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Kann O, Almouhanna F, Chausse B. Interferon γ: a master cytokine in microglia-mediated neural network dysfunction and neurodegeneration. Trends Neurosci 2022; 45:913-927. [PMID: 36283867 DOI: 10.1016/j.tins.2022.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/30/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
Traditionally, lymphocytic interferon γ (IFN-γ) was considered to be a simple 'booster' of proinflammatory responses by microglia (brain-resident macrophages) during bacterial or viral infection. Recent slice culture (in situ) and in vivo studies suggest, however, that IFN-γ has a unique role in microglial activation. Priming by IFN-γ results in proliferation (microgliosis), enhanced synapse elimination, and moderate nitric oxide release sufficient to impair synaptic transmission, gamma rhythm activity, and cognitive functions. Moreover, IFN-γ is pivotal for driving Toll-like receptor (TLR)-activated microglia into neurotoxic phenotypes that induce energetic and oxidative stress, severe network dysfunction, and neuronal death. Pharmacological targeting of activated microglia could be beneficial during elevated IFN-γ levels, blood-brain barrier leakage, and parenchymal T lymphocyte infiltration associated with, for instance, encephalitis, multiple sclerosis, and Alzheimer's disease.
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Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, D-69120 Heidelberg, Germany.
| | - Fadi Almouhanna
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
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Schilling S, Chausse B, Dikmen HO, Almouhanna F, Hollnagel JO, Lewen A, Kann O. TLR2- and TLR3-activated microglia induce different levels of neuronal network dysfunction in a context-dependent manner. Brain Behav Immun 2021; 96:80-91. [PMID: 34015428 DOI: 10.1016/j.bbi.2021.05.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 05/11/2021] [Accepted: 05/15/2021] [Indexed: 02/06/2023] Open
Abstract
Recognition of pathogen- or damage-associated molecular patterns (PAMPs, DAMPs) by innate Toll-like receptors (TLRs) is central to the activation of microglia (brain macrophages) in many CNS diseases. Notably, TLR-mediated microglial activation is complex and modulated by additional exogenous and endogenous immunological signals. The impact of different microglial reactive phenotypes on electrical activity and neurotransmission is widely unknown, however. We explored the effects of TLR ligands on microglia and neuronal network function in rat organotypic hippocampal slice cultures (in situ), i.e., postnatal cortical tissue lacking adaptive immunity. Single exposure of slice cultures to TLR2 or TLR3 ligands [PGN, poly(I:C)] for 2-3 days induced moderate microglial activation featuring IL-6 and TNF-α release and only mild alterations of fast neuronal gamma band oscillations (30-70 Hz) that are fundamental to higher cognitive functions, such as perception, memory and behavior. Paired exposure to TLR3/TLR2 or TLR3/TLR4 ligands (LPS) induced nitric oxide (NO) release, enhanced TNF-α release, and associated with advanced network dysfunction, including slowing to the beta frequency band (12-30 Hz) and neural bursts (hyperexcitability). Paired exposure to a TLR ligand and the leukocyte cytokine IFN-γ enhanced NO release and associated with severe network dysfunction, albeit sensitive parvalbumin- and somatostatin-positive inhibitory interneurons were preserved. Notably, the neuronal disturbance was prevented by either microglial depletion or pharmacological inhibition of oxidant-producing enzymes, inducible NO synthase (iNOS) and NADPH oxidase. In conclusion, TLR-activated microglia can induce different levels of neuronal network dysfunction, in which severe dysfunction is mainly caused by reactive oxygen and nitrogen species rather than proinflammatory cytokines. Our findings provide a mechanistic insight into microglial activation and functional neuronal network impairment, with relevance to neuroinflammation and neurodegeneration observed in, e.g., meningoencephalitis, multiple sclerosis and Alzheimer's disease.
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Affiliation(s)
- Simone Schilling
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Hasan Onur Dikmen
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Fadi Almouhanna
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, D-69120 Heidelberg, Germany.
