TNF and ROS Crosstalk in Inflammation

Serum Cytokinome Profile Evaluation: A Tool to Define New Diagnostic and Prognostic Markers of Cancer Using Multiplexed Bead-Based Immunoassays

In recent years, many researchers are focusing their attention on the link between inflammation and cancer. The inflammation is involved in the tumor development and suppression, by stimulating the immune response. In particular, the transition from chronic inflammation to cancer produces angiogenic and growth factors able to repair the tissue and to promote cancer cell survival, implantation, and growth. In this contest, the cytokines contribute to the development of these processes becoming active before and during the inflammatory process and playing an important function at the various disease levels. Thus, these proteins can represent specific markers of tumor development and progression. Therefore the "cytokinome" term is used to indicate the evaluation of cytokine pattern by using an "omics" approach. Newly, specific protein chips of considerable and improved sensitivity are being developed to determine simultaneously several and different cytokines. This can be achieved by a multiplex technology that, through the use of small amounts of serum or other fluids, is used to determine the presence and the levels of underrepresented cytokines. Since this method is an accurate, sensitive, and reproducible cytokine assay, it is already used in many different studies. Thus, this review focuses on the more latest aspects related to cytokinome profile evaluation in different cancers.

The protection effect of LEAP-2 on the mudskipper (Boleophthalmus pectinirostris) against Edwardsiella tarda infection is associated with its immunomodulatory activity on monocytes/macrophages

Liver-expressed antimicrobial peptide 2 (LEAP-2) is a cationic peptide that plays an important role in the host's innate immune system. However, the mechanism by which LEAP-2 modulates/regulates the host defense against pathogens remains largely unknown. In this study, we identified a cDNA sequence encoding LEAP-2 homolog (BpLEAP-2) in the mudskipper, Boleophthalmus pectinirostris. Sequence analysis revealed that BpLEAP-2 belonged to the fish LEAP-2A cluster and that it was closely related to ayu LEAP-2. BpLEAP-2 mRNA was detected in a wide range of tissues, with the highest level of transcripts found in the liver. Upon infection with Edwardsiella tarda, BpLEAP-2 mRNA expression was significantly increased in the liver, kidney, spleen, and gill, but decreased in the intestine. Chemically synthesized BpLEAP-2 mature peptide did not exhibit antibacterial activity against E. tarda in vitro. Intraperitoneal injection of BpLEAP-2 (1.0 or 10.0 μg/g) resulted in significantly improved survival rate and reduced tissue bacterial load in E. tarda-infected mudskippers. In E. tarda-infected fish, BpLEAP-2 (0.1, 1.0, or 10.0 μg/g) eliminated E. tarda-induced tissue mRNA expression of BpTNF-α and BpIL-1β. In monocytes/macrophages (MO/MФ), BpLEAP-2 (1.0 or 10.0 μg/ml) induced chemotaxis, enhanced respiratory burst, and inhibited E. tarda-induced mRNA expression of BpTNF-α and BpIL-1β. At a concentration of 10.0 μg/ml, BpLEAP-2 also significantly enhanced the bacterial killing efficiency of MO/MФ. No significant effect was seen in the phagocytic activity of MO/MФ upon treatment with BpLEAP-2. Our study provides evidence, for the first time, that LEAP-2 exhibited immunomodulatory effects on immune cells, and protected the host from pathogenic infections independent of direct bacterial killing function.

Ionizing radiation promotes CCL27 secretion from keratinocytes through the cross talk between TNF-α and ROS

The skin-associated chemokine CCL27 and its receptor CCR10 mediate the immune response of skin-homing T cells. The CCL27 secreted from keratinocytes was reportedly involved in inflammatory skin diseases such as atopic dermatitis, contact dermatitis, and psoriasis. However, whether ionizing radiation increases the levels of CCL27 secretion still remains unclear. In HaCaT cells, a human keratinocyte cell line, CCL27 secretion was markedly increased after X-ray irradiation. We further found that irradiation boosted the generation of reactive oxygen species (ROS), which was concomitant with the release of tumor necrosis factor-alpha (TNF-α). Moreover, alteration of ROS in irradiated HaCaT cells correlated with TNF-α secretion, indicating a positive loop of TNF-α secretion and ROS generation. This positive loop regulated the secretion of CCL27 from irradiated cells. We therefore concluded that the cross talk between TNF-α and ROS after keratinocytes was exposed to radiation, triggered CCL27 secretion for subsequent inflammation response.

