Interleukin-8 secretion by fibroblasts induced by low density lipoproteins is p38 MAPK-dependent and leads to cell spreading and wound closure

Association of Obesity and Severe Asthma in Adults

The incidence of obesity and asthma continues to enhance, significantly impacting global public health. Adipose tissue is an organ that secretes hormones and cytokines, causes meta-inflammation, and contributes to the intensification of bronchial hyperreactivity, oxidative stress, and consequently affects the different phenotypes of asthma in obese people. As body weight increases, the risk of severe asthma increases, as well as more frequent exacerbations requiring the use of glucocorticoids and hospitalization, which consequently leads to a deterioration of the quality of life. This review discusses the relationship between obesity and severe asthma, the underlying molecular mechanisms, changes in respiratory function tests in obese people, its impact on the occurrence of comorbidities, and consequently, a different response to conventional asthma treatment. The article also reviews research on possible future therapies for severe asthma. The manuscript is a narrative review of clinical trials in severe asthma and comorbid obesity. The articles were found in the PubMed database using the keywords asthma and obesity. Studies on severe asthma were then selected for inclusion in the article. The sections: 'The classification connected with asthma and obesity', 'Obesity-related changes in pulmonary functional tests', and 'Obesity and inflammation', include studies on subjects without asthma or non-severe asthma, which, according to the authors, familiarize the reader with the pathophysiology of obesity-related asthma.

AESIS-1, a Rheumatoid Arthritis Therapeutic Peptide, Accelerates Wound Healing by Promoting Fibroblast Migration in a CXCR2-Dependent Manner

In patients with autoimmune disorders such as rheumatoid arthritis (RA), delayed wound healing is often observed. Timely and effective wound healing is a crucial determinant of a patient's quality of life, and novel materials for skin wound repair, such as bioactive peptides, are continuously being studied and developed. One such bioactive peptide, AESIS-1, has been studied for its well-established anti-rheumatoid arthritis properties. In this study, we attempted to use the anti-RA material AESIS-1 as a therapeutic wound-healing agent based on disease-modifying antirheumatic drugs (DMARDs), which can help restore prompt wound healing. The efficacy of AESIS-1 in wound healing was assessed using a full-thickness excision model in diabetic mice; this is a well-established model for studying chronic wound repair. Initial observations revealed that mice treated with AESIS-1 exhibited significantly advanced wound repair compared with the control group. In vitro studies revealed that AESIS-1 increased the migration activity of human dermal fibroblasts (HDFs) without affecting proliferative activity. Moreover, increased HDF cell migration is mediated by upregulating chemokine receptor expression, such as that of CXC chemokine receptor 2 (CXCR2). The upregulation of CXCR2 through AESIS-1 treatment enhanced the chemotactic reactivity to CXCR2 ligands, including CXC motif ligand 8 (CXCL8). AESIS-1 directly activates the ERK and p38 mitogen-activated protein kinase (MAPK) signaling cascades, which regulate the migration and expression of CXCR2 in fibroblasts. Our results suggest that the AESIS-1 peptide is a strong wound-healing substance that increases the movement of fibroblasts and the expression of CXCR2 by turning on the ERK and p38 MAPK signaling cascades.

Interleukin-8 is superior to CRP for the prediction of severe complications in a prospective cohort of patients undergoing major liver resection

INTRODUCTION

Early detection of severe complications may reduce morbidity and mortality in patients undergoing hepatic resection. Therefore, we prospectively evaluated a panel of inflammatory blood markers for their value in predicting postoperative complications in patients undergoing liver surgery.

METHODS

A total of 139 patients undergoing liver resections (45 wedge resections, 49 minor resections, and 45 major resections) were prospectively enrolled between August 2017 and December 2018. Leukocytes, CRP, neutrophil-lymphocyte ratio (NLR), thrombocyte-lymphocyte ratio (TLR), bilirubin, INR, and interleukin-6 and -8 (IL-6 and IL-8) were measured in blood drawn preoperatively and on postoperative days 1, 4, and 7. IL-6 and IL-8 were measured using standardized immunoassays approved for in vitro diagnostic use in Germany. ROC curve analysis was used to determine predictive values for the occurrence of severe postoperative complications (CDC ≥ 3).

RESULTS

For wedge and minor resections, leukocyte counts at day 7 (AUC 0.80 and 0.82, respectively), IL-6 at day 7 (AUC 0.74 and 0.73, respectively), and CRP change (∆CRP) at day 7 (AUC 0.72 and 0.71, respectively) were significant predictors of severe postoperative complications. IL-8 failed in patients undergoing wedge resections, but was a significant predictor of severe complications after minor resections on day 7 (AUC 0.79), had the best predictive value in all patients on days 1, 4, and 7 (AUC 0.72, 0.72, and 0.80, respectively), and was the only marker with a significant predictive value in patients undergoing major liver resections (AUC on day 1: 0.70, day 4: 0.86, and day 7: 0.92). No other marker, especially not CRP, was predictive of severe complications after major liver surgery.

CONCLUSION

IL-8 is superior to CRP in predicting severe complications in patients undergoing major hepatic resection and should be evaluated as a biomarker for patients undergoing major liver surgery. This is the first paper demonstrating a feasible implementation of IL-8 analysis in a clinical setting.

