Chemokine Profiles Are Affected in Serum of Patients with Acute Rejection of Kidney Allograft.

Kidney allograft transplantation improved the prognosis and quality of life of patients with end-stage renal diseases but the occurrence of acute rejection represents a limitation of the final outcome. Noninvasive biomarkers are needed as well as further advancements in the understanding of immune mechanisms of reaction to the allograft. Our study of 138 patients focused on one-year monitoring of serum concentrations of 12 chemokines regulating the recruitment of different immune cells into transplanted allograft and on in vitro regulation of the same chemokines release by interactions of renal proximal epithelial cells with monocyte/macrophage cell line stimulated with TNF alpha. In a group of 44 patients with acute rejection, higher serum pretransplant levels of CXCL1, CXCL5, CXCL6, CCL2, CCL21, and particularly CXCL10 and CX3CL1(both p < 0.001) were found suggesting their higher proinflammatory status as compared to subjects with the uncomplicated outcome. In samples collected at the day of biopsy positive for acute rejection, chemokines CXCL9 and CXCL11 attracting preferentially Th1 lymphocytes were found to be upregulated. In our in vitro model with TNF alpha induction, renal proximal epithelial cells seemed to be a more potent source of chemokines attracting neutrophils as compared to monocyte/macrophage cell line but the coculture of these cells potentiated release of neutrophilic chemokines CXCL5 and CXCL6. Similar augmentation of chemokine production was found also in the case of CCL2. On the other hand, adding of monocytes/macrophages to a culture of renal epithelial cells suppressed the release of CXCL10 and CXCL11 attracting T lymphocytes. We assume from our data that in kidney allograft transplantation, chemokines attracting neutrophils, T lymphocytes, and monocytes are induced simultaneously and measurement some of them in combination might be used as biomarkers of acute rejection. Mutual cell-cell interactions of immune cells with renal parenchyma seem to be important for fine regulation of chemokine release.

Diagnostic value of GCP-2/CXCL-6 and hs-CRP in the diagnosis of acute appendicitis.

BACKGROUND: Acute appendicitis (AA) is one of the major causes of acute abdomen pain. Various laboratory markers have been studied for diagnosis of AA, but none of them have shown superiority to physical examination or imaging. GCP-2/CXCL6 is a chemokine expressed by macrophages and epithelial and mesenchymal cells during inflammation. The present study aims to investigate the diagnostic role of GCP-2/CXCL6 in AA patients. METHODS: In this cross-sectional study, the serum level of GCP-2/CXCL6 was measured in 56 AA patients and 32 healthy control subjects. Also, hs-CRP and white blood cell count (WBC) levels of the patient and control groups were evaluated. RESULTS: GCP-2/CXCL-6, hs-CRP and WBC levels of the AA group were significantly higher than the control group (p<0.05 for all comparisons). Among AA group, GCP-2/CXCL6 levels were higher in complex AA (gangrenous, abscess and perforation) ones when compared to non-complex AA (p<0.05). A strong positive correlation was found between GCP-2/CXCL6 levels and hs-CRP levels (r=0.756, p=0.003) and a moderate positive correlation between GCP-2/CXCL6 levels and WBC count (r=0.468, p=0.003). CONCLUSION: GCP-2/CXCL6 can be a useful marker in AA diagnosis and discrimination of complex cases, especially if combined with other laboratory markers and imaging techniques.

Identifying the molecular and cellular signature of cardiac dilation following myocardial infarction.

