scholarly journals Purple Potato Extract Promotes Intestinal Epithelial Differentiation and Barrier Function by Activating AMP-Activated Protein Kinase

2018 ◽  
Vol 62 (4) ◽  
pp. 1700536 ◽  
Author(s):  
Xiaofei Sun ◽  
Min Du ◽  
Duroy A. Navarre ◽  
Mei-Jun Zhu
Keyword(s):  
Protein Kinase ◽  
Barrier Function ◽  
Epithelial Differentiation ◽  
Intestinal Epithelial ◽  
Potato Extract ◽  
Amp Activated Protein Kinase

scholarly journals Deletion of intestinal epithelial AMP-activated protein kinase alters distal colon permeability but not glucose homeostasis

2021 ◽  
Vol 47 ◽  
pp. 101183
Author(s):  
Séverine Olivier ◽  
Camille Pochard ◽  
Hanna Diounou ◽  
Vanessa Castillo ◽  
Jordane Divoux ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Glucose Homeostasis ◽  
Distal Colon ◽  
Intestinal Epithelial ◽  
Amp Activated Protein Kinase

Abstract 5559: Role of AMP-activated Protein Kinase in Ischemia-Reperfusion-Induced Barrier Failure in Endothelial Monolayers

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Muhammad Assad ◽  
Muhammad Arshad ◽  
Frauke V Haertel ◽  
Muhammad Aslam ◽  
Ingrid Fleming ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Barrier Function ◽  
Ischemia Reperfusion ◽  
Fold Increase ◽  
Gap Formation ◽  
Endothelial Monolayers ◽  
Ampk Phosphorylation ◽  
Barrier Failure ◽  
Amp Activated Protein Kinase

Background: Ischemia-reperfusion provokes endothelial barrier dysfunction leading to edema formation and organ failure. The AMP-activated protein kinase (AMPK) is a fuel sensor which becomes activated under ischemia. It is now apparent that AMPK may also play important roles in stabilization of cell-adhesion. Here, it is hypothesized that AMPK may play an important role in protection barrier function under metabolic stress. Methods and Results: Overexpression of a dominant negative AMPK mutant in endothelial monolayers from human umbilical veins (EC) caused a 2-fold increase in basal permeability (albumin flux across the monolayers). In accordance, downregulation of AMPK by siRNA (~60%) leads to gap formation between adjacent EC, disintegration of cell adhesion structures and alterations of the cytoskeleton (loss of VE-cadherin at cell borders, actin stress fiber formation; immunocytochemistry), indicating that AMPK plays an important role in maintenance of barrier integrity. To analyse the role of AMPK on barrier function EC were exposed to ischemia (40 min, Po 2 <5 mm Hg; pH 6.4) followed by reperfusion (40 min, Po 2 =140 mm Hg; pH 7.4). Ischemia caused an immediate increase in permeability (gap formation, video-imaging technique) and a 3-fold increase in AMPK activity (AMPK phosphorylation; western blot) after 40 min. During reperfusion gap formation was further increased by 307± 9 % (P<0.05, n=5) within the ongoing 40 min. In contrast, AMPK phosphorylation rapidly declined to basal level within the first 10 minutes of reperfusion. However, addition of AICAR (AMPK activator; 5-aminoimidizole-4-carboxamide riboside), at the onset of reperfusion caused a rapid increase in AMPK phosphorylation and abolished the reperfusion-induced gap formation. Pretreatment of the cells with AICAR before the onset of ischemia reduced reperfusion-induced gap formation by 50 %. Conclusion: AMPK is involved in maintenance of cell-cell contacts and stabilization of basal barrier function. Pharmacological activation of AMPK within the first minutes of reperfusion can prevent hyperpermeability induced by reperfusion stress. Hence, activation of AMPK may provide a new therapeutic option to prevent ischemia-reperfusion barrier failure.

scholarly journals MicroRNAs Control Intestinal Epithelial Differentiation, Architecture, and Barrier Function

2010 ◽  
Vol 139 (5) ◽  
pp. 1654-1664.e1 ◽  
Author(s):  
Lindsay B. McKenna ◽  
Jonathan Schug ◽  
Anastassios Vourekas ◽  
Jaime B. McKenna ◽  
Nuria C. Bramswig ◽  
...  
Keyword(s):  
Barrier Function ◽  
Epithelial Differentiation ◽  
Intestinal Epithelial

scholarly journals Activation of AMP-Activated Protein Kinase by a Plant-Derived Dihydroisosteviol in Human Intestinal Epithelial Cell

2013 ◽  
Vol 36 (4) ◽  
pp. 522-528 ◽  
Author(s):  
Chatchai Muanprasat ◽  
Lalida Sirianant ◽  
Sutthipong Sawasvirojwong ◽  
Sureeporn Homvisasevongsa ◽  
Apichart Suksamrarn ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Epithelial Cell ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial ◽  
Human Intestinal Epithelial Cell ◽  
Amp Activated Protein Kinase

scholarly journals Polyamines modulate the subcellular localization of RNA-binding protein HuR through AMP-activated protein kinase-regulated phosphorylation and acetylation of importin α1

2007 ◽  
Vol 409 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Tongtong Zou ◽  
Lan Liu ◽  
Jaladanki N. Rao ◽  
Bernard S. Marasa ◽  
Jie Chen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Subcellular Localization ◽  
Nuclear Import ◽  
Rna Binding ◽  
Binding Protein ◽  
Phosphorylation Site ◽  
Rna Binding Protein ◽  
Intestinal Epithelial ◽  
Ampk Activation ◽  
Amp Activated Protein Kinase

Polyamines are required for maintenance of intestinal epithelial integrity, and a decrease in cellular polyamines increases the cytoplasmic levels of RNA-binding protein HuR stabilizing p53 and nucleophosmin mRNAs, thus inhibiting IEC (intestinal epithelial cell) proliferation. The AMPK (AMP-activated protein kinase), an enzyme involved in responding to metabolic stress, was recently found to be implicated in regulating the nuclear import of HuR. Here, we provide evidence showing that polyamines modulate subcellular localization of HuR through AMPK-regulated phosphorylation and acetylation of Impα1 (importin α1) in IECs. Decreased levels of cellular polyamines as a result of inhibiting ODC (ornithine decarboxylase) with DFMO (D,L-α-difluoromethylornithine) repressed AMPK activity and reduced Impα1 levels, whereas increased levels of polyamines as a result of ODC overexpression induced both AMPK and Impα1 levels. AMPK activation by overexpression of the AMPK gene increased Impα1 but reduced the cytoplasmic levels of HuR in control and polyamine-deficient cells. IECs overexpressing wild-type Impα1 exhibited a decrease in cytoplasmic HuR abundance, while cells overexpressing Impα1 proteins bearing K22R (lacking acetylation site), S105A (lacking phosphorylation site) or K22R/S105A (lacking both sites) mutations displayed increased levels of cytoplasmic HuR. Ectopic expression of these Impα1 mutants also prevented the increased levels of cytoplasmic HuR following polyamine depletion. These results indicate that polyamine-mediated AMPK activation triggers HuR nuclear import through phosphorylation and acetylation of Impα1 in IECs and that polyamine depletion increases cytoplasmic levels of HuR as a result of inactivation of the AMPK-driven Impα1 pathway.

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