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Magaye RR, Savira F, Xiong X, Huynh K, Meikle PJ, Reid C, Flynn BL, Kaye D, Liew D, Wang BH. Dihydrosphingosine driven enrichment of sphingolipids attenuates TGFβ induced collagen synthesis in cardiac fibroblasts. Int J Cardiol Heart Vasc 2021; 35:100837. [PMID: 34277924 PMCID: PMC8264607 DOI: 10.1016/j.ijcha.2021.100837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 01/22/2023]
Abstract
The sphingolipid de novo synthesis pathway, encompassing the sphingolipids, the enzymes and the cell membrane receptors, are being investigated for their role in diseases and as potential therapeutic targets. The intermediate sphingolipids such as dihydrosphingosine (dhSph) and sphingosine (Sph) have not been investigated due to them being thought of as precursors to other more active lipids such as ceramide (Cer) and sphingosine 1 phosphate (S1P). Here we investigated their effects in terms of collagen synthesis in primary rat neonatal cardiac fibroblasts (NCFs). Our results in NCFs showed that both dhSph and Sph did not induce collagen synthesis, whilst dhSph reduced collagen synthesis induced by transforming growth factor β (TGFβ). The mechanisms of these inhibitory effects were associated with the increased activation of the de novo synthesis pathway that led to increased dihydrosphingosine 1 phosphate (dhS1P). Subsequently, through a negative feedback mechanism that may involve substrate-enzyme receptor interactions, S1P receptor 1 expression (S1PR1) was reduced.
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Key Words
- Akt, protein kinase B
- CTGF, connective tissue growth factor
- Cardiac fibroblasts
- Cer, ceramide
- Cer1P, ceramide 1 phosphate
- Coll1a1, collagen 1a1
- Collagen synthesis
- Degs1, dihydroceramide desaturase 1 gene
- Des-1, dihydroceramide desaturase 1 enzyme
- Dihydrosphingosine
- ECM, extracellular matrix inhibitor of nuclear kappa B (NFKβ) kinase alpha and beta (IKKα/β)
- MA3PK, mitogen activated protein kinase kinase kinase
- MAPK, mitogren activated protein kinase
- MI, myocardial infarct
- MMP2, matrix metalloproteinase 2
- NCF, neonatal cardiac fibroblasts
- RPS6, ribosomal protein S6
- S1P, sphingosine-1 Phosphate
- S1PR1, sphingosine -1-phosphate receptor 1
- S1PRs, sphingosine 1 phosphate receptor 1-5
- SK1, sphingosine kinase 1
- Sph, sphingosine
- Sphingolipid
- TAK1, transforming growth factor β activating kinase 1
- TGFβ
- TGFβ, transforming growth factor β
- TIMP1, tissue inhibitor of metalloproteinase 1
- d7dhSph, deuterated dihydrosphingosine
- dhCer, dihydroceramide
- dhS1P, dihydrosphingosine 1 phosphate
- mTOR, mammalian target for rapamycin
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Affiliation(s)
- Ruth R. Magaye
- Biomarker Discovery Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
- Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia
| | - Feby Savira
- Biomarker Discovery Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
- Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia
| | - Xin Xiong
- Biomarker Discovery Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
- Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia
- Shanghai Institute of Heart Failure, Research Centre for Translational Medicine, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai 200120, PR China
| | - Kevin Huynh
- Metabolomics Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Peter J. Meikle
- Metabolomics Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia
- School of Public Health School, Curtin University, Perth, Australia
| | - Christopher Reid
- Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia
- School of Public Health School, Curtin University, Perth, Australia
| | - Bernard L. Flynn
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| | - David Kaye
- Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Danny Liew
- Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia
| | - Bing H. Wang
- Biomarker Discovery Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
- Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, Australia
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Abstract
Cocaine abuse leads to neuroinflammation, which, in turn, contributes to the pathogenesis of neurodegeneration associated with advanced HIV-1 infection. Autophagy plays important roles in both innate and adaptive immune responses. However, the possible functional link between cocaine and autophagy has not been explored before. Herein, we demonstrate that cocaine exposure induced autophagy in both BV-2 and primary rat microglial cells as demonstrated by a dose- and time-dependent induction of autophagy-signature proteins such as BECN1/Beclin 1, ATG5, and MAP1LC3B. These findings were validated wherein cocaine treatment of BV-2 cells resulted in increased formation of puncta in cells expressing either endogenous MAP1LC3B or overexpressing GFP-MAP1LC3B. Specificity of cocaine-induced autophagy was confirmed by treating cells with inhibitors of autophagy (3-MA and wortmannin). Intriguingly, cocaine-mediated induction of autophagy involved upstream activation of 2 ER stress pathways (EIF2AK3- and ERN1-dependent), as evidenced by the ability of the ER stress inhibitor salubrinal to ameliorate cocaine-induced autophagy. In vivo validation of these findings demonstrated increased expression of BECN1, ATG5, and MAP1LC3B-II proteins in cocaine-treated mouse brains compared to untreated animals. Increased autophagy contributes to cocaine-mediated activation of microglia since pretreatment of cells with wortmannin resulted in decreased expression and release of inflammatory factors (TNF, IL1B, IL6, and CCL2) in microglial cells. Taken together, our findings suggest that cocaine exposure results in induction of autophagy that is closely linked with neuroinflammation. Targeting autophagic proteins could thus be considered as a therapeutic strategy for the treatment of cocaine-related neuroinflammation diseases.