Securinine from Phyllanthus glaucus Induces Cell Cycle Arrest and Apoptosis in Human Cervical Cancer HeLa Cells

Background

The Securinega-type alkaloids occur in plants belonging to Euphorbiaceae family. One of the most widely distributed alkaloid of this group is securinine, which was identified next to allosecurinine in Phyllanthus glaucus (leafflower). Recently, some Securinega-type alkaloids have paid attention to its antiproliferative potency towards different cancer cells. However, the cytotoxic properties of allosecurinine have not yet been evaluated.

Methods

The cytotoxicity of the extract, alkaloid fraction obtained from P. glaucus, isolated securinine and allosecurinine against HeLa cells was evaluated by real-time xCELLigence system and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected by annexin V and 7-amino-actinomycin (7-AAD) staining and confirmed with fluorescent Hoechst 33342 dye. The assessment of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation, the level of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), caspase-3/7 activity and cell cycle analysis were measured by flow cytometry. The enzymatic activity of caspase-9 was assessed by a luminometric assay. The expression of apoptosis associated genes was analyzed by real-time PCR.

Results

The experimental data revealed that securinine and the alkaloid fraction were significantly potent on HeLa cells growth inhibition with IC₅₀ values of 7.02 ± 0.52 μg/ml (32.3 μM) and 25.46 ± 1.79 μg/ml, respectively. The activity of allosecurinine and Phyllanthus extract were much lower. Furthermore, our study showed that the most active securinine induced apoptosis in a dose-dependent manner in the tested cells, increased the percentage of ROS positive cells and depolarized cells as well as stimulated the activity of ERK1/2, caspase-9 and -3/7. Securinine also induced cell cycle arrest in S phase. Real-time PCR analysis showed high expression of TNFRSF genes in the cells stimulated with securinine.

Conclusions

Securinine induces apoptosis and activates cell cycle checkpoints in HeLa cells which is associated with oxidative stress. The results indicate that the mitochondrial pathway is involved in the programmed cell death.

Functional Differences In Gingival Fibroblasts Obtained from Young and Elderly Individuals

Abstract Fibroblasts participate in the wound repair process through proliferation and migration as well as the synthesis of factors growth and extracellular matrix molecules. However, cell aging and the individual himself can lead to reduction of cell functions and consequently, the ability of tissue repair. This study evaluated the activity of gingival fibroblasts from young (Y) and elderly (Y) patients and their responsiveness to tumor necrosis factor alpha (TNF-a). Gingival fibroblasts were isolated from six patients (3Y; and 3E) and seeded in complete culture medium (DMEM). For cell viability analysis, total protein production and collagen synthesis, fibroblasts were cultured in 96-well plates for 24, 48 or 72 h (n=36). Cell responses to TNF-a, was evaluated by application of this cytokine to cultured cells (100 ng/mL) for 24 h, followed by evaluation of reactive oxygen species (ROS), nitric oxide (NO) and CCL5 production (n=36). Data were analyzed by Kruskal-Wallis and the Mann-Whitney U tests (a = 0.05). Viability of E fibroblasts was higher than Y fibroblasts for 24 and 48 h, but these cells showed gradual reduction of viability over the course of time. For Y cells, reduced collagen synthesis was observed at 48 h. No difference was observed in ROS production for both cells after TNF-a exposure. However, both cultures showed increased production of NO and CCL5 in the presence of TNF-a. Functional differences and distinct responsiveness to TNF-a were observed according to patient's age.

