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Stark R. The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism. J Neuroendocrinol 2024; 36:e13382. [PMID: 38468186 DOI: 10.1111/jne.13382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/13/2024]
Abstract
Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.
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Affiliation(s)
- Romana Stark
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
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2
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Xie Y, Cai L, Ding M, Shan K, Zhao D, Zhou G, Li C. Plant-based meat analogues enhance the gastrointestinal motility function and appetite of mice by specific volatile compounds and peptides. Food Res Int 2023; 174:113551. [PMID: 37986430 DOI: 10.1016/j.foodres.2023.113551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 11/22/2023]
Abstract
Eating behavior is critical for maintaining energy homeostasis. Previous studies have found that plant-based meat analogues increased diet intake in mice compared with animal meat under a free feeding mode, however the reasons were unclear. To explore the underlying mechanisms of plant-based meat analogues increasing diet intake, mice were fed animal or plant-based pork and beef analogue diets, respectively. Biochemical and histological analyses were performed to evaluate appetite-regulating hormones and gastrointestinal motility function. Peptiomics and GC-IMS were applied to identify key substances. We found that the intake of plant-based meat analogues significantly enhanced the gastrointestinal motility function of mice. The long-term intake (68 days) of plant-based meat analogues significantly increased the muscle layer thickness of the duodenum and jejunum of mice; the activity of gastrointestinal cells of Cajal were also promoted by upregulating the expression of c-kit related signals as compared to animal meat; plant-based meat analogues intake markedly enhanced the signal intensity of the intestinal neurotransmitter 5-hydroxytryptamine (5-HT) by upregulating the expression of 5-HT synthase and receptors but downregulating its transporter and catabolic enzyme in the intestine. Moreover, plant-based meat analogues intake significantly increased levels of appetite-stimulating factors in the peripheral or hypothalamus but reduced levels of appetite-suppressing factors compared with animal meat. Specific volatile compounds were significantly associated with appetite regulating factors. Among them, 7 substances such as linalool have a potential promoting effect on food intake. Besides, different digestive peptides in gastrointestinal tract may affect eating behavior mainly through the neuroactive ligand-receptor interaction pathway, exerting hormone-like effects or influencing endocrine cell secretion. These findings preliminarily clarified the mechanism of plant-based meat analogues promoting diet intake and provided a theoretical basis for a reasonable diet.
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Affiliation(s)
- Yunting Xie
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Linlin Cai
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Mengzhen Ding
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Kai Shan
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Di Zhao
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Guanghong Zhou
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunbao Li
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, MOST, Key Laboratory of Meat Processing, MARA, Jiangsu Innovative Center of Meat Production, Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
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3
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Melis M, Tomassini Barbarossa I, Crnjar R, Sollai G. Olfactory Sensitivity Is Associated with Body Mass Index and Polymorphism in the Voltage-Gated Potassium Channels Kv1.3. Nutrients 2022; 14:nu14234986. [PMID: 36501016 PMCID: PMC9736683 DOI: 10.3390/nu14234986] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
Smell strongly contributes to food choice and its hedonistic evaluation. A reduction or loss of smell has been related to malnutrition problems, resulting in excessive weight loss or gain. Voltage-gated potassium channels Kv1.3 are widely expressed in the olfactory bulb, and contribute mainly to the value of the resting membrane potential and to the frequency of action potentials. Mutations in the Kv1.3 gene are associated with alterations in glycemic homeostasis and olfactory sensitivity. We evaluated the olfactory performance in 102 healthy subjects and its association with BMI and polymorphism in the human Kv1.3 gene. Olfactory performance, based on the olfactory threshold, discrimination and identification scores and their summed score (TDI), was measured using the “Sniffin’ Sticks” test. Subjects were genotyped for the rs2821557 polymorphism of the Kv1.3 gene, whose major allele T was associated with a super-smeller phenotype, lower plasma glucose levels and resistance to diet-induced obesity as compared with the minor allele C. Based on the Kv1.3 genotype, the TDI and I olfactory scores obtained by the subjects were the following: TT > TC > CC. Subjects who were TT homozygous or heterozygous exhibited lower BMIs and reached higher olfactory scores than those with the CC genotype. The results were sex-dependent: heterozygous females performed better than heterozygous males. These findings show an inverse relationship between olfactory function and BMI, and a significant effect of the Kv1.3 genotypes on the olfactory functions and on the BMIs of the subjects. Finally, they suggest that the sex-related differences in the olfactory function can be partially ascribed to the Kv1.3 gene’s polymorphism.
