Cardiotrophin-1 stimulates intercellular adhesion molecule-1 and monocyte chemoattractant protein-1 in human aortic endothelial cells

In vitro and in vivo exposure of endothelial cells to dibutyl phthalate promotes monocyte adhesion

The effect of endothelial cells' exposure to dibutyl phthalate (DBP) on monocyte adhesion is largely unknown. We evaluated monocyte adhesion to DBP-exposed endothelial cells by combining three approaches: short-term exposure (24 h) of EA.hy926 cells to 10-6, 10-5, and 10-4 M DBP, long-term exposure (12 weeks) of EA.hy926 cells to 10-9, 10-8, and 10-7 M DBP, and exposure of rats (28 and 90 days) to 100, 500, and 5000 mg DBP/kg food. Monocyte adhesion to human EA.hy926 and rat aortic endothelial cells, expression of selected cellular adhesion molecules and chemokines, and the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) were analyzed. We observed increased monocyte adhesion to DBP-exposed EA.hy926 cells in vitro and to rat aortic endothelium ex vivo. ERK1/2 inhibitor prevented monocyte adhesion to DBP-exposed EA.hy926 cells in short-term exposure experiments. Increased ERK1/2 phosphorylation in rat aortic endothelium and transient decrease in ERK1/2 activation following long-term exposure of EA.hy926 cells to DBP were also observed. In summary, exposure of endothelial cells to DBP promotes monocyte adhesion, thus suggesting a possible role for this phthalate in the development of atherosclerosis. ERK1/2 signaling could be the mediator of monocyte adhesion to DBP-exposed endothelial cells, but only after short-term high-level exposure.

Autocrine Regulation of Interleukin-6 via the Activation of STAT3 and Akt in Cardiac Myxoma Cells

Plasma concentrations of a pleiotropic cytokine, interleukin (IL)-6, are increased in patients with cardiac myxoma. We investigated the regulation of IL-6 in cardiac myxoma. Immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) revealed that IL-6 and its receptors, IL-6 receptor (IL-6R) and gp130, co-existed in the myxoma cells. Myxoma cells were cultured, and an antibody array assay showed that a conditioned medium derived from the cultured myxoma cells contained increased amounts of IL-6. Signal transducer and activator of transcription (STAT) 3 and Akt were constitutively phosphorylated in the myxoma cells. An enzyme-linked immunosorbent assay (ELISA) showed that the myxoma cells spontaneously secreted IL-6 into the culture medium. Real-time PCR revealed that stimulation with IL-6 + soluble IL-6R (sIL6R) significantly increased IL-6 mRNA in the myxoma cells. Pharmacological inhibitors of STAT3 and Akt inhibited the IL-6 + sIL-6R-induced gene expression of IL-6 and the spontaneous secretion of IL-6. In addition, IL-6 + sIL-6R-induced translocation of phosphorylated STAT3 to the nucleus was also blocked by STAT3 inhibitors. This study has demonstrated that IL-6 increases its own production via STAT3 and Akt pathways in cardiac myxoma cells. Autocrine regulation of IL-6 may play an important role in the pathophysiology of patients with cardiac myxoma.

Inhibitory Effects of Simvastatin on IL-33-Induced MCP-1 via the Suppression of the JNK Pathway in Human Vascular Endothelial Cells

An alarmin, interleukin (IL)-33 is a danger signal that causes inflammation, inducing chemotactic proteins such as monocyte chemoattractant protein (MCP)-1 in various cells. As statins have pleiotropic actions including anti-inflammatory properties, we investigated the effects of simvastatin on IL-33-induced MCP-1 expression in human umbilical vein endothelial cells (HUVECs). HUVECs were stimulated with IL-33 in the presence or absence of simvastatin. Gene expression and protein secretion of MCP-1, phosphorylation of mitogen-activated protein kinase (MAPK), nuclear translocation of phosphorylated c-Jun, and human monocyte migration were investigated. Immunocytochemical staining and Western immunoblot analysis revealed that IL-33 augmented MCP-1 protein expression in HUVECs. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) showed that IL-33 significantly increased MCP-1 mRNA and protein secretion, which were suppressed by c-jun N-terminal kinase (JNK) inhibitor SP600125 and p38 MAPK inhibitor SB203580. Simvastatin inhibited IL-33-induced MCP-1 mRNA, protein secretion, phosphorylation of JNK and c-Jun. Additionally, the IL-33-induced nuclear translocation of phosphorylated c-Jun and THP-1 monocyte migration were also blocked by simvastatin. This study demonstrated that IL-33 induces MCP-1 expression via the JNK and p38 MAPK pathways in HUVECs, and that simvastatin inhibits MCP-1 production by selectively suppressing JNK. Simvastatin may inhibit the progression of IL-33-induced inflammation via suppressing JNK to prevent MCP-1 production.

