The MAPKinase Signaling and the Stimulatory Protein-1 (Sp1) Transcription Factor Are Involved in the Phototherapy Effect on Cytokines Secretion from Human Bronchial Epithelial Cells Stimulated with Cigarette Smoke Extract

The present study was aimed to investigate the phototherapy effect with low-level laser on human bronchial epithelial cells activated by cigarette smoke extract (CSE). Phototherapy has been reported to actuate positively for controlling the generation/release of anti-inflammatory and pro-inflammatory mediators from different cellular type activated by distinct stimuli. It is not known whether the IL-8 and IL-10 release from CSE-stimulated human bronchial epithelium (BEAS) cells can be influenced by phototherapy. Human bronchial epithelial cell (BEAS) line was cultured in a medium with CSE and irradiated (660 nm) at 9 J. Apoptosis index was standardized with Annexin V and the cellular viability was evaluated by MTT. IL-8, IL-10, cAMP, and NF-κB were measured by ELISA as well as the Sp1, JNK, ERK1/2, and p38MAPK. Phototherapy effect was studied in the presence of mithramycin or the inhibitors of JNK or ERK. The IL-8, cAMP, NF-κB, JNK, p38, and ERK1/2 were downregulated by phototherapy. Both the JNK and the ERK inhibitors potentiated the phototherapy effect on IL-8 as well as on cAMP secretion from BEAS. On the contrary, IL-10 and Sp1 were upregulated by phototherapy. The mithramycin blocked the phototherapy effect on IL-10. The results suggest that phototherapy has a dual effect on BEAS cells because it downregulates the IL-8 secretion by interfering with CSE-mediated signaling pathways, and oppositely upregulates the IL-10 secretion through of Sp1 transcription factor. The manuscript provides evidence that the phototherapy can interfere with MAPK signaling via cAMP in order to attenuate the IL-8 secretion from CSE-stimulated BEAS. In addition, the present study showed that phototherapy effect is driven to downregulation of the both the IL-8 and the ROS secretion and at the same time the upregulation of IL-10 secretion. Besides it, the increase of Sp-1 transcription factor was crucial for laser effect in upregulating the IL-10 secretion. The dexamethasone corticoid produces a significant inhibitory effect on IL-8 as well as ROS secretion, but on the other hand, the corticoid blocked the IL-10 secretion. Taking it into consideration, it is reasonable to suggest that the beneficial effect of laser therapy on lung diseases involves its action on unbalance between pro-inflammatory and anti-inflammatory mediators secreted by human bronchial epithelial cells through different signaling pathway.

Oral feeding with probiotic Lactobacillus rhamnosus attenuates cigarette smoke-induced COPD in C57Bl/6 mice: Relevance to inflammatory markers in human bronchial epithelial cells

COPD is a prevalent lung disease with significant impacts on public health. Affected airways exhibit pulmonary neutrophilia and consequent secretion of pro-inflammatory cytokines and proteases, which result in lung emphysema. Probiotics act as nonspecific modulators of the innate immune system that improve several inflammatory responses. To investigate the effect of Lactobacillus rhamnosus (Lr) on cigarette smoke (CS)-induced COPD C57Bl/6 mice were treated with Lr during the week before COPD induction and three times/week until euthanasia. For in vitro assays, murine bronchial epithelial cells as well as human bronchial epithelial cells exposed to cigarette smoke extract during 24 hours were treated with Lr 1 hour before CSE addition. Lr treatment attenuated the inflammatory response both in the airways and lung parenchyma, reducing inflammatory cells infiltration and the production of pro-inflammatory cytokines and chemokines. Also, Lr-treated mice presented with lower metalloproteases in lung tissue and lung remodeling. In parallel to the reduction in the expression of TLR2, TLR4, TLR9, STAT3, and NF-κB in lung tissue, Lr increased the levels of IL-10 as well as SOCS3 and TIMP1/2, indicating the induction of an anti-inflammatory environment. Similarly, murine bronchial epithelial cells as well as human bronchial epithelial cells (BEAS) exposed to CSE produced pro-inflammatory cytokines and chemokines, which were inhibited by Lr treatment in association with the production of anti-inflammatory molecules. Moreover, the presence of Lr also modulated the expression of COPD-associated transcription found into BALF of COPD mice group, i.e., Lr downregulated expression of NF-κB and STAT3, and inversely upregulated increased expression of SOCS3. Thus, our findings indicate that Lr modulates the balance between pro- and anti-inflammatory cytokines in human bronchial epithelial cells upon CS exposure and it can be a useful tool to improve the lung inflammatory response associated with COPD.

