Interferon-inducible protein-10 involves vascular smooth muscle cell migration, proliferation, and inflammatory response

Down syndrome and postoperative hemodynamics in patients undergoing surgery for congenital cardiac communications

Although Down syndrome (DS) is considered a risk factor for hemodynamic instabilities (mainly pulmonary hypertension-PH) following surgery for congenital cardiac communications, many DS patients do surprising well postoperatively. We prospectively analyzed perioperative factors for a possible correlation with post-cardiopulmonary bypass (CPB) inflammatory reaction and postoperative PH in pediatric subjects. Sixty patients were enrolled (age 3 to 35 months), 39 of them with DS. Clinical and echocardiographic parameters (anatomical and hemodynamic) were computed preoperatively. Pulmonary and systemic mean arterial pressures (PAP and SAP) were assessed invasively intra and postoperatively. Immediate postoperative PAP/SAP ratio (PAP/SAPIPO) and the behavior of pressure curves were selected as primary outcome. Serum levels of 36 inflammatory proteins were measured by chemiluminescence preoperatively and 4 h post CPB. Of all factors analyzed, peripheral oxygen saturation (O2Sat, bedside assessment) was the only preoperative predictor of PAP/SAPIPO at multivariate analysis (p = 0.007). Respective values in non-DS, DS/O2Sat ≥ 95% and DS/O2Sat < 95% subgroups were 0.34 (0.017), 0.40 (0.027) and 0.45 (0.026), mean (SE), p = 0.004. The difference between non-DS and DS groups regarding postoperative PAP curves (upward shift in DS patients, p = 0.015) became nonsignificant (p = 0.114) after adjustment for preoperative O2Sat. Post-CPB levels of at least 5 cytokines were higher in patients with O2Sat < 95% versus those at or above this level, even within the DS group (p < 0.05). Thus, a baseline O2Sat < 95% representing pathophysiological phenomena in the airways and the distal lung, rather than DS in a broad sense, seems to be associated with post-CPB inflammation and postoperative PH in these patients.

CXCL10 May Be Responsible for Susceptibility to Pulmonary Embolism in COVID-19 Patients

Background

Although the potential of coronavirus disease 2019 (COVID-19) patients to develop pulmonary embolism (PE) is widely recognized, the underlying mechanism has not been completely elucidated. This study aimed to identify genes common to COVID-19 and PE to reveal the underlying pathogenesis of susceptibility to PE in COVID-19 patients.

Methods

COVID-19 genes were obtained from the GEO database and the OMIM, CTD, GeneCards, and DisGeNET databases; PE genes were obtained from the OMIM, CTD, GeneCards, and DisGeNET databases. We overlapped the genes of COVID-19 and PE to obtain common genes for additional analysis, including functional enrichment, protein-protein interaction, and immune infiltration analysis. Hub genes were identified using cytoHubba, a plugin of Cytoscape, and validated using the independent datasets GSE167000 and GSE13535. The genes validated by the above datasets were further validated in clinical samples.

Results

We obtained 36 genes shared by PE and COVID-19. Functional enrichment and immune infiltration analyses revealed the involvement of cytokines and immune activation. Five genes (CCL2, CXCL10, ALB, EGF, and MKI67) were identified as hub genes common to COVID-19 and PE. CXCL10 was validated in both independent datasets (GSE167000 and GSE13535). Serum levels of CXCL10 in the COVID-19 group and the COVID-19 combined with PE group were significantly higher than those in the healthy control group (P<0.001). In addition, there were significant differences between the COVID-19 group and the COVID-19 combined with PE group (P<0.01).

Conclusion

Our study reveals common genes shared by PE and COVID-19 and identifies CXCL10 as a possible cause of susceptibility to PE in COVID-19 patients.

Respiratory viruses and postoperative hemodynamics in patients with unrestrictive congenital cardiac communications: a prospective cohort study

BACKGROUND

Pulmonary vascular abnormalities pose a risk for severe life-threatening hemodynamic disturbances following surgical repair of congenital cardiac communications (CCCs). In the distal lung, small airways and vessels share a common microenvironment, where biological crosstalks take place. Because respiratory cells infected by viruses express a number of molecules with potential impact on airway and vascular remodeling, we decided to test the hypothesis that CCC patients carrying viral genomes in the airways might be at a higher risk for pulmonary (and systemic) hemodynamic disturbances postoperatively.

METHODS

Sixty patients were prospectively enrolled (age 11 [7-16] months, median with interquartile range). Preoperative pulmonary/systemic mean arterial pressure ratio (PAP/SAP) was 0.78 (0.63-0.88). The presence or absence of genetic material for respiratory viruses in nasopharyngeal and tracheal aspirates was investigated preoperatively in the absence of respiratory symptoms using real-time polymerase chain reaction (kit for detection of 19 pathogens). Post-cardiopulmonary bypass (CPB) inflammatory reaction was analyzed by measuring serum levels of 36 inflammatory proteins (immunoblotting) 4 h after its termination. Postoperative hemodynamics was assessed using continuous recording of PAP and SAP with calculation of PAP/SAP ratio.

RESULTS

Viral genomes were detected in nasopharynx and the trachea in 64% and 38% of patients, respectively. Rhinovirus was the most prevalent agent. The presence of viral genomes in the trachea was associated with an upward shift of postoperative PAP curve (p = 0.011) with a PAP/SAP of 0.44 (0.36-0.50) in patients who were positive versus 0.34 (0.30-0.45) in those who were negative (p = 0.008). The presence or absence of viral genomes in nasopharynx did not help predict postoperative hemodynamics. Postoperative PAP/SAP was positively correlated with post-CPB levels of interleukin-1 receptor antagonist (p = 0.026), macrophage migration inhibitory factor (p = 0.019) and monocyte chemoattractant protein-1 (p = 0.031), particularly in patients with virus-positive tracheal aspirates.

CONCLUSIONS

Patients with CCCs carrying respiratory viral genomes in lower airways are at a higher risk for postoperative pulmonary hypertension, thus deserving special attention and care. Preoperative exposure to respiratory viruses and post-CPB inflammatory reaction seem to play a combined role in determining the postoperative behavior of the pulmonary circulation.

​Circulating Cytokines in Myocardial Infarction Are Associated With Coronary Blood Flow

Background

The level of systemic inflammation correlates with the severity of the clinical course of acute myocardial infarction (AMI). It has been shown that circulating cytokines and endothelial dysfunction play an important role in the process of clot formation. The aim of our study was to assess the concentration of various circulating cytokines, endothelial function and blood clotting in AMI patients depending on the blood flow through the infarction-related artery (IRA).

Methods

We included 75 patients with AMI. 58 presented with ST-elevation myocardial infarction (STEMI) and 17 had non-ST-elevation myocardial infarction (non-STEMI). A flow-mediated dilation test (FMD test), thrombodynamics and rotational thromboelastometry as well as assessment of 14 serum cytokines using xMAP technology were performed.

Findings

Non-STEMI-patients were characterized by higher levels of MDC, MIP-1β, TNF-α. Moreover, we observed that patients with impaired blood flow through the IRA (TIMI flow 0-1) had higher average and initial clot growth rates, earlier onset of spontaneous clots, C-reactive protein (CRP) and IL-10 compared to patients with preserved blood flow through the IRA (TIMI flow 2-3). Patients with TIMI 2-3 blood flow had higher level of IP-10. IL-10 correlated with CRP and pro-inflammatory cytokines levels, initial clot growth rate and clot lysis time in TIMI 0-1 patients. All these differences were statistically significant.

Interpretation

We demonstrated that concentrations of the inflammatory cytokines correlate not only with the form of myocardial infarction (STEMI or non-STEMI), but also with the blood flow through the infarct-related artery. Inflammatory response, functional state of endothelium, and clot formation are closely linked with each other. A combination of these parameters affects the patency of the infarct-related artery.

HnRNPK and lysine specific histone demethylase-1 regulates IP-10 mRNA stability in monocytes

Altered mRNA metabolism is a feature of many inflammatory diseases. Post transcriptional regulation of interferon-γ-inducible protein (IP)-10 has been uncharacterized in diabetes conditions. RNA-affinity capture method and RNA immuno-precipitation revealed S100b treatment increased the binding of heterogeneous nuclear ribonucleoprotein (hnRNP)K to the IP-10 3'UTR and increased IP-10 mRNA accumulation. Luciferase activity assay using reporter plasmids showed involvement of IP-10 3'UTR. Knocking down of hnRNPK destabilized S100b induced IP-10 mRNA accumulation. S100b promoted the translocation of hnRNPK from nucleus to the cytoplasm and this was confirmed by phosphomimetic S284/353D mutant and non-phosphatable S284/353A hnRNPK mutant. S100b treatment demethylates hnRNPK at Lys219 by Lysine Specific Demethylase (LSD)-1. HnRNPK^K219I, a demethylation defective mutant increased IP-10 mRNA stability. Apparently, triple mutant hnRNPK^{K219I/S284D/353D} promoted IP-10 mRNA stability. Interestingly, knocking down LSD-1 abolished S100b induced IP-10 mRNA accumulation. These observations show for the first time that IP-10 mRNA stability is dynamically regulated by Lysine demethylation of hnRNPK by LSD-1. These results indicate that hnRNPK plays an important role in IP-10 mRNA stability induced by S100b which could exacerbate monocyte activation, relevant to the pathogenesis of diabetic complications like atherosclerosis.

