Endothelial Monocyte-activating polypeptide-II Research Articles

The effect of eight weeks of high-intensity interval training on the expression of mir-126, EMAP-II, and levels of TGF-β in the heart tissue of young rats with type 2 diabetes

Background and aims: Diabetes affects some cardiac angiogenic and antiangiogenic markers. Thus, the aim of this study was to investigate the effect of eight weeks of high-intensity interval training (HIIT) on mir-126, endothelial monocyte-activating polypeptide II (EMAP-II), and transforming growth factor beta (TGF-β) in young rats with type 2 diabetes (T2D). Methods: The statistical population of this experimental study included young rats (8 weeks old) with T2D. In this research, 24 young rats (8 weeks old) were divided into healthy+HIIT, diabetic+HIIT, and healthy control groups. The enzyme-linked immunosorbent assay method was used to measure TGF-β and the real-time polymerase chain reaction for mir-126 and EMAP-II. A one-way analysis of variance and the least significant difference post hoc test were used to compare the two groups. Results: The results showed diabetes+HIIT and healthy+HIIT had more mir-126 compared to healthy control (P=0.001). Healthy+HIIT, in comparison to diabetes+HIIT, had higher mir-126 expression (P=0.001). In addition, diabetes+HIIT, compared to the healthy control, had a higher EMAP-II expression (P=0.006). On the other hand, healthy+HIIT had lower EMAP-II in comparison to healthy control (P=0.001). Healthy+HIIT had a lower EMAP-II compared to diabetes+HIIT (P=0.001). Diabetes+HIIT, in comparison to the healthy control, had higher TGF-β levels (P=0.005). However, healthy+HIIT, compared to healthy control, had a lower expression of TGF-β (P=0.001). Finally, the healthy+HIIT groups, compared to the diabetes+HIIT group, had a lower TGF-β expression (P=0.001). Conclusion: Interval exercise could increase angiogenesis in diabetic samples through the increase of mir-126 and the reduction of TGF-β1 and EMAP-II.

Impacts of age, diabetes, and hypertension on serum endothelial monocyte-activating polypeptide-II after prolonged work in the heat.

With rising temperature extremes, older workers are becoming increasingly vulnerable to heat-related injuries because of age- and disease-associated decrements in thermoregulatory function. Endothelial monocyte-activating polypeptide-II (EMAP-II) is a proinflammatory cytokine that has not yet been well-characterized during heat stress, and which may mediate the inflammatory response to high levels of physiological strain. We evaluated serum EMAP-II concentrations before and after 180 min of moderate-intensity work (200 W/m2 ) in temperate (wet-bulb globe temperature [WBGT] 16°C) and hot (WBGT 32°C) environments in heat-unacclimatized, healthy young (n = 13; mean [SD]; 22 [3] years) and older men (n = 12; 59 [4] years), and unacclimatized older men with hypertension (HTN) (n = 10; 60 [4] years) or type 2 diabetes (T2D) (n = 9; 60 [5] years). Core temperature and heart rate were measured continuously. In the hot environment, work tolerance time was lower in older men with HTN and T2D compared to healthy older men (both p < 0.049). While core temperature and heart rate reserve increased significantly (p < 0.001), they did not differ across groups. End-exercise serum EMAP-II concentrations were higher in young men relative to their older counterparts due to higher baseline levels (both p ≤ 0.02). Elevations in serum EMAP-II concentrations were similar between healthy older men and older men with HTN, while serum EMAP-II concentrations did not change in older men with T2D following prolonged work in the heat. Serum EMAP-II concentrations increasedfollowing prolonged moderate-intensity work in the heat and this response is influenced by age and the presence of HTN or T2D.

Endothelin-1 gene polymorphism (G8002A) and endothelial monocyte-activating polypeptide II: Role in vascular dysfunction in pediatric patients with β-thalassemia major.

