IPF in comparison topatients with RA demonstrating lung involvement (ILD) by RT-qPCR. The significant upregulation of BECLIN1 was observed in patients with RA-ILD compared with those with IPF. Other genes involved in the autophagy pathway were also examined, such as Unc-51 like autophagy activating kinase 1 (ULK1), BCL2 interacting protein 3 (BNIP3) and p62. No differences in the mRNA expression levels of these genes were observed. As regards the selective degradation of mitochondria and mitophagy, similar PTEN-induced putative kinase 1 (PINK1) and PARKIN; E3 ubiquitin ligase (PRKN) expression, as well as PINK1 protein levels, were observed. On the whole, the findings of this study demonstrate an increased expression of BECLIN1 in BALF cells from patients with RA-ILD compared with those from patients with IPF, while similar levels in other key molecules implicating in the autophagy pathway were observed in patients with IPF and RA-ILD.

miR-185 and miR-29a are similarly expressed in the bronchoalveolar lavage cells in IPF and lung cancer but common targets DNMT1 and COL1A1 show disease specific patterns

Idiopathic pulmonary fibrosis (IPF) and lung cancer (LC) constitute two progressively devastating lung diseases with common risk factors including aging and smoking. There is an increasing interest in the investigation of common pathogenic mechanisms between IPF and LC with therapeutic implications. Several oncomirs, microRNAs associated with malignancy, are also linked with IPF. miR-29a and miR-185 downregulation is probably involved both in carcinogenesis and fibrogenesis. We have previously observed miR-29a and miR-185 downregulation in IPF cells from bronchoalveolar lavage (BAL) and in this study we investigated their expression in LC BAL cells. Common targets of miR-29a and miR-185 such as DNA methyltransferase (DNMT)1, DNMT3b, COL1A1, AKT1 and AKT2 were measured. Potential correlations with pulmonary function tests, smoking status and endobronchial findings were investigated. Similar levels of miR-29a and miR-185 were detected in IPF and LC while their common targets AKT1 and DNMT3b were not found to differ, suggesting potential pathogenetic similarities at the level of key epigenetic regulators. By conrast, COL1A1 mRNA levels were increased in IPF suggesting a disease-specific mRNA signature. Notably, DNMT1 was downregulated in the LC group and its expression was further reduced in the presence of increasing malignant burden as it was implied by the endobronchial findings.

Detection of mitochondrial transfer RNA (mt-tRNA) gene mutations in patients with idiopathic pulmonary fibrosis and sarcoidosis

Mitochondrial reactive oxygen species production may lead to tissue injury associated with two respiratory disorders of unknown origin which are shared by common tissue fibrosis, IPF and sarcoidosis. Sequence analysis of 22 mt-tRNA genes and parts of their flanking genes revealed 32 and 45 mutations in 38/40 IPF and 69/85 sarcoidosis patients respectively. 4 novel mutations were identified. 15/32 and 25/45 mutations were exclusively expressed while 12/32 and 17/45 mutations predominantly occurred in IPF and sarcoidosis group respectively, compared to healthy controls. Novel mutation combinations were solely expressed in disease. Hence, a mitochondrial-mediated pathogenic pathway seems to underlie both entities.

Paroxysmal cough and left sacroiliac joint pain in a 50-year-old Caucasian man

A 50-year-old Caucasian man who was a lifelong nonsmoker presented with a 3-year history of paroxysmal dry cough, fatigue, nonspecific myalgias, muscle weakness of the lower extremities and left sacroiliac joint pain. Initially, he was reviewed by a pulmonologist and subsequently he was referred to the Dept of Thoracic Medicine (Heraklion University Hospital, Heraklion, Greece) for further investigation. His medical history was remarkable for the presence of arterial hypertension on treatment with amlodipine and irbesartan. Can you diagnose this patient with pulmonary symptoms, thoracic and laboratory test abnormalities and sacroiliac joint pain? http://ow.ly/LPyy30kaViz

Late Breaking Abstract - Six years experience of Pirfenidone treatment in IPF patients in Crete: Real life data

Introduction: Pirfenidone is an anti-fibrotic agent that slows down disease progression in patients with IPF. Notably, it reduces the risk of all-cause mortality by 48%in this group of patients. Aim: To evaluate the efficacy of Pirfenidone treatment in our group of IPF patients during the last 6 years. Methods: Data from patients on Pirfenidone from 2011 until 2017 were collected at University Hospital of Heraklion. Demographic data, pulmonary function tests results, thoracic computed tomography (CT) scans, and side effects records were used in the current study. Results: Data from 91 IPF patients on Pirfenidone were collected.20 patients (22%) had also emphysema on chest CT scan, while 12 patients(13%) had pulmonary hypertension on echocardiogram. Repeated pulmonary function tests showed no statistically significant difference on FVC% between different time points of measurements. The majority of the patients on Pirfenidone had demonstrated a stability on their lung function(+5%>ΔFVC%>-5%), whereas the patients with clinically significant drop on their FVC(ΔFVC% Regarding side effects of treatment, 18 patients (20%) had presented photosensitivity and 15 patients(16.5%) had presented GI disturbances. Conclusions: The current study verifies the safety of Pirfenidone treatment in IPF and provides evidence of its efficacy in this group of patient, using real life data.