Dysregulation of lncRNA MALAT1 Contributes to Lung Cancer in African Americans by Modulating the Tumor Immune Microenvironment

African American (AA) populations present with notably higher incidence and mortality rates from lung cancer in comparison to other racial groups. Here, we elucidated the contribution of long non-coding RNAs (lncRNAs) in the racial disparities and their potential clinical applications in both diagnosis and therapeutic strategies. AA patients had elevated plasma levels of MALAT1 and PVT1 compared with cancer-free smokers. Incorporating these lncRNAs as plasma biomarkers, along with smoking history, achieved 81% accuracy in diagnosis of lung cancer in AA patients. We observed a rise in MALAT1 expression, correlating with increased levels of monocyte chemoattractant protein-1 (MCP-1) and CD68, CD163, CD206, indicative of tumor-associated macrophages in lung tumors of AA patients. Forced MALAT1 expression led to enhanced growth and invasiveness of lung cancer cells, both in vitro and in vivo, accompanied by elevated levels of MCP-1, CD68, CD163, CD206, and KI67. Mechanistically, MALAT1 acted as a competing endogenous RNA to directly interact with miR-206, subsequently affecting MCP-1 expression and macrophage activity, and enhanced the tumorigenesis. Targeting MALAT1 significantly reduced tumor sizes in animal models. Therefore, dysregulated MALAT1 contributes to lung cancer disparities in AAs by modulating the tumor immune microenvironment through its interaction with miR-206, thereby presenting novel diagnostic and therapeutic targets.

Dysregulation of lncRNA MALAT1 Contributes to Lung Cancer in African Americans by modulating the tumor immune microenvironment

African American (AA) populations present with notably higher incidence and mortality rates from lung cancer in comparison to other racial groups. Here, we elucidate the contribution of long non-coding RNAs (lncRNAs) in the racial disparities and their potential clinical applications in both diagnosis and therapeutic strategies. AA patients had elevated plasma levels of MALAT1 and PVT1 compared with cancer-free smokers. Incorporating these lncRNAs as plasma biomarkers, along with smoking history, achieved 81% accuracy in diagnosis of lung cancer in AA patients. We observed a rise in MALAT1 expression, correlating with increased levels of monocyte chemoattractant protein-1 (MCP-1) and CD68, CD163, CD206, indicative of tumor-associated macrophages in lung tumors of AA patients. Forced MALAT1 expression led to enhanced growth and invasiveness of lung cancer cells, both in vitro and in vivo, accompanied by elevated levels of MCP-1, CD68, CD163, CD206, and KI67. Mechanistically, MALAT1 acted as a competing endogenous RNA to directly interact with miR-206, subsequently affecting MCP-1 expression and macrophage activity, and enhanced the tumorigenesis. Targeting MALAT1 significantly reduced tumor sizes in animal models. Therefore, dysregulated MALAT1 contributes to lung cancer disparities in AAs by modulating the tumor immune microenvironment through its interaction with miR-206, thereby presenting novel diagnostic and therapeutic targets.

Differential Non-Coding RNA Profiles for Lung Cancer Early Detection in African and White Americans

Introduction

Lung cancer leads in cancer-related deaths. Disparities are observed in lung cancer rates, with African Americans (AAs) experiencing disproportionately higher incidence and mortality compared to other ethnic groups. Non-coding RNAs (ncRNAs) play crucial roles in lung tumorigenesis. Our objective was to identify ncRNA biomarkers associated with the racial disparity in lung cancer.

Methods

Using droplet digital PCR, we examined 93 lung-cancer-associated ncRNAs in the plasma and sputum samples from AA and White American (WA) participants, which included 118 patients and 92 cancer-free smokers. Subsequently, we validated our results with a separate cohort comprising 56 cases and 72 controls.

Results

In the AA population, plasma showed differential expression of ten ncRNAs, while sputum revealed four ncRNAs when comparing lung cancer patients to the control group. In the WA population, the plasma displayed eleven ncRNAs, and the sputum had five ncRNAs showing differential expression between the lung cancer patients and the control group. For AAs, we identified a three-ncRNA panel (plasma miRs-147b, 324-3p, 422a) diagnosing lung cancer in AAs with 86% sensitivity and 89% specificity. For WAs, a four-ncRNA panel was developed, comprising sputum miR-34a-5p and plasma miRs-103-3p, 126-3p, 205-5p, achieving 88% sensitivity and 87% specificity. These panels remained effective across different stages and histological types of lung tumors and were validated in the independent cohort.

Conclusions

The ethnicity-related ncRNA signatures have promise as biomarkers to address the racial disparity in lung cancer.

Streptococcus pneumoniae promotes lung cancer development and progression

Streptococcus pneumoniae (SP) is associated with lung cancer, yet its role in the tumorigenesis remains uncertain. Herein we find that SP attaches to lung cancer cells via binding pneumococcal surface protein C (PspC) to platelet-activating factor receptor (PAFR). Interaction between PspC and PAFR stimulates cell proliferation and activates PI3K/AKT and nuclear factor kB (NF-kB) signaling pathways, which trigger a pro-inflammatory response. Lung cancer cells infected with SP form larger tumors in BALB/C mice compared to untreated cells. Mice treated with tobacco carcinogen and SP develop more lung tumors and had shorter survival period than mice treated with the carcinogen alone. Mutating PspC or PAFR abolishes tumor-promoting effects of SP. Overabundance of SP is associated with the survival. SP may play a driving role in lung tumorigenesis by activating PI3K/AKT and NF-kB pathways via binding PspC to PAFR and provide a microbial target for diagnosis and treatment of the disease.

Full-length IL-33 augments pulmonary fibrosis in an ST2- and Th2-independent, non-transcriptomic fashion

Mature IL-33 (MIL33) acting through its receptor, ST2, is known to regulate fibrosis. The precursor, full-length IL-33 (FLIL33), may function differently from MIL33 and independently of ST2. Here we report that genetic deletion of either IL-33 or ST2 attenuates pulmonary fibrosis in the bleomycin model, as does Cre-induced IL-33 deficiency in response to either acute or chronic bleomycin challenge. However, adenovirus-mediated gene delivery of FLIL33, but not MIL33, to the lungs of either wild-type or ST2-deficient mice potentiates the profibrotic effect of bleomycin without inducing a Th2 phenotype. In cultured mouse lung cells, FLIL33 overexpression induces moderate and distinct transcriptomic changes compared with a robust response induced by MIL33, whereas ST2 deletion abrogates the effects of both IL-33 forms. Thus, FLIL33 may contribute to fibrosis in an ST2-independent, Th2-independent, non-transcriptomic fashion, suggesting that pharmacological targeting of both FLIL33 and MIL33 may prove efficacious in patients with pulmonary fibrosis.

Regulator of Cell Cycle Protein (RGCC/RGC-32) Protects against Pulmonary Fibrosis

Some previous studies in tissue fibrosis have suggested a profibrotic contribution from elevated expression of a protein termed either RGCC (regulator of cell cycle) or RGC-32 (response gene to complement 32 protein). Our analysis of public gene expression datasets, by contrast, revealed a consistent decrease in RGCC mRNA levels in association with pulmonary fibrosis. Consistent with this observation, we found that stimulating primary adult human lung fibroblasts with transforming growth factor (TGF)-β in cell cultures elevated collagen expression and simultaneously attenuated RGCC mRNA and protein levels. Moreover, overexpression of RGCC in cultured lung fibroblasts attenuated the stimulating effect of TGF-β on collagen levels. Similar to humans with pulmonary fibrosis, the levels of RGCC were also decreased in vivo in lung tissues of wild-type mice challenged with bleomycin in both acute and chronic models. Mice with constitutive RGCC gene deletion accumulated more collagen in their lungs in response to chronic bleomycin challenge than did wild-type mice. RNA-Seq analyses of lung fibroblasts revealed that RGCC overexpression alone had a modest transcriptomic effect, but in combination with TGF-β stimulation, induced notable transcriptomic changes that negated the effects of TGF-β, including on extracellular matrix-related genes. At the level of intracellular signaling, RGCC overexpression delayed early TGF-β-induced Smad2/3 phosphorylation, elevated the expression of total and phosphorylated antifibrotic mediator STAT1, and attenuated the expression of a profibrotic mediator STAT3. We conclude that RGCC plays a protective role in pulmonary fibrosis and that its decline permits collagen accumulation. Restoration of RGCC expression may have therapeutic potential in pulmonary fibrosis.