Endothelin-1 (ET-1), a potent endogenous vasoconstrictor, stimulates production of reactive oxygen species. Endothelial monocyte-activating polypeptide-II (EMAP-II) is a multifunctional polypeptide. To assess ET-1 gene polymorphism (G8002A) in pediatric patients with β-thalassemia major (β-TM) as a potential genetic marker for vascular dysfunction and its possible relation to EMAP II, oxidative stress and vascular complications. β-TM patients (n=95) without symptomatic cardiac or renal disease were compared with 95 healthy controls. Markers of hemolysis, serum ferritin, urinary albumin-to-creatinine ratio, serum EMAP II, malondialdehyde (MDA) and antioxidant enzymes; superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione reductase and catalase were measured. ET-1 gene polymorphism (G8002A) was determined using polymerase chain reaction‑restriction fragment length polymorphism. β-TM patients had significantly higher EMAP II than healthy controls. EMAP II was significantly higher among patients with cardiac disease, pulmonary hypertension (PH) risk, nephropathy, poor compliance to therapy and ferritin≥2500μg/L. There were significant correlations between EMAP II and transfusion index, LDH, ferritin and oxidative stress markers. The AA genotype of ET-1 gene polymorphism (G8002A) was significantly higher among β-TM patients than controls. The number of patients with cardiac disease, PH risk or nephropathy was significantly higher among AA genotype compared with GG and GA genotypes. Lactate dehydrogenase (LDH), serum ferritin, EMAP II, MDA, SOD and GPx were significantly higher in AA genotype. ET-1 gene polymorphism (G8002A) could be a possible genetic marker for prediction of increased susceptibility to cardiopulmonary and renal complications among pediatric patients with β-TM.

Endothelial Monocyte-Activating Polypeptide-II Is an Indicator of Severity and Mortality in COVID-19 Patients.

Data for predicting the severity and mortality of coronavirus disease 2019 (COVID-19) are limited, and investigations are ongoing. Endothelial monocyte-activating protein II (EMAP-II) is a multifunctional polypeptide with pro-inflammatory properties. EMAP-II is a significant pathogenic component in chronic inflammatory lung diseases and lung injury. In this study, we aimed to assess the potential utility of EMAP-II as a predictor of COVID-19 severity and mortality. This study included 20 healthy volunteers and 60 verified COVID-19 patients. Nasopharyngeal samples from COVID-19-positive subjects and normal volunteers were collected at admission. The nasopharyngeal samples were subjected to EMAP-II real-time polymerase chain reaction (RT-PCR). EMAP-II RNA was not detected in nasopharyngeal swabs of normal controls and mild to asymptomatic COVID-19 patients and was only detectable in severe COVID-19 patients. EMAP-II critical threshold (Ct) was positively associated with lymphocyte percentages and oxygen saturation (p < 0.001) while being negatively associated with age (p = 0.041), serum CRP, ferritin, and D-dimer levels (p < 0.001). EMAP-II Ct cutoff ≤34 predicted a worse outcome in COVID-19 illness, with a sensitivity and specificity of 100%. Our study suggests that EMAP-II could be considered a potential biomarker of COVID-19 severity. EMAP-II can predict the fatal outcome in COVID-19 patients.

PROGNOSTICATION OF COMPLICATED COURSE OF ACUTE MYOCARDIAL INFARCTION WITH CONCOMITANT TYPE 2 DIABETES MELLITUS BASED ON USE OF ENDOTHELIAL MONOCYTE ACTIVATING POLYPEPTIDE-ІІ

The aim: To determine the prognostic value of endothelial monocytic peptide ІІ in the course of AMI (acute myocardial infarction) in combination with type 2 diabetes mellitus (DM) Materials and methods: The study involved 120 patients divided in 2 groups: Group 1 – patients with acute myocardial infarction (AMI) with concomitant type 2 DM (n=69); Group 2 – patients with AMI without concomitant type 2 DM (n=51). Control group was composed with 20 almost healthy persons. Results: It was determined that in patients with AMI in combination with type 2 diabetes, the level of endothelial monocyte-activating polypeptide II (EMAP-II) was 1.65 times higher than in patients without concomitant type 2 DM (p &lt;0.05). The patients with AMI and type 2 DM who were included in the group of the 3rd tertile according to level of EMAR-II had the complicated course compared to patients in the groups of the 1st and 2nd tertiles. Q-positive AMI was found in 100% of patients who belonged to the group of the 3rd tertile; recurrence of AMI occurred only in patients whose EMAR-II index was included in the 3rd tertile. Conclusions: According to the results of endothelial function analysis with usу ща the marker of EMAP-II endothelial dysfunction in patients with AMI and concomitant type 2 DM, the increased level of this parameter was characteristic of pronounced violation of dilatation properties of the vascular wall and of the other indicators of complicated comorbid conditions.