Lack of NPR1 Increases Vascular Endothelial Adhesion through Induction of Integrin Beta 4

Natriuretic peptide receptor 1 (NPR1) serves as a modulator of vascular endothelial homeostasis. Interactions between monocytes and endothelial cells may initiate endothelium dysfunction, which is known as an early hallmark of atherosclerosis. In this study, we performed RNA-sequencing analysis for the aorta of Npr1 knockout (Npr1^+/−) mice and found that differentially expressed genes were significantly related to cell adhesion. This result was supported by an increased expression of intercellular adhesion molecule 1 (ICAM-1) in the aortic endothelium of Npr1^+/− mice. Moreover, we observed that the knockdown of NPR1 increased ICAM-1 expression and promoted THP-1 monocyte adhesion to human umbilical vein endothelial cells (HUVECs). NPR1 overexpression decreased ICAM-1 expression and inhibited the adhesion of monocytes to HUVECs treated by TNF-α (a cell adhesion inducer). Further analysis showed that adhesion-related genes were enriched in the focal adhesion signaling pathway, in which integrin beta 4 (Itgb4) was determined as a key gene. Notably, ITGB4 expression increased in vascular endothelium of Npr1^+/− mice and in NPR1-knockdown HUVECs. The deficiency of ITGB4 decreased ICAM-1 expression and attenuated monocyte adhesion to NPR1-knockdown endothelial cells. Additionally, a reduced NPR1 and an increased ITGB4 expression level were found in an atherosclerosis mouse model. In conclusion, our findings demonstrate that NPR1 deficiency increases vascular endothelial cell adhesion by stimulating ITGB4 expression, which may contribute to the development of atherosclerosis.

Oncostatin M: Risks and Benefits of a Novel Therapeutic Target for Atherosclerosis

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death worldwide. It is predicted that approximately 23.6 million people will die from CVDs annually by 2030. Therefore, there is a great need for an effective therapeutic approach to combat this disease. The European Cardiovascular Target Discovery (CarTarDis) consortium identified Oncostatin M (OSM) as a potential therapeutic target for atherosclerosis. The benefits of modulating OSM - an interleukin (IL)-6 family cytokine - have since been studied for multiple indications. However, as decades of high attrition rates have stressed, the success of a drug target is determined by the fine balance between benefits and the risk of adverse events. Safety issues should therefore not be overlooked.

OBJECTIVE

In this review, a risk/benefit analysis is performed on OSM inhibition in the context of atherosclerosis treatment. First, OSM signaling characteristics and its role in atherosclerosis are described. Next, an overview of in vitro, in vivo, and clinical findings relating to both the benefits and risks of modulating OSM in major organ systems is provided. Based on OSM's biological function and expression profile as well as drug intervention studies, safety concerns of inhibiting this target have been identified, assessed, and ranked for the target population.

CONCLUSION

While OSM may be of therapeutic value in atherosclerosis, drug development should also focus on de-risking the herein identified major safety concerns: tissue remodeling, angiogenesis, bleeding, anemia, and NMDA- and glutamate-induced neurotoxicity. Close monitoring and/or exclusion of patients with various comorbidities may be required for optimal therapeutic benefit.

The effect of parthenolide on methamphetamine-induced blood-brain barrier and astrocyte alterations

BACKGROUND

Methamphetamine abuse is a worldwide concern with long-term health complications. Its impact on neurons has been extensively investigated, and it is currently known that glial cells, including astrocytes, are involved in drug-induced outcomes. Importantly, METH also causes blood-brain barrier (BBB) disruption and astrocytes are critical for BBB (dys)function. Therefore, we aimed to clarify the involvement of neuroinflammation mediated by astrocytes in BBB permeability and brain oedema induced by METH. Further, we aimed to identify a new approach to counteract METH effects.

METHODS

Mice were administered with a METH binge regimen (4 × 10 mg/kg) alone or in combination with parthenolide (PTL; 4 × 1 mg/kg), and hippocampi were analysed. For in vitro studies, mouse primary cultures of astrocytes were exposed to 250 µM METH, alone or co-treated with 10 µM PTL.

RESULTS

We observed a neuroinflammatory response characterized by astrocytic morphological changes and increased TNF-α, iNOS and ICAM-1 protein levels (213.62%, 205.76% and 191.47% of control, respectively). Additionally, brain oedema and BBB disruption were identified by increased water content (81.30% of tissue weight) and albumin (224.40% of control) in the hippocampal tissue, as well as a significant decrease in vessel coverage by astrocytes after METH exposure. Regarding astrocyte cultures, we further identified TNF-α as a key player in METH-induced cell swelling. Importantly, PTL (present in feverfew plant) prevented both animal and in vitro effects induced by METH.

CONCLUSIONS

We provided important insights on brain dysfunction induced by METH, and we also suggest a new approach to counteract such negative effects.

Influences of the IL-6 cytokine family on bone structure and function

The IL-6 family of cytokines comprises a large group of cytokines that all act via the formation of a signaling complex that includes the glycoprotein 130 (gp130) receptor. Despite this, many of these cytokines have unique roles that regulate the activity of bone forming osteoblasts, bone resorbing osteoclasts, bone-resident osteocytes, and cartilage cells (chondrocytes). These include specific functions in craniofacial development, longitudinal bone growth, and the maintenance of trabecular and cortical bone structure, and have been implicated in musculoskeletal pathologies such as craniosynostosis, osteoporosis, rheumatoid arthritis, osteoarthritis, and heterotopic ossifications. This review will work systematically through each member of this family and provide an overview and an update on the expression patterns and functions of each of these cytokines in the skeleton, as well as their negative feedback pathways, particularly suppressor of cytokine signaling 3 (SOCS3). The specific cytokines described are interleukin 6 (IL-6), interleukin 11 (IL-11), oncostatin M (OSM), leukemia inhibitory factor (LIF), cardiotrophin 1 (CT-1), ciliary neurotrophic factor (CNTF), cardiotrophin-like cytokine factor 1 (CLCF1), neuropoietin, humanin and interleukin 27 (IL-27).

Endothelial dysfunction in patients with myocardial ischemia or infarction and nonobstructive coronary arteries

PURPOSE

The syndromes of myocardial infarction/myocardial ischemia with No Obstructive Coronary Artery Disease (MINOCA/INOCA) are seen more and more often. Endothelial dysfunction (ED) leading to ischemic events has been reported in many of these patients. We aimed to compare patients with MINOCA and INOCA regarding brachial artery flow-mediated endothelium-dependent vasodilation (flow-mediated dilation [FMD]) and plasma concentration of cardiotrophin-1 (CT-1).

