CD137 Signal Mediates Cardiac Ischemia-Reperfusion Injury by Regulating the Necrosis of Cardiomyocytes.

The injury of cardiomyocytes after ischemia-reperfusion is the main reason of cardiac dysfunction. Necrosis is one of the methods of programmed cell death and cardiomyocyte necrosis occurs in the process of reperfusion. The activation of CD137 signal is involved in various diseases. In vivo experiments proved that CD137-/- mice have less heart damage than wild-type mice after ischemia-reperfusion. In vitro experiments, we found that after inhibiting the CD137 signal, the degree of necrosis of HL-1 cells was reduced and it was caused by reducing the Ca2 + overload in the mitochondria, which caused the reduction of mPTP opening. Ca2 + overload in mitochondria induced by activation of CD137 signal was caused by increased Ca2 + released into mitochondria by activation of IP3R and increased MCU level. These results indicate that CD137 signaling aggravates cardiac ischemia-reperfusion injury by inducing myocardial cell necrosis.

Antithrombotic Therapy With Ticagrelor in Atrial Fibrillation Subjects After Percutaneous Coronary Intervention.

Background: Warfarin, along with aspirin and clopidogrel, has long been recommended for patients with atrial fibrillation (AF) who are undergoing percutaneous coronary intervention with a drug-eluting stent (PCI-DES). However, this triple therapy has been known to increase the risk of bleeding complications. Meanwhile, there is no evidence from prospective trials on the use of ticagrelor in a dual therapy. We here aimed to compare the antiplatelet drug ticagrelor as a dual antithrombotic agent to aspirin and clopidogrel in bleeding events. Methods: In this multicenter, active-controlled, open-label, randomized trial, patients with AF taking warfarin who had undergone PCI-DES were randomly assigned to the ticagrelor therapy group (Dual group) or the clopidogrel plus aspirin therapy group (Triple group). The primary and secondary endpoints were overall bleeding events and major bleeding events, respectively, according to the Thrombolysis in Myocardial Infarction (TIMI) criteria at 6 months. Cardiovascular events [re-PCI, surgical bypass, myocardial infarction (MI), heart failure, rehospitalization due to angina pectoris, stent thrombosis and death due to cardiovascular causes] at 6 months were also recorded. Results: A total of 296 patients from 12 medical centers in China were randomized after PCI-DES to either the Dual therapy group (n = 148) or the Triple group (n = 146) for 6 months. The overall incidence of bleeding events at 6 months was 36.49% in the Dual therapy group and 35.62% in the Triple group [hazard ratio, 0.930; 95% confidence interval (CI), 0.635 to 1.361; P = 0.7088]. The incidence of the secondary endpoint over 6 months was 4.73% in the Dual therapy group and 1.37% in the Triple group (hazard ratio, 0.273; 95% CI, 0.057 to 1.315; P = 0.1056). Cardiovascular event occurrence was also comparable in both groups at 6 months (18.24 vs. 16.44%; hazard ratio, 0.845; 95% CI, 0.488 to 1.465; P = 0.5484). Conclusions: The incidence of total bleeding events in AF patients treated with ticagrelor was comparable to that in patients treated with clopidogrel plus aspirin at 6 month; Meanwhile, the incidence of cardiovascular events were also comparable between the groups. Clinical Trial Registration: MANJUSRI, ClinicalTrials.gov# NCT02206815, 2014, August 1st.

Use of Inflammatory Biomarkers and Real-Time Cardiac Catheterisation to Evaluate the Left Ventricular Diastolic Function in Patients With Diastolic Heart Failure.

