Objective: Microtubules are important in signal transduction temporal-spatial organization. Full expression of angiotensin II (Ang II) signaling in vascular smooth muscle cells (VSMCs) is dependent on the reactive oxygen species (ROS) derived from nicotinamide-adenine dinucleotide phosphate (NAD(P)H) oxidase and the dynamic association of the Ang II type 1 receptor (AT1R) with caveolae/lipid rafts. Translocation of the small GTPase Rac1 to the plasma membrane is an essential step for activation of NAD(P)H oxidase; however, its precise localization in the plasma membrane after agonist stimulation and how it is targeted are unknown. We hypothesized that microtubules are involved in regulating multiphasic Ang II signaling events in VSMC.
Methods And Results: We show that Ang II promotes Rac1 and AT1R trafficking into caveolae/lipid rafts, which is blocked by disruption of microtubules with nocodazole. As a consequence, nocodazole significantly inhibits Ang II-stimulated H2O2 production, its downstream ROS-dependent epidermal growth factor receptor transactivation, Akt phosphorylation, and vascular hypertrophy without affecting Rac1 activation or ROS-independent extracellular signal-regulated kinase 1/2 phosphorylation.
Conclusions: These results suggest that proper Rac1 and AT1R trafficking into caveolae/lipid rafts requires the integrity of microtubules and provide insight into the essential role of microtubules for the spatial-temporal organization of ROS-dependent and caveolae/lipid rafts-dependent AT(1)R signaling linked to vascular hypertrophy.
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http://dx.doi.org/10.1161/01.ATV.0000132400.25045.2a | DOI Listing |
Cell Signal
December 2024
Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China; Department of General Surgery, Drum Tower Clinical Medical College of Nanjing Medical University, Nanjing, China; Department of General Surgery, Taikang Xianlin DrumTower Hospital, Nanjing, China. Electronic address:
Lipid rafts are highly heterogeneous and dynamic microdomains involved in molecule trafficking and signaling transduction. This study investigates the role of lipid rafts in gastric cancer and their key regulators. Analyzing FFPE samples from 111 gastric cancer patients, we found that high lipid raft levels predict poor prognosis.
View Article and Find Full Text PDFAdv Exp Med Biol
August 2023
Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey.
The plasma membrane is not a uniform phospholipid bilayer; it has specialized membrane nano- or microdomains called lipid rafts. Lipid rafts are small cholesterol and sphingolipid-rich plasma membrane islands. Although their existence was long debated, their presence in the plasma membrane of living cells is now well accepted with the advent of super-resolution imaging techniques.
View Article and Find Full Text PDFDrug Des Devel Ther
March 2022
Department of Biochemistry, Cancer Institute of the Second Affiliated Hospital (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), School of Medicine, Zhejiang University, Hangzhou, 310058, People's Republic of China.
Purpose: T-DM1 is an antibody-drug conjugate (ADC) consisting of trastuzumab and DM1 linked together. T-DM1 binds to human epidermal growth factor receptor-2 (HER2) in tumors and then triggers the endocytosis of T-DM1 and release of payload. Therefore, endocytosis efficacy is considered as a critical step for the initiation of T-DM1 therapy; however, the endocytosis mechanism of T-DM1 remains poorly understood.
View Article and Find Full Text PDFMolecules
July 2021
Centre for Stem Cell Research (CSCR) (A Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore 632002, TN, India.
Delivering nucleic acids into the endothelium has great potential in treating vascular diseases. However, endothelial cells, which line the vasculature, are considered as sensitive in nature and hard to transfect. Low transfection efficacies in endothelial cells limit their potential therapeutic applications.
View Article and Find Full Text PDFCancers (Basel)
July 2021
Biomedical Section, University of Hull, Cottingham Road, Hull HU6 7RX, UK.
Procoagulant activity of tissue factor (TF) in response to injury or inflammation is accompanied with cellular signals which determine the fate of cells. However, to prevent excessive signalling, TF is rapidly dissipated through release into microvesicles, and/or endocytosis. To elucidate the mechanism by which TF signalling may become moderated on the surface of cells, the associations of TF, fVII/fVIIa, PAR2 and caveolin-1 on MDA-MB-231, BxPC-3 and 786-O cells were examined and compared to that in cells lacking either fVII/fVIIa or TF.
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