METHODS

We included 42 patients with MINOCA and 38 patients with INOCA. Endothelial function was assessed by measuring FMD% and nitroglycerin-mediated dilatation (NMD%) in the brachial artery. The plasma level of CT-1 was determined by solid-phase enzyme-linked immunosorbent assay.

RESULTS

FMD% was significantly lower in MINOCA than in INOCA patients (6.45 ± 2.65 vs 8.94 ± 3.32, P < .001), without significant difference in NMD% (10.69 ± 3.19 vs 12.16 ± 3.69, P = .06). Plasma CT-1 levels were not significantly different: 40.1 pg/mL (22.5-102.1) vs 37.2 pg/mL (23.5-67.2), P = .53.

CONCLUSION

Our results suggest worse ED in MINOCA than in INOCA patients, but demonstrated no difference in CT-1 levels between patients with stable and unstable ischemic heart disease and normal coronary arteries.

Cardiotrophin-1 Deficiency Abrogates Atherosclerosis Progression

Cardiotrophin-1 (CT-1) is associated with cardiovascular (CV) diseases. We investigated the effect of CT-1 deficiency in the development and progression of atherosclerosis in double knockout Apoe-/-ct-1-/- mice. Apoe-/- C57Bl/6 or Apoe-/-ct-1-/- C57Bl/6 mice were fed a normal chow diet (NCD) or a high-cholesterol diet (HCD). After sacrifice, serum triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), free fatty acids and systemic paracrine factors were measured. Intraplaque lipid and collagen content were quantified in the aortic sections. Immune cell populations in spleen, lymph nodes and aorta were analysis by flow cytometry. Apoe-/-ct-1-/- mice in accelerated atherosclerosis exhibited a reduction of total cholesterol, LDL-C, atherosclerotic plaques size in the aortic root and in the abdominal aorta and improved plaque stability in comparison to Apoe-/- mice. CT-1 deficiency in Apoe-/- mice on (HCD) promoted atheroprotective immune cell responses, as demonstrated by a rise in plasma anti-inflammatory immune cell populations (regulatory T cells, Tregs; regulatory B cells, Bregs and B1a cells) and atheroprotective IgM antibodies. CT-1 deficiency in advanced atherosclerosis mediated regulation of paracrine factors, such as interleukin (IL)-3, IL-6, IL-9, IL-15, IL-27, CXCL5, MCP-3, MIP-1α and MIP-1β. In a model of advanced atherosclerosis, CT-1 deficiency induced anti-inflammatory and atheroprotective effects which resulted in abrogation of atheroprogression.

Discovery of crucial cytokines associated with abdominal aortic aneurysm formation by protein array analysis

As a common disease, abdominal aortic aneurysm (AAA) features permanently progressively dilated abdominal aorta. Various cytokines are implicated in AAA pathogenesis. Clarification of involved cytokines combined with functional analysis may provide new insights into AAA pathogenesis. Using a mouse model, this study analyzed the cytokine profiles in AAA. Cytokines were measured in AAA tissues of saline control or angiotensin II-treated ApoE−/− mice using an antibody array of 200 cytokines, cytokine receptors, and related proteins. Statistical analysis revealed that 21 of 200 proteins were differentially expressed in AAA. These differentially expressed proteins were subjected to function and pathway enrichment analysis, which revealed that leukocyte migration and positive regulation of cell adhesion were the most significant biological processes. Specific signaling pathways, including Janus kinase/signal transducers and activators of transcription and cytokine–cytokine receptor interaction, were prominent in Kyoto encyclopedia of genes and genomes pathway enrichment analysis. Importantly, our data identified cytokines which had not previously been illustrated in AAA pathogenic pathways. Bivariate correlation analysis between these cytokines and protease activity showed that granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein 1 g, cardiotrophin 1, milk fat globule-EGF factor 8 protein, interleukin 33, and periostin were positively correlated with matrix metalloprotease 1 (MMP-1), MMP-9, cathepsin B, and cathepsin L. G-CSF was positively correlated with cathepsin L. In conclusion, these results demonstrate that cytokine profile is significantly altered in AAA, and that the newly identified crucial cytokines may function potentially in AAA pathogenesis.

Impact statement

Various cytokines are known contributors to abdominal aortic aneurysm (AAA) pathologic processes, but the mechanisms underlying the pathogenesis remains unclear. We illustrated the altered cytokine profiles in AAA by high throughput antibody array of 200 cytokines, cytokine receptors and related proteins, as well as bioinformatics analysis of differentially expressed proteins in lesion tissues from AAA mice infused with angiotensin II. Functional analyses of differentially expressed cytokines showed clustering on cell migration and adhesion processes. More importantly, crucial cytokines whose association with AAA formation had not been established were identified. Significant correlations were found between these cytokines and protease activity. This study identifies several crucial markers for further researches on the molecular basis of AAA.