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Raposo HF, Forsythe P, Chausse B, Castelli JZ, Moraes-Vieira PM, Nunes VS, Oliveira HCF. Novel role of cholesteryl ester transfer protein (CETP): attenuation of adiposity by enhancing lipolysis and brown adipose tissue activity. Metabolism 2021; 114:154429. [PMID: 33166579 DOI: 10.1016/j.metabol.2020.154429] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/13/2020] [Accepted: 11/04/2020] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The systemic function of CETP has been well characterized. CETP plasma activity reduces HDL cholesterol and thus increases the risk of atherosclerosis. Here, we investigated whether CETP expression modulate adiposity. METHODS Body adiposity and energy metabolism related assays and gene/protein expression were compared in CETP transgenic and non-transgenic mice and in hamsters treated with CETP neutralizing antibody. RESULTS We found that transgenic mice expressing human CETP present less white adipose tissue mass and lower leptinemia than nontransgenic (NTg) littermates. No differences were found in physical activity, food intake, fat fecal excretion, lipogenesis or exogenous lipid accumulation in adipose depots. Nonetheless, adipose lipolysis rates and whole-body energy expenditure were elevated in CETP mice. In accordance, lipolysis-related gene expression and protein content were increased in visceral and brown adipose tissue (BAT). In addition, we verified increased BAT temperature and oxygen consumption. These results were confirmed in two other animal models: 1) hamsters treated with CETP neutralizing antibody and 2) an independent line of transgenic mice expressing simian CETP. CONCLUSIONS These findings reveal a novel anti-adipogenic role for CETP.
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Affiliation(s)
- Helena F Raposo
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Patricia Forsythe
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Bruno Chausse
- Obesity and Comorbidities Research Center, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Júlia Z Castelli
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Pedro M Moraes-Vieira
- Obesity and Comorbidities Research Center, Institute of Biology, State University of Campinas, Campinas, SP, Brazil; Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil; Experimental Medicine Research Cluster (EMRC), State University of Campinas, SP, Brazil
| | - Valéria S Nunes
- Laboratorio de Lipides (LIM10), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Helena C F Oliveira
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil; Obesity and Comorbidities Research Center, Institute of Biology, State University of Campinas, Campinas, SP, Brazil.
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Chausse B, Kakimoto PA, Kann O. Microglia and lipids: how metabolism controls brain innate immunity. Semin Cell Dev Biol 2020; 112:137-144. [PMID: 32807643 DOI: 10.1016/j.semcdb.2020.08.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/31/2020] [Accepted: 08/01/2020] [Indexed: 12/26/2022]
Abstract
Microglia are universal sensors of alterations in CNS physiology. These cells integrate complex molecular signals and undergo comprehensive phenotypical remodeling to adapt inflammatory responses. In the last years, single-cell analyses have revealed that microglia exhibit diverse phenotypes during development, growth and disease. Emerging evidence suggests that such phenotype transitions are mediated by reprogramming of cell metabolism. Indeed, metabolic pathways are distinctively altered in activated microglia and are central nodes controlling microglial responses. Microglial lipid metabolism has been specifically involved in the control of microglial activation and effector functions, such as migration, phagocytosis and inflammatory signaling, and minor disturbances in microglial lipid handling associates with altered brain function in disorders featuring neuroinflammation. In this review, we explore new and relevant aspects of microglial metabolism in health and disease. We give special focus on how different branches of lipid metabolism, such as lipid sensing, synthesis and oxidation, integrate and control essential aspects of microglial biology, and how disturbances in these processes associate with aging and the pathogenesis of, for instance, multiple sclerosis and Alzheimer's disease. Finally, challenges and advances in microglial lipid research are discussed.
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Affiliation(s)
- Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany.