The Involvement of CXC Motif Chemokine Ligand 10 (CXCL10) and Its Related Chemokines in the Pathogenesis of Coronary Artery Disease and in the COVID-19 Vaccination: A Narrative Review

Coronary artery disease (CAD) and coronary heart disease (CHD) constitute two of the leading causes of death in Europe, USA and the rest of the world. According to the latest reports of the Iranian National Health Ministry, CAD is the main cause of death in Iranian patients with an age over 35 years despite a significant reduction in mortality due to early interventional treatments in the context of an acute coronary syndrome (ACS). Inflammation plays a fundamental role in coronary atherogenesis, atherosclerotic plaque formation, acute coronary thrombosis and CAD establishment. Chemokines are well-recognized mediators of inflammation involved in several bio-functions such as leucocyte migration in response to inflammatory signals and oxidative vascular injury. Different chemokines serve as chemo-attractants for a wide variety of cell types including immune cells. CXC motif chemokine ligand 10 (CXCL10), also known as interferon gamma-induced protein 10 (IP-10/CXLC10), is a chemokine with inflammatory features whereas CXC chemokine receptor 3 (CXCR3) serves as a shared receptor for CXCL9, 10 and 11. These chemokines mediate immune responses through the activation and recruitment of leukocytes, eosinophils, monocytes and natural killer (NK) cells. CXCL10, interleukin (IL-15) and interferon (IFN-g) are increased after a COVID-19 vaccination with a BNT162b2 mRNA (Pfizer/BioNTech) vaccine and are enriched by tumor necrosis factor alpha (TNF-α) and IL-6 after the second vaccination. The aim of the present study is the presentation of the elucidation of the crucial role of CXCL10 in the patho-physiology and pathogenesis of CAD and in identifying markers associated with the vaccination resulting in antibody development.

Role of inflammatory chemokines in hypertension

Hypertension is associated with immune cells activation and their migration into the kidney, vasculature, heart and brain. These inflammatory mechanisms are critical for blood pressure regulation and mediate target organ damage, creating unique novel targets for pharmacological modulation. In response to angiotensin II and other pro-hypertensive stimuli, the expression of several inflammatory chemokines and their receptors is increased in the target organs, mediating homing of immune cells. In this review, we summarize the contribution of key inflammatory chemokines and their receptors to increased accumulation of immune cells in target organs and effects on vascular dysfunction, remodeling, oxidative stress and fibrosis, all of which contribute to blood pressure elevation. In particular, the role of CCL2, CCL5, CXCL8, CXCL9, CXCL10, CXCL11, CXCL16, CXCL1, CX3CL1, XCL1 and their receptors in the context of hypertension is discussed. Recent studies have tested the efficacy of pharmacological or genetic targeting of chemokines and their receptors on the development of hypertension. Promising results indicate that some of these pathways may serve as future therapeutic targets to improve blood pressure control and prevent target organ consequences including kidney failure, heart failure, atherosclerosis or cognitive impairment.

Platelet proteome changes in dogs with congestive heart failure

BACKGROUND

Platelets play a central role in the development of cardiovascular diseases and changes in their proteins are involved in the pathophysiology of heart diseases in humans. There is lack of knowledge about the possible role of platelets in congestive heart failure (CHF) in dogs. Thus, this study aimed to investigate the changes in global platelet proteomes in dogs with CHF, to clarify the possible role of platelets in the physiopathology of this disease. Healthy-dogs (n = 10) and dogs with acute CHF due to myxomatous mitral valve disease (MMVD, n = 10) were used. Acute CHF was defined based on the clinical (increased respiratory rate or difficulty breathing) and radiographic findings of pulmonary edema. Dogs Blood samples were collected into tubes with acid-citrate-dextrose, and platelet-pellets were obtained by centrifuge and washing steps. Platelet-proteomes were identified using LC-MS based label-free differential proteome expression analysis method and matched according to protein database for Canis lupus familiaris.

RESULTS

Totally 104 different proteins were identified in the platelets of the dogs being 4 out of them were significantly up-regulated and 6 down-regulated in acute CHF dogs. Guanine-nucleotide-binding protein, apolipoproteins (A-II and C-III) and clusterin levels increased, but CXC-motif-chemokine-10, cytochrome-C-oxidase-subunit-2, cathepsin-D, serine/threonine-protein-phosphatase-PP1-gamma-catalytic-subunit, creatine-kinase-B-type and myotrophin levels decreased in acute CHF dogs. These proteins are associated with several molecular functions, biological processes, signaling systems and immune-inflammatory responses.

CONCLUSION

This study describes by first time the changes in the protein composition in platelets of dogs with acute CHF due to MMVD. Our findings provide a resource for increase the knowledge about the proteome of canine platelets and their roles in CHF caused by MMVD and could be a tool for further investigations about the prevention and treatment of this disease.

Evaluation of IP10 and miRNA 296-a Expression Levels in Peripheral Blood Mononuclear Cell of Coronary Artery Disease Patients and Controls

Coronary artery disease (CAD) is the main cause of death worldwide. Atherosclerosis, the leading underlying cause of CAD, is a progressive inflammatory disease. miRNAs play a substantial role in inflammation. The aim of this study was to investigate the associations of peripheral blood mononuclear cells (PBMCs) gene expression of IP10 and miRNA 296-a and serum levels of IP10 and serum inflammatory cytokines interleukin-6 (IL-6) in CAD patients and controls. This is a case-control study conducted on 82 angiography confirmed CAD patients and 82 controls. PBMC expressions of miR-296a and IP10 were evaluated by real-time method, and serum concentrations of IL-6 and TNF-α were evaluated by enzyme-linked immunosorbent assay in the study population. A significant increase was found for serum IP10, IL-6, and TNF-α levels, and PBMC expression of IP10 and miRNA 296-a genes expression of CAD as comparison with controls. No significant correlation was found between IP10 gene expression and miRNA 296-a. A significant positive correlation was found between PBMC gene expression level of IP10 and serum concentrations of IP10 and cytokines IL-6 and TNF-α levels. Taking together, in PBMC of CAD patients, the IP10 and 296-a miRNA genes expression levels were increased significantly than controls. IP10, IL-6, and TNF-α levels in CAD patients were more than those in controls significantly. Concerning positive relationship between miRNA 296-a gene expression level and serum concentrations of IL-6 and TNF-α in CAD patients, it is proposed that IL-6 and TNF-α inhibitor could be the main targets of miRNA 296a and, thereby the IL-6 and TNF-α levels were increased; however, further study is needed.

A Pro-Inflammatory Biomarker-Profile Predicts Amputation-Free Survival in Patients with Severe Limb Ischemia

Patients with Severe Limb Ischemia (SLI) have a high risk of amputation and mortality. Here, we investigated a panel of serum biomarkers with the aim of identifying biomarkers for major events and mechanisms that contribute to disease progression in established SLI. A panel of biomarkers including GROα, HGF, SCF, SCGFβ, SDF1α, TRAIL, IL-6, IL-8, FGFβ, GCSF, GMCSF, IP10, MCP1, PDGFbb, RANTES, TNFα, VEGF, sICAM, sVCAM, TM, and E-selectin was measured in serum samples from a subset (n = 108) of the JUVENTAS cohort. The primary outcome was major events, defined as major amputation or death. The inflammatory biomarkers IL-6, IL-8, GROα and IP-10 were significantly elevated in patients who reached a major endpoint. Results were validated in a secondary cohort (n = 146). Cox regression showed that adjusted hazard ratios were 1.40 (95% CI: 1.15-1.70, p = 0.0007) and 1.48 (95% CI 1.16-1.87, p = 0.001) for IL-6 and IP-10 in a fully adjusted model containing both biomarkers. A prediction model using IL-6 and IP-10 showed predictive accuracy with an AUC of ~ 78% in both discovery and validation cohorts, which is higher than previously published models. We conclude that inflammatory biomarkers predict major events in patients with SLI and allow the creation of biomarker-based risk-prediction models.

Cardiovascular endothelial inflammation by chronic coexposure to lead (Pb) and polycyclic aromatic hydrocarbons from preschool children in an e-waste recycling area

Lead (Pb) and polycyclic aromatic hydrocarbon (PAH) exposure is positively associated with cardiovascular disease (CVD), and the possible potential mechanism may be caused by damage to the endothelium by modulation of inflammatory processes. No comprehensive research shows co-exposure of Pb and PAH on cardiovascular endothelial inflammation in electronic waste (e-waste) exposed populations. Given this, the aim of this study is to provide evidence for a relationship between Pb and PAH co-exposure and cardiovascular endothelial inflammation, in an e-waste-exposed population, to delineate the link between a potential mechanism for CVD and environmental exposure. We recruited 203 preschool children (3-7 years) were enrolled from Guiyu (e-waste-exposed group, n = 105) and Haojiang (reference group, n = 98). Blood Pb levels and urinary PAH metabolites were measured. Percentages of T cells, CD4⁺ T cells and CD8⁺ T cells, complete blood counts, endothelial inflammation biomarker (serum S100A8/A9), and other inflammatory biomarkers [serum interleukin (IL)-6, IL-12p70, gamma interferon-inducible protein 10 (IP-10)] levels were evaluated. Blood Pb, total urinary hydroxylated PAH (ΣOHPAH), total hydroxynaphthalene (ΣOHNap) and total hydroxyfluorene (ΣOHFlu) levels, S100A8/A9, IL-6, IL-12p70 and IP-10 concentrations, absolute counts of monocytes, neutrophils, and leukocytes, as well as CD4⁺ T cell percentages were significantly higher in exposed children. Elevated blood Pb, urinary 2-hydroxynaphthalene (2-OHNap) and ΣOHFlu levels were associated with higher levels of IL-6, IL-12p70, IP-10, CD4⁺ T cell percentages, neutrophil and monocyte counts. Mediator models indicated that neutrophils exert the significant mediation effect on the relationship between blood Pb levels and S100A8/A9. IL-6 exerts a significant mediation effect on the relationship between blood Pb levels and IP-10, as well as the relationship between urinary ΣOHFlu levels and IP-10. Our results indicate that children with elevated exposure levels of Pb and PAHs have exacerbated vascular endothelial inflammation, which may indicate future CVD risk in e-waste recycling areas.

