Bidirectional epithelial-mesenchymal crosstalk provides self-sustaining profibrotic signals in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the prototypic progressive fibrotic lung disease with a median survival of 2 to 4 years. Injury to and/or dysfunction of the alveolar epithelium is strongly implicated in IPF disease initiation, but the factors that determine whether fibrosis progresses rather than normal tissue repair occurs remain poorly understood. We previously demonstrated that zinc finger E-box-binding homeobox 1-mediated epithelial-mesenchymal transition in human alveolar epithelial type II (ATII) cells augments transforming growth factor-ß-induced profibrogenic responses in underlying lung fibroblasts via paracrine signaling. Here, we investigated bidirectional epithelial-mesenchymal crosstalk and its potential to drive fibrosis progression. RNA-Seq of lung fibroblasts exposed to conditioned media from ATII cells undergoing RAS-induced epithelial-mesenchymal transition identified many differentially expressed genes including those involved in cell migration and extracellular matrix regulation. We confirmed that paracrine signaling between RAS-activated ATII cells and fibroblasts augmented fibroblast recruitment and demonstrated that this involved a zinc finger E-box-binding homeobox 1-tissue plasminogen activator axis. In a reciprocal fashion, paracrine signaling from transforming growth factor-ß-activated lung fibroblasts or IPF fibroblasts induced RAS activation in ATII cells, at least partially through the secreted protein acidic and rich in cysteine, which may signal via the epithelial growth factor receptor via epithelial growth factor-like repeats. Together, these data identify that aberrant bidirectional epithelial-mesenchymal crosstalk in IPF drives a chronic feedback loop that maintains a wound-healing phenotype and provides self-sustaining profibrotic signals.

Integrated transcriptomic analysis of human tuberculosis granulomas and a biomimetic model identifies therapeutic targets.

Tuberculosis (TB) is a persistent global pandemic, and standard treatment for it has not changed for 30 years. Mycobacterium tuberculosis (Mtb) has undergone prolonged coevolution with humans, and patients can control Mtb even after extensive infection, demonstrating the fine balance between protective and pathological host responses within infected granulomas. We hypothesized that whole transcriptome analysis of human TB granulomas isolated by laser capture microdissection could identify therapeutic targets, and that comparison with a noninfectious granulomatous disease, sarcoidosis, would identify disease-specific pathological mechanisms. Bioinformatic analysis of RNAseq data identified numerous shared pathways between TB and sarcoidosis lymph nodes, and also specific clusters demonstrating TB results from a dysregulated inflammatory immune response. To translate these insights, we compared 3 primary human cell culture models at the whole transcriptome level and demonstrated that the 3D collagen granuloma model most closely reflected human TB disease. We investigated shared signaling pathways with human disease and identified 12 intracellular enzymes as potential therapeutic targets. Sphingosine kinase 1 inhibition controlled Mtb growth, concurrently reducing intracellular pH in infected monocytes and suppressing inflammatory mediator secretion. Immunohistochemical staining confirmed that sphingosine kinase 1 is expressed in human lung TB granulomas, and therefore represents a host therapeutic target to improve TB outcomes.

Autophagy inhibition-mediated epithelial-mesenchymal transition augments local myofibroblast differentiation in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF), the prototypic progressive fibrotic interstitial lung disease, is thought to be a consequence of repetitive micro-injuries to an ageing, susceptible alveolar epithelium. Ageing is a risk factor for IPF and incidence has been demonstrated to increase with age. Decreased (macro)autophagy with age has been reported extensively in a variety of systems and diseases, including IPF. However, it is undetermined whether the role of faulty autophagy is causal or coincidental in the context of IPF. Here, we report that in alveolar epithelial cells inhibition of autophagy promotes epithelial-mesenchymal transition (EMT), a process implicated in embryonic development, wound healing, cancer metastasis and fibrosis. We further demonstrate that this is attained, at least in part, by increased p62/SQSTM1 expression that promotes p65/RELA mediated-transactivation of an EMT transcription factor, Snail2 (SNAI2), which not only controls EMT but also regulates the production of locally acting profibrogenic mediators. Our data suggest that reduced autophagy induces EMT of alveolar epithelial cells and can contribute to fibrosis via aberrant epithelial-fibroblast crosstalk.

Clinical Course of Motor Deficits from Lumbosacral Radiculopathy Due to Disk Herniation.