Inflammation biomarkers IL‑6 and IL‑10 may improve the diagnostic and prognostic accuracy of currently authorized traumatic brain injury tools

Traumatic brain injury (TBI) is currently one of the leading causes of mortality and disability worldwide. At present, no reliable inflammatory or specific molecular neurobiomarker exists in any of the standard models proposed for TBI classification or prognostication. Therefore, the present study was designed to assess the value of a group of inflammatory mediators for evaluating acute TBI, in combination with clinical, laboratory and radiological indices and prognostic clinical scales. In the present single-centre, prospective observational study, 109 adult patients with TBI, 20 adult healthy controls and a pilot group of 17 paediatric patients with TBI from a Neurosurgical Department and two intensive care units of University General Hospital of Heraklion, Greece were recruited. Blood measurements using the ELISA method, of cytokines IL-6, IL-8 and IL-10, ubiquitin C-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein, were performed. Compared with those in healthy control individuals, elevated IL-6 and IL-10 but reduced levels of IL-8 were found on day 1 in adult patients with TBI. In terms of TBI severity classifications, higher levels of IL-6 (P=0.001) and IL-10 (P=0.009) on day 1 in the adult group were found to be associated with more severe TBI according to widely used clinical and functional scales. Moreover, elevated IL-6 and IL-10 in adults were found to be associated with more serious brain imaging findings (rs<0.442; P<0.007). Subsequent multivariate logistic regression analysis in adults revealed that early-measured (day 1) IL-6 [odds ratio (OR)=0.987; P=0.025] and UCH-L1 (OR=0.993; P=0.032) are significant independent predictors of an unfavourable outcome. In conclusion, results from the present study suggest that inflammatory molecular biomarkers may prove to be valuable diagnostic and prognostic tools for TBI.

Are There Differences in Inflammatory and Fibrotic Pathways between IPAF, CTD-ILDs, and IIPs? A Single-Center Pilot Study

In this pilot study, we aim to determine differences in pathogenetic pathways between interstitial pneumonia with autoimmune features (IPAF), connective-tissue-disease-associated interstitial lung diseases (CTD-ILDs), and idiopathic interstitial pneumonias (IIPs). Forty participants were recruited: 9 with IPAF, 15 with CTD-ILDs, and 16 with IIPs. Concentration of transforming growth factor beta (TGF-β1), surfactant proteins A and D (SP-A, SP-D), interleukin 8 (IL-8), and chemokine 1 (CXCL1) were assessed with ELISA assay in bronchoalveolar lavage (BAL) fluid. We revealed that IL-8 and TGF-β1 concentrations were significantly lower in the IPAF group than in the CTD-ILD group (p = 0.008 and p = 0.019, respectively), but similar to the concentrations in the IIP group. There were significant correlations of IL-8 (rs = 0.46; p = 0.003) and CXCL1 (rs = 0.52; p = 0.001) and BAL total cell count (TCC). A multivariate regression model revealed that IL-8 (β = 0.32; p = 0.037) and CXCL1 (β = 0.45; p = 0.004) are significant predictors of BAL TCC. We revealed that IL-8 and TGF-β1 BAL concentrations vary in patients with different ILDs and found that IL-8 is a predictor of BAL TCC in IPAF. However, this needs to be confirmed in a multicenter cooperative study (ClinicalTrials.gov Identifier: NCT03870828).

The role of CXCL8 in chronic nonhealing diabetic foot ulcers and phenotypic changes in fibroblasts: a molecular perspective

INTRODUCTION

A persistent inflammation is perpetuated by infiltrating immune cells and cytokines secreted from these immune cells. Additionally, apoptotic keratinocytes and adipocytes in diabetes causes diabetic foot ulcer (DFU) to arrest in an inflammatory phase without progressing to the resolution phase. This leads to a nonhealing DFU and, despite advanced treatments consisting of wound debridement, off-loading the ulcer of necrotic tissue, wound dressings to keep it moist and control exudate, medication, and preventing infection, DFUs remain a clinical problem. Nonhealing DFUs pose not only an economic burden but also increased morbidity and mortality in the form of psychological stress with and increased chance of amputation, and even death. Thus, investigating the complicated underlying molecular mechanism responsible for nonhealing patterns and designing better therapeutics is warranted. This review article focuses on the role of IL-8-mediated persistent inflammation and phenotypic change of fibroblasts due to this inflammatory cascade. We have discussed various sources of interleukin (IL)-8 secretion and the possible association of IL8-fibroblast plasticity as a cause of nonhealing DFUs.

MATERIAL AND METHODS

A literature search on PubMed, Google Scholar, and PMC was done including the terms diabetic foot ulcer, diabetes, diabetic ulcer, chronic inflammation, interleukin 8, diabetic wound, and nonhealing diabetic foot ulcers. The articles in the English language and published in last 10 years were selected. From the pool of these, the articles describing the relationship between IL-8 and nonhealing diabetic foot ulcer and diabetic ulcer were used sorted out and used for this review article following PRISMA guidelines.

CONCLUSION

Increased infiltration of inflammatory immune cells, secretion of pro-inflammatory cytokines, altered keratinocyte-fibroblast function, and phenotypic changes of fibroblasts in DFUs seem to be critical to the nonhealing of DFUs. Thus, inhibiting IL-8 secretion and downstream signaling seems to be a goal of potential therapeutics.

Comparison of two lipid emulsions on interleukin-1β, interleukin-8 and fatty acid composition in infants post gastrointestinal surgery: a randomized trial