Microbiota control acute arterial inflammation and neointimal hyperplasia development after arterial injury

BACKGROUND

The microbiome has a functional role in a number of inflammatory processes and disease states. While neointimal hyperplasia development has been linked to inflammation, a direct role of the microbiota in neointimal hyperplasia has not yet been established. Germ-free (GF) mice are an invaluable model for studying causative links between commensal organisms and the host. We hypothesized that GF mice would exhibit altered neointimal hyperplasia following carotid ligation compared to conventionally raised (CONV-R) mice.

METHODS

Twenty-week-old male C57BL/6 GF mice underwent left carotid ligation under sterile conditions. Maintenance of sterility was assessed by cultivation and 16S rRNA qPCR of stool. Neointimal hyperplasia was assessed by morphometric and histologic analysis of arterial sections after 28 days. Local arterial cell proliferation and inflammation was assessed by immunofluorescence for Ki67 and inflammatory cell markers at five days. Systemic inflammation was assessed by multiplex immunoassays of serum. CONV-R mice treated in the same manner served as the control cohort. GF and CONV-R mice were compared using standard statistical methods.

RESULTS

All GF mice remained sterile during the entire study period. Twenty-eight days after carotid ligation, CONV-R mice had significantly more neointimal hyperplasia development compared to GF mice, as assessed by intima area, media area, intima+media area, and intima area/(intima+media) area. The collagen content of the neointimal lesions appeared qualitatively similar on Masson's trichrome staining. There was significantly reduced Ki67 immunoreactivity in the media and adventitia of GF carotid arteries 5 days after ligation. GF mice also had increased arterial infiltration of anti-inflammatory M2 macrophages compared to CONV-R mouse arteries and a reduced proportion of mature neutrophils. GF mice had significantly reduced serum IFN-γ-inducible protein (IP)-10 and MIP-2 5 days after carotid ligation, suggesting a reduced systemic inflammatory response.

CONCLUSIONS

GF mice have attenuated neointimal hyperplasia development compared to CONV-R mice, which is likely related to altered kinetics of wound healing and acute inflammation. Recognizing the role of commensals in the regulation of arterial remodeling will provide a deeper understanding of the pathophysiology of restenosis and support strategies to treat or reduce restenosis risk by manipulating microbiota.

trans-Lycopene from tomato juice attenuates inflammatory biomarkers in human plasma samples: An intervention trial

SCOPE

The effect of carotenoids from tomato juice (TJ) on inflammatory biomarkers was evaluated by performing a 4-week dose-response nutritional trial in a population at high cardiovascular risk.

METHODS AND RESULTS

An open, prospective, randomized, cross-over, and controlled clinical trial was carried out with 28 volunteers (mean age 69.7 ± 3.1 years; mean BMI 31.5 ± 3.6 kg/m² ) at high cardiovascular risk, which were assigned to consume daily for 4 weeks in random order: 200 mL (LD) or 400 mL (HD) of TJ, or water as a control (C), with a 21-day wash-out period between each intervention. Blood samples were collected at baseline (B) and after each intervention. Endpoints included significant changes in plasmatic carotenoids, and adhesion molecules ICAM-1, and VCAM-1, as well as a tendency to decrease the chemokine IL-8. Compared to C, concentration of ICAM-1, and VCAM-1 were significantly lower (p ˂ 0.001), after each TJ intervention. Decreases were correlated remarkably with the trans-lycopene, while the other carotenoids present in TJ have presented a minor association or no association with changes in these molecules.

CONCLUSION

trans-Lycopene from TJ may attenuate the risk of cardiovascular disease by reducing the concentration of important inflammatory molecules related to atherosclerosis.

IP-10/CXCR3 Axis Promotes the Proliferation of Vascular Smooth Muscle Cells through ERK1/2/CREB Signaling Pathway

Excessive proliferation of vascular smooth muscle cells is one of the main pathological processes leading to atherosclerosis and intimal hyperplasia after vascular interventional therapy. Our previous study has shown that interferon-γ inducible protein-10 contributes to the proliferation of vascular smooth muscle cell. However, the underlying mechanisms remain unclear. Extracellular signal-regulated kinase 1/2, serine/threonine kinase Akt, and cAMP response element binding protein are signaling pathways, which are considered to play important roles in the processes of vascular smooth muscle cell proliferation. Moreover, chemokine receptor 3 and Toll-like receptor 4 are potential receptors of inducible protein-10 in this process. In the present study, IP-10 was found to directly induce vascular smooth muscle cell proliferation, and exposure to inducible protein-10 activated extracellular signal-regulated kinase 1/2, serine/threonine kinase, and cAMP response element binding protein signaling. Inhibitor of extracellular signal-regulated kinase 1/2, rather than inhibitor of serine/threonine kinase, inhibited the phosphorylation of cAMP response element binding protein and reduced inducible protein-10-stimulated vascular smooth muscle cell proliferation. Knockdown of cAMP response element binding protein by siRNA inhibited inducible protein-10-induced vascular smooth muscle cell proliferation. Moreover, anti-CXCR3 IgG, instead of anti-Toll-like receptor 4 IgG, reduced inducible protein-10-induced vascular smooth muscle cell proliferation and inducible protein-10-stimulated extracellular signal-regulated kinase 1/2 and cAMP response element binding protein activation. Together, these results indicate that inducible protein-10 promotes vascular smooth muscle cell proliferation via chemokine receptor 3 and activation of extracellular signal-regulated kinase 1/2 inducible protein-10-induced vascular smooth muscle cell proliferation. These data provide important targets for future studies to modulate atherosclerosis and restenosis after vascular interventional therapy.

C-X-C motif chemokine 10 in non-alcoholic steatohepatitis: role as a pro-inflammatory factor and clinical implication

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. Non-alcoholic steatohepatitis (NASH) is a more severe form of NAFLD and causes subsequent pathological changes including cirrhosis and hepatocellular carcinoma. Inflammation is the key pathological change in NASH and involves a series of cytokines and chemokines. The C-X-C motif chemokine 10 (CXCL10), which is known as a pro-inflammation chemokine, was recently proven to play a pivotal role in the pathogenesis of NASH. Hepatic CXCL10 is mainly secreted by hepatocytes and liver sinusoidal endothelium. By binding to its specific receptor CXCR3, CXCL10 recruits activated CXCR3+ T lymphocytes and macrophages to parenchyma and promotes inflammation, apoptosis and fibrosis. The circulating CXCL10 level correlates with the severity of lobular inflammation and is an independent risk factor for NASH patients. Thus, CXCL10 may be both a potential prognostic tool and a therapeutic target for the treatment of patients with NASH. The aim of this review is to highlight the growing advances in basic knowledge and clinical interest of CXCL10 in NASH to propagate new insights into novel pharmacotherapeutic avenues.

Interferon-γ, interleukin-10 and interferon-inducible protein 10 (CXCL10) as serum biomarkers for the early allograft dysfunction after liver transplantation

Orthotopic liver transplantation (LTP) is nowadays a standard procedure, and provides the chance of survival of patients with end-stage non-treatable chronic liver disease or acute liver failure. Despite long-term survival with a good quality of life in the majority of patients, about 20% develop early allograft dysfunction (EAD), which leads to death or the need for re-transplantation. Therefore, the early diagnosis of EAD and evaluation of its risk factors are very important. Many primary pathological processes leading to EAD are accompanied by the release of different mediators and by a change of biochemical parameters detectable in the peripheral blood. The aim of this study was to investigate cytokines as well as soluble mediators in the serum of patients with and without EAD from our LTP bank, and to evaluate their predictive and prognostic values for EAD. We demonstrated for the first time that the level of IFNγ during the nearest preoperative period may serve as a predictive parameter for EAD. We additionally found that IL-10 and CXCL10 (IP-10) levels in the early postoperative period can be prognostic for EAD. We believe our data expand the spectrum of predictive and prognostic parameters for EAD in LTP.

Differential regulation of pericyte function by the CXC receptor 3

Pericytes are mural cell that have been found to play important roles in promoting blood vessel development and regulating blood flow. The signals that attract pericytes to maturing vessels during the resolution phase of wound healing are unknown. In this study, we examine the role of the chemokine receptor CXC receptor 3 (CXCR3) ligands, as they are produced by maturing endothelial cells. Pericytes isolated from muscle and retina were found to by and large only express the B-isoform of CXCR3 (CXCR3B), with expression being independent of the mitotic state of the cells. Pericyte stimulation with the CXCR3 ligands Mig (CXCL9), IP-9/I-TAC (CXCL11), or IP-10 (CXCL10) resulted in the activation of ERK but not AKT. Treatment with Mig or IP-9, but not IP-10, enhanced p38(MAPK) phosphorylation. Interestingly, while cyclic adenosine monophosphate is generated downstream of CXCR3B in other cells, protein kinase A activation was not observed in these pericytes when treated with these three CXCR3 ligands. The increase in ERK activity resulted in a slight increase in cell transmigration, with the inhibition of ERK leading to a decrease in CXCR3B mediated migration and inhibition of p38(MAPK) reducing transmigration through small pores. These ligands did not affect proliferation. These data are the first to characterize CXCR3B as the predominant isoform expressed on pericytes, and was found on these diverse cells isolated from both muscle and eye. We also show that CXCR3B signaling stimulates transmigration of barrier pores in pericytes as opposed to its inhibitory affects on endothelial cells and fibroblasts. These findings characterize a novel role for the CXCR3B in regulating cellular function. Taken together these data show a role for CXCR3B in regulating pericyte function.