| | - Pamela A Kakimoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, Brazil
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences, University of Heidelberg, D-69120 Heidelberg, Germany
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Dikmen HO, Hemmerich M, Lewen A, Hollnagel JO, Chausse B, Kann O. GM-CSF induces noninflammatory proliferation of microglia and disturbs electrical neuronal network rhythms in situ. J Neuroinflammation 2020; 17:235. [PMID: 32782006 PMCID: PMC7418331 DOI: 10.1186/s12974-020-01903-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [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: 04/08/2020] [Accepted: 07/16/2020] [Indexed: 12/19/2022] Open
Abstract
Background The granulocyte-macrophage colony-stimulating factor (GM-CSF) (or CSF-2) is involved in myeloid cell growth and differentiation, and, possibly, a major mediator of inflammation in body tissues. The role of GM-CSF in the activation of microglia (CNS resident macrophages) and the consequent impacts on neuronal survival, excitability, and synaptic transmission are widely unknown, however. Here, we focused on electrical neuronal network rhythms in the gamma frequency band (30–70 Hz). Gamma oscillations are fundamental to higher brain functions, such as perception, attention, and memory, and they are exquisitely sensitive to metabolic and oxidative stress. Methods We explored the effects of chronic GM-CSF exposure (72 h) on microglia in male rat organotypic hippocampal slice cultures (in situ), i.e., postnatal cortex tissue lacking leukocyte invasion (adaptive immunity). We applied extracellular electrophysiological recordings of local field potential, immunohistochemistry, design-based stereology, biochemical analysis, and pharmacological ablation of microglia. Results GM-CSF triggered substantial proliferation of microglia (microgliosis). By contrast, the release of proinflammatory cytokines (IL-6, TNF-α) and nitric oxide, the hippocampal cytoarchitecture as well as the morphology of parvalbumin-positive inhibitory interneurons were unaffected. Notably, GM-CSF induced concentration-dependent, long-lasting disturbances of gamma oscillations, such as slowing (beta frequency band) and neural burst firing (hyperexcitability), which were not mimicked by the T lymphocyte cytokine IL-17. These disturbances were attenuated by depletion of the microglial cell population with liposome-encapsulated clodronate. In contrast to priming with the cytokine IFN-γ (type II interferon), GM-CSF did not cause inflammatory neurodegeneration when paired with the TLR4 ligand LPS. Conclusions GM-CSF has a unique role in the activation of microglia, including the potential to induce neuronal network dysfunction. These immunomodulatory properties might contribute to cognitive impairment and/or epileptic seizure development in disease featuring elevated GM-CSF levels, blood-brain barrier leakage, and/or T cell infiltration.
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Affiliation(s)
- Hasan Onur Dikmen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Marc Hemmerich
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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Lewen A, Ta TT, Cesetti T, Hollnagel JO, Papageorgiou IE, Chausse B, Kann O. Neuronal gamma oscillations and activity-dependent potassium transients remain regular after depletion of microglia in postnatal cortex tissue. J Neurosci Res 2020; 98:1953-1967. [PMID: 32638411 DOI: 10.1002/jnr.24689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/28/2022]
Abstract
Microglial cells (resident macrophages) feature rapid activation in CNS disease and can acquire multiple phenotypes exerting neuroprotection or neurotoxicity. The functional impact of surveying ("resting") microglia on neural excitability and neurotransmission in physiology is widely unknown, however. We addressed this issue in male rat hippocampal slice cultures (in situ) by pharmacological microglial ablation within days and by characterizing neuronal gamma-band oscillations (30-70 Hz) that are highly sensitive to neuromodulators and disturbances in ion and energy regulation. Gamma oscillations support action potential timing and synaptic plasticity, associate with higher brain functions like perception and memory, and require precise communication between excitatory pyramidal cells and inhibitory (GABAergic) interneurons. The slice cultures featured well-preserved hippocampal cytoarchitecture and parvalbumin-positive interneuron networks, microglia with ramified morphology, and low basal levels of IL-6, TNF-α, and nitric oxide (NO). Stimulation of slice cultures with the pro-inflammatory cytokine IFN-γ or bacterial LPS serving as positive controls for microglial reactivity induced MHC-II expression and increased cytokine and NO release. Chronic exposure of slice cultures to liposome-encapsulated clodronate reduced the microglial cell population by about 96%, whereas neuronal structures, astrocyte GFAP expression, and basal levels of cytokines and NO were unchanged. Notably, the properties of gamma oscillations reflecting frequency, number and synchronization of synapse activity were regular after microglial depletion. Also, electrical stimulus-induced transients of the extracellular potassium concentration ([K+ ]o ) reflecting cellular K+ efflux, clearance and buffering were unchanged. This suggests that nonreactive microglia are dispensable for neuronal homeostasis and neuromodulation underlying network signaling and rhythm generation in cortical tissue.