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Odell SR, Clark D, Zito N, Jain R, Gong H, Warnock K, Carrion-Lopez R, Maixner C, Prieto-Godino L, Mathew D. Internal state affects local neuron function in an early sensory processing center to shape olfactory behavior in Drosophila larvae. Sci Rep 2022; 12:15767. [PMID: 36131078 PMCID: PMC9492728 DOI: 10.1038/s41598-022-20147-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/09/2022] [Indexed: 02/03/2023] Open
Abstract
Crawling insects, when starved, tend to have fewer head wavings and travel in straighter tracks in search of food. We used the Drosophila melanogaster larva to investigate whether this flexibility in the insect's navigation strategy arises during early olfactory processing and, if so, how. We demonstrate a critical role for Keystone-LN, an inhibitory local neuron in the antennal lobe, in implementing head-sweep behavior. Keystone-LN responds to odor stimuli, and its inhibitory output is required for a larva to successfully navigate attractive and aversive odor gradients. We show that insulin signaling in Keystone-LN likely mediates the starvation-dependent changes in head-sweep magnitude, shaping the larva's odor-guided movement. Our findings demonstrate how flexibility in an insect's navigation strategy can arise from context-dependent modulation of inhibitory neurons in an early sensory processing center. They raise new questions about modulating a circuit's inhibitory output to implement changes in a goal-directed movement.
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Affiliation(s)
- Seth R Odell
- Integrative Neuroscience Program, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA
| | - David Clark
- Integrative Neuroscience Program, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA
| | - Nicholas Zito
- Integrative Neuroscience Program, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA
| | - Roshni Jain
- Molecular Biosciences Program, University of Nevada, Reno, NV, 89557, USA
| | - Hui Gong
- The Francis Crick Institute, London, NW1 1AT, UK
| | - Kendall Warnock
- Department of Biology, University of Nevada, Reno, NV, 89557, USA
| | | | - Coral Maixner
- NSF-REU (BioSoRo) Program, University of Nevada, Reno, NV, 89557, USA
| | | | - Dennis Mathew
- Integrative Neuroscience Program, University of Nevada, 1664 N. Virginia St., MS: 0314, Reno, NV, 89557, USA.
- Molecular Biosciences Program, University of Nevada, Reno, NV, 89557, USA.
- Department of Biology, University of Nevada, Reno, NV, 89557, USA.
- NSF-REU (BioSoRo) Program, University of Nevada, Reno, NV, 89557, USA.
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5
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Kolling LJ, Tatti R, Lowry T, Loeven AM, Fadool JM, Fadool DA. Modulating the Excitability of Olfactory Output Neurons Affects Whole-Body Metabolism. J Neurosci 2022; 42:5966-5990. [PMID: 35710623 PMCID: PMC9337614 DOI: 10.1523/jneurosci.0190-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 01/29/2023] Open
Abstract
Metabolic state can alter olfactory sensitivity, but it is unknown whether the activity of the olfactory bulb (OB) may fine tune metabolic homeostasis. Our objective was to use CRISPR gene editing in male and female mice to enhance the excitability of mitral/tufted projection neurons (M/TCs) of the OB to test for improved metabolic health. Ex vivo slice recordings of MCs in CRISPR mice confirmed increased excitability due the targeted loss of Kv1.3 channels, which resulted in a less negative resting membrane potential (RMP), enhanced action potential (AP) firing, and insensitivity to the selective channel blocker margatoxin (MgTx). CRISPR mice exhibited enhanced odor discrimination using a habituation/dishabituation paradigm. CRISPR mice were challenged for 25 weeks with a moderately high-fat (MHF) diet, and compared with littermate controls, male mice were resistance to diet-induced obesity (DIO). Female mice did not exhibit DIO. CRISPR male mice gained less body weight, accumulated less white adipose tissue, cleared a glucose challenge more quickly, and had less serum leptin and liver triglycerides. CRISPR male mice consumed equivalent calories as control littermates, and had unaltered energy expenditure (EE) and locomotor activity, but used more fats for metabolic substrate over that of carbohydrates. Counter to CRISPR-engineered mice, by using chemogenetics to decrease M/TC excitability in male mice, activation of inhibitory designer receptors exclusively activated by designer drugs (DREADDs) caused a decrease in odor discrimination, and resulted in a metabolic profile that was obesogenic, mice had reduced EE and oxygen consumption (VO2). We conclude that the activity of M/TC projection neurons canonically carries olfactory information and simultaneously can regulate whole-body metabolism.SIGNIFICANCE STATEMENT The olfactory system drives food choice, and olfactory sensitivity is strongly correlated to hunger and fullness. Olfactory function thereby influences nutritional balance and obesity outcomes. Obesity has become a health and financial crisis in America, shortening life expectancy and increasing the severity of associated illnesses. It is expected that 51% of Americans will be obese by the year 2030. Using CRISPR gene editing and chemogenetic approaches, we discovered that changing the excitability of output neurons in the olfactory bulb (OB) affects metabolism and body weight stabilization in mice. Our results suggest that long-term therapeutic targeting of OB activity to higher processing centers may be a future clinical treatment of obesity or type II Diabetes.