PROGRESSION OF DIABETIC NON-PROLIFERATIVE RETINOPATHY IN TYPE 2 DIABETES MELLITUS: THE CONNECTION WITH THE BLOOD ENDOTHELIAL MONOCYTE-ACTIVATING POLYPEPTIDE-II LEVEL

Relevance. The numerous pro-inflammatory and antiangiogenic properties of endothelial monocyte-activating polypeptide-II (EMAP-II) suggest its possible role in the onset and progression of diabetic non-proliferative retinopathy (DNPR) in type 2 diabetes mellitus (T2DM).&#x0D; Objective – is to determine the blood EMAP-II in the DM2 patients and to establish its connection with the progression of DNPR.&#x0D; Material and methods. We examined 91 patients with DM2 (182 eyes), who were divided into groups: 1st – there was no DNPR in both eyes and 2nd – there was no retinopathy in one eye, and isolated vascular anomalies were noted in the other (ETDRS level 14, 15). The control group included 25 patients of the corresponding age and gender. The patients were re-examined after 1 year. The level of EMAP-II was determined by the enzyme immunoassay in blood plasma once at the beginning of the study. Statistical packages MedStat and MedCalc v.15.1 (MedCalc Software bvba) were used for statistical research.&#x0D; Results. The analysis of clinical and laboratory parameters showed that the initial manifestations of diabetic retinal lesions were manifested in 27.5% of patients after 7.16±1.11 years and were accompanied by greater glycemia. The level of EMAP-II in DM2 was many times higher than in the control, which depended on the presence of diabetic vascular changes in the retina: in patients without changes in the retina (group 1) – by 3.7 times, and in patients with initial vascular anomalies (group 2) – 5.2 times (p&lt;0.001). The level of EMAP-II at the beginning of the study was associated with the progression of diabetic changes in the retina after 1 year – with their presence, it was 1.5 times higher than without them (p&lt;0.001). Stratification by stage of DNPR after 1 year also showed the dependence of the severity of diabetic changes in the retina on the initial level of EMAP-II: in the presence of single vascular anomalies and initial DNPR, it was increased by 3-4 times, while with moderate DNPR – 5.9 times (p&lt;0.001 for all comparisons).&#x0D; Conclusion. Thus, a significant increase in the level of EMAP-II in T2DM was established, and the dependence of the initial diabetic changes in the retina and the degree of their progression in 1 year after the increasing of the blood EMAP-II level.

Endothelial Monocyte-activating Polypeptide-II in Egyptian Sickle Patients

Endothelial Monocyte-activating Polypeptide-II in Egyptian Sickle Patients

HIV-Nef Protein Persists in the Lungs of Aviremic Patients with HIV and Induces Endothelial Cell Death.

It remains a mystery why HIV-associated end-organ pathologies persist in the era of combined antiretroviral therapy (ART). One possible mechanism is the continued production of HIV-encoded proteins in latently HIV-infected T cells and macrophages. The proapoptotic protein HIV-Nef persists in the blood of ART-treated patients within extracellular vesicles (EVs) and peripheral blood mononuclear cells. Here we demonstrate that HIV-Nef is present in cells and EVs isolated from BAL of patients on ART. We hypothesize that HIV-Nef persistence in the lung induces endothelial apoptosis leading to endothelial dysfunction and further pulmonary vascular pathologies. The presence of HIV-Nef in patients with HIV correlates with the surface expression of the proapoptotic endothelial-monocyte-activating polypeptide II (EMAPII), which was implicated in progression of pulmonary emphysema via mechanisms involving endothelial cell death. HIV-Nef protein induces EMAPII surface expression in human embryonic kidney 293T cells, T cells, and human and mouse lung endothelial cells. HIV-Nef packages itself into EVs and increases the amount of EVs secreted from Nef-expressing T cells and Nef-transfected human embryonic kidney 293T cells. EVs from BAL of HIV+ patients and Nef-transfected cells induce apoptosis in lung microvascular endothelial cells by upregulating EMAPII surface expression in a PAK2-dependent fashion. Transgenic expression of HIV-Nef in vascular endothelial-cadherin+ endothelial cells leads to lung rarefaction, characterized by reduced alveoli and overall increase in lung inspiratory capacity. These changes occur concomitantly with lung endothelial cell apoptosis. Together, these data suggest that HIV-Nef induces endothelial cell apoptosis via an EMAPII-dependent mechanism that is sufficient to cause pulmonary vascular pathologies even in the absence of inflammation.

