Analysis of bronchoalveolar lavage fluid proteome from systemic sclerosis patients with or without functional, clinical and radiological signs of lung fibrosis

Emerging roles of ferroptosis in pulmonary fibrosis: current perspectives, opportunities and challenges

Pulmonary fibrosis (PF) is a chronic interstitial lung disorder characterized by abnormal myofibroblast activation, accumulation of extracellular matrix (ECM), and thickening of fibrotic alveolar walls, resulting in deteriorated lung function. PF is initiated by dysregulated wound healing processes triggered by factors such as excessive inflammation, oxidative stress, and coronavirus disease (COVID-19). Despite advancements in understanding the disease's pathogenesis, effective preventive and therapeutic interventions are currently lacking. Ferroptosis, an iron-dependent regulated cell death (RCD) mechanism involving lipid peroxidation and glutathione (GSH) depletion, exhibits unique features distinct from other RCD forms (e.g., apoptosis, necrosis, and pyroptosis). Imbalance between reactive oxygen species (ROS) production and detoxification leads to ferroptosis, causing cellular dysfunction through lipid peroxidation, protein modifications, and DNA damage. Emerging evidence points to the crucial role of ferroptosis in PF progression, driving macrophage polarization, fibroblast proliferation, and ECM deposition, ultimately contributing to alveolar cell death and lung tissue scarring. This review provides a comprehensive overview of the latest findings on the involvement and signaling mechanisms of ferroptosis in PF pathogenesis, emphasizing potential novel anti-fibrotic therapeutic approaches targeting ferroptosis for PF management.

Proteomics: Potential techniques for discovering the pathogenesis of connective tissue diseases-interstitial lung disease

Interstitial lung disease (ILD) is one of the most serious lung complications of connective tissue disease (CTD). The application of proteomics in the past decade has revealed that various proteins are involved in the pathogenesis of each subtype of CTD-ILD through different pathways, providing novel ideas to study pathological mechanisms and clinical biomarkers. On this basis, a multidimensional diagnosis or prediction model is established. This paper reviews the results of proteomic detection of different subtypes of CTD-ILD and discusses the role of some differentially expressed proteins in the development of pulmonary fibrosis and their potential clinical applications.

Cystatin SN in type 2 inflammatory airway diseases

Cystatin SN, encoded by CST1, belongs to the type 2 (T2) cystatin protein superfamily. In the past decade, several publications have highlighted the association between cystatin SN and inflammatory airway diseases including chronic rhinosinusitis, rhinitis, asthma, chronic obstructive pulmonary disease, and chronic hypersensitivity pneumonitis. It is, therefore, crucial to understand the role of cystatin SN in the wider context of T2 inflammatory diseases. Here, we review the expression of cystatin SN in airway-related diseases with different endotypes. We also emphasize the physiological and pathological roles of cystatin SN. Physiologically, cystatin SN protects host tissues from destructive proteolysis by cysteine proteases present in the external environment or produced via internal dysregulated expression. Pathologically, the secretion of cystatin SN from airway epithelial cells initiates and amplifies T2 immunity and subsequently leads to disease. We further discuss the development of cystatin SN as a T2 immunity marker that can be monitored noninvasively and assist in airway disease management. The discovery, biology, and inhibition capability are also introduced to better understand the role of cystatin SN in airway diseases.

Enrichr in silico analysis of MS-based extracted candidate proteomic biomarkers highlights pathogenic pathways in systemic sclerosis

Systemic sclerosis (SSc) is a rheumatic disease characterised by vasculopathy, inflammation and fibrosis. Its aetiopathogenesis is still unknown, and the pathways/mechanisms of the disease are not clarified. This study aimed to perform in silico analysis of the already Mass Spectrometry (MS)-based discovered biomarkers of SSc to extract possible pathways/mechanisms implicated in the disease. We recorded all published candidate MS-based found biomarkers related to SSc. We then selected a number of the candidate biomarkers using specific criteria and performed pathway and cellular component analyses using Enrichr. We used PANTHER and STRING to assess the biological processes and the interactions of the recorded proteins, respectively. Pathway analysis extracted several pathways that are associated with the three different stages of SSc pathogenesis. Some of these pathways are also related to other diseases, including autoimmune diseases. We observe that these biomarkers are located in several cellular components and implicated in many biological processes. STRING analysis showed that some proteins interact, creating significant clusters, while others do not display any evidence of an interaction. All these data highlight the complexity of SSc, and further investigation of the extracted pathways/biological processes and interactions may help study the disease from a different angle.

Cathepsin S Contributes to Lung Inflammation in Acute Respiratory Distress Syndrome

Rationale: Although the cysteine protease cathepsin S has been implicated in the pathogenesis of several inflammatory lung diseases, its role has not been examined in the context of acute respiratory distress syndrome, a condition that still lacks specific and effective pharmacological treatments. Objectives: To characterize the status of cathepsin S in acute lung inflammation and examine the role of cathepsin S in disease pathogenesis. Methods: Human and mouse model BAL fluid samples were analyzed for the presence and activity of cathepsin S and its endogenous inhibitors. Recombinant cathepsin S was instilled directly into the lungs of mice. The effects of cathepsin S knockout and pharmacological inhibition were examined in two models of acute lung injury. Protease-activated receptor-1 antagonism was used to test a possible mechanism for cathepsin S-mediated inflammation. Measurements and Main Results: Pulmonary cathepsin S concentrations and activity were elevated in acute respiratory distress syndrome, a phenotype possibly exacerbated by the loss of the endogenous antiprotease cystatin SN. Direct cathepsin S instillation into the lungs induced key pathologies of acute respiratory distress syndrome, including neutrophilia and alveolar leakage. Conversely, in murine models of acute lung injury, genetic knockdown and prophylactic or therapeutic inhibition of cathepsin S reduced neutrophil recruitment and protein leakage. Cathepsin S may partly mediate its pathogenic effects via protease-activated receptor-1, because antagonism of this receptor abrogated cathepsin S-induced airway inflammation. Conclusions: Cathepsin S contributes to acute lung injury and may represent a novel therapeutic target for acute respiratory distress syndrome.

S100A6, Calumenin and Cytohesin 2 as Biomarkers for Cutaneous Involvement in Systemic Sclerosis Patients: A Case Control Study

BACKGROUND

Systemic sclerosis (Ssc) is an autoimmune disease with incomplete known physiopathology. There is a high number of candidate proteomic biomarkers for Ssc that have not yet been confirmed on independent Ssc cohorts. The aim of the study was to confirm circulating S100A6, calumenin, and cytohesin 2 as biomarkers for Ssc.

METHODS

53 Ssc patients and 26 age- and gender-matched controls were included. Serum S100A6, calumenin, and cytohesin 2 were evaluated with commercial ELISA kits. Associations between serum expression and clinical Ssc characteristics were evaluated.