BACKGROUND: The clinical course of motor deficits from lumbosacral radiculopathy appears to improve with or without surgery. Strength measurements have been confined to manual muscle testing (MMT) and have not been extensively followed and quantified in prior studies. OBJECTIVE: To determine if motor weakness and patient-reported outcomes related to lumbosacral radiculopathy improve without surgical intervention over the course of 12 months. DESIGN: Prospective observational cohort. SETTING: Outpatient academic spine practice. PARTICIPANTS: Adults with acute radicular weakness due to disk herniation. METHODS: Forty patients with radiculopathy and strength deficit were followed over a 12-month period. Objective strength and performance tests as well as survey-based measurements were collected at baseline and then every 3 months. Patients underwent comprehensive pain management and rehabilitation and/or surgical approaches as determined in coordination with the treating specialist. This study was approved by the institutional review board of Colorado. MAIN OUTCOME MEASUREMENTS: Testing of strength was through MMT, handheld dynamometer, and performance-based testing. Furthermore, visual analog scale, modified Oswestry Disability Index, and 36-Item Short Form Health Survey (SF-36) were used to measure pain and disability outcomes. RESULTS: Of the 40 patients, 33 (82.5%) did not have surgery; 7 (17.5%) had surgery. Twenty-four of the 33 patients (60%) did not undergo surgery and were followed for 12 months (Comprehensive Pain Management and Rehabilitation, Complete [CPM&R-C]), and 9 (22%) did not have surgery and lacked at least one follow-up evaluation (Comprehensive Pain Management and Rehabilitation, Incomplete [CPM&R-I]). No statistically significant differences were found on baseline measures of strength deficits and SF-36 domains between the CPM&R-C, Surgery, and CPM&R-I groups. Pain and disability scores in the Surgery group were significantly higher than in the CPM&R-C at baseline. There were statistically significant improvements in all areas of strength, pain, and function when comparing measurements at the 12-month follow-up to baseline in the CPM&R-C group. CONCLUSIONS: Individuals with motor deficits due to lumbosacral radiculopathy improve over time regardless of treatment choice. Most did not choose surgery, and almost all of these patients regained full strength at 1 year. Strength recovery typically occurred in the first 3 months, but there was ongoing recovery over the course of a year. LEVEL OF EVIDENCE: II.

Paracrine signalling during ZEB1-mediated epithelial-mesenchymal transition augments local myofibroblast differentiation in lung fibrosis.

The contribution of epithelial-mesenchymal transition (EMT) to human lung fibrogenesis is controversial. Here we provide evidence that ZEB1-mediated EMT in human alveolar epithelial type II (ATII) cells contributes to the development of lung fibrosis by paracrine signalling to underlying fibroblasts. Activation of EGFR-RAS-ERK signalling in ATII cells induced EMT via ZEB1. ATII cells had extremely low extracellular matrix gene expression even after induction of EMT, however conditioned media from ATII cells undergoing RAS-induced EMT augmented TGFß-induced profibrogenic responses in lung fibroblasts. This epithelial-mesenchymal crosstalk was controlled by ZEB1 via the expression of tissue plasminogen activator (tPA). In human fibrotic lung tissue, nuclear ZEB1 expression was detected in alveolar epithelium adjacent to sites of extracellular matrix (ECM) deposition, suggesting that ZEB1-mediated paracrine signalling has the potential to contribute to early fibrotic changes in the lung interstitium. Targeting this novel ZEB1 regulatory axis may be a viable strategy for the treatment of pulmonary fibrosis.

Phenotypes of organ involvement in sarcoidosis.

Sarcoidosis is a highly variable, systemic granulomatous disease of hitherto unknown aetiology. The GenPhenReSa (Genotype-Phenotype Relationship in Sarcoidosis) project represents a European multicentre study to investigate the influence of genotype on disease phenotypes in sarcoidosis.The baseline phenotype module of GenPhenReSa comprised 2163 Caucasian patients with sarcoidosis who were phenotyped at 31 study centres according to a standardised protocol.From this module, we found that patients with acute onset were mainly female, young and of Scadding type I or II. Female patients showed a significantly higher frequency of eye and skin involvement, and complained more of fatigue. Based on multidimensional correspondence analysis and subsequent cluster analysis, patients could be clearly stratified into five distinct, yet undescribed, subgroups according to predominant organ involvement: 1) abdominal organ involvement, 2) ocular-cardiac-cutaneous-central nervous system disease involvement, 3) musculoskeletal-cutaneous involvement, 4) pulmonary and intrathoracic lymph node involvement, and 5) extrapulmonary involvement.These five new clinical phenotypes will be useful to recruit homogenous cohorts in future biomedical studies.

CD1b-restricted GEM T cell responses are modulated by Mycobacterium tuberculosis mycolic acid meromycolate chains.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major human pandemic. Germline-encoded mycolyl lipid-reactive (GEM) T cells are donor-unrestricted and recognize CD1b-presented mycobacterial mycolates. However, the molecular requirements governing mycolate antigenicity for the GEM T cell receptor (TCR) remain poorly understood. Here, we demonstrate CD1b expression in TB granulomas and reveal a central role for meromycolate chains in influencing GEM-TCR activity. Meromycolate fine structure influences T cell responses in TB-exposed individuals, and meromycolate alterations modulate functional responses by GEM-TCRs. Computational simulations suggest that meromycolate chain dynamics regulate mycolate head group movement, thereby modulating GEM-TCR activity. Our findings have significant implications for the design of future vaccines that target GEM T cells.