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Affiliation(s)
- Louis John Kolling
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida 32306
| | - Roberta Tatti
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306
| | - Troy Lowry
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306
| | - Ashley M Loeven
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306
| | - James M Fadool
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306
- Program in Neuroscience, The Florida State University, Tallahassee, Florida 32306
| | - Debra Ann Fadool
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida 32306
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306
- Program in Neuroscience, The Florida State University, Tallahassee, Florida 32306
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Faour M, Magnan C, Gurden H, Martin C. Olfaction in the context of obesity and diabetes: Insights from animal models to humans. Neuropharmacology 2021; 206:108923. [PMID: 34919903 DOI: 10.1016/j.neuropharm.2021.108923] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 12/07/2021] [Accepted: 12/10/2021] [Indexed: 12/12/2022]
Abstract
The olfactory system is at the crossroad between sensory processing and metabolic sensing. In addition to being the center of detection and identification of food odors, it is a sensor for most of the hormones and nutrients responsible for feeding behavior regulation. The consequences of modifications in body homeostasis, nutrient overload and alteration of this brain network in the pathological condition of food-induced obesity and type 2 diabetes are still not elucidated. The aim of this review was first to use both humans and animal studies to report on the current knowledge of the consequences of obesity and type 2 diabetes on odorant threshold and olfactory perception including identification discrimination and memory. We then discuss how olfactory processing can be modified by an alteration of the metabolic homeostasis of the organism and available elements on pharmacological treatments that regulate olfaction. We focus on data within the olfactory system but also on the interactions between the olfactory system and other brain networks impacted by metabolic diseases.
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Affiliation(s)
- Maya Faour
- Université de Paris, BFA, UMR 8251, CNRS, F-75013, Paris, France
| | | | - Hirac Gurden
- Université de Paris, BFA, UMR 8251, CNRS, F-75013, Paris, France
| | - Claire Martin
- Université de Paris, BFA, UMR 8251, CNRS, F-75013, Paris, France.
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Melis M, Pintus S, Mastinu M, Fantola G, Moroni R, Pepino MY, Tomassini Barbarossa I. Changes of Taste, Smell and Eating Behavior in Patients Undergoing Bariatric Surgery: Associations with PROP Phenotypes and Polymorphisms in the Odorant-Binding Protein OBPIIa and CD36 Receptor Genes. Nutrients 2021; 13:nu13010250. [PMID: 33467165 PMCID: PMC7830302 DOI: 10.3390/nu13010250] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/08/2021] [Accepted: 01/13/2021] [Indexed: 02/08/2023] Open
Abstract
Bariatric surgery is the most effective long-term treatment for severe obesity and related comorbidities. Although patients who underwent bariatric surgery report changes of taste and smell perception, results from sensory studies are discrepant and limited. Here, we assessed taste and smell functions in 51 patients before, one month, and six months after undergoing bariatric surgery. We used taste strip tests to assess gustatory function (including sweetness, saltiness, sourness, umaminess, bitterness and oleic acid, a fatty stimulus), the “Sniffin’ Sticks” test to assess olfactory identification and the 3-Factor Eating Questionnaire to assess eating behavior. We also explored associations between these phenotypes and flavor-related genes. Results showed an overall improvement in taste function (including increased sensitivity to oleic acid and the bitterness of 6-n-propylthiouracil (PROP)) and in olfactory function (which could be related to the increase in PROP and oleic acid sensitivity), an increase in cognitive restraint, and a decrease in disinhibition and hunger after bariatric surgery. These findings indicate that bariatric surgery can have a positive impact on olfactory and gustatory functions and eating behavior (with an important role of genetic factors, such PROP tasting), which in turn might contribute to the success of the intervention.
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Affiliation(s)
- Melania Melis
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (M.M.); (I.T.B.)
- Correspondence: ; Tel.: +39-070-675-4142
| | - Stefano Pintus
- Obesity Surgical Unit ARNAS G. Brotzu, 09121 Cagliari, Italy; (S.P.); (G.F.); (R.M.)
| | - Mariano Mastinu
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (M.M.); (I.T.B.)
| | - Giovanni Fantola
- Obesity Surgical Unit ARNAS G. Brotzu, 09121 Cagliari, Italy; (S.P.); (G.F.); (R.M.)
| | - Roberto Moroni
- Obesity Surgical Unit ARNAS G. Brotzu, 09121 Cagliari, Italy; (S.P.); (G.F.); (R.M.)
| | - Marta Yanina Pepino
- Department of Food Science and Human Nutrition, University of Illinois, Urbana Champaign, Urbana, IL 61801, USA;
| | - Iole Tomassini Barbarossa
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (M.M.); (I.T.B.)