RESULTS

Serum calumenin, S100A6, and cytohesin 2 were higher in Ssc patients compared to controls. Calumenin associated with extensive cutaneous fibrosis, frequency of Raynaud phenomenon, and low complement level, and had a tendency to be higher in Ssc patients with pulmonary fibrosis. S100A6 correlated with the number of active digital ulcers. Serum cytohesin 2 levels were higher in patients with teleangiectasia and associated with pulmonary artery pressure.

CONCLUSIONS

Serum calumenin, S100A6, and cytohesin 2 were confirmed as biomarkers on an independent group of Ssc patients. Calumenin had the best predictive capacity for cutaneous Ssc manifestations. Future studies are needed to evaluate the prognostic value of these biomarkers and evaluate them as possible therapeutic targets.

Calprotectin in Lung Diseases

Calprotectin (CLP) is a heterodimer formed by two S-100 calcium-binding cytosolic proteins, S100A8 and S100A9. It is a multifunctional protein expressed mainly by neutrophils and released extracellularly by activated or damaged cells mediating a broad range of physiological and pathological responses. It has been more than 20 years since the implication of S100A8/A9 in the inflammatory process was shown; however, the evaluation of its role in the pathogenesis of respiratory diseases or its usefulness as a biomarker for the appropriate diagnosis and prognosis of lung diseases have only gained attention in recent years. This review aimed to provide current knowledge regarding the potential role of CLP in the pathophysiology of lung diseases and describe how this knowledge is, up until now, translated into daily clinical practice. CLP is involved in numerous cellular processes in lung health and disease. In addition to its anti-microbial functions, CLP also serves as a molecule with pro- and anti-tumor properties related to cell survival and growth, angiogenesis, DNA damage response, and the remodeling of the extracellular matrix. The findings of this review potentially introduce CLP in daily clinical practice within the spectrum of respiratory diseases.

Calprotectin, an available prognostic biomarker in systemic sclerosis: a systematic review

BACKGROUND

Finding easier and less invasive biologic biomarker in the clinical specimen of systemic sclerosis (SSc) patients can be effective in diagnosing and treating SSc-associated multisystem diseases. The complex of S100A8 and S100A9 (Calprotectin) is an easily available prognostic biomarker that secretes from immune cells and is necessary for initiating the immune response to noninfectious inflammation processes. The present study aims to evaluate the effectiveness of Calprotectin in specimen of SSc patients. We reviewed the evidence for Calprotectin in diagnostic and prognostic of SSc patients.

METHODS

This systematic review was done to identify studies on "Calprotectin" within "SSc" patients. PubMed, Web of knowledge, and Scopus were searched for this purpose. A standardized form was used to extract diseases, sample size, biomarkers identified, source of biomarker, and its effects.

RESULTS

Overall, the 16 articles selected show that the main sources of Calprotectin were plasma, bronchoalveolar lavage fluid, and especially stool.

CONCLUSION

The best source of Calprotectin was fecal Calprotectin that could show the inflammation and small intestinal bacterial overgrowth (SIBO) on SSc patients. Also, the most arguable source is plasma because of its low sample size. Comparing the Calprotectin level in different rheumatic diseases showed the specificity of fecal Calprotectin for SSc disease. Nevertheless, it has to be noted that Calprotectin correlates with some other factors such as age, PIP drug, and nonsteroidal anti-inflammatory drugs.

Quantification of mitochondrial DNA damage and copy number in circulating blood of patients with systemic sclerosis by a qPCR-based assay

Background

Although not fully understood, oxidative stress has been implicated in the pathogenesis of different autoimmune diseases such as systemic sclerosis. Accumulating evidence indicates that oxidative stress can induce mitochondrial DNA (mtDNA) damage and variations in mtDNA copy number (mtDNAcn).

Objective

The aim of this study was to explore mtDNAcn and oxidative DNA damage byproducts in peripheral blood of patients with systemic sclerosis and healthy controls.

Methods

Forty six patients with systemic sclerosis and forty nine healthy subjects were studied. Quantitative real-time PCR used to measure the relative mtDNAcn and the oxidative damage (oxidized purines) of each sample.

Results

The mean mtDNAcn was lower in patients with systemic sclerosis than in healthy controls whereas the degree of mtDNA damage was significantly higher in cases as compared to controls. Moreover, there was a negative correlation between mtDNAcn and oxidative DNA damage.

Study limitations

The lack of simultaneous analysis and quantification of DNA oxidative damage markers in serum or urine of patients with systemic sclerosis and healthy controls.

Conclusion

These data suggest that alteration in mtDNAcn and increased oxidative DNA damage may be involved in the pathogenesis of systemic sclerosis.

HIP/PAP protects against bleomycin-induced lung injury and inflammation and subsequent fibrosis in mice

Hepatocarcinoma‐intestine‐pancreas/pancreatitis‐associated protein (HIP/PAP), a C‐type lectin, exerts anti‐oxidative, anti‐inflammatory, bactericidal, anti‐apoptotic, and mitogenic functions in several cell types and tissues. In this study, we explored the role of HIP/PAP in pulmonary fibrosis (PF). Expression of HIP/PAP and its murine counterpart, Reg3B, was markedly increased in fibrotic human and mouse lung tissues. Adenovirus‐mediated HIP/PAP expression markedly alleviated bleomycin (BLM)‐induced lung injury, inflammation, and fibrosis in mice. Adenovirus‐mediated HIP/PAP expression alleviated oxidative injury and lessened the decrease in pulmonary superoxide dismutase (SOD) activity in BLM‐treated mice, increased pulmonary SOD expression in normal mice, and HIP/PAP upregulated SOD expression in cultured human alveolar epithelial cells (A549) and human lung fibroblasts (HLF‐1). Moreover, in vitro experiments showed that HIP/PAP suppressed the growth of HLF‐1 and ameliorated the H₂O₂‐induced apoptosis of human alveolar epithelial cells (A549 and HPAEpiC) and human pulmonary microvascular endothelial cells (HPMVEC). In HLF‐1, A549, HPAEpiC, and HPMVEC cells, HIP/PAP did not affect the basal levels, but alleviated the TGF‐β1‐induced down‐regulation of the epithelial/endothelial markers E‐cadherin and vE‐cadherin and the over‐expression of mesenchymal markers, such as α‐SMA and vimentin. In conclusion, HIP/PAP was found to serve as a potent protective factor in lung injury, inflammation, and fibrosis by attenuating oxidative injury, promoting the regeneration of alveolar epithelial cells, and antagonizing the pro‐fibrotic actions of the TGF‐β1/Smad signaling pathway.