BACKGROUND: Interleukin (IL)-17 and its related cytokines have been shown to be involved in myocardial fibrosis and irreversible ventricular remodelling, which have predictive values in the development of left ventricular diastolic dysfunction (LVDD). This study aimed to assess the correlation between IL-17 and LVDD, and investigate the prognostic value of IL-17 among patients with normal left ventricular ejection fraction (LVEF). METHODS: A total of 120 patients with normal LVEF underwent left ventricular (LV) catheterisation for LV end-diastolic pressure (LVEDP) measurement and routine echocardiography. The follow-up period was 30 (18, 35) months. RESULTS: The levels of IL-17 and IL-6 from the systemic blood were significantly increased in non-heart failure (HF) patients with LVDD (p<0.001). Receiver operating characteristic (ROC) revealed that the combination of IL-17 and IL-6 showed the highest diagnostic accuracy in predicting LVDD (AUC, 0.890; 95% CI, 0.835-0.945; p<0.001), and the cut-off value was 41.5 pg/mL. On logistic regression analysis, the increment of the combination of IL-17 and IL-6 was an independent predictor for the prognosis of LVDD (odds ratio, 1.25; 95% CI, 1.01-1.12; p<0.05). According to the cut-off value of the combination of IL-17 and IL-6, the patients with lower levels of IL-17 and IL-6 (<41.5 pg/mL group) had a better prognosis. The increased levels of IL17 and IL-6 were significantly correlated with the levels of fibrotic parameters. CONCLUSIONS: Assessment of LVDD by measuring the combination of IL-17 and IL-6 might provide valuable prognostic significance for non-HF patients with LVDD.

OxLDL/ß2GPI/anti­ß2GPI Ab complex induces inflammatory activation via the TLR4/NF­κB pathway in HUVECs.

Patients with antiphospholipid syndrome have been identified to have higher incidence rates of atherosclerosis (AS) due to the elevated levels of anti­ß2­glycoprotein I (ß2GPI) antibody (Ab). Our previous studies revealed that the anti­ß2GPI Ab formed a stable oxidized low­density lipoprotein (oxLDL)/ß2GPI/anti­ß2GPI Ab complex, which accelerated AS development by promoting the accumulation of lipids in macrophages and vascular smooth muscle cell. However, the effects of the complex on endothelial cells, which drive the initiation and development of AS, remain unknown. Thus, the present study aimed to determine the proinflammatory roles of the oxLDL/ß2GPI/anti­ß2GPI Ab complex in human umbilical vein endothelial cells (HUVECs) in an attempt to determine the underlying mechanism. Reverse transcription­quantitative PCR, enzymy­linked immunosorbent assay, western blotting and immunofluorescence staining were performed to detect the expressions of inflammation related factors and adhesion molecules. Monocyte­binding assay was used to investigate the effects of oxLDL/ß2GPI/anti­ß2GPI Ab complex on monocyte adhesion to endothelial cells. The results demonstrated that the oxLDL/ß2GPI/anti­ß2GPI Ab complex upregulated the expression of Toll­like receptor (TLR)4 and the levels of NF­κB phosphorylation in HUVECs, and subsequently enhanced the expression levels of inflammatory cytokines, including TNF­α, IL­1ß and IL­6, as well as those of adhesion molecules, such as intercellular adhesion molecule 1 and vascular adhesion molecule 1. In addition, the complex facilitated the recruitment of monocytes by promoting the secretion of monocyte chemotactic protein 1 in HUVECs. Notably, the described effects of the oxLDL/ß2GPI/anti­ß2GPI Ab complex in HUVECs were abolished by either TLR4 or NF­κB blockade. In conclusion, these findings suggested that the oxLDL/ß2GPI/anti­ß2GPI Ab complex may induce a hyper­inflammatory state in endothelial cells by promoting the secretion of proinflammatory cytokines and monocyte recruitment, which was discovered to be largely dependent on the TLR4/NK­κB signaling pathway.

Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway.