Establishing molecular and cellular indicators that reflect the extent of dilation of the left ventricle (LV) after myocardial infarction (MI) may improve diagnostic and prognostic capabilities. We queried the Mouse Heart Attack Research Tool (mHART) 1.0 for day 7 post-MI mice (age 3-9 months, untreated males and females) with serial echocardiographic data at days 0, 1, and 7 (n = 51). Mice were classified into two subgroups determined by a median fold change of 1.6 in end-diastolic dimensions (EDD) normalized to pre-MI values; n = 26 fell below (moderate; mean of 1.42 ±â€¯0.01) and n = 25 fell above this cut-off (extreme; mean of 1.79 ±â€¯0.01; p < 0.001 vs. moderate). Plasma proteomic profiling of 34 analytes measured at day 7 post-MI from male mice (n = 12 moderate and 12 extreme) were evaluated as the test dataset, and receiver operating curve (ROC) analysis was used to assess strength of biomarkers. Females (n = 6 moderate and 9 extreme) were used as the validation dataset. Both by t-test and characteristic (ROC) curve analysis, lower macrophage inflammatory protein-1 gamma (MIP-1γ), lymphotactin, and granulocyte chemotactic protein-2 (GCP-2) were identified as plasma indicators for dilation status (p < 0.05 for all). Macrophage numbers were decreased and complement C5, laminin 1, and Ccr8 gene levels were significantly higher in the LV infarcts of the extreme dilation group (p < 0.05 for all). A composite panel including plasma MIP-1γ, lymphotactin, and GCP-2, and LV infarct Ccr8 and macrophage numbers strongly mirrored LV dilation status (AUC = 0.92; p < 0.0001). Using the mHART 1.0 database, we determined that a failure to mount sufficient macrophage-mediated inflammation was indicative of exacerbated LV dilation.

Neutrophil chemokines levels in different stages of nephrotic syndrome.

Nephrotic syndrome (NS) is a disease of glomerular filtration barrier failure presenting with variable degrees of proteinuria, hypoalbuminemia, hyperlipidemia, and edema. Inflammation may contribute to the pathogenesis of NS. The aim of this study was to monitor the serum levels of three cytokines [i.e., granulocyte chemotactic protein-2 (GCP-2), growth-related oncogene-α (GRO-α), and interleukin-8 (IL-8)] in different stages of NS and to find out whether changes in the levels of these cytokines could be related to the severity of NS. This study included 125 patients who were divided into 40 patients with nephrotic range proteinuria (NRP), 45 patients with NS, and 40 patients who were in remission. This study also included 80 healthy participants as a control group. Enzyme-linked immunosorbent assay was used for the determination of the plasma levels of GRO-α, GCP-2, and IL-8. GCP-2 plasma levels were significantly higher in the NS and NRP groups when compared to the control group, whereas the GRO-α and IL-8 levels were significantly higher in all patient groups in comparison with the control group. All these chemokine levels were significantly decreased in remission as compared with the participants in the NS group (P <0.0001). There was a significant correlation between the cytokine levels and proteinuria and serum albumin in the NS group (P <0.0001). However, in the follow-up group, GCP-2 levels were significantly lower during remission as compared to those with active NS (P <0.0001). Our findings suggest that the pro-inflammatory cytokines GCP-2, GRO-α, and IL-8 could play a role in the pathogenesis of NS, particularly glomerular permeability.

Associations Between Macrophage Colony-Stimulating Factor and Monocyte Chemotactic Protein 1 in Plasma and First-Time Coronary Events: A Nested Case-Control Study.

BACKGROUND: Myeloid cells play a central role in atherosclerosis. We investigated the associations between the plasma levels of growth factors and chemokines that regulate myeloid cell homeostasis and function and the risk of first-time acute coronary events in middle-aged persons. METHODS AND RESULTS: We measured baseline plasma levels of macrophage colony-stimulating factor; monocyte chemotactic protein 1; C-C motif chemokine ligands 3, 4, and 20; C-X-C motif chemokine ligands 1, 6, and 16; and C-X3-C motif chemokine ligand 1 in 292 participants who had a coronary event during follow-up and 366 controls matched for age, sex, and time of inclusion who remained event free. Study participants were recruited from the Malmö Diet and Cancer Study population cohort and had no previous history of coronary artery disease. We found a strong independent negative association between macrophage colony-stimulating factor and incident coronary events in a forward stepwise Cox proportional hazards model including all biomarkers alongside the classic Framingham risk factors (age, sex, smoking, total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure), diabetes mellitus, and medication. Conversely, monocyte chemotactic protein 1 had the strongest independent positive association with the outcome. The addition of macrophage colony-stimulating factor and monocyte chemotactic protein 1 significantly improved the predictive ability of a model including traditional risk factors alone (C statistic 0.81 [95% CI 0.78-0.84] versus 0.67 [95% CI 0.63-0.71]; net reclassification index 0.52 [0.42-0.62]; P<0.001). The combined model led to a 54% net downclassification of participants who did not have a coronary event during follow-up and was particularly effective in the intermediate-risk group. CONCLUSIONS: High levels of macrophage colony-stimulating factor and low levels of monocyte chemotactic protein 1 in plasma characterize middle-aged persons at low risk to develop clinically manifested coronary artery disease.