Neutrophil-derived exosome from systemic sclerosis inhibits the proliferation and migration of endothelial cells

OBJECTIVES

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, inflammation, and extensive fibrosis in multiple organs. Exosomes (EXOs) are cell-derived vesicles contained various DNAs, RNAs and proteins, and play important roles in various diseases. Here, we aimed to investigate the roles of SSc EXOs in angiogenesis related mechanisms.

METHODS

EXOs were isolated from plasma, cultured peripheral blood mononuclear cells (PBMCs)/neutrophil supernatants, and identified by transmission electron microscopy. The expression of S100A8/A9 was measured by real-time PCR and ELISA. Proliferation, migration and scratch assays in human dermal microvascular endothelial cells (HDMECs) were used to study the EXOs influence.

RESULTS

Plasma and neutrophil EXOs from SSc patients can suppress the proliferation and migration of HDMECs. High levels of S100A8/A9 were found in SSc EXOs which derived from plasma, PBMCs and neutrophils. The expression of S100A8/A9 in neutrophil EXOs was higher than that in PBMC EXOs in SSc patients. The proliferation and migration of HDMECs were possibly inhibited by S100A8/A9 of neutrophil EXOs.

CONCLUSIONS

Neutrophil EXOs from SSc patients inhibits the proliferation and migration of HDMECs, S100A8/A9 might play an important role in this process.

Glutathione Transferase P1-1 an Enzyme Useful in Biomedicine and as Biomarker in Clinical Practice and in Environmental Pollution

Glutathione transferase P1-1 (GSTP1-1) is expressed in some human tissues and is abundant in mammalian erythrocytes (here termed e-GST). This enzyme is able to detoxify the cell from endogenous and exogenous toxic compounds by using glutathione (GSH) or by acting as a ligandin. This review collects studies that propose GSTP1-1 as a useful biomarker in different fields of application. The most relevant studies are focused on GSTP1-1 as a biosensor to detect blood toxicity in patients affected by kidney diseases. In fact, this detoxifying enzyme is over-expressed in erythrocytes when unusual amounts of toxins are present in the body. Here we review articles concerning the level of GST in chronic kidney disease patients, in maintenance hemodialysis patients and to assess dialysis adequacy. GST is also over-expressed in autoimmune disease like scleroderma, and in kidney transplant patients and it may be used to check the efficiency of transplanted kidneys. The involvement of GSTP in the oxidative stress and in other human pathologies like cancer, liver and neurodegenerative diseases, and psychiatric disorders is also reported. Promising applications of e-GST discussed in the present review are its use for monitoring human subjects living in polluted areas and mammals for veterinary purpose.

A Pilot Study to Investigate the Balance between Proteases and α1-Antitrypsin in Bronchoalveolar Lavage Fluid of Lung Transplant Recipients

The neutrophilic component in bronchiolitis obliterans syndrome (BOS, the main form of chronic lung rejection), plays a crucial role in the pathogenesis and maintenance of the disorder. Human Neutrophil Elastase (HNE), a serine protease responsible of elastin degradation whose action is counteracted by α1-antitrypsin (AAT), a serum inhibitor specific for this protease. This work aimed to investigate the relationship between HNE and AAT in bronchoalveolar lavage fluid (BALf) from stable lung transplant recipients and BOS patients to understand whether the imbalance between proteases and inhibitors is relevant to the development of BOS. To reach this goal a multidisciplinary procedure was applied which included: (i) the use of electrophoresis/western blotting coupled with liquid chromatography-mass spectrometric analysis; (ii) the functional evaluation of the residual antiprotease activity, and (iii) a neutrophil count. The results of these experiments demonstrated, for the first time, the presence of the complex between HNE and AAT in a number of BALf samples. The lack of this complex in a few specimens analyzed was investigated in relation to a patient’s lung inflammation. The neutrophil count and the determination of HNE and AAT activities allowed us to speculate that the presence of the complex correlated with the level of lung inflammation.

Measuring Calumenin Impact on ER-Calcium Depletion Using Transient Calumenin Overexpression and Silencing

Calumenin is a secretory pathway protein regulating different endoplasmic reticulum (ER) proteins such as the sarco-endoplasmic reticulum calcium ATPase (SERCA) pumps. Combined with its diverse cellular distribution, its calcium-binding ability, and its interaction with proteins involved in calcium signaling, it is easy to speculate on future description of important roles of calumenin in calcium homeostasis in many cell types, as it was initially observed in muscle cells. In this chapter, we describe basic techniques to modulate calumenin expression and detect its impact on ER calcium content using classic transfection and Western blot techniques, as well as ER calcium measurement using microplate reader.

Identification of pathogenic genes and upstream regulators in allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is the main cause of irreversible blindness in older individuals. Our study aims to identify the key genes and upstream regulators in AR.

METHODS

To screen pathogenic genes of AR, an integrated analysis was performed by using the microarray datasets in AR derived from the Gene Expression Omnibus (GEO) database. The functional annotation and potential pathways of differentially expressed genes (DEGs) were further discovered by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. We constructed the AR-specific transcriptional regulatory network to find the crucial transcriptional factors (TFs) which target the DEGs in AR. Electronic validation was performed to verify the DEGs obtained by integrated analysis.

RESULTS

From two GEO datasets obtained, we identified 793 DEGs (460 up-regulated and 333 down-regulated genes) between AR and normal control (NC). After GO and KEGG analysis, chronic inflammatory response and MAPK signaling pathway were significantly enriched pathways for DEGs. The expression of 6 genes (CLC, CST1, CRTAM, ILK, STAT1, and POSTN) was detected. The 6 genes in GEO: GSE51392 dataset played the same pattern with that in our integrated analysis.

CONCLUSIONS

The dysregulation of 3 genes (CST1, CLC and STAT1) may be involved in the pathogenesis of AR. AP-1 was associated with AR by regulating CST1 and CLC. Our finding can contribute to developing new potential biomarkers, revealing the underlying pathogenesis, and further raising new therapeutic targets for AR.

Identification of apolipoprotein A-I in BALF as a biomarker of sarcoidosis

Background: Sarcoidosis goes into remission in two-thirds of patients with sarcoidosis, but about 20 % of patients develop pulmonary fibrosis. The mechanisms of pulmonary fibrosis in sarcoidosis and differences in pathogenesis between clinical stages are still unclear. Objectives: The aim of this study was investigating proteins associated with clinical stages by comparing bronchoalveolar lavage fluid (BALF) protein between stage I and stage IV using proteome analysis. Methods: Proteomic differences in BALF were compared between stage I and stage IV by examining BALF from 8 stage I patients and 5 stage IV patients by two-dimensional gel electrophoresis and mass spectrometry. Results: In individual comparisons of BALF samples, the levels of apolipoprotein (Apo) A-I fragment, fibrinogen γ chain, calcyphosine, complement C3, and surfactant protein A were significantly higher in stage I than in stage IV. In contrast, none of the proteins examined significantly higher in stage IV than in stage I. To confirm the results of Apo A-I in the BALF proteome, we performed enzyme-linked immunosorbent assay (ELISA) in a larger group. The concentration of BALF Apo A-I was significantly higher in stage I patients than in stage IV patients (0.70 [0.13-0.89] vs. 0.15 [0.08-0.21] ng/μg protein, p=0.003). Conclusion: The involvement of BALF Apo A-I in sarcoidosis may differ between stage I and stage IV. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 5-15).

