AMPKα2 Deletion Causes Aberrant Expression and Activation of NAD(P)H Oxidase and Consequent Endothelial Dysfunction In Vivo

Wang, Shuangxi; Zhang, Miao; Liang, Bin; Xu, Jian; Xie, Zhonglin; Liu, Chao; Viollet, Benoı̂t; Yan, Di; Zou, Ming‐Hui

doi:10.1161/circresaha.109.212530

Cited by 286 publications

(288 citation statements)

References 39 publications

Supporting

Mentioning

268

Contrasting

Unclassified

Order By: Relevance

“…The AMPK signaling pathway is important in maintaining cellular survival during stress by regulating metabolic homeostasis (48). Consistent with the present findings, previous studies have suggested that the activation of the AMPK pathway suppresses the function of the NF-κB pathway (49)(50)(51)(52)(53)(54). AMPK has certain direct phosphorylation targets (55); however, it is possible that AMPK inhibits NF-κB signaling through its downstream effectors, including peroxisome proliferator-activated receptor γ co-activator 1α and sirtuin (silent mating type information regulation 2 homolog) 1, which suppress inflammatory factors.…”

Section: Discussionsupporting

confidence: 91%

Curcumin suppresses colon cancer cell invasion via AMPK-induced inhibition of NF–κB, uPA activator and MMP9

et al. 2016

View full text Add to dashboard Cite

Abstract. Curcumin, an active nontoxic ingredient of turmeric, possesses potent anti-inflammatory, antioxidant and anti-cancer properties; however, the molecular mechanisms of curcumin are not fully understood. The transcription factor nuclear factor-κB (NF-κB) is key in cellular processes, and the expression/activation of urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP9) are crucial for cell invasion. The present study investigated the hypothesis that curcumin inhibits colon cancer cell invasion by modulating NF-κB-mediated expression and activation of uPA and MMP9. Human colon cancer SW480 and LoVo cells were treated with various concentrations of curcumin. Curcumin was demonstrated to dose-dependently inhibit the adhesion and proliferation ability of LoVo and SW480 cells using Transwell and MTT assays, respectively. In addition, curcumin activated 5' AMP-activated protein kinase (AMPK) and suppressed p65 NF-κB phosphorylation, as shown by western blot analysis. Compound C, a potent AMPK inhibitor, abolished curcumin-induced inhibition of NF-κB, uPA and MMP9, suggesting that AMPK activation is responsible for curcumin-mediated NF-κB, uPA and MMP9 inhibition. The binding activity of NF-κB to DNA was examined and western blotting and quantitative polymerase reaction was performed to detect the effect of curcumin on the expression of uPA and MMP9. The present results revealed that curcumin significantly decreased the expression of uPA and MMP9 and NF-κB DNA binding activity. Furthermore, curcumin decreased the level of the p65 subunit of NF-κB binding to the promoter of the gene encoding uPA and MMP9, which suppressed transcriptional activation of uPA and MMP9. Overall, the present data suggest that curcumin inhibits colon cancer cell invasion via AMPK activation and subsequent inhibition of p65 NF-κB, uPA and MMP9. The therapeutic potential of curcumin for colon cancer metastasis required additional study.

show abstract

Section: Discussionsupporting

confidence: 91%

Curcumin suppresses colon cancer cell invasion via AMPK-induced inhibition of NF–κB, uPA activator and MMP9

et al. 2016

View full text Add to dashboard Cite

show abstract

“…These results strongly suggest that ROS-LKB1 might be required for AMPK activation by probucol in glioma cells. Studies [21,28] have demonstrated antioxidant effects of probucol and AMPK in vivo. This apparently contradictory observation might be similar to ischemic preconditioning by ROS, in which low levels of ROS precondition the tissues to prevent the massive production of reactive species in index hypoxia.…”

Section: Discussionmentioning

confidence: 99%

“…Total RNA (400 ng) from each sample was used for cDNA synthesis using the iScript cDNA synthesis kit (Bio-Rad Laboratories, Hercules, CA, USA) according to the manufacturer's instructions and as described previously [21] . Prepared cDNA samples were amplified and analyzed with PCR using the following primers: p27 Kip1 , 5'-CGCTTTTGTTC-GGTTTTGTT-3' (forward) and 5'-TTCGGAGCTGTTTAC-GTCTG-3' (reverse).…”

Section: Semi-quantitative Reverse Transcription Polymerase Chain Reamentioning

confidence: 99%

Probucol suppresses human glioma cell proliferation in vitro via ROS production and LKB1-AMPK activation