The stellate vascular smooth muscle cell phenotype is induced by IL-1β via the secretion of PGE2 and subsequent cAMP-dependent protein kinase A activation

Atherosclerosis development is associated with morphological changes to intimal cells, leading to a stellate cell phenotype. In this study, we aimed to determine whether and how key pro-atherogenic cytokines present in atherosclerotic plaques (IL-1β, TNFα and IFNγ) could induce this phenotype, as these molecules are known to trigger the transdifferentiation of vascular smooth muscle cells (VSMCs). We found that, IL-1β was the only major inflammatory mediator tested capable of inducing a stellate morphology in VSMCs. This finding was confirmed by staining for F-actin and vinculin at focal adhesions, as these two markers were disrupted only by IL-1β. We then investigated the possible association of this IL-1β-dependent change in morphology with an increase in intracellular cAMP concentration ([cAMP]), using the FRET-based biosensor for cAMP (T)Epac(VV). Experiments in the presence of IL-1β or medium conditioned by IL-1β-treated VSMCs and pharmacological tools demonstrated that the long-term increase in intracellular cAMP concentration was induced by the secretion of an autocrine/paracrine mediator, prostaglandin E₂(PGE₂), acting through the EP4 receptor. Finally, by knocking down the expression of the regulatory subunit PKAR1α, thereby reproducing the effects of IL-1β and PGE₂ on VSMCs, we demonstrated the contribution of PKA activity to the observed behavior of VSMCs.

Elevated Concentration of Interferon-Inducible Protein of 10 kD (IP-10) Is Associated With Coronary Atherosclerosis

Several studies have shown that various chemokines are more highly expressed in atherosclerotic plaques than in normal vessel walls. In the present study, we investigated the relationship between coronary atherosclerosis and noteworthy chemokines, including interferon-inducible protein of 10 kD (IP-10); monocyte chemoattractant protein 1 (MCP-1); regulated on activation, normal T-cell expressed and secreted (RANTES); and high-sensitivity C-reactive protein (hsCRP), an established marker of atherosclerotic disease. We studied 28 patients who underwent coronary angiography because of suspected coronary artery disease (CAD). CAD was defined as stenosis of more than 50% of the vessel diameter on coronary angiograms. Blood samples were obtained both from the aorta and the coronary sinus (CS) just before coronary angiography. Relative to CAD (-) patients, those who were CAD (+) tended to have higher plasma concentrations of IP-10 in the aorta, as well as significantly higher transcoronary concentration gradients of circulating IP-10. There were no significant differences between the two groups in aortic plasma concentrations or transcoronary concentration gradients of MCP-1, RANTES, and hsCRP. Furthermore, both the aortic plasma concentrations and transcoronary concentration gradients of IP-10 correlated with the Gensini score (r = 0.58 and r = 0.63, respectively, P < 0.01), while the plasma MCP-1, RANTES, and serum hsCRP concentrations did not. This study suggests that IP-10 is a good surrogate marker of coronary atherosclerosis.

3-[(dodecylthiocarbonyl)methyl]-glutarimide attenuates graft arterial disease by suppressing alloimmune responses and vascular smooth muscle cell proliferation

BACKGROUND

Graft arterial disease (GAD) is a major cause of late graft loss after organ transplantation. Alloimmune responses and vascular remodeling eventually cause the transplant organ to develop GAD. In this study, we aimed to limit the development of GAD by inhibiting alloimmune responses and vascular smooth muscle cell (VSMC) proliferation with a new compound, 3-[(dodecylthiocarbonyl)methyl]-glutarimide ([DTCM]-glutarimide), in a murine cardiac model of GAD.

METHODS

The hearts from B6.CH-2 mice were transplanted into C57BL/6 mouse recipients to examine the extent of GAD. The recipients were treated with either vehicle or DTCM-glutarimide intraperitoneally (40 mg/kg per day) for 4 weeks.

RESULTS

The administration of DTCM-glutarimide attenuated GAD formation (luminal occlusion: 37.9 ± 5.9% vs 14.8 ± 5.4%, P < 0.05) by inhibiting the number of graft-infiltrating cells and decreasing alloreactive interferon (IFN)-γ production compared with control mice, as measured by the Enzyme-linked ImmunoSpot assay. In vitro, VSMCs proliferated on stimulation with either basic fibroblast growth factor or IFN-γ and splenocytes after transplantation, but the addition of DTCM-glutarimide resulted in the inhibition of VSMC proliferation. Moreover, DTCM-glutarimide suppressed cyclin D1 expression and inhibited cell cycle progression from G1 to S in VSMCs.

CONCLUSIONS

The compound DTCM-glutarimide suppressed GAD development by inhibiting not only alloimmune responses but also VSMC proliferation in the graft.

The multifaceted functions of CXCL10 in cardiovascular disease

C-X-C motif ligand 10 (CXCL10), or interferon-inducible protein-10, is a small chemokine belonging to the CXC chemokine family. Its members are responsible for leukocyte trafficking and act on tissue cells, like endothelial and vascular smooth muscle cells. CXCL10 is secreted by leukocytes and tissue cells and functions as a chemoattractant, mainly for lymphocytes. After binding to its receptor CXCR3, CXCL10 evokes a range of inflammatory responses: key features in cardiovascular disease (CVD). The role of CXCL10 in CVD has been extensively described, for example for atherosclerosis, aneurysm formation, and myocardial infarction. However, there seems to be a discrepancy between experimental and clinical settings. This discrepancy occurs from differences in biological actions between species (e.g. mice and human), which is dependent on CXCL10 signaling via different CXCR3 isoforms or CXCR3-independent signaling. This makes translation from experimental to clinical settings challenging. Furthermore, the overall consensus on the actions of CXCL10 in specific CVD models is not yet reached. The purpose of this review is to describe the functions of CXCL10 in different CVDs in both experimental and clinical settings and to highlight and discuss the possible discrepancies and translational difficulties. Furthermore, CXCL10 as a possible biomarker in CVD will be discussed.

Tumor necrosis factor (TNF)-α induction of CXCL10 in endothelial cells requires protein arginine methyltransferase 5 (PRMT5)-mediated nuclear factor (NF)-κB p65 methylation

The chemokine CXCL10/IP-10 facilitates recruitment of Th1-type leukocytes to inflammatory sites. In this study, we show that the arginine methyltransferase PRMT5 is critical for CXCL10 transcription in TNF-α-activated human endothelial cells (EC). We found that depletion of PRMT5 results in significantly reduced levels of CXCL10 mRNA, demonstrating a positive role for PRMT5 in CXCL10 induction. Chromatin immunoprecipitation experiments revealed the presence of the symmetrical dimethylarginine modification catalyzed by PRMT5 associated with the CXCL10 promoter in response to TNF-α. However, symmetrical dimethylarginine-modified proteins were not detected at the promoter in the absence of PRMT5, indicating that PRMT5 is essential for methylation to occur. Furthermore, NF-κB p65, a critical driver of TNF-α-mediated CXCL10 induction, was determined to be methylated at arginine residues. Crucially, RNAi-mediated PRMT5 depletion abrogated p65 methylation and CXCL10 promoter binding. Mass spectrometric analysis in EC identified five dimethylated arginine residues in p65, four of which are uncharacterized in the literature. Expression of Arg-to-Lys point mutants of p65 demonstrated that both Arg-30 and Arg-35 must be dimethylated to achieve full CXCL10 expression. In conclusion, we have identified previously uncharacterized p65 post-translational modifications critical for CXCL10 induction.

Absence of chemokine (C-x-C motif) ligand 10 diminishes perfusion recovery after local arterial occlusion in mice

OBJECTIVE

In arteriogenesis, pre-existing anastomoses undergo enlargement to restore blood flow in ischemic tissues. Chemokine (C-X-C motif) ligand 10 (CXCL10) is secreted after Toll-like receptor activation. Toll-like receptors are involved in arteriogenesis; however, the role of CXCL10 is still unclear. In this study, we investigated the role for CXCL10 in a murine hindlimb ischemia model.

APPROACH AND RESULTS

Unilateral femoral artery ligation was performed in wild-type (WT) and CXCL10(-/-) knockout (KO) mice and perfusion recovery was measured using laser-Doppler perfusion analysis. Perfusion recovery was significantly lower in KO mice compared with WT at days 4 and 7 after surgery (KO versus WT: 28±5% versus 81±13% at day 4; P=0.003 and 57±12% versus 107±8% at day 7; P=0.003). Vessel measurements of α-smooth muscle actin-positive vessels revealed increasing numbers in time after surgery, which was significantly higher in WT when compared with that in KO. Furthermore, α-smooth muscle actin-positive vessels were significantly larger in WT when compared with those in KO at day 7 (wall thickness, P<0.001; lumen area, P=0.003). Local inflammation was assessed in hindlimb muscles, but this did not differ between WT and KO. Chimerization experiments analyzing perfusion recovery and histology revealed an equal contribution for bone marrow-derived and circulating CXCL10. Migration assays showed a stimulating role for both intrinsic and extrinsic CXCL10 in vascular smooth muscle cell migration.

CONCLUSIONS

CXCL10 plays a causal role in arteriogenesis. Bone marrow-derived CXCL10 and tissue-derived CXCL10 play a critical role in accelerating perfusion recovery after arterial occlusion in mice probably by promoting vascular smooth muscle cell recruitment and maturation of pre-existing anastomoses.

Prognostic relevance of baseline pro- and anti-inflammatory markers in STEMI: an APEX AMI substudy

BACKGROUND

Plaque rupture, acute ischemia, and necrosis in acute coronary syndromes are accompanied by concurrent pro- and anti-inflammatory cascades. Whether STEMI clinical prediction models can be improved with the addition of baseline inflammatory biomarkers remains unknown.

METHODS

In an APEX-AMI trial substudy, 772 patients had a panel of 9 inflammatory serum biomarkers, high sensitivity C reactive protein (hsCRP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measured at baseline after randomization. Baseline biomarkers were incorporated into a clinical prediction model for a composite of 90-day death, shock, or heart failure. Incremental prognostic value was assessed using Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI).

RESULTS

Individually, several biomarkers were independent predictors of clinical outcome: hsCRP (hazard ratio [HR] 1.12; 95% confidence interval [CI], 1.03-1.21; p=0.007, per doubling), NT-proBNP (HR 1.14; 95% CI, 1.06-1.23; p<0.001, per doubling), interleukin (IL)-6 (HR 1.26; 95% CI, 1.12-1.41;p<0.001, per doubling), and inducible protein-10 (IP-10) (HR 0.86; 95% CI, 0.76-0.98; p<0.025, per doubling). The addition of baseline NT-proBNP (NRI 8.6%, p=0.028; IDI 0.030, p<0.001) and IL-6 (NRI 8.8%, p=0.012; IDI 0.036, p<0.001) improved the clinical risk prediction model and the addition of hsCRP (NRI 6.5%, p=0.069; IDI 0.018, p=0.004) yielded minimal improvement. After incorporating NT-proBNP into the model, the remaining biomarkers added little additional predictive value.

