Immunoexpression of TGF-β/Smad and VEGF-A proteins in serum and BAL fluid of sarcoidosis patients

The immunoregulatory role of IL-35 in patients with interstitial lung disease

Pulmonary fibrosis involves various types of immune cells and soluble mediators, including TGF-β and IL-35, a recently identified heterodimeric cytokine that belongs to the IL-12 cytokine family. However, the effect of regulatory IL-35 may play an important role in fibrotic diseases. The aim of this paper is to explore the immunoregulatory role of IL-35 in the development of fibrosis in interstitial lung disease (ILD). To gain a better understanding of this issue, the concentrations of IL-35 and different profibrotic cytokines in fibrotic (F-ILD) and non-fibrotic (NF-ILD) patients by ELISA were compared to that of intracellular IL-35 and IL-17 on CD4+ T cells stimulated in the presence of BAL or with different ratios of recombinant IL-35 (rIL-35) and TGF-β (rTGF-β), which were evaluated by flow cytometry. We observed that BAL concentration of IL-35 was lower in F patients (p < 0.001) and was negatively correlated with concentrations of TGF-β (p < 0.001) and IL-17 (p < 0.001). In supplemented cell cultures, BAL from NF but not F patients enhanced the percentage of IL-35 + CD4+ T (p < 0.001) cells and decreased the percentage of IL-17 + CD4+ T cells (p < 0.001). The percentage of IL-35 + CD4+ T cells correlated positively with BAL concentration of IL-35 (p = 0.02), but correlated negatively with BAL concentrations of IL-17 (p = 0.007) and TGF-β (p = 0.01). After adjusting the concentrations of recombinant cytokines to establish a TGF-β: IL-35 ratio of 1:4, an enhanced percentage of IL-35 + CD4+ T cells (p < 0.001) but a decreased percentage of IL-17 + CD4+ T cells (p < 0.001) was observed. After adding recombinant IL-35 to the BAL from F patients until a 1:4 ratio of TGF-β: IL-35 was reached, a significantly increased percentage of IL-35 + CD4+ T cells (p < 0.001) and a decreased percentage of IL-17 + CD4+ T cells (p = 0.003) was found. These results suggest that IL-35 may induce an anti-fibrotic response, regulating the effect of TGF-β and the inflammatory response on CD4+ T cells. In addition, the TGF-β: IL-35 ratio in BAL has been shown to be a potential biomarker to predict the outcome of F patients with ILD.

Serum amyloid A/anti-CCL20 induced the rebalance of Th17/regulatory T cells in SodA-induced sarcoidosis

Sarcoidosis is a multisystemic granulomatous inflammation associated with Th17/regulatory T cell (Treg) polarization. As a marker of inflammation, serum amyloid A (SAA) could upregulate the expression of chemokine ligand 20 (CCL20), which induces the migration of Treg cells and Th17 cells by binding and activating thechemokine C-C receptor (CCR) 6. Our goal was to determine whether SAA/anti-CCL20 induces Th17/Treg rebalance in pulmonary sarcoidosis. The deposition of SAA- and Th17/Treg-related proteins in SodA-induced granulomas was tested using immunohistochemistry. Mice with SodA-induced sarcoidosis were treated with SAA or SAA + anti-CCL20, and then Th1/Th2 and Th17/Treg cells were detected by fluorescence-activated cell sorting (FACS) analysis. The expression of SAA/CCL20 and IL-23/IL-17A was detected by enzyme-linked immunosorbent assay (ELISA) and multiplex. Key proteins in the TGF-β/Smad signaling pathway were tested by western blot. SAA mainly plays a pro-inflammatory role by promoting the expression of CCL20 and IL-17A in bronchoalveolar lavage fluid (BALF) and serum, exacerbating this elevation of CD4+/CD8+ T cells in both mediastinal lymph nodes (LNs) and BALF, as well as proliferating Th1 in LNs in SodA-induced pulmonary sarcoidosis. In addition, SAA could also promote the proliferation of Tregs in LNs. Intriguingly, blocking of CCL20 could partially reverse the expression of Th17-related cytokine, ameliorate Th1/Th2 and Treg/Th17 bias in mice with SodA-induced pulmonary sarcoidosis, and rescue the overactivation of the TGF-β/Smad2/Smad3 signaling pathway. Anti-CCL20 may have the potential for therapeutic translation, targeting on the immunopathogenesis of pulmonary sarcoidosis.