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Key Words
- 3-MA, 3-methyladenine
- ATF6, activating transcription factor 6
- ATG5, autophagy-related 5
- BCL2, B-cell CLL/lymphoma 2
- BECN1
- BECN1, Beclin 1, autophagy related
- Baf1, bafilomycin A1
- CCL2, chemokine (C-C motif) ligand 2
- DAPI: 4, 6-diamidino-2-phenylindole, dihydrochloride
- DDIT3, DNA-damage-inducible transcript 3
- EGFP, enhanced green fluorescent protein
- EIF2AK3, eukaryotic translation initiation factor 2-α kinase 3
- EIF2S1, eukaryotic translation initiation factor 2, subunit 1 α, 35kDa
- ER stress
- ER, endoplasmic reticulum
- ERN1, endoplasmic reticulum to nucleus signaling 1
- HIV, human immunodeficiency virus
- IL1B, interleukin 1, β
- IL6, interleukin 6
- MAP1LC3B
- MAP1LC3B, microtubule-associated protein 1 light chain 3
- METH, methamphetamine
- MTOR, mechanistic target of rapamycin
- NFKB1, nuclear factor of kappa light polypeptide gene enhancer in B-cells 1
- PBN, N-tert-butyl-α-phenylnitrone
- PPP1R3A, protein phosphatase 1, regulatory subunit 3A
- PtdIns3K, class III phosphatidylinositol 3-kinase
- ROS, reactive oxygen species
- RPS6, ribosomal protein S6
- TLR4, toll-like receptor 4
- TNF, tumor necrosis factor
- autophagy
- cocaine
- microglial cells
- neuroinflammation
- rPMCs, rat primary microglial cells
- wort, wortmannin
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Affiliation(s)
- Ming-Lei Guo
- a Department of Pharmacology and Experimental Neuroscience; Nebraska Medical Center; University of Nebraska Medical Center ; Omaha , NE , USA
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Xiong Y, Yepuri G, Forbiteh M, Yu Y, Montani JP, Yang Z, Ming XF. ARG2 impairs endothelial autophagy through regulation of MTOR and PRKAA/AMPK signaling in advanced atherosclerosis. Autophagy 2015; 10:2223-38. [PMID: 25484082 PMCID: PMC4502672 DOI: 10.4161/15548627.2014.981789] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Impaired autophagy function and enhanced ARG2 (arginase 2)-MTOR (mechanistic target of rapamycin) crosstalk are implicated in vascular aging and atherosclerosis. We are interested in the role of ARG2 and the potential underlying mechanism(s) in modulation of endothelial autophagy. Using human nonsenescent “young” and replicative senescent endothelial cells as well as Apolipoprotein E-deficient (apoe−/−Arg2+/+) and Arg2-deficient apoe−/− (apoe−/−arg2−/−) mice fed a high-fat diet for 10 wk as the atherosclerotic animal model, we show here that overexpression of ARG2 in the young cells suppresses endothelial autophagy with concomitant enhanced expression of RICTOR, the essential component of the MTORC2 complex, leading to activation of the AKT-MTORC1-RPS6KB1/S6K1 (ribosomal protein S6 kinase, 70kDa, polypeptide 1) cascade and inhibition of PRKAA/AMPK (protein kinase, AMP-activated, α catalytic subunit). Expression of an inactive ARG2 mutant (H160F) had the same effect. Moreover, silencing RPS6KB1 or expression of a constitutively active PRKAA prevented autophagy suppression by ARG2 or H160F. In senescent cells, enhanced ARG2-RICTOR-AKT-MTORC1-RPS6KB1 and decreased PRKAA signaling and autophagy were observed, which was reversed by silencing ARG2 but not by arginase inhibitors. In line with the above observations, genetic ablation of Arg2 in apoe−/− mice reduced RPS6KB1, enhanced PRKAA signaling and endothelial autophagy in aortas, which was associated with reduced atherosclerosis lesion formation. Taken together, the results demonstrate that ARG2 impairs endothelial autophagy independently of the L-arginine ureahydrolase activity through activation of RPS6KB1 and inhibition of PRKAA, which is implicated in atherogenesis.
