Hypoxia-inducible factor (HIF-1alpha) and cyclooxygenase-2 (COX-2) have been implicated in the regulation of inflammatory-like processes that lead to angiogenesis and fibrotic disorders. Here we demonstrate that in human lung fibroblasts (HLFs) treated with mixed exposures to chemical and microbial stimuli, HIF-1alpha stabilization plays a pivotal role in the induction of COX-2 mRNA and protein, driving the release of vascular endothelial growth factor (VEGF) and proangiogenic and profibrotic chemokines. Upon costimulation with Ni and the mycoplasma-derived lipopeptide macrophage-activating lipopeptide-2 (MALP-2), there was a synergistic induction of CXCL1 and CXCL5 mRNA and protein release from HLF, as well as an enhanced response in VEGF compared to either stimulus alone. Consistent with our previous findings that Ni and MALP-2 stimulates the induction of CXCL8 via a COX-2-mediated pathway, CXCL1, CXCL5, and VEGF release were also regulated by COX-2. Ni induced the stabilization of HIF-1alpha protein in HLF, which was further enhanced in the presence of MALP-2. Depletion of HIF-1alpha using siRNA blocked COX-2 induction by Ni and MALP-2 along with the release of VEGF, CXCL1, CXCL5, and CXCL8. Our results indicate that Ni and MALP-2 interact to promote an angiogenic profibrotic phenotype in HLF. Moreover, these findings reveal a potential role for HIF-1alpha in mediating chemical-induced alterations in cellular response to microbial stimuli, modulating pulmonary inflammation and its consequences such as fibrosis and angiogenesis.

CXC chemokines are particularly significant for leukocyte infiltration in inflammatory diseases. Recent reports have shown that inflammation is one of potential pathogenic mechanisms for diabetic nephropathy. However, information on inflammation related with CXC chemokines in human Type 2 diabetic nephropathy still remains scarce. We measured urinary and serum levels of three CXC chemokines, CXCL5, CXCL8 and CXCL9, in 45 Type 2 diabetic patients (DM), 42 primary renal disease (PRD) patients and 22 healthy controls by enzyme-linked immunosorbent assay. Urinary levels of CXCL5, CXCL8 and CXCL9 in DM were significantly elevated compared to those in controls (P<.0001, P<.01, P<.001; respectively). They increased consistent with urinary albumin excretion rate (UAER) and correlated with UAER in partial correlation analyses (r=0.41, P<.01; r=0.40, P<.01; r=0.45, P<.01; respectively). Urinary levels of CXCL5 in DM were significantly interrelated to HbA(1c) (r=0.42, P<.01). On the other hand, PRD showed significant increased levels of urinary CXCL8 and CXCL9 compared to controls (P<.001, P<.01; respectively), and so did PRD as UAER increased. However, there were no significant elevations of urinary levels of CXCL5 in PRD in spite of the increased UAER. We found significant associations of UAER in DM with diabetes duration, 1/serum creatinine, urinary CXCL5 (adjusted R(2)=0.67, P<.0001) or CXCL9 (adjusted R(2)=0.69, P<.0001) in a stepwise multiple regression analysis. These results suggest that these three CXC chemokines may be involved in the progression of human Type 2 diabetic nephropathy and that CXCL5 may be of use for telling diabetic nephropathy from primary renal diseases.

OBJECTIVE

Adenosine is a major endogenous regulator of macrophage function, and activates four specific adenosine receptors (A(1), A(2A), A(2B) and A(3)). Here, we have assessed in human lung macrophages the modulation of the expression of adenosine receptor mRNA by lipopolysaccharide (LPS), and the relative contributions of the different adenosine receptors to LPS-induced production of tumour necrosis factor (TNF)-alpha and chemokines.

METHODS

Lung macrophages isolated from resected lungs were stimulated with LPS and treated with adenosine receptor agonists or/and antagonists. Adenosine receptor expression was assessed with qRT-PCR. Cytokines were measured in lung macrophage supernatants with elisa.