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Affiliation(s)
- Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Thuy-Truc Ta
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Tiziana Cesetti
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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Kakimoto PA, Chausse B, Caldeira da Silva CC, Donato Júnior J, Kowaltowski AJ. Resilient hepatic mitochondrial function and lack of iNOS dependence in diet-induced insulin resistance. PLoS One 2019; 14:e0211733. [PMID: 30716103 PMCID: PMC6361450 DOI: 10.1371/journal.pone.0211733] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/18/2019] [Indexed: 12/18/2022] Open
Abstract
Obesity-derived inflammation and metabolic dysfunction has been related to the activity of the inducible nitric oxide synthase (iNOS). To understand the interrelation between metabolism, obesity and NO., we evaluated the effects of obesity-induced NO. signaling on liver mitochondrial function. We used mouse strains containing mitochondrial nicotinamide transhydrogenase activity, while prior studies involved a spontaneous mutant of this enzyme, and are, therefore, more prone to oxidative imbalance. Wild-type and iNOS knockout mice were fed a high fat diet for 2, 4 or 8 weeks. iNOS knockout did not protect against diet-induced metabolic changes. However, the diet decreased fatty-acid oxidation capacity in liver mitochondria at 4 weeks in both wild-type and knockout groups; this was recovered at 8 weeks. Interestingly, other mitochondrial functional parameters were unchanged, despite significant modifications in insulin resistance in wild type and iNOS knockout animals. Overall, we found two surprising features of obesity-induced metabolic dysfunction: (i) iNOS does not have an essential role in obesity-induced insulin resistance under all experimental conditions and (ii) liver mitochondria are resilient to functional changes in obesity-induced metabolic dysfunction.
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Affiliation(s)
- Pamela A. Kakimoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
- * E-mail:
| | - Bruno Chausse
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - José Donato Júnior
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Alicia J. Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Carraro RS, Souza GF, Solon C, Razolli DS, Chausse B, Barbizan R, Victorio SC, Velloso LA. Hypothalamic mitochondrial abnormalities occur downstream of inflammation in diet-induced obesity. Mol Cell Endocrinol 2018; 460:238-245. [PMID: 28760600 DOI: 10.1016/j.mce.2017.07.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/27/2017] [Accepted: 07/27/2017] [Indexed: 10/19/2022]
Abstract
Hypothalamic dysfunction is a common feature of experimental obesity. Studies have identified at least three mechanisms involved in the development of hypothalamic neuronal defects in diet-induced obesity: i, inflammation; ii, endoplasmic reticulum stress; and iii, mitochondrial abnormalities. However, which of these mechanisms is activated earliest in response to the consumption of large portions of dietary fats is currently unknown. Here, we used immunoblot, real-time PCR, mitochondrial respiration assays and transmission electron microscopy to evaluate markers of inflammation, endoplasmic reticulum stress and mitochondrial abnormalities in the hypothalamus of Swiss mice fed a high-fat diet for up to seven days. In the present study we show that the expression of the inflammatory chemokine fractalkine was the earliest event detected. Its hypothalamic expression increased as early as 3 h after the introduction of a high-fat diet and was followed by the increase of cytokines. GPR78, an endoplasmic reticulum chaperone, was increased 6 h after the introduction of a high-fat diet, however the actual triggering of endoplasmic reticulum stress was only detected three days later, when IRE-1α was increased. Mitofusin-2, a protein involved in mitochondrial fusion and tethering of mitochondria to the endoplasmic reticulum, underwent a transient reduction 24 h after the introduction of a high-fat diet and then increased after seven days. There were no changes in hypothalamic mitochondrial respiration during the experimental period, however there were reductions in mitochondria/endoplasmic reticulum contact sites, beginning three days after the introduction of a high-fat diet. The inhibition of TNF-α with infliximab resulted in the normalization of mitofusin-2 levels 24 h after the introduction of the diet. Thus, inflammation is the earliest mechanism activated in the hypothalamus after the introduction of a high-fat diet and may play a mechanistic role in the development of mitochondrial abnormalities in diet-induced obesity.
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Affiliation(s)
- Rodrigo S Carraro
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil
| | - Gabriela F Souza
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil
| | - Carina Solon
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil
| | - Daniela S Razolli
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil
| | - Bruno Chausse
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil; Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil
| | - Roberta Barbizan
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil
| | - Sheila C Victorio
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil
| | - Licio A Velloso
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, University of Campinas, 13084-970 Campinas, SP, Brazil.
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Alsabeeh N, Chausse B, Kakimoto PA, Kowaltowski AJ, Shirihai O. Cell culture models of fatty acid overload: Problems and solutions. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1863:143-151. [PMID: 29155055 DOI: 10.1016/j.bbalip.2017.11.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 11/09/2017] [Accepted: 11/14/2017] [Indexed: 12/17/2022]
Abstract
High plasma levels of fatty acids occur in a variety of metabolic diseases. Cellular effects of fatty acid overload resulting in negative cellular responses (lipotoxicity) are often studied in vitro, in an attempt to understand mechanisms involved in these diseases. Fatty acids are poorly soluble, and thus usually studied when complexed to albumins such as bovine serum albumin (BSA). The conjugation of fatty acids to albumin requires care pertaining to preparation of the solutions, effective free fatty acid concentrations, use of different fatty acid species, types of BSA, appropriate controls and ensuring cellular fatty acid uptake. This review discusses lipotoxicity models, the potential problems encountered when using these cellular models, as well as practical solutions for difficulties encountered.
