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Madureira TV, Pinheiro I, Malhão F, Lopes C, Urbatzka R, Castro LFC, Rocha E. Cross-interference of two model peroxisome proliferators in peroxisomal and estrogenic pathways in brown trout hepatocytes. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 187:153-162. [PMID: 28415051 DOI: 10.1016/j.aquatox.2017.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 03/16/2017] [Accepted: 04/04/2017] [Indexed: 06/07/2023]
Abstract
Peroxisome proliferators cause species-specific effects, which seem to be primarily transduced by peroxisome proliferator-activated receptor alpha (PPARα). Interestingly, PPARα has a close interrelationship with estrogenic signaling, and this latter has already been promptly activated in brown trout primary hepatocytes. Thus, and further exploring this model, we assess here the reactivity of two PPARα agonists in direct peroxisomal routes and, in parallel the cross-interferences in estrogen receptor (ER) mediated paths. To achieve these goals, three independent in vitro studies were performed using single exposures to clofibrate - CLF (50, 500 and 1000μM), Wy-14,643 - Wy (50 and 150μM), GW6471 - GW (1 and 10μM), and mixtures, including PPARα agonist or antagonist plus an ER agonist or antagonist. Endpoints included gene expression analysis of peroxisome/lipidic related genes (encoding apolipoprotein AI - ApoAI, fatty acid binding protein 1 - Fabp1, catalase - Cat, 17 beta-hydroxysteroid dehydrogenase 4 - 17β-HSD4, peroxin 11 alpha - Pex11α, PPARαBb, PPARαBa and urate oxidase - Uox) and those encoding estrogenic targets (ERα, ERβ-1 and vitellogenin A - VtgA). A quantitative morphological approach by using a pre-validated catalase immunofluorescence technique allowed checking possible changes in peroxisomes. Our results show a low responsiveness of trout hepatocytes to model PPARα agonists in direct target receptor pathways. Additionally, we unveiled interferences in estrogenic signaling caused by Wy, leading to an up-regulation VtgA and ERα at 150μM; these effects seem counteracted with a co-exposure to an ER antagonist. The present data stress the potential of this in vitro model for further exploring the physiological/toxicological implications related with this nuclear receptor cross-regulation.
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Affiliation(s)
- Tânia Vieira Madureira
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal.
| | - Ivone Pinheiro
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal
| | - Fernanda Malhão
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal
| | - Célia Lopes
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal
| | - Ralph Urbatzka
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - L Filipe C Castro
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Faculty of Sciences (FCUP), University of Porto (U. Porto), Department of Biology, Rua do Campo Alegre, P 4169-007 Porto, Portugal
| | - Eduardo Rocha
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal
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Mycobacteria modulate host epigenetic machinery by Rv1988 methylation of a non-tail arginine of histone H3. Nat Commun 2015; 6:8922. [DOI: 10.1038/ncomms9922] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 10/12/2015] [Indexed: 12/11/2022] Open
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Wang G, Bonkovsky HL, de Lemos A, Burczynski FJ. Recent insights into the biological functions of liver fatty acid binding protein 1. J Lipid Res 2015; 56:2238-47. [PMID: 26443794 DOI: 10.1194/jlr.r056705] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Indexed: 12/18/2022] Open
Abstract
Over four decades have passed since liver fatty acid binding protein (FABP)1 was first isolated. There are few protein families for which most of the complete tertiary structures, binding properties, and tissue occurrences are described in such detail and yet new functions are being uncovered for this protein. FABP1 is known to be critical for fatty acid uptake and intracellular transport and also has an important role in regulating lipid metabolism and cellular signaling pathways. FABP1 is an important endogenous cytoprotectant, minimizing hepatocyte oxidative damage and interfering with ischemia-reperfusion and other hepatic injuries. The protein may be targeted for metabolic activation through the cross-talk among many transcriptional factors and their activating ligands. Deficiency or malfunction of FABP1 has been reported in several diseases. FABP1 also influences cell proliferation during liver regeneration and may be considered as a prognostic factor for hepatic surgery. FABP1 binds and modulates the action of many molecules such as fatty acids, heme, and other metalloporphyrins. The ability to bind heme is another cytoprotective property and one that deserves closer investigation. The role of FABP1 in substrate availability and in protection from oxidative stress suggests that FABP1 plays a pivotal role during intracellular bacterial/viral infections by reducing inflammation and the adverse effects of starvation (energy deficiency).