RESULTS

LPS increased (about 400-fold) mRNA for A(2A) adenosine receptors, decreased mRNA for A(1) and A(2B), but had no effect on A(3) adenosine receptor mRNA. The adenosine receptor agonist NECA inhibited TNF-alpha production concentration dependently, whereas the A(1) receptor agonist, CCPA, and the A(3) receptor agonist, AB-MECA, inhibited TNF-alpha production only at concentrations affecting A(2A) receptors. NECA also inhibited the production of CCL chemokines (CCL2, CCL3, CCL4, CCL5) and CXCL chemokines (CXCL9 and CXCL10), but not that of CXCL1, CXCL8 and CXCL5. Reversal of NECA-induced inhibition of TNF-alpha and chemokine production by the selective A(2A) adenosine receptor antagonist ZM 241385, but not the A(2B) receptor antagonist, MRS 1754, or the A(3) receptor antagonist, MRS 1220, indicated involvement of A(2A) receptors.

CONCLUSIONS

LPS up-regulated A(2A) adenosine receptor gene transcription, and this receptor subtype mediated inhibition of the LPS-induced production of TNF-alpha and of a subset of chemokines in human lung macrophages.

Gene expression profiling (GEP) of 8 stage 0/I untreated Chronic Lymphocytic Leukemia (CLL) patients showed over-expression of Frizzled 3 (FZD3)/ROR-1 receptor tyrosine kinase (RTK), FLT-3 RTK and CXCR3 G-protein coupled receptor (GPCR). RT-PCR of 24 genes in 21 patients of the WNT pathway corroborated the GEP. Transforming growth factorβ, fibromodulin, TGFβRIII and SMAD2 are also over-expressed by GEP. Serum cytokine profiling of 26 low stage patients showed elevation of IFNγ, CSF3, Flt-3L and insulin-like growth factor binding protein 4. In order to ascertain why CLL cells grow poorly in culture, a GEP of 4 CLL patients cells at 0 hr and 24 hr in culture demonstrated over expression of CXCL5, CCL2 and CXCL3, that may recruit immune cells for survival. Treatment with thalidomide, an immunomodulatory agent, showed elevation of CCL5 by GEP but was not cytotoxic to CLL cells. Our data suggest an interplay of several oncogenic pathways, cytokines and immune cells that promote a survival program in CLL.

Arrhythmogenic cardiomyopathy (AC) is an incurable genetic disease, whose pathogenesis is poorly understood. AC is characterized by arrhythmia, fibrosis, and cardiodilation that may lead to sudden cardiac death or heart failure. To elucidate AC pathogenesis and to design possible treatment strategies of AC, multiple murine models have been established. Among them, mice carrying desmoglein 2 mutations are particularly valuable given the identification of desmoglein 2 mutations in human AC and the detection of desmoglein 2 auto-antibodies in AC patients. Using two mouse strains producing either a mutant desmoglein 2 or lacking desmoglein 2 in cardiomyocytes, we test the hypothesis that inflammation is a major component of disease pathogenesis. We show that multifocal cardiomyocyte necrosis initiates a neutrophil-dominated inflammatory response, which also involves macrophages and T cells. Increased expression of Ccl2/Ccr2, Ccl3/Ccr5, and Cxcl5/Cxcr2 mRNA reflects the observed immune cell recruitment. During the ensuing acute disease phase, Mmp12⁺ and Spp1⁺ macrophages and T cells accumulate in scars, which mature from cell- to collagen-rich. The expression of Cx3cl1/Cx3cr1, Ccl2/Ccr2, and Cxcl10/Cxcr3 dominates this disease phase. We furthermore find that during chronic disease progression macrophages and T cells persist within mature scars and are present in expanding interstitial fibrosis. Ccl12 and Cx3cl1 are predominant chemokines in this disease phase. Together, our observations provide strong evidence that specific immune cell populations and chemokine expression profiles modulate inflammatory and repair processes throughout AC progression.

Keywords: Cardiomyopathy; Chronic disease progression; Desmoglein; Desmosome; Immune cells; Inflammation.

Impaired endothelial repair is a key contributor to microvascular rarefaction and consequent end-organ dysfunction in diabetes. Recent studies suggest an important role for bone marrow-derived early outgrowth cells (EOCs) in mediating endothelial repair, but the function of these cells is impaired in diabetes, as in advanced age. We sought to determine whether diabetes-associated EOC dysfunction might be attenuated by pharmacological activation of silent information regulator protein 1 (SIRT1), a lysine deacetylase implicated in nutrient-dependent life span extension in mammals. Despite being cultured in normal (5.5 mM) glucose for 7 days, EOCs from diabetic rats expressed less SIRT1 mRNA, induced less endothelial tube formation in vitro and neovascularization in vivo, and secreted less of the proangiogenic ELR(+) CXC chemokines CXCL1, CXCL3, and CXCL5. Ex vivo SIRT1 activation restored EOC chemokine secretion and increased the in vitro and in vivo angiogenic activity of EOC conditioned medium derived from diabetic animals to levels similar to that derived from control animals. These findings suggest a pivotal role for SIRT1 in diabetes-induced EOC dysfunction and that its pharmacologic activation may provide a new strategy for the restoration of EOC-mediated repair mechanisms.