Activation of apoptosis signalling pathways by reactive oxygen species

Reactive oxygen species (ROS) are short-lived and highly reactive molecules. The generation of ROS in cells exists in equilibrium with a variety of antioxidant defences. At low to modest doses, ROS are considered to be essential for regulation of normal physiological functions involved in development such as cell cycle progression and proliferation, differentiation, migration and cell death. ROS also play an important role in the immune system, maintenance of the redox balance and have been implicated in activation of various cellular signalling pathways. Excess cellular levels of ROS cause damage to proteins, nucleic acids, lipids, membranes and organelles, which can lead to activation of cell death processes such as apoptosis. Apoptosis is a highly regulated process that is essential for the development and survival of multicellular organisms. These organisms often need to discard cells that are superfluous or potentially harmful, having accumulated mutations or become infected by pathogens. Apoptosis features a characteristic set of morphological and biochemical features whereby cells undergo a cascade of self-destruction. Thus, proper regulation of apoptosis is essential for maintaining normal cellular homeostasis. ROS play a central role in cell signalling as well as in regulation of the main pathways of apoptosis mediated by mitochondria, death receptors and the endoplasmic reticulum (ER). This review focuses on current understanding of the role of ROS in each of these three main pathways of apoptosis. The role of ROS in the complex interplay and crosstalk between these different signalling pathways remains to be further unravelled during the coming years.

Allergy-specific Phenome-Wide Association Study for Immunogenes in Turkish Children

To dissect the role of immunogenetics in allergy and asthma, we performed a phenome-wide association study in 974 Turkish children selected from a cross-sectional study conducted using ISAAC (International Study of Asthma and Allergies in Children) Phase II tools. We investigated 9 loci involved in different immune functions (ADAM33, ADRB2, CD14, IL13, IL4, IL4R, MS4A2, SERPINE1, and TNF) with respect to 116 traits assessed through blood tests, hypertonic saline challenge tests, questionnaires, and skin prick tests. Multiple associations were observed for ADAM33: rs2280090 was associated with reduced MEF240% (i.e., the ratio of Mean Expiratory Flow after 240s of hypertonic saline inhalation with respect to the age- and ancestry-matched reference value) and with an increased risk of allergic bronchitis (p = 1.77*10⁻⁴ and p = 7.94*10⁻⁴, respectively); rs3918396 was associated with wheezing and eczema comorbidity (p = 3.41*10⁻⁴). IL4 rs2243250 was associated with increased FEV240 (Forced Expiratory Flow Volume after 240s of hypertonic saline inhalation; p = 4.81*10⁻⁴) and CD14 rs2569190 was associated with asthma diagnosis (p = 1.36*10⁻³). ADAM33 and IL4 appeared to play a role in the processes linked to allergic airway inflammation and lung function. Due to its association with wheezing and eczema comorbidity, ADAM33 may also be involved in the atopic march.

(-)-Epicatechin improves insulin sensitivity in high fat diet-fed mice

Obesity constitutes a major public health concern, being frequently associated with type 2 diabetes (T2D). Evidence from studies in humans and experimental animals suggest that consumption of the flavan-3-ol (-)-epicatechin (EC) and of EC-rich foods may improve insulin sensitivity. To further understand the potential benefits of dietary EC consumption on insulin resistance, this study investigated the capacity of EC supplementation to prevent high fat diet (HFD)-induced insulin resistance in mice. To assess the underlying mechanisms, the effects of HFD and EC consumption on the activation of the insulin cascade and of its negative modulators were evaluated. HFD consumption for 15 w caused obesity and insulin resistance in C57BL/6J mice as evidenced by high fasted and fed plasma glucose and insulin levels, and impaired ITT and GTT tests. This was associated with alterations in the activation of components of the insulin-triggered signaling cascade (insulin receptor, IRS1, ERK1/2, Akt) in adipose and liver tissues. EC supplementation prevented/ameliorated all these parameters. EC acted improving insulin sensitivity in the HFD-fed mice in part through a downregulation of the inhibitory molecules JNK, IKK, PKC and protein tyrosine phosphatase 1B (PTP1B). Thus, the above results suggest that consumption of EC-rich foods could constitute a dietary strategy to mitigate obesity-associated insulin resistance.