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Affiliation(s)
- Nour Alsabeeh
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA; Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA; Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait
| | - Bruno Chausse
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil
| | - Pamela A Kakimoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil.
| | - Orian Shirihai
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
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Amigo I, Menezes‐Filho SL, Luévano‐Martínez LA, Chausse B, Kowaltowski AJ. Caloric restriction increases brain mitochondrial calcium retention capacity and protects against excitotoxicity. Aging Cell 2017; 16:73-81. [PMID: 27619151 PMCID: PMC5242290 DOI: 10.1111/acel.12527] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2016] [Indexed: 01/09/2023] Open
Abstract
Caloric restriction (CR) protects against many cerebral pathological conditions that are associated with excitotoxic damage and calcium overload, although the mechanisms are still poorly understood. Here we show that CR strongly protects against excitotoxic insults in vitro and in vivo in a manner associated with significant changes in mitochondrial function. CR increases electron transport chain activity, enhances antioxidant defenses, and favors mitochondrial calcium retention capacity in the brain. These changes are accompanied by a decrease in cyclophilin D activity and acetylation and an increase in Sirt3 expression. This suggests that Sirt3-mediated deacetylation and inhibition of cyclophilin D in CR promote the inhibition of mitochondrial permeability transition, resulting in enhanced mitochondrial calcium retention. Altogether, our results indicate that enhanced mitochondrial calcium retention capacity underlies the beneficial effects of CR against excitotoxic conditions. This protection may explain the many beneficial effects of CR in the aging brain.
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Affiliation(s)
- Ignacio Amigo
- Departamento de BioquímicaInstituto de QuímicaUniversidade de São PauloSão PauloBrazil
| | | | | | - Bruno Chausse
- Departamento de BioquímicaInstituto de QuímicaUniversidade de São PauloSão PauloBrazil
| | - Alicia J. Kowaltowski
- Departamento de BioquímicaInstituto de QuímicaUniversidade de São PauloSão PauloBrazil
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Victorino VJ, Barroso WA, Assunção AKM, Cury V, Jeremias IC, Petroni R, Chausse B, Ariga SK, Herrera ACSA, Panis C, Lima TM, Souza HP. PGC-1β regulates HER2-overexpressing breast cancer cells proliferation by metabolic and redox pathways. Tumour Biol 2016; 37:6035-44. [PMID: 26602383 DOI: 10.1007/s13277-015-4449-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/17/2015] [Indexed: 10/22/2022] Open
Abstract
Breast cancer is a prevalent neoplastic disease among women worldwide which treatments still present several side effects and resistance. Considering that cancer cells present derangements in their energetic homeostasis, and that peroxisome proliferator-activated receptor- gamma coactivator 1 (PGC-1) is crucial for cellular metabolism and redox signaling, the main objective of this study was to investigate whether there is a relationship between PGC-1 expression, the proliferation of breast cancer cells and the mechanisms involved. We initially assessed PGC-1β expression in complementary DNA (cDNA) from breast tumor of patients bearing luminal A, luminal B, and HER2-overexpressed and triple negative tumors. Our data showed that PGC-1β expression is increased in patients bearing HER2-overexpressing tumors as compared to others subtypes. Using quantitative PCR and immunoblotting, we showed that breast cancer cells with HER2-amplification (SKBR-3) have greater expression of PGC-1β as compared to a non-tumorous breast cell (MCF-10A) and higher proliferation rate. PGC-1β expression was knocked down with short interfering RNA in HER2-overexpressing cells, and cells decreased proliferation. In these PGC-1β-inhibited cells, we found increased citrate synthase activity and no marked changes in mitochondrial respiration. Glycolytic pathway was decreased, characterized by lower intracellular lactate levels. In addition, after PGC-1β knockdown, SKBR-3 cells showed increased reactive oxygen species production, no changes in antioxidant activity, and decreased expression of ERRα, a modulator of metabolism. In conclusion, we show an association of HER2-overexpression and PGC-1β. PGC-1β knockdown impairs HER2-overexpressing cells proliferation acting on ERRα signaling, metabolism, and redox balance.
