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Zappelli E, Daniele S, Ceccarelli L, Vergassola M, Ragni L, Mangano G, Martini C. α-glyceryl-phosphoryl-ethanolamine protects human hippocampal neurons from aging-induced cellular alterations. Eur J Neurosci 2022; 56:4514-4528. [PMID: 35902984 PMCID: PMC9545488 DOI: 10.1111/ejn.15783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 07/11/2022] [Accepted: 07/25/2022] [Indexed: 11/26/2022]
Abstract
Brain ageing has been related to a decrease in cellular metabolism, to an accumulation of misfolded proteins and to an alteration of the lipid membrane composition. These alterations act as contributive aspects of age‐related memory decline by reducing membrane excitability and neurotransmitter release. In this sense, precursors of phospholipids (PLs) can restore the physiological composition of cellular membranes and ameliorate the cellular defects associated with brain ageing. In particular, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) have been shown to restore mitochondrial function, reduce the accumulation of amyloid beta (Aβ) and, at the same time, provide the amount of acetylcholine needed to reduce memory deficit. Among PL precursors, alpha‐glycerylphosphorylethanolamine (GPE) has shown to protect astrocytes from Aβ injuries and to slow‐down ageing of human neural stem cells. GPE has been evaluated in aged human hippocampal neurons, which are implicated in learning and memory, and constitute a good in vitro model to investigate the beneficial properties of GPE. In order to mimic cellular ageing, the cells have been maintained 21 days in vitro and challenged with GPE. Results of the present paper showed GPE ability to increase PE and PC content, glucose uptake and the activity of the chain respiratory complex I and of the GSK‐3β pathway. Moreover, the nootropic compound showed an increase in the transcriptional/protein levels of neurotrophic and well‐being related genes. Finally, GPE counteracted the accumulation of ageing‐related misfolded proteins (a‐synuclein and tau). Overall, our data underline promising effects of GPE in counteracting cellular alterations related to brain ageing and cognitive decline.
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Affiliation(s)
| | | | | | | | - Lorella Ragni
- Global R&D PLCM -Angelini Pharma S.p.A, Ancona, Italy
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Sawano S, Kobayashi Y, Maesawa S, Mizunoya W. Egg components reverse the atrophy induced by injury in skeletal muscles. Genes Cells 2021; 27:138-144. [PMID: 34929062 DOI: 10.1111/gtc.12915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/26/2021] [Accepted: 12/10/2021] [Indexed: 11/29/2022]
Abstract
Skeletal muscle atrophy is the loss of muscle tissue caused by factors such as inactivity, malnutrition, aging, and injury. In this study, we aimed to investigate whether egg components exert inhibitory effects on muscle atrophy. An egg mix solution was orally administered for 10 consecutive days to male C57BL/6J mice injected with cardiotoxin in the tibialis anterior (TA) muscle. The administration of egg mixture significantly decreased the atrogin-1 and MuRF-1 protein levels, key factors in muscle atrophy, as observed by western blotting. Furthermore, we investigated the effects of egg components such as avidin, lecithin, biotin, 3-sn-phosphatidylcholine, and L-α-phosphatidylcholine on dexamethasone (DEX)-treated C2C12 myotubes. Lecithin, biotin, 3-sn-phosphatidylcholine, and L-α-phosphatidylcholine in egg yolk significantly recovered the diameters of C2C12 myotubes decreased upon DEX application. Avidin did not show such reversal. Biotin, 3-sn-phosphatidylcholine, and L-α-phosphatidylcholine also attenuated atrogin-1 protein expression enhanced by DEX. Our findings reveal that egg yolk components could contribute to the reversal of skeletal muscle atrophy induced by muscle injury.