Interleukin-33 induces interleukin-8 expression via JNK/c-Jun/AP-1 pathway in human umbilical vein endothelial cells

Interleukin (IL)-33 is a member of the IL-1 cytokine family with dual functions as a traditional cytokine and as a transcriptional regulator. We recently reported that IL-33 up-regulated growth regulated oncogene (GRO)-α/CXCL1 expression in human vascular endothelial cells. The aim of this study was to investigate the effect of IL-33 on the expression of IL-8/CXCL8, another member of the CXC-chemokine family, and to elucidate its signaling pathways in human umbilical vein endothelial cells (HUVECs). Immunocytochemical staining and Western immunoblot analysis revealed that IL-33 augmented IL-8 protein expression in HUVECs. Real time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) showed that IL-33 significantly increased IL-8 mRNA and secretion in a dose- and time-dependent manner. IL-33 preferentially stimulated proliferating subconfluent cells, and increased IL-8 secretion to a higher level compared with confluent cells. IL-33 also stimulated phosphorylations of c-Jun N-terminal kinase (JNK) and c-Jun, and enhanced activator protein (AP)-1 DNA-binding activity, all of which were suppressed by SP600125, a JNK inhibitor. Moreover, IL-33-induced IL-8 mRNA and secretion were also suppressed by SP600125. Transfection of c-Jun small interfering RNA into cultured HUVECs significantly reduced the IL-33-induced increase in IL-8 secretion from HUVECs. The present study demonstrates that IL-33 induces IL-8 expression via JNK/c-Jun/AP-1 pathway in human vascular endothelial cells, and provides a new insight into the role of IL-33-induced IL-8 in the pathophysiology of atherosclerosis and vascular inflammation.

Interleukin-33 induces growth-regulated oncogene-α expression and secretion in human umbilical vein endothelial cells

Although interleukin-33 (IL-33), a member of the IL-1 cytokine family, plays proinflammatory roles in immune cells as an "alarmin," little is known regarding the biological actions of IL-33 on vascular endothelial cells. To investigate the effects of IL-33 on vascular endothelial cells, we first screened the IL-33-regulated proteins in human umbilical vein endothelial cells (HUVECs) using a dot blot array and observed that IL-33 markedly increased growth-regulated oncogene-α (GRO-α), a chemokine that is also known as chemokine (C-X-C motif) ligand 1 (CXCL1). Real-time reverse transcription PCR and ELISA demonstrated that IL-33 induced GRO-α expression and secretion in HUVECs in a dose- and a time-dependent manner. Western immunoblot assay revealed that IL-33 activated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH₂-terminal kinase (JNK). In addition, translocation of nuclear factor-κB (NF-κB) p65 to the nucleus of HUVECs was observed by IL-33 stimulation. Furthermore, treatment with pharmacological inhibitors against ERK1/2 (PD98059), JNK (SP600125), or NF-κB (BAY11-7085) significantly suppressed IL-33-induced GRO-α gene expression and secretion from HUVECs. Moreover, immunohistochemical staining demonstrated that IL-33 and GRO-α coexpressed in the endothelium of human carotid atherosclerotic plaque. Taken together, the present study indicates that IL-33 localized in the human atherosclerotic plaque increases GRO-α mRNA expression and protein secretion via activation of ERK1/2, JNK, and NF-κB in HUVECs, suggesting that IL-33 plays an important role in the pathophysiology and development of atherosclerosis.

Potential novel biomarkers of cardiovascular dysfunction and disease: cardiotrophin-1, adipokines and galectin-3

Cardiovascular disease is one of the main burdens of healthcare systems worldwide. Nevertheless, assessing cardiovascular risk in both apparently healthy individuals and low/high-risk patients remains a difficult issue. Already established biomarkers (e.g. brain natriuretic peptide, troponin) have significantly improved the assessment of major cardiovascular events and diseases but cannot be applied to all patients and in some cases do not provide sufficiently accurate information. In this context, new potential biomarkers that reflect various underlying pathophysiological cardiac and vascular modifications are needed. Also, a multiple biomarker evaluation that shows changes in the cardiovascular state is of interest. This review describes the role of selected markers of vascular inflammation, atherosclerosis, atherothrombosis, endothelial dysfunction and cardiovascular fibrosis in the pathogenesis and prognosis of cardiovascular disease: the potential use of cardiotrophin-1, leptin, adiponectin, resistin and galectin-3 as biomarkers for various cardiovascular conditions is discussed.

Cardiotrophin-1: A multifaceted cytokine

Cardiotrophin-1 (CT-1) is a member of the gp130 family of cytokines that have pleiotropic functions on different tissues and cell types. Although many effects of CT-1 have been described on the heart, there is an extensive research showing important protective effects in other organs such as liver, kidney or nervous system. Recently, several studies have pointed out that CT-1 might also play a key role in the regulation of body weight and intermediate metabolism. This paper will review many aspects of CT-1 physiological role in several organs and discuss data for consideration in therapeutic approaches.

A Potential Profibrogenic Role of Biliary Epithelium-Derived Cardiotrophin-1 in Pediatric Cholestatic Liver Disease

As a cytokine of the interleukin-6 family, cardiotrophin-1 (CT-1) has been shown to be an important endogenous protector in liver injury. Our study aimed to investigate the role of CT-1 in liver fibrosis in pediatric cholestatic liver disease (PCLD). CT-1 mRNA and protein expression levels were upregulated in PCLD liver biopsy tissues compared with controls. Immunohistochemistry and confocal microscopy of liver sections showed that CT-1 was predominantly expressed by biliary epithelium cells. Serum CT-1 was elevated significantly in the children with PCLD compared with controls. Serum CT-1 levels exhibited a moderate positive correlation with the Scheuer stage of hepatic fibrosis and serum TB levels and a weak correlation with serum ALP levels. In vitro analysis indicated that LX-2 cells preconditioned with CT-1 exhibited significant increments in proliferation and accumulation of extracellular matrix components, while also positively regulating the STAT3 and p38MAPK pathways. In conclusion, biliary epithelium-derived CT-1 may exert a profibrogenic potential in PCLD.