CONCLUSIONS

Multiple inflammatory biomarkers independently predicted 90-day death, shock or heart failure; however, they added little value to a clinical prediction model that included NT-proBNP. Future studies of inflammatory biomarkers in STEMI should report incremental value in a prediction model that includes NT-proBNP.

Trophoblast-induced changes in C-x-C motif chemokine 10 expression contribute to vascular smooth muscle cell dedifferentiation during spiral artery remodeling

OBJECTIVE

During pregnancy, fetal trophoblast disrupt endothelial cell and vascular smooth muscle cell (VSMC) interactions in spiral arteries of the maternal decidua to enable increased nutritional and oxygen delivery to the fetus. Little is known regarding this transformation because of difficulties of studying human pregnancy in vivo. This study investigated how trophoblast-secreted factors affect the interactions of vascular cells and the differentiation status of VSMC during spiral arteries remodeling using 3-dimensional vascular spheroid coculture.

METHODS AND RESULTS

Endothelial cell and VSMC were cocultured in hanging droplets to form spheroids representing an inverted vessel lumen. Control or conditioned media from an extravillous trophoblast (EVT) cell line was incubated with vascular spheroids for 24 hours. Spheroid RNA was then analyzed by Illumina Sentrix BeadChip array. Spheroids incubated with EVT conditioned medium showed significant up/downregulation of 101 genes (>1.5-fold; P<0.05), including an upregulation of C-X-C motif chemokine 10 (IP-10). C-X-C motif chemokine 10 expression was confirmed by qualitative real-time PCR and Western blot analysis of spheroids, and immunohistochemistry of first trimester decidua and ex vivo dissected nonplacental bed spiral arteries. EVT conditioned medium reduced VSMC expression of differentiation markers, and both EVT conditioned medium and C-X-C motif chemokine 10 increased motility of VSMC indicating dedifferentiation of VSMC.

CONCLUSIONS

EVT-induced C-X-C motif chemokine 10 expression may contribute to spiral arteries remodeling during pregnancy by altering the motility and differentiation status of the VSMC in the vessel.

Tumoral lymphocytic infiltration and expression of the chemokine CXCL10 in breast cancers from the Ontario Familial Breast Cancer Registry

PURPOSE

Breast carcinomas, including basal and hereditary cases, often present with a prominent tumoral lymphocytic infiltrate. Chemokines could play a role in attracting these cells and contribute to tumor progression. We explored tumoral expression of CXCL10 and determined the relationship between CXCL10 and lymphocytic infiltrate in a cohort of breast cancers.

EXPERIMENTAL DESIGN

Using tissue microarrays of 364 breast tumors, we evaluated expression of CXCL10 and its receptor, CXCR3, in relation to histopathologic features, biomarkers, and lymphocyte markers. In addition, we overexpressed CXCL10 and CXCR3 in MCF7 breast cancer cells and monitored T-lymphocyte migration and invasion.

RESULTS

Forty-five percent of tumors expressed CXCL10, and a significant association was found with CXCR3 and lymphocytic infiltrate. Further characterization of the lymphocytic infiltrate revealed an association with CXCL10 expression for peritumoral CD4+ and CD8+ lymphocytes. CD8+ intratumoral lymphocytes, FOXP3+ regulatory T cells (Tregs), and T-BET+ T(H)1 cells were associated with BRCA1 and basal tumors. Conditioned media from MCF7 cells overexpressing both CXCL10 and CXCR3 increased T-lymphocyte migration and invasion.

CONCLUSIONS

Our findings suggest that CXCL10 may act in a paracrine manner, affecting the tumor microenvironment, and in an autocrine manner, acting on the tumor cells themselves and may play a role in tumor invasiveness and progression. The CXCL10-CXCR3 axis can serve as a potential target in BRCA1 and basal breast cancers, which present with a prominent lymphocytic infiltrate and a poor prognosis. Clin Cancer Res; 19(2); 336-46. ©2012 AACR.

The effect of sleep apnea and insomnia on blood levels of leptin, insulin resistance, IP-10, and hydrogen sulfide in type 2 diabetic patients

INTRODUCTION

Sleep deficits associated with sleep apnea and insomnia increase the risk of vascular inflammation and insulin resistance. This study examined the hypothesis that inflammation markers are higher in those diabetic patients who experience sleep deficits compared with those without any history of a sleep disorder.

METHODS

Fasting blood was obtained after written informed consent, and sleep disorder histories were obtained from type 2 diabetic patients (n=81) attending clinics of the Louisiana State University Health Sciences Center.

RESULTS

There was a significant correlation between body weight and leptin, and leptin in turn was significantly correlated with 10-kDa interferon-γ-induced protein (IP-10) levels and insulin resistance in type 2 diabetic patients. Fasting blood levels of leptin, IP-10, and insulin resistance were significantly elevated in patients with sleep deficits compared with diabetics with normal sleep patterns. There were no differences in glycosylated hemoglobin (HbA1c) or fasting glucose in patients with sleep deficits compared with those with normal sleep patterns. Sleep deficits increase circulating levels of leptin, IP-10, and insulin resistance compared to levels seen in patients with diabetes who reported no difficulty with sleep. Patients with sleep apnea had significantly lower hydrogen sulfide (H(2)S) levels compared with patients with normal sleep patterns or patients with insomnia. Low levels of circulating H(2)S could contribute to higher vascular inflammation in patients with sleep apnea.

CONCLUSIONS

These results suggest that sleep apnea is associated with a decrease in circulating H(2)S and sleep disorders increase the risk of inflammation and insulin resistance, which can contribute to the increased risk of vascular disease in subjects with type 2 diabetes.

Interference of IP-10 expression inhibits vascular smooth muscle cell proliferation and intimal hyperplasia in carotid artery: a new insight in the prevention of restenosis

After vascular angioplasty, vascular smooth muscle cell (VSMC) proliferation causes atherosclerosis and intimal hyperplasia leading to restenosis. Interferon-γ-inducible protein (IP)-10 plays a role in atherogenesis, but the mechanism remains unclear. We evaluated the role of IP-10 in intimal hyperplasia and restenosis. IP-10 expression was determined in arterial specimens from 20 arteriosclerotic obliteration patients and 6 healthy individuals. VSMCs were stimulated in vitro with IFN-γ and transfected with IP-10 siRNA. Silencing was verified with RT-PCR/Western blot; cell proliferation rate was detected by methyl-thiazol-tetrazolium. The carotid artery model of atherosclerosis injury was established with IP-10 siRNA. IP-10 expression was detected at 1 and 4 weeks using RT-PCR and immunohistochemistry. Artery morphology was assessed with hematoxylin-and-eosin staining, and intimal hyperplasia was evaluated by electron microscopy. IP-10 was overexpressed in arteriosclerotic obliteration group compared with control group (P < 0.05). IP-10 expression in transfected group was significantly lower than in untransfected group. The intima-to-media ratio of transfected group at 4 weeks was lower than that of untransfected group (P < 0.01). The transfected group exhibited more regular intimal structure and less hyperplasia under electron microscopy. We, therefore, concluded that IP-10 played an important role in intimal hyperplasia as siRNA-mediated IP-10 silencing inhibited aberrant VSMCs hyperplasia and reduced restenosis.

CXCL10: a candidate biomarker in transplantation

Interferon (IFN) γ-induced protein 10 kDa (IP-10) or C-X-C motif chemokine 10 (CXCL10) is a small cytokine belonging to the CXC chemokine family. This family of signaling molecules is known to control several biological functions and to also play pivotal roles in disease initiation and progression. By binding to its specific cognate receptor CXCR3, CXCL10 critically regulates chemotaxis during several immune-inflammatory processes. In particular, this chemokine controls chemotaxis during the inflammatory response resulting from allograft rejection after transplantation. Interestingly, a strong association has been described between CXCL10 production, immune response and the fate of the graft following allotransplantation. Enhanced CXCL10 production has been observed in recipients of transplants of different organs. This enhanced production likely comes from either the graft or the immune cells and is correlated with an increase in the concentration of circulating CXCL10. Because CXCL10 can be easily measured in the serum and plasma from a patient, the detection and quantitation of circulating CXCL10 could be used to reveal a transplant recipient's immune status. The purpose of this review is to examine the critical role of CXCL10 in the pathogenesis of allograft rejection following organ transplantation. This important role highlights the potential utilization of CXCL10 not only as a therapeutic target but also as a biomarker to predict the severity of rejection, to monitor the inflammatory status of organ recipients and, hopefully, to fine-tune patient therapy in transplantation.

Regulation of CCL5 expression in smooth muscle cells following arterial injury

Chemokines play a crucial role in inflammation and in the pathophysiology of atherosclerosis by recruiting inflammatory immune cells to the endothelium. Chemokine CCL5 has been shown to be involved in atherosclerosis progression. However, little is known about how CCL5 is regulated in vascular smooth muscle cells. In this study we report that CCL5 mRNA expression was induced and peaked in aorta at day 7 and then declined after balloon artery injury, whereas IP-10 and MCP-1 mRNA expression were induced and peaked at day 3 and then rapidly declined.