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Affiliation(s)
- Shoko Sawano
- Department of Food and Life Science, School of Life and Environmental Science, Azabu University, Sagamihara, 252-5201, Japan
| | - Yuya Kobayashi
- Department of Food and Life Science, School of Life and Environmental Science, Azabu University, Sagamihara, 252-5201, Japan
| | - Suzuka Maesawa
- Department of Food and Life Science, School of Life and Environmental Science, Azabu University, Sagamihara, 252-5201, Japan
| | - Wataru Mizunoya
- Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, 252-5201, Japan
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Haslam DE, Liang L, Wang DD, Kelly RS, Wittenbecher C, Pérez CM, Martínez M, Lee CH, Clish CB, Wong DTW, Parnell LD, Lai CQ, Ordovás JM, Manson JE, Hu FB, Stampfer MJ, Tucker KL, Joshipura KJ, Bhupathiraju SN. Associations of network-derived metabolite clusters with prevalent type 2 diabetes among adults of Puerto Rican descent. BMJ Open Diabetes Res Care 2021; 9:9/1/e002298. [PMID: 34413117 PMCID: PMC8378385 DOI: 10.1136/bmjdrc-2021-002298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 07/25/2021] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION We investigated whether network analysis revealed clusters of coregulated metabolites associated with prevalent type 2 diabetes (T2D) among Puerto Rican adults. RESEARCH DESIGN AND METHODS We used liquid chromatography-mass spectrometry to measure fasting plasma metabolites (>600) among participants aged 40-75 years in the Boston Puerto Rican Health Study (BPRHS; discovery) and San Juan Overweight Adult Longitudinal Study (SOALS; replication), with (n=357; n=77) and without (n=322; n=934) T2D, respectively. Among BPRHS participants, we used unsupervised partial correlation network-based methods to identify and calculate metabolite cluster scores. Logistic regression was used to assess cross-sectional associations between metabolite clusters and prevalent T2D at the baseline blood draw in the BPRHS, and significant associations were replicated in SOALS. Inverse-variance weighted random-effect meta-analysis was used to combine cohort-specific estimates. RESULTS Six metabolite clusters were significantly associated with prevalent T2D in the BPRHS and replicated in SOALS (false discovery rate (FDR) <0.05). In a meta-analysis of the two cohorts, the OR and 95% CI (per 1 SD increase in cluster score) for prevalent T2D were as follows for clusters characterized primarily by glucose transport (0.21 (0.16 to 0.30); FDR <0.0001), sphingolipids (0.40 (0.29 to 0.53); FDR <0.0001), acyl cholines (0.35 (0.22 to 0.56); FDR <0.0001), sugar metabolism (2.28 (1.68 to 3.09); FDR <0.0001), branched-chain and aromatic amino acids (2.22 (1.60 to 3.08); FDR <0.0001), and fatty acid biosynthesis (1.54 (1.29 to 1.85); FDR <0.0001). Three additional clusters characterized by amino acid metabolism, cell membrane components, and aromatic amino acid metabolism displayed significant associations with prevalent T2D in the BPRHS, but these associations were not replicated in SOALS. CONCLUSIONS Among Puerto Rican adults, we identified several known and novel metabolite clusters that associated with prevalent T2D.
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Affiliation(s)
- Danielle E Haslam
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Nutrition, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
| | - Liming Liang
- Biostatistics, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
- Epidemiology, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
| | - Dong D Wang
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Nutrition, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
| | - Rachel S Kelly
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Cynthia M Pérez
- Department of Biostatistics and Epidemiology, Graduate School of Public Health, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Marijulie Martínez
- Center for Clinical Research and Health Promotion, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Chih-Hao Lee
- Molecular Metabolism, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
| | - Clary B Clish
- Metabolomics Platform, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - David T W Wong
- Center for Oral/Head and Neck Oncology Research, School of Dentistry, University of California Los Angeles, Los Angeles, California, USA
| | - Laurence D Parnell
- Agricultural Research Service, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts, USA
| | - Chao-Qiang Lai
- Agricultural Research Service, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts, USA
| | - José M Ordovás
- IMDEA-Food Institute, CEI UAM+CSIC, Madrid, Spain
- Nutrition and Genomics, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts, USA
| | - JoAnn E Manson
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Epidemiology, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
- Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Frank B Hu
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Nutrition, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
- Epidemiology, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
| | - Meir J Stampfer
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Nutrition, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
- Epidemiology, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
| | - Katherine L Tucker
- Department of Biomedical and Nutritional Sciences and Center for Population Health, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Kaumudi J Joshipura
- Epidemiology, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
- Center for Clinical Research and Health Promotion, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Shilpa N Bhupathiraju
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Nutrition, Harvard T H Chan School of Public Health, Boston, Massachusetts, USA
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Babenko NA, Kharchenko VS. Modulation of Insulin Sensitivity of Hepatocytes by the Pharmacological Downregulation of Phospholipase D. Int J Endocrinol 2015; 2015:794838. [PMID: 26089893 PMCID: PMC4458285 DOI: 10.1155/2015/794838] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/30/2015] [Accepted: 05/11/2015] [Indexed: 12/13/2022] Open
Abstract
Background. The role of phospholipase D (PLD) as a positive modulator of glucose uptake activation by insulin in muscle and adipose cells has been demonstrated. The role of PLD in the regulation of glucose metabolism by insulin in the primary hepatocytes has been determined in this study. Methods. For this purpose, we studied effects of inhibitors of PLD on glucose uptake and glycogen synthesis stimulation by insulin. To determine the PLD activity, the method based on determination of products of transphosphatidylation reaction, phosphatidylethanol or phosphatidylbutanol, was used. Results. Inhibition of PLD by a general antagonist (1-butanol) or specific inhibitor, halopemide, or N-hexanoylsphingosine, or by cellular ceramides accumulated in doxorubicin-treated hepatocytes decreased insulin-stimulated glucose metabolism. Doxorubicin-induced hepatocytes resistance to insulin action could be abolished by inhibition of ceramide production. Halopemide could nullify this effect. Addition of propranolol, as well as inhibitors of phosphatidylinositol 3-kinase (PI3-kinase) (wortmannin, LY294002) or suppressors of Akt phosphorylation/activity, luteolin-7-O-glucoside or apigenin-7-O-glucoside, to the culture media could block cell response to insulin action. Conclusion. PLD plays an important role in the insulin signaling in the hepatocytes. PLD is activated downstream of PI3-kinase and Akt and is highly sensitive to ceramide content in the liver cells.
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Affiliation(s)
- Nataliya A. Babenko
- Department of Physiology of Ontogenesis, Biology Research Institute, Karazin Kharkov National University, Svobody Square 4, Kharkov 61022, Ukraine
- *Nataliya A. Babenko:
| | - Vitalina S. Kharchenko
- Department of Physiology of Ontogenesis, Biology Research Institute, Karazin Kharkov National University, Svobody Square 4, Kharkov 61022, Ukraine
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Haramizu S, Mori T, Yano M, Ota N, Hashizume K, Otsuka A, Hase T, Shimotoyodome A. Habitual exercise plus dietary supplementation with milk fat globule membrane improves muscle function deficits via neuromuscular development in senescence-accelerated mice. SPRINGERPLUS 2014; 3:339. [PMID: 25110626 PMCID: PMC4125610 DOI: 10.1186/2193-1801-3-339] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/26/2014] [Indexed: 01/11/2023]
Abstract
We examined the effects of habitual exercise plus nutritional intervention through consumption of milk fat globule membrane (MFGM), a milk component, on aging-related deficits in muscle mass and function in senescence-accelerated P1 mice. Combining wheel-running and MFGM (MFGMEx) intake significantly attenuated age-related declines in quadriceps muscle mass (control: 318 ± 6 mg; MFGMEx: 356 ± 9 mg; P < 0.05) and in contractile force (1.4-fold and 1.5-fold higher in the soleus and extensor digitorum longus muscles, respectively). Microarray analysis of genes in the quadriceps muscle revealed that MFGMEx stimulated neuromuscular development; this was supported by significantly increased docking protein-7 (Dok-7) and myogenin mRNA expression. Treatment of differentiating myoblasts with MFGM-derived phospholipid or sphingolipid fractions plus mechanical stretching also significantly increased Dok-7 mRNA expression. These findings suggest that habitual exercise plus dietary MFGM improves muscle function deficits through neuromuscular development, and that phospholipid and sphingolipid in MFGM contribute to its physiological actions.