Combination of antiangiogenesis and immunotherapy may be an effective strategy for treatment of solid tumors. Our previous work reported that activation of CD137 signaling promotes intraplaque angiogenesis. A number of studies have demonstrated that vascular endothelial growth factor receptor 2 (VEGFR2) is a key target for angiogenesis. However, it is unknown whether CD137-mediated angiogenesis is related to VEGFR2. In this study, we investigated the effect of CD137 on the VEGFR2 expression and explored the underlying mechanisms of CD137-mediated angiogenesis. Knock-out of CD137 in ApoE-/- mice significantly decreased neovessel density in atherosclerotic plaques. CD137 silencing or inhibition attenuated endothelial cell (ECs) proliferation, migration, and tube formation. We found activation of CD137 signaling for increased VEGFR2 transcription and translation steadily. Moreover, CD137 signaling activated phosphorylated VEGFR2 (Tyr1175) and the downstream Akt/eNOS pathway, whereas neutralizing CD137 signaling weakened the activation of VEGFR2 and the downstream Akt/eNOS pathway. The aortic ring assay further demonstrated that CD137 signaling promoted ECc sprouting. Inhibition of VEGFR2 by siRNA or XL184 (cabozantinib) and inhibition of downstream signaling by LY294002 (inhibits AKT activation) and L-NAME (eNOS inhibitor) remarkably abolished proangiogenic effects of CD137 signaling both in vitro and ex vivo. In addition, the condition medium from CD137-activated ECs and vascular endothelial growth factor A (VEGFA) had similar effects on ECs that expressed high VEGFR2. Additionally, activating CD137 signaling promoted endothelial secretion of VEGFA, while blocking CD137 signaling attenuated VEGFA secretion. In conclusion, activation of CD137 signaling promoted sprouting angiogenesis by increased VEGFA secretion and the VEGFR2/Akt/eNOS pathway. These findings provide a basis for stabilizing intraplaque angiogenesis through VEGFR2 intervatioin, as well as cancer treatment via combination of CD137 agonists and specific VEGFR2 inhibitors.

Serial assessment of focal myocardial function after percutaneous coronary intervention for ST-elevation myocardial infarction: Value of layer-specific speckle tracking echocardiography.

BACKGROUND: Ischemia-reperfusion injury (IRI) frequently follows successful PCI for STEMI and is recognized by multiple modalities. Multilayer speckle tracking echocardiography (STE) has the potential of detecting myocardial dysfunction in different myocardial layers. Our objective was to describe the changes in layer-specific myocardial function over the 24 hours after successful PCI for ST-elevation myocardial infarction (STEMI). METHODS: Patients (n = 120) with STEMI and no prior myocardial infarction underwent echocardiography prior to PCI, immediately after and at 3- and 24-hours post-PCI. Worsening focal dysfunction (WFD) was defined as an immediate reduction, compared to the pre-PCI value, in the amplitude of endo-myocardial longitudinal strain (endo-MLS) within the infarction territory. RESULTS: Patients with WFD (52%) had further reductions in endo-MLS, mid-MLS, and epi-MLS in the infarction region immediately post-PCI; at 3 hours strain began to improve and continued to improve at 24 hours. Reductions of endo-MLS strain were more evident than those of global, mid-MLS, and epi-MLS. This same pattern was seen in each of the ischemic territories of the anterior descending, circumflex, and right coronary arteries. Immediate improvement in endo-MLS following PCI was seen in 48% of patients. The time from symptom onset to balloon time was markedly longer in those with WFD (P < .0001). CONCLUSIONS: Multilayer SPE is a sensitive method that identifies serial alterations in focal myocardial function following successful PCI for STEMI. Layer-specific reductions in endo-MLS appeared more evident than decreases in global LV strain. Prolonged total ischemic time prior to PCI was directly related to the incidence of WFD.

Echocardiographic assessment of simultaneously measured left ventricular filling pressures in patients with normal left ventricular ejection fraction.