The expression of CCL5 receptors (CCR1, 3 & 5) were also rapidly induced and then declined except CCR5 which expression was still relatively high at day 14 after balloon injury. In rat smooth muscle cells (SMCs), similar as in aorta CCL5 mRNA expression was induced and kept increasing after LPS plus IFN-gamma stimulation, whereas IP-10 mRNA expression was rapidly induced and then declined. Our data further indicate that induction of CCL5 expression in SMCs was mediated by IRF-1 via binding to the IRF-1 response element in CCL5 promoter. Moreover, p38 MAPK was involved in suppression of CCL5 and IP-10 expression in SMCs through common upstream molecule MKK3. The downstream molecule MK2 was required for p38-mediated CCL5 but not IP-10 inhibition. Our findings indicate that CCL5 induction in aorta and SMCs is mediated by IRF-1 while activation of p38 MAPK signaling inhibits CCL5 and IP-10 expression. Methods targeting MK2 expression could be used to selectively regulate CCL5 but not IP-10 expression in SMCs.

Inflammatory response in human skeletal muscle cells: CXCL10 as a potential therapeutic target

Inflammatory myopathies (IMs) are systemic diseases characterized by a T helper (Th) 1 type inflammatory response and cell infiltrates within skeletal muscles. The mainstay of treatment is drugs aimed at suppressing the immune system - corticosteroids and immunosuppressants. About 25% of patients are non-responders. Skeletal muscle cells seem actively involved in the immune-inflammatory response and not only a target; understanding the molecular bases of IMs might help drug development strategies. Within muscles the interaction between the chemokine interferon (IFN)γ inducible 10 kDa protein, CXCL10 or IP-10, and its specific receptor CXCR3, present on Th1 type infiltrating cells, likely plays a pivotal role, potentially offering the opportunity for therapeutic intervention. We aimed to clarify the involvement of human skeletal muscle cells in inflammatory processes in terms of CXCL10 secretion, to elucidate the engaged molecular mechanism(s) and, finally, to evaluate muscular cell responses, if any, to some immunosuppressants routinely used in IM treatment, such as methylprednisolone, methotrexate, cyclosporin A and Infliximab. We first isolated and characterized human fetal skeletal muscle cells (Hfsmc), which expressed the specific lineage markers and showed the competence to react in the context of an in vitro alloresponse. CXCL10 protein secretion by Hfsmc was similarly induced by the inflammatory cytokines interferon (IFN)γ and tumor necrosis factor (TNF)α, above undetectable control levels, through the activation of Stat1 and NF-kB pathways, respectively; CXCL10 secretion was significantly magnified by cytokine combination, and this synergy was associated to a significant up-regulation of TNFαRII; cytokine-induced CXCL10 secretion was considerably affected only by Infliximab. Our data suggested that human skeletal muscle cells might actively self-promote muscular inflammation by eliciting CXCL10 secretion, which is known to amplify Th1 cell tissue infiltration in vivo. In conclusion, we sustain that pharmacological targeting of CXCL10 within muscular cells might contribute to keep in control pro-Th1 polarization of the immune/inflammatory response.

Atherosclerotic Plaque Stability Is Affected by the Chemokine CXCL10 in Both Mice and Humans

Background. The chemokine CXCL10 is specifically upregulated during experimental development of plaque with an unstable phenotype. In this study we evaluated the functional consequences of these findings in mice and humans. Methods and Results. In ApoE^−/− mice, we induced unstable plaque with using a flow-altering device around the carotid artery. From week 1 to 4, mice were injected with a neutralizing CXCL10 antibody. After 9 weeks, CXCL10 inhibition resulted in a more stable plaque phenotype: collagen increased by 58% (P = 0.002), smooth muscle cell content increased 2-fold (P = 0.03), while macrophage MHC class II expression decreased by 50% (P = 0.005). Also, the size of necrotic cores decreased by 41% (P = 0.01). In 106 human carotid endarterectomy specimens we found that increasing concentrations of CXCL10 strongly associate with an increase in atheromatous plaque phenotype (ANOVA, P = 0.003), with high macrophage, low smooth muscle cell, and low collagen content. Conclusions. In the present study we showed that CXCL10 is associated with the development of vulnerable plaque in human and mice. We conclude that CXCL10 might provide a new lead towards plaque-stabilizing therapy.

Salvianolic acid B suppresses IFN-γ-induced JAK/STAT1 activation in endothelial cells

INTRODUCTION

Dysfunction of the endothelium contributes to pathological conditions of the arterial wall including atherosclerosis as a result of immunological and/or inflammatory responses. Salvianolic acid B (Sal B), a pure and active compound extracted from the Chinese herb Salvia miltiorrhizae (SM) was characterized for its anti-inflammatory and anti-oxidant properties on vascular system.

METHODS AND RESULTS

Sal B pretreatment significantly inhibited the IFN-γ-induced phosphorylations of JAK2 (Tyr 1007/1008) and STAT1 (Tyr701 and Ser727). Consistently, IFN-γ-induced STAT1 downstream targets CXC chemokines' IP-10, Mig, and I-TAC were suppressed by Sal B pretreatment. Sal B inhibited promoter activities of IP-10 and the secretion of IP-10 protein. The monocyte adhesion to IFN-γ-treated ECs was observed to be reduced after Sal B pretreatment. ECs treated with Sal B alone also increased the expression of PIAS1 and SOCS1 which may also contribute to its inhibitory effect on JAK-STAT1 signaling pathways.

CONCLUSIONS

The anti-inflammatory properties of Sal B on IFN-γ-induced JAK-STAT1 activation were demonstrated in the present study which provides a molecular basis for possible therapeutic usage on vascular disorders.

AIP1 prevents graft arteriosclerosis by inhibiting interferon-γ-dependent smooth muscle cell proliferation and intimal expansion

RATIONALE

ASK1-interacting protein-1 (AIP1), a Ras GTPase-activating protein family member, is highly expressed in endothelial cells and vascular smooth musccells (VSMCs). The role of AIP1 in VSMCs and VSMC proliferative disease is not known.

OBJECTIVE

We used mouse graft arteriosclerosis models characterized by VSMC accumulation and intimal expansion to determine the function of AIP1.

METHODS AND RESULTS

In a single minor histocompatibility antigen (male to female)-dependent aorta transplantation model, AIP1 deletion in the graft augmented neointima formation, an effect reversed in AIP1/interferon-γ receptor (IFN-γR) doubly-deficient aorta donors. In a syngeneic aortic transplantation model in which wild-type or AIP1-knockout mouse aortas were transplanted into IFN-γR-deficient recipients and in which neointima formation was induced by intravenous administration of an adenovirus that encoded a mouse IFN-γ transgene, donor grafts from AIP1-knockout mice enhanced IFN-γ-induced VSMC proliferation and neointima formation. Mechanistically, knockout or knockdown of AIP1 in VSMCs significantly enhanced IFN-γ-induced JAK-STAT signaling and IFN-γ-dependent VSMC migration and proliferation, 2 critical steps in neointima formation. Furthermore, AIP1 specifically bound to JAK2 and inhibited its activity.

CONCLUSIONS

AIP1 functions as a negative regulator in IFN-γ-induced intimal formation, in part by downregulating IFN-γ-JAK2-STAT1/3-dependent migratory and proliferative signaling in VSMCs.

STAT1-mediated signal integration between IFNγ and LPS leads to increased EC and SMC activation and monocyte adhesion

Inflammation plays an important role in host defenses against infectious agents and injury, but it also contributes to the pathophysiology of atherosclerosis. Signal transducer and activated transcription 1 (STAT1) has been identified as a point of convergence for the cross talk between the pro-inflammatory cytokine interferon γ (IFNγ) and the Toll-like receptor-4 (TLR4) ligand LPS in immune cells. However, there is no information available on the role of STAT1 in TLR4-mediated progression of atherosclerosis and on potential synergism between lipopolysaccharides (LPS) and IFNγ signaling in cells from the vasculature. Cultured human microvascular endothelial cells (HMECs) exposed to LPS activated STAT1 in a delayed manner that was inhibited by cycloheximide treatment. Pretreatment of HMECs as well as primary vascular smooth muscle cells (VSMCs) with IFNγ followed by LPS resulted in a significant increase in STAT1 phosphorylation compared with both factors alone. Increased STAT1 protein levels, strictly mediated by IFNγ, correlated with the augmented STAT1 phosphorylation that was absent in TLR4(-/-) cells. As assessed by PCR, Western analysis, and ELISA, this coincided with increased expression of the chemokine interferon gamma-induced protein 10 kDa (IP-10) and the adhesion molecule ICAM-1 in a TLR4-dependent manner.The STAT1-inhibitor fludarabine markedly reduced these effects as well as IFNγ and LPS-dependent adhesion of U937 cells to endothelial cells, emphasizing the potential importance of STAT1 in the integration of both signals. With the established roles of IFNγ and TLRs in atherosclerotic pathology, the STAT1-dependent signal integration between IFNγ and TLR in ECs and VSMCs in response to exogenous and endogenous atherogenic ligands could result in amplification of pro-inflammatory responses in the damaged vessel and be a novel mechanism involved in the initiation and progression of atherosclerosis.

Expression and agonist responsiveness of CXCR3 variants in human T lymphocytes

The chemokine receptor CXCR3 and its ligands CXCL9, CXCL10 and CXCL11 are involved in variety of inflammatory disorders including multiple sclerosis, rheumatoid arthritis, psoriasis and sarcoidosis. Two alternatively spliced variants of the human CXCR3-A receptor have been described, termed CXCR3-B and CXCR3-alt. Human CXCR3-B binds CXCL9, CXCL10, CXCL11 as well as an additional ligand CXCL4. In contrast, CXCR3-alt only binds CXCL11. We report that CXCL4 induces intracellular calcium mobilization as well as Akt and p44/p42 extracellular signal-regulated kinase phosphorylation, in activated human T lymphocytes. These responses have similar concentration dependence and time-courses to those induced by established CXCR3 agonists. Moreover, phosphorylation of Akt and p44/p42 is inhibited by pertussis toxin, suggesting coupling to Gα(i) protein. Surprisingly, and in contrast with the other CXCR3 agonists, stimulation of T lymphocytes with CXCL4 failed to elicit migratory responses and did not lead to loss of surface CXCR3 expression. Taken together, our findings show that, although CXCL4 is coupled to downstream biochemical machinery, its role in T cells is probably distinct from that of CXCR3-A agonists.