Endothelial Monocyte-Activating Polypeptide-II Induces BNIP3-Mediated Mitophagy to Enhance Temozolomide Cytotoxicity of Glioma Stem Cells via Down-Regulating MiR-24-3p.

Preliminary studies have shown that endothelial-monocyte-activating polypeptide-II (EMAP-II) and temozolomide (TMZ) alone can exert cytotoxic effects on glioma cells. This study explored whether EMAP-II can enhance the cytotoxic effects of TMZ on glioma stem cells (GSCs) and the possible mechanisms associated with Bcl-2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3)-mediated mitophagy facilitated by miR-24-3p regulation. The combination of TMZ and EMAP-II significantly inhibited GSCs viability, migration, and invasion, resulting in upregulation of the autophagy biomarker microtubule-associated protein one light chain 3 (LC3)-II/I but down-regulation of the proteins P62, TOMM 20 and CYPD, changes indicative of the occurrence of mitophagy. BNIP3 expression increased significantly in GSCs after treatment with the combination of TMZ and EMAP-II. BNIP3 overexpression strengthened the cytotoxic effects of EMAP-II and TMZ by inducing mitophagy. The combination of EMAP-II and TMZ decreased the expression of miR-24-3p, whose target gene was BNIP3. MiR-24-3p inhibited mitophagy and promoted proliferation, migration and invasion by down-regulating BNIP3 in GSCs. Furthermore, nude mice subjected to miR-24-3p silencing combined with EMAP-II and TMZ treatment displayed the smallest tumors and the longest survival rate. According to the above results, we concluded that EMAP-II enhanced the cytotoxic effects of TMZ on GSCs' proliferation, migration and invasion both in vitro and in vivo.

MiR-429 Regulated by Endothelial Monocyte Activating Polypeptide-II (EMAP-II) Influences Blood-Tumor Barrier Permeability by Inhibiting the Expressions of ZO-1, Occludin and Claudin-5.

The blood-tumor barrier (BTB) hinders delivery of chemotherapeutic drugs to tumors in the brain; previous studies have shown that the BTB can be selectively opened by endothelial monocyte activating polypeptide-II (EMAP-II), but the specific mechanism involved remains elusive. In this study, we found that microRNA-429 (miR-429) expression in glioma vascular endothelial cells (GECs) was far lower than in human brain microvascular endothelial cells (ECs). miR-429 had lower expression in GECs and glioma tissues compared to ECs or normal tissues of the brain. Furthermore, miR-429 had lower expression in high grade glioma (HGG) than in low grade glioma (LGG). In in vitro BTB models, we also found that EMAP-II significantly increased BTB permeability, decreased expression of ZO-1, occludin and claudin-5 in GECs, in a time- and dose-dependent manner. EMAP-II greatly increased miR-429 expression in GECs of the BTB models in vitro. Overexpression of miR-429 in GECs significantly decreased the transepithelial electric resistance (TEER) values in BTB models, and led to enhanced horseradish peroxidase (HRP) flux. Overexpression of miR-429 in GECs significantly decreased the expression of tight junction (TJ)-associated proteins (ZO-1, occludin and claudin-5), and decreased the distribution continuity. Silencing of miR-429 in GECs increased the expression of TJ-associated proteins and the distribution continuity. The dual-luciferase reporter assay revealed that ZO-1 and occludin were target genes of miR-429, and we demonstrated that miR-429 overexpression markedly down-regulated protein expression of p70S6K, as well as its phosphorylation levels. The dual-luciferase reporter assay also showed that p70S6K was a target gene of miR-429; miR-429 overexpression down-regulated expression and phosphorylation levels of p70S6K, and also decreased phosphorylation levels of S6 and increased BTB permeability. Conversely, silencing of miR-429 increased the expression and phosphorylation levels of p70S6K, and increased phosphorylation levels of S6, while decreasing BTB permeability. In conclusion, the results indicated that EMAP-II caused an increase in miR-429 expression that directly targeted TJ-associated proteins, which were negatively regulated; on the other hand, miR-429 down-regulated the expression of TJ-associated proteins by targeting p70S6K, also negatively regulated. As a result, the BTB permeability increased.