BACKGROUND: Assessment of left ventricular (LV) diastolic function is part of routine echocardiographic examinations. Accuracy of the 2016 ASE/EACVI algorithm to detect LV diastolic dysfunction in patients with a normal LV ejection fraction (LVEF) has been examined but simultaneous measurements of LV pressures and echocardiographic parameters of diastolic function are sparse. METHODS: The accuracy of multiple echo parameters of diastolic dynamics and the 2016 guidelines were assessed by simultaneous transthoracic echocardiography and LV pressure recordings in 120 patients (derivation cohort) and 60 patients (validation cohort) with suspected coronary artery disease and normal LVEF. Receiver-operating characteristic (ROC) curves defined optimal cut points for each echocardiographic parameter. A new algorithm was proposed to estimate LV diastolic pressures using 5 parameters based on ROC data: tricuspid regurgitation velocity >280cm/s, average e' <9 cm/s, average E/e' ratio >13, velocity of pulmonary vein A-wave reversal >32 cm/s, and left atrial volume index >32 mL/m2 . Performances of the 2016 guidelines and a proposed algorithm were examined for detecting a LV pre-A >12 and LV end-diastolic pressure (LVEDP) >15 mm Hg. RESULTS: In the derivation cohort, the 2016 algorithm identified an elevated LVEDP >15 mm Hg with an accuracy of 74.2% (63.8-82.9); the modified algorithm improved accuracy to 86.0% (77.6-92.1), P < .05. In the validation cohort, the proposed algorithm improved sensitivities with accuracies remaining like the 2016 algorithm. CONCLUSIONS: LV diastolic pressures in patients with normal LVEF were reliably assessed by the 2016 guidelines. The proposed algorithm improved sensitivities and may improve the accuracies for detecting abnormal LV filling pressures.

Advanced Glycation End Products Induce Vascular Smooth Muscle Cell-Derived Foam Cell Formation and Transdifferentiate to a Macrophage-Like State.

BACKGROUND: Advanced glycation end products play an important role in diabetic atherosclerosis. The effects of advanced glycation end products (AGEs) on vascular smooth muscle cell- (VSMC-) derived foam cell formation and phenotypic transformation are unknown. METHODS: Serological and histological samples were obtained from diabetic amputation patients and accident amputation patients from the Affiliated Hospital of Jiangsu University. CD68/Actin Alpha 2 (ACTA2) coimmunofluorescence sections were used to quantify the number of VSMCs with macrophage-like phenotypes. Western blotting was used to detect the expression of the receptor of advanced glycation end products in vascular samples. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the level of serum Nε-carboxymethyl-lysine (CML). In vitro oil red O staining was used to examine lipid accumulation in VSMCs stimulated by CML. The expression of VSMCs and macrophage markers was measured by western blotting and quantitative real-time PCR. Furthermore, changes in VSMC migration and secretion were detected by the Transwell assay and ELISA. RESULTS: In the arterial plaque sections of diabetic patients, VSMCs transformed to a macrophage-like phenotype. The serum CML and RAGE levels in the plaques were significantly higher in the diabetes group than those in the healthy control group and were significantly related to the number of macrophage-like VSMCs. CML stimulation promoted intracellular lipid accumulation. However, CML stimulation decreased the expression of VSMC markers and increased the expression of macrophage phenotype markers. Finally, CML promoted smooth muscle cell migration and the secretion of proinflammatory-related factors. CONCLUSIONS: CML induces VSMC-derived foam cell formation, and VSMCs transdifferentiate to a macrophage-like state, which may be mediated by the activation of RAGE.

Extracellular cyclophilin A induces cardiac hypertrophy via the ERK/p47phox pathway.

Excessive reactive oxygen species (ROS) are a critical driver of cardiac hypertrophy developing into heart failure. Cyclophilin A (CyPA), a member of the cyclophilin family, has been highlighted as a main secreted ROS-induced factor. The mechanism by which extracellular CyPA interacts with cardiomyocytes is unclear. We showed that extracellular CyPA is upregulated in cardiac hypertrophy rats and expressed around hypertrophic cardiomyocytes. Cell experiments further confirmed that extracellular CyPA induces H9c2 cardiomyocytes hypertrophy via ROS generation. Extracellular CyPA-induced ROS is derived from nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, and extracellular CyPA activates p47phox membrane translocation through ERK1/2 pathway. When blocking extracellular matrix metalloproteinase inducer (EMMPRIN), most of the extracellular CyPA effects were significantly inhibited. The current study shows that extracellular CyPA is one of the key factors linking oxidative stress and cardiac hypertrophy, and may be a potential target for cardiac hypertrophy therapy.

Role of Macrophages in the Progression and Regression of Vascular Calcification.