Background: Nutritional support plays an essential role for recovery in infants who undergo gastrointestinal surgery. The current standard type of intravenous lipid emulsion (IVLE) used as parenteral nutrition is the mixture of medium-chain triglyceride (MCT) and long chain triglyceride (LCT) rich in ω-6. Studies showed that ω-6 is associated with higher level of proinflammatory cytokines, leading to increased mortality rate, morbidity rate, and postoperative recovery time. The latest generation of emulsion is a mixture of MCT, LCT, olive oil (OO), and fish oil (FO) which may optimize the ω6/ω3 ratio. This study aimed to compare the effect of MCT/LCT/OO/FO IVLE to standard IVLE on IL-1β, IL-8 and serum fatty acids in infants who had undergone gastrointestinal surgery. Methods: A single-blind, randomised controlled, pretest-posttest design study was done in twelve subjects that were classified into two groups. Group 1 received standard IVLE, group 2 received MCT/LCT/OO/FO IVLE. The type of standard and MCT/LCT/OO/FO IVLE used in this study were Lipofundin 20% and SMOFlipid 20%, respectively, both administered for three consecutive days in 1-4 gram/kilogram/day. IL-1β and IL-8 were examined using ELISA while fatty acids was analyzed using gas chromatography tandem mass spectrometry (GC-MS). Statistical analyses were performed using SPSS for Mac 23. Results: No statistical difference was found in age, gender, birth weight and diagnosis between both groups. Leukocyte was significantly lower in MCT/LCT/OO/FO group 3 days after surgery (p=0.025). CRP was lower in MCT/LCT/OO/FO group 3 days after surgery (p=0.01) and in changes within 3 days (p=0.016). There were no differences in IL-1β, IL-8 and ω-3 but ω-6 was higher in standard IVFE group on third day after surgery (p=0,048) Conclusion: MCT/LCT/OO/FO IVLE can significantly lower leukocyte, CRP and ω-6 levels and is comparable with standard IVLE on IL-1β, IL-8 and ω-3 levels in infants who had undergone gastrointestinal surgery.

Comprehensive Proteomic Profiling of Pressure Ulcers in Patients with Spinal Cord Injury Identifies a Specific Protein Pattern of Pathology

Objective: Severe pressure ulcers (PUs) do not respond to conservative wound therapy and need surgical repair. To better understand the pathogenesis and to advance on new therapeutic options, we focused on the proteomic analysis of PU, which offers substantial opportunities to identify significant changes in protein abundance during the course of PU formation in an unbiased manner. Approach: To better define the protein pattern of this pathology, we performed a proteomic approach in which we compare severe PU tissue from spinal cord injury (SCI) patients with control tissue from the same patients. Results: We found 76 proteins with difference in abundance. Of these, 10 proteins were verified as proteins that define the pathology: antithrombin-III, alpha-1-antitrypsin, kininogen-1, alpha-2-macroglobulin, fibronectin, apolipoprotein A-I, collagen alpha-1 (XII) chain, haptoglobin, apolipoprotein B-100, and complement factor B. Innovation: This is the first study to analyze differential abundance protein of PU tissue from SCI patients using high-throughput protein identification and quantification by tandem mass tags followed by liquid chromatography tandem mass spectrometry. Conclusion: Differential abundance proteins are mainly involved in tissue regeneration. These proteins might be considered as future therapeutic options to enhance the physiological response and permit cellular repair of damaged tissue.

Bronchial epithelium repair by Esculentin-1a-derived antimicrobial peptides: involvement of metalloproteinase-9 and interleukin-8, and evaluation of peptides' immunogenicity

The airway epithelium is seriously damaged upon pulmonary Pseudomonas aeruginosa infection, especially in cystic fibrosis (CF) sufferers. Therefore, the discovery of novel anti-infective agents accelerating healing of infected injured tissues is crucial. The antipseudomonal peptides esculentin-1a(1–21)NH₂ and its diastereomer Esc(1–21)-1c (Esc peptides) hold promise in this respect. In fact, they stimulate airway epithelial wound repair, but no mechanistic insights are available. Here we demonstrated that this process occurs through promotion of cell migration by an indirect activation of epidermal growth factor receptor mediated by metalloproteinases. Furthermore, we showed an increased expression of metalloproteinase 9, at both gene and protein levels, in peptide-treated bronchial epithelial cells with a functional or mutated form of CF transmembrane conductance regulator. In addition, the two peptides counteracted the inhibitory effect of Pseudomonas lipopolysaccharide (mimicking an infection condition) on the wound healing activity of the airway epithelium, and they enhanced the production of interleukin-8 from both types of cells. Finally, no immunogenicity was discovered for Esc peptides, suggesting their potential safety for clinical usage. Besides representing a step forward in understanding the molecular mechanism underlying the peptide-induced wound healing activity, these studies have contributed to highlight Esc peptides as valuable therapeutics with multiple functions.

Gemcitabine: Selective cytotoxicity, induction of inflammation and effects on urothelial function

Intravesical gemcitabine has recently been introduced for the treatment of superficial bladder cancer and has a favourable efficacy and toxicity profile in comparison to mitomycin c (MMC), the most commonly used chemotherapeutic agent. The aim of this study was to assess the cytotoxic potency of gemcitabine in comparison to MMC in urothelial cell lines derived from non-malignant (UROtsa) and malignant (RT4 and T24) tissues to assess selectivity. Cells were treated with gemcitabine or mitomycin C at concentrations up to the clinical doses for 1 or 2h respectively (clinical duration). Treatment combined with hyperthermia was also examined. Cell viability, ROS formation, urothelial function (ATP, acetylcholine and PGE2 release) and secretion of inflammatory cytokines were assessed. Gemcitabine displayed a high cytotoxic selectivity for the two malignant cell lines (RT4, T24) compared to the non-malignant urothelial cells (UROtsa, proliferative and non-proliferative). In contrast, the cytotoxic effects of MMC were non-selective with equivalent potency in each of the cell lines. The cytotoxic effect of gemcitabine in the malignant cell lines was associated with an elevation in free radical formation and was significantly decreased in the presence of an equilibrative nucleoside transporter inhibitor. Transient changes in urothelial ATP and PGE₂ release were observed, with significant increase in release of interleukin-6, interleukin-8 and interleukin-1β from urothelial cells treated with gemcitabine. The selectivity of gemcitabine for malignant urothelial cells may account for the less frequent adverse urological effects with comparison to other commonly used chemotherapeutic agents.

Interleukins 6 and 8 and abdominal fat depots are distinct correlates of lipid moieties in healthy pre- and postmenopausal women

Available data associate lipids concentrations in men with body mass index, anabolic steroids, age, and certain cytokines. Data were less clear in women, especially across the full adult lifespan, and when segmented by premenopausal and postmenopausal status.