S100A9 aggravates bleomycin-induced dermal fibrosis in mice via activation of ERK1/2 MAPK and NF-κB pathways

OBJECTIVES

This study aims to investigate the pathogenicity and possible mechanisms of S100A9 function in mice models of scleroderma.

MATERIALS AND METHODS

The content of S100A9 in the skin tissues of mice with scleroderma was determined. Different concentrations of bleomycin (BLM) and S100A9 were subcutaneously injected into the backs of mice simultaneously, and then pathological changes in the skin of these mice were monitored. Specifically, the levels of inflammatory cytokines and alpha smooth muscle actin (α-SMA), the activation of extracellular regulated kinase 1/2 (ERK1/2), mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways, and the expression of the receptor for advanced glycation end-product (RAGE) in the skin were determined.

RESULTS

The content of S100A9 in the skin tissues of mice with scleroderma was determined. Different concentrations of BLM and S100A9 were subcutaneously injected into the backs of mice simultaneously, and then pathological changes in the skin of these mice were monitored. Specifically, the levels of inflammatory cytokines and alpha smooth muscle actin (α-SMA), the activation of extracellular regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways, and the expression of the receptor for advanced glycation end-product (RAGE) in the skin were determined.

CONCLUSION

S100A9 aggravates dermal fibrosis in BLM-induced scleroderma (BIS) mice, and its mechanisms might be mediated by RAGE, ERK1/2, and NF-κB pathway.

Clinical and molecular features of rapidly progressive chronic hypersensitivity pneumonitis

Background: Chronic hypersensitivity pneumonitis (CHP) is characterized by varying degrees of inflammation and fibrosis of the lungs caused by a variety of inhaled antigens. Despite extensive efforts to minimize exposure to the antigens, patients with CHP sometimes experience rapid deterioration of their pulmonary functions, resulting in death within a few years. Objectives: This study aimed to define clearly the clinical and molecular features of patients with rapidly progressive CHP. Methods: Annual decline in pulmonary functions and its association with clinical variables was evaluated in 43 patients with CHP. The RNA from frozen lung specimens of nine patients with rapidly progressive CHP and normal control subjects was profiled using Illumina HumanWG-6 v3 Expression BeadChips, and an Ingenuity Pathway Analysis was performed to identify the altered functional and canonical signaling pathways. Results: Patients with more than 10% annual decline in forced vital capacity and those with more than 15% annual decline in diffusion capacity for carbon monoxide showed significantly poor overall survival rates (p=0.002 and p=0.001, respectively). According to the gene expression analysis, 160 genes, including cystatin SN (CST1), ephrin-A2 (EFNA2), and wingless-type MMTV integration site family, member 7B (WNT7B) were upregulated, and pathways related to inflammatory responses and autoimmune diseases were differentially expressed. Conclusion: Greater annual decline in pulmonary function can predict poorer prognosis of patients with CHP. Genes and pathways related to inflammatory responses and autoimmune diseases have potential roles in the pathogenesis of rapidly progressive CHP, suggesting their potential as diagnostic biomarkers and/or therapeutic targets. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 48-57).

Fragmented gelsolins are increased in rheumatoid arthritis-associated interstitial lung disease with usual interstitial pneumonia pattern

BACKGROUND

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) occurs in 10%-30% of patients with RA, and interstitial lung disease (ILD) is associated with increased mortality in up to 10% of patients with RA. The pathogenesis of RA-ILD is virtually unknown. The aim of this study is to investigate the proteins related to UIP pattern by comparing to OP pattern in RA-ILD using proteome analysis of bronchoalveolar lavage fluid (BALF).

METHODS

Proteomic differences in BALF were compared between the UIP pattern and OP pattern by examining BALF from 5 patients with the UIP pattern and 7 patients with the OP pattern by two-dimensional gel electrophoresis and mass spectrometry.

RESULTS

In individual comparisons of BALF samples, the levels of the protein gelsolin and Ig kappa chain C region were significantly higher in the UIP pattern than in the OP pattern. In contrast, the levels of α-1 antitrypsin, CRP, haptoglobin β, and surfactant protein A (isoform number 5) were all significantly higher in the OP pattern than in the UIP pattern. Gelsolin was cleaved into two fragments, a C-terminal half and N-terminal half, and the levels of both were significantly higher in the UIP pattern than in the OP pattern.

CONCLUSIONS

Fragmented gelsolins may be associated with the pathogenesis of fibrosis in RA-ILD.

Calprotectin in rheumatic diseases

Calprotectin is a heterodimer formed by two proteins, S100A8 and S100A9, which are mainly produced by activated monocytes and neutrophils in the circulation and in inflamed tissues. The implication of calprotectin in the inflammatory process has already been demonstrated, but its role in the pathogenesis, diagnosis, and monitoring of rheumatic diseases has gained great attention in recent years. Calprotectin, being stable at room temperature, is a candidate biomarker for the follow-up of disease activity in many autoimmune disorders, where it can predict response to treatment or disease relapse. There is evidence that a number of immunomodulators, including TNF-α inhibitors, may reduce calprotectin expression. S100A8 and S100A9 have a potential role as a target of treatment in murine models of autoimmune disorders, since the direct or indirect blockade of these proteins results in amelioration of the disease process. In this review, we will go over the biologic functions of calprotectin which might be involved in the etiology of rheumatic disorders. We will also report evidence of its potential use as a disease biomarker. Impact statement Calprotectin is an acute-phase protein produced by monocytes and neutrophils in the circulation and inflamed tissues. Calprotectin seems to be more sensitive than CRP, being able to detect minimal residual inflammation and is a candidate biomarker in inflammatory diseases. High serum levels are associated with some severe manifestations of rheumatic diseases, such as glomerulonephritis and lung fibrosis. Calprotectin levels in other fluids, such as saliva and synovial fluid, might be helpful in the diagnosis of rheumatic diseases. Of interest is also the potential role of calprotectin as a target of treatment.

Systemic sclerosis biomarkers discovered using mass-spectrometry-based proteomics: a systematic review

CONTEXT

Systemic sclerosis (SSc) is an autoimmune disease with incompletely known physiopathology. There is a great challenge to predict its course and therapeutic response using biomarkers.

OBJECTIVE

To critically review proteomic biomarkers discovered from biological specimens from systemic sclerosis patients using mass spectrometry technologies.

METHODS

Medline and Embase databases were searched in February 2014.