Disease-specific dynamic biomarkers selected by integrating inflammatory mediators with clinical informatics in ARDS patients with severe pneumonia.

Acute respiratory distress syndrome (ARDS) is a heterogeneous syndrome that occurs as a result of various risk factors, including either direct or indirect lung injury, and systemic inflammation triggered also by severe pneumonia (SP). SP-ARDS-associated morbidity and mortality remains high also due to the lack of disease-specific biomarkers. The present study aimed at identifying disease-specific biomarkers in SP or SP-ARDS by integrating proteomic profiles of inflammatory mediators with clinical informatics. Plasma was sampled from the healthy as controls or patients with SP infected with bacteria or infection-associated SP-ARDS on the day of admission, day 3, and day 7. About 15 or 52 cytokines showed significant difference between SP and SP-ARDS patients with controls or 13 between SP-ARDS with SP alone and controls, including bone morphogenetic protein-15 (BMP-15), chemokine (C-X-C motif) ligand 16 (CXCL16), chemokine (C-X-C motif) receptor 3 (CXCR3), interleukin-6 (IL-6), protein NOV homolog (NOV/CCN3), glypican 3, insulin-like growth factor binding protein 4 (IGFBP-4), IL-5, IL-5 R alpha, IL-22 BP, leptin, MIP-1d, and orexin B with a significant correlation with Digital Evaluation Score System (DESS) scores. ARDS patients with overexpressed IL-6, CXCL16, or IGFBP-4 had significantly longer hospital stay and higher incidence of secondary infection. We also found higher levels of those mediators were associated with poor survival rates in patients with lung cancer and involved in the process of the epithelial mesenchymal transition of alveolar epithelial cells. Our preliminary study suggested that integration of proteomic profiles with clinical informatics as part of clinical bioinformatics is important to validate and optimize disease-specific and disease-staged biomarkers.

Systemic blood plasma CCL5 and CXCL6: Potential biomarkers for human lumbar disc degeneration.

Lumbar disc degeneration severity on magnetic resonance imaging (MRI) is associated with low back pain. Pro-inflammatory chemokines CCL5 and CXCL6 are released by induced degenerative discs, and CCL5 has been associated with discogenic back pain. A case-control study was performed, based on the Hong Kong Disc Degeneration Population-Based Cohort of Southern Chinese, to investigate if systemic levels of CCL5 and CXCL6 were elevated in subjects with disc degeneration compared to non-degenerated individuals. Eighty subjects were selected, 40 with no disc degeneration (control group; DDD score 0) and 40 with moderate/severe disc degeneration (disc degeneration group; DDD score ≥5) as noted on MRI. Subjects were matched for age, sex, body mass index and workload. Blood plasma samples were obtained from each individual, and levels of CCL5 and CXCL6 were measured. Secondary phenotypes of lumbar disc displacement and cervical disc changes were also assessed. CCL5 concentrations were significantly increased in the disc degeneration (mean: 19.8 ng/mL) compared to the control group (mean: 12.8 ng/mL) (p = 0.015). The degeneration group demonstrated higher levels of CXCL6 (mean: 56.9 pg/mL) compared to the control group (mean: 43.4 pg/mL) (p = 0.010). There was a trend towards elevated CCL5 levels with disc displacement in the degeneration group (p = 0.073). Cervical disc degeneration was not associated with elevated chemokine levels (p > 0.05). This is the first study to note that elevated systemic CCL5 and CXCL6 were associated with moderate/severe lumbar disc degeneration, further corroborating tissue studies of painful discs. These chemokines may be systemic biomarkers for the diagnosis and monitoring of disc degeneration.