Demystifying idiopathic interstitial pneumonia: time for more etiology-focused nomenclature in interstitial lung disease

INTRODUCTION

A major focus of interstitial lung disease (ILD) has centered on disorders termed idiopathic interstitial pneumonias (IIPs) which include, among others, idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, and respiratory bronchiolitis-interstitial lung disease.

AREAS COVERED

We review the radiologic and histologic patterns for the nine disorders classified by multidisciplinary approach as IIP, and describe the remarkable amount of published epidemiologic, translational, and molecular studies demonstrating their associations with numerous yet definitive environmental exposures, occupational exposures, pulmonary diseases, systemic diseases, medication toxicities, and genetic variants.

EXPERT OPINION

In the 21st century, these disorders termed IIPs are rarely idiopathic, but rather are well-described radiologic and histologic patterns of lung injury that are associated with a wide array of diverse etiologies. Accordingly, the idiopathic nomenclature is misleading and confusing, and may also promote a lack of inquisitiveness, suggesting the end rather than the beginning of a thorough diagnostic process to identify ILD etiology and initiate patient-centered management. A shift toward more etiology-focused nomenclature will be beneficial to all, including patients hoping for better life quality and disease outcome, general medicine and pulmonary physicians furthering their ILD knowledge, and expert ILD clinicians and researchers who are advancing the ILD field.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

A comprehensive assessment of environmental exposures and the medical history guides multidisciplinary discussion in interstitial lung disease

BACKGROUND

Multidisciplinary discussion (MDD) is widely recommended for patients with interstitial lung disease (ILD), but published primary data from MDD has been scarce, and factors influencing MDD other than chest computed tomography (CT) and lung histopathology interpretations have not been well-described.

METHODS

Single institution MDD of 179 patients with ILD.

RESULTS

MDD consensus clinical diagnoses included autoimmune-related ILD, chronic hypersensitivity pneumonitis, smoking-related ILD, idiopathic pulmonary fibrosis, medication-induced ILD, occupation-related ILD, unclassifiable ILD, and a few less common pulmonary disorders. In 168 of 179 patients, one or more environmental exposures or pertinent features of the medical history were identified, including recreational/avocational, residential, and occupational exposures, systemic autoimmune disease, malignancy, medication use, and family history. The MDD process demonstrated the importance of comprehensively assessing these exposures and features, beyond merely noting their presence, for rendering consensus clinical diagnoses. Precise, well-defined chest CT and lung histopathology interpretations were rendered at MDD, including usual interstitial pneumonia, nonspecific interstitial pneumonia, and organizing pneumonia, but these interpretations were associated with a variety of MDD consensus clinical diagnoses, demonstrating their nonspecific nature in many instances. In 77 patients in which MDD consensus diagnosis differed from referring diagnosis, assessment of environmental exposures and medical history was found retrospectively to be the most impactful factor.

CONCLUSIONS

A comprehensive assessment of environmental exposures and pertinent features of the medical history guided MDD. In addition to rendering consensus clinical diagnoses, MDD presented clinicians with opportunities to initiate environmental remediation, behavior modification, or medication alteration likely to benefit individual patients with ILD.

SIRT7 deficiency suppresses inflammation, induces EndoMT, and increases vascular permeability in primary pulmonary endothelial cells

Acute lung injury (ALI), a common condition in critically ill patients, has limited treatments and high mortality. Aging is a risk factor for ALI. Sirtuins (SIRTs), central regulators of the aging process, decrease during normal aging and in aging-related diseases. We recently showed decreased SIRT7 expression in lung tissues and fibroblasts from patients with pulmonary fibrosis compared to controls. To gain insight into aging-related mechanisms in ALI, we investigated the effects of SIRT7 depletion on lipopolysaccharide (LPS)-induced inflammatory responses and endothelial barrier permeability in human primary pulmonary endothelial cells. Silencing SIRT7 in pulmonary artery or microvascular endothelial cells attenuated LPS-induced increases in ICAM1, VCAM1, IL8, and IL6 and induced endomesenchymal transition (EndoMT) with decreases in VE-Cadherin and PECAM1 and increases in collagen, alpha-smooth muscle actin, TGFβ receptor 1, and the transcription factor Snail. Loss of endothelial adhesion molecules was accompanied by increased F-actin stress fibers and increased endothelial barrier permeability. Together, these results show that an aging phenotype induced by SIRT7 deficiency promotes EndoMT with impaired inflammatory responses and dysfunction of the lung vascular barrier.

The full-length interleukin-33 (FLIL33)-importin-5 interaction does not regulate nuclear localization of FLIL33 but controls its intracellular degradation

Human mature IL-33 is a member of the IL-1 family and a potent regulator of immunity through its pro-T helper cell 2 activity. Its precursor form, full-length interleukin-33 (FLIL33), is an intranuclear protein in many cell types, including fibroblasts, and its intracellular levels can change in response to stimuli. However, the mechanisms controlling the nuclear localization of FLIL33 or its stability in cells are not understood. Here, we identified importin-5 (IPO5), a member of the importin family of nuclear transport proteins, as an intracellular binding partner of FLIL33. By overexpressing various FLIL33 protein segments and variants in primary human lung fibroblasts and HEK293T cells, we show that FLIL33, but not mature interleukin-33, physically interacts with IPO5 and that this interaction localizes to a cluster of charged amino acids (positions 46-56) but not to an adjacent segment (positions 61-67) in the FLIL33 N-terminal region. siRNA-mediated IPO5 knockdown in cell culture did not affect nuclear localization of FLIL33. However, the IPO5 knockdown significantly decreased the intracellular levels of overexpressed FLIL33, reversed by treatment with the 20S proteasome inhibitor bortezomib. Furthermore, FLIL33 variants deficient in IPO5 binding remained intranuclear and exhibited decreased levels, which were also restored by the bortezomib treatment. These results indicate that the interaction between FLIL33 and IPO5 is localized to a specific segment of the FLIL33 protein, is not required for nuclear localization of FLIL33, and protects FLIL33 from proteasome-dependent degradation.

Treatment outcomes after implementation of an adapted WHO protocol for severe sepsis and septic shock in Haiti

PURPOSE

The World Health Organization (WHO) has developed a simplified algorithm specific to resource-limited settings for the treatment of severe sepsis emphasizing early fluids and antibiotics. However, this protocol's clinical effectiveness is unknown. We describe patient outcomes before and after implementation of an adapted WHO severe sepsis protocol at a community hospital in Haiti.

MATERIALS AND METHODS

Using a before-and-after study design, we retrospectively enrolled 99 adult Emergency Department patients with severe sepsis from January through March 2012. After protocol implementation in January 2014, we compared outcomes to 67 patients with severe sepsis retrospectively enrolled from February to April 2014. We defined sepsis according to the WHO's Integrated Management of Adult Illness guidelines and severe sepsis as sepsis plus organ dysfunction.

RESULTS

After protocol implementation, quantity of fluid administered increased and the physician's differential diagnoses more often included sepsis. Patients were more likely to have follow-up vital signs taken sooner, a radiograph performed, and a lactic acid tested. There were no improvements in mortality, time to fluids or antimicrobials.