Vascular calcification is an abnormal cell-mediated process in which bone-specific hydroxyapatite crystals are actively deposited on the blood vessel wall and is a significant pathological basis for the increased incidence and mortality of adverse cardiovascular events. Macrophages play an important regulatory role in the occurrence, development, and regression of vascular calcification. After the tissue microenvironment changes, macrophages subsequently change their polarity and phenotype or secrete functional substances as an adaptive response. As research on macrophages continue to move into this field, we gain a new understanding of the mechanism of the formation and regression of vascular calcification, which might offer valuable new intervention targets for the prevention and inhibition of vascular calcification. This review summarizes a wealth of research in this field and explores the roles of macrophages in the development process of vascular calcification.

Macrophage galectin-3 enhances intimal translocation of vascular calcification in diabetes mellitus.

The clinical risks and prognosis of diabetic vascular intimal calcification (VIC) and medial calcification (VMC) are different. This study aims to investigate the mechanism of VIC/VMC translocation. Anterior tibial arteries were collected from patients with diabetic foot amputation. The patients were then divided into VIC and VMC groups. There were plaques in all anterior tibial arteries, while the enrichment of galectin-3 in arterial plaques in the VIC group was significantly higher than that in the VMC group. Furthermore, a macrophage/vascular smooth muscle cell (VSMC) coculture system was constructed. VSMC-derived extracellular vesicles (EVs) was labeled with fluorescent probe. After macrophages were pretreated with recombinant galectin-3 protein, the migration of VSMC-derived EVs and VSMC-derived calcification was more pronounced. And anti-galectin-3 antibody can inhibit this process of EVs and calcification translocation. Then, lentivirus (LV)-treated bone marrow cells (BMCs) were transplanted into apolipoprotein E-deficient (ApoE-/-) mice, and a diabetic atherosclerosis mouse model was constructed. After 15 wk of high-fat diet, ApoE-/- mice transplanted with LV-shgalectin-3 BMCs exhibited medial calcification and a concentrated distribution of EVs in the media. In conclusion, upregulation of galectin-3 in macrophages promotes the migration of VSMC-derived EVs to the intima and induces diabetic vascular intimal calcification.NEW & NOTEWORTHY The clinical risk and prognosis of vascular intimal and medial calcification are different. Macrophage galectin-3 regulates the migration of vascular smooth muscle cell-derived extracellular vesicles and mediates diabetic vascular intimal/medial calcification translocation. This study may provide insights into the early intervention in diabetic vascular calcification.

Nε-Carboxymethyl-Lysine Negatively Regulates Foam Cell Migration via the Vav1/Rac1 Pathway.

BACKGROUND: Macrophage-derived foam cells play a central role in atherosclerosis, and their ultimate fate includes apoptosis, promotion of vascular inflammation, or migration to other tissues. Nε-Carboxymethyl-lysine (CML), the key active component of advanced glycation end products, induced foam cell formation and apoptosis. Previous studies have shown that the Vav1/Rac1 pathway affects the macrophage cytoskeleton and cell migration, but its role in the pathogenesis of diabetic atherosclerosis is unknown. METHODS AND RESULTS: In this study, we used anterior tibiofibular vascular samples from diabetic foot amputation patients and accident amputation patients, and histological and cytological tests were performed using a diabetic ApoE-/- mouse model and primary peritoneal macrophages, respectively. The results showed that the atherosclerotic plaques of diabetic foot amputation patients and diabetic ApoE-/- mice were larger than those of the control group. Inhibition of the Vav1/Rac1 pathway reduced vascular plaques and promoted the migration of macrophages to lymph nodes. Transwell and wound healing assays showed that the migratory ability of macrophage-derived foam cells was inhibited by CML. Cytoskeletal staining showed that advanced glycation end products inhibited the formation of lamellipodia in foam cells, and inhibition of the Vav1/Rac1 pathway restored the formation of lamellipodia. CONCLUSION: CML inhibits the migration of foam cells from blood vessels via the Vav1/Rac1 pathway, and this process affects the formation of lamellipodia.

Exosome derived from CD137-modified endothelial cells regulates the Th17 responses in atherosclerosis.