The chemokine ligand CXCL16 is an indicator of bacterial infection in necrotizing pancreatitis.

OBJECTIVES: Current guidelines tell us that intervention in severe necrotizing pancreatitis ought to be performed as late as possible. However, when pancreatic necrosis becomes infected, the necrotic tissue needs to be removed. Unfortunately, bacterial infection can only be proven by invasive methods. METHODS: Necrotizing pancreatitis with sterile or infected necrosis was induced in mice. Mice serum samples were examined by antibody-based protein array. After identifying candidate proteins that showed strong regulation, the serum concentration of these proteins was examined by sandwich ELISA. Then, human serum samples were collected from patients with mild pancreatitis, severe pancreatitis with and without pancreatic necrosis and patients with microbiologically proven infection of pancreatic necrosis. These serum samples were then analyzed by sandwich ELISA. RESULTS: In mice 6 proteins were strongly up-regulated and were further investigated by ELISAs. Of these proteins, CXCL16 and TRANCE (RANKL) concentrations were analyzed in human serum samples. CXCL16 and TRANCE were increased in patients with pancreatic necrosis and abdominal infection. Receiver operated characteristics showed that CXCL16 was superior in predicting infected pancreatic necrosis when compared to C-reactive protein and TRANCE. CONCLUSIONS: Serum CXCL16 is increased in severe pancreatitis with infected pancreatic necrosis and identifies patients who benefit from surgical necrosectomy.

Simvastatin ameliorates renal lipidosis through the suppression of renal CXCL16 expression in mice with adriamycin-induced nephropathy.

AIMS: To investigate the roles of CXCL16 and ox-LDL in adriamycin (ADR)-induced nephropathy mice and to explore the mechanism of simvastatin on the renal protective effects of ADR nephropathy. METHODS: Fifteen male Balb/c mice were randomly divided into normal control (NC), ADR nephropathy and simvastatin-treated ADR nephropathy (ADR-SIM) groups. ADR nephropathy was induced by a single intravenous injection of ADR into the tail vein. All mice were sacrificed at the end of the 7th week, with the blood, 24-h urine and kidneys collected. The levels of ox-LDL and total cholesterol in the serum, the serum CXCL16, ox-LDL and NF-κB expression were detected. RESULTS: Compared with the NC group, the levels of serum total cholesterol and ox-LDL in the ADR and ADR-SIM groups were significantly higher, the level of serum albumin was significantly lower and the expression of CXCL16, ox-LDL and NF-κB in the renal tissue of ADR and ADR-SIM groups was significantly increased. Compared with the ADR group, the expressions of renal CXCL16, ox-LDL and NF-κB in the ADR-SIM group were significantly decreased. Levels of serum total cholesterol and ox-LDL were not significantly different between the two groups. CONCLUSIONS: Simvastatin exerts a protective effect on renal function and structure in mice with ADR nephropathy. The beneficial effects of simvastatin might be related to the decreasing expression of CXCL16 in glomerular podocytes followed by the decreasing endocytosis of ox-LDL in podocytes and inhibition of NF-κB pathway activation.

Chemokine receptor CXCR6-dependent hepatic NK T Cell accumulation promotes inflammation and liver fibrosis.