SUBJECTS

120 healthy women (60 premenopausal and 60 postmenopausal) in Olmsted County, MN, USA, a stable well studied clinical population. Dependent variables: measurements of 10 h fasting high-density lipoprotein cholesterol, total cholesterol, low-density lipoprotein cholesterol, and triglycerides.

INDEPENDENT VARIABLES

testosterone, estrone, estradiol, 5-alpha-dihydrotestosterone, and sex-hormone binding globulin (by mass spectrometry); insulin, glucose, and albumin; abdominal visceral, subcutaneous, and total abdominal fat [abdominal visceral fat, subcutaneous fat, total abdominal fat by computerized tomography scan]; and a panel of cytokines (by enzyme-linked immunosorbent assay). Multivariate forward-selection linear-regression analysis was applied constrained to P < 0.01. Lifetime data: High-density lipoprotein cholesterol was correlated jointly with age (P < 0.0001, positively), abdominal visceral fat (P < 0.0001, negatively), and interleukin-6 (0.0063, negatively), together explaining 28.1 % of its variance (P = 2.3 × 10^-8). Total cholesterol was associated positively with multivariate age only (P = 6.9 × 10^-4, 9.3 % of variance). Triglycerides correlated weakly with sex-hormone binding globulin (P = 0.0115), and strongly with abdominal visceral fat (P < 0.0001), and interleukin-6 (P = 0.0016) all positively (P = 1.6 × 10^-12, 38.9 % of variance). Non high-density lipoprotein cholesterol and low-density lipoprotein cholesterol correlated positively with both total abdominal fat and interleukin-8 (P = 2.0 × 10^-5, 16.9 % of variance; and P = 0.0031, 9.4 % of variance, respectively). Premenopausal vs. postmenopausal comparisons identified specific relationships that were stronger in premenopausal than postmenopausal individuals, and vice versa. Age was a stronger correlate of low-density lipoprotein cholesterol; interleukin-6 of triglycerides and high-density lipoprotein; and both sex-hormone binding globulin and total abdominal fat of non high-density lipoprotein cholesterol in premenopausal than postmenopausal women. Conversely, sex-hormone binding globulin, abdominal visceral fat, interleukin-8, adiponectin were stronger correlates of triglycerides; abdominal visceral fat, and testosterone of high-density lipoprotein cholesterol; and age of both non high-density lipoprotein and low-density lipoprotein in postmenopausal than premenopausal women. Our data delineate correlations of total abdominal fat and interleukin-8 (both positively) with non high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in healthy women across the full age range of 21-79 years along with even more specific associations in premenopausal and postmenopausal individuals. Whether some of these outcomes reflect causal relationships would require longitudinal and interventional or genetic studies.

Serum concentrations of HGF and IL-8 in patients with active Graves' orbitopathy before and after methylprednisolone therapy

INTRODUCTION

Graves' disease is the most common cause of hyperthyroidism, and orbitopathy is the most frequent extrathyroidal manifestation of Graves' disease. The aims of this study were as follows: (1) to evaluate the serum concentration of HGF and IL-8 in the blood of newly diagnosed Graves' disease patients with the first episode of active GO and healthy controls; (2) to estimate the influence of the thyroid function (euthyreosis vs. hyperthyreosis) on HGF and IL-8 blood levels in patients with active GO; (3) to evaluate the influence of intravenous (i.v.) methylprednisolone (MP) pulse therapy and additional oral MP treatment on HGF and IL-8 blood levels in patients with active GO.

PATIENTS AND METHODS

Thirty-nine Graves' disease patients with the first episode of clinically active GO (Group A) were enrolled in the study. To estimate the influence of the thyroid function on serum concentrations of the studied proangiogenic factors, Group A was divided into Group A I (n = 18) in euthyroid and Group A II (n = 21) in hyperthyroid stage of Graves' disease in moderate-to-severe stage of GO. The control group consisted of 20 healthy volunteers age- and sex-matched to the GO group. Concentrations of the studied proangiogenic factors in serum samples were measured by an enzyme-linked immunosorbent assay before (Group A) and after (Group A1) intensive pulse i.v.MP treatment and 1 month after the end of additional oral MP treatment (Group A2).

RESULTS

We found a significant increase in serum concentrations of studied factors in the GO group before immunosuppressive therapy when compared with the control group and decrease after i.v.MP treatment. One month after the end of additional oral MP treatment (Group A2), serum concentrations of HGF and IL-8 still decreased and no significant difference was observed in HGF and IL-8 concentrations when compared with the control group. We did not find the difference in serum concentration of the studied proangiogenic factors between patients in euthyroid and hyperthyroid stage of Graves' disease before MP therapy.

CONCLUSIONS

Serum HGF and IL-8 concentrations are elevated in Graves' disease patients with active Graves' orbitopathy as compared to the healthy control group. Successful management of active Graves' orbitopathy with glucocorticoids is associated with a decrease in HGF and IL-8 serum concentrations.

The effect of LDL particles on the behaviour of epithelial noncancer and cancer cell lines after in vitro induced injury

Cell spreading capability and cell proliferation are the major processes in wound healing of injured epithelia as well as in tumour progression. The effect of low-density lipoprotein (LDL) particles as a major extracellular source of cholesterol was evaluated in the re-epithelisation assay of in vitro induced injury. We selected two noncancer cell lines with different dependence on LDL concentrations, the kidney epithelial cells (MDCK) with higher dependence and keratinocytes (HaCaT) with lower dependence on LDL, and three cancer cell lines originating from epithelial cells: A549 (alveolar), CaCo-2 (intestinal) and RT4 (urothelial). All cells were incubated in a control medium, in an LDL-enriched medium or in an LDL-deficient medium. The LDL-enriched medium stimulated cell spreading of MDCK cells which, together with increased proliferation of these cells, resulted in an enhanced re-epithelisation of in vitro induced injury. LDL deficiency caused lower cell spreading which resulted in a decreased re-epithelisation despite the higher proliferation of MDCK cells in this medium. The re-epithelisation of keratinocytes (HaCaT) was not affected by altered LDL concentrations. In cancer cell lines A549, CaCo-2 and RT4, wide heterogeneity regarding cell proliferation and spreading capability was observed after treatment with different LDL concentrations. LDL had no influence on actin filament and tight junction distribution in any of the tested cell lines. The cholesterol content of all cell types, except for CaCo-2 cells, proved to be independent of the LDL level. Further research of the beneficial effects of LDL is needed to prove LDL as a safe enhancer of epithelial wound healing.

