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Guzmán-Ruíz MA, Guerrero Vargas NN, Ramírez-Carreto RJ, González-Orozco JC, Torres-Hernández BA, Valle-Rodríguez M, Guevara-Guzmán R, Chavarría A. Microglia in physiological conditions and the importance of understanding their homeostatic functions in the arcuate nucleus. Front Immunol 2024; 15:1392077. [PMID: 39295865 PMCID: PMC11408222 DOI: 10.3389/fimmu.2024.1392077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 08/20/2024] [Indexed: 09/21/2024] Open
Abstract
Microglia are highly dynamic cells that have been mainly studied under pathological conditions. The present review discusses the possible implication of microglia as modulators of neuronal electrical responses in physiological conditions and hypothesizes how these cells might modulate hypothalamic circuits in health and during obesity. Microglial cells studied under physiological conditions are highly diverse, depending on the developmental stage and brain region. The evidence also suggests that neuronal electrical activity modulates microglial motility to control neuronal excitability. Additionally, we show that the expression of genes associated with neuron-microglia interaction is down-regulated in obese mice compared to control-fed mice, suggesting an alteration in the contact-dependent mechanisms that sustain hypothalamic arcuate-median eminence neuronal function. We also discuss the possible implication of microglial-derived signals for the excitability of hypothalamic neurons during homeostasis and obesity. This review emphasizes the importance of studying the physiological interplay between microglia and neurons to maintain proper neuronal circuit function. It aims to elucidate how disruptions in the normal activities of microglia can adversely affect neuronal health.
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Affiliation(s)
- Mara A Guzmán-Ruíz
- Programa de Becas Post-doctorales, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Natalí N Guerrero Vargas
- Departamento de Anatomía, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ricardo Jair Ramírez-Carreto
- Unidad de Medicina Experimental "Ruy Pérez Tamayo", Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | | | - Michelle Valle-Rodríguez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Rosalinda Guevara-Guzmán
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Anahí Chavarría
- Unidad de Medicina Experimental "Ruy Pérez Tamayo", Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Todosenko N, Yurova K, Vulf M, Khaziakhmatova O, Litvinova L. Prohibitions in the meta-inflammatory response: a review. Front Mol Biosci 2024; 11:1322687. [PMID: 38813101 PMCID: PMC11133639 DOI: 10.3389/fmolb.2024.1322687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 05/01/2024] [Indexed: 05/31/2024] Open
Abstract
Prohibitins are the central regulatory element of cellular homeostasis, especially by modulating the response at different levels: Nucleus, mitochondria and membranes. Their localization and interaction with various proteins, homons, transcription and nuclear factors, and mtDNA indicate the globality and complexity of their pleiotropic properties, which remain to be investigated. A more detailed deciphering of cellular metabolism in relation to prohibitins under normal conditions and in various metabolic diseases will allow us to understand the precise role of prohibitins in the signaling cascades of PI3K/Akt, Raf/MAP/ERK, STAT3, p53, and others and to fathom their mutual influence. A valuable research perspective is to investigate the role of prohibitins in the molecular and cellular interactions between the two major players in the pathogenesis of obesity-adipocytes and macrophages - that form the basis of the meta-inflammatory response. Investigating the subtle intercellular communication and molecular cascades triggered in these cells will allow us to propose new therapeutic strategies to eliminate persistent inflammation, taking into account novel molecular genetic approaches to activate/inactivate prohibitins.