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Schwartz AB, Kapur A, Huang Z, Anangi R, Spear JM, Stagg S, Fardone E, Dekan Z, Rosenberg JT, Grant SC, King GF, Mattoussi H, Fadool DA. Olfactory bulb-targeted quantum dot (QD) bioconjugate and Kv1.3 blocking peptide improve metabolic health in obese male mice. J Neurochem 2020; 157:1876-1896. [PMID: 32978815 DOI: 10.1111/jnc.15200] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 01/10/2023]
Abstract
The olfactory system is a driver of feeding behavior, whereby olfactory acuity is modulated by the metabolic state of the individual. The excitability of the major output neurons of the olfactory bulb (OB) can be modulated through targeting a voltage-dependent potassium channel, Kv1.3, which responds to changes in metabolic factors such as insulin, glucose, and glucagon-like peptide-1. Because gene-targeted deletion or inhibition of Kv1.3 in the periphery has been found to increase energy metabolism and decrease body weight, we hypothesized that inhibition of Kv1.3 selectively in the OB could enhance excitability of the output neurons to evoke changes in energy homeostasis. We thereby employed metal-histidine coordination to self-assemble the Kv1.3 inhibitor margatoxin (MgTx) to fluorescent quantum dots (QDMgTx) as a means to label cells in vivo and test changes in neuronal excitability and metabolism when delivered to the OB. Using patch-clamp electrophysiology to measure Kv1.3 properties in heterologously expressed cells and native mitral cells in OB slices, we found that QDMgTx had a fast rate of inhibition, but with a reduced IC50, and increased action potential firing frequency. QDMgTx was capable of labeling cloned Kv1.3 channels but was not visible when delivered to native Kv1.3 in the OB. Diet-induced obese mice were observed to reduce body weight and clear glucose more quickly following osmotic mini-pump delivery of QDMgTx/MgTx to the OB, and following MgTx delivery, they increased the use of fats as fuels (reduced respiratory exchange ratio). These results suggest that enhanced excitability of bulbar output neurons can drive metabolic responses.
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Affiliation(s)
- Austin B Schwartz
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, FL, USA
| | - Anshika Kapur
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA
| | - Zhenbo Huang
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.,Department of Biological Science, The Florida State University, Tallahassee, FL, USA
| | - Raveendra Anangi
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - John M Spear
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Scott Stagg
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Erminia Fardone
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA
| | - Zolan Dekan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Jens T Rosenberg
- National High Field Magnetic Laboratory, The Florida State University, Tallahassee, FL, USA
| | - Samuel C Grant
- National High Field Magnetic Laboratory, The Florida State University, Tallahassee, FL, USA.,Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, USA
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Hedi Mattoussi
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL, USA
| | - Debra Ann Fadool
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, FL, USA.,Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.,Department of Biological Science, The Florida State University, Tallahassee, FL, USA
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9
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Dynamic changes of blood glucose, serum biochemical parameters and gene expression in response to exogenous insulin in Arbor Acres broilers and Silky fowls. Sci Rep 2020; 10:6697. [PMID: 32317707 PMCID: PMC7174311 DOI: 10.1038/s41598-020-63549-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/26/2020] [Indexed: 11/14/2022] Open
Abstract
Silky chicken is a breed of chickens with black skin and slow growth rate used in Chinese traditional medicine, whereas Arbor Acres broiler is a well-known commercial breed in the poultry industry, it is featured by a large size, rapid-growth rate, high feed-conversion rate and strong adaptability. The difference in their rate of growth may be primarily related to different mechanism for glucose metabolism. Here we compared the insulin sensitivity of the two breeds; we investigated the temporal changes (at 0 min, 120 min and 240 min) of serum insulin and other biochemical parameters and determined the spatio-temporal changes of gene mRNA abundance in response to exogenous insulin (80 μg/kg body weight). The results indicated that: (1) Silky chickens showed stronger blood glucose recovery than broilers in the insulin resistance test. (2) The serum urea level in Silky chickens was twice of broilers; exogenous insulin significantly up-regulated serum uric acid level in Silky fowls in a time-dependent manner and increased serum cholesterol content at 120 min. (3) Two breeds showed distinctly different temporal changed in serum insulin in response to exogenous insulin stimulation. The fasting serum insulin concentration of broilers was three-fold of Silky chickens at the basal state; it decreased significantly after insulin injection and the levels at 120 min and 240 min of broilers were only 23% (P < 0.01) and 14% (P < 0.01) of the basal state, respectively. Whereas the serum insulin content in Silky chickens showed stronger recovery, and the 240 min level was close to the 0 min level. (4) GLUT2, GLUT12, neuropeptide Y and insulin receptor (IR) were predominantly expressed in the liver, pectoralis major, olfactory bulb and pancreas, respectively, where these genes presented stronger insulin sensitivity. In addition, the IR mRNA level was strongly positively with the GLUT12 level. In conclusion, our findings suggested that Silky chickens have a stronger ability to regulate glucose homeostasis than broilers, owing to their higher IR levels in the basal state, stronger serum insulin homeostasis and candidate genes functioning primarily in their predominantly expressed tissue in response to exogenous insulin.