Gene expression profile of normal and cancer-associated fibroblasts according to intratumoral inflammatory cells phenotype from breast cancer tissue

The biological heterogeneity of breast cancer leads to the need for finding new approaches to understand the mechanisms implicated in breast cancer progression. The tumor stroma appears as a key in the progression of solid tumors towards a malignant phenotype. Cancer associated fibroblasts (CAFs) may orchestrate a functional "corrupted" stroma which in turn helps metastatic spread. In this study, we investigated by real-time PCR, the expression of 19 factors by normal breast-associated fibroblasts (NAFs) and CAFs, which were implicated in several actions promoting tumor growth, such as extracellular matrix remodeling, inflammation and invasion. Also, we explored the influence of inflammatory cells phenotypes (MMP11 status) and breast cancer cell lines (MCF-7 and MDA-MB-231) on the molecular profile of CAFs. If we consider that one of the major sources of CAFs are resident NAFs, the transition of NAFs into CAFs is associated with molecular changes involving the overexpression of some molecular factors of biological importance in tumor progression. In addition, the characterization of the tumor stroma regarding to the MMP11 status by MICs reflects a type of fibroblasts which contribute even more to tumor progression. Moreover, different patterns in the induction of the expression of factors by CAFs were observed, depending on the tumor cell line which they were co-cultured with. Furthermore, CAFs influence TGFβ expression in both cancer cell lines. Therefore, this study can help to a better characterization of tumor stroma in order to improve the prognostic evaluation, as well as to define the different populations of CAFs as potential therapeutic targets in breast cancer. © 2015 Wiley Periodicals, Inc.

Rsu1 contributes to cell adhesion and spreading in MCF10A cells via effects on P38 map kinase signaling

The ILK, PINCH, Parvin (IPP) complex regulates adhesion and migration via binding of ILK to β1 integrin and α−parvin thus linking focal adhesions to actin cytoskeleton. ILK also binds the adaptor protein PINCH which connects signaling proteins including Rsu1 to the complex. A recent study of Rsu1 and PINCH1 in non-transformed MCF10A human mammary epithelial cells revealed that the siRNA-mediated depletion of either Rsu1 or PINCH1 decreased the number of focal adhesions (FAs) and altered the distribution and localization of FA proteins. This correlated with reduced adhesion, failure to spread or migrate in response to EGF and a loss of actin stress fibers and caveolae. The depletion of Rsu1 caused significant reduction in PINCH1 implying that Rsu1 may function in part by regulating levels of PINCH1. However, Rsu1, but not PINCH1, was required for EGF-induced activation of p38 Map kinase and ATF2 phosphorylation, suggesting a Rsu1 function independent from the IPP complex. Reconstitution of Rsu1-depleted cells with a Rsu1 mutant (N92D) that does not bind to PINCH1 failed to restore FAs or migration but did promote IPP-independent spreading and constitutive as well as EGF-induced p38 activation. In this commentary we discuss p38 activity in adhesion and how Rsu1 expression may be linked to Map kinase kinase (MKK) activation and detachment-induced stress kinase signaling.

The Impact of Lipoproteins on Wound Healing: Topical HDL Therapy Corrects Delayed Wound Healing in Apolipoprotein E Deficient Mice

Chronic non-healing wounds lead to considerable morbidity and mortality. Pleiotropic effects of high density lipoproteins (HDL) may beneficially affect wound healing. The objectives of this murine study were: (1) to investigate the hypothesis that hypercholesterolemia induces impaired wound healing and (2) to study the effect of topical HDL administration in a model of delayed wound healing. A circular full thickness wound was created on the back of each mouse. A silicone splint was used to counteract wound contraction. Coverage of the wound by granulation tissue and by epithelium was quantified every 2 days. Re-epithelialization from day 0 till day 10 was unexpectedly increased by 21.3% (p < 0.05) in C57BL/6 low density lipoprotein (LDLr) deficient mice with severe hypercholesterolemia (489 ± 14 mg/dL) compared to C57BL/6 mice and this effect was entirely abrogated following cholesterol lowering adenoviral LDLr gene transfer. In contrast, re-epithelialization in hypercholesterolemic (434 ± 16 mg/dL) C57BL/6 apolipoprotein (apo) E^−/− mice was 22.6% (p < 0.0001) lower than in C57BL/6 mice. Topical HDL gel administered every 2 days increased re-epithelialization by 25.7% (p < 0.01) in apo E^−/− mice. In conclusion, topical HDL application is an innovative therapeutic strategy that corrects impaired wound healing in apo E^−/− mice.

A role for CD81 and hepatitis C virus in hepatoma mobility

Tetraspanins are a family of small proteins that interact with themselves, host transmembrane and cytosolic proteins to form tetraspanin enriched microdomains (TEMs) that regulate important cellular functions. Several tetraspanin family members are linked to tumorigenesis. Hepatocellular carcinoma (HCC) is an increasing global health burden, in part due to the increasing prevalence of hepatitis C virus (HCV) associated HCC. The tetraspanin CD81 is an essential receptor for HCV, however, its role in hepatoma biology is uncertain. We demonstrate that antibody engagement of CD81 promotes hepatoma spread, which is limited by HCV infection, in an actin-dependent manner and identify an essential role for the C-terminal interaction with Ezrin-Radixin-Moesin (ERM) proteins in this process. We show enhanced hepatoma migration and invasion following expression of CD81 and a reduction in invasive potential upon CD81 silencing. In addition, we reveal poorly differentiated HCC express significantly higher levels of CD81 compared to adjacent non-tumor tissue. In summary, these data support a role for CD81 in regulating hepatoma mobility and propose CD81 as a tumour promoter.