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Affiliation(s)
- GuQi Wang
- Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China Department of Biology, University of North Carolina at Charlotte, Charlotte, NC Carolinas HealthCare System, Charlotte, NC
| | - Herbert L Bonkovsky
- Department of Biology, University of North Carolina at Charlotte, Charlotte, NC Carolinas HealthCare System, Charlotte, NC Wake Forest Baptist Medical Center, Winston-Salem, NC
| | - Andrew de Lemos
- Carolinas HealthCare System, Charlotte, NC Wake Forest Baptist Medical Center, Winston-Salem, NC
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Kajimoto K, Minami Y, Harashima H. Cytoprotective role of the fatty acid binding protein 4 against oxidative and endoplasmic reticulum stress in 3T3-L1 adipocytes. FEBS Open Bio 2014; 4:602-10. [PMID: 25161868 PMCID: PMC4141204 DOI: 10.1016/j.fob.2014.06.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 06/20/2014] [Accepted: 06/30/2014] [Indexed: 01/27/2023] Open
Abstract
Oxidative stress in 3T3-L1 adipocytes was elevated by silencing of FABP4. FABP4 silencing did not alter levels of glutathione or superoxide dismutase. The recombinant FABP4 significantly reduced levels of hydrogen peroxide. The resistance of adipocytes to oxidative stress was decreased by FABP4 knockdown. Silencing of FABP4 elevated the endoplasmic reticulum stress in adipocytes.
The fatty acid binding protein 4 (FABP4), one of the most abundant proteins in adipocytes, has been reported to have a proinflammatory function in macrophages. However, the physiological role of FABP4, which is constitutively expressed in adipocytes, has not been fully elucidated. Previously, we demonstrated that FABP4 was involved in the regulation of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) production in 3T3-L1 adipocytes. In this study, we examined the effects of FABP4 silencing on the oxidative and endoplasmic reticulum (ER) stress in 3T3-L1 adipocytes. We found that the cellular reactive oxygen species (ROS) and 8-nitro-cyclic GMP levels were significantly elevated in the differentiated 3T3-L1 adipocytes transfected with a small interfering RNA (siRNA) against Fabp4, although the intracellular levels or enzyme activities of antioxidants including reduced glutathione (GSH), superoxide dismutase (SOD) and glutathione S-transferase A4 (GSTA4) were not altered. An in vitro evaluation using the recombinant protein revealed that FABP4 itself functions as a scavenger protein against hydrogen peroxide (H2O2). FABP4-knockdown resulted in a significant lowering of cell viability of 3T3-L1 adipocytes against H2O2 treatment. Moreover, four kinds of markers related to the ER stress response including the endoplasmic reticulum to nucleus signaling 1 (Ern1), the signal sequence receptor α (Ssr1), the ORM1-like 3 (Ormdl3), and the spliced X-box binding protein 1 (Xbp1s), were all elevated as the result of the knockdown of FABP4. Consequently, FABP4 might have a new role as an antioxidant protein against H2O2 and contribute to cytoprotection against oxidative and ER stress in adipocytes.
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Key Words
- Adipocyte
- Antioxidant
- ER stress
- ER, endoplasmic reticulum
- Ern1, endoplasmic reticulum to nucleus signaling 1
- FABP, fatty acid binding protein
- FABP4
- GSH, reduced glutathione
- GSTA4, glutathione S-transferase A4
- H2O2, hydrogen peroxide
- Ormdl3, ORM1-like 3
- Oxidative stress
- ROS, reactive oxygen species
- SOD, superoxide dismutase
- Ssr1, signal sequence receptor α
- UPR, unfolded protein response
- VEGF, vascular endothelial growth factor
- Xbp1, X-box binding protein 1.
- siRNA, small interfering RNA
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Affiliation(s)
- Kazuaki Kajimoto
- Corresponding author. Tel.: +81 11 706 2197; fax: +81 11 706 4879.
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Jiao ZY, Wu J, Wen B, Zhao WZ, Du XL. M3 muscarinic acetylcholine receptor dysfunction inhibits Rac1 activity and disrupts VE-cadherin/β-catenin and actin cytoskeleton interaction. Biochem Cell Biol 2014; 92:137-44. [PMID: 24697698 DOI: 10.1139/bcb-2013-0042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The objective was to investigate whether M3 muscarinic acetylcholine receptor (mAChR) dysfunction disrupts the linkage between the vascular endothelial (VE)-cadherin in the adherens junctional complex and the actin-based cytoskeleton, increasing vascular permeability in atherosclerosis. Western blotting revealed that a selective M3 receptor antagonist, 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), and M3 receptor siRNA decrease VE-cadherin and β-catenin in Triton X-100-insoluble fractions, indicating that M3 receptor inhibition weakens the linkage between the VE-cadherin/β-catenin complex and the actin cytoskeleton. Co-immunoprecipitation assays showed that M3 receptor inhibition reduces Rac1 activity and the association of IQ motif-containing GTPase-activating protein 1 (IQGAP1) with Ras-related C3 botulinum toxin substrate 1 (Rac1), while increasing the interaction between IQGAP1 and β-catenin. Using IQGAP1 siRNA, we found that IQGAP1 is required for stable interaction between VE-cadherin/β-catenin and the actin cytoskeleton in quiescent endothelial cells; IQGAP1 siRNA augments the M3 receptor inhibition-induced dissociation between them. Moreover, S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor, attenuates this disassociation and Rac1 activity inhibition. The M3 receptor facilitates interaction of the VE-cadherin-based adherens junctional complex and the actin-based cytoskeleton by maintaining Rac1 activity, which regulates the interaction between IQGAP1/Rac1 and IQGAP1/β-catenin, and may contribute to endothelial barrier function under physiological conditions.