CONCLUSIONS

Use of a simplified sepsis protocol based primarily on physiologic parameters allows for substantial improvements in process measures in the care of severely septic patients in a resource-constrained setting.

Sirtuin 7 is decreased in pulmonary fibrosis and regulates the fibrotic phenotype of lung fibroblasts

Pulmonary fibrosis is a severe condition with no cure and limited therapeutic options. A better understanding of its pathophysiology is needed. Recent studies have suggested that pulmonary fibrosis may be driven by accelerated aging-related mechanisms. Sirtuins (SIRTs), particularly SIRT1, SIRT3, and SIRT6, are well-known mediators of aging; however, limited data exist on the contribution of sirtuins to lung fibrosis. We assessed the mRNA and protein levels of all seven known sirtuins in primary lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated interstitial lung disease (SSc-ILD) in comparison with lung fibroblasts from healthy controls. These unbiased tests revealed a tendency for all sirtuins to be expressed at lower levels in fibroblasts from patients compared with controls, but the greatest decrease was observed with SIRT7. Similarly, SIRT7 was decreased in lung tissues of bleomycin-challenged mice. Inhibition of SIRT7 with siRNA in cultured lung fibroblasts resulted in an increase in collagen and α-smooth muscle actin (α-SMA). Reciprocally, overexpression of SIRT7 resulted in lower basal and TGF-β-induced levels of COL1A1, COL1A2, COL3A1, and α-SMA mRNAs, as well as collagen and α-SMA proteins. Induced changes in SIRT7 had no effect on endogenous TGF-β mRNA levels or latent TGF-β activation, but overexpression of SIRT7 reduced the levels of Smad3 mRNA and protein. In conclusion, the decline in SIRT7 in lung fibroblasts has a profibrotic effect, which is mediated by changes in Smad3 levels.

Activation of heat shock response augments fibroblast growth factor-1 expression in wounded lung epithelium

We previously showed that coincident exposure to heat shock (HS; 42°C for 2 h) and TNF-α synergistically induces apoptosis in mouse lung epithelium. We extended this work by analyzing HS effects on human lung epithelial responses to clinically relevant injury. Cotreatment with TNF-α and HS induced little caspase-3 and poly(ADP-ribose) polymerase cleavage in human small airway epithelial cells, A549 cells, and BEAS2B cells. Scratch wound closure rates almost doubled when A549 and BEAS2B cells and air-liquid interface cultures of human bronchial epithelial cells were heat shocked immediately after wounding. Microarray, qRT-PCR, and immunoblotting showed fibroblast growth factor 1 (FGF1) to be synergistically induced by HS and wounding. Enhanced FGF1 expression in HS/wounded A549 was blocked by inhibitors of p38 MAPK (SB203580) or HS factor (HSF)-1 (KNK-437) and in HSF1 knockout BEAS2B cells. PCR demonstrated FGF1 to be expressed from the two most distal promoters in wounded/HS cells. Wound closure in HS A549 and BEAS2B cells was reduced by FGF receptor-1/3 inhibition (SU-5402) or FGF1 depletion. Exogenous FGF1 accelerated A549 wound closure in the absence but not presence of HS. In the presence of exogenous FGF1, HS slowed wound closure, suggesting that it increases FGF1 expression but impairs FGF1-stimulated wound closure. Frozen sections from normal and idiopathic pulmonary fibrosis (IPF) lung were analyzed for FGF1 and HSP70 by immunofluorescence confocal microscopy and qRT-PCR. FGF1 and HSP70 mRNA levels were 7.5- and 5.9-fold higher in IPF than normal lung, and the proteins colocalized to fibroblastic foci in IPF lung. We conclude that HS signaling may have an important impact on gene expression contributing to lung injury, healing, and fibrosis.

Elevated expression of NEU1 sialidase in idiopathic pulmonary fibrosis provokes pulmonary collagen deposition, lymphocytosis, and fibrosis

Idiopathic pulmonary fibrosis (IPF) poses challenges to understanding its underlying cellular and molecular mechanisms and the development of better therapies. Previous studies suggest a pathophysiological role for neuraminidase 1 (NEU1), an enzyme that removes terminal sialic acid from glycoproteins. We observed increased NEU1 expression in epithelial and endothelial cells, as well as fibroblasts, in the lungs of patients with IPF compared with healthy control lungs. Recombinant adenovirus-mediated gene delivery of NEU1 to cultured primary human cells elicited profound changes in cellular phenotypes. Small airway epithelial cell migration was impaired in wounding assays, whereas, in pulmonary microvascular endothelial cells, NEU1 overexpression strongly impacted global gene expression, increased T cell adhesion to endothelial monolayers, and disrupted endothelial capillary-like tube formation. NEU1 overexpression in fibroblasts provoked increased levels of collagen types I and III, substantial changes in global gene expression, and accelerated degradation of matrix metalloproteinase-14. Intratracheal instillation of NEU1 encoding, but not control adenovirus, induced lymphocyte accumulation in bronchoalveolar lavage samples and lung tissues and elevations of pulmonary transforming growth factor-β and collagen. The lymphocytes were predominantly T cells, with CD8(+) cells exceeding CD4(+) cells by nearly twofold. These combined data indicate that elevated NEU1 expression alters functional activities of distinct lung cell types in vitro and recapitulates lymphocytic infiltration and collagen accumulation in vivo, consistent with mechanisms implicated in lung fibrosis.

Pharmacological In Vivo Inhibition of S-Nitrosoglutathione Reductase Attenuates Bleomycin-Induced Inflammation and Fibrosis

Interstitial lung disease (ILD) characterized by pulmonary fibrosis and inflammation poses a substantial biomedical challenge due to often negative disease outcomes combined with the need to develop better, more effective therapies. We assessed the in vivo effect of administration of a pharmacological inhibitor of S-nitrosoglutathione reductase, SPL-334 (4-{[2-[(2-cyanobenzyl)thio]-4-oxothieno[3,2-d]pyrimidin-3(4H)-yl]methyl}benzoic acid), in a mouse model of ILD induced by intratracheal instillation of bleomycin (BLM). Daily i.p. administration of SPL-334 alone at 0.3, 1.0, or 3.0 mg/kg had no effect on animal body weight, appearance, behavior, total and differential bronchoalveolar lavage (BAL) cell counts, or collagen accumulation in the lungs, showing no toxicity of our investigational compound. Similar administration of SPL-334 for 7 days before and for an additional 14 days after BLM instillation resulted in a preventive protective effect on the BLM challenge-induced decline in total body weight and changes in total and differential BAL cellularity. In the therapeutic treatment regimen, SPL-334 was administered at days 7-21 after BLM challenge. Such treatment attenuated the BLM challenge-induced decline in total body weight, changes in total and differential BAL cellularity, and magnitudes of histologic changes and collagen accumulation in the lungs. These changes were accompanied by an attenuation of BLM-induced elevations in pulmonary levels of profibrotic cytokines interleukin-6, monocyte chemoattractant protein-1, and transforming growth factor-β (TGF-β). Experiments in cell cultures of primary normal human lung fibroblast have demonstrated attenuation of TGF-β-induced upregulation in collagen by SPL-334. It was concluded that SPL-334 is a potential therapeutic agent for ILD.