Rsu1 contributes to regulation of cell adhesion and spreading by PINCH1-dependent and - independent mechanisms

Cell adhesion and migration are complex processes that require integrin activation, the formation and dissolution of focal adhesion (FAs), and linkage of actin cytoskeleton to the FAs. The IPP (ILK, PINCH, Parvin) complex regulates FA formation via binding of the adaptor protein ILK to β1 integrin, PINCH and parvin. The signaling protein Rsu1 is linked to the complex via binding PINCH1. The role of Rsu1 and PINCH1 in adhesion and migration was examined in non-transformed mammary epithelial cells. Confocal microscopy revealed that the depletion of either Rsu1 or PINCH1 by siRNA in MCF10A cells decreased the number of focal adhesions and altered the distribution and localization of β1 integrin, vinculin, talin and paxillin without affecting the levels of FA protein expression. This correlated with reduced adhesion, failure to spread or migrate in response to EGF and a loss of actin stress fibers and caveolae. In addition, constitutive phosphorylation of actin regulatory proteins occurred in the absence of PINCH1. The depletion of Rsu1 caused significant reduction in PINCH1 implying that Rsu1 may function by regulating levels of PINCH1. However, while both Rsu1- or PINCH1-depleted cells retained the ability to activate adhesion signaling in response to EGF stimulation, only Rsu1 was required for EGF-induced p38 Map Kinase phosphorylation and ATF2 activation, suggesting an Rsu1 function independent from the IPP complex. Reconstitution of Rsu1-depleted cells with an Rsu1 mutant that does not bind to PINCH1 failed to restore FAs or migration but did promote spreading and constitutive p38 activation. These data show that Rsu1-PINCH1 association with ILK and the IPP complex is required for regulation of adhesion and migration but that Rsu1 has a critical role in linking integrin-induced adhesion to activation of p38 Map kinase signaling and cell spreading. Moreover, it suggests that Rsu1 may regulate p38 signaling from the IPP complex affecting other functions including survival.

Co-stimulation of PAFR and CD36 is required for oxLDL-induced human macrophages activation

The oxidative process of LDL particles generates molecules which are structurally similar to platelet-activating factor (PAF), and some effects of oxidized LDL (oxLDL) have been shown to be dependent on PAF receptor (PAFR) activation. In a previous study, we showed that PAFR is required for upregulation of CD36 and oxLDL uptake. In the present study we analyzed the molecular mechanisms activated by oxLDL in human macrophages and the contribution of PAFR to this response. Human adherent monocytes/macrophages were stimulated with oxLDL. Uptake of oxLDL and CD36 expression were determined by flow cytometry; MAP kinases and Akt phosphorylation by Western blot; IL-8 and MCP-1 concentration by ELISA and mRNA expression by real-time PCR. To investigate the participation of the PI3K/Akt pathway, Gαi-coupled protein or PAFR, macrophages were treated with LY294002, pertussis toxin or with the PAFR antagonists WEB2170 and CV3988, respectively before addition of oxLDL. It was found that the addition of oxLDL to human monocytes/macrophages activates the PI3K/Akt pathway which in turn activates the MAPK (p38 and JNK). Phosphorylation of Akt requires the engagement of PAFR and a Gαi-coupled protein. The upregulation of CD36 protein and the uptake of oxLDL as well as the IL-8 production are dependent on PI3K/Akt pathway activation. The increased CD36 protein expression is dependent on PAFR and Gαi-coupled protein. Transfection studies using HEK 293t cells showed that oxLDL uptake occurs with either PAFR or CD36, but IL-8 production requires the co-transfection of both PAFR and CD36. These findings show that PAFR has a pivotal role in macrophages response to oxLDL and suggest that pharmacological intervention at the level of PAFR activation might be beneficial in atherosclerosis.

Recent advances in underlying pathologies provide insight into interleukin-8 expression-mediated inflammation and angiogenesis

Interleukin-8 has long been recognized to have anti-inflammatory activity, which has been established in various models of infection, inflammation, and cancer. Several cell types express the receptor for the cytokine IL-8 and upon its recognition produce molecules that are active both locally and systemically. Many different types of cells, in particular monocytes, neutrophils, epithelial, fibroblast, endothelial, mesothelial, and tumor cells, secrete IL-8. Increased expression of IL-8 and/or its receptors has been characterized in many chronic inflammatory conditions, including psoriasis, ARDS, COPD, and RA as well as many cancers, and its upregulation often correlates with disease activity. IL-8 constitutes the CXC class of chemokines, a potent chemoattractant and activator of neutrophils and other immune cells. It is a proangiogenic cytokine that is overexpressed in many human cancers. Therefore, inhibiting the effects of IL-8 signaling may be a significant therapeutic intervention.