RESULTS

Out of the 199 records retrieved, a total of 20 records were included, identifying 116 candidate proteomic biomarkers.

CONCLUSION

Research in SSc proteomic biomarkers should focus on biomarker validation, as there are valuable mass-spectrometry proteomics studies in the literature.

Airway symptoms and biological markers in nasal lavage fluid in subjects exposed to metalworking fluids

BACKGROUNDS

Occurrence of airway irritation among industrial metal workers was investigated. The aims were to study the association between exposures from water-based metal working fluids (MWF) and the health outcome among the personnel, to assess potential effects on the proteome in nasal mucous membranes, and evaluate preventive actions.

METHODS

The prevalence of airway symptoms related to work were examined among 271 metalworkers exposed to MWF and 24 metal workers not exposed to MWF at the same factory. At the same time, air levels of potentially harmful substances (oil mist, morpholine, monoethanolamine, formaldehyde) generated from MWF was measured. Nasal lavage fluid was collected from 13 workers and 15 controls and protein profiles were determined by a proteomic approach.

RESULTS

Airway symptoms were reported in 39% of the workers exposed to MWF although the measured levels of MWF substances in the work place air were low. Highest prevalence was found among workers handling the MWF machines but also those working in the same hall were affected. Improvement of the ventilation to reduce MWF exposure lowered the prevalence of airway problems. Protein profiling showed significantly higher levels of S100-A9 and lower levels of SPLUNC1, cystatin SN, Ig J and β2-microglobulin among workers with airway symptoms.

CONCLUSIONS

This study confirms that upper airway symptoms among metal workers are a common problem and despite low levels of MWF-generated substances, effects on airway immune proteins are found. Further studies to clarify the role of specific MWF components in connection to airway inflammation and the identified biological markers are warranted.

S100A9 promotes human lung fibroblast cells activation through receptor for advanced glycation end-product-mediated extracellular-regulated kinase 1/2, mitogen-activated protein-kinase and nuclear factor-κB-dependent pathways

S100A9 belongs to the S100 family of calcium-binding proteins and plays a key role in many inflammatory conditions. Recent studies have found that S100A9 was elevated significantly in the bronchoalveolar lavage fluid of idiopathic pulmonary fibrosis patients, and might be a biomarker for fibrotic interstitial lung diseases. However, the exact function of S100A9 in pulmonary fibrosis needs further studies. We performed this study to investigate the effect of S100A9 on human embryo lung fibroblast (HLF) proliferation and production of cytokines and collagen, providing new insights into the possible mechanism. S100A9 promoted proliferation of fibroblasts and up-regulated expression of both proinflammatory cytokines interleukin (IL)-6, IL-8, IL-1β and collagen type III. S100A9 also induced HLF cells to produce α-smooth muscle actin (α-SMA) and receptor for advanced glycation end-product (RAGE). In addition, S100A9 caused a significant increase in extracellular-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) phosphorylation, while the status of p38 and c-Jun N-terminal kinase (JNK) phosphorylation remained unchanged. Treatment of cells with S100A9 also enhanced nuclear factor kappa B (NF-κB) activation. RAGE blocking antibody pretreatment inhibited the S100A9-induced cell proliferation, cytokine production and pathway phosphorylation. S100A9-mediated cell activation was suppressed significantly by ERK1/2 MAPK inhibitor and NF-κB inhibitor. In conclusion, S100A9 promoted HLF cell growth and induced cells to secret proinflammatory cytokines and collagen through RAGE signalling and activation of ERK1/2 MAPK and NF-κB pathways.

Increased expression of S100A8 and S100A9 in patients with diffuse cutaneous systemic sclerosis. A correlation with organ involvement and immunological abnormalities

S100A8 and S100A9 play important roles in immune and inflammatory disorders. The role of the two proteins in systemic sclerosis (SSc) remains unknown. Fifty-seven diffuse cutaneous SSc (dcSSc) patients, 31 limited cutaneous SSc (lcSSc) patients were recruited in the present study. The expression of S100A8 and S100A9 in plasma was measured using an enzyme-linked immunosorbent assay and the mRNA levels in peripheral blood were assessed using reverse transcriptase quantitative PCR. The expression and distribution of S100A8, S100A9, and receptor for advanced glycation end products (RAGE), in skin tissues was analyzed by immunohistochemistry. The plasma concentrations of S100A8 and S100A9 were significantly higher in dcSSc patients than in normal controls and lcSSc patients. Both S100A8 and S100A9 levels were significantly increased in dcSSc patients with lung or kidney involvement. Increased plasma levels of S100A8 and S100A9 in dcSSc patients were associated with several autoantibodies. Transcription levels of S100A8 and S100A9 in peripheral blood were found elevated in both dcSSc and lcSSc patients than normal controls. Immunohistochemistry demonstrated higher S100A8 and S100A9 expression in sclerotic skin than in normal skin. The number of S100A8, S100A9, or RAGE positive fibroblasts was also significantly increased. Highly elevated expression of both S100A8 and S100A9 was found in dcSSc patients. There was close correlation with disease severity and serological abnormalities, suggesting that the two proteins may play important roles in the development of systemic sclerosis.

Pharmacology and rationale for imatinib in the treatment of scleroderma

Systemic sclerosis (scleroderma) is a chronic, multisystem, fibrotic disease. Although the pathogenesis is not completely understood, early vascular damage leads to an inflammatory reaction and a severe fibrotic response. Therapy of systemic sclerosis is still not convincing and is mainly restricted to the management of organ complications. A wide choice of immunosuppressive and antifibrotic drugs has been used to try to modify the course of the disease, but significant breakthroughs are still lacking. Imatinib is a tyrosine kinase inhibitor known to regulate growth, proliferation, and differentiation as well as apoptosis of cells and is already widely used for several malignancies, eg, chronic myeloid leukemia and gastrointestinal stromal tumors. It has been used in preclinical as well as clinical studies to modulate the fibrotic process in patients with systemic sclerosis. This is based on its activity to interfere selectively with both the transforming growth factor-β and platelet-derived growth factor signaling pathway. Preclinical studies in mouse models of scleroderma showed significant anti-inflammatory and antifibrotic effects; however, several clinical, proof-of-concept trials have not yet confirmed these initially promising results.

Nested case control study of proteomic biomarkers for interstitial lung disease in Japanese patients with non-small-cell lung cancer treated with erlotinib: a multicenter phase IV study (JO21661)

BACKGROUND

Interstitial lung disease (ILD) is a serious adverse drug reaction associated with epidermal growth factor receptor tyrosine-kinase inhibitors (EGFR TKIs). Its risk factors are yet to be fully elucidated. We sought to identify proteomic biomarkers associated with ILD development in erlotinib-treated Japanese patients with non-small-cell lung cancer (NSCLC) to build predictive models.