Betulinic acid attenuates lung injury by modulation of inflammatory cytokine response in experimentally-induced polymicrobial sepsis in mice

Sepsis commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity and mortality. Septic ALI is characterized by excessive production of proinflammatory mediators. It remained refractory to present therapies and new therapies need to be developed to improve further clinical outcomes. Betulinic acid (BA), a pentacyclic lupane group triterpenoid has been shown to have anti-inflammatory activities in many studies. However, its therapeutic efficacy in polymicrobial septic ALI is yet unknown. Therefore, we investigated the effects of BA on septic ALI using cecal ligation and puncture (CLP) model in mice. Vehicle or BA (3, 10, and 30mg/kg) was administered intraperitoneally, 3 times (0, 24 and 48h) before CLP and CLP was done on 49(th)h of the study. Survival rate was observed till 120h post CLP. Lung tissues were collected for analysis by sacrificing mice 18h post CLP. BA at 10 and 30mg/kg dose significantly reduced sepsis-induced mortality and lung injury as implied by attenuated lung histopathological changes, decreased protein and neutrophils infiltration. BA also decreased lung NF-κB expression, cytokine, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 and matrix metalloproteinase-9 levels. These evidences suggest that, the protective effects of BA on lungs are associated with defending action against inflammatory response and BA could be a potential modulatory agent of inflammation in sepsis-induced ALI.

Involvement of fibrinolytic regulators in adhesion of monocytes to vascular endothelial cells induced by glycated LDL and to aorta from diabetic mice

Diabetes mellitus accelerates the development of atherosclerotic cardiovascular diseases. Monocyte adhesion is an early cellular event of atherogenesis. Elevated levels of glyLDL were common in diabetic patients. Our previous studies indicated that HSF1 and p22-phox (a subunit of the NOX complex) were involved in glyLDL-induced up-regulation of PAI-1 in vascular EC. The present study demonstrated that glyLDL significantly increased the adhesion of monocytes to the surface of cultured human umbilical vein or PAEC. Transfection of siRNA for PAI-1, p22-phox, or HSF1 in EC prevented glyLDL-induced monocyte adhesion to EC. uPA siRNA increased monocyte adhesion to EC. Exogenous uPA reduced monocyte adhesion induced by glyLDL or uPA siRNA. Exogenous PAI-1 restored monocyte adhesion to EC inhibited by PAI-1 siRNA or uPA. GlyLDL-induced monocyte adhesion to EC was inhibited by treatment of EC with RAP, an antagonist for LRP, and enhanced by uPAR antibody. The adhesion of monocytes to aorta from leptin db/db diabetic mice was significantly greater than to that from control mice, which was associated with elevated contents of PAI-1, uPA, p22-phox, and HSF1 in hearts of db/db mice. The results suggest that oxidative stress and fibrinolytic regulators (PAI-1, uPA, and uPAR) are implicated in the modulation of glyLDL-induced monocyte adhesion to vascular endothelium, which may play a crucial role in vascular inflammation under diabetes-associated metabolic disorder.

Myocardial cardiotrophin-1 is differentially induced in congenital cardiac defects depending on hypoxemia

ABSTRACT: Aim: Cardiotrophin-1 (CT-1) is upregulated by hypoxemia and hemodynamic overload and is characterized by potent hypertrophic and protective properties on cardiac cells. This study aimed to investigate whether CT-1 is differentially induced in the myocardium of infants with congenital cardiac defects depending on hypoxemia. Methods & results: Infants with Tetralogy of Fallot (n = 8) or with large nonrestrictive ventricular septal defect (n = 8) undergoing corrective surgery were investigated. Expression of CT-1 was assessed at mRNA and protein levels in the right atrial and ventricular myocardium. The activation of the STAT-3 and VEGF were measured. Degradation of cardiac troponin-I served as a marker of myocardial damage. CT-1 was detected in all patients with levels negatively correlating to the arterial oxygen saturation. Higher CT-1 expression in Tetralogy of Fallot patients was associated with activation of the JAK/STAT pathway and higher cardiac troponin-I degradation. Conclusion: CT-1 may mediate myocardial hypertrophy and dysfunction in infants with congenital cardiac defects, particularly in those with hypoxemia.

Stimulatory Effects of Cardiotrophin 1 on Atherosclerosis

Cardiotrophin 1 (CT-1), an interleukin-6 family cytokine, was recently shown to be expressed in the intima of early atherosclerotic lesions in the human carotid artery. CT-1 stimulates proatherogenic molecule expression in human vascular endothelial cells and monocyte migration. However, it has not been reported whether CT-1 accelerates atherosclerosis. This study was performed to examine the stimulatory effects of CT-1 on human macrophage foam cell formation and vascular smooth muscle cell migration and proliferation in vitro, and on the development of atherosclerotic lesions in apolipoprotein E–deficient (ApoE −/− ) mice in vivo. CT-1 was expressed at high levels in endothelial cells and macrophages in both humans and ApoE −/− mice. CT-1 significantly enhanced oxidized low-density lipoprotein–induced foam cell formation associated with increased levels of CD36 and acyl-CoA:cholesterol acyltransferase-1 expression in human monocyte–derived macrophages. CT-1 significantly stimulated the migration, proliferation, and collagen-1 expression in human aortic vascular smooth muscle cells. Four-week infusion of CT-1 into ApoE −/− mice significantly accelerated the development of aortic atherosclerotic lesions with increased monocyte/macrophage infiltration, vascular smooth muscle cell proliferation, and collagen-1 content in the aortic wall. Activation of inflammasome, such as apoptosis-associated speck-like protein containing a caspase recruitment domain, nuclear factor κB, and cyclooxygenase-2, was observed in exudate peritoneal macrophages from ApoE −/− mice infused with CT-1. Infusion of anti–CT-1–neutralizing antibody alone into ApoE −/− mice significantly suppressed monocyte/macrophage infiltration in atherosclerotic lesions. These results indicate that CT-1 accelerates the development of atherosclerotic lesions by stimulating the inflammasome, foam cell formation associated with CD36 and acyl-CoA:cholesterol acyltransferase-1 upregulation in macrophages, and migration, proliferation, and collagen-1 production in vascular smooth muscle cells.