Microinflammation is a common risk factor for progression of nephropathy and atherosclerosis in Japanese patients with type 2 diabetes

AIM

This study aimed to evaluate the change of serum levels of proinflammatory molecules in patients with type 2 diabetes and clarify the involvement of these molecules in diabetic nephropathy and atherosclerosis.

METHODS

Sixty-six Japanese type 2 diabetic patients (T2DM) and 39 healthy control subjects were enrolled. We assessed clinical parameters, urinary albumin excretion rate (AER), brachial-ankle pulse wave velocity (baPWV), intima media thickness (IMT) and serum levels of proinflammatory molecules.

RESULTS

Serum levels of IL-6, IP-10 and MCP-1 were significantly higher in T2DM than in control subjects. In T2DM, serum levels of high-sensitivity (hs) CRP, IP-10, hsTNF-alpha, VCAM-1 and E-selectin were positively correlated with AER. Serum levels of IP-10, hsTNF-alpha and VCAM-1 were positively correlated with baPWV. Serum levels of hsCRP, IL-6, IP-10 and hsTNF-alpha were positively correlated with IMT. Multiple linear regression analysis revealed that serum levels of hsTNF-alpha were independently associated with AER (beta=0.235, P=0.038) and serum levels of IP-10 were independently associated with baPWV (beta=0.209, P=0.047) and IMT (beta=0.303, P=0.032).

CONCLUSION

Our results suggest that low-grade inflammation, microinflammation, may be a common risk factor for diabetic nephropathy and atherosclerosis in Japanese type 2 diabetic patients.

CC chemokine receptor-1 activates intimal smooth muscle-like cells in graft arterial disease

BACKGROUND

Graft arterial disease (GAD) limits long-term solid-organ allograft survival. The thickened intima in GAD contains smooth muscle-like cells (SMLCs), leukocytes, and extracellular matrix. The intimal SMLCs in mouse GAD lesions differ from medial smooth muscle cells in their function and phenotype. Although intimal SMLCs may originate by migration and modulation of donor medial cells or by recruitment of host-derived precursors, the mechanisms that underlie their localization within grafts and the factors that drive these processes remain unclear.

METHODS AND RESULTS

This study of aortic transplantation in mice demonstrated an important function for chemokines beyond their traditional role in leukocyte recruitment and activation. Intimal SMLCs, but not medial smooth muscle cells, express functional CC chemokine receptor-1 (CCR1) and respond to RANTES by increased migration and proliferation. Although RANTES infusion in vivo promoted inflammatory cell accumulation in the adventitia of aortic allografts of wild-type and CCR1-deficient recipients, it increased GAD intimal thickening with SMLC proliferation in only the wild-type hosts. Aortic allografts transplanted into CCR1-deficient mice after wild-type bone marrow transplantation did not develop intimal lesions, which indicates that CCR1-bearing inflammatory cells do not contribute to intimal lesion formation. Moreover, RANTES induced SMLC proliferation in vitro but did not promote medial smooth muscle cell growth. Blockade of CCR5 attenuated RANTES-induced T-cell and monocyte/macrophage proliferation but did not affect RANTES-induced SMLC proliferation, consistent with a larger role of CCR1-binding chemokines in SMLC migration and proliferation and GAD development.

CONCLUSIONS

These studies provide a novel mechanistic insight into the formation of vascular intimal hyperplasia and suggest a novel therapeutic strategy for preventing allograft arteriopathy.

Increased secretion of IP-10 from monocytes under hyperglycemia is via the TLR2 and TLR4 pathway

Among the chemokines, members of the CXC family include IP-10 (interferon-gamma induced protein of 10kDa). Elevated serum IP-10 levels have been shown in diabetes. However, there is a paucity of data examining the sources and regulation of IP-10 under hyperglycemic conditions and this was the overall aim of the study. Type 1 diabetes (T1DM) is a pro-inflammatory state. We previously demonstrated increased toll like receptor (TLR) 2 and 4 activation in monocytes of T1DM patients. Thus, we also examined the role of the TLR pathway in modulating IP-10 release from human monocytes under hyperglycemia. Also, circulating and monocytic levels of IP-10 in patients with T1DM with and without microvascular complications (T1DM-MV and T1DM) and controls (C) was assessed. Under HG, IP-10 mRNA and protein were significantly increased compared to normoglycemia. Incubation of monocytes with dominant negative Ikb but not control vector significantly abrogated HG-induced IP-10 release. Furthermore, both TLR2 siRNA as well as TLR4 siRNA, either alone or in combination significantly abrogated HG-induced IP-10 release. Serum and monocytic levels of IP-10 were significantly increased in T1DM and T1DM-MV compared to matched controls. Thus, we demonstrate increased circulating and monocytic IP-10 in T1DM. Down-regulation of TLR2 and TLR4 abrogates HG-induced IP-10 release via NF-kappaB inhibition.

Predictive role of pretransplant serum CXCL10 for cardiac acute rejection

BACKGROUND

The detection of acute rejection in heart transplantation remains an important feature of transplant management, especially in the early phase. Frequent surveillance with endomyocardial biopsy is necessary, even though it is an invasive procedure and carries a certain risk. Hence, noninvasive biomarkers able to predict acute rejection could be a further helpful tool in patient management. The interferon-gamma-inducible chemokine CXCL10 is required for initiation and development of graft failure caused by acute or chronic rejection. It has been reported that CXCL10 serum level is predictive of graft loss in kidney graft recipients. In the present study, we investigated whether pretransplant CXCL10 serum level may be a predictive noninvasive biomarker in heart transplant (HTx) recipients, as well.

METHODS

Sera from 143 patients undergoing orthotopic heart transplantation were collected before surgery and tested for CXCL10 and CCL22 and compared with serum samples from healthy subjects.

RESULTS

We found that basal CXCL10 serum levels in HTx recipients were significantly higher than in healthy subjects, whereas no difference was seen in CCL22 levels. Among HTx recipients, CXCL10 serum levels of rejectors were significantly higher than in nonrejectors. Our results showed that CXCL10 was a significant independent risk factor of several variables and had the highest predictive value for early acute heart rejection, with 160 pg/mL cutoff value.

CONCLUSIONS

In HTx recipients, measurement of pretransplant CXCL10 serum levels could be a clinically useful tool for predicting cardiac acute rejection, especially in the early posttransplant period.

Immunomodulatory effects of BXL-01-0029, a less hypercalcemic vitamin D analogue, in human cardiomyocytes and T cells

Current immunosuppressive protocols have reduced rejection occurrence in heart transplantation; nevertheless, management of heart transplant recipients is accompanied by major adverse effects, due to drug doses close to toxic range. In allograft rejection, characterized by T-helper 1 (Th1) cell-mediated response, the CXCL10-CXCR3 axis plays a pivotal role in triggering a self-promoting inflammatory loop. Indeed, CXCL10 intragraft production, required for initiation and development of graft failure, supports organ infiltration by Th1 cells. Thus, targeting the CXCL10-CXCR3 axis while avoiding generalized immunosuppression, may be of therapeutic significance. Based on preclinical evidence for immunoregulatory properties of vitamin D receptor agonists, we propose that a less hypercalcemic vitamin D analogue, BXL-01-0029, might have the potential to contribute to rejection management. We investigated the effect of BXL-01-0029 on CXCL10 secretion induced by proinflammatory stimuli, both in human isolated cardiomyocytes (Hfcm) and purified CD4+ T cells. Mycophenolic acid (MPA), the active agent of mycophenolate mofetil, was used for comparison. BXL-01-0029 inhibited IFNgamma and TNFalpha-induced CXCL10 secretion by Hfcm more potently than MPA, impairing cytokine synergy and pathways. BXL-01-0029 reduced also CXCL10 protein secretion and gene expression by CD4+ T cells. Furthermore, BXL-01-0029 did not exert any toxic effect onto both cell types, suggesting its possible use as a dose-reducing agent for conventional immunosuppressive drugs in clinical transplantation.

Isolation, sequence analysis and expression profile of a novel porcine gene, CXCL10, differentially expressed in the Longissimus dorsi muscle tissues from Meishan, Meishan x Large White cross and Large White pigs

In order to detect the molecular mechanism of heterosis in pigs, the mRNA differential display (DD) technique was performed to investigate the differences in gene expression in the Longissimus dorsi muscle tissues from Meishan (MS), Meishan x Large White (ML) cross and Large White (LW) pigs. One novel gene that was differentially expressed was identified using semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and its full-length cDNA sequence was obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 104 amino acids that contains the putative conserved domain of the chemokine CXC which could be designated as chemokine cd00273 subgroup and this protein has high homology with the small inducible cytokine B10 precursor (CXCL10) of five species - dog(87%), human (84%), monkey (84%), mouse (75%) and rat (70%) - so that it can be defined as swine small inducible cytokine B10 precursor. The phylogenetic tree analysis revealed that the swine CXCL10 has a closer genetic relationship with the CXCL10 of dog than with those of human, monkey, mouse and rat. The tissue expression analysis indicated that the swine CXCL10 gene is more highly expressed in muscle and weakly expressed in fat and kidney. The genomic sequence of swine CXCL10 gene was finally amplified and result revealed that the swine CXCL10 gene contains four exons and three introns. Our experiment is the first to establish the primary foundation for further research on the swine CXCL10 gene.