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Affiliation(s)
- Natalia Todosenko
- Center for Immunology and Cellular Biotechnology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
| | - Kristina Yurova
- Center for Immunology and Cellular Biotechnology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
| | - Maria Vulf
- Center for Immunology and Cellular Biotechnology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
| | - Olga Khaziakhmatova
- Center for Immunology and Cellular Biotechnology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
| | - Larisa Litvinova
- Center for Immunology and Cellular Biotechnology, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
- Laboratory of Cellular and Microfluidic Technologies, Siberian State Medical University, Tomsk, Russia
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Chen L, Zhao S, Wang Y, Niu X, Zhang B, Li X, Peng D. Genetic Insights into Obesity and Brain: Combine Mendelian Randomization Study and Gene Expression Analysis. Brain Sci 2023; 13:892. [PMID: 37371369 PMCID: PMC10295948 DOI: 10.3390/brainsci13060892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
As a major public-health concern, obesity is imposing an increasing social burden around the world. The link between obesity and brain-health problems has been reported, but controversy remains. To investigate the relationship among obesity, brain-structure changes and diseases, a two-stage analysis was performed. At first, we used the Mendelian-randomization (MR) approach to identify the causal relationship between obesity and cerebral structure. Obesity-related data were retrieved from the Genetic Investigation of ANthropometric Traits (GIANT) consortium and the UK Biobank, whereas the cortical morphological data were from the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) consortium. Further, we extracted region-specific expressed genes according to the Allen Human Brian Atlas (AHBA) and carried out a series of bioinformatics analyses to find the potential mechanism of obesity and diseases. In the univariable MR, a higher body mass index (BMI) or larger visceral adipose tissue (VAT) was associated with a smaller global cortical thickness (pBMI = 0.006, pVAT = 1.34 × 10-4). Regional associations were found between obesity and specific gyrus regions, mainly in the fusiform gyrus and inferior parietal gyrus. Multivariable MR results showed that a greater body fat percentage was linked to a smaller fusiform-gyrus thickness (p = 0.029) and precuneus surface area (p = 0.035). As for the gene analysis, region-related genes were enriched to several neurobiological processes, such as compound transport, neuropeptide-signaling pathway, and neuroactive ligand-receptor interaction. These genes contained a strong relationship with some neuropsychiatric diseases, such as Alzheimer's disease, epilepsy, and other disorders. Our results reveal a causal relationship between obesity and brain abnormalities and suggest a pathway from obesity to brain-structure abnormalities to neuropsychiatric diseases.
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Affiliation(s)
- Leian Chen
- Department of Neurology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100029, China
| | - Shaokun Zhao
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
| | - Yuye Wang
- Department of Neurology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100029, China
| | - Xiaoqian Niu
- Department of Neurology, Peking University China-Japan Friendship School of Clinical Medicine, Beijing 100029, China
| | - Bin Zhang
- Department of Neurology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100029, China
| | - Xin Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
| | - Dantao Peng
- Department of Neurology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100029, China
- Department of Neurology, Peking University China-Japan Friendship School of Clinical Medicine, Beijing 100029, China
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Gómez‐Apo E, Silva‐Pereyra J, Soto‐Abraham V, Mondragón‐Maya A, Sanchez‐Lopez J. Immunohistochemical analysis of caspase expression in the brains of individuals with obesity or overweight. Obes Sci Pract 2022; 9:137-144. [PMID: 37034564 PMCID: PMC10073824 DOI: 10.1002/osp4.632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 07/03/2022] [Accepted: 07/26/2022] [Indexed: 11/10/2022] Open
Abstract
Mechanisms underlying the negative effects of obesity on the brain are still unknown. Obesity is associated with oxidative stress in the brain and neuroinflammation that promotes neurodegenerative diseases. Chronic low-grade neuroinflammation in obesity could be associated with lower volumes of gray matter and lower neuronal density. If neuroinflammation mediated by the expression of cytokines and chemokines leads to apoptosis, this can be assessed by examining caspase expression. The aim of this study was to compare the expression of caspases in the 16 brains of donors with obesity/overweight (n = 8; Body Mass Index [BMI] = 31.6 ± 4.35 kg/m2; 2 females; Age = 52.9 ± 4.76 years) and normal weight (n = 8; BMI = 21.8 ± 1.5 kg/m2; 3 females; Age = 37.8 ± 19.2 years). Sixteen human brain samples were processed. Serial paraffin sections were examined by anti-caspase immunochemistry (caspase-3, caspase-4, caspase-6, caspase-1, caspase-8, and caspase-9 antibodies). Postmortem samples of cerebral cortex tissue were captured as photomicrographs and the images obtained were analyzed using ImageJ software to obtain the percentage of positive caspase expression. Nonparametric Mann-Whitney U tests were performed to compare caspase expression between samples from donors with obesity/overweight and normal weight. Taking into consideration the immunohistochemistry results, the Search Tool for the Retrieval of Interacting Genes was used to model molecular interactions. Results showed that brain samples from individuals with obesity/overweight exhibited significantly greater values of positive expression for Caspase-1 (U = 16.5, p = 0.05, Cohen d = 0.89) and -8 (U = 15, p = 0.03, Cohen d = 0.99) than those from donors with normal weight. This study contributes to the knowledge about the inflammatory effects of obesity/overweight on brain, suggesting the activation of the alternative inflammasome pathway in which interact caspase-1 and -8.
