Interferon-gamma 1b: impact of new indications (idiopathic pulmonary fibrosis)

Cytokine Receptor Profiling in Human Colonic Subepithelial Myofibroblasts: A Differential Effect of Th Polarization-Associated Cytokines in Intestinal Fibrosis

BACKGROUND

Colonic subepithelial myofibroblasts (cSEMFs) are mesenchymal cells with a pivotal role in the pathophysiology of Crohn's disease (CD) fibrosis. Here, we demonstrate for the first time a complete expression mapping of cytokine receptors, implicated in inflammatory bowel diseases, in primary human cSEMFs and how pro-inflammatory cytokines regulate this expression. Furthermore, we show the effect of Th1-, Th2-, Th17- and Treg-related cytokines on a fibrosis-related phenotype of cSEMFs.

METHODS

Colonic subepithelial myofibroblasts were isolated from healthy individuals' colonic biopsies. Interleukin (IL)-1α- and/or tumor necrosis factor (TNF)-α-induced mRNA and protein expression of cytokine receptors was assayed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunofluorescence, respectively. Th-related cytokine effects on mRNA and protein profibrotic factor expression were analyzed by qRT-PCR and/or colorimetric assays and on the wound-healing capacity of cSEMFs by scratch test.

RESULTS

In cSEMFs, we observed basal cytokine receptor expression, which was modified by IL-1α and TNF-α. Th1-related cytokines upregulated tissue factor (TF), collagen, fibronectin and matrix metalloproteinase (MMP)-1 and downregulated α-smooth muscle actin (α-SMA), MMP-9, and wound healing rate. Th2-related cytokines upregulated collagen, TF, α-SMA, MMP-1, and wound healing rate and downregulated fibronectin and MMP-9. IL-17 and IL-23 upregulated fibronectin, and IL-22 downregulated TF. IL-17 and IL-22 decreased wound healing rate. Similar to TGF-β, IL-23 upregulated MMP-1, tissue inhibitor of metalloproteinases-1, collagen expression, and wound healing rates.

CONCLUSIONS

Our results suggest that cSEMFs have a central role in inflammation and fibrosis, as they express a great variety of Th-related cytokine receptors, making them responsive to pro-inflammatory cytokines, abundant in the inflamed mucosa of CD patients.

Paeoniflorin, the main active constituent of Paeonia lactiflora roots, attenuates bleomycin-induced pulmonary fibrosis in mice by suppressing the synthesis of type I collagen

ETHNOPHARMACOLOGICAL RELEVANCE

In the theory of traditional Chinese medicine, pulmonary fibrosis (PF) belongs to pulmonary arthralgia, which means blood stasis in lung tissue. The roots of Paeonia lactiflora Pall are usually used to relieve the symptoms of this disease by promoting blood circulation and removing blood stasis. Paeoniflorin, the main active ingredient of P. lactiflora, may have anti-PF potential.

AIM OF STUDY

This study aimed to investigate the effects and underlying mechanisms of paeoniflorin on bleomycin (BLM)-induced PF in mice.

MATERIALS AND METHODS

The PF model was established in mice by an intratracheal instillation of BLM. Paeoniflorin (25, 50, 100mg/kg) and prednisone (6mg/kg), as a positive control, were orally administered for consecutive 21 days. Histopathological changes were evaluated by hematoxylin and eosin stain and Masson's trichrome stain. The content of hydroxyproline was detected by using kits. The contents of type I collagen, TGF-β1 and IFN-γ were detected by ELISA. The levels of α-SMA, Smad4, Smad7 and the phosphorylations of Smad2/3 were detected by western blot. The mRNA expressions of MMP-1 and TIMP-1 were detected by RT-PCR.

RESULTS

In mice treated with BLM, paeoniflorin (50mg/kg) significantly prolonged the survival periods, attenuated infiltration of inflammatory cells, interstitial fibrosis, and deposition of extracellular matrix in lung tissues. It also decreased the contents of hydroxyproline (a marker of collagens), type I collagen and α-SMA (an indicator of myofibroblasts) in lung tissues of mice. Paeoniflorin down-regulated the expressions of TGF-β1, Smad4 and the phosphorylations of Smad2/3, while up-regulated the expression of Smad7 in lung tissues. Moreover, paeoniflorin increased the content of IFN-γ. But, it only slightly affected mRNA expressions of MMP-1 and TIMP-1 in lung tissues of mice.

CONCLUSIONS

Paeoniflorin attenuates PF by suppressing type I collagen synthesis via inhibiting the activation of TGF-β/Smad pathway and increasing the expression of IFN-γ.