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Affiliation(s)
- Satoshi Haramizu
- Biological Science Laboratories, Kao Corporation, Tochigi, Japan
| | - Takuya Mori
- Biological Science Laboratories, Kao Corporation, Tochigi, Japan
| | - Michiko Yano
- Biological Science Laboratories, Kao Corporation, Tochigi, Japan
| | - Noriyasu Ota
- Biological Science Laboratories, Kao Corporation, Tochigi, Japan
| | | | - Atsuko Otsuka
- Biological Science Laboratories, Kao Corporation, Tochigi, Japan
| | - Tadashi Hase
- Biological Science Laboratories, Kao Corporation, Tochigi, Japan
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Shaheen F, Grammatopoulos DK, Müller J, Zammit VA, Lehnert H. Extra-nuclear telomerase reverse transcriptase (TERT) regulates glucose transport in skeletal muscle cells. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1762-9. [PMID: 24970747 DOI: 10.1016/j.bbadis.2014.06.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/20/2014] [Accepted: 06/17/2014] [Indexed: 10/25/2022]
Abstract
Telomerase reverse transcriptase (TERT) is a key component of the telomerase complex. By lengthening telomeres in DNA strands, TERT increases senescent cell lifespan. Mice that lack TERT age much faster and exhibit age-related conditions such as osteoporosis, diabetes and neurodegeneration. Accelerated telomere shortening in both human and animal models has been documented in conditions associated with insulin resistance, including T2DM. We investigated the role of TERT, in regulating cellular glucose utilisation by using the myoblastoma cell line C2C12, as well as primary mouse and human skeletal muscle cells. Inhibition of TERT expression or activity by using siRNA (100nM) or specific inhibitors (100nM) reduced basal 2-deoxyglucose uptake by ~50%, in all cell types, without altering insulin responsiveness. In contrast, TERT over-expression increased glucose uptake by 3.25-fold. In C2C12 cells TERT protein was mostly localised intracellularly and stimulation of cells with insulin induced translocation to the plasma membrane. Furthermore, co-immunoprecipitation experiments in C2C12 cells showed that TERT was constitutively associated with glucose transporters (GLUTs) 1, 4 and 12 via an insulin insensitive interaction that also did not require intact PI3-K and mTOR pathways. Collectively, these findings identified a novel extra-nuclear function of TERT that regulates an insulin-insensitive pathway involved in glucose uptake in human and mouse skeletal muscle cells.
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Affiliation(s)
- Fozia Shaheen
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Dimitris K Grammatopoulos
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Jürgen Müller
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Victor A Zammit
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Hendrik Lehnert
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK; First Department of Medicine, University Hospital of Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
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7
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Montserrat N, Capilla E, Navarro I, Gutiérrez J. Metabolic Effects of Insulin and IGFs on Gilthead Sea Bream (Sparus aurata) Muscle Cells. Front Endocrinol (Lausanne) 2012; 3:55. [PMID: 22654873 PMCID: PMC3356123 DOI: 10.3389/fendo.2012.00055] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 03/30/2012] [Indexed: 11/15/2022] Open
Abstract
Primary cultures of gilthead sea bream myocytes were performed in order to examine the relative metabolic function of insulin compared with IGF-I and IGF-II (insulin-like growth factors, IGFs) at different stages in the cell culture. In these cells, the in vitro effects of insulin and IGFs on 2-deoxyglucose (2-DG) and l-alanine uptake were studied in both myocytes (day 4) and small myotubes (day 9). 2-DG uptake in gilthead sea bream muscle cells was increased in the presence of insulin and IGFs in a time dependent manner and along with muscle cell differentiation. On the contrary, l-alanine uptake was also stimulated by insulin and IGFs but showed an inverse pattern, being the uptake higher in small myocytes than in large myotubes. The results of preincubation with inhibitors (PD-98059, wortmannin, and cytochalasin B) on 2-DG uptake indicated that insulin and IGFs stimulate glucose uptake through the same mechanisms, and evidenced that mitogenesis activator protein kinase (MAPK) and PI3K-Akt transduction pathways mediate the metabolic function of these peptides. In the same way, we observed that GLUT4 protein synthesis was stimulated in the presence of insulin and IGFs in gilthead sea bream muscle cells in a different manner at days 4 or 9 of the culture. In summary we describe here, for the first time, the effects of insulin and IGFs on 2-DG and l-alanine uptake in primary culture of gilthead sea bream muscle cells. We show that both MAPK and PI3K-Akt transduction pathways are needed in order to control insulin and IGFs actions in these cells. Moreover, changes in glucose uptake can be explained by the action of the GLUT4 transporter, which is stimulated in the presence of insulin and IGFs throughout the cell culture.