BACKGROUND

A number of studies have suggested that angiotensin II (AII) receptor type 1 (ATR1) blocking drugs (ARBs) have anti-inflammatory effects however the mechanisms responsible are poorly investigated.

OBJECTIVE

To determine the role of extracellular signal regulated kinase (ERK)1/2 in ARB induced anti-inflammatory effects within human carotid atherosclerosis.

METHODS

Atheroma samples obtained from patients undergoing carotid endarterectomy were cultured with and without ATR1 (irbesartan), ERK1/2 (PD98059), AII ([Sar(1), Ile(8)]-AII) and angiotensin converting enzyme (ACE)2 (DX600) blockade. The in vitro effects of ATR1 and ERK1/2 blockade and exogenous AII on serum stimulated healthy, primary vascular cells were also investigated. Outcome was assessed by measuring cytokine, (interleukin (IL)-6, IL-8, C-C motif chemokine (CCL)2, C-X-C motif chemokine (CXCL)5, osteoprotegerin (OPG), osteopontin (OPN), CXCL16), concentrations in supernatants and phosphorylated ERK1/2 in the tissue lysates using ELISA. ERK1/2 expression in the tissue was assessed using Western blotting.

RESULTS

Irbesartan reduced concentrations of IL-6, IL-8, CCL2, CXCL5, OPG, OPN and CXCL16 in both atheroma and primary vascular cell culture supernatants. The reduction in cytokine levels in the atheroma supernatant was correlated to a reduction in ERK1/2 expression in the tissue. Inhibition of ERK1/2 downregulated IL-6, IL-8 and CXCL5 in both atheroma and cell culture supernatants. AII and ACE2 blockade had no impact on cytokine or active ERK1/2 levels in the atheroma culture.

CONCLUSIONS

Our findings suggest that ATR1 blockade downregulates atheroma tissue ERK1/2 expression leading to a reduction in cytokine production and that a non-AII agonist ATR1 signalling response may induce expression of these inflammation associated cytokines in the atheroma.

Previous work from our laboratory has demonstrated overexpression of chemokines in head and neck cancer and the utility of targeting these proteins for tumor therapy in a preclinical model. However, the mechanisms involved are unexplored. Through gene expression analysis, we found that expression of vascular endothelial growth factor (VEGF-C) was elevated in HN12 cells expressing high levels of CXCL5. In the present study, we have investigated the contribution of VEGF-C to tumor cell growth and motility. RNAi-mediated knockdown of VEGF-C expression in HN12 cells, which express high levels of CXCL5, resulted in a decrease in proliferation. Conversely, forced expression of VEGF-C in HN4 tumor cells with low endogenous CXCL5 levels increased cell growth. Suppression of VEGF-C inhibited migration of HN12 cells. Similarly, HN4 cells showed reduced migration towards conditioned media collected from HN12 cells with VEGF-C knockdown compared to controls, while HN4/VEGF-C conditioned media stimulated cell migration. Moreover, tumor growth in vivo was markedly reduced when VEGF-C expression was blocked by shRNA. Finally, determination of VEGF-C expression in squamous carcinoma cell lines revealed universal overexpression compared to normal keratinocytes. These findings support a role for VEGF-C in head and neck squamous cell carcinogenesis.

BACKGROUND

Adipokines are bioactive hormones secreted by adipose tissues. Resistin, an adipokine, plays important roles in the regulation of insulin resistance and inflammation. Resistin levels are known to be increased in the serum and synovial fluid of rheumatoid arthritis (RA) patients. However, the pathogenic role of resistin in RA has not yet been elucidated.