Permanent alveolar collapse is the predominant mechanism in idiopathic pulmonary fibrosis

Alveolar epithelial cell loss and impaired epithelial cell regeneration are currently accepted as central initiating events in idiopathic pulmonary fibrosis (IPF), but subsequent downstream effects remain uncertain. The most accepted downstream effect is aberrant and dysregulated mesenchymal cell proliferation and excess extracellular matrix (ECM) accumulation. However, biochemical and imaging studies have perhaps somewhat surprisingly indicated little increase in total lung collagen and lung tissue, and have rather shown a substantial decrease in lung aeration and lung air volume. Loss of tissue aeration is a consequence of alveolar collapse, which occurs in IPF as a result of apposition and septal incorporation of denuded basal lamina. Permanent alveolar collapse is well-documented following epithelial injury, has the ability to mimic interstitial fibrosis radiologically and histologically, and is a better supported explanation than dysregulated fibroblast proliferation and excess ECM accumulation for the constellation of findings in patients with IPF.

Standardization of CT depiction of cochlear implant insertion depth

BACKGROUND AND PURPOSE

Imaging a cochlear implant with CT is challenging because of implant-induced artifacts, anatomic cochlear variations, and lack of standard terminology for cochlear anatomy. The purposes of this project were to determine whether the cochlear implant tip was more accurately located on oblique CT reformations than on standard images, to review radiology reports for accurate cochlear implant locations, and to assess agreement between an implant surgeon and neuroradiologist by using standardized cochlear anatomy terminology for cochlear implant depth.

MATERIALS AND METHODS

In this retrospective study, a neuroradiologist and an implant surgeon independently viewed temporal bone CT images of 36 ears with cochlear implants. Direct axial images, standard coronal reformations, and oblique reformations parallel to the cochlea were compared to determine implant tip location, which was described by using a proposed standardized quadrant terminology. Implant locations were compared with the initial formal report generated by the original interpreting neuroradiologist.

RESULTS

Thirty-six temporal bones with cochlear implants underwent CT interpretation for implant location. Interobserver agreement was similar when comparing cochlear implant tip location by using a quadrant nomenclature on axial and coronal images and on oblique reformations. Clinical radiology reports all were imprecise and ambiguous in describing the location of the cochlear implant tip.

CONCLUSIONS

Accurate determination of insertion depth of the cochlear implant array can be determined by assessment of the implant tip on axial, coronal, and oblique CT images, but description of the tip location can be inaccurate due to lack of standardized terminology. We propose using a standardized terminology to communicate tip location by using the round window as the zero reference and quadrant numbering to describe cochlear turns. This results in improvement in radiology report accuracy and consistency regarding the cochlear implant insertion depth.

IFN-γ directly controls IL-33 protein level through a STAT1- and LMP2-dependent mechanism

IL-33 contributes to disease processes in association with Th1 and Th2 phenotypes. IL-33 mRNA is rapidly regulated, but the fate of synthesized IL-33 protein is unknown. To understand the interplay among IL-33, IFN-γ, and IL-4 proteins, recombinant replication-deficient adenoviruses were produced and used for dual expression of IL-33 and IFN-γ or IL-33 and IL-4. The effects of such dual gene delivery were compared with the effects of similar expression of each of these cytokines alone. In lung fibroblast culture, co-expression of IL-33 and IFN-γ resulted in suppression of the levels of both proteins, whereas co-expression of IL-33 and IL-4 led to mutual elevation. In vivo, co-expression of IL-33 and IFN-γ in the lungs led to attenuation of IL-33 protein levels. Purified IFN-γ also attenuated IL-33 protein in fibroblast culture, suggesting that IFN-γ controls IL-33 protein degradation. Specific inhibition of caspase-1, -3, and -8 had minimal effect on IFN-γ-driven IL-33 protein down-regulation. Pharmacological inhibition, siRNA-mediated silencing, or gene deficiency of STAT1 potently up-regulated IL-33 protein expression levels and attenuated the down-regulating effect of IFN-γ on IL-33. Stimulation with IFN-γ strongly elevated the levels of the LMP2 proteasome subunit, known for its role in IFN-γ-regulated antigen processing. siRNA-mediated silencing of LMP2 expression abrogated the effect of IFN-γ on IL-33. Thus, IFN-γ, IL-4, and IL-33 are engaged in a complex interplay. The down-regulation of IL-33 protein levels by IFN-γ in pulmonary fibroblasts and in the lungs in vivo occurs through STAT1 and non-canonical use of the LMP2 proteasome subunit in a caspase-independent fashion.

Interleukin-33 potentiates bleomycin-induced lung injury

The mechanisms of interstitial lung disease (ILD) remain incompletely understood, although recent observations have suggested an important contribution by IL-33. Substantial elevations in IL-33 expression were found in the lungs of patients with idiopathic pulmonary fibrosis and scleroderma lung disease, as well as in the bleomycin injury mouse model. Most of the observed IL-33 expression was intracellular and intranuclear, suggesting involvement of the full-length (fl) protein, but not of the proteolytically processed mature IL-33 cytokine. The effects of flIL-33 on mouse lungs were assessed independently and in combination with bleomycin injury, using recombinant adenovirus-mediated gene delivery. Bleomycin-induced changes were not affected by gene deficiency of the IL-33 receptor T1/ST2. Combined flIL-33 expression and bleomycin injury exerted a synergistic effect on pulmonary lymphocyte and collagen accumulation, which could be explained by synergistic regulation of the cytokines transforming growth factor-β, IL-6, monocyte chemotactic protein-1, macrophage inflammatory protein\x{2013}1α, and tumor necrosis factor-α. By contrast, no increase in the levels of the Th2 cytokines IL-4, IL-5, or IL-13 was evident. Moreover, flIL-33 was found to increase the expression of several heat shock proteins (HSPs) significantly, and in particular HSP70, which is known to be associated with ILD. Thus, flIL-33 is a synergistic proinflammatory and profibrotic regulator that acts by stimulating the expression of several non-Th2 cytokines, and activates the expression of HSP70.

Lymphocyte aggregates persist and accumulate in the lungs of patients with idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with no known effective therapy. It is often assumed, but has not been objectively evaluated, that pulmonary inflammation subsides as IPF progresses. The goal of this work was to assess changes in the degree of inflammatory cell infiltration, particularly lymphocytic infiltration, over the duration of illness in IPF.

Methods

Sixteen patients with confirmed IPF were identified in patients whom surgical lung biopsy (SLB) was performed in early disease, and in patients whom lung transplantation was subsequently performed in end stage disease. A numerical scoring system was used to histologically quantify the amount of fibrosis, honeycomb change, fibroblastic foci, and lymphocyte aggregates in each SLB and lung explant tissue sample. Analyses of quantitative scores were performed by comparing paired, matched samples of SLB to lung explant tissue.

Results

Median time [1st, 3rd quartiles] from SLB to lung transplantation was 24 [15, 29] months. Histologic fibrosis and honeycomb change were more pronounced in the explant samples compared with SLB (P < 0.001 and P < 0.01, respectively), and most notably, higher numbers of lymphocyte aggregates were observed in the explant samples compared to SLB (P = 0.013). Immunohistochemical analyses revealed abundant CD3+ (T lymphocyte) and CD20+ (B lymphocyte) cells, but not CD68+ (macrophage) cells, within the aggregates.

Conclusion

Contrary to the frequent assumption, lymphocyte aggregates were present in greater numbers in advanced disease (explant tissue) compared to early disease (surgical lung biopsy). This finding suggests that active cellular inflammation continues in IPF even in severe end stage disease.

Molecular and cellular mechanisms of pulmonary fibrosis

Pulmonary fibrosis is a chronic lung disease characterized by excessive accumulation of extracellular matrix (ECM) and remodeling of the lung architecture. Idiopathic pulmonary fibrosis is considered the most common and severe form of the disease, with a median survival of approximately three years and no proven effective therapy. Despite the fact that effective treatments are absent and the precise mechanisms that drive fibrosis in most patients remain incompletely understood, an extensive body of scientific literature regarding pulmonary fibrosis has accumulated over the past 35 years. In this review, we discuss three broad areas which have been explored that may be responsible for the combination of altered lung fibroblasts, loss of alveolar epithelial cells, and excessive accumulation of ECM: inflammation and immune mechanisms, oxidative stress and oxidative signaling, and procoagulant mechanisms. We discuss each of these processes separately to facilitate clarity, but certainly significant interplay will occur amongst these pathways in patients with this disease.