Antifibrotic action of pirfenidone and prednisolone: different effects on pulmonary cytokines and growth factors in bleomycin-induced murine pulmonary fibrosis

Pirfenidone, a broad-spectrum antifibrotic agent, is known to have efficacy in certain fibrotic disease models, and is under clinical trials in patients with idiopathic pulmonary fibrosis. We investigated the antifibrotic effect of pirfenidone, and its regulatory effect on various pulmonary cytokines, in bleomycin-induced lung fibrosis in mice at the protein level, using prednisolone as a reference agent. Pirfenidone attenuated the bleomycin-induced pulmonary fibrosis at a minimum effective dose of 30 mg/kg/day t.i.d. from the analysis of lung hydroxyproline content. Both pirfenidone (30, 100 mg/kg/day t.i.d) and prednisolone (3, 15 mg/kg/day q.d.) suppressed lung inflammatory edema; however, prednisolone failed to suppress pulmonary fibrosis, which was significantly suppressed only by pirfenidone. Both pirfenidone and prednisolone suppressed the increase in lung interleukin (IL)-1beta, IL-6, IL-12p40 and monocyte chemoattractant protein (MCP)-1 levels induced by bleomycin. On the other hand, pirfenidone prevented the bleomycin-induced decrease in lung interferon (IFN)-gamma levels, while prednisolone had no such effect. Furthermore, pirfenidone suppressed elevation of lung basic-fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta1 levels, but prednisolone had no such effect. The increases in lung stroma cell derived factor (SDF)-1alpha and IL-18 were also suppressed. These findings suggest that pirfenidone exerts its antifibrotic effect through regulation of lung IFN-gamma, bFGF and TGF-beta1 levels during the development of bleomycin-induced pulmonary fibrosis in mice. The effect on SDF-1alpha and IL-18 levels may also be related to the antifibrotic effects of pirfenidone.

Mechanistically identified suitable biomarkers of exposure, effect, and susceptibility for silicosis and coal-worker's pneumoconiosis: a comprehensive review

Clinical detection of silicosis is currently dependent on radiological and lung function abnormalities, both late manifestations of disease. Markers of prediction and early detection of pneumoconiosis are imperative for the implementation of timely intervention strategies. Understanding the underlying mechanisms of the etiology of coal workers pneumoconiosis (CWP) and silicosis was essential in proposing numerous biomarkers that have been evaluated to assess effects following exposure to crystalline silica and/or coal mine dust. Human validation studies have substantiated some of these proposed biomarkers and argued in favor of their use as biomarkers for crystalline silica- and CWP-induced pneumoconiosis. A number of "ideal" biological markers of effect were identified, namely, Clara cell protein-16 (CC16) (serum), tumor necrosis factor-alpha (TNF-alpha) (monocyte release), interleukin-8 (IL-8) (monocyte release), reactive oxygen species (ROS) measurement by chemiluminescence (neutrophil release), 8-isoprostanes (serum), total antioxidant levels measured by total equivalent antioxidant capacity (TEAC), glutathione, glutathione peroxidase activity, glutathione S-transferase activity, and platelet-derived growth factor (PDGF) (serum). TNF-alpha polymorphism (blood cellular DNA) was identified as a biomarker of susceptibility. Further studies are planned to test the validity and feasibility of these biomarkers to detect either high exposure to crystalline silica and early silicosis or susceptibility to silicosis in gold miners in South Africa.

Bronchoalveolar lavage cytokine profile in a cohort of lung transplant recipients: A predictive role of interleukin-12 with respect to onset of bronchiolitis obliterans syndrome

BACKGROUND

Bronchiolitis obliterans syndrome is the main long-term complication of lung transplantation that limits survival of lung transplant patients. Its pathophysiologic mechanisms are still poorly understood but it seems to result from a chronic immunologic/inflammatory insult leading to excessive fibroproliferation. The aim of this longitudinal study of 44 lung recipients was to determine whether a number of bronchoalveolar lavage and clinical variables are associated with a higher risk of developing bronchiolitis obliterans syndrome.

METHODS

Bronchoalveolar lavage studies involved assessment of several cytokines including: interleukin-8, monocyte chemoattractant protein-1, regulated-upon-activation normal T cell expressed and secreted (RANTES), gamma-interferon, interleukin-12, interleukin-10 and transforming growth factor-beta.

RESULTS

The predictivity of bronchoalveolar lavage (BAL) features with respect to onset of bronchiolitis obliterans syndrome was assessed by the Cox regression model. Among clinical variables, bacterial and viral infections were found to significantly predict occurrence of bronchiolitis obliterans syndrome (hazard ratio [HR] for bacterial infection: 13.044, 95% confidence interval [CI] 1.34 to 126.69, p = 0.027; HR for viral infections: 4.88, 95% CI 1.004 to 22.87, p = 0.05). Among BAL variables, only IL-12 was significantly predictive of bronchiolitis obliterans syndrome (HR 0.956, 95% CI 0.901 to 1.01, p = 0.03). In addition, in a sub-group cross-sectional analysis, bronchiolitis obliterans syndrome patients were compared with clinically stable patients, and significant increases in median levels of interleukin-8 and monocyte chemoattractant protein-1 BAL fluid were detected.

CONCLUSIONS

These findings support the contention that interleukin-12 plays a role in the modulation of the local pro-/anti-fibrotic balance of allograft airways.