Corticosteroids and infliximab impair the performance of interferon-γ release assays used for diagnosis of latent tuberculosis.

The impact of immunosuppression on interferon-γ release assays and novel cytokine biomarkers of TB infection, mycobacteria-specific IL-2, IP-10 and TNF-α responses was investigated in an ex vivo model. Cytokine responses in standard QuantiFERON-TB Gold in-Tube (QFT-GIT) assays were compared with duplicate assays containing dexamethasone or infliximab. Dexamethasone converted QFT-GIT results from positive to negative in 30% of participants. Antigen-stimulated interferon-γ, IL-2 and TNF-α responses were markedly reduced, but IP-10 responses were preserved. Infliximab caused QFT-GIT result conversion in up to 30% of participants and substantial reductions in all cytokine responses. Therefore, corticosteroids and anti-TNF-α agents significantly impair interferon-γ release assay performance. IP-10 may be a more robust TB biomarker than interferon-γ in patients receiving corticosteroids.

Dissection of the host-pathogen interaction in human tuberculosis using a bioengineered 3-dimensional model.

Cell biology differs between traditional cell culture and 3-dimensional (3-D) systems, and is modulated by the extracellular matrix. Experimentation in 3-D presents challenges, especially with virulent pathogens. Mycobacterium tuberculosis (Mtb) kills more humans than any other infection and is characterised by a spatially organised immune response and extracellular matrix remodelling. We developed a 3-D system incorporating virulent mycobacteria, primary human blood mononuclear cells and collagen-alginate matrix to dissect the host-pathogen interaction. Infection in 3-D led to greater cellular survival and permitted longitudinal analysis over 21 days. Key features of human tuberculosis develop, and extracellular matrix integrity favours the host over the pathogen. We optimised multiparameter readouts to study emerging therapeutic interventions: cytokine supplementation, host-directed therapy and immunoaugmentation. Each intervention modulates the host-pathogen interaction, but has both beneficial and harmful effects. This methodology has wide applicability to investigate infectious, inflammatory and neoplastic diseases and develop novel drug regimes and vaccination approaches.

The safety of new drug treatments for idiopathic pulmonary fibrosis.

INTRODUCTION: The management of idiopathic pulmonary fibrosis (IPF) has been transformed by the recent approval of two anti-fibrotic drugs, nintedanib and pirfenidone. An increasing number of patients with IPF are receiving treatment with these novel therapies, and the risk of adverse events that may be associated with their use must be carefully evaluated. Areas covered: Safety data about nintedanib and pirfenidone is critically evaluated, including data from randomized clinical trials and post-marketing reports. Management strategies to minimize the occurrence of side effects are summarized. Expert opinion: The safety profile of the two anti-fibrotic drugs approved for clinical use in IPF patients appears to be comparable. Data from clinical trials and initial post-marketing surveillance indicate that most of the observed side effects are mild and easily manageable. However, approximately 1/5 of patients may discontinue treatment as a consequence of side effects. Careful patient counselling, and regular follow-up during therapy could reduce the rate of discontinuations. Ongoing post-marketing surveillance may further inform our understanding of the safety profile of these therapies.

Cooled Radiofrequency Ablation of Genicular Nerves for Knee Osteoarthritis Pain: A Protocol for Patient Selection and Case Series.

BACKGROUND: Chronic knee pain from osteoarthritis (OA) is common in the aging and the obese population. Radiofrequency ablation of the genicular nerves has been introduced as a potential surgery-sparing treatment for chronic knee pain from OA, yet only two outcome studies have been published and optimal patient selection for this procedure has not been established. OBJECTIVES: We describe a standardized protocol for selecting patients for cooled radiofrequency ablation (C-RFA) of the genicular nerves, as well as the clinical outcomes of four patients ages 63-65 years. METHODS: The threshold for selection based on diagnostic genicular nerve block was ≥ 80% pain reduction. Following successful block, C-RFA of the genicular nerves was performed. Outcomes included pain, function, analgesic medication use, opioid use, and progression to total knee arthroplasty at a minimum of 6 month follow up. RESULTS: C-RFA of the genicular nerves after using the described selection protocol resulted in > 90% pain reduction, improved function and avoidance of surgery at 6 months in all four cases. All opioid and analgesic medication use decreased or was unchanged in all cases. No serious adverse events occurred. CONCLUSIONS: The accompanying case series suggests that this protocol is deserving of randomized, prospective study.

Tuberculosis and TNF-inhibitors: history of exposure should outweigh investigations.