METHODS

The expression of resistin and adenylate cyclase-associated protein 1 (CAP1), a receptor for resistin, was examined immunohistochemically in synovial tissue. CAP1 expression in in vitro cultured fibroblast-like synoviocytes (FLSs) was assessed with a reverse transcription-polymerase chain reaction (PCR) and western blotting. The gene expression of resistin-stimulated FLSs was evaluated by RNA sequencing (RNA-Seq) and quantitative real-time PCR. Concentrations of chemokine (C-X-C motif) ligand (CXCL) 8, chemokine (C-C motif) ligand (CCL) 2, interleukin (IL)-1β, IL-6 and IL-32 in culture supernatants were measured by enzyme-linked immunosorbent assay. Small interfering RNA (siRNA) for CAP1 was transfected into FLSs in order to examine inhibitory effects.

RESULTS

The expression of resistin and CAP1 in synovial tissue was stronger in RA than in osteoarthritis (OA). Resistin was expressed by macrophages in the RA synovium, while CAP1 was expressed by macrophages, FLSs and endothelial cells. In vitro cultured RA FLSs also expressed CAP1. RNA-Seq revealed that the expression levels of 18 molecules were more than twofold higher in resistin-stimulated FLSs than in unstimulated FLSs. Seven chemokines, CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL8, and CCL2, were included among the 18 molecules. Increases induced in the expression of CXCL1, CXCL8, and CCL2 by the resistin stimulation were confirmed by real-time PCR. The stimulation with resistin increased the protein levels of CXCL8 and CCL2 produced by RA FLSs, and the upregulated expression of CXCL8 was inhibited by the abrogation of CAP1 by siRNA for CAP1. Production of IL-6 by FLSs was also increased by resistin. Expression of IL-1β and IL-32 was not detected by ELISA.

CONCLUSIONS

Resistin contributes to the pathogenesis of RA by increasing chemokine production by FLSs via CAP1 in synovial tissue.

Individuals with inflammatory bowel disease are at high risk of developing colitis-associated cancer (CAC). Strategies to block the process from inflammatory bowel disease to CAC should be considered. In the experiment, we aim to explore the chemopreventive efficacy of the probiotic cocktail Bifico and its potential mechanism in azoxymethane and dextran sodium sulphate-induced CAC in mice. Oral pretreatment of Bifico was adopted to evaluate its protective effect. The colorectums of 35 C57BL/6 mice were collected and examined for the degree of inflammation and tumorigenesis. Comparative 16S rRNA sequencing was carried out to observe Bifico-target alterations in gene expression and microbiota structure. We found that pretreatment of Bifico alleviated intestinal inflammation and reduced tumor formation. Furthermore, we identified a subset of genes as potential targets of Bifico treatment, including CXCL1, CXCL2, CXCL3, and CXCL5, which are all ligands of C-X-C motif receptor 2 (CXCR2). The 16S rRNA sequencing showed that Bifico decreased the abundance of genera Desulfovibrio, Mucispirillum, and Odoribacter, and a bloom of genus Lactobacillus was detected. Notably, we found that an abundance of these Bifico-target taxa was significantly associated with the expression of CXCR2 ligand genes. Our studies indicate that Bifico, given orally, can ameliorate CAC in mice through intervening with the possible link between Desulfovibrio, Mucispirillum, Odoribacter, Lactobacillus, and CXCR2 signaling.

Myeloid-derived suppressor cells (MDSCs) expand in tumor-bearing host. They suppress anti-tumor immune response and promote tumor growth. Chemokines play a vital role in recruiting MDSCs into tumor tissue. They can also induce the generation of MDSCs in the bone marrow, maintain their suppressive activity, and promote their proliferation and differentiation. Here, we review CCL2/CCL12-CCR2, CCL3/4/5-CCR5, CCL15-CCR1, CX3CL1/CCL26-CX3CR1, CXCL5/2/1-CXCR2, CXCL8-CXCR1/2, CCL21-CCR7, CXCL13-CXCR5 signaling pathways, their role in MDSCs recruitment to tumor tissue, and their correlation with tumor development, metastasis and prognosis. Targeting chemokines and their receptors may serve as a promising strategy in immunotherapy, especially combined with other strategies such as chemotherapy, cyclin-dependent kinase or immune checkpoints inhibitors.