PATIENTS AND METHODS

We conducted a nested case-control study. The participants were patients with NSCLC enrolled in a phase IV study of erlotinib in whom ILD developed within 120 days after erlotinib administration. The controls were randomly selected patients without ILD from the overall study cohort who were also treated with erlotinib. Serum samples were obtained before the first administration of erlotinib and were assayed by liquid chromatography-mass spectroscopy/mass spectroscopy (LC-MS/MS). Logistic regression analysis was performed to identify the peptide and proteins associated with ILD.

RESULTS

A total of 645 patients were enrolled in the cohort; 15 case patients and 64 controls were analyzed. When multiplicity was taken into account, we were unable to statistically verify any genuine association between individual markers and ILD. Investigation of the predictive power based on leave-one-out cross-validation (LOOCV) showed that the area under the receiver operating characteristic curve was 0.73 at a maximum. Additional analysis suggested that 3 proteins (C3, C4A/C4B, and APOA1) have a stronger association with ILD than do the other proteins tested.

CONCLUSION

We were unable to demonstrate predictive serum protein markers for ILD development. However, C3, C4A/C4B, and APOA1 are worthy of further investigation.

Altered DNA methylation profile in idiopathic pulmonary fibrosis

RATIONALE

DNA methylation is an important epigenetic mechanism, which often occurs in response to environmental stimuli and is crucial in regulating gene expression. It is likely that epigenetic alterations contribute to pathogenesis in idiopathic pulmonary fibrosis (IPF).

OBJECTIVES

To determine the DNA methylation changes in IPF and their effects on gene expression.

METHODS

Total DNA methylation and DNA methyltransferase expression were compared in IPF and normal control lung tissues. IPF and normal tissues were subjected to comparative analysis of genome-wide DNA methylation and RNA expression using DNA hybridization to the Illumina HumanMethylation27 BeadChip and RNA hybridization to Illumina HumanHT-12 BeadChip. Functional analyses of differentially expressed and differentially methylated genes were done. Selected genes were validated at DNA, RNA, and protein levels.

MEASUREMENTS AND MAIN RESULTS

DNA methylation status was altered in IPF. IPF samples demonstrated higher DNA methyltransferase expression without observed alterations in global DNA methylation. Genome-wide differences in DNA methylation status and RNA expression were demonstrated by array hybridization. Among the genes whose DNA methylation status and RNA expression were both significantly altered, 16 genes were hypermethylated in DNA associated with decreased mRNA expression or vice versa. We validated CLDN5, ZNF467, TP53INP1, and DDAH1 genes at the level of DNA methylation status, RNA, and protein-level expression.

CONCLUSIONS

Changes in DNA methylation correspond to altered mRNA expression of a number of genes, some with known and others with previously uncharacterized roles in IPF, suggesting that DNA methylation is important in the pathogenesis of IPF.

Proteome analysis of bronchoalveolar lavage fluid in chronic hypersensitivity pneumonitis

BACKGROUND

Hypersensitivity pneumonitis (HP) is an immune-mediated lung disease induced by inhalation of numerous antigens. Pathologically, chronic HP tends to show usual interstitial pneumonia (UIP) and fibrotic nonspecific interstitial pneumonia (fNSIP) patterns. Patients with UIP pattern present insidious onset and a risk for acute exacerbations.

METHODS

To evaluate the proteomic differences of bronchoalveolar lavage fluid (BALF) between UIP and fNSIP patterns, BALF from seven patients with UIP pattern and four patients with fNSIP pattern was examined using two-dimensional gel electrophoresis and mass spectrometry.

RESULTS

By individually comparing each BALF sample, we found that the protein levels of surfactant protein A (SP-A), immunoglobulin heavy chain α, α-2 heat shock glycoprotein, haptoglobin β, and immunoglobulin J chain were significantly higher in the patients with UIP pattern than those in the patients with fNSIP pattern. In contrast, the protein levels of glutathione s-transferase, vitamin D-binding protein, and β-actin were significantly higher in the patients with fNSIP pattern than those in the patients with UIP pattern. To confirm the results of SP-A in the BALF proteome, we performed enzyme-linked immunosorbent assay in a larger group. The concentrations of SP-A in BALF from the patients with UIP pattern were significantly higher than those from the patients with fNSIP pattern (2.331 ± 1.656 μg/ml vs. 1.319 ± 1.916 μg/ml, p = 0.034).

CONCLUSIONS

We identified several proteins that may play roles in the development of pathological differences between UIP and fNSIP patterns of chronic HP.

Contributions of mass spectrometry-based proteomics to defining cellular mechanisms and diagnostic markers for systemic lupus erythematosus

Systematic lupus erythematosus (SLE) is a complex disease for which molecular diagnostics are limited and pathogenesis is not clearly understood. Important information is provided in this regard by identification and characterization of more specific molecular and cellular targets in SLE immune cells and target tissue and markers of early-onset and effective response to treatment of SLE complications. In recent years, advances in proteomic technologies and applications have facilitated such discoveries. Here we provide a review of insights into SLE pathogenesis, diagnosis and treatment that have been provided by mass spectrometry-based proteomic approaches.

Efficacy of low-dose imatinib mesylate for cutaneous involvement in systemic sclerosis: a preliminary report of three cases

In this pilot study, the effect of low-dose imatinib mesylate (100 mg/day) on cutaneous involvement in patients with systemic sclerosis (SSc) was analyzed. Three patients with SSc were treated with 100 mg/day of imatinib mesylate for 6 months because of pulmonary arterial hypertension refractory to conventional treatments, including beraprost, bosentan, sildenafil, and epoprostenol. Changes in cutaneous involvement were evaluated at 1, 3, and 6 months. During the treatment, the total skin score gradually improved in all of the patients. Contracture of phalanges was attenuated in two patients, one of whom also experienced the partial restoration of large-joint mobility. Nailfold bleeding, initially seen in two patients, was gradually attenuated and had completely disappeared at 6 months. In all patients, Raynaud's phenomenon was attenuated at around 3 months and had completely disappeared at 6 months. Although transient renal dysfunction was observed in one patient, none of the patients experienced common adverse effects of imatinib, such as edema, nausea, rash, and musculoskeletal pain. These clinical data indicate the tolerability and efficacy of low-dose imatinib in SSc, especially against cutaneous vascular involvement, including Raynaud's phenomenon and nailfold bleeding.

Pooled genome-wide analysis to identify novel risk loci for pediatric allergic asthma

Background

Genome-wide association studies of pooled DNA samples were shown to be a valuable tool to identify candidate SNPs associated to a phenotype. No such study was up to now applied to childhood allergic asthma, even if the very high complexity of asthma genetics is an appropriate field to explore the potential of pooled GWAS approach.