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Affiliation(s)
- Zhou-Yang Jiao
- a Department of Cardiovascular Surgery, Xiehe Hospital, Huazhong University of Science and Technology, Wuhan, 430022, China
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High glucose potentiates L-FABP mediated fibrate induction of PPARα in mouse hepatocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1412-25. [PMID: 23747828 DOI: 10.1016/j.bbalip.2013.05.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 05/17/2013] [Accepted: 05/30/2013] [Indexed: 01/22/2023]
Abstract
Although liver fatty acid binding protein (L-FABP) binds fibrates and PPARα in vitro and enhances fibrate induction of PPARα in transformed cells, the functional significance of these findings is unclear, especially in normal hepatocytes. Studies with cultured primary mouse hepatocytes show that: 1) At physiological (6mM) glucose, fibrates (bezafibrate, fenofibrate) only weakly activated PPARα transcription of genes in LCFA β-oxidation; 2) High (11-20mM) glucose, but not maltose (osmotic control), significantly potentiated fibrate-induction of mRNA of these and other PPARα target genes to increase LCFA β-oxidation. These effects were associated with fibrate-mediated redistribution of L-FABP into nuclei-an effect prolonged by high glucose-but not with increased de novo fatty acid synthesis from glucose; 3) Potentiation of bezafibrate action by high glucose required an intact L-FABP/PPARα signaling pathway as shown with L-FABP null, PPARα null, PPARα inhibitor-treated WT, or PPARα-specific fenofibrate-treated WT hepatocytes. High glucose alone in the absence of fibrate was ineffective. Thus, high glucose potentiation of PPARα occurred through FABP/PPARα rather than indirectly through other PPARs or glucose induced signaling pathways. These data indicated L-FABP's importance in fibrate-induction of hepatic PPARα LCFA β-oxidative genes, especially in the context of high glucose levels.
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Petrescu AD, Huang H, Martin GG, McIntosh AL, Storey SM, Landrock D, Kier AB, Schroeder F. Impact of L-FABP and glucose on polyunsaturated fatty acid induction of PPARα-regulated β-oxidative enzymes. Am J Physiol Gastrointest Liver Physiol 2013; 304:G241-56. [PMID: 23238934 PMCID: PMC3566512 DOI: 10.1152/ajpgi.00334.2012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Liver fatty acid binding protein (L-FABP) is the major soluble protein that binds very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) in hepatocytes. However, nothing is known about L-FABP's role in n-3 PUFA-mediated peroxisome proliferator activated receptor-α (PPARα) transcription of proteins involved in long-chain fatty acid (LCFA) β-oxidation. This issue was addressed in cultured primary hepatocytes from wild-type, L-FABP-null, and PPARα-null mice with these major findings: 1) PUFA-mediated increase in the expression of PPARα-regulated LCFA β-oxidative enzymes, LCFA/LCFA-CoA binding proteins (L-FABP, ACBP), and PPARα itself was L-FABP dependent; 2) PPARα transcription, robustly potentiated by high glucose but not maltose, a sugar not taken up, correlated with higher protein levels of these LCFA β-oxidative enzymes and with increased LCFA β-oxidation; and 3) high glucose altered the potency of n-3 relative to n-6 PUFA. This was not due to a direct effect of glucose on PPARα transcriptional activity nor indirectly through de novo fatty acid synthesis from glucose. Synergism was also not due to glucose impacting other signaling pathways, since it was observed only in hepatocytes expressing both L-FABP and PPARα. Ablation of L-FABP or PPARα as well as treatment with MK886 (PPARα inhibitor) abolished/reduced PUFA-mediated PPARα transcription of these genes, especially at high glucose. Finally, the PUFA-enhanced L-FABP distribution into nuclei with high glucose augmentation of the L-FABP/PPARα interaction reveals not only the importance of L-FABP for PUFA induction of PPARα target genes in fatty acid β-oxidation but also the significance of a high glucose enhancement effect in diabetes.
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Affiliation(s)
- Anca D. Petrescu
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
| | - Huan Huang
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
| | - Gregory G. Martin
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
| | - Avery L. McIntosh
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
| | - Stephen M. Storey
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
| | - Danilo Landrock
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
| | - Ann B. Kier
- 2Department of Pathobiology, Texas A&M University, TVMC, College Station, Texas
| | - Friedhelm Schroeder
- 1Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, Texas; and
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