Full-length IL-33 promotes inflammation but not Th2 response in vivo in an ST2-independent fashion

Expression of IL-33 is elevated in patients with pulmonary diseases, and full-length (not proteolytically processed) IL-33 is the predominant form in the lungs in health and disease. To determine whether activation of IL-33 is needed for functional effects, activities of full-length mouse and mature mouse (mm) forms of IL-33 were compared in vivo. Replication-deficient adenoviral constructs were used for gene delivery. Both isoforms caused pulmonary infiltration of lymphocytes and neutrophils, whereas mm IL-33 also caused pulmonary eosinophilia and goblet cell hyperplasia and increased expression of IL-4, IL-5, IL-13, IL-17, MCP-1, and KC. The different effects were not associated with differential release from IL-33-producing cells or by differences in subcellular distributions of IL-33 isoforms. Germline deficiency of the cell surface receptor chain ST2 abrogated the mm IL-33-induced Th2-associated effects (pulmonary eosinophilia, goblet cell hyperplasia, and increased IL-4 and IL-5), yet the lymphocytic infiltration induced by full-length mouse IL-33 or mm IL-33 was not fully abrogated by the absence of ST2. The similar effects of IL-33 isoforms were associated with comparable regulation of gene expression, notably matrix metalloproteinases 3, 10, and 13. Thus, full-length IL-33 is functionally active in vivo in an ST2-independent fashion, and its effects are partially different from those of mature IL-33. The different effects of these isoforms, particularly the pro-Th2 effects of mature IL-33, are due to differential utilization of the IL-33R chain ST2, whereas their similar effects result from regulation of gene expression.

Diagnosis of lung cancer in individuals with solitary pulmonary nodules by plasma microRNA biomarkers

Background

Making a definitive preoperative diagnosis of solitary pulmonary nodules (SPNs) found by CT has been a clinical challenge. We previously demonstrated that microRNAs (miRNAs) could be used as biomarkers for lung cancer diagnosis. Here we investigate whether plasma microRNAs are useful in identifying lung cancer among individuals with CT-detected SPNs.

Methods

By using quantitative reverse transcriptase PCR analysis, we first determine plasma expressions of five miRNAs in a training set of 32 patients with malignant SPNs, 33 subjects with benign SPNs, and 29 healthy smokers to define a panel of miRNAs that has high diagnostic efficiency for lung cancer. We then validate the miRNA panel in a testing set of 76 patients with malignant SPNs and 80 patients with benign SPNs.

Results

In the training set, miR-21 and miR-210 display higher plasma expression levels, whereas miR-486-5p has lower expression level in patients with malignant SPNs, as compared to subjects with benign SPNs and healthy controls (all P ≤ 0.001). A logistic regression model with the best prediction was built on the basis of miR-21, miR-210, and miR-486-5p. The three miRNAs used in combination produced the area under receiver operating characteristic curve at 0.86 in distinguishing lung tumors from benign SPNs with 75.00% sensitivity and 84.95% specificity. Validation of the miRNA panel in the testing set confirms their diagnostic value that yields significant improvement over any single one.

Conclusions

The plasma miRNAs provide potential circulating biomarkers for noninvasively diagnosing lung cancer among individuals with SPNs, and could be further evaluated in clinical trials.

Survival in pulmonary fibrosis combined with emphysema: likely defined by characteristics of specific patient subpopulations

Authors' Reply to letter from Cottin et al.

Please see related letter http://www.fibrogenesis.com/content/4/1/16

Early detection of lung adenocarcinoma in sputum by a panel of microRNA markers

Adenocarcinoma is the most common type of lung cancer, the leading cause of cancer deaths in the world. Early detection is the key to improve the survival of lung adenocarcinoma patients. We have previously shown that microRNAs (miRNAs) were stably present in sputum and could be applied to diagnosis of lung cancer. The aim of our study was to develop a panel of miRNAs that can be used as highly sensitive and specific sputum markers for early detection of lung adenocarcinoma. Our study contained 3 phases: (i) marker discovery using miRNA profiling on paired normal and tumor lung tissues from 20 patients with lung adenocarcinoma; (ii) marker optimization by real-time reverse transcription-quantitative polymerase chain reaction on sputum of a case-control cohort consisting of 36 cancer patients and 36 health individuals and (iii) validation on an independent set of 64 lung cancer patients and 58 cancer-free subjects. From the surgical tissues, 7 miRNAs with significantly altered expression were identified, of which "4" were overexpressed and "3" were underexpressed in all 20 tumors. On the sputum samples of the case-control cohort, 4 (miR-21, miR-486, miR-375 and miR-200b) of the 7 miRNAs were selected, which in combination produced the best prediction in distinguishing lung adenocarcinoma patients from normal subjects with 80.6% sensitivity and 91.7% specificity. Validation of the marker panel in the independent populations confirmed the sensitivity and specificity that provided a significant improvement over any single one alone. The sputum markers demonstrated the potential of translation to laboratory settings for improving the early detection of lung adenocarcinoma.

Centrilobular emphysema combined with pulmonary fibrosis results in improved survival

Background

We hypothesized that, in patients with pulmonary fibrosis combined with emphysema, clinical characteristics and outcomes may differ from patients with pulmonary fibrosis without emphysema. We identified 102 patients who met established criteria for pulmonary fibrosis. The amount of emphysema (numerical score) and type of emphysema (centrilobular, paraseptal, or mixed) were characterized in each patient. Clinical characteristics, pulmonary function tests and patient survival were analysed.

Results

Based on the numerical emphysema score, patients were classified into those having no emphysema (n = 48), trivial emphysema (n = 26) or advanced emphysema (n = 28). Patients with advanced emphysema had a significantly higher amount of smoking in pack/years than patients with no emphysema or trivial emphysema (P < 0.0001). Median survival [1st, 3rd quartiles] of patients with advanced emphysema was 63 [36, 82] months compared to 29 [18, 49] months in patients without emphysema and 32 [19, 48] months in patients with trivial emphysema (P < 0.001). Median forced vital capacity (FVC) and total lung capacity (TLC) were higher in the advanced emphysema group compared to patients with no emphysema (P < 0.01 and P < 0.001, respectively), whereas median DL_CO did not differ among groups and was overall low. Within the advanced emphysema group (n = 28), further characterization of the type of emphysema was performed and, within these subgroups of patients, survival was 75 [58, 85] months for patients with centrilobular emphysema, 75 [48, 85] months for patients with mixed centrilobular/paraseptal emphysema, and 24 [22, 35] months for patients with paraseptal emphysema (P < 0.01). Patients with advanced paraseptal emphysema had similar survival times to patients without emphysema.

Conclusions

Patients with pulmonary fibrosis combined with advanced centrilobular or mixed emphysema have an improved survival compared with patients with pulmonary fibrosis without emphysema, with trivial emphysema or with advanced paraseptal emphysema.