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Key Words
- AKT/PKB, v-akt murine thymoma viral oncogene homolog 1
- ANOVA, analysis of variance
- AR, aortic roots
- ARG1, arginase 1
- ARG2, arginase 2
- ARGINASE
- Atg, autophagy-related
- BEC, S-12 bromoethyl-L-cystine-HCl
- BECN1, Beclin 1, autophagy-related
- Baf A1, bafilomycin A1
- CMV, cytomegalovirus
- EC, endothelial cell
- H160F, inactive mutant of mouse ARG2
- HAEC, human aortic endothelial cells
- HUVEC, human umbilical vein endothelial cells
- LC3, microtubule-associated protein 1 light chain 3
- LDL, low-density lipoprotein
- MTOR
- MTOR, mechanistic target of rapamycin
- NOS3/eNOS, nitric oxide synthase 3 (endothelial cell)
- PE, phosphatidylethanolamine
- PRKAA
- PRKAA/AMPK, protein kinase, AMP-activated, α catalytic subunit
- PtdIns3K, phosphatidylinositol 3-kinase
- RPS6, ribosomal protein S6
- RPS6KB1/S6K1, ribosomal protein S6 kinase, 70kDa, polypeptide 1
- SA-ß-gal, senescence-associated-β-gal
- SMC, smooth muscle cells
- SQSTM1/p62, sequestosome 1
- TP53/p53, tumor protein 53
- Three-MA, 3-methyladenine
- ULK1, unc-51 like autophagy activating kinase 1
- VWF, von Willebrand factor
- WT, wild type
- apoe−/−, Apolipoprotein E-deficient
- arg2−/−, arginase type II deficient
- atherosclerosis
- autophagy
- endothelial cells
- nor-NOHA, Nω-hydroxy-nor-Arginine
- senescence
- shRNA, short hairpin RNA
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Affiliation(s)
- Yuyan Xiong
- a Vascular Biology; Department of Medicine; Division of Physiology; Faculty of Science ; University of Fribourg ; Fribourg , Switzerland
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Akin D, Wang SK, Habibzadegah-Tari P, Law B, Ostrov D, Li M, Yin XM, Kim JS, Horenstein N, Dunn WA. A novel ATG4B antagonist inhibits autophagy and has a negative impact on osteosarcoma tumors. Autophagy 2014; 10:2021-35. [PMID: 25483883 PMCID: PMC4502682 DOI: 10.4161/auto.32229] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Autophagy has been implicated in the progression and chemoresistance of various cancers. In this study, we have shown that osteosarcoma Saos-2 cells lacking ATG4B, a cysteine proteinase that activates LC3B, are defective in autophagy and fail to form tumors in mouse models. By combining in silico docking with in vitro and cell-based assays, we identified small compounds that suppressed starvation-induced protein degradation, LC3B lipidation, and formation of autophagic vacuoles. NSC185058 effectively inhibited ATG4B activity in vitro and in cells while having no effect on MTOR and PtdIns3K activities. In addition, this ATG4B antagonist had a negative impact on the development of Saos-2 osteosarcoma tumors in vivo. We concluded that tumor suppression was due to a reduction in ATG4B activity, since we found autophagy suppressed within treated tumors and the compound had no effects on oncogenic protein kinases. Our findings demonstrate that ATG4B is a suitable anti-autophagy target and a promising therapeutic target to treat osteosarcoma.