Interleukin-8 is associated with proliferation, migration, angiogenesis and chemosensitivity in vitro and in vivo in colon cancer cell line models

Interleukin-8 (IL-8), a chemokine with a defining CXC amino acid motif, is known to possess tumorigenic and proangiogenic properties. Overexpression of IL-8 has been detected in many human tumors, including colorectal cancer (CRC), and is associated with poor prognosis. The goal of our study was to determine the role of IL-8 overexpression in CRC cells in vitro and in vivo. We stably transfected the IL-8 cDNA into two human colon cancer cell lines, HCT116 and Caco2, and selected IL-8-secreting transfectants. Real-time RT-PCR confirmed that IL-8 mRNA was overexpressed in IL-8 transfectants with 45- to 85-fold higher than parental cells. The IL-8-transfected clones secreted 19- to 28-fold more IL-8 protein than control and parental cells as detected by ELISA. The IL-8 transfectants demonstrated increased cellular proliferation, cell migration and invasion based on functional assays. Growth inhibition studies showed that IL-8 overexpression lead to a significant resistance to oxaliplatin (p < 0.0001). Inhibition of IL-8 overexpression with small interfering RNA reversed the observed increases in tumorigenic functions and oxaliplatin resistance, suggesting that IL-8 not only provides a proliferative advantage but also promotes the metastatic potential of colon cancer cells. Using a tumor xenograft model, IL-8-expressing cells formed significantly larger tumors than the control cells with increased microvessel density. Together, these findings indicate that overexpression of IL-8 promotes tumor growth, metastasis, chemoresistance and angiogenesis, implying IL-8 to be an important therapeutic target in CRC.

Interleukin-8 is associated with proliferation, migration, angiogenesis and chemosensitivity in vitro and in vivo in colon cancer cell line models

Interleukin-8 (IL-8), a chemokine with a defining CXC amino acid motif, is known to possess tumorigenic and proangiogenic properties. Overexpression of IL-8 has been detected in many human tumors, including colorectal cancer (CRC), and is associated with poor prognosis. The goal of our study was to determine the role of IL-8 overexpression in CRC cells in vitro and in vivo. We stably transfected the IL-8 cDNA into two human colon cancer cell lines, HCT116 and Caco2, and selected IL-8-secreting transfectants. Real-time RT-PCR confirmed that IL-8 mRNA was overexpressed in IL-8 transfectants with 45- to 85-fold higher than parental cells. The IL-8-transfected clones secreted 19- to 28-fold more IL-8 protein than control and parental cells as detected by ELISA. The IL-8 transfectants demonstrated increased cellular proliferation, cell migration and invasion based on functional assays. Growth inhibition studies showed that IL-8 overexpression lead to a significant resistance to oxaliplatin (p < 0.0001). Inhibition of IL-8 overexpression with small interfering RNA reversed the observed increases in tumorigenic functions and oxaliplatin resistance, suggesting that IL-8 not only provides a proliferative advantage but also promotes the metastatic potential of colon cancer cells. Using a tumor xenograft model, IL-8-expressing cells formed significantly larger tumors than the control cells with increased microvessel density. Together, these findings indicate that overexpression of IL-8 promotes tumor growth, metastasis, chemoresistance and angiogenesis, implying IL-8 to be an important therapeutic target in CRC.

Signal transduction pathways involved in brain death-induced renal injury

Kidneys derived from brain death organ donors show an inferior survival when compared to kidneys derived from living donors. Brain death is known to induce organ injury by evoking an inflammatory response in the donor. Neuronal injury triggers an inflammatory response in the brain, leading to endothelial dysfunction and the release of cytokines in the circulation. Serum levels of interleukin-6, -8, -10, and monocyte chemoattractant protein-1 (MCP-1) are increased after brain death. Binding with cytokine-receptors in kidneys stimulates activation of nuclear factor-kappa B (NF-kappaB), selectins, adhesion molecules and production of chemokines leading to cellular influx. Mitogen-activated protein kinases (MAP-kinases) mediate inflammatory responses and together with NF-kappaB they seem to play an important role in brain death induced renal injury. Altering the activation state of MAP-kinases could be a promising drug target for early intervention to reduce cerebral injury related donor kidney damage and improve outcome after transplantation.

Tribbles-2 is a novel regulator of inflammatory activation of monocytes

Inflammatory activation of monocytes is an essential part of both innate immune responses and the pathogenesis of conditions such as atherosclerosis. However, the mechanisms which modulate the response of monocytes to inflammatory stimuli are still poorly understood. Here, we report that tribbles-2 (trb-2) is a novel regulator of inflammatory activation of monocytes. Down-regulation of trb-2 levels potentiates LPS-induced IL-8 production via enhanced activation of the extracellular signal-regulated kinase and jun kinase mitogen-activated protein kinase (MAPK) pathways. In keeping with this, the endogenous level of trb-2 expression in human primary monocytes is inversely correlated to the cell’s ability to produce IL-8. We show that trb-2 is a binding partner and a negative regulator of selected MAPKs. The potential in vivo relevance of these findings is highlighted by the observation that modified low-density lipoprotein profoundly down-regulates trb-2 expression, which may, in turn, significantly contribute to the inflammatory processes in the development of vascular disease. Taken together, our results define trb-2 as a potent novel regulator of monocyte biology, controlling the activation of these cells.

Systemic host immuno-inflammatory response to dental extractions and periodontitis

OBJECTIVES

Little is known about the host immuno-inflammatory response to dental extractions. The purpose of this pilot clinical study was to explore the effect of both periodontitis and dental extractions on the host systemic immuno-inflammatory response.

STUDY DESIGN

We recruited and collected baseline blood samples on 41 essentially healthy patients. A subset of 22 subjects underwent single (n = 11) or multiple (n = 11) tooth extractions with additional blood samples taken at 1 hour following single tooth extraction and at 8 and 24 hours following multiple tooth extractions. Samples were used for determination of an array of 12 cytokines known to play key roles in innate and adaptive immunity.

RESULTS

There was no significant difference in cytokine levels between the pre- and post-tooth extraction samples for either extraction group for the time points measured. Nor was there a positive relationship between the level of any of the cytokines and periodontal disease status as measured by mean probing depths and other periodontal disease parameters.

CONCLUSION

Our pilot data suggest that the body is well adjusted to deal with the inflammation and bacteremia associated with dental extractions and periodontal disease.