Chronic liver injury characteristically results in hepatic inflammation, which represents a prerequisite for organ fibrosis. Although NKT cells are abundantly present in liver and involved in hepatic inflammation, molecular mechanisms of their recruitment in liver fibrosis remained elusive. We hypothesized that chemokine receptor CXCR6 and its ligand CXCL16 control NKT cell migration and functionality in liver fibrosis. In patients with chronic liver diseases (n = 58), CXCR6 and CXCL16 expression was intrahepatically upregulated compared with controls. In murine liver, Cxcl16 was strongly expressed by endothelium and macrophages, whereas lymphocyte populations (NKT, NK, CD4 T, CD8 T cells) expressed CXCR6. Intravital two-photon microscopy imaging of Cxcr6(+/gfp) and Cxcr6(gfp/gfp) mice and chemotaxis studies in vitro revealed that CXCR6 specifically controls hepatic NKT cell accumulation during the early response upon experimental liver damage. Hepatic invariant NKT cells expressed distinct proinflammatory cytokines including IFN-γ and IL-4 upon injury. CXCR6-deficient mice were protected from liver fibrosis progression in two independent experimental models. Macrophage infiltration and protein levels of inflammatory cytokines IFN-γ, TNF-α, and IL-4 were also reduced in fibrotic livers of Cxcr6(-/-) mice, corroborating that hepatic NKT cells provide essential cytokine signals perpetuating hepatic inflammation and fibrogenesis. Adoptive transfer of NKT cells, but not CD4 T cells, isolated from wild type livers restored hepatic fibrosis in Cxcr6(-/-) mice upon experimental steatohepatitis. Our results demonstrate that hepatic NKT cells accumulate CXCR6-dependent early upon injury, thereby accentuating the inflammatory response in the liver and promoting hepatic fibrogenesis. Interfering with CXCR6/CXCL16 might therefore bear therapeutic potential in liver fibrosis.

Increased plasma CXCL16 levels in patients with chronic kidney diseases.

BACKGROUND: C-X-C chemokine ligand 16 (CXCL16) is a scavenger receptor for oxidized low-density lipoprotein that has been shown to promote atherogenic effects in vivo and to predict the long-term mortality in acute coronary syndrome. We conducted a cross-sectional study to test the hypothesis that elevated CXCL16 concentrations are associated with the change in renal function in patients with chronic kidney disease (CKD) at different stages of disease. MATERIALS AND METHODS: Two hundred and forty subjects including 200 patients with CKD (146 CKD from outpatients and 54 CKD with long-term haemodialysis) and 40 normal control subjects were recruited into this study. All CKD subjects underwent echocardiograms to assess left ventricular mass index. Plasma levels of CXCL16 and other relevant clinical and biochemical parameters in all subjects were obtained upon standard clinical examinations. RESULTS: Plasma CXCL16 levels were significantly increased with the development of CKD from early- and end-stage (P < 0·001 for trend) and significantly higher in CKD subjects than those of normal subjects (P<0·001). Furthermore, plasma CXCL16 levels in CKD patients with type 2 diabetes mellitus (DM) were higher than those of CKD patients without DM. Multiple stepwise regression analyses indicated that plasma CXCL16 levels were independently associated with estimated glomerular filtration rate, C-reactive protein and adiponectin (all P<0·05). CONCLUSIONS: Plasma CXCL16 levels are significantly increased with the development of early- to end-stage CKD and are independently associated with the change in renal function. Elucidating the role of CXCL16 as a biomarker or disease modifier in CKD progression requires further study.

Silencing of tissue factor by antisense deoxyoligonucleotide prevents monocrotaline/LPS renal injury in mice.