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10
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Oliveira IS, Ferreira IG, Alexandre-Silva GM, Cerni FA, Cremonez CM, Arantes EC, Zottich U, Pucca MB. Scorpion toxins targeting Kv1.3 channels: insights into immunosuppression. J Venom Anim Toxins Incl Trop Dis 2019; 25:e148118. [PMID: 31131004 PMCID: PMC6483409 DOI: 10.1590/1678-9199-jvatitd-1481-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/17/2018] [Indexed: 01/26/2023] Open
Abstract
Scorpion venoms are natural sources of molecules that have, in addition to their
toxic function, potential therapeutic applications. In this source the
neurotoxins can be found especially those that act on potassium channels.
Potassium channels are responsible for maintaining the membrane potential in the
excitable cells, especially the voltage-dependent potassium channels (Kv),
including Kv1.3 channels. These channels (Kv1.3) are expressed by various types
of tissues and cells, being part of several physiological processes. However,
the major studies of Kv1.3 are performed on T cells due its importance on
autoimmune diseases. Scorpion toxins capable of acting on potassium channels
(KTx), mainly on Kv1.3 channels, have gained a prominent role for their possible
ability to control inflammatory autoimmune diseases. Some of these toxins have
already left bench trials and are being evaluated in clinical trials, presenting
great therapeutic potential. Thus, scorpion toxins are important natural
molecules that should not be overlooked in the treatment of autoimmune and other
diseases.
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Affiliation(s)
- Isadora S Oliveira
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Isabela G Ferreira
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Felipe A Cerni
- Ribeirão Preto Medical School, Department of Biochemistry and Immunology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Caroline M Cremonez
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Eliane C Arantes
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Umberto Zottich
- Medical School, Federal University of Roraima, Boa Vista, RR, Brazil
| | - Manuela B Pucca
- Medical School, Federal University of Roraima, Boa Vista, RR, Brazil
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11
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Huang Z, Hoffman CA, Chelette BM, Thiebaud N, Fadool DA. Elevated Anxiety and Impaired Attention in Super-Smeller, Kv1.3 Knockout Mice. Front Behav Neurosci 2018; 12:49. [PMID: 29615878 PMCID: PMC5867313 DOI: 10.3389/fnbeh.2018.00049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/28/2018] [Indexed: 12/27/2022] Open
Abstract
It has long been recognized that olfaction and emotion are linked. While chemosensory research using both human and rodent models have indicated a change in emotion can contribute to olfactory dysfunction, there are few studies addressing the contribution of olfaction to a modulation in emotion. In mice, olfactory deficits have been linked with heightened anxiety levels, suggesting that there could be an inverse relationship between olfaction and anxiety. Furthermore, increased anxiety is often co-morbid with psychiatric conditions such as attention disorders. Our study aimed to investigate the roles of olfaction in modulating anxiety. Voltage-gated potassium ion channel Kv1.3 knockout mice (Kv1.3−/−), which have heightened olfaction, and wild-type (WT) mice were examined for anxiety-like behaviors using marble burying (MB), light-dark box (LDB) and elevated-plus maze (EPM) tests. Because Kv1.3−/− mice have increased locomotor activity, inattentive and hyperactive behaviors were quantified for both genotypes. Kv1.3−/− mice showed increased anxiety levels compared to their WT counterparts and administration of methylphenidate (MPH) via oral gavage alleviated their increased anxiety. Object-based attention testing indicated young and older Kv1.3−/− mice had attention deficits and treatment with MPH also ameliorated this condition. Locomotor testing through use of a metabolic chamber indicated that Kv1.3−/− mice were not significantly hyperactive and MPH treatment failed to modify this activity. Our data suggest that heightened olfaction does not necessarily lead to decreased anxiety levels, and that Kv1.3−/− mice may have behaviors associated with inattentiveness.