The Role of miR-330-3p/PKC-α Signaling Pathway in Low-Dose Endothelial-Monocyte Activating Polypeptide-II Increasing the Permeability of Blood-Tumor Barrier.

This study was performed to determine whether EMAP II increases the permeability of the blood-tumor barrier (BTB) by affecting the expression of miR-330-3p as well as its possible mechanisms. We determined the over-expression of miR-330-3p in glioma microvascular endothelial cells (GECs) by Real-time PCR. Endothelial monocyte-activating polypeptide-II (EMAP-II) significantly decreased the expression of miR-330-3p in GECs. Pre-miR-330-3p markedly decreased the permeability of BTB and increased the expression of tight junction (TJ) related proteins ZO-1, occludin and claudin-5, however, anti-miR-330-3p had the opposite effects. Anti-miR-330-3p could enhance the effect of EMAP-II on increasing the permeability of BTB, however, pre-miR-330-3p partly reversed the effect of EMAP-II on that. Similarly, anti-miR-330-3p improved the effects of EMAP-II on increasing the expression levels of PKC-α and p-PKC-α in GECs and pre-miR-330-3p partly reversed the effects. MiR-330-3p could target bind to the 3′UTR of PKC-α. The results of in vivo experiments were similar to those of in vitro experiments. These suggested that EMAP-II could increase the permeability of BTB through inhibiting miR-330-3p which target negative regulation of PKC-α. Pre-miR-330-3p and PKC-α inhibitor decreased the BTB permeability and up-regulated the expression levels of ZO-1, occludin and claudin-5 while anti-miR-330-3p and PKC-α activator brought the reverse effects. Compared with EMAP-II, anti-miR-330-3p and PKC-α activator alone, the combination of the three combinations significantly increased the BTB permeability. EMAP-II combined with anti-miR-330-3p and PKCα activator could enhance the DOX’s effects on inhibiting the cell viabilities and increasing the apoptosis of U87 glioma cells. Our studies suggest that low-dose EMAP-II up-regulates the expression of PKC-α and increases the activity of PKC-α by inhibiting the expression of miR-330-3p, reduces the expression of ZO-1, occludin and claudin-5, and thereby increasing the permeability of BTB. The results can provide a new strategy for the comprehensive treatment of glioma.

Ендотеліальний моноцитактивуючий фактор II поліпшує серцеву функцію та розслаблення судин при цукровому діабеті 1-го типу

Ендотеліальний моноцитактивуючий фактор II поліпшує серцеву функцію та розслаблення судин при цукровому діабеті 1-го типу

Combination of Endothelial-Monocyte-Activating Polypeptide-II with Temozolomide Suppress Malignant Biological Behaviors of Human Glioblastoma Stem Cells via miR-590-3p/MACC1 Inhibiting PI3K/AKT/mTOR Signal Pathway.