Methodology/Principal Findings

We performed a pooled GWAS and individual genotyping in 269 children with allergic respiratory diseases comparing allergic children with and without asthma. We used a modular approach to identify the most significant loci associated with asthma by combining silhouette statistics and physical distance method with cluster-adapted thresholding. We found 97% concordance between pooled GWAS and individual genotyping, with 36 out of 37 top-scoring SNPs significant at individual genotyping level. The most significant SNP is located inside the coding sequence of C5, an already identified asthma susceptibility gene, while the other loci regulate functions that are relevant to bronchial physiopathology, as immune- or inflammation-mediated mechanisms and airway smooth muscle contraction. Integration with gene expression data showed that almost half of the putative susceptibility genes are differentially expressed in experimental asthma mouse models.

Conclusion/Significance

Combined silhouette statistics and cluster-adapted physical distance threshold analysis of pooled GWAS data is an efficient method to identify candidate SNP associated to asthma development in an allergic pediatric population.

Proteome analysis of biological fluids from autoimmune-rheumatological disorders

Autoimmune-rheumatological diseases are worldwide distributed disorders and represent a complex array of illnesses characterized by autoreactivity (reactivity against self-antigens) of T-B lymphocytes and by the synthesis of autoantibodies crucial for diagnosis (biomarkers). Yet, the effects of the autoimmune chronic inflammation on the infiltrated tissues and organs generally lead to profound tissue and organ damage with loss of function (i.e., lung, kidney, joints, exocrine glands). Although progresses have been made on the knowledge of these disorders, much still remains to be investigated on their pathogenesis and identification of new biomarkers useful in clinical practice. The rationale of using proteomics in autoimmune-rheumatological diseases has been the unmet need to collect, from biological fluids that are easily obtainable, a summary of the final biochemical events that represent the effects of the interplay between immune cells, mesenchymal cells and endothelial cells. Proteomic analysis of these fluids shows encouraging results and in this review, we addressed four major autoimmune-rheumatological diseases investigated through proteomic techniques and provide evidence-based data on the highlights obtained in systemic sclerosis, primary and secondary Sjogren's syndrome, systemic lupus erythematosus and rheumatoid arthritis.

Proteome analysis of bronchoalveolar lavage fluid in lung fibrosis associated with systemic sclerosis

BACKGROUND

Interstitial lung disease (ILD) is the major cause of mortality in collagen vascular diseases. However, its pathogenesis still needs to be elucidated.

METHODS

To evaluate the alteration of certain proteins in bronchoalveolar lavage fluid (BALF) and clarify the causative role in the processes of ILD in systemic sclerosis (SSc), we compared a BALF protein profile between 5 patients with systemic sclerosis with pulmonary fibrosis (SSc-fib+) and 4 patients with systemic sclerosis without pulmonary fibrosis (SSc-fib-) using two-dimensional gel electrophoresis (2-DE), and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS).

RESULTS

We analyzed spots over the range of 10.1kDa to 207.4kDa. SSc-fib+ patients showed increased 3 proteins compared to SSc-fib- including α2-macroglobulin, α1-antitrypsin, and pulmonary surfactant protein A and decreased 2 proteins including α2 heat shock protein (HSP) and glutathione S-transferase (GST) compared to SSc-fib- patients.

CONCLUSIONS

In conclusion, we identified several interesting proteins that might have roles in ILD of SSc patients. Further studies are warranted to clarify the role of these proteins in the processes of pulmonary fibrosis in SSc.

Proteomics of lung cell biology and pulmonary disease

Proteomics has the goal of defining the complete protein complement of biological systems, which can then be analyzed in a comparative fashion to generate informative data regarding protein expression and function. Proteomic analyses can also facilitate the discovery of biomarkers that can be used to diagnose and monitor disease severity, activity and therapeutic response, as well as to identify new targets for drug development. A major challenge for proteomics, however, has been detecting low-abundance proteins in complex biological fluids. This review summarizes how proteomic analyses have advanced lung cell biology and facilitated the identification of new mechanisms of disease pathogenesis in respiratory disorders, such as asthma, cystic fibrosis, lung cancer, acute lung injury and sarcoidosis. The impact of nanotechnology and microfluidics, as well as studies of post-translational modifications and protein-protein interactions (the interactome), are considered. Furthermore, the application of systems-biology approaches to organize and analyze data regarding the lung proteome, interactome, genome, transcriptome, metabolome, glycome and small RNAome (regulatory RNAs), should facilitate future conceptual advances regarding lung cell biology, disease pathogenesis, biomarker discovery and drug development.

Bronchoalveolar lavage fluid peptidomics suggests a possible matrix metalloproteinase-3 role in bronchopulmonary dysplasia

BACKGROUND

Bronchoalveolar lavage fluid (BALF) is an important diagnostic source to investigate molecular changes occurring in lung disorders. The objective of this study was to assess and compare the peptidomic profiles of BALF from premature neonates with and without bronchopulmonary dysplasia (BPD).

METHODS

Samples were obtained on the 3rd day of life from 34 neonates with gestational age <or=32 weeks. Two pools of samples from patients with and without BPD were analyzed by high performance liquid chromatography. Several differentially expressed peptides were collected and sequenced. Moreover, samples from single donors were analyzed by liquid chromatography-electrospray ionization mass spectrometry to define the molecular mass values of various peptides and to quantify their expression. Levels of some matrix metalloproteinases and their tissue inhibitors were also determined in single samples.

RESULTS

Neonates of the BPD group (N = 16) showed significantly lower mean gestational age and birth weight with respect to the no-BPD group (N = 18; P < 0.0001). Levels of six peptides were significantly higher in BPD patients (P < 0.05). Two of them were identified as the albumin fragments 1-21 (2,428 Da) and 399-406 (956 Da). Levels of matrix metalloproteinase-3 (MMP-3) enzyme probably involved in albumin fragment generation were also significantly higher in the BPD group compared to the no-BPD group (P < 0.05), whereas the levels of tissue inhibitor of metalloproteinases-1 were significantly lower (P < 0.05). Levels of albumin fragments and MMP-3 showed a significant correlation (P < 0.05).

CONCLUSIONS

This study shows that proteomic techniques can be applied to investigate the involvement of proteolytic enzymes on the airways of mechanically ventilated premature infants.

The rapidly expanding CREC protein family: members, localization, function, and role in disease

Although many aspects of the physiological and pathophysiological mechanisms remain unknown, recent advances in our knowledge suggest that the CREC proteins are promising disease biomarkers or targets for therapeutic intervention in a variety of diseases. The CREC family of low affinity, Ca2+-binding, multiple EF-hand proteins are encoded by five genes, RCN1, RCN2, RCN3, SDF4, and CALU, resulting in reticulocalbin, ER Ca2+-binding protein of 55 kDa (ERC-55), reticulocalbin-3, Ca2+-binding protein of 45 kDa (Cab45), and calumenin. Alternative splicing increases the number of gene products. The proteins are localized in the cytosol, in various parts of the secretory pathway, secreted to the extracellular space or localized on the cell surface. The emerging functions appear to be highly diverse. The proteins interact with several different ligands. Rather well-described functions are attached to calumenin with the inhibition of several proteins in the endoplasmic or sarcoplasmic reticulum membrane, the vitamin K(1) 2,3-epoxide reductase, the gamma-carboxylase, the ryanodine receptor, and the Ca2+-transporting ATPase. Other functions concern participation in the secretory process, chaperone activity, signal transduction as well as participation in a large variety of disease processes.