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Affiliation(s)
- Erick Gómez‐Apo
- Servicio de Anatomía Patológica Hospital General de México “Dr. Eduardo Liceaga” Ciudad de México México
- Programa de Maestría y Doctorado en Ciencias Médicas y Odontológicas y de la Salud Universidad Nacional Autónoma de México Ciudad de México México
| | - Juan Silva‐Pereyra
- Facultad de Estudios Superiores Iztacala Universidad Nacional Autónoma de México Tlalnepantla Estado de México México
| | - Virgilia Soto‐Abraham
- Servicio de Anatomía Patológica Hospital General de México “Dr. Eduardo Liceaga” Ciudad de México México
| | - Alejandra Mondragón‐Maya
- Facultad de Estudios Superiores Iztacala Universidad Nacional Autónoma de México Tlalnepantla Estado de México México
| | - Javier Sanchez‐Lopez
- Escuela Nacional de Estudios Superiores Unidad Juriquilla Universidad Nacional Autónoma de México Querétaro Querétaro México
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Contribution of specific ceramides to obesity-associated metabolic diseases. Cell Mol Life Sci 2022; 79:395. [PMID: 35789435 PMCID: PMC9252958 DOI: 10.1007/s00018-022-04401-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/20/2022] [Accepted: 05/26/2022] [Indexed: 12/04/2022]
Abstract
Ceramides are a heterogeneous group of bioactive membrane sphingolipids that play specialized regulatory roles in cellular metabolism depending on their characteristic fatty acyl chain lengths and subcellular distribution. As obesity progresses, certain ceramide molecular species accumulate in metabolic tissues and cause cell-type-specific lipotoxic reactions that disrupt metabolic homeostasis and lead to the development of cardiometabolic diseases. Several mechanisms for ceramide action have been inferred from studies in vitro, but only recently have we begun to better understand the acyl chain length specificity of ceramide-mediated signaling in the context of physiology and disease in vivo. New discoveries show that specific ceramides affect various metabolic pathways and that global or tissue-specific reduction in selected ceramide pools in obese rodents is sufficient to improve metabolic health. Here, we review the tissue-specific regulation and functions of ceramides in obesity, thus highlighting the emerging concept of selectively inhibiting production or action of ceramides with specific acyl chain lengths as novel therapeutic strategies to ameliorate obesity-associated diseases.