et al. 2014

View full text Add to dashboard Cite

Aim: Probucol, an anti-hyperlipidemic drug, has been reported to exert antitumor activities at various stages of tumor initiation, promotion and progression. In this study we examined whether the drug affected glioma cell growth in vitro and the underlying mechanisms. Methods: Human glioma U87 and glioblastoma SF295 cell lines were used. Cell proliferation was accessed using the cell proliferation assay and BrdU incorporation. The phosphorylation of AMPK, liver kinase B1 (LKB1) and p27 Kip1 was detected by Western blot. The activity of 26S proteasome was assessed with an in situ fluorescent substrate. siRNAs were used to suppress the expression of the relevant signaling proteins. Results: Treatment of U87 glioma cells with probucol (10-100 μmol/L) suppressed the cell proliferation in dose-and time-dependent manners. Meanwhile, probucol markedly increased the ROS production, phosphorylation of AMPK at Thr172 and LKB1 at Ser428 in the cells. Furthermore, probucol significantly decreased 26S proteasome activity and increased p27 Kip1 protein level in the cells in an AMPK-dependent manner. Probucol-induced suppression of U87 cell proliferation could be reversed by pretreatment with tempol (a superoxide dismutase mimetic), MG132 (proteasome inhibitor) or compound C (AMPK inhibitor), or by gene silencing of LKB1, AMPK or p27 Kip1 . Similar results were observed in probucol-treated SF295 cells. Conclusion: Probucol suppresses human glioma cell proliferation in vitro via ROS production and LKB1-AMPK activation, which reduces 26S proteasome-dependent degradation of p27 Kip1 .

show abstract

“…6, B, C, and F). Wang et al reported that deletion of AMPK␣2 results in the constitutive activation of NF-B in mouse aortic endothelial cells (47). In addition, many studies have reported that the activation of AMPK inhibits the NF-B pathway (48 -51).…”

Section: Discussionmentioning

confidence: 99%

AMP-activated Protein Kinase Suppresses Matrix Metalloproteinase-9 Expression in Mouse Embryonic Fibroblasts

Morizane

Thanos

Takeuchi

et al. 2011

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Matrix metalloproteinase-9 (MMP-9) plays a critical role in tissue remodeling under both physiological and pathological conditions. Although MMP-9 expression is low in most cells and is tightly controlled, the mechanism of its regulation is poorly understood. We utilized mouse embryonic fibroblasts (MEFs) that were nullizygous for the catalytic ␣ subunit of AMP-activated protein kinase (AMPK), which is a key regulator of energy homeostasis, to identify AMPK as a suppressor of MMP-9 expression. Total AMPK␣ deletion significantly elevated MMP-9 expression compared with wild-type (WT) MEFs, whereas single knock-out of the isoforms AMPK␣1 and AMPK␣2 caused minimal change in the level of MMP-9 expression. The suppressive role of AMPK on MMP-9 expression was mediated through both its activity and presence. Matrix metalloproteinase-9 (MMP-9, 2 gelatinase B) degrades denatured collagens and native collagen type IV, which is a major component of the extracellular matrix (ECM) and basement membranes (1). Under normal circumstances, the degradation of the ECM by MMP-9 is a tightly controlled process involved in physiological wound healing and embryo development (1, 2). Conversely, aberrant degradation of ECM by excess MMP-9 expression results in the pathologic destruction of connective tissue seen in cancer, arterial sclerosis, and rheumatoid arthritis (1, 3). Therefore, under physiological conditions, regulated MMP-9 expression is low (1), but the mechanisms behind this are obscure.AMP-activated protein kinase (AMPK) is a serine/threonine kinase, which regulates energy homeostasis and metabolic stress (4). AMPK acts as a sensor of cellular energy status and maintains the balance between ATP production and consumption. In mammals, AMPK exists as a heterotrimer with ␣, ␤, and ␥ subunits, each of which is encoded by two or three genes (␣1, ␣2, ␤1, ␤2, ␥1, ␥2, and ␥3). The ␣ subunit possesses catalytic activity, whereas the ␤ and ␥ subunits are regulatory and maintain the stability of the heterotrimer complex. The importance of AMPK␣ is illustrated by the fact that dual deficiency of AMPK␣1 and AMPK␣2 is embryonic lethal (5).Recent evidence suggests that AMPK has a much wider range of functions, including the regulation of cell growth, cell proliferation, cell polarity, and autophagy (6, 7). Because these functions are closely linked to the pathology of MMP-9-related diseases, including cancer, arterial sclerosis, and rheumatoid arthritis, we hypothesized that AMPK regulates MMP-9 expression. To address this, in the present study, we utilized AMPK␣-deficient mouse embryonic fibroblasts (MEFs) to investigate the effect of the genetic deletion and activation of AMPK on MMP-9 expression. EXPERIMENTAL PROCEDURESAntibodies, Recombinant Proteins, and Reagents-All antibodies, except for MMP-9 (Abcam, Cambridge, MA) and AMPK␣2 (Santa Cruz Biotechnology, Santa Cruz, CA), were purchased from Cell Signaling (Beverly, MA). Recombinant mouse TNF-␣, MMP-9, and MMP-2 proteins were obtained from R&D Systems (

show abstract

AMPKα2 Deletion Causes Aberrant Expression and Activation of NAD(P)H Oxidase and Consequent Endothelial Dysfunction In Vivo

Cited by 286 publications

References 39 publications

Curcumin suppresses colon cancer cell invasion via AMPK-induced inhibition of NF–κB, uPA activator and MMP9

Curcumin suppresses colon cancer cell invasion via AMPK-induced inhibition of NF–κB, uPA activator and MMP9

Probucol suppresses human glioma cell proliferation in vitro via ROS production and LKB1-AMPK activation

AMP-activated Protein Kinase Suppresses Matrix Metalloproteinase-9 Expression in Mouse Embryonic Fibroblasts

Contact Info

Product

Resources

About