Identification of the Core MicroRNAs and Potential Molecular Mechanismsin Sarcoidosis Using Bioinformatics Analysis

Sarcoidosis is a systemic heterogeneous inflammatory disease; however, the etiology and pathogenesis of sarcoidosis are still unknown. Herein, we investigated the core microRNAs and potential molecular mechanisms in sarcoidosis. The DE-miRNAs were diagnosed using the LIMMA software package. DIANA-mirPath was employed to perform pathway and GO enrichment analysis of the DE-miRNAs. PPI networks and miRNA-target gene regulatory networks were used to obtain insight into the actions of DE-miRNAs. Expression of the hub genes along with miRNAs was validated in clinical specimens. Overall, 266 DE-miRNAs were screened. Among these DE-miRNAs, hsa-miR-144, hsa-miR-126, as well as hsa-miR-106a were the upmost upregulated miRNAs; hsa-miR-151-3p, hsa-miR-320d, and hsa-miR-324-3p were the top downregulated miRNAs. NR3C1, ZBTB7A, NUFIP2, BZW1, ERGIC2, and VEGFA were mapped as the most targeted hub genes in the upregulation of miRNAs, and MCL1 and SAE1 were the most targeted hub genes in the downregulation of miRNA. VEGFA and NR3C1 were selected and potentially modulated by hsa-miR-20b, hsa-miR-126, and hsa-miR-106a. In sarcoidosis pathological tissue, hsa-miR-126 was highly expressed, and VEGFA and NR3C1 were overexpressed. In conclusion, our results revealed the dysregulation of hsa-miR-126 and a potential regulatory mechanism for pathogenesis in sarcoidosis.

Association of proangiogenic and profibrotic serum markers with lung function and quality of life in sarcoidosis

Background

Sarcoidosis is a systemic inflammatory granulomatous disease, frequently affecting the lung. If left untreated, it may end in lung fibrosis. Proangiogenic and profibrotic vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1, fibroblast growth factor (FGF)-2 and platelet-derived growth factor (PDGF)-AB are a known therapeutical target in pulmonary fibrosing diseases, e.g. IPF, but there is no targeted therapy option for pulmonary fibrosis in sarcoidosis.

Objectives

The aim of our study was to determine the association of these markers’ serum levels on lung function and the patients’ quality of life in a long-term follow-up of sarcoidosis patients, to provide further information for finding targeted therapy options for pulmonary sarcoidosis.

Methods

54 patients with sarcoidosis underwent blood sampling, pulmonary function testing and answered the King’s Brief Interstitial Lung Disease (K-BILD) questionnaire at baseline and at three-years follow-up. Serum levels of profibrotic and angiogenic markers were assessed at baseline by enzyme-linked immunosorbent assay.

Results

Between 2015 and 2018, 54 patients with biopsy proven sarcoidosis were enrolled. Throughout the observation period, there was a significant decrease in the diffusion capacity for carbon monoxide (DLCO) [%] (-6.5504 ± 13,39, p = 0.001) and forced expiratory volume in one second predicted (FEV1) [%] (-6.07 ± 12.09, p = 0.001). Patients with greater impairment of forced vital capacity (FVC) did have significantly higher serum levels of VEGF (p = 0.03) and PDGF-AB (p<0.001). The K-BILD questionnaire did not change significantly during follow-up. However, patients with worsening K-BILD scores did have significantly higher serum-levels of PDGF-AB (2.67 pg/ml ± 0.93 vs. 1.88 pg/ml ± 0.60, p = 0.004) at baseline, compared to those with unchanged or increasing K-BILD scores.

Conclusions

Among patients with pulmonary sarcoidosis, baseline serum levels of VEGF and PDGF-AB were associated with pulmonary function impairment. Furthermore, PDGF-AB was associated with worsening K-BILD scores. No such association was observed for FGF-2 and TGF-ß1. VEGF and PDGF-AB may be possible prognostic and therapeutic targets in sarcoidosis as a fibrosing ILD beyond IPF.

Subacute TGFβ expression drives inflammation, goblet cell hyperplasia, and pulmonary function abnormalities in mice with effects dependent on CFTR function