Cardiotrophin-1 induces matrix metalloproteinase-1 in human aortic endothelial cells

Rupture of an atherosclerotic plaque is a key event in the development of cardiovascular disorders, in which matrix metalloproteinase-1 (MMP-1) plays a crucial role by degradation of extracellular matrix resulting in plaque instability. Cardiotrophin-1 (CT-1), a member of interleukin-6-type proinflammatory cytokines, has potent cardiovascular actions and is highly expressed in vascular endothelium, however its role in atherosclerosis has not been fully elucidated to date. The present study was designed to investigate whether CT-1 induces MMP-1 in human aortic endothelial cells (HAECs). Ribonuclease protection assay demonstrated that MMP-1 gene level in HAECs was enhanced by the treatment of CT-1 in a dose- and time-dependent manner. Immunocytochemical staining, Western immunoblot analysis and enzyme-linked immunosorbent assay revealed that CT-1 augmented MMP-1 protein synthesis and secretion. MMP-1 activity assay revealed that MMP-1 present in the supernatant of HAECs was exclusively precursor form. Casein zymography disclosed proteolytic activity in the supernatant of HAECs, which was enhanced by CT-1 treatment. Furthermore, pharmacological inhibitor study indicated the important roles of extracellular signal-regulated kinase (ERK) 1/2, p38 mitogen-activated protein (MAP) kinase, c-Jun N-terminal kinase (JNK) and Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathways in mediating CT-1-induced MMP-1 gene and protein expression. These data reveal for the first time that CT-1 induces the proteolytic potential in HAECs by upregulating MMP-1 expression through ERK1/2, p38 MAP kinase, JNK and JAK/STAT pathways, and suggest that CT-1 may play an important role in the pathophysiology of atherosclerosis and plaque instability.

Flow cytometry and gene expression profiling of immune cells of the carotid plaque and peripheral blood

OBJECTIVES

The relative contribution of the local vs. peripheral inflammation to the atherothrombotic processes is unknown. We compared the inflammatory status of the immune cells of the carotid plaque with similar cells in peripheral circulation of patients with advanced carotid disease (PCDs).

METHODS

Mononuclear cells (MNCs) were extracted from carotid endarterectomy (CEA) samples by enzymatic digestion and subsequent magnetic cell sorting. The cell surface antigenic expressions, and mRNA expression levels were compared between CEA MNCs and peripheral MNCs, using flow cytometry and RT-PCR techniques.

RESULTS

The percentages of resting MNCs were lower, and activated MNCs, particularly monocytes, were higher in the CEAMNCs, as compared to the peripheral MNCs. The percentages of activated T cells and B cells were higher in the peripheral MNCs of PCDs, than in healthy controls (HCs), but the percentages of activated monocytes did not differ between the two groups. The expression levels of both pro-inflammatory/pro-thrombotic (P(38), JNKB-1, Egr-1 PAI-1, MCP-1, TF, MMP-9, HMGB-1, TNF-α, mTOR) and anti-inflammatory (PPAR-γ, TGF-β) mediators were significantly higher in the CEA MNCs as compared to the peripheral MNCs. Furthermore, MMP-9 and PPAR-γ expression levels were higher in the peripheral MNCs of PCDs than HCs.

CONCLUSION

The inflammatory status is higher in the immune cells of the carotid plaque, as compared to those cells in the peripheral blood. The altered expression levels of both pro-inflammatory/pro-thrombotic and anti-inflammatory mediators in the milieu of the plaque suggest that the balance between these various mediators may play a key role in carotid disease progression.

Ciliary neurotrophic factor controls progenitor migration during remyelination in the adult rodent brain

Ciliary neurotrophic factor (CNTF) has been shown to be expressed after brain lesions and in particular after demyelination. Here, we addressed the role of this cytokine in the regulation of neural progenitor migration in the adult rodent brain. Using an acute model of demyelination, we show that CNTF is strongly re-expressed after lesion and is involved in the postlesional mobilization of endogenous progenitors that participate in the myelin regenerative process. We show that CNTF controls the migration of subventricular zone (SVZ)-derived neural progenitors toward the demyelinated corpus callosum. Furthermore, an ectopic source of CNTF in adult healthy brains changes SVZ-derived neural progenitors' migratory behavior that migrate toward the source by activation of the Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway. Using various in vitro assays (Boyden chambers, explants, and video time-lapse imaging), we demonstrate that CNTF controls the directed migration of SVZ-derived progenitors and oligodendrocyte precursors. Altogether, these results demonstrate that in addition to its neuroprotective activity and its role in progenitor survival and maturation, CNTF acts as a chemoattractant and participates in the recruitment of endogenous progenitors during myelin repair.