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Affiliation(s)
- Vanessa Jacob Victorino
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil.
| | - W A Barroso
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - A K M Assunção
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - V Cury
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - I C Jeremias
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - R Petroni
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - B Chausse
- Instituto de Química, Universidade de São Paulo (IQ-USP), São Paulo, Brazil
| | - S K Ariga
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - A C S A Herrera
- Faculdade de Medicina, Pontifícia Universidade Católica, PUC, Campus Londrina, Paraná, Brazil
| | - C Panis
- Laboratório de Mediadores Inflamatórios, Universidade Estadual do Oeste do Paraná (UNIOESTE), Campus Francisco Beltrão, Paraná, Brazil
| | - T M Lima
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - H P Souza
- Laboratório de Investigação Médica - LIM 51, Faculdade de Medicina, Universidade de São Paulo (FMUSP), São Paulo, Brazil
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12
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Cerqueira FM, Chausse B, Baranovski BM, Liesa M, Lewis EC, Shirihai OS, Kowaltowski AJ. Diluted serum from calorie-restricted animals promotes mitochondrial β-cell adaptations and protect against glucolipotoxicity. FEBS J 2016; 283:822-33. [PMID: 26732506 DOI: 10.1111/febs.13632] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 11/04/2015] [Accepted: 12/16/2015] [Indexed: 12/20/2022]
Abstract
β-cells quickly adjust insulin secretion to oscillations in nutrients carried by the blood, acting as fuel sensors. However, most studies of β-cell responses to nutrients do not discriminate between fuel levels and signaling components present in the circulation. Here we studied the effect of serum from calorie-restricted rats versus serum from rats fed ad libitum, diluted tenfold in the medium, which did not contribute significantly to the pool of nutrients, on β-cell mitochondrial function and dynamics under regular and high-nutrient culture conditions. Insulin secreting beta-cell derived line (INS1) cells incubated with serum from calorie-restricted rats (CR serum) showed higher levels of peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) and active nitric oxide synthase. The expression of mitofusin-2 (Mfn-2) and optic atrophy 1 (OPA-1), proteins involved in mitochondrial fusion, was increased, while the levels of the mitochondrial fission mediator dynamin related protein 1 (DRP-1) were reduced. Consistent with changes in mitochondrial dynamics protein levels, CR serum treatment increased mitochondrial fusion rates, as well as their length and connectivity. These changes in mitochondrial morphology were associated with prolonged glucose-stimulated insulin secretion and mitochondrial respiration. When combining CR serum and high levels of glucose and palmitate (20 and 0.4 mm, respectively), an in vitro model of type II diabetes, we observed that signaling promoted by CR serum was enough to overcome glucolipotoxicity, as indicated by CR-mediated prevention of mitochondrial fusion arrest and reduced respiratory function in INS1 cells under glucolipotoxicity. Overall, our results provide evidence that non-nutrient factors in serum have a major impact on β-cell mitochondrial adaptations to changes in metabolism.
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Affiliation(s)
- Fernanda M Cerqueira
- Department of Medicine, Boston University School of Medicine, MA, USA.,Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel.,Departamento de Bioquímica, Universidade de São Paulo, Brazil
| | - Bruno Chausse
- Departamento de Bioquímica, Universidade de São Paulo, Brazil
| | - Boris M Baranovski
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
| | - Marc Liesa
- Department of Medicine, Boston University School of Medicine, MA, USA.,UCLA Section of Endocrinology, Department of Medicine, David Geffen School of Medicine, UCLA, CA, USA
| | - Eli C Lewis
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
| | - Orian S Shirihai
- Department of Medicine, Boston University School of Medicine, MA, USA.,Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel.,UCLA Section of Endocrinology, Department of Medicine, David Geffen School of Medicine, UCLA, CA, USA
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13
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Affiliation(s)
- Maria Fernanda Forni
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Bruno Chausse
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Julia Peloggia
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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14
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Chausse B, Solon C, Caldeira da Silva CC, Masselli Dos Reis IG, Manchado-Gobatto FB, Gobatto CA, Velloso LA, Kowaltowski AJ. Intermittent fasting induces hypothalamic modifications resulting in low feeding efficiency, low body mass and overeating. Endocrinology 2014; 155:2456-66. [PMID: 24797627 DOI: 10.1210/en.2013-2057] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intermittent fasting (IF) is an often-used intervention to decrease body mass. In male Sprague-Dawley rats, 24 hour cycles of IF result in light caloric restriction, reduced body mass gain, and significant decreases in the efficiency of energy conversion. Here, we study the metabolic effects of IF in order to uncover mechanisms involved in this lower energy conversion efficiency. After 3 weeks, IF animals displayed overeating during fed periods and lower body mass, accompanied by alterations in energy-related tissue mass. The lower efficiency of energy use was not due to uncoupling of muscle mitochondria. Enhanced lipid oxidation was observed during fasting days, whereas fed days were accompanied by higher metabolic rates. Furthermore, an increased expression of orexigenic neurotransmitters AGRP and NPY in the hypothalamus of IF animals was found, even on feeding days, which could explain the overeating pattern. Together, these effects provide a mechanistic explanation for the lower efficiency of energy conversion observed. Overall, we find that IF promotes changes in hypothalamic function that explain differences in body mass and caloric intake.