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Key Words
- 3MA, 3-methyladenine
- ACTB, actin, beta
- ATG, autophagy-related
- ATG4B
- ATG4B, autophagy-related 4B, cysteine protease
- AV, autophagic vacuole
- BECN1, beclin 1, autophagy related
- CMPase, cytidine monophosphatase
- DMEM, Dulbecco's modified Eagle medium
- ECL, enhanced chemiluminescence
- FYVE, zinc-finger domain named after 4 cysteine-rich proteins: FAB1, YOTB, VAC1, and EEA1
- GABARAPL2, GABA(A) receptor-associated protein-like 2
- GFP, green fluorescent protein
- GST, glutathione S-transferase
- HRP, horseradish peroxidase
- IC50, half maximal inhibitory concentration
- IP, intraperitoneal
- LC3B
- MAP1LC3B/LC3B, microtubule-associated protein 1 light chain 3beta
- MP, melting point
- MTOR, mechanistic target of rapamycin
- NCI, National Cancer Institute
- NMR, nuclear magnetic resonance
- PLA2, phospholipase A2
- PVDF, polyvinylidene difluoride
- PtdIns3K, phosphatidylinositol 3-kinase class III
- PtdIns3P, phosphatidylinositol 3-phosphate
- RFP, red fluorescent protein
- RLU, relative luciferase units
- RPS6, ribosomal protein S6
- RPS6KB1, ribosomal protein S6 kinase, 70kDa, polypeptide 1
- SEM, standard error of the mean
- ULK1/2, unc-51-like autophagy activating kinase 1/2
- and xenografts
- antiautophagy compounds
- dNGLUC, Gaussia luciferase
- in silico docking
- osteosarcoma
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Affiliation(s)
- Debra Akin
- a Department of Anatomy and Cell Biology ; University of Florida ; Gainesville , FL USA
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Grasso S, Tristante E, Saceda M, Carbonell P, Mayor-López L, Carballo-Santana M, Carrasco-García E, Rocamora-Reverte L, García-Morales P, Carballo F, Ferragut JA, Martínez-Lacaci I. Resistance to Selumetinib (AZD6244) in colorectal cancer cell lines is mediated by p70S6K and RPS6 activation. Neoplasia 2014; 16:845-60. [PMID: 25379021 PMCID: PMC4212257 DOI: 10.1016/j.neo.2014.08.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/18/2014] [Accepted: 08/20/2014] [Indexed: 12/29/2022] Open
Abstract
Selumetinib (AZD6244, ARRY-142886) is a MEK1/2 inhibitor that has gained interest as an anti-tumour agent. We have determined the degree of sensitivity/resistance to Selumetinib in a panel of colorectal cancer cell lines using cell proliferation and soft agar assays. Sensitive cell lines underwent G1 arrest, whereas Selumetinib had no effect on the cell cycle of resistant cells. Some of the resistant cell lines showed high levels of ERK1/2 phosphorylation in the absence of serum. Selumetinib inhibited phosphorylation of ERK1/2 and RSK and had no effect on AKT phosphorylation in both sensitive and resistant cells. Furthermore, mutations in KRAS, BRAF, or PIK3CA were not clearly associated with Selumetinib resistance. Surprisingly, Selumetinib was able to inhibit phosphorylation of p70 S6 kinase (p70S6K) and its downstream target ribosomal protein S6 (RPS6) in sensitive cell lines. However, p70S6K and RPS6 phosphorylation remained unaffected or even increased in resistant cells. Moreover, in some of the resistant cell lines p70S6K and RPS6 were phosphorylated in the absence of serum. Interestingly, colorectal primary cultures derived from tumours excised to patients exhibited the same behaviour than established cell lines. Pharmacological inhibition of p70S6K using the PI3K/mTOR inhibitor NVP-BEZ235, the specific mTOR inhibitor Rapamycin and the specific p70S6K inhibitor PF-4708671 potentiated Selumetinib effects in resistant cells. In addition, biological inhibition of p70S6K using siRNA rendered responsiveness to Selumetinib in resistant cell lines. Furthermore, combination of p70S6K silencing and PF-47086714 was even more effective. We can conclude that p70S6K and its downstream target RPS6 are potential biomarkers of resistance to Selumetinib in colorectal cancer.
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Affiliation(s)
- Silvina Grasso
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain
| | - Elena Tristante
- Unidad AECC de Investigación Traslacional en Cáncer, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria, 30120 Murcia, Spain
| | - Miguel Saceda
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain ; Unidad de Investigación, Hospital General Universitario de Elche, 03203 Elche (Alicante), Spain
| | - Pablo Carbonell
- Centro de Bioquímica y Genética Clínica, Hospital Clínico Universitario Virgen de la Arrixaca, 30120 Murcia, Spain
| | - Leticia Mayor-López
- Unidad AECC de Investigación Traslacional en Cáncer, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria, 30120 Murcia, Spain
| | - Mar Carballo-Santana
- Unidad AECC de Investigación Traslacional en Cáncer, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria, 30120 Murcia, Spain
| | - Estefanía Carrasco-García
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain
| | - Lourdes Rocamora-Reverte
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain
| | - Pilar García-Morales
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain ; Unidad de Investigación, Hospital General Universitario de Elche, 03203 Elche (Alicante), Spain
| | - Fernando Carballo
- Unidad AECC de Investigación Traslacional en Cáncer, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria, 30120 Murcia, Spain ; Servicio de Gastroenterología, Hospital Clínico Universitario Virgen de la Arrixaca, 30120 Murcia, Spain
| | - José A Ferragut
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain
| | - Isabel Martínez-Lacaci
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, 03202 Elche (Alicante), Spain ; Unidad AECC de Investigación Traslacional en Cáncer, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria, 30120 Murcia, Spain
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