We have recently shown that the CXCL5 chemokine is secreted by adipose tissue in the obese state. We demonstrated that adipose tissue-derived CXCL5 mediates insulin resistance in muscle. We speculate in this paper that CXCL5 could also mediate other obesity, and diabetes-derived pathologies, such as cardiovascular disease, retinopathy, or inflammatory bowel disease. In this scenario CXCL5 targeted therapy would prevent not only the development of type II diabetes in obese subjects, but also several other obesity-related co morbidities. Finally we propose to analyze the CXCL5 gene to find particular polymorphisms that could predict the development of type II diabetes in obese subjects.

African American (AA) women are more likely than European American (EA) women to be diagnosed with early, aggressive breast cancer. Possible differences in innate immune pathways (e.g., inflammatory responses) have received little attention as potential mechanisms underlying this disparity. We evaluated distributions of selected genetic variants in innate immune pathways in AA and EA women, and examined their associations with breast cancer risk within the Women's Circle of Health Study (WCHS). In stage I of the study (864 AA and 650 EA women) we found that genotype frequencies for 35 of 42 tested SNPs (18 candidate genes) differed between AAs and EAs (corroborated by ancestry informative markers). Among premenopausal AA women, comparing variant allele carriers to non-carriers, reduced breast cancer risk was associated with CXCL5-rs425535 (OR=0.61, P=0.02), while among EA women, there were associations with TNFA-rs1799724 (OR =2.31, P =0.002) and CRP-rs1205 (OR=0.54, P=0.01). For postmenopausal women, IL1B-rs1143627 (OR=1.80, P=0.02) and IL1B-rs16944 (OR=1.85, P =0.02) were associated with risk among EA women, with significant associations for TNFA-rs1799724 limited to estrogen receptor (ER) positive cancers (OR=2.0, P =0.001). However, none of the SNPs retained significance after Bonferroni adjustment for multiple testing at the level of P0.0012 (0.05/42) except for TNFA-rs1799724 in ER positive cancers. In a stage II validation (1,365 AA and 1,307 EA women), we extended evaluations for four SNPs (CCL2-rs4586, CRP-rs1205, CXCL5-rs425535, and IL1RN-rs4251961), which yielded similar results. In summary, distributions of variants in genes involved in innate immune pathways were found to differ between AA and EA populations, and showed differential associations with breast cancer according to menopausal or ER status. These results suggest that immune adaptations suited to ancestral environments may differentially influence breast cancer risk among EA and AA women.

BACKGROUND

Diabetes mellitus as the most prevalent metabolic disease is a multifactorial disease which is influenced by environmental and genetic factors. In this systematic review, we assessed the association between genetic variants and diabetes/its complications in studies with Iranian populations.

METHODS

Google Scholar, PubMed, Scopus, and Persian web databases were systematically searched up to January 2014. The search terms were "gene," "polymorphism," "diabetes," and "diabetic complications"; nephropathy, retinopathy, neuropathy, foot ulcer, and CAD (coronary artery diseases); and Persian equivalents. Animal studies, letters to editor, and in vitro studies were excluded.

RESULTS

Out of overall 3029 eligible articles, 88 articles were included. We found significant association between CTLA-4, IL-18, VDR, TAP2, IL-12, and CD4 genes and T1DM, HNFα and MODY, haptoglobin, paraoxonase, leptin, TCF7L2, calreticulin, ERα, PPAR-γ2, CXCL5, calpain-10, IRS-1 and 2, GSTM1, KCNJ11, eNOS, VDR, INSR, ACE, apoA-I, apo E, adiponectin, PTPN1, CETP, AT1R, resistin, MMP-3, BChE K, AT2R, SUMO4, IL-10, VEGF, MTHFR, and GSTM1 with T2DM or its complications.

CONCLUSIONS

We found some controversial results due to heterogeneity in ethnicity and genetic background. We thought genome wide association studies on large number of samples will be helpful in identifying diabetes susceptible genes as an alternative to studying individual candidate genes in Iranian populations.