This study aims to investigate the effect of Endothelial-Monocyte-Activating Polypeptide-II (EMAP-II) combined with temozolomide (TMZ) upon glioblastoma stem cells (GSCs) and its possible molecular mechanisms. In this study, combination of EMAP-II with TMZ inhibited cell viability, migration and invasion in GSCs, and autophagy inhibitor 3-methyl adenine (3-MA) and chloroquine (CQ) partly reverse the anti-proliferative effect of the combination treatment. Autophagic vacuoles were formed in GSCs after the combination therapy, accompanied with the up-regulation of LC3-II and Beclin-1 as well as the down-regulation of p62/SQSTM1. Further, miR-590-3p was up-regulated and Metastasis-associated in colon cancer 1 (MACC1) was down-regulated by the combination treatment in GSCs; MiR-590-3p overexpression and MACC1 knockdown up-regulated LC3-II and Beclin-1 as well as down-regulated p62/SQSTM1 in GSCs; MACC1 was identified as a direct target of miR-590-3p, mediating the effects of miR-590-3p in the combination treatment. Furthermore, the combination treatment and MACC1 knockdown decreased p-PI3K, p-Akt, p-mTOR, p-S6 and p-4EBP in GSCs; PI3K/Akt agonist insulin-like growth factor-1(IGF-1) partly blocked the effect of the combination treatment. Moreover, in vivo xenograft models, the mice given stable overexpressed miR-590-3p cells and treated with EMAP-II and TMZ had the smallest tumor sizes, besides, miR-590-3p + EMAP-II + TMZ up-regulated the expression level of miR-590-3p, LC3-II and Beclin-1 as well as down-regulated p62/SQSTM1. In conclusion, these results elucidated anovel molecular mechanism of EMAP-II in combination with TMZ suppressed malignant biological behaviors of GSCs via miR-590-3p/MACC1 inhibiting PI3K/AKT/mTOR signaling pathway, and might provide potential therapeutic approaches for human GSCs.

An elevated serum level of endothelial monocyte activating polypeptide-II in patients with arterial hypertension with and without type 2 diabetes and obesity

Objectives: To assess serum levels of endothelial monocyte activating polypeptide-II (EMAP-II) in patients with arterial hypertension with and without type 2 diabetes mellitus and obesity.Materials and methods: We examined 41 hypertensive patients with type 2 diabetes, 18 obese hypertensive patients without diabetes, 9 non-obese hypertensive patients without diabetes, and 18 healthy control subjects.Results: We found an increased serum level of EMAP-II in hypertensive patients with type 2 diabetes compared to controls (4.86±2.3 and 1.08±0.53 ng/ml respectively, р0.01), in hypertensive patients with obesity (2.92±1.42 ng/ml) compared to controls, and in non-obese hypertensive patients (2.02±0.33 ng/ml) compared to controls. Also, the levels of EMAP-II significantly correlated with HbA1c, blood glucose, serum insulin levels, HOMA, lipids, and body mass index (р0.01).Conclusions: The revealed changes could reflect an endothelial dysfunction mostly pronounced in patients with arterial hypertension, type 2 diabetes mellitus and obesity. Hyperglycemia, dyslipidemia, insulin resistance, obesity appear to be significant contributing factors leading to the elevation of EMAP-II.

Low-Dose Endothelial-Monocyte-Activating Polypeptide-II Induced Autophagy by Down-Regulating miR-20a in U-87 and U-251 Glioma Cells.

Preliminary studies have shown that endothelial-monocyte-activating polypeptide-II (EMAP-II) induces autophagy and inhibits the viability of glioma cells via an unknown molecular mechanism. This study explored the possible mechanisms associated with EMAP-II-induced autophagy in glioma cells by regulation of the expression of microRNA-20a (miR-20a). EMAP-II effectively inhibited the viability, migration and invasion of human U-87 and U-251 glioma cells. EMAP-II also up-regulated the expression level of autophagy biomarker microtubule-associated protein one light chain 3 (LC3)-II/I, autophagy related gene ATG7 and ATG5, but down-regulated autophagy substrate P62/SQSTM1 protein expression. The expression levels of miR-20a decreased significantly after U-87 and U-251 cells were treated with EMAP-II. MiR-20a overexpression partly reversed the EMAP-II-induced up-regulation of LC3-II/I and down-regulation of P62/SQSTM1. MiR-20a had a negative regulatory effect on the expression of the proteins ATG7 and ATG5; which were also targets of miR-20a, as detected by a dual-luciferase reporter assay. In addition, both EMAP-II and miR-20a inhibition significantly reduced the viability, migration and invasion of U-87 and U-251 cells, and their combination showed a synergistic effect. Furthermore, nude mice carrying silencing-expressed miR-20a combined with EMAP-II treatment produced the smallest tumors and the highest survival. In summary, low-dose EMAP-II increased expression levels of ATG5 and ATG7 via down-regulation of the expression of miR-20a. This activated the autophagy pathway, thereby significantly inhibiting the viability, migration and invasion of U-87 and U-251 glioma cells. The combined treatment of EMAP-II with a miR-20a inhibitor showed a synergistic effect against glioma.