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Affiliation(s)
- Zhenbo Huang
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Program in Neuroscience, Florida State University, Tallahassee, FL, United States
| | - Carlie A Hoffman
- Department of Biological Science, Florida State University, Tallahassee, FL, United States
| | - Brandon M Chelette
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Program in Neuroscience, Florida State University, Tallahassee, FL, United States
| | - Nicolas Thiebaud
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Program in Neuroscience, Florida State University, Tallahassee, FL, United States
| | - Debra A Fadool
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Program in Neuroscience, Florida State University, Tallahassee, FL, United States.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
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12
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McIntyre JC, Thiebaud N, McGann JP, Komiyama T, Rothermel M. Neuromodulation in Chemosensory Pathways. Chem Senses 2017; 42:375-379. [PMID: 28379355 DOI: 10.1093/chemse/bjx014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Interactions with the environment depend not only on sensory perception of external stimuli but also on processes of neuromodulation regulated by the internal state of an organism. These processes allow regulation of stimulus detection to match the demands of an organism influenced by its general brain state (satiety, wakefulness/sleep state, attentiveness, arousal, learning etc.). The sense of smell is initiated by sensory neurons located in the nasal cavity that recognize environmental odorants and project axons into the olfactory bulb (OB), where they form synapses with several types of neurons. Modulations of early synaptic circuits are particularly important since these can affect all subsequent processing steps. While the precise mechanisms have not been fully elucidated, work from many labs has demonstrated that the activity of neurons in the OB and cortex can be modulated by different factors inducing specific changes to olfactory information processing. The symposium "Neuromodulation in Chemosensory Pathways" at the International Symposium on Olfaction and Taste (ISOT 2016) highlighted some of the most recent advances in state-dependent network modulations of the mouse olfactory system including modulation mediated by specific neurotransmitters and neuroendocrine molecules, involving pharmacological, electrophysiological, learning, and behavioral approaches.
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Affiliation(s)
- Jeremy C McIntyre
- Department of Neuroscience and.,Center for Smell and Taste, University of Florida, PO Box 100244, Gainesville, FL 32610, USA
| | - Nicolas Thiebaud
- Department of Biological Science and.,Program in Neuroscience, The Florida State University, Tallahassee, FL 32306, USA
| | - John P McGann
- Behavioral and Systems Neuroscience, Psychology Department, Rutgers University, New Brunswick, NJ, USA
| | - Takaki Komiyama
- Neurobiology Section and Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA and
| | - Markus Rothermel
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, Aachen 52074, Germany
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13
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Julliard AK, Al Koborssy D, Fadool DA, Palouzier-Paulignan B. Nutrient Sensing: Another Chemosensitivity of the Olfactory System. Front Physiol 2017; 8:468. [PMID: 28747887 PMCID: PMC5506222 DOI: 10.3389/fphys.2017.00468] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/19/2017] [Indexed: 12/31/2022] Open
Abstract
Olfaction is a major sensory modality involved in real time perception of the chemical composition of the external environment. Olfaction favors anticipation and rapid adaptation of behavioral responses necessary for animal survival. Furthermore, recent studies have demonstrated that there is a direct action of metabolic peptides on the olfactory network. Orexigenic peptides such as ghrelin and orexin increase olfactory sensitivity, which in turn, is decreased by anorexigenic hormones such as insulin and leptin. In addition to peptides, nutrients can play a key role on neuronal activity. Very little is known about nutrient sensing in olfactory areas. Nutrients, such as carbohydrates, amino acids, and lipids, could play a key role in modulating olfactory sensitivity to adjust feeding behavior according to metabolic need. Here we summarize recent findings on nutrient-sensing neurons in olfactory areas and delineate the limits of our knowledge on this topic. The present review opens new lines of investigations on the relationship between olfaction and food intake, which could contribute to determining the etiology of metabolic disorders.