Role of chemokines in endocrine autoimmune diseases

Chemokines are a group of peptides of low molecular weight that induce the chemotaxis of different leukocyte subtypes. The major function of chemokines is the recruitment of leukocytes to inflammation sites, but they also play a role in tumoral growth, angiogenesis, and organ sclerosis. In the last few years, experimental evidence accumulated supporting the concept that interferon-gamma (IFN-gamma) inducible chemokines (CXCL9, CXCL10, and CXCL11) and their receptor, CXCR3, play an important role in the initial stage of autoimmune disorders involving endocrine glands. The fact that, after IFN-gamma stimulation, endocrine epithelial cells secrete CXCL10, which in turn recruits type 1 T helper lymphocytes expressing CXCR3 and secreting IFN-gamma, thus perpetuating autoimmune inflammation, strongly supports the concept that chemokines play an important role in endocrine autoimmunity. This article reviews the recent literature including basic science, animal models, and clinical studies, regarding the role of these chemokines in autoimmune endocrine diseases. The potential clinical applications of assaying the serum levels of CXCL10 and the value of such measurements are reviewed. Clinical studies addressing the issue of a role for serum CXCL10 measurement in Graves' disease, Graves' ophthalmopathy, chronic autoimmune thyroiditis, type 1 diabetes mellitus, and Addison's disease have been considered. The principal aim was to propose that chemokines, and in particular CXCL10, should no longer be considered as belonging exclusively to basic science, but rather should be used for providing new insights in the clinical management of patients with endocrine autoimmune diseases.

CXCR3-mediated T-cell chemotaxis involves ZAP-70 and is regulated by signalling through the T-cell receptor

The chemokine receptor CXCR3 is critical for the function of activated T cells. We studied the molecular mechanisms of CXCR3 signalling. The addition of CXCR3 ligands to normal human T cells expressing CXCR3 led to the tyrosine phosphorylation of multiple proteins. Addition of the same ligands to Jurkat T cells engineered to express CXCR3 induced tyrosine phosphorylation of proteins with molecular weights similar to those in normal cells. Immunoblotting with phosphotyrosine-specific antibodies identified Zeta-associated protein of 70,000 molecular weight (ZAP-70), linker for the activation of T cells (LAT), and phospholipase-C-gamma1 (PLCgamma1) to be among the proteins that become phosphorylated upon CXCR3 activation. ZAP-70 was phosphorylated on tyrosine 319, LAT on tyrosines 171 and 191, and PLCgamma1 on tyrosine 783. The ZAP-70 inhibitor piceatannol reduced CXCR3-mediated tyrosine phosphorylation of ZAP-70, LAT, PLCgamma1 and mitogen-activated protein kinase Erk and it reduced CXCL10-mediated chemotaxis of both CXCR3-transfected Jurkat T cells and normal T cells expressing CXCR3. These results are consistent with the involvement of ZAP-70 in CXCR3-mediated protein tyrosine phosphorylation and CXCR3-induced T-cell chemotaxis. Studies with the Lck-deficient Jurkat T-cell line, JCAM1.6, demonstrated that phosphorylation of ZAP-70 after CXCR3 activation is a Lck-dependent process. Finally, stimulating CXCR3-expressing Jurkat T cells and normal T cells expressing CXCR3 through the T-cell receptor attenuated CXCR3-induced tyrosine phosphorylation and CXCR3-mediated T-cell migration, indicating the occurrence of cross-talk between T-cell receptor and CXCR3-signalling pathways. These results shed light on the mechanisms of CXCR3 signalling. Such information could be useful when designing therapeutic strategies to regulate T-cell function.

The expression and possible roles of chemokine CXCL11 and its receptor CXCR3 in the human endometrium

IFN-gamma secreted by a human embryo and trophoblast cells during implantation is suggested to play an important role in implantation and pregnancy. In the present study, we explored expression and possible functions of CXCL11, a CXC chemokine strongly induced by IFN-gamma, and its receptor CXCR3 in the human endometrium. Secreted CXCL11 protein was not detected in cultured endometrial stromal cells (ESC) but was detected in cultured endometrial epithelial cells (EEC). IFN-gamma stimulated the protein levels of CXCL11 in a dose-dependent manner in EEC and ESC. CXCL11 secreted from EEC with 100 ng/ml IFN-gamma was 220-fold of the control, and 100-fold as compared with that secreted from ESC with the same dose of IFN-gamma. CXCR3 was expressed in EEC, ESC, and trophoblast cells. Addition of IFN-gamma to EEC increased the chemotactic activity of its culture medium to trophoblast cells and T cells, and the effect was suppressed by immunoneutralization with Abs of three CXCR3 ligands, including anti-CXCL11 Ab. CXCL11 significantly increased BrdU incorporation of ESC, which was inhibited by a p42/44 MAPK pathway inhibitor PD98059. In contrast, CXCL11 significantly decreased BrdU incorporation and increased the release of lactate dehydrogenase and the positive staining of annexin V in EEC. These findings suggest that IFN-gamma promotes implantation by stimulating EEC to produce CXCL11, which induces migration of trophoblast cells and T cells, proliferation of ESC, and apoptosis of EEC.

Overexpression of CXCL10 in human prostate LNCaP cells activates its receptor (CXCR3) expression and inhibits cell proliferation

Chronic or recurrent inflammation plays a role in the development of many types of cancer including prostate cancer. CXCL10 (interferon-gamma inducible protein-10, IP-10) is a small secretory protein of 8.7 kDa. Recently, it has been shown that normal prostate epithelial (PZ-HPV-7) cells produce lower amounts of angiogenic CXC chemokines (GRO-alpha, IL-8) and higher amounts of angiostatic chemokines (CXCL10, CXCL11) as compared to prostate cancer cells (CA-HPV-10 and PC-3). Accordingly, we studied the effects of overexpression of CXCL10 in human prostate cancer LNCaP cells. LNCaP cells were transiently transfected with CXCL10 cDNA in pIRES2-EGFP vector. CXCL10, CXCR3, PSA and G3PDH mRNA levels were determined by semi-quantitative conventional and quantitative real-time RT-PCR and fluorescence-activated cell sorting (FACS). The expression of CXCL10 was markedly enhanced in the transfected cells at mRNA and protein levels in the cells. Overexpression of CXCL10 inhibited cell proliferation of the transfected cells by 30%-40% in serum-limited medium (1% FCS in RPMI1640 medium) and decreased PSA production. CXCR3 expression was significantly induced by the overexpression of CXCL10 as determined by RT-PCR and FACS. These results indicated that CXCL10 inhibited LNCaP cell proliferation and decreased PSA production by up-regulation of CXCR3 receptor. CXCL10 may be potentially useful in the treatment of prostate cancer.

Constitutive and regulated expression and secretion of interferon-gamma-inducible protein 10 (IP-10/CXCL10) in human adipocytes

OBJECTIVE

Chemokine secretion by adipocytes has been postulated to initiate leukocyte infiltration in adipose tissue and might mediate an important step in the establishment of obesity-related chronic immune activation. The chemokine interferon (IFN)gamma-inducible protein-10 (IP-10/CXCL10) is a chemoattractant for various leukocyte subsets and has been implicated in the pathogenesis of atherosclerosis. This study investigates whether IP-10 is expressed in human adipocytes and whether its release is regulated by body mass index (BMI) or immunological stimuli.

METHODS

In cultures of human mature adipocytes and in vitro differentiated adipocytes, IP-10 expression under basal conditions and in the presence of IFNgamma, lipopolysaccharide (LPS) or interleukin (IL)-4 was characterized by reverse transcriptase-polymerase chain reaction, Luminex technology and immunofluorescence.

RESULTS

IP-10 was expressed and secreted constitutively in most cultures of mature adipocytes from omental and subcutaneous (s.c.) depots. The association between IP-10 release and donor BMI was not significant. In in vitro differentiated adipocytes from s.c. and mammary depots and in mature s.c. adipocytes, IP-10 secretion was strongly upregulated by IFNgamma, whereas LPS or IL-4 did not affect IP-10 expression in s.c. mature adipocytes. Immunofluorescence confirmed IP-10 expression in adipocytes with abundant lipid droplets.

CONCLUSION

Mature human adipocytes express and secrete the chemokine IP-10 and are thus identified as a novel cellular source of this disease-related immune mediator. IP-10 expression could be significantly induced by IFNgamma, but not by LPS, which points to both similar reactivities and functional differences between adipocytes and innate immune cells.

Differential Expression of Chemokines, Risk of Stable Coronary Heart Disease, and Correlation with Established Cardiovascular Risk Markers

Objective— We investigated the association of several chemokines with the risk of stable coronary heart disease (CHD) in a large case-control study after adjustment for other established risk factors. Furthermore, we analyzed their correlation with various acute-phase proteins, inflammation-associated cytokines, and an adhesion molecule.

Methods and Results— We included 312 patients aged 40 to 68 years with angiographically confirmed and stable CHD and 472 age- and gender-matched controls in this study. The main outcome measure was the odds ratio (OR) for CHD associated with increased levels of interferon (INF)-inducible protein of 10 kd (IP-10), interleukin (IL)-8, regulated on activation normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammation protein 1α (MIP-1α), or eotaxin determined by rigidly evaluated sandwich ELISAs. Serum levels of IP-10 and IL-8 were higher, and serum levels of RANTES were lower in CHD patients when compared with age- and gender-matched controls. In addition, values in the second and top tertile of IP-10 and IL-8 were associated with an increased OR for CHD when compared with values in the bottom tertile [OR for IP-10 (top tertile) was 2.62 (95% CI, 1.79 to 3.85) in the age- and gender-adjusted model and 1.93 (95% CI, 1.23 to 3.04) in the fully adjusted model, and for IL-8, the OR was 1.77 (95% CI, 1.20 to 2.59) and 1.53 (95% CI, 0.98 to 2.39), respectively]; increased RANTES values were associated with a lower OR for CHD [OR, 0.67 (95% CI, 0.47 to 0.96) and 0.61 (95% CI, 0.40 to 0.94)]. Furthermore, positive correlations of IP-10 and IL-8 with several acute-phase proteins or inflammation-associated cytokines were evident, and positive correlations for IP-10 plasma viscosity and intercellular adhesion molecule 1 were also present.

Conclusions— The current study suggests that there may be no universal upregulation of chemokines in CHD-associated inflammation but different upregulation of IP-10 and IL-8 versus downregulation of RANTES; there was no clear disease association for MCP-1, MIP-1α, or eotaxin.