Serum Levels of Endothelial Monocyte-Activating Polypeptide-II in Hepatitis C Patients

Objectives: Endothelial monocyte-activating polypeptide-II (EMAP-II) is a cytokine with pro-inflammatory and immune-suppressive properties. The goal of this study was to assess serum EMAP-II in treated and untreated Hepatitis C virus (HCV) patients. Furthermore, we determined the relationship between serum EMAP-II levels with the clinic pathological and laboratory parameters in patients with HCV. Methods: 25 control patients (Group I), 25 treated HCV patients (Group II) and 25 newly diagnosed, untreated patients with HCV (Group III) were included in this study. Serum EMAP-II levels were detected by Enzyme linked immunosorbent assay (ELISA), and HCV RNA was assessed by real time-PCR (RT-PCR). The results were evaluated against clinical and laboratory data. Results: Serum EMAP-II levels were significantly elevated in newly diagnosed, untreated HCV patients compared to treated HCV and control patients (p<0.001). We found that serum EMAP-II levels correlated positively with HCV RNA in untreated HCV patients (p<0.001). While serum albumin and platelet count correlated negatively with serum EMAP-II levels (p<0.001), a positive correlation was observed between EMAP-II and serum bilirubin (p<0.001). Conclusions: Increased serum EMAP-II levels are present in newly diagnosed HCV patients compared to treated HCV and control patients, suggesting EMAP-II as a novel biomarker for HCV diagnosis.

Low-Dose Endothelial Monocyte-Activating Polypeptide-II Increases Blood-Tumor Barrier Permeability by Activating the RhoA/ROCK/PI3K Signaling Pathway.

Previous studies have demonstrated that low-dose endothelial monocyte-activating polypeptide-II (EMAP-II) can increase blood-tumor barrier (BTB) permeability via both paracellular and transcellular pathways. In addition, we revealed that the RhoA/Rho kinase (ROCK) signaling pathway is involved in EMAP-II-induced BTB opening. This study further investigated the exact mechanisms by which the RhoA/ROCK signaling pathway affects EMAP-II-induced BTB hyperpermeability. In an in vitro BTB model, low-dose EMAP-II significantly activated phosphatidylinositol-3-kinase (PI3K) in rat brain microvascular endothelial cells (RBMECs) at 0.75h. Pretreatment with RhoA inhibitor C3 exoenzyme or ROCK inhibitor Y-27632 completely blocked EMAP-II-induced activation of PI3K. PKC-α/β inhibitor GÖ6976 pretreatment caused no change in EMAP-II-induced activation of PI3K. Besides, pretreatment with LY294002, a specific inhibitor of PI3K, did not affect EMAP-II-induced activation of PKC-α/β. Furthermore, LY294002 pretreatment significantly diminished EMAP-II-induced changes in BTB permeability, phosphorylation of myosin light chain and cofilin, expression and distribution of tight junction-associated protein ZO-1, and actin cytoskeleton arrangement in RBMECs. In summary, this study demonstrates that low-dose EMAP-II can increase BTB permeability by activating the RhoA/ROCK/PI3K signaling pathway.

Low-Dose Endothelial Monocyte-Activating Polypeptide-II Induces Blood-Tumor Barrier Opening Via the cAMP/PKA/Rac1 Pathway.

