Monocyte-to-macrophage differentiation, which can be initiated by physiological or atherogenic factors, is a pivotal process in atherogenesis, a disorder in which monocytes adhere to endothelial cells and subsequently migrate into the subendothelial spaces, where they differentiate into macrophages and macrophage-derived foam cells and cause atherosclerotic lesions. However, the monocyte-differentiation signaling pathways that are activated by atherogenic factors are poorly defined. Here we report that the AMP-activated protein kinase α1 (AMPKα1) in monocytes promotes atherosclerosis by increasing monocyte differentiation and survival. Exposure of monocytes to oxidized low-density lipoprotein, 7-ketocholesterol, phorbol 12-myristate 13-acetate, or macrophage colony-stimulated factor (M-CSF) significantly activated AMPK and promoted monocyte-to-macrophage differentiation. M-CSF-activated AMPK is via M-CSF receptor-dependent reactive oxygen species production. Consistently, genetic deletion of AMPKα1 or pharmacological inhibition of AMPK blunted monocyte-to-macrophage differentiation and promoted monocyte/macrophage apoptosis. Compared with apolipoprotein E knock-out () mice, which show impaired clearing of plasma lipoproteins and spontaneously develop atherosclerosis, /α mice showed reduced sizes of atherosclerotic lesions and lesser numbers of macrophages in the lesions. Furthermore, aortic lesions were decreased in mice transplanted with/α bone marrow and in myeloid-specific AMPKα1-deficient mice. Finally, rapamycin treatment, which abolished delayed monocyte differentiation in/α mice, lost its atherosclerosis-lowering effects in these mice. Mechanistically, we found that AMPKα1 regulates FoxO3-dependent expression of both LC3 and ULK1, which are two important autophagy-related markers. Rapamycin treatment increased FoxO3 activity as well as LC3 and ULK1 expressions in macrophages from α mice. Our results reveal that AMPKα1 deficiency impairs autophagy-mediated monocyte differentiation and decreases monocyte/macrophage survival, which attenuates atherosclerosis in mice.

Tiger frog virus (TFV), in the genusRanavirus of the family Iridoviridae, causes high mortality of cultured tiger frog tadpoles in China. To explore the cellular entry mechanism of TFV, HepG2 cells were treated with drugs that inhibit the main endocytic pathways. We observed that TFV entry was inhibited by NH 4 Cl, chloroquine, and bafilomycin, which can all elevate the pH of acidic organelles. In contrast, TFV entry was not influenced by chlorpromazine or overexpression of a dominant-negative form of Esp15, which inhibit the assembly of clathrin-coated pits. These results suggested that TFV entry was not associated with clathrinmediated endocytosis, but was related to the pH of acidic organelles. Subsequently, we found that endocytosis of TFV was dependent on membrane cholesterol and was inhibited by the caveolin-1 scaffolding domain peptide. Dynamin and actin were also required for TFV entry. In addition, TFV virions colocalized with the cholera toxin subunit B, indicating that TFV enters as caveola-internalized cargo into the Golgi complex. Taken together, our results demonstrated that TFV entry occurs by caveola-mediated endocytosis with a pH-dependent step. This atypical caveola-mediated endocytosis is different from the clathrin-mediated endocytosis of frog virus 3 (FV3) by BHK cells, which has been recognized as a model for iridoviruses. Thus, our work may help further the understanding of the initial steps of iridovirus infection in lower vertebrates.

The recrudescence of breast cancer can partly be attributed to poor understanding of the early steps and the mechanisms involved in breast cancer metastasis, especially how tumor inflammatory cells including tumor-associated macrophages (TAM) affect invasion process. However, invasion-related biological studies in traditional in vitro assays or in vivo models are challenging due to the arduousness in establishing models that precisely reproduce the tumor invasion environment. To this end, we proposed a juxtaposed dual-layer cell-loaded hydrogels biomimetic microfluidic system and formed monolayer size-selective permeable vascular endothelial barriers besides the dual layer to mimic mammalian blood vessels. We clarified that in this system, TAM promoted the invasion of breast cancer cells, whereas breast cancer cells maintained the phenotype of TAM cells and promoted the differentiation of U937 cells into TAM. It formed a tumor-macrophage bidirectional crosstalk system. This system could be used for drug screening. So finally, through the calculation of the survival rate of breast cancer cells when cocultured with different macrophages under paclitaxel treatment, we analyzed the antagonism of tumor-macrophage bidirectional crosstalk on anticancer drugs. K E Y W O R D S breast cancer, drug screening, invasion, microfluidic chip, tumor-associated macrophage

Vascular calcification (VC) is a strong predictor of cardiovascular morbidity and mortality, and is linked to ageing, diabetes and chronic kidney diseases (CKD). 1 Growing evidence now suggests that VC is an actively regulated process resembling bone remodelling, including both inductive and inhibitory processes. 2 Abnormal activation of the renin-angiotensin-aldosterone system plays an important role in the development of cardiovascular diseases, among which aldosterone (Aldo) is a major effector. 3 Aldo, a mineralocorticoid hormone, binds to mineralocorticoid receptor (MR) and then activates specific intracellular genomic pathways, thus regulating the homeostasis of the cardiovascular system. Once Aldo is overactivated, it can promote vascular oxidative stress, inflammation and apoptosis, 4 leading to an increased risk of target-organ damage. 5 Previous studies suggested that a MR inhibitor, spironolactone (Spiro) ameliorated CKD-related