Vascular effects of glycoprotein130 ligands--part I: pathophysiological role

The vessel wall is no longer considered as only an anatomical barrier for blood cells but is recognized as an active endocrine organ. Dysfunction of the vessel wall occurs in various disease processes including atherosclerosis, hypertension, peripheral artery disease, aneurysms, and transplant and diabetic vasculopathies. Different cytokines were shown to modulate the behavior of the cells, which constitute the vessel wall such as immune cells, endothelial cells and smooth muscle cells. Glycoprotein 130 (gp130) is a common cytokine receptor that controls the activity of a group of cytokines, namely, interleukin (IL)-6, oncostatin M (OSM), IL-11, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), IL-27, and neuropoietin (NP). Gp130 and associated cytokines have abundantly diverse functions. Part I of this review focuses on the pathophysiological functions of gp130 ligands. We specifically describe vascular effects of these molecules and discuss the respective underlying molecular and cellular mechanisms.

Cardiotrophin-1 in cardiovascular regulation

Cardiotrophin (CT)-1 was discovered by coupling expression cloning with an embryonic stem cell-based model of cardiogenesis. Comparison of similarity in amino acid sequence and conformational structure indicates that CT-1 is a member of the interleukin (IL)-6 type cytokine family that shares the transmembrane signaling protein, glycoprotein (gp) 130 as a receptor. These cytokines mediate overlapping pleiotropic actions on a variety of cell types including cardiac myocytes, hepatocytes, megakaryocytes, osteoclasts, and neuronal cells. CT-lmediates its hypertrophic and cytoprotective properties through the Janus kinase/signal transducers and activators of transcription (JAK/STAT), mitogen-activated protein (MAP) kinase, phosphatidylinositol (PI) 3 kinase, and nuclear factor kappa B (NFkappaB) pathways. CT-1 gene and protein are distributed not only in the heart, but also in the pulmonary, renal, gastrointestinal, cerebral, and muscular tissues. CT-1 could also be synthesized and secreted from vascular endothelial cells and adipocytes. CT-1 has hypertrophic actions on the cardiac myocytes, skeletal muscle cells, and smooth muscle cells as well as cytoprotective actions on the cardiac myocytes, neuronal cells, and hepatocytes. CT-1 is circulating in the body, and its plasma concentration is increased in various cardiovascular and renal diseases such as hypertension, congestive heart failure, myocardial infarction, valvular heart disease, metabolic syndrome, and chronic kidney disease. Treatment with CT-1 is beneficial in experimental animal models of cardiovascular diseases. CT-1 specifically protects the cardiac myocytes from ischemic damage when CT-1 is given not only prior to the ischemia, but also given at the time of reoxygenation. Current evidence suggests that CT-1 plays an important role in the regulation of the cardiovascular system.

Oncostatin M-enhanced vascular endothelial growth factor expression in human vascular smooth muscle cells involves PI3K-, p38 MAPK-, Erk1/2- and STAT1/STAT3-dependent pathways and is attenuated by interferon-γ

The pleiotropic cytokine oncostatin M (OSM), a member of the glycoprotein (gp)130 ligand family, plays a key role in inflammation and cardiovascular disease. As inflammation precedes and accompanies pathological angiogenesis, we investigated the effect of OSM and other gp130 ligands on vascular endothelial growth factor (VEGF) production in human vascular smooth muscle cells (SMC). Human coronary artery SMC (HCASMC) and human aortic SMC (HASMC) were treated with different gp130 ligands. VEGF protein was determined by ELISA. Specific mRNA was detected by RT-PCR. Western blotting was performed for signal transducers and activators of transcription1 (STAT1), STAT3, Akt and p38 mitogen-activated protein kinase (p38 MAPK). OSM mRNA and VEGF mRNA expression was analyzed in human carotid endaterectomy specimens from 15 patients. OSM increased VEGF production in both HCASMC and HASMC derived from different donors. OSM upregulated VEGF and OSM receptor-specific mRNA in these cells. STAT3 inhibitor WP1066, p38 MAPK inhibitors SB-202190 and BIRB 0796, extracellular signal-regulated kinase1/2 (Erk1/2) inhibitor U0126, and phosphatidylinositol 3-kinase (PI3K) inhibitors LY-294002 and PI-103 reduced OSM-induced VEGF synthesis. We found OSM expression in human atherosclerotic lesions where OSM mRNA correlated with VEGF mRNA expression. Interferon-γ (IFN-γ), but not IL-4 or IL-10, reduced OSM-induced VEGF production in vascular SMC. Our findings that OSM, which is present in human atherosclerotic lesions and correlates with VEGF expression, stimulates production of VEGF by human coronary artery and aortic SMC indicate that OSM could contribute to plaque angiogenesis and destabilization. IFN-γ reduced OSM-induced VEGF production by vascular SMC.

Vascular effects of cardiotrophin-1: a role in hypertension?

AIMS

To investigate cardiotrophin-1 (CT-1) effects and regulation in vascular smooth muscle cells (VSMCs) in vitro and in aortic tunica media ex vivo in normotensive Wistar rats and spontaneously hypertensive rats (SHRs).

METHODS AND RESULTS

CT-1 expression was quantified by real-time reverse-transcription PCR and western blotting. CT-1-activated intracellular pathways were assessed by western bloting analysis. Proliferation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ki67 immunodetection, and cell hypertrophy by planimetry. Extracellular matrix components were quantified by real-time reverse-transcription PCR and western blot, and metalloproteinases activities by zymography. VSMCs from Wistar rats and SHRs expressed spontaneously CT-1 at the mRNA and the protein level, with a two-fold more increase in SHRs. CT-1 phosphorylated p42/44 mitogen-activated protein kinase, p38 mitogen-activated protein kinase, Akt and Stat-3 in both strains. CT-1 stimulated VSMCs proliferation and hypertrophy in both strains, with an enhanced stimulation in SHRs. CT-1 increased the secretion of collagen type I and fibronectin in VSMCs and aortic tunica media of Wistar rats and SHRs, with greater magnitude in SHRs. In SHRs VSMCs in vitro and ex vivo, CT-1 increased the secretion of collagen type III and elastin and the expression of tissue inhibitors of metalloproteinases, without altering metalloproteinase activity. These effects were blocked by CT-1 receptor antibodies. Aldosterone treatment increased CT-1 expression in VSMCs and aortic tunica media from both strains, with a greater magnitude in SHRs.