A 39-year-old Indian man was diagnosed with ulcerative colitis on colonic biopsy and started on mesalazine, prednisolone and azathioprine. However, the colitis remained active and required antitumour necrosis factor (TNF) treatment with infliximab. Prior to starting infliximab, his chest X-ray was normal and QuantiFERON interferon γ release assay for tuberculosis (TB) was negative. However, his wife had been treated for pulmonary TB 11 years previously when they were cohabiting. On attending for his third dose of infliximab, he was feverish and tachycardic, and was admitted for investigation. Chest X-ray on admission showed changes consistent with miliary TB, and thoracic CT confirmed extensive miliary nodules with supraclavicular and mediastinal lymphadenopathy. Abdominal CT showed multiple mesenteric lymph nodes. Subsequent bronchoalveolar lavage, neck lymph node aspirate and colonic biopsies all cultured Mycobacterium tuberculosis. In retrospect, a clear history of close household TB exposure should have precipitated consideration of TB chemoprophylaxis prior to anti-TNF treatment.

A disintegrin and metalloprotease (ADAM) 33 protein in patients with pulmonary sarcoidosis.

BACKGROUND AND OBJECTIVE: A disintegrin and metalloproteinase (ADAM) 33 is a susceptibility gene associated with inflammatory lung and skin diseases. It is selectively expressed in mesenchymal cells, and its metalloprotease activity has been linked to angiogenesis and tissue remodelling. A soluble form of ADAM33 (sADAM33) has been identified in the bronchoalveolar lavage fluid (BALF) of asthmatic patients, and its levels inversely correlate with lung function. Because of its association with inflammatory lung diseases, it was hypothesized that sADAM33 is elevated in BALF of patients with pulmonary sarcoidosis. METHODS: After removal of Ig using Protein A/G and enrichment using Concanavalin A beads, sADAM33 was identified in BALF by Western blotting. A fluorescence resonance energy transfer peptide cleavage assay was used to assess ADAM33-like activity in BALF. RESULTS: sADAM33 protein in BALF was detected as a 25 kDa fragment, and levels were significantly increased in samples from sarcoid patients when compared to healthy controls (P < 0.05). Levels of sADAM33 were inversely correlated with lung function (FVC%) (P < 0.05) and DL(CO) % predicted (P < 0.01). No difference in sADAM33 enzymatic activity was observed between healthy and sarcoid BALF samples. CONCLUSIONS: Release of sADAM33 is increased in sarcoid and may be associated with abnormal lung function. sADAM33 may be a biomarker of lung tissue inflammation and remodelling in sarcoid.

Talidomida reduz a produçäo de fator de necrose tumoral alfa por macrófago alveolares / Thalidomide reduces tumour necrosis factor alpha production by alveolar macrophages

Acredita-se que a produçäo abundante de fator de necrose tumoral alfa (TNFÓ) por macrófagos alveolares e outras células pode contribuir para o desenvolvimento de dano pulmonar permanente em muitas doenças inflamatórias. Há a necessidade de um agente, sem os efeitos colaterais dos corticosteróides, que possa reduzir a produçäo de TNFÓ pelos macrófagos ativados pela doença. Este estudo avaliou o efeito da talidomida na produçäo de TNFÓ induzida por lipopolissacarídeo (LPS) pelos macrófagos alveolares obtidos de pacientes com tuberculose e outras doenças associadas com a ativaçäo de macrófagos. Macrófagos alveolares obtidos de lavado broncoalveolar de 31 pacientes (tuberculose: 12, sarcoidose: 3, câncer do pulmäo: 5, bronquite crônica: 5, pneumonia: 6) forma estimulados com LPS isoladamente ou com LPS combinado ou com talidomida ou com dexemetasona. TNFÓ associado à célula, analisado por imunocitoquímica ou TNFÓ liberado por macrófagos, avaliado pelo método de ELISA, estavam muito aumentados nas células incubadas com LPS (p<0,05) e ambos estavam diminuidos após a adiçäo de talidomida (p<0,05) ou de dexametasona(p<0,05) atingindo níveis semelhantes aos observados quando os macrófagos eram incubados apenas com meio de cultura. Domesmo modo, a medida do mRNA do TNFÓ, medido pela hibridizaçäo in situ (ISH), aumentava após a incubaçäo com LPS (p<0,05) mas este aumento näo ocorria quando se adicionava talidomida (p<0,05) ou dexametasona (p<0,05). A capacidade da talidomida em reduzir a produçäo de TNFÓ induzida pelo LPS pelos macrófagos alveolares era a mesma tanto nas células de pacientes com tuberculose como dos pacientes com outras doenças. A capacidade da talidomida em reduzir a produçäo de TNFÓ por macrófagos alveolares destes pacientes com pneumopatias em atividade neste experimento sugere que ela, ou seus análogos, possam ter potencial medicamentoso em reduzir a produçäo de TNFÓ na doença clínica