Alternatively spliced variants of interleukin-4 promote inflammation differentially

IL-4δ2 is a natural splice variant of IL-4 that lacks the region encoded by the second exon. Numerous reports have suggested that the expression levels of IL-4δ2 change in various diseases, especially those with pulmonary involvement, but the in vivo effects of this splice variant have never been studied. Replication-deficient, AdV-mediated gene delivery of mIL-4δ2 to mouse lungs in vivo was used, and the effects compared with similar adenoviral delivery of mIL-4 or with infection with a noncoding NULL viral construct. Overexpression of IL-4δ2 or IL-4 caused pulmonary infiltration by T and B lymphocytes, whereas in contrast to IL-4, IL-4δ2 did not induce eosinophilia or goblet cell hyperplasia. Microarray analysis of global gene expression revealed that IL-4δ2 and IL-4 had differential effects on gene expression. These splice variants also differentially regulated pulmonary levels of the cytokines TNF-α, eotaxin, IL-1α, IFN-γ, and MCP-1, whereas both tended to increase total lung collagen modestly. Pulmonary infiltration by lymphocytes in response to overexpression of IL-4δ2 was attenuated but not abrogated completely by germline deficiency of IL-4Rα or STAT6, whereas deficiency of endogenous IL-4 had no effect. Thus, IL-4δ2 promotes lymphocytic inflammation in vivo (although differentially from IL-4, in part), and the effects of IL-4δ2 are not mediated by endogenous IL-4. Differential targeting of IL-4δ2 and IL-4 may therefore be considered in developing future therapeutic agents.

Splice isoforms of human interleukin-4 are functionally active in mice in vivo

Interleukin-4 (IL-4) acts on cultured cells in a species-specific fashion, although several reports have suggested that human (h) IL-4 may be functionally active in rodents in vivo. The latter finding, if true, would not only offer possibilities for pre-clinical testing of novel hIL-4-targeting therapies in animals, but also suggests new opportunities for mechanistic studies of IL-4 and its receptors. Conventional IL-4 is encoded by four exons, whereas its poorly studied alternatively spliced isoform is encoded by exons 1, 3 and 4 (IL-4δ2). Replication-deficient adenovirus-mediated gene delivery of hIL-4 isoforms (hIL-4 or hIL-4δ2) to mouse lungs caused similar pulmonary infiltration of T and B lymphocytes, but not eosinophils. There were significant differences in the changes of pulmonary cytokine milieu induced by hIL-4 compared with hIL-4δ2, with hIL-4δ2 inducing higher levels of pro-inflammatory (tumour necrosis factor-α, IL-1, and monocyte chemotactic protein-1) and T helper type 1 (IL-12 and interferon-γ) cytokines. There was no elevation in endogenous mouse (m) IL-4 or mIL-4δ2 mRNAs, and germ-line deficiency of mIL-4 did not affect the degree of pulmonary infiltration. When combined with an ovalbumin model of asthma, hIL-4δ2 stimulated a greater accumulation of lymphocytes than did hIL-4. Pulmonary infiltration of lymphocytes induced by expression of hIL-4 or hIL-4δ2 was attenuated, but not completely abrogated, by germ-line deficiency of mIL-4Rα or murine signal transducer and activator of transcription 6, suggesting that these signalling molecules mediate the in vivo effects of hIL-4 isoforms in mice. These findings suggest that splice isoforms of human IL-4 are functionally active in vivo in mice, and partially share the effects of the corresponding species-specific isoforms.

Early detection of squamous cell lung cancer in sputum by a panel of microRNA markers

Squamous cell carcinoma is a common form of lung cancer, the leading cause of cancer deaths in the world. Identifying early stage lung squamous cell carcinoma patients who would benefit most from effective therapies will reduce the mortality. We have previously shown that microRNAs (miRNAs) were stably present in sputum and potentially useful in diagnosis of lung cancer. The objective of this study was to develop a panel of miRNAs that can be used as a sputum-based test for early stage squamous cell carcinoma of the lungs. This study contained three phases: (1) marker discovery by profiling miRNA expression signatures on 15 lung squamous cell carcinoma and matched normal lung tissue samples with GeneChip miRNA Array; (2) marker optimization by real-time quantitative RT-PCR on sputum of a case-control cohort of 48 stage I lung squamous cell carcinoma patients and 48 healthy individuals; and (3) marker validation on an independent set including 67 lung squamous cell carcinoma patients and 55 healthy subjects. On the surgical tissues, six miRNAs were identified, of which three were overexpressed and three were underexpressed in all 15 tumors. On the sputum samples of the case-control cohort, three (miR-205, miR-210 and miR-708) of the six miRNAs were selected, which in combination produced the best prediction in distinguishing lung squamous cell carcinoma patients from normal subjects with 73% sensitivity and 96% specificity. Validation of the marker panel in the independent populations confirmed the sensitivity and specificity that provided a significant improvement over any single one alone. The sputum markers showed the potential to improve the early detection of lung squamous cell carcinomas.

Variable prevalence of pulmonary hypertension in patients with advanced interstitial pneumonia

BACKGROUND

Pulmonary hypertension may occur in patients with interstitial pneumonia and is associated with increased mortality. We sought to determine the prevalence of pulmonary hypertension in sub-groups of patients with interstitial pneumonia and to investigate possible associations between pulmonary vascular hemodynamics and pulmonary function.

METHODS

The presence or absence of pulmonary hypertension was assessed in 70 patients with advanced interstitial pneumonia who underwent right heart catheterization. The associations of pulmonary hypertension with clinical characteristics and pulmonary function tests were analyzed.

RESULTS

The prevalence of pulmonary hypertension in patients with idiopathic interstitial pneumonia was 29% vs 64% in patients with connective tissue disease-interstitial pneumonia (p = 0.013). African American patients had a significantly higher prevalence of pulmonary hypertension in the entire study population (81% vs 22%, p < 0.001) and in the idiopathic interstitial pneumonia group (70% vs 19%, p < 0.01). Regression analyses revealed no association between mean pulmonary artery pressure (mPAP) and forced vital capacity or mPAP and diffusion capacity of the lung for carbon monoxide in the entire cohort or in sub-groups of patients.

CONCLUSIONS

African American patients and patients with connective tissue disease-interstitial pneumonia had a high prevalence of pulmonary hypertension. Non-African American patients with advanced idiopathic interstitial pneumonia (including idiopathic pulmonary fibrosis) had a low prevalence of pulmonary hypertension.

Regulation of pulmonary inflammation and fibrosis through expression of integrins alphaVbeta3 and alphaVbeta5 on pulmonary T lymphocytes

OBJECTIVE

Pulmonary diseases associated with fibrosis, including scleroderma lung disease, are characterized by the accumulation of T cells in the lungs. These cells are thought to facilitate lung fibrosis, but the exact mechanisms of their profibrotic action are not clear. Several alphaV-containing integrins, including alphaVbeta3 and alphaVbeta5, have been shown to directly activate transforming growth factor beta (TGFbeta) and promote collagen accumulation. The aim of this study was to investigate whether pulmonary T cells express profibrotic integrins and regulate collagen accumulation.

METHODS

Expression of integrins was assessed by immunohistochemical analysis of lung tissue, by flow cytometry using bronchoalveolar lavage fluid from patients with systemic sclerosis (SSc), and in a CCL18 overexpression animal model of pulmonary T cell infiltration. Experiments in cell cultures were performed to determine whether integrin-expressing T cells are profibrotic in cocultures with pulmonary fibroblasts and, if so, through what possible mechanism.

RESULTS

Lymphocytes and integrin-positive cells were present in the lungs, and pulmonary T cells expressed integrins alphaVbeta3 and alphaVbeta5 in patients with SSc and in the animal model. Systemic administration of neutralizing anti-integrin alphaV antibody or a genetic deficiency of integrin beta3 in the CCL18 overexpression model significantly attenuated CCL18-driven pulmonary lymphocytic infiltration and collagen accumulation. Jurkat T cells overexpressing integrin alphaVbeta3 or integrin alphaVbeta5 in cocultures with primary pulmonary fibroblasts stimulated collagen accumulation and Smad2 nuclear translocation. Neutralizing anti-TGFbeta antibody attenuated the profibrotic effect of integrin-expressing T cells.

CONCLUSION

Pulmonary infiltrating T lymphocytes may express integrins alphaVbeta3 and alphaVbeta5 that are necessary for lymphocytic infiltration and T cell-associated TGFbeta activation and collagen accumulation.