CONCLUSION

CT-1 induces VSMCs proliferation, hypertrophy and extracellular matrix production, and is upregulated in hypertension and by aldosterone. CT-1 may represent a new target of vascular wall remodeling in hypertension.

Statins suppress interleukin-6-induced monocyte chemo-attractant protein-1 by inhibiting Janus kinase/signal transducers and activators of transcription pathways in human vascular endothelial cells

BACKGROUND AND PURPOSE

The mechanisms of anti-inflammatory actions of statins, 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase inhibitors, remain unclear. We investigated the effects of statins on interleukin (IL)-6-induced monocyte chemo-attractant protein (MCP)-1 expression and monocyte chemotaxis.

EXPERIMENTAL APPROACH

Cultures of human aortic endothelial cells (HAECs) were stimulated with IL-6 in the absence and presence of statins. Gene expression and protein secretion of MCP-1, phosphorylation of Janus kinase (JAK) and the signal transducers and activators of transcription (STAT) pathway, and human monocyte migration were examined.

KEY RESULTS

IL-6 plus its soluble receptor sIL-6R (IL-6/sIL-6R) promoted THP-1 monocyte migration, and increased gene expression and protein secretion of MCP-1, more than IL-6 alone or sIL-6R alone. Various statins inhibited IL-6/sIL-6R-promoted monocyte migration and MCP-1 expression in HAECs. Co-incubation of mevalonate and geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate, reversed the inhibitory effects of statins on MCP-1 expression. Geranylgeranyl transferase inhibitor, but not farnesyl transferase inhibitor, suppressed IL-6/sIL-6R-stimulated MCP-1 expression. IL-6/sIL-6R rapidly phosphorylated JAK1, JAK2, TYK2, STAT1 and STAT3, which were inhibited by statins. Transfection of STAT3 small interfering RNA (siRNA), but not STAT1 siRNA, attenuated the ability of IL-6/sIL-6R to enhance THP-1 monocyte migration. In addition, statins blocked IL-6/sIL-6R-induced translocation of STAT3 to the nucleus.

CONCLUSIONS AND IMPLICATIONS

Statins suppressed IL-6/sIL-6R-induced monocyte chemotaxis and MCP-1 expression in HAECs by inhibiting JAK/STAT signalling cascades, explaining why statins have anti-inflammatory properties beyond cholesterol reduction.

Interaction of vascular smooth muscle cells and monocytes by soluble factors synergistically enhances IL-6 and MCP-1 production

Inflammatory mechanisms contribute to atherogenesis. Monocyte chemoattractant protein (MCP)-1 and IL-6 are potent mediators of inflammation. Both contribute to early atherogenesis by luring monocytes and regulating cell functions in the vessel wall. MCP-1 and IL-6 production resulting from the interaction of invading monocytes with local vessel wall cells may accelerate atherosclerosis. We investigated the influence of the interaction of human vascular smooth muscle cells (SMCs) with human mononuclear cells (MNCs) or monocytes on IL-6 and MCP-1 production in a coculture model. Interaction synergistically enhanced IL-6 and MCP-1 production (up to 30- and 10-fold, respectively) compared with separately cultured cells. This enhancement was mediated by CD14-positive monocytes. It was dependent on the SMC-to-MNC/monocyte ratio, and as few as 0.2 monocytes/SMC induced the synergism. Synergistic IL-6 production was observed at the protein, mRNA, and functional level. It was mediated by soluble factors, and simultaneous inhibition of IL-1, TNF-alpha, and IL-6 completely blocked the synergism. IL-1, TNF-alpha, and IL-6 were present in the cultures. Blockade of the synergism by soluble glycoprotein 130Fc/soluble IL-6 receptor, as well as the induction of synergistic IL-6 production by costimulation of SMCs with IL-1, TNF-alpha, and hyper-IL-6, suggested the involvement of IL-6 trans-signaling. The contribution of IL-6 was consistent with enhanced STAT3 phosphorylation. The present data suggest that SMC/monocyte interactions may augment the proinflammatory status in the tissue, contributing to the acceleration of early atherogenesis.

Cardiotrophin-1. Review

BACKGROUND

Cardiotrophin-1 is newly discovered chemokin with a lot of functions. Aim of our work was to describe most important of them.

METHODS

systematically scan of available scientific resources.

RESULTS

Cardiotrophin-1 stimulates the proliferation of cardiomyocytes. Cardiotrophin-1 expression and plasma values are elevated in individuals with heart failure and have high diagnostic efficacy for the heart failure. Plasma values are also an independent prognostic factor. Preliminary findings suggest that the determination of plasma cardiotrophin-1 may be useful for the follow-up of hypertensive heart disease in routine clinical practice. Cardiotrophin-1 also plays an important cardioprotective effect on myocardial damage, is a potent regulator of signaling in adipocytes in vitro and in vivo and potentiates the elevation the acute-phase proteins. Cardiotrophin-1 may play also an important protective role in other organ systems (such as hematopoietic, neuronal, developmental).

CONCLUSION

Cardiotrophin is a newly discovered chemokin with a lot of system effects and is stable in system circulation hence permitting its development in the routine clinical investigation.