An indispensable role for oligodendrocytes in the protection of axon function and promotion of neuronal survival is strongly supported by the finding of progressive neuron/axon degeneration in human neurological diseases that affect oligodendrocytes. Imaging and pathological studies of the CNS have shown the presence of neuroaxonal injury in progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the CNS, resulting from destruction of oligodendrocytes upon productive replication of the pathogenic neurotropic polyomavirus JC. Here, we examined the extracellular factors involved in communication between oligodendrocytes and neurons. Culturing cortical neurons with conditioned medium (CM) from rat CG4 oligodendrocytic cells that express the JCV agnoprotein showed that CXCL5/LIX, which is a chemokine closely related to the human CXCL5/ENA78 and CXCL6/GCP-2 chemokines, is essential for neuronal cell survival. We found that in CM from agnoprotein-producing CG-4 cells level of CXC5/LIX is decreased compared to control cells. We also demonstrated that a reduced expression of CXCL5/LIX by CG4 GFP-Agno cells triggered a cascade of signaling events in cortical neurons. Analysis of mitogen-activated protein kinases (MAPK) and glycogen synthase kinase (GSK3) pathways showed that they are involved in mechanisms of neuronal apoptosis in response to the depletion of CXCL5/LIX signaling. These data suggest that agnoprotein-induced dysregulation of chemokine production by oligodendrocytes may contribute to neuronal/axonal injury in the pathogenesis of PML lesions.

Transplantation of allogeneic grafts presents several challenges to the innate and adaptive immune systems including chemokine leukocyte recruitment, activation, and effector function. We defined the chemokines and receptors induced by the transplant procedure/ischemia injury, alloantigen and gene transfer vector administration in murine cardiac grafts. E1, E3 deleted AdRSVbetagal was transferred into grafts at the time of transplantation, grafts were harvested after 1-14 days, and a pathway-specific cDNA array was used to evaluate the levels of 67 chemokine and chemokine receptor genes. Transplantation resulted in ischemic injury and induction of a number of similar genes in both the syngeneic and allogeneic grafts, such as CXCL1 and CXCL5, which increased dramatically on day 1 and returned rapidly to baseline in the syngeneic grafts. Alloantigen stimulated the adaptive immune response and induced the presence of more inflammatory genes within the grafts, particularly at later time points. The adenovirus vector induced a broader panel of genes, among them potent inflammatory chemokines CXCL9 and CXCL10, that are induced earlier or more strongly compared with alloantigen stimulation alone. As alloantigen and adenovirus vectors both induce similar sets of genes, targeting these molecules may not only inhibit alloimmunity, but also enhance the utility of the gene transfer vector.

CXCL5 and its receptor CXCR2 have been found to be involved in tumorigenesis and cancer progression. Recent studies have shown that CXCR2 is upregulated in glioma tissues, and associated with poor prognosis and recurrence. However, the role of CXCL5/CXCR2 signaling in mediating the malignant phenotypes of glioma cells, as well as the underlying mechanism, still remains unclear. In the present study, we found that CXCL5 was upregulated in glioma tissues compared to that noted in normal brain tissues. High CXCL5 levels were significantly associated with higher tumor grade, advanced clinical stage, and shorter survival time of glioma patients. In vitro studies indicated that the protein expression levels of CXCL5 and CXCR2 were markedly higher in human glioma cell lines (U87, U251, U373 and A172), when compared with those in normal human gliocyte HEB cells. Overexpression of CXLC5 significantly promoted the proliferation and migration of U87 cells, while knockdown of CXCL5 by small interfering RNA markedly inhibited U87 cell proliferation and migration. Moreover, both exogenous CXCL5 treatment and the conditioned medium of CXCL5-overexpressing HEB cells also enhanced the proliferation and migration of U87 cells. Molecular mechanism investigation revealed that CXLC5 activated the ERK, JNK, p38 MAPK signaling pathways, which play key roles in tumor growth and metastasis. According to these data, our study suggests that CXCL5 plays a promoting role in glioma in autocrine- and paracrine-dependent manners.

The expression profiling analysis of inflammatory chemokines and their receptors in newly formed lymph nodes in breast cancer was carried out. The analysis revealed the increase in expression of the genes CCL16, XCR1, CYFIP2, TNFSF14 and the reduction in expression of chemokine ligands CXCL5 and CXCL12 in tertiary lymphoid organs. The obtained results allow us to suggest that the process of induction of lymph nodes neogenesis is identical (in its key mechanisms) to the process of lymphoid tissue neogenesis in autoimmune diseases and in some infections, but may have different triggers.