Activated stress response pathways within multicellular aggregates utilize an autocrine component

Multicellular aggregates (spheroids) of primary human foreskin fibroblasts (HFF-2) and a glioblastoma cell line (T98G) entered and exited from long term (2 weeks) metabolic arrest utilizing an autocrine response. Cytokine production (specifically IFN-gamma) activated a Gadd45alpha/p38 pathway that led to increased AP-1 (c-jun and ATF3) transcription factor levels, augmenting cytokine production in an autocrine fashion. Whereas HFF-2 aggregates were capable of surviving long term arrest and recovery during NF-kappaB inhibition independent of JNK activation, T98G aggregates were not. Such endogenous processes are not easily observed with adherent monolayer cell culturing systems, strongly suggesting that more emphasis needs to be placed on determining the operational signal transduction cascades within multicellular aggregates. Extracellular inputs such as spheroid formation, arrest, and regrowth as monolayers invoke intracellular signaling responses converging at the AP-1 transcription factor level. Variations in responses are both cell type and transformation state dependent and require an autocrine cytokine component. The data are discussed in relation to the wounding response and avascular tumor growth mechanisms.

Low-Density Lipoprotein Modified by Macrophage-Derived Lysosomal Hydrolases Induces Expression and Secretion of IL-8 Via p38 MAPK and NF-κB by Human Monocyte-Derived Macrophages

OBJECTIVE

Modified lipoproteins induce inflammatory reactions in the atherosclerotic arterial wall. We have previously found that macrophages in atherosclerotic lesions secrete lysosomal hydrolases that can modify low-density-lipoprotein (LDL) in vitro to generate "hydrolase-modified LDL" (H-LDL). Here, we studied whether H-LDL exerts inflammatory effects on cultured human macrophages.

METHODS AND RESULTS

Using cytokine cDNA arrays, we found that H-LDL induced expression of IL-8, but not of the anti-inflammatory cytokines IL-10 and transforming growth factor (TGF)-beta, in human monocyte-derived macrophages. H-LDL induced rapid phosphorylation of the p38 mitogen-activated protein kinase (MAPK), nuclear translocation of 2 transcription factors, nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1), and time-dependent secretion of IL-8 from the macrophages. Inhibition of MAPKs and of transcription factors showed that p38 MAPK and NF-kappaB, but not ERK1/2, JNK, or AP-1, were crucial for the H-LDL-induced IL-8 secretion from the macrophages.

CONCLUSIONS

The results show that by activating p38 MAPK and NF-kappaB, macrophage hydrolases modify LDL into biologically active particles capable of triggering the secretion of IL-8 in macrophages. Thus, activated hydrolase-secreting macrophages in atherosclerotic lesions may sustain a proatherogenic extracellular environment by hydrolyzing LDL and triggering it to act in an autocrine or paracrine fashion to induce IL-8 secretion by the plaque macrophages.

Protein kinase D2 mediates lysophosphatidic acid-induced interleukin 8 production in nontransformed human colonic epithelial cells through NF-kappaB

The signaling pathways mediating lysophosphatidic acid (LPA)-stimulated PKD(2) activation and the potential contribution of PKD(2) in regulating LPA-induced interleukin 8 (IL-8) secretion in nontransformed, human colonic epithelial NCM460 cells were examined. Treatment of serum-deprived NCM460 cells with LPA led to a rapid and striking activation of PKD(2), as measured by in vitro kinase assay and phosphorylation at the activation loop (Ser706/710) and autophosphorylation site (Ser876). PKD(2) activation induced by LPA was abrogated by preincubation with selective PKC inhibitors GF-I and Ro-31-8220 in a dose-dependent manner. These inhibitors did not have any direct inhibitory effect on PKD(2) activity. LPA induced a striking increase in IL-8 production and stimulated NF-kappaB activation, as measured by NF-kappaB-DNA binding, NF-kappaB-driven luciferase reporter activity, and IkappaBalpha phosphorylation. PKD(2) gene silencing utilizing small interfering RNAs targeting distinct PKD(2) sequences dramatically reduced LPA-stimulated NF-kappaB promoter activity and IL-8 production. PKD(2) activation is a novel early event in the biological action of LPA and mediates LPA-stimulated IL-8 secretion in NCM460 cells through a NF-kappaB-dependent pathway. Our results demonstrate, for the first time, the involvement of a member of the PKD family in the production of IL-8, a potent proinflammatory chemokine, by epithelial cells.

Lipoproteins and mitogen-activated protein kinase signaling: a role in atherogenesis?

PURPOSE OF REVIEW

Lipoproteins play a critical role in the development of atherosclerosis, which might result partly from their capacity to induce specific intracellular signaling pathways. The goal of this review is to summarize the signaling properties of lipoproteins, in particular, their capacity to induce activation of mitogen-activated protein kinase pathways and the resulting modulation of cellular responses in blood vessel cells.

RECENT FINDINGS

Lipoproteins activate the extracellular signal-regulated kinase and p38 mitogen-activated protein kinase pathways in all blood vessel cell types. This may require lipoprotein docking to scavenger receptor B1, allowing transfer of cholesterol and sphingosine-1-phosphate to plasma membranes. Subsequent propagation of the signals probably requires the stimulation of G protein-coupled receptors, followed by the transactivation of receptor tyrosine kinases. Lipoprotein-induced extracellular signal-regulated kinase activity favors cell proliferation, whereas lipoprotein-induced p38 mitogen-activated protein kinase activity leads to cell hyperplasia and promotes cell migration. Some signaling pathways and cellular effects induced by lipoproteins have been observed in atherosclerotic plaques and therefore represent potential targets for the development of anti-atherosclerotic drugs.

SUMMARY

The main blood vessel cell types have the capacity to activate protein kinase pathways in the presence of lipoproteins. This induces cell proliferation, hyperplasia and migration, known to be dysregulated in atherosclerotic lesions.