Tissue factor (TF) is involved in monocrotaline (MCT)/lipopolysaccharide (LPS) hepatotoxicity. It is not known whether MCT/LPS can cause renal toxicity and whether TF is involved in this toxicity. Thus, the present study was undertaken to investigate the potential renal toxicity after MCT/LPS co-treatment and the involvement of TF in this toxicity. MCT was delivered to ND4 male mice (200 mg/kg) per os followed 4 h later by treatment with LPS ip (6 mg/kg) to investigate its effect on kidney. We injected TF antisense oligonucleotide (TF-AS) intravenously (i.v) in mice prior to LPS treatment, to block TF, and measured their blood urea nitrogen (BUN), creatinine (CRE), alkaline phosphatase (ALP), and potassium. In MCT/LPS co-treated group, fibrin was detected on the glomerular capillary lumina, distal tubules of renal cortex, and the necrotic tubules of renal medulla. An elevation of BUN, creatinine, and the BUN/creatinine ratio was seen in mice with MCT/LPS co-treatment, compared to animals receiving LPS or MCT alone. Simultaneously, an aggressive tubular necrosis was seen in the medullary tubules in the same group which may account for the oliguria observed in these animals. Fourfold inductions in the plasma TF level was detected at 10 h after MCT/LPS co-treatment which increased to 18-fold at 24 h. Increased blood level of leptin, interleukin-6 (IL-6) and downregulation of tubular chemokine (C-X-C motif) ligand 16 (CXCL16) are characteristic features in MCT/LPS co-treated animal. On the other hand, mice injected with TF-AS in the presence of MCT/LPS co-treatment showed no elevation of the blood BUN, creatinine, potassium, and normal levels of the proinflammatory molecules. TF-AS injection significantly prevented glomerular and tubular fibrin deposition, tubular necrosis, and improvement of the animal survivability. Renal toxicity involving TF can be prevented successfully by the use of TF-AS.

Elevated expression of CXC chemokines in pediatric osteosarcoma patients.

BACKGROUND: Osteosarcoma is the most common malignant bone tumor in children. Despite the advent of chemotherapy, the survival of osteosarcoma patients has not been significantly improved recently. Chemokines are a group of signaling molecules that have been implicated in tumorigenesis and metastasis. METHODS: The authors used an antibody microarray to identify chemokines that were elevated in the plasma samples of osteosarcoma patients. The results were validated using enzyme-linked immunosorbent assays on an independent set of samples. The tumor expressions of 3 chemokines were examined in 2 sets of osteosarcoma tissue arrays. The authors also evaluated the proliferative effect of the chemokines in 4 osteosarcoma cell lines. RESULTS: The authors found that the plasma levels of CXCL4, CXCL6, and CXCL12 in the osteosarcoma patients were significantly higher than those in the controls, and the results were validated by an independent osteosarcoma cohort (P < .05). However, CXCL4 (100%) and CXCL6 (91%) were frequently expressed in osteosarcoma, whereas CXCL12 was only expressed in 4%. Survival analysis further showed that higher circulating levels of CXCL4 and CXCL6, but not CXCL12, were associated with a poorer outcome of osteosarcoma patients. Addition of exogenous chemokines significantly promoted the growth of different osteosarcoma cells (P < .05). CONCLUSIONS: The results demonstrate that CXCL4 and CXCL6 are frequently expressed in osteosarcoma, and that the plasma levels of these 2 chemokines are associated with patient outcomes. Further study of these circulating chemokines may provide a promising approach for prognostication of osteosarcoma. Targeting these chemokines or their receptors may also lead to a novel therapeutic invention.

Overexpression of CXCL16 promotes a vulnerable plaque phenotype in Apolipoprotein E-Knockout Mice.

BACKGROUND: CXCL16 has been shown to be involved in atherosclerotic lesion development, but its role in preexisting lesions is still unclear. This study aims to assess the effect of CXCL16 on the stability of preexisting lesions. METHODS: We firstly measured plasma CXCL16 level in Apolipoprotein E-Knockout (ApoE KO) mice with either high-cholesterol diet (HCD) or normal diet (ND) by enzyme-linked immunosorbent assay (ELISA). Then, silastic collars were placed around the carotid arteries in HCD-ApoE KO mice to accelerate atherosclerotic lesions. Five weeks later, CXCL16 was overexpressed by intravenous injection of lentivirus carrying CXCL16 transgene. Two weeks after infection, lesions were stained with hematoxylin and eosin (HE) and with oil red O. Biomarkers in the lesions, such as MMPs, CCL2, VCAM-1 and TNF-α were measured by real-time polymerase chain reaction (RT-PCR), which indicate the instability of plaques. RESULTS: The level of CXCL16 in plasma was higher in HCD-ApoE KO mice as compared to ND-ApoE KO mice. Circulating CXCL16 overexpression does not affect the size of preexisting plaques, but it leads to vulnerable plaque morphology and increases the expression of markers of plaque destabilization. CONCLUSION: Systemic CXCL16 becomes much higher in atherosclerosis, and it could be a potential atherogenic biomarker. Overexpression of CXCL16 promotes the evolution of preexisting lesions to vulnerable plaques in ApoE KO mice.