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Affiliation(s)
- A-Karyn Julliard
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/Centre National de la Recherche Scientifique UMR5292 Team Olfaction: From Coding to MemoryLyon, France
| | - Dolly Al Koborssy
- Department of Biological Science, Florida State UniversityTallahassee, FL, United States.,Program in Neuroscience, Florida State UniversityTallahassee, FL, United States
| | - Debra A Fadool
- Department of Biological Science, Florida State UniversityTallahassee, FL, United States.,Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Institute of Molecular Biophysics, Florida State UniversityTallahassee, FL, United States
| | - Brigitte Palouzier-Paulignan
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/Centre National de la Recherche Scientifique UMR5292 Team Olfaction: From Coding to MemoryLyon, France
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14
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Venom-derived peptide inhibitors of voltage-gated potassium channels. Neuropharmacology 2017; 127:124-138. [PMID: 28689025 DOI: 10.1016/j.neuropharm.2017.07.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/02/2017] [Accepted: 07/04/2017] [Indexed: 12/11/2022]
Abstract
Voltage-gated potassium channels play a key role in human physiology and pathology. Reflecting their importance, numerous channelopathies have been characterised that arise from mutations in these channels or from autoimmune attack on the channels. Voltage-gated potassium channels are also the target of a broad range of peptide toxins from venomous organisms, including sea anemones, scorpions, spiders, snakes and cone snails; many of these peptides bind to the channels with high potency and selectivity. In this review we describe the various classes of peptide toxins that block these channels and illustrate the broad range of three-dimensional structures that support channel blockade. The therapeutic opportunities afforded by these peptides are also highlighted. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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15
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Bell GA, Fadool DA. Awake, long-term intranasal insulin treatment does not affect object memory, odor discrimination, or reversal learning in mice. Physiol Behav 2017; 174:104-113. [PMID: 28259806 PMCID: PMC5639911 DOI: 10.1016/j.physbeh.2017.02.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 02/23/2017] [Accepted: 02/28/2017] [Indexed: 12/17/2022]
Abstract
Intranasal insulin delivery is currently being used in clinical trials to test for improvement in human memory and cognition, and in particular, for lessening memory loss attributed to neurodegenerative diseases. Studies have reported the effects of short-term intranasal insulin treatment on various behaviors, but less have examined long-term effects. The olfactory bulb contains the highest density of insulin receptors in conjunction with the highest level of insulin transport within the brain. Previous research from our laboratory has demonstrated that acute insulin intranasal delivery (IND) enhanced both short- and long-term memory as well as increased two-odor discrimination in a two-choice paradigm. Herein, we investigated the behavioral and physiological effects of chronic insulin IND. Adult, male C57BL6/J mice were intranasally treated with 5μg/μl of insulin twice daily for 30 and 60days. Metabolic assessment indicated no change in body weight, caloric intake, or energy expenditure following chronic insulin IND, but an increase in the frequency of meal bouts selectively in the dark cycle. Unlike acute insulin IND, which has been shown to cause enhanced performance in odor habituation/dishabituation and two-odor discrimination tasks in mice, chronic insulin IND did not enhance olfactometry-based odorant discrimination or olfactory reversal learning. In an object memory recognition task, insulin IND-treated mice did not perform differently than controls, regardless of task duration. Biochemical analyses of the olfactory bulb revealed a modest 1.3 fold increase in IR kinase phosphorylation but no significant increase in Kv1.3 phosphorylation. Substrate phosphorylation of IR kinase downstream effectors (MAPK/ERK and Akt signaling) proved to be highly variable. These data indicate that chronic administration of insulin IND in mice fails to enhance olfactory ability, object memory recognition, or a majority of systems physiology metabolic factors - as reported to elicit a modulatory effect with acute administration. This leads to two alternative interpretations regarding long-term insulin IND in mice: 1) It causes an initial stage of insulin resistance to dampen the behaviors that would normally be modulated under acute insulin IND, but ability to clear a glucose challenge is still retained, or 2) There is a lack of behavioral modulation at high concentration of insulin attributed to the twice daily intervals of hyperinsulinemia caused by insulin IND administration without any insulin resistance, per se.
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Affiliation(s)
- Genevieve A Bell
- Department of Biological Science and Program in Neuroscience, The Florida State University, Tallahassee, FL 32306-4295, United States
| | - Debra Ann Fadool
- Department of Biological Science and Program in Neuroscience, The Florida State University, Tallahassee, FL 32306-4295, United States; Institute of Molecular Biophysics, The Florida State University, Tallahassee, FL 32306-4380, United States.
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16
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Rivière S, Soubeyre V, Jarriault D, Molinas A, Léger-Charnay E, Desmoulins L, Grebert D, Meunier N, Grosmaitre X. High Fructose Diet inducing diabetes rapidly impacts olfactory epithelium and behavior in mice. Sci Rep 2016; 6:34011. [PMID: 27659313 PMCID: PMC5034277 DOI: 10.1038/srep34011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 09/06/2016] [Indexed: 02/06/2023] Open
Abstract
Type 2 Diabetes (T2D), a major public health issue reaching worldwide epidemic, has been correlated with lower olfactory abilities in humans. As olfaction represents a major component of feeding behavior, its alteration may have drastic consequences on feeding behaviors that may in turn aggravates T2D. In order to decipher the impact of T2D on the olfactory epithelium, we fed mice with a high fructose diet (HFruD) inducing early diabetic state in 4 to 8 weeks. After only 4 weeks of this diet, mice exhibited a dramatic decrease in olfactory behavioral capacities. Consistently, this decline in olfactory behavior was correlated to decreased electrophysiological responses of olfactory neurons recorded as a population and individually. Our results demonstrate that, in rodents, olfaction is modified by HFruD-induced diabetes. Functional, anatomical and behavioral changes occurred in the olfactory system at a very early stage of the disease.