Cystic fibrosis (CF) produces variable lung disease phenotypes that are, in part, independent of the CF transmembrane conductance regulator ( CFTR) genotype. Transforming growth factor-β (TGFβ) is the best described genetic modifier of the CF phenotype, but its mechanism of action is unknown. We hypothesized that TGFβ is sufficient to drive pathognomonic features of CF lung disease in vivo and that CFTR deficiency enhances susceptibility to pathological TGFβ effects. A CF mouse model and littermate controls were exposed intratracheally to an adenoviral vector containing the TGFβ1 cDNA (Ad-TGFβ), empty vector, or PBS only. Studies were performed 1 wk after treatment, including lung mechanics, collection of bronchoalveolar lavage fluid, and analysis of lung histology, RNA, and protein. CF and non-CF mice showed similar weight loss, inflammation, goblet cell hyperplasia, and Smad pathway activation after Ad-TGFβ treatment. Ad-TGFβ produced greater abnormalities in lung mechanics in CF versus control mice, which was uniquely associated with induction of phosphoinositide 3-kinase and mitogen-activated protein kinase signaling. CFTR transcripts were reduced, and epithelial sodium channel transcripts were increased in CF and non-CF mice, whereas the goblet cell transcription factors, forkhead ortholog A3 and SAM-pointed domain-containing ETS-like factor, were increased in non-CF but not CF mice following Ad-TGFβ treatment. Pulmonary TGFβ1 expression was sufficient to produce pulmonary remodeling and abnormalities in lung mechanics that were associated with both shared and unique cell signaling pathway activation in CF and non-CF mice. These results highlight the multifunctional impact of TGFβ on pulmonary pathology in vivo and identify cellular-response differences that may impact CF lung pathology.

Expression, purification and functionality of bioactive recombinant human vascular endothelial growth factor VEGF165 in E. coli

Vascular endothelial growth factor (VEGF) is associated with tumour growth and metastasis. Because VEGF is the major player in both angiogenesis and vascular permeability and the most explored factor in angio-inhibitory therapies, many expression procedures have been developed to produce functional VEGF₁₆₅ in convenient yield. In this study, recombinant human VEGF₁₆₅ was cloned and expressed in Escherichia coli (BL21)-DE3 cells and large scale production was performed by fermentation. A high yield of active soluble protein was obtained after protein extraction employing both lysozyme and sonication treatment. Inclusion bodies were also isolated from the cell lysate and subjected to a simple protocol of solubilisation and refolding. Single-step purification was performed using nickel affinity chromatography and the purified proteins were able to recognize monoclonal Anti-poly-His antibody. The biological activity of the VEGF₁₆₅ was successfully tested using the Chicken chorioallantoic membrane assay, wound-healing migration and proliferation assay on human umbilical vein endothelial cells (HUVEC).

Expression Profile of Six RNA-Binding Proteins in Pulmonary Sarcoidosis

BACKGROUND

Sarcoidosis is characterised by up-regulation of cytokines and chemokine ligands/receptors and proteolytic enzymes. This pro-inflammatory profile is regulated post-transcriptionally by RNA-binding proteins (RBPs). We investigated in vivo expression of six RBPs (AUF1, HuR, NCL, TIA, TIAR, PCBP2) and two inhibitors of proteolytic enzymes (RECK, PTEN) in pulmonary sarcoidosis and compared it to the expression in four control groups of healthy individuals and patients with other respiratory diseases: chronic obstructive pulmonary disease (COPD), asthma and idiopathic interstitial pneumonias (IIPs).

METHODS

RT-PCR was used to quantify the mRNAs in bronchoalveolar (BA) cells obtained from 50 sarcoidosis patients, 23 healthy controls, 30 COPD, 19 asthmatic and 19 IIPs patients. Flow cytometry was used to assess intracellular protein expression of AUF1 and HuR in peripheral blood T lymphocytes (PBTLs) obtained from 9 sarcoidosis patients and 6 healthy controls.

RESULTS

Taking the stringent conditions for multiple comparisons into consideration, we consistently observed in the primary analysis including all patients regardless of smoking status as well as in the subsequent sub-analysis limited for never smokers that the BA mRNA expression of AUF1 (p<0.001), TIA (p<0.001), NCL (p<0.01) and RECK (p<0.05) was decreased in sarcoidosis compared to healthy controls. TIA mRNA was also decreased in sarcoidosis compared to both obstructive pulmonary diseases (COPD and asthma; p<0.001) but not compared to IIPs. There were several positive correlations between RECK mRNA and RBP mRNAs in BA cells. Also sarcoidosis CD3+, CD4+ and CD8+ PBTLs displayed lower mean fluorescence intensity of AUF1 (p≤0.02) and HuR (p≤0.03) proteins than control healthy PBTLs.

CONCLUSION

mRNA expressions of three RBPs (AUF1, TIA and NCL) and their potential target mRNA encoding RECK in BA cells and additionally protein expression of AUF1 and HuR in PBTLs were down-regulated in our sarcoidosis patients compared to healthy individuals. Its significance, e.g. for stability of mRNAs encoding pro-inflammatory factors, should be further explored in sarcoidosis.