Expression and regulation of the chemokine CXCL16 in Crohn's disease and models of intestinal inflammation.

BACKGROUND: CXCL16 mediates adhesion and phagocytosis of both Gram-negative and Gram-positive bacteria and is a strong chemoattractant for CXCR6+ T cells. In this study, we determined the so far unknown expression and signal transduction of the novel CXCL16-CXCR6 chemokine-ligand receptor system in intestinal inflammation in vivo and in vitro. METHODS: CXCL16 mRNA was measured by quantitative PCR in human colonic biopsies of patients with Crohn's disease (CD) as well as in the TNFΔARE mouse model of ileitis and in murine cytomegalovirus (MCMV)-induced colitis. CXCL16 serum levels were analyzed by ELISA. CXCL16-induced signal transduction was analyzed in intestinal epithelial cells with phospho-specific antibodies for mitogen-activated protein (MAP) kinases and Akt. RESULTS: We found an inverse expression pattern of CXCL16 and CXCR6, with highest CXCL16 mRNA expression in the proximal murine small intestine and the highest CXCR6 mRNA expression in the distal colon. CXCL16 and CXCR6 mRNA were expressed in colorectal cancer (CRC)-derived intestinal epithelial cell (IEC) lines. CRC-expressed CXCR6 was functional, as demonstrated by CXCL16-induced MAP kinase and Akt activation. Intestinal CXCL16 expression was elevated in the TNFΔARE mouse model of ileitis and in MCMV-induced colitis (P < 0.05) and in the sera and colons of patients with CD (P < 0.05), where its expression correlated highly with CXCR6 and IL-8 levels (r = 0.85 and 0.89, respectively). CONCLUSIONS: CRC-derived IECs express the functional CXCL16 receptor CXCR6. CXCL16 mRNA and protein expression is up-regulated in intestinal inflammation in vitro and in CD patients, suggesting an important role for this chemokine in intestinal inflammation.

Expression of bovine granulocyte chemotactic protein-2 (GCP-2) in neutrophils and a mammary epithelial cell line (MAC-T) in response to various bacterial cell wall components.

CXC chemokines are potential attractants for polymorphonuclear leucocytes (PMNs) and play an important role in resistance to infectious diseases, such as bovine mastitis. In this study, a bovine mammary epithelial cell line (MAC-T) and blood PMNs were stimulated with bacterial cell wall components of gram negative and gram positive bacteria, including lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN). The expression of two CXC chemokines, interleukin (IL)-8 and granulocyte chemotactic protein (GCP)-2 was analysed by real-time PCR. High concentrations (1 or 10 µg/mL) of LPS and LTA, but not PGN, significantly increased the expression of GCP-2 and IL-8 in both MAC-T and PMNs. Biopsies from mammary glands of cattle with clinical Escherichia coli mastitis also had increased expression of GCP-2. Using an in vitro transepithelial migration assay, recombinant human GCP-2 (rhGCP-2) showed weak chemoattractant effects on bovine blood PMNs. It was concluded that PMNs and MAC-T cells can express GCP-2 in response to certain bacterial cell components during the course of mastitis.

Neutrophil chemokines GCP-2 and GRO-alpha in patients with inflammatory bowel disease.