The role of exosomes derived from endothelial cells (ECs) in the progression of atherosclerosis (AS) and inflammation remains largely unexplored. We aimed to investigate whether exosome derived from CD137-modified ECs (CD137-Exo) played a major role in AS and to elucidate the potential mechanism underlying the inflammatory effect. Exosomes derived from mouse brain microvascular ECs treated with agonist anti-CD137 antibody were used to explore the effect of CD137 signalling in AS and inflammation in vitro and vivo. CD137-Exo efficiently induced the progression of AS in ApoE-/- mice. CD137-Exo increased the proportion of Th17 cells both in vitro and vivo. The IL-6 contained in CD137-Exo which is regulated by Akt and NF-КB pathway was verified to activate Th17 cell differentiation. IL-17 increased apoptosis, inhibited cell viability and improved lactate dehydrogenase (LDH) release in ECs subjected to inflammation induced by lipopolysaccharide (LPS). The expression of soluble intercellular adhesion molecule1 (sICAM-1), monocyte chemoattractant protein-1 (MCP-1) and E-selectin in the supernatants of ECs after IL-17 treatment was dramatically increased. CD137-Exo promoted the progression of AS and Th17 cell differentiation via NF-КB pathway mediated IL-6 expression. This finding provided a potential method to prevent local and peripheral inflammation in AS.

A Case of Transcatheter Aortic Valve Replacement for the Treatment of Severe Aortic Stenosis with Multiple Organ Dysfunction.

A 77-year-old woman with extremely high risk of mortality due to severe aortic stenosis (AS) and multiple organ failure was admitted to the affiliated hospital of Jiangsu University. She did not receive regular treatment since being diagnosed with AS 17 months previously. Frequent breakout of acute left heart failure after admission, with a low ostium of the left coronary artery showed by computed tomography, the patient underwent transcatheter aortic valve replacement (TAVR). Though cardiac conduction system abnormalities and a short-term elevation of pulmonary arterial pressure occurred in this patient after TAVR, she eventually recovered and her quality of life improved significantly. As the population adapted to TAVR keeps expanding, we believe this operation will play a more important role in the treatment of AS patients.

18F-FDG uptake velocity but not uptake level is associated with progression of carotid plaque.

OBJECTIVES: The objective of this study was to evaluate whether baseline 18F-fluorodeoxyglucose (FDG) uptake is associated with carotid plaque progression. METHODS: A total of 156 subjects with carotid plaque were enrolled and underwent carotid magnetic resonance imaging (MRI) (at baseline and the 12-month follow-up) and positron emission tomography-computed tomography (PET-CT) (baseline). Carotid plaque progression was evaluated by two indices (the incidence of plaque progression and percentage of plaque increase) with three-dimensional (3D) imaging, while the 18F-FDG uptake was evaluated by the 18F-FDG uptake levels and 18F-FDG uptake velocity. The association between plaque progression and 18F-FDG uptake was investigated by the trend test and multivariate logistic regression analysis. RESULTS: Of the 156 subjects, 80 (51.3%) showed carotid plaque progression during the 12-month follow-up. Firstly, no association was found between 18F-FDG uptake levels and plaque progression. Secondly, significant differences in the incidence of plaque progression were observed among the groups with different uptake velocities, showing a significant decreasing trend ranging from high to intermediate to low (p = 0.002, trend test). After adjusting for covariates, an adequate prediction of the 18F-FDG uptake velocity for the incidence of plaque progression was revealed (OR = 0.682, p < 0.05). In addition, no association was found between the 18F-FDG uptake velocity and the percentage of plaque increase in the subjects with plaque progression (p = 0.757, trend test). CONCLUSIONS: Our findings suggest 18F-FDG uptake velocity is independently associated with the incidence of carotid plaque progression. Additionally, the 18F-FDG uptake velocity, as another important parameter of PET-CT, warrants further study in future clinical research. KEY POINTS: • The18F-FDG uptake levels were not associated with the carotid plaque progression. • The18F-FDG uptake velocity could predict the incidence of carotid plaque progression. • The18F-FDG uptake velocity with related factors warrants more attention in future clinical research.

Mechanisms of Matrix Vesicles Mediating Calcification Transition in Diabetic Plaque.