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Affiliation(s)
- Núria Montserrat
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de BarcelonaBarcelona, Spain
| | - Encarnación Capilla
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de BarcelonaBarcelona, Spain
| | - Isabel Navarro
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de BarcelonaBarcelona, Spain
| | - Joaquim Gutiérrez
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de BarcelonaBarcelona, Spain
- *Correspondence: Joaquim Gutiérrez, Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028 Barcelona, Spain. e-mail:
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Wang Y, Van Oort MM, Yao M, Van der Horst DJ, Rodenburg KW. Insulin and chromium picolinate induce translocation of CD36 to the plasma membrane through different signaling pathways in 3T3-L1 adipocytes, and with a differential functionality of the CD36. Biol Trace Elem Res 2011; 142:735-47. [PMID: 20721637 DOI: 10.1007/s12011-010-8809-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 08/06/2010] [Indexed: 01/09/2023]
Abstract
Chromium picolinate (CrPic) has been indicated to activate glucose transporter 4 (GLUT4) trafficking to the plasma membrane (PM) to enhance glucose uptake in 3T3-L1 adipocytes. In skeletal and heart muscle cells, insulin directs the intracellular trafficking of the fatty acid translocase/CD36 to induce the uptake of cellular long-chain fatty acid (LCFA). The current study describes the effects of CrPic and insulin on the translocation of CD36 from intracellular storage pools to the PM in 3T3-L1 adipocytes in comparison with that of GLUT4. Immunofluorescence microscopy and immunoblotting revealed that both CD36 and GLUT4 were expressed and primarily located intracellularly in 3T3-L1 adipocytes. Upon insulin or CrPic stimulation, PM expression of CD36 increased in a similar manner as that for GLUT4; the CrPic-stimulated PM expression was less strong than that of insulin. The increase in PM localization for these two proteins by insulin paralleled LCFA ([1-(14)C]palmitate) or [(3)H]deoxyglucose uptake in 3T3-L1 adipocytes. The induction of the PM expression of GLUT4, but not CD36, or substrate uptake by insulin and CrPic appears to be additive in adipocytes. Furthermore, wortmannin completely inhibited the insulin-stimulated translocation of GLUT4 or CD36 and prevented the increased uptake of glucose or LCFA in these cells. Taken together, for the first time, these findings suggest that both insulin and CrPic induce CD36 translocation to the PM in 3T3-L1 adipocytes and that their translocation-inducing effects are not additive. The signaling pathway inducing the translocations is different, apparently resulting in a differential activity of CD36.
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Affiliation(s)
- Yiqun Wang
- Department of Pharmacology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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Oliveira TG, Di Paolo G. Phospholipase D in brain function and Alzheimer's disease. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:799-805. [PMID: 20399893 DOI: 10.1016/j.bbalip.2010.04.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 04/07/2010] [Accepted: 04/08/2010] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease is the most common neurodegenerative disorder. Although lipids are major constituents of brain, their role in Alzheimer's disease pathogenesis is poorly understood. Much attention has been given to cholesterol, but growing evidence suggests that other lipids, such as phospholipids, might play an important role in this disorder. In this review, we will summarize the evidence linking phospholipase D, a phosphatidic acid-synthesizing enzyme, to multiple aspects of normal brain function and to Alzheimer's disease. The role of phospholipase D in signaling mechanisms downstream of beta-amyloid as well as in the trafficking and processing of amyloid precursor protein will be emphasized.
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Affiliation(s)
- Tiago Gil Oliveira
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
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Konig S, Béguet A, Bader CR, Bernheim L. The calcineurin pathway links hyperpolarization (Kir2.1)-induced Ca2+ signals to human myoblast differentiation and fusion. Development 2006; 133:3107-14. [PMID: 16831831 DOI: 10.1242/dev.02479] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In human myoblasts triggered to differentiate, a hyperpolarization, resulting from K+ channel (Kir2.1) activation, allows the generation of an intracellular Ca2+ signal. This signal induces an increase in expression/activity of two key transcription factors of the differentiation process, myogenin and MEF2. Blocking hyperpolarization inhibits myoblast differentiation. The link between hyperpolarization-induced Ca2+ signals and the four main regulatory pathways involved in myoblast differentiation was the object of this study. Of the calcineurin, p38-MAPK, PI3K and CaMK pathways, only the calcineurin pathway was inhibited when Kir2.1-linked hyperpolarization was blocked. The CaMK pathway, although Ca2+ dependent, is unaffected by changes in membrane potential or block of Kir2.1 channels. Concerning the p38-MAPK and PI3K pathways, their activity is present already in proliferating myoblasts and they are unaffected by hyperpolarization or Kir2.1 channel block. We conclude that the Kir2.1-induced hyperpolarization triggers human myoblast differentiation via the activation of the calcineurin pathway, which, in turn, induces expression/activity of myogenin and MEF2.
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Affiliation(s)
- Stéphane Konig
- Department of Clinical Neurosciences, University Hospital, Geneva, Switzerland.
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