Ovarian cancer is an insidious and aggressive disease of older women, typically undiscovered before peritoneal metastasis due to its asymptomatic nature and lack of early detection tools. Epidemiologic studies suggest that child-bearing (parity) is associated with decreased ovarian cancer risk, although the molecular mechanisms responsible for this phenomenon have not been delineated. Ovarian cancer preferentially metastasizes to the omental fat band (OFB), a secondary lymphoid organ that aids in filtration of the peritoneal serous fluid (PSF) and helps combat peritoneal infections. In the present study, we assessed how parity and age impact the immune compositional profile in the OFB of mice, both in the homeostatic state and as a consequence of peritoneal implantation of ovarian cancer. Using fluorescence-activated cell sorting analysis and quantitative real-time PCR, we found that parity was associated with a significant reduction in omental monocytic subsets and B1-B lymphocytes, correlating with reduced homeostatic expression levels of key chemoattractants and polarization factors (Ccl1, Ccl2, Arg1, and Cxcl13). Of note, parous animals exhibited significantly reduced tumor burden following intraperitoneal implantation compared with nulliparous animals. This was associated with a reduction in tumor-associated neutrophils and macrophages, as well as in the expression levels of their chemoattractants (Cxcl1 and Cxcl5) in the OFB and PSF. These findings define a preexisting "parity-associated microenvironmental niche" in the OFB that is refractory to metastatic tumor seeding and outgrowth. Future studies designed to manipulate this niche may provide a novel means to mitigate peritoneal dissemination of ovarian cancer.

Previous pneumococcal experience establishes lung-resident IL-17A-producing CD4⁺ memory T_RM cells that accelerate neutrophil recruitment against heterotypic pneumococci. Herein, we unravel a novel crosstalk between CD4⁺ T_RM cells and lung epithelial cells underlying this protective immunity. Depletion of CD4⁺ cells in pneumococcus-experienced mice diminished CXCL5 (but not CXCL1 or CXCL2) and downstream neutrophil accumulation in the lungs. Epithelial cells from experienced lungs exhibited elevated mRNA for CXCL5 but not other epithelial products such as GM-CSF or CCL20, suggesting a skewing by CD4⁺ T_RM cells. Genome-wide expression analyses revealed a significant remodeling of the epithelial transcriptome of infected lungs due to infection history, ~80% of which was CD4⁺ cell-dependent. The CD4⁺ T_RM cell product IL-17A stabilized CXCL5 but not GM-CSF or CCL20 mRNA in cultured lung epithelial cells, implicating posttranscriptional regulation as a mechanism for altered epithelial responses. These results suggest that epithelial cells in experienced lungs are effectively different, owing to their communication with T_RM cells. Our study highlights the role of tissue-resident adaptive immune cells in fine-tuning epithelial functions to hasten innate immune responses and optimize defense in experienced lungs, a concept that may apply broadly to mucosal immunology.

Failure after glaucoma filtration surgery is attributed to fibrosis at the operated site. To understand the wound healing process after glaucoma filtration surgery, we have developed a mouse model for glaucoma filtration surgery which closely mimics the clinical response. In this study, we describe a systematic analysis of the wound healing response in vivo. Our data revealed that the post-surgical tissue response was separable into two distinguishable phases. The early "acute inflammatory" phase was characterized by significantly increased transcript expression of Vegfa, Cxcl1, Cxcl5, Ccl2, Ccl3, Ccl4, Gmcsf and specific Mmps as well as greater infiltration of monocytes/macrophages and T cells. The late "fibrotic" phase was characterized by an increased expression of Tgfb2 and extracellular matrix genes as well as a notable reduction of infiltrating inflammatory cells. Significantly, more mitotic cells were observed at both time points post-surgery. Subconjunctival fibroblasts may be involved in both phases since they have the capacity to reiterate the in vivo gene expression profiles upon either pro-inflammatory or pro-fibrotic cytokine stimulation. Given that the cellular and molecular targets that govern the early and late phases of wound healing are distinct and time sensitive, a multi-targeted therapeutic approach to sequentially inhibit inflammation and fibrogenesis at the critical time point may lead to improved surgical outcomes in glaucoma filtration surgery.

OBJECTIVE

To identify disease-specific cytokine profile differences in the aqueous humor (AH) (other than the vascular endothelial growth factor) between patients with dry and treated wet age-related macular degeneration (AMD) and healthy controls.