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A rteriogenesis is a process of developing collateral circulation through the remodeling and growth of pre-existing collateral arteries after elevated shear stress induced by occlusion.1-3 Arteriogenesis takes place both during embryogenesis and in adult tissues. In the latter case, arteriogenesis, which usually occurs at sites of occlusion or physical disruption of pre-existing arterial conduits such as coronary artery occlusion or femoral artery ligation, plays a vital role in recovery from ischemic insults. 4,5 Understanding the biological factors that affect arteriogenesis will aid in the development of new treatments for patients with arterial stenosis and occlusions.There are 2 commonly considered mechanisms for arteriogenesis: expansion of pre-existing collaterals and de novo arteriogenesis. 2,6,7 Inflammation caused by mechanical hemodynamic forces, such as shear stress and circumferential wall tension, is considered a pivotal trigger and driver for arteriogenesis. 4,[8][9][10][11] Previous studies have shown that monocytes accumulated in the surrounding tissues of collateral vessels alter arterial occlusion. 7,[11][12][13] These macrophages are potent sources of cytokines and growth factors, which are required for natural adaptive arteriogenesis. In spite of a mounting number of putative arteriogenic factors, the exact mechanisms that regulate collateral remodeling are poorly characterized. Furthermore, the processes responsible for arteriogenesis, and its associated molecular signals are poorly understood.AMP-activated protein kinase (AMPK) is a serine/threonine kinase composed of α, β, and γ subunits. 14,15 The α subunit containing the α1 and α2 isoform is the catalytic subunit, whereas the β and γ are regulatory subunits that maintain the stability of the heterotrimer complex. As an energy sensor, AMPK is activated by various cellular stresses, such as hypoxia, nutrient deprivation, and oxidative stress. [16][17][18] Once activated, AMPK phosphorylates and regulates several downstream kinases that reduce energy demand and increase energy supply to maintain whole-body energy homeostasis. 19 In addition, AMPK also regulates many other cellular processes, including cell polarity, cell growth, and proliferation. [20][21][22] Emerging studies have demonstrated that AMPK is activated in response to shear or ischemic stress. 23,24 AMPK signaling is required for angiogenesis in vivo and in vitro. [25][26][27][28] However, there is no information on the consequences of AMPK deletion in arteriogenesis. In this study, we sought to examine the role © 2016 American Heart Association, Inc. Objective-AMP-activated protein kinase (AMPK), an energy and redox sensor, is activated in response to various cellular stresses, including hypoxia, nutrient deprivation, oxidative stress, and fluid shear stress at the site of vessel blockade. The activation of AMPK is involved in angiogenesis. However, it is unknown whether AMPK can influence arteriogenesis. Here, we demonstrate the contribution of macrophage AMPK to arteriogen...

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Objective: Long noncoding RNAs (lncRNAs) are potential biomarkers for cancers. Nevertheless, the ability of long noncoding RNA lung cancer-associated transcript 1 in patients with multiple myeloma remains unknown. The purpose of this current study was to figure out its function in multiple myeloma. Methods: Firstly, the expression of long noncoding RNA lung cancer-associated transcript 1 in cancer or normal tissues and serum from patients with multiple myeloma and normal donors was detected. Secondly, the expression of long noncoding RNA lung cancer-associated transcript 1 was overexpressed or silenced in U266 and H929 cells, respectively to detect changes of proliferation and apoptosis in multiple myeloma in vitro. Subsequently, the expression of transforming growth factor-β signaling pathway-related proteins was detected by western blot analysis. Finally, the effect of long noncoding RNA lung cancer-associated transcript 1 on the growth of multiple myeloma cells in vivo was evaluated by tumor xenograft in nude mice. Results: Long noncoding RNA lung cancer-associated transcript 1 was increased in cancer tissues and serum of patients with multiple myeloma as well as multiple myeloma cells, which was correlated with dismal prognosis of patients with multiple myeloma. Overexpression of long noncoding RNA lung cancer-associated transcript 1 promoted the activity of U266 and H929 cells, while inhibition of long noncoding RNA lung cancer-associated transcript 1 suppressed the activity of U266 and H929 cells. In addition, long noncoding RNA lung cancer-associated transcript 1 was found to promote activation of the transforming growth factor-β signaling pathway. Furthermore, long noncoding RNA lung cancer-associated transcript 1 knockdown restricted the growth of multiple myeloma cells in vivo. Conclusion: This study suggests that suppression of long noncoding RNA lung cancer-associated transcript 1 inhibits the activation of transforming growth factor-β signaling pathway, thereby inhibiting the growth of multiple myeloma cells.