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Affiliation(s)
- Bruno Chausse
- Departamento de Bioquímica (B.C., C.C.C., A.J.K.), Instituto de Química, Universidade de São Paulo, 05508-000 Brazil; Faculdade de Ciências Médicas (C.S., L.A.V.), Universidade Estadual de Campinas, 13083-970 Brazil; Faculdade de Ciências Aplicadas (I.G.M., F.B.M-G., C.A.G.), Universidade Estadual de Campinas, 13084-350 Brazil
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15
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Cardoso AR, Chausse B, da Cunha FM, Luévano-Martínez LA, Marazzi TBM, Pessoa PS, Queliconi BB, Kowaltowski AJ. Mitochondrial compartmentalization of redox processes. Free Radic Biol Med 2012; 52:2201-8. [PMID: 22564526 DOI: 10.1016/j.freeradbiomed.2012.03.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/05/2012] [Accepted: 03/06/2012] [Indexed: 12/25/2022]
Abstract
Knowledge of location and intracellular subcompartmentalization is essential for the understanding of redox processes, because oxidants, owing to their reactive nature, must be generated close to the molecules modified in both signaling and damaging processes. Here we discuss known redox characteristics of various mitochondrial microenvironments. Points covered are the locations of mitochondrial oxidant generation, characteristics of antioxidant systems in various mitochondrial compartments, and diffusion characteristics of oxidants in mitochondria. We also review techniques used to measure redox state in mitochondrial subcompartments, antioxidants targeted to mitochondrial subcompartments, and methodological concerns that must be addressed when using these tools.
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16
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Cerqueira FM, da Cunha FM, Caldeira da Silva CC, Chausse B, Romano RL, Garcia CCM, Colepicolo P, Medeiros MHG, Kowaltowski AJ. Long-term intermittent feeding, but not caloric restriction, leads to redox imbalance, insulin receptor nitration, and glucose intolerance. Free Radic Biol Med 2011; 51:1454-60. [PMID: 21816219 DOI: 10.1016/j.freeradbiomed.2011.07.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 07/08/2011] [Indexed: 12/13/2022]
Abstract
Calorie restriction is a dietary intervention known to improve redox state, glucose tolerance, and animal life span. Other interventions have been adopted as study models for caloric restriction, including nonsupplemented food restriction and intermittent, every-other-day feedings. We compared the short- and long-term effects of these interventions to ad libitum protocols and found that, although all restricted diets decrease body weight, intermittent feeding did not decrease intra-abdominal adiposity. Short-term calorie restriction and intermittent feeding presented similar results relative to glucose tolerance. Surprisingly, long-term intermittent feeding promoted glucose intolerance, without a loss in insulin receptor phosphorylation. Intermittent feeding substantially increased insulin receptor nitration in both intra-abdominal adipose tissue and muscle, a modification associated with receptor inactivation. All restricted diets enhanced nitric oxide synthase levels in the insulin-responsive adipose tissue and skeletal muscle. However, whereas calorie restriction improved tissue redox state, food restriction and intermittent feedings did not. In fact, long-term intermittent feeding resulted in largely enhanced tissue release of oxidants. Overall, our results show that restricted diets are significantly different in their effects on glucose tolerance and redox state when adopted long-term. Furthermore, we show that intermittent feeding can lead to oxidative insulin receptor inactivation and glucose intolerance.
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Affiliation(s)
- Fernanda M Cerqueira
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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