Previous studies have demonstrated that low-dose endothelial monocyte-activating polypeptide-II (EMAP-II) induces blood-tumor barrier (BTB) hyperpermeability via both paracellular and transcellular pathways. In a recent study, we revealed that cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)-dependent signaling pathway is involved in EMAP-II-induced BTB hyperpermeability. This study further investigated the exact mechanisms through which the cAMP/PKA-dependent signaling pathway affects EMAP-II-induced BTB hyperpermeability. In an in vitro BTB model, low-dose EMAP-II (0.05 nM) induced a significant decrease in Rac1 activity in rat brain microvascular endothelial cells (RBMECs). Pretreatment with forskolin to elevate intracellular cAMP concentration completely blocked EMAP-II-induced inactivation of Rac1. Besides, pretreatment with 6Bnz-cAMP to activate PKA partially attenuated EMAP-II-induced Rac1 inactivation. Moreover, 6Bnz-cAMP pretreatment significantly diminished EMAP-II-induced changes in BTB permeability, myosin light chain (MLC) phosphorylation, expression and distribution of ZO-1, and actin cytoskeleton arrangement in RBMECs. These effects of 6Bnz-cAMP were completely blocked in the presence of NSC-23766 (the specific inhibitor of Rac1). In conclusion, this study demonstrates that low-dose EMAP-II induces BTB hyperpermeability via the cAMP/PKA/Rac1 signaling pathway.

Distribution and characterization of tumor-associated macrophages/microglia in rat C6 glioma

Immunity responses and immunotherapy are novel areas of research for the pathological development and treatment of glioma, the most common brain cancer. Characterization of the subpopulations of infiltrated immune cells may aid in our understanding of the tumor immune response and contribute to the identification of cellular targets for selective immunotherapy. Using a rat C6 glioma model, the present study observed a significant heterogeneity of active macrophages and microglia, including cluster of differentiation 8 (CD8)+, endothelial monocyte-activating polypeptide II (EMAPII)+ and ED1+ cells, mostly in the areas of compact tumor growth and inside or around the pannecrosis. Moreover, the CD8+ cells were similar to reactive ED1+ and EMAPII+ microglia/macrophages in morphology and distribution, but different from the W3/13+ T cells. These observations suggest that different subtypes of macrophages and microglia are involved in glioma development and thus, may be potential targets for immunotherapeutic antitumor strategies.

Roles of Serine/Threonine Phosphatases in Low-Dose Endothelial Monocyte-Activating Polypeptide-II-Induced Opening of Blood–Tumor Barrier

Previous studies have demonstrated that low-dose endothelial monocyte-activating polypeptide-II (EMAP-II) induces blood-tumor barrier (BTB) opening via RhoA/Rho kinase/PKC-α/β signaling pathway. In a recent study, we revealed that low-dose EMAP-II induced significant increases in expression levels of serine/threonine (Ser/Thr) phosphatase (PP)1 and 2A in rat brain microvascular endothelial cells (RBMECs) of BTB model. In addition, PKC-ζ/PP2A signaling pathway is involved in EMAP-II-induced BTB hyperpermeability. The present study further investigated the exact roles of PPs in this process. In an in vitro BTB model, low-dose EMAP-II (0.05nM) induced a significant increase in PP1 activity in RBMECs. There was an interaction between PKC-α/β and PP1 in RBMECs. Inhibition of PKC-α/β activity with GÖ6976 completely blocked EMAP-II-induced activation of PP1. Conversely, inhibition of PP1 activity with tautomycin had no effect on EMAP-II-induced PKC-α/β activation. Like GÖ6976, tautomycin significantly prevented EMAP-II-induced BTB hyperpermeability and MLC phosphorylation in RBMECs. Also, in this study, EMAP-II induced a marked redistribution of occludin and a significant dephosphorylation of occludin on Ser/Thr residues in RBMECs. Similar with GÖ6976 pretreatment, tautomycin pretreatment dramatically diminished EMAP-II-induced redistribution of occludin. Furthermore, pretreatment with tautomycin significantly inhibited EMAP-II-induced dephosphorylation of occludin on Ser residues. However, pretreatment with okadaic acid (an inhibitor of PP2A) significantly prevented changes in Ser-phosphorylated occludin induced by EMAP-II treatment. Collectively, this study demonstrates that low-dose EMAP-II increases BTB permeability via a RhoA/Rho kinase/PKC-α/β/PP1 signaling pathway and that PP1/PP2A-mediated Ser/Thr dephosphorylation of occludin plays an important role in EMAP-II-induced BTB hyperpermeability.