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Salgado M, García-Robles MÁ, Sáez JC. Purinergic signaling in tanycytes and its contribution to nutritional sensing. Purinergic Signal 2021; 17:607-618. [PMID: 34018139 DOI: 10.1007/s11302-021-09791-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 04/19/2021] [Indexed: 10/21/2022] Open
Abstract
Tanycytes are hypothalamic radial glial-like cells with an important role in the regulation of neuroendocrine axes and energy homeostasis. These cells have been implicated in glucose, amino acids, and fatty acid sensing in the hypothalamus of rodents, where they are strategically positioned. While their cell bodies contact the cerebrospinal fluid, their extensive processes contact neurons of the arcuate and ventromedial nuclei, protagonists in the regulation of food intake. A growing body of evidence has shown that purinergic signaling plays a relevant role in this homeostatic role of tanycytes, likely regulating the release of gliotransmitters that will modify the activity of satiety-controlling hypothalamic neurons. Connexin hemichannels have proven to be particularly relevant in these mechanisms since they are responsible for the release of ATP from tanycytes in response to nutritional signals. On the other hand, either ionotropic or metabotropic ATP receptors are involved in the generation of intracellular Ca2+ waves in response to hypothalamic nutrients, which can spread between glial cells and towards neighboring neurons. This review will summarize recent evidence that supports a nutrient sensor role for tanycytes, highlighting the participation of purinergic signaling in this process.
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Affiliation(s)
- Magdiel Salgado
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - María Á García-Robles
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
| | - Juan C Sáez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
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Reginato A, Veras ACC, Baqueiro MDN, Panzarin C, Siqueira BP, Milanski M, Lisboa PC, Torsoni AS. The Role of Fatty Acids in Ceramide Pathways and Their Influence on Hypothalamic Regulation of Energy Balance: A Systematic Review. Int J Mol Sci 2021; 22:5357. [PMID: 34069652 PMCID: PMC8160791 DOI: 10.3390/ijms22105357] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/30/2021] [Accepted: 05/06/2021] [Indexed: 12/09/2022] Open
Abstract
Obesity is a global health issue for which no major effective treatments have been well established. High-fat diet consumption is closely related to the development of obesity because it negatively modulates the hypothalamic control of food intake due to metaflammation and lipotoxicity. The use of animal models, such as rodents, in conjunction with in vitro models of hypothalamic cells, can enhance the understanding of hypothalamic functions related to the control of energy balance, thereby providing knowledge about the impact of diet on the hypothalamus, in addition to targets for the development of new drugs that can be used in humans to decrease body weight. Recently, sphingolipids were described as having a lipotoxic effect in peripheral tissues and the central nervous system. Specifically, lipid overload, mainly from long-chain saturated fatty acids, such as palmitate, leads to excessive ceramide levels that can be sensed by the hypothalamus, triggering the dysregulation of energy balance control. However, no systematic review has been undertaken regarding studies of sphingolipids, particularly ceramide and sphingosine-1-phosphate (S1P), the hypothalamus, and obesity. This review confirms that ceramides are associated with hypothalamic dysfunction in response to metaflammation, endoplasmic reticulum (ER) stress, and lipotoxicity, leading to insulin/leptin resistance. However, in contrast to ceramide, S1P appears to be a central satiety factor in the hypothalamus. Thus, our work describes current evidence related to sphingolipids and their role in hypothalamic energy balance control. Hypothetically, the manipulation of sphingolipid levels could be useful in enabling clinicians to treat obesity, particularly by decreasing ceramide levels and the inflammation/endoplasmic reticulum stress induced in response to overfeeding with saturated fatty acids.
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Affiliation(s)
- Andressa Reginato
- Biology Institute, State University of Rio de Janeiro, UERJ, Rio de Janeiro 20551-030, Brazil;
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
| | - Alana Carolina Costa Veras
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
| | - Mayara da Nóbrega Baqueiro
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
| | - Carolina Panzarin
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
| | - Beatriz Piatezzi Siqueira
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
| | - Marciane Milanski
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
| | | | - Adriana Souza Torsoni
- Faculty of Applied Science, University of Campinas, UNICAMP, Campinas 13484-350, Brazil; (A.C.C.V.); (M.d.N.B.); (C.P.); (B.P.S.); (M.M.)
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas 13083-864, Brazil
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