Vascular calcification is a key character of advanced plaque in diabetic atherosclerosis. Microcalcification induces plaque rupture, whereas macrocalcification contributes to plaque stability. However, there is still no clear explanation for the formation and transition of these two types of calcification. Based on existing work and the latest international progress, this article provides a brief review of four aspects: calcification transition in plaque; matrix vesicle-mediated calcification transition in plaque; regulation mechanism of matrix vesicle-mediated calcification transition in diabetic plaque; and proposal of a new hypothesis, which may offer a new perspective on the study of the mechanism of calcification transition in plaque.

CD137-CD137L Signaling Affects Angiogenesis by Mediating Phenotypic Conversion of Macrophages.

BACKGROUND: Angiogenesis in atherosclerotic plaque is an important factor causing plaque hemorrhage, vulnerability, and rupture, and different phenotypes of macrophages have different effects on angiogenesis. Our previous study has demonstrated CD137-CD137L signaling, a pair of inflammatory costimulatory molecules, can promote angiogenesis in atherosclerotic plaque. Therefore, we aimed to investigate whether this signaling could affect angiogenesis by regulating phenotypic transition of macrophages. METHODS: Male mouse primary peritoneal macrophages were extracted by intraperitoneal injection of thioglycollate, and then flow cytometry was used to detect the expression of CD137. Flow cytometry, Western blotting, quantitative real-time PCR, and enzyme-linked immunosorbent assay (ELISA) were used to assess the phenotypic changes of macrophages after different treatment. Mouse brain microvascular endothelial cells (bEnd.3) were cocultured with macrophages, and tube formation was assessed to examine angiogenesis. RESULTS: We found that the number of junctions and branches of bEnd.3 were increased when CD137-CD137L signaling was activated, while such number was further increased when bEnd.3 were cocultured with macrophages. Flow cytometry showed that CD137 was expressed on almost all primary peritoneal macrophages. The expression of CD86 was decreased in the agonist CD137L group and increased in the agonist CD137L + inhibitory anti-CD137 antibody group after adding the CD137 inhibitor. The expression of CD206 in each group exhibited opposite trend compared with CD86. Moreover, the expression of inducible nitric oxide synthase at the mRNA, and protein levels were decreased after stimulating CD137-CD137L signaling, and such downward trend was reversed when CD137-CD137L signaling was inhibited. Furthermore, the expression of arginase-1 was opposite to that of inducible nitric oxide synthase. Enzyme-linked immunosorbent assay indicated that the content of interleukin-12 (IL-12) in the supernatant of macrophages in the agonist CD137L group was lower than that in the control group, and its content in the inhibited group was higher than that in the activated group. The change of interleukin-10 (IL-10) content in macrophage supernatant was opposite to that of IL-12. When AKT serine/threonine kinase 1 (Akt1) inhibitor was used to inhibit the phenotypic transformation of macrophages induced by CD137-CD137L, the number of junctions and branches formed by bEnd.3 was decreased compared with the coculture group. CONCLUSIONS: These results indicated that CD137-CD137L signaling could promote angiogenesis by regulating phenotypic transition of macrophages of male mice.

Increased ASL-CBF in the right amygdala predicts the first onset of depression in healthy young first-degree relatives of patients with major depression.

Healthy first-degree relatives of patients with major depression are at an elevated risk of developing depression, and regional cerebral blood flow (CBF) alterations are observed in patients with depression. Therefore, in a 33-month follow-up study, we used arterial spin labeling-magnetic resonance imaging (ASL-MRI) to investigate quantitative CBF before and after the diagnosis of depression in healthy young adults with and without first-degree relatives with major depression (FH + and FH-, respectively). In cross-sectional and longitudinal CBF comparisons, CBF in the right amygdala was increased or decreased. Additionally, a significant correlation was observed between the altered CBF in the right amygdala and the scores on the 17-item Hamilton Depression Rating Scale (HDRS) in the FH + group. Furthermore, logistic regression and receiver operating characteristic curve analyses showed that increased CBF in the right amygdala at baseline predicted the subsequent onset of depression in the FH + group. Our results suggest that among healthy young adults with a familial risk of depression, those who exhibit increased CBF in the amygdala are susceptible to developing this disease.