Bronchoalveoloar lavage fluid cytokines and chemokines as markers and predictors for the outcome of interstitial lung disease in systemic sclerosis patients

Introduction

Interstitial lung disease (ILD) is a frequent manifestation of systemic sclerosis (SSc), and cytokines can contribute to the disease pathology. The aim of the current study was to identify specific changes in cytokine levels that may serve as disease markers and possible targets for therapy.

Methods

Cytokines were measured with bioplex analysis in 38 bronchoalveolar fluids (BALFs) from 32 SSc patients (27 with alveolitis and 11 without alveolitis) and 26 control patients. In the case of SSc patients, cytokines were correlated with the respective bronchoalveolar lavage (BAL) cell differentiation, lung function, and thoracic HR-CT score. For 35 BALF samples derived from 29 SSc patients, follow-up investigations of clinical data, lung-function parameter, or thoracic HR-CT scans were available to evaluate the predictive capacity of BALF cytokines and chemokines.

Results

High IL-7 levels were characteristic of SSc-associated interstitial lung disease (ILD) and, in addition, when compared with ILD-negative SSc patients, ILD-positive SSc patients revealed higher IL-4, IL-6, IL-8, and CCL2 (MCP-1) BALF levels. High CCL2 and IL-8 BALF concentrations were associated with neutrophilic and mixed alveolitis. Cytokine levels of IL-4, IL-8, and CCL2 correlated negatively with lung-function parameters; CCL2 concentrations also correlated with HR-CT scores. High concentrations of several cytokines were associated with the progress of ILD and end-stage ILD. Univariate analyses revealed high IL-2 and tumor necrosis factor-alpha (TNF-α) levels as the best predictors for progressive disease, together with lung-function parameters, young age, and neutrophilic alveolitis. Multivariate analyses partially confirmed these results but did not sufficiently converge because of the limited number of patients.

Conclusions

The association of BALF cytokines with lung fibrosis and its progress suggests that cytokines contribute to the pathogenesis of ILD and hence could be regarded as potential therapeutic targets.

Transforming growth factor beta as a therapeutic target in systemic sclerosis

Transforming growth factor beta (TGF-beta) is a pleiotropic cytokine with vital homeostatic functions. Aberrant TGF-beta expression is implicated in the pathogenesis of fibrosis in systemic sclerosis (SSc); thus, TGF-beta represents a molecular therapeutic target in this disease. Anti-TGF-beta monoclonal antibody has been evaluated in a small trial of early SSc, with disappointing results. Antibodies against the alphavbeta6 integrin that prevent latent TGF-beta activation, however, have shown promise in preclinical studies. Small-molecule inhibitors of TGF-beta-receptor activity are effective in animal models of fibrosis. Imatinib mesylate and related tyrosine kinase inhibitors also block TGF-beta pathways and abrogate fibrotic responses. The blocking of TGF-beta activity might lead to spontaneous immune activation, epithelial hyperplasia and impaired wound healing. Loss of immune tolerance is a potential concern in an autoimmune disease such as SSc. Novel insights from microarray-based gene expression analyses and studies of genetic polymorphisms in TGF-beta signaling could aid in identifying patients who are most likely to respond to anti-TGF-beta treatment. This intervention promises to have a major impact on the treatment of SSc. Concerns regarding efficacy and safety and whether biomarkers can indicate these features, questions regarding appropriate dosing and timing of therapy, and identification of potential responders are critical challenges ahead.

Systemic inflammatory response and downmodulation of peripheral CD25+Foxp3+ T-regulatory cells in patients undergoing radiofrequency thermal ablation for lung cancer

Radiofrequency thermal ablation (RFTA) is a local tumor-destructing technique that can potentially modulate the host immune response through mechanisms that are not clearly defined. We assessed whether RFTA could affect multiple systemic inflammatory and immunological parameters, including CD25+Foxp+ cells, in patients with primary or metastatic lung tumors. Three days after RFTA, a moderate and temporary systemic inflammatory response developed, as demonstrated by the increase in peripheral neutrophils and monocytes and in plasma levels of proinflammatory chemokines (MIP-1alpha, MIP-1beta, eotaxin, and interleukin[IL]-8) and acute phase reactants (complement C3 and C4, serum amyloid, alpha1 antichymotrypsin, and C-reactive protein). Moreover, we found a concomitant release of the anti-inflammatory factor IL-10. Thirty days after RFTA, a significant reduction in CD25+Foxp3+ counts with an increase in CD4+ T-cell proliferation and number of interferon-gamma-secreting cells was observed. The reduction in CD25+Foxp3+ cells lasted up to 90 days after treatment. The use of RFTA in lung cancer patients has an immunomodulatory activity: it induces a self-limiting systemic inflammation early and later a reduction of circulating CD25+Foxp3+ Tregs. In addition to tumor ablation, downmodulation of this regulatory subset might be an important mechanism involved in the long-term clinical efficacy of RFTA.

Arterial and interstitial remodelling processes in non-specific interstitial pneumonia: systemic sclerosis versus idiopathic

AIMS

To compare septal and vascular matrix remodelling, vascular occlusion, pulmonary function tests and survival between two groups: one with idiopathic non-specific interstitial pneumonia (NSIP) and one with NSIP associated with systemic sclerosis (SSc).

METHODS AND RESULTS

Pulmonary biopsy specimens were examined from 40 patients, 22 with NSIP and 18 with NSIP associated with SSc. The content of septal collagen and elastic fibres, as well as the elastic fibres in the vascular interstitium, were higher in the SSc group (P = 0.01, P = 0.001 and P < 0.0001, respectively). Among pulmonary function tests, the diffusing capacity for carbon monoxide/alveolar volume was affected to a greater extent in the SSc group (59% of the predicted value in SSc and 97% in the idiopathic group). There were no differences in collagen content of the vascular interstitium, arterial occlusion, or survival between the two groups.

CONCLUSIONS

Although the fibrotic process is more intense in the SSc group, it does not affect the prognosis of these patients. Because the elastotic process is higher in the SSc group, this might suggest that autoimmune inflammatory mechanisms affecting the elastic fibre system play a greater role in the pathogenesis and pulmonary remodelling process of SSc NSIP than in idiopathic NSIP.