OBJECTIVE: To measure the serum levels of neutrophils chemokine granulocyte chemotactic protein-2 (GCP-2) and interleukin-8 (IL-8) in Crohn's disease (CD) and ulcerative colitis (UC) patients and compare them with serum levels of growth-related oncogene (GRO-alpha). METHODS: Forty-two patients with inflammatory bowel disease (24 CD and 18 UC) and 38 matched healthy subjects were recruited. Their serum GCP-2, IL-8 and GRO-alpha were measured by a specific enzyme immunoassay kit. RESULTS: The serum levels of GCP-2 were significantly higher in the CD than the UC patients but lower than in the healthy subjects. The GCP-2 in the UC patients were significantly lower than in the healthy subjects. The GRO-alpha levels were significantly higher in the IBD patients than in the healthy subjects. The IL-8 levels were under the detectable limit in both the IBD and the healthy subjects. CONCLUSION: In this group of patients, GCP-2 did not participate in the inflammatory response in IBD. GRO-alpha could be an important factor that enhances the inflammatory state in IBD.

Elevated urinary VCAM-1, P-selectin, soluble TNF receptor-1, and CXC chemokine ligand 16 in multiple murine lupus strains and human lupus nephritis.

In an effort to identify potential biomarkers in lupus nephritis, urine from mice with spontaneous lupus nephritis was screened for the presence of VCAM-1, P-selectin, TNFR-1, and CXCL16, four molecules that had previously been shown to be elevated in experimental immune nephritis, particularly at the peak of disease. Interestingly, all four molecules were elevated approximately 2- to 4-fold in the urine of several strains of mice with spontaneous lupus nephritis, including the MRL/lpr, NZM2410, and B6.Sle1.lpr strains, correlating well with proteinuria. VCAM-1, P-selectin, TNFR-1, and CXCL16 were enriched in the urine compared with the serum particularly in active disease, and were shown to be expressed within the diseased kidneys. Finally, all four molecules were also elevated in the urine of patients with lupus nephritis, correlating well with urine protein levels and systemic lupus erythematosus disease activity index scores. In particular, urinary VCAM-1 and CXCL16 showed superior specificity and sensitivity in distinguishing subjects with active renal disease from the other systemic lupus erythematosus patients. These studies uncover VCAM-1, P-selectin, TNFR-1, and CXCL16 as a quartet of molecules that may have potential diagnostic significance in lupus nephritis. Longitudinal studies are warranted to establish the clinical use of these potential biomarkers.

Lipid peroxides, superoxide dismutase and circulating IL-8 and GCP-2 in patients with severe obstructive sleep apnea: a pilot study.

Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity and mortality and many other physiological and immunological disorders. An increase in hypoxia due to OSA may cause generation of reactive oxygen species (ROS). ROS are toxic to biomembranes and may lead to peroxidation of lipids. An increase in systemic biomarkers of inflammation and oxidative stress has been found in patients with OSA. The first aim of this study was to test the hypothesis that OSA is linked to increased oxidative stress (lipid peroxidation) and decreased antioxidant defense [superoxide dismutase (SOD)]. The second aim was to measure the serum levels of neutrophil chemokines [interleukin-8 (IL-8)], and granulocyte chemotactic protein-2 (GCP-2) in OSA patients. Twenty five patients with severe OSA and 17 healthy subjects were recruited. IL-8 and GCP-2 were measured in the serum by a specific enzyme immunoassay kit. Oxidative stress level was quantitated by measurement of thiobarbituric acid reactive substances. SOD enzymatic activity was measured by purely chemical system based on NAD(P)H oxidation. Mean SOD and lipid peroxidation concentrations of patients were not significantly different from those of control subjects (0.29+/-0.015 vs 0.31+/-0.01 U/ml and 4.64+/-0.57 vs 4.62+/-0.54 mmol/ml, respectively). Higher concentrations of IL-8 and GCP-2 were found in OSA patients (198.8+/-4.76 vs 180.83+/-3.38 and 383.34+/-46.19 vs 218+/-13.16 pg/ml, respectively, p<0.005). The present study does not support the hypothesis that OSA is linked to increased oxidative stress and decreased antioxidant defense. On the other hand, it suggests that systemic inflammation characterizes OSA patients.