Oral feeding of Lactobacillus bulgaricus N45.10 inhibits the lung inflammation and airway remodeling in murine allergic asthma: Relevance to the Th1/Th2 cytokines and STAT6/T-bet

Asthma is a chronic disease with impacts on public health. It affects the airways causing pulmonary inflammation mediated by CD4 T cells type Th2, eosinophilia, mucus hypersecretion, and elevated IgE. The unbalance between cytokines and transcription factors is an important feature in asthma. Probiotics has gaining highlight as a therapy for chronic diseases. Thus, we investigate the Lactobacillus bulgaricus (Lb) effect in murine allergic asthma. BALB/c-mice were sensitized to ovalbumin (OA) on days 0 and 7 and were challenged from day 14-28 with OA. Mice received Lb seven days prior to sensitization and it was kept until day 28. The Lb attenuated the eosinophils infiltration, mucus and collagen secretion, IgE production, pro-inflammatory cytokines, TLR4 expression, GATA3, STAT6 and RORγt in lung. Otherwise, Lb increased the anti-inflammatory cytokines, the T-bet and foxp3. Finally, Lb attenuated the allergic asthma-induced inflammation and airway remodeling by interfering on Th1/Th2 cytokines and STAT6/T-bet transcription factors.

Beneficial effect of low-level laser therapy in acute lung injury after i-I/R is dependent on the secretion of IL-10 and independent of the TLR/MyD88 signaling

The use of low-level laser for lung inflammation treatment has been evidenced in animal studies as well as clinical trials. The laser action mechanism seems to involve downregulation of neutrophil chemoattractants and transcription factors. Innate immune responses against microorganisms may be mediated by toll-like receptors (TLR). Intestinal ischemia and reperfusion (i-I/R) lead to bacterial product translocation, such as endotoxin, which consequently activates TLRs leading to intestinal and lung inflammation after gut trauma. Thus, the target of this study was to investigate the role of TLR activation in the laser (660 nm, 30 mW, 67.5 J/cm², 0.375 mW/cm², 5.4 J, 180 s, and spot size with 0.08 cm²) effect applied in contact with the skin on axillary lymph node in lung inflammation induced by i-I/R through a signaling adaptor protein known as myeloid differentiation factor 88 (MyD88). It is a quantitative, experimental, and laboratory research using the C57Bl/6 and MyD88^-/- mice (n = 6 mice for experimental group). Statistical differences were evaluated by ANOVA and the Tukey-Kramer multiple comparisons test to determine differences among groups. In order to understand how the absence of MyD88 can interfere in the laser effect on lung inflammation, MyD88^-/- mice were treated or not with laser and subjected to occlusion of the superior mesenteric artery (45 min) followed by intestinal reperfusion (4 h). In summary, the laser decreased the MPO activity and the lung vascular permeability, thickened the alveolar septa, reduced both the edema and the alveolar hemorrhage, as well as significantly decreased neutrophils infiltration in MyD88-deficient mice as well in wild-type mice. It noted a downregulation in chemokine IL-8 production as well as a cytokine IL-10 upregulation in these animals. The results also evidenced that in absence of IL-10, the laser effect is reversed. Based on these results, we suggest that the beneficial effect of laser in acute lung injury after i-I/R is dependent on the secretion of IL-10 and independent of the TLR/MyD88 signaling.

Inflammatory platelet-activating factor-like phospholipids in oxidized low density lipoproteins are fragmented alkyl phosphatidylcholines

Oxidation of human low density lipoprotein (LDL) generates proinflammatory mediators and underlies early events in atherogenesis. We identified mediators in oxidized LDL that induced an inflammatory reaction in vivo, and activated polymorphonuclear leukocytes and cells ectopically expressing human platelet-activating factor (PAF) receptors. Oxidation of a synthetic phosphatidylcholine showed that an sn-1 ether bond confers an 800-fold increase in potency. This suggests that rare ether-linked phospholipids in LDL are the likely source of PAF-like activity in oxidized LDL. Accordingly, treatment of oxidized LDL with phospholipase A(1) greatly reduced phospholipid mass, but did not decrease its PAF-like activity. Tandem mass spectrometry identified traces of PAF, and more abundant levels of 1-O-hexadecyl-2-(butanoyl or butenoyl)-sn-glycero-3-phosphocholines (C(4)-PAF analogs) in oxidized LDL that comigrated with PAF-like activity. Synthesis showed that either C(4)-PAF was just 10-fold less potent than PAF as a PAF receptor ligand and agonist. Quantitation by gas chromatography-mass spectrometry of pentafluorobenzoyl derivatives shows the C(4)-PAF analogs were 100-fold more abundant in oxidized LDL than PAF. Oxidation of synthetic alkyl arachidonoyl phosphatidylcholine generated these C(4)-PAFs in abundance. These results show that quite minor constituents of the LDL phosphatidylcholine pool are the exclusive precursors for PAF-like bioactivity in oxidized LDL.