Altered miRNA expression in sputum for diagnosis of non-small cell lung cancer

Analysis of molecular genetic markers in biological fluids has been proposed as a useful tool for cancer diagnosis. MicroRNAs (miRNAs) are small regulatory RNAs that are frequently dysregulated in lung cancer and have shown promise as tissue-based markers for its prognostication. The aim of this study was to determine whether aberrant miRNA expression can be used as a marker in sputum specimen for the diagnosis of non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

expressions of mature miRNAs, mir-21 and mir-155, were examined by real-time reverse transcription polymerase chain reaction (RT-PCR) and normalized to that of control miRNA, U6B, in sputum of 23 patients with NSCLC and 17 cancer-free subjects. The data was compared with conventional sputum cytology for the diagnosis of lung cancer. All endogenous miRNAs were present in sputum in a remarkably stable form and sensitively and specifically detected by real-time RT-PCR. Mir-21 expression in the sputum specimens was significantly higher in cancer patients (76.32+/-9.79) than cancer-free individuals (62.24+/-3.82) (P<0.0001). Furthermore, overexpression of mir-21 showed highly discriminative receiver-operator characteristic (ROC) curve profile, clearly distinguishing cancer patients from cancer-free subjects with areas under the ROC curve at 0.902+/-0.054. Detection of mir-21 expression produced 69.66% sensitivity and 100.00% specificity in diagnosis of lung cancer, as compared with 47.82% sensitivity and 100.00% specificity by sputum cytology. The measurement of altered miRNA expression in sputum could be a useful noninvasive approach for the diagnosis of lung cancer.

Unique immune regulation by alternatively spliced IL-4 (97.3)

We have previously shown that IL-4δ2, a naturally occurring in humans and other species splice variant of IL-4, competes with IL-4 for receptor binding and inhibits some of IL-4 effects on lymphocytes and monocytes. Numerous groups reported that the levels and the ratio of IL-4δ2 and IL-4 mRNAs change in immune, inflammatory, and infectious diseases. It has been suggested that recombinant human (rh) IL-4δ2 can be used therapeutically to neutralize the harmful effects of excess IL-4 in vivo, although it was not clear whether IL-4δ2 mRNA expressing cells secrete IL-4δ2 protein. Transfection of HEK293 or Jurkat cells with IL-4δ2-encoding constructs resulted in IL-4δ2 protein secretion confirmed by LC/MS, ELISA, and Western blotting. To investigate whether IL-4δ2 has no independent activity and acts only as an inhibitor of IL-4, we overexpressed human IL-4δ2 in mouse lungs. Adenovirus-mediated gene delivery of IL-4δ2 caused lymphocytic infiltration similar to that in IL-4-overexpressing mice, as well as proinflammatory/Th1 changes in pulmonary milieu, with the induced levels of TNF-α, IL-1, IFN-γ, IL-12p40, and MCP-1 significantly exceeding those induced by gene delivery of IL-4. Germline deficiency of STAT6 had no effect, whereas deficiency of IL-4Rα significantly attenuated IL-4δ2-induced or IL-4-induced changes in the lungs. Stimulation of primary human T cells or PBMC, but not fibroblasts or A549 cells, with rhIL-4δ2 induced phosphorylation of Jak1, Jak3, and Tyk2, but not of STAT6. IL-4δ2 potently induced production of MCP-1 in human T cells and upregulated IL-4δ2 mRNA production in an autocrine fashion by several hundred fold. Thus, IL-4δ2 is secreted as a protein, acts as a potent autocrine regulator of inflammation and immunity in an IL-4Rα-dependent STAT6-independent fashion, and is a potential novel target for future therapies.

T cells regulate interstitial lung disease via expression of integrins (95.9)

Interstitial lung disease, a combination of pulmonary inflammation and fibrosis, is deadly and occurs idiopathically or as a complication of autoimmune rheumatic diseases (scleroderma, rheumatoid arthritis, poly- and dermatomyositis, lupus). T cells often accumulate in the lungs of such patients. Previous reports suggested that αV-containing integrins may activate TGF-β and facilitate fibrosis. Whether pulmonary T cells utilize such integrins in interstitial lung disease is not clear. Expression of integrins αVβ3 (ITGAVB3) or αVβ5 (ITGAVB5) on pulmonary T cells was observed by double-stain immunofluorescence confocal microscopy in six out of six patients with scleroderma lung disease, as well as in the animal models of pulmonary CCL18 overexpression that manifests in selective T lymphocytic infiltration of the lungs and T cell-dependent pulmonary fibrosis. Flow cytometry of bronchoalveolar lavage T cells confirmed expression of integrins on more than 10% (up to 50%) of pulmonary T cells in 14 of 25 scleroderma patients and in all CCL18-overexpressing mice; Q-PCR experiments confirmed elevated integrin mRNAs in purified BAL T cells. There was no expression of ITGAVB3 or ITGAVB5 on T cells from the lungs of healthy volunteers or control mice. Injections of anti-ITGB3 blocking antibody or genetic deficiency of ITGB3 protected mice from CC18-induced inflammation and fibrosis. Jurkat cells that were forced to overexpress ITGAVB3 or ITGAVB5 induced Smad2 phosphorylation and nuclear translocation, and increases in collagen and α-smooth muscle actin expression in co-cultures with primary lung fibroblasts. Blocking anti-TGF-β antibodies attenuated such regulation in cell co-cultures. Thus, expression of integrins on pulmonary T cells contributes to interstitial lung disease by promoting T cell infiltration, TGF-β activation, and fibrosis.

Fibrotic footprint of Oncostatin M-induced pulmonary disease (97.10)

Oncostatin M (OSM), an IL-6 family cytokine, has been implicated in a number of biological processes including the induction of inflammation and modulation of extracellular matrix (ECM). Recently, we observed that OSM is elevated in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis as well as scleroderma. In mice, delivery of OSM to the lungs results in recruitment of inflammatory cells and an increase in collagen deposition in the lungs, with pathological correlates to characteristic human interstitial lung disease. We used genetically modified mice to show that the fibrotic response is largely independent of B and T lymphocytes, eosinophils and mast cells. To investigate the relationship between OSM-induced inflammation and OSM-induced fibrosis, we used both protein and genomic array approaches to generate a "fibrotic footprint" for OSM. While the IL-4/IL-13 and TGF-β pathways are generally intertwined in fibrosis, we show that OSM is capable of driving lung fibrosis independent of these pathways. For comparison, we show the expression patterns of OSM versus bleomycin-induced lung fibrosis to highlight the unique mechanisms underlying disease pathogenesis. The demonstration that OSM is a potent mediator of lung inflammation and ECM accumulation, and upregulated in patients, provides a rationale for targeting OSM in human disease.

Aldehyde dehydrogenase 1 is a tumor stem cell-associated marker in lung cancer

Tumor contains small population of cancer stem cells (CSC) that are responsible for its maintenance and relapse. Analysis of these CSCs may lead to effective prognostic and therapeutic strategies for the treatment of cancer patients. We report here the identification of CSCs from human lung cancer cells using Aldefluor assay followed by fluorescence-activated cell sorting analysis. Isolated cancer cells with relatively high aldehyde dehydrogenase 1 (ALDH1) activity display in vitro features of CSCs, including capacities for proliferation, self-renewal, and differentiation, resistance to chemotherapy, and expressing CSC surface marker CD133. In vivo experiments show that the ALDH1-positive cells could generate tumors that recapitulate the heterogeneity of the parental cancer cells. Immunohistochemical analysis of 303 clinical specimens from three independent cohorts of lung cancer patients and controls show that expression of ALDH1 is positively correlated with the stage and grade of lung tumors and related to a poor prognosis for the patients with early-stage lung cancer. ALDH1 is therefore a lung tumor stem cell-associated marker. These findings offer an important new tool for the study of lung CSCs and provide a potential prognostic factor and therapeutic target for treatment of the patients with lung cancer.