METHODS

This retrospective study drew on a case-series of patients diagnosed with dry AMD (n = 25) and treated wet AMD (n = 19), as well as on healthy controls (no systemic therapy; n = 20) undergoing phacoemulsification or vitrectomy. Samples of AH and serum were collected in parallel at the beginning of surgery. The levels of 43 cytokines were simultaneously determined using the Bio-Plex® multiplex beads system. Differences between the three groups were statistically compared using the Kruskal-Wallis H-Test after applying the Bonferroni correction for multiple comparisons (p<0.0012).

RESULTS

The concentrations of three cytokines were elevated in the AH of patients with dry AMD (CXCL6; p = 0.00067) and treated wet AMD (CXCL5, CXCL6, MIG/XCXL; all p<0.001) relative to those in the healthy controls. No other differences between the three groups were identified. The AH levels of seven cytokines (16%), including CXCL6, ranged below the lower limit of quantitation of the assay. Without the correction for multiple comparisons (p<0.05), the levels of 31 of the 43 cytokines in the AH of patients with AMD would have differed significantly from those in the control. The systemic cytokine profiles (serum) were similar in all three groups.

CONCLUSIONS

No systematic differences in the AH cytokine environment were identified between patients with dry AMD and those with treated wet AMD. This finding might indicate that AMD is either the result of a persistent imbalance in the physiological tissue milieu, or that the localized process induces no significant change in the cytokine environment of the anterior ocular segment.

The mechanisms underlying the role of CXCL5 in tumor angiogenesis have not been fully defined. Here, we examined the effect of CXCL5 on tumor angiogenesis in colorectal cancer (CRC). Immunohistochemistry was used to monitor the expression of CXCL5 and CD31 in CRC patients' tissues. HUVEC cell lines stably transfected with shCXCR2 and shFOXD1 lentivirus plasmids were used in an in vitro study. Based on some molecular biological experiments in vitro and in vivo, we found that CXCL5 was upregulated in tumor tissues and that its level positively correlated with the expression of CD31. Next, we used recombinant human CXCL5 (rhCXCL5) to stimulate HUVECs and found that their tube formation ability, proliferation, and migration were enhanced by the activation of the AKT/NF-κB/FOXD1/VEGF-A pathway in a CXCR2-dependent manner. However, silencing of CXCR2 and FOXD1 or inhibition of the AKT and NF-κB pathways could attenuate the tube formation ability, proliferation, and migration of rhCXCL5-stimulated HUVECs in vitro. rhCXCL5 can promote angiogenesis in vivo in Matrigel plugs, and the overexpression of CXCL5 can also increase microvessel density in vivo in a subcutaneous xenotransplanted tumor model in nude mice. Taken together, our findings support CXCL5 as an angiogenic factor that can promote cell metastasis through tumor angiogenesis in CRC. Furthermore, we propose that FOXD1 is a novel regulator of VEGF-A. These observations open new avenues for therapeutic application of CXCL5 in tumor anti-angiogenesis.

Transforming growth factor (TGF)-β suppresses early hepatocellular carcinoma (HCC) development but triggers pro-oncogenic abilities at later stages. Recent data suggest that the receptor tyrosine kinase Axl causes a TGF-β switch towards dedifferentiation and invasion of HCC cells. Here, we analyzed two human cellular HCC models with opposing phenotypes in response to TGF-β. Both HCC models showed reduced proliferation and clonogenic growth behavior upon TGF-β stimulation, however, exhibited differences in chemosensitivity and migratory abilities, suggesting that HCC cells evade traits of anti-oncogenic TGF-β. Transcriptome profiling revealed differential regulation of the chemokine CXCL5, which positively correlated with TGF-β expression in HCC patients. The expression and secretion of CXCL5 was dependent on Axl expression suggesting that CXCL5 is a TGF-β target gene collaborating with Axl signaling. Loss of either TGF-β or Axl signaling abrogated CXCL5-dependent attraction of neutrophils. In mice, tumor formation of transplanted HCC cells relied on CXCL5 expression. In HCC patients, high levels of Axl and CXCL5 correlated with advanced tumor stages, recruitment of neutrophils into HCC tissue and reduced survival.

CONCLUSIONS

The synergy of TGF-β and Axl induces CXCL5 secretion causing the infiltration of neutrophils into HCC tissue. Intervention with TGF-β/Axl/CXCL5 signaling may be an effective therapeutic strategy to combat HCC progression in TGF-β-positive patients. This article is protected by copyright. All rights reserved.