Combined genetic analysis of sputum and computed tomography for noninvasive diagnosis of non-small-cell lung cancer

CT plays an important role in diagnosis of lung cancer, however has been limited by uncertain detection rate for early stage of non-small-cell lung cancer (NSCLC), particularly central tumors. Genetic analysis of sputum has proven to be useful in diagnosis of NSCLC. We proposed to evaluate efficacy of combing CT and genetic analysis of sputum for noninvasive diagnosis of stage I NSCLC. Genomic copy changes of a panel of lung cancer-related genes, HYAL2, FHIT, p16, and SP-A were analyzed by a mini-chip in sputum from 33 patients with stage I NSCLC and 49 cancer-free controls. The genetic and CT diagnoses were compared with surgical-pathologic stage. CT had higher sensitivity (85%) in detection of lung cancer compared with the mini-chip (70%) (p<0.05), while there was no significant difference in specificity between the two tests (89% vs. 92%, p=0.09). Similarly, CT showed considerably higher sensitivity (93%) in identifying peripheral tumors than did the mini-chip (64%) (p<0.05), whereas there was no difference in specificity between them (98% vs. 96%, p=0.28). However, in detecting central tumors, CT had lower specificity (90%) compared with the mini-chip (98%) (p<0.05), although its sensitivity (79%) was higher than that of the mini-chip (73%) (p=0.05). Combining both tests offered higher sensitivity (91%) than did any single one (85%, 70%, all <0.05), while still keeping 92% sensitivity. In particular, this combined approach yielded higher sensitivity, specificity, and accuracy for diagnosing central cancers compared with CT alone (all p<0.05). The integration of the genetic assay with CT led to improvements in noninvasive diagnosis of stage I NSCLCs, especially central tumors.

Mechanisms of oncostatin M-induced pulmonary inflammation and fibrosis

Oncostatin M (OSM), an IL-6 family cytokine, has been implicated in a number of biological processes including the induction of inflammation and the modulation of extracellular matrix. In this study, we demonstrate that OSM is up-regulated in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis and scleroderma, and investigate the pathological consequences of excess OSM in the lungs. Delivery of OSM to the lungs of mice results in a significant recruitment of inflammatory cells, as well as a dose-dependent increase in collagen deposition in the lungs, with pathological correlates to characteristic human interstitial lung disease. To better understand the relationship between OSM-induced inflammation and OSM-induced fibrosis, we used genetically modified mice and show that the fibrotic response is largely independent of B and T lymphocytes, eosinophils, and mast cells. We further explored the mechanisms of OSM-induced inflammation and fibrosis using both protein and genomic array approaches, generating a "fibrotic footprint" for OSM that shows modulation of various matrix metalloproteinases, extracellular matrix components, and cytokines previously implicated in fibrosis. In particular, although the IL-4/IL-13 and TGF-beta pathways have been shown to be important and intertwined of fibrosis, we show that OSM is capable of inducing lung fibrosis independently of these pathways. The demonstration that OSM is a potent mediator of lung inflammation and extracellular matrix accumulation, combined with the up-regulation observed in patients with pulmonary fibrosis, may provide a rationale for therapeutically targeting OSM in human disease.

Magnetic enrichment of bronchial epithelial cells from sputum for lung cancer diagnosis

BACKGROUND

Sputum is an easily accessible diagnostic material for lung cancer early detection by cytologic and molecular genetic analysis of exfoliated airway epithelial cells. However, the use of sputum is limited by its cellular heterogeneity, which includes >95% macrophages and neutrophils and only about 1% bronchial epithelial cells. We propose to obtain concentrated and purified bronchial epithelial cells to improve early detection of lung cancer in sputum samples.

METHODS

Sputum was collected from patients with stage I nonsmall-cell lung cancer, cancer-free smokers, and healthy nonsmokers. Magnetic-assisted cell sorting (MACS) with anti-CD14 and anti-CD16 antibody beads were used to enrich bronchial epithelial cells by depleting macrophages and neutrophils from sputum. Fluorescence in situ hybridization (FISH) analysis for detection of FHIT deletion and cytology were evaluated in the enriched specimens.

RESULTS

The bronchial epithelial cells were concentrated to 40% purity from 1.1% of the starting population, yielding an average of 36-fold enrichment and at least 2.3 x 10(5) cells per sample. Detecting FHIT deletions for lung cancer diagnosis produced 58% sensitivity in the enriched sputum, whereas there was 42% sensitivity in the unenriched samples (P = .02). Cytologic examination of the enriched sputum resulted in 53% sensitivity, as compared with 39% sensitivity in unenriched sputum (P = .03). Furthermore, only 2 cytocentrifuge slides of the unenriched sputum were needed for the analyses, as compared with up to 10 cytocentrifuge slides required from the unprocessed specimens.

CONCLUSIONS

The enrichment of bronchial epithelial cells could improve the diagnostic value of sputum and the efficiency of genetic and cytologic analysis of lung cancer.

Macrophages produce TGF-beta-induced (beta-ig-h3) following ingestion of apoptotic cells and regulate MMP14 levels and collagen turnover in fibroblasts

Phagocytic clearance of apoptotic cells by macrophages is an essential part in the resolution of inflammation. It coincides with activation of repair mechanisms, including accumulation of extracellular matrix. A possible link between clearance of apoptotic debris and accumulation of extracellular matrix has not been investigated. Production of collagen was measured in primary fibroblasts cocultured with macrophages. Ingestion of apoptotic cells by monocyte-derived macrophages led to up-regulation of collagen. Direct contact between macrophages and fibroblasts was not required for collagen up-regulation. Macrophages produced TGF-beta following ingestion of apoptotic cells, but the levels of this cytokine were lower than those required for a significant up-regulation of collagen. Simultaneously, the levels of TGF-beta-induced (TGFBI), or keratoepithelin/BIGH3, mRNA and protein were increased. In contrast, primary alveolar macrophages stimulated collagen production without exposure to apoptotic cells; there was no further increase in the levels of TGFBI, mRNA or protein, or collagen after ingestion of apoptotic cells. Stimulation of fibroblasts with TGFBI down-regulated MMP14 levels, decreased DNA binding by p53, increased DNA binding by PU.1, and up-regulated collagen protein but not mRNA levels. Overexpression of MMP14 or p53, or small interfering RNA-mediated inhibition of PU.1 led to an increase in MMP14 and a decline in collagen levels, whereas small interfering RNA-mediated inhibition of MMP14 led to elevation of collagen levels. In conclusion, monocyte-derived but not alveolar macrophages produce TGFBI following ingestion of apoptotic cells, leading to the down-regulation of MMP14 levels in fibroblasts through a mechanism involving p53 and PU.1, and to subsequent accumulation of collagen.

Detecting genomic aberrations by fluorescence in situ hybridization with quantum dots-labeled probes

Detection of genomic alterations of cancer genes by fluorescent in situ hybridization (FISH) will provide important information for cancer diagnosis and therapy. To effectively and reliably detect the genomic changes, we prepared novel FISH probes by directly conjugating genomic DNA of genes to semiconductor quantum dot fluorophores (QDs). The generated QD-genomic probes are substantially more photostable than the probes labeled with organic dye and show high intensity in both metaphase and interphase cell. The directly labeling probes allow detection of genomic targets in a fast and simple FISH procedure with high sensitivity and specificity. Furthermore, application of the QD-genomic probes in lung cancer specimens can reliably visualize gene amplification in cancer cells. These results suggest that the QD-FISH probes may offer an effective approach to analyze cancer-related genomic aberrations in basic research and clinical applications.