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Affiliation(s)
- Sébastien Rivière
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Vanessa Soubeyre
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - David Jarriault
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Adrien Molinas
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Elise Léger-Charnay
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Lucie Desmoulins
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Denise Grebert
- INRA, UR1197 Neurobiologie de l'Olfaction et Modélisation en Imagerie, Domaine de Vilvert, F-78350 Jouy-en-Josas, IFR 144 Neuro-Sud Paris, France
| | - Nicolas Meunier
- INRA, UR1197 Neurobiologie de l'Olfaction et Modélisation en Imagerie, Domaine de Vilvert, F-78350 Jouy-en-Josas, IFR 144 Neuro-Sud Paris, France.,Université de Versailles Saint Quentin en Yvelines, F-78000 Versailles, France
| | - Xavier Grosmaitre
- CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne-Franche Comté, UMR Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
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17
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Kovach CP, Al Koborssy D, Huang Z, Chelette BM, Fadool JM, Fadool DA. Mitochondrial Ultrastructure and Glucose Signaling Pathways Attributed to the Kv1.3 Ion Channel. Front Physiol 2016; 7:178. [PMID: 27242550 PMCID: PMC4871887 DOI: 10.3389/fphys.2016.00178] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/04/2016] [Indexed: 12/20/2022] Open
Abstract
Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3−∕−) results in “Super-smeller” mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3−∕− mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3−∕− male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3−∕− mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3−∕− mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very interested to understand how targeted disruption of the Kv1.3 channel in the OB can modify TEE. Our study demonstrates that Kv1.3 regulates mitochondrial structure and alters glucose utilization; two important metabolic changes that could drive whole system changes in metabolism initiated at the OB.
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Affiliation(s)
- Christopher P Kovach
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA
| | - Dolly Al Koborssy
- Program in Neuroscience, Florida State University Tallahassee, FL, USA
| | - Zhenbo Huang
- Program in Neuroscience, Florida State University Tallahassee, FL, USA
| | | | - James M Fadool
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA
| | - Debra A Fadool
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA; Institute of Molecular Biophysics, Florida State UniversityTallahassee, FL, USA
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18
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Spear JM, Koborssy DA, Schwartz AB, Johnson AJ, Audhya A, Fadool DA, Stagg SM. Kv1.3 contains an alternative C-terminal ER exit motif and is recruited into COPII vesicles by Sec24a. BMC BIOCHEMISTRY 2015; 16:16. [PMID: 26156069 PMCID: PMC4497498 DOI: 10.1186/s12858-015-0045-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 06/26/2015] [Indexed: 12/11/2022]
Abstract
Background Potassium channels play a fundamental role in resetting the resting membrane potential of excitable cells. Determining the intracellular trafficking and localization mechanisms of potassium channels provides a platform to fully characterize their maturation and functionality. Previous investigations have discovered residues or motifs that exist in their primary structure, which directly promote anterograde trafficking of nascent potassium channels. Recently, a non-conical di-acidic motif (E483/484) has been discovered in the C-terminus of the mammalian homologue of the Shaker voltage-gated potassium channel subfamily member 3 (Kv1.3), and was shown to disrupt the anterograde trafficking of Kv1.3. Results We have further investigated the intracellular trafficking requirements of Kv1.3 both in vivo and in vitro. First, three alternative C-terminal acidic residues, E443, E445, E447 were probed for their involvement within the early secretory pathway of Kv1.3. Single point (E443A, E445A, and E447A) and double point (E443A-E445A, E445A-E447A) mutations exhibited no significant changes in their endoplasmic reticulum (ER) retention. The triple point mutant E443A-E445A-E447A displayed a modest ER retention while deletion of the C-terminus showed dramatic ER retention. Second, we demonstrate in vivo the requirement for the Sec24a isoform to confer anterograde trafficking using a siRNA knockdown assay. Third, we show in vitro the association of recombinantly expressed Kv1.3 and Sec24a proteins. Conclusion These results expand upon previous studies aimed at deciphering the Kv1.3 secretory trafficking mechanisms and further show in vitro evidence of the association between Kv1.3 and the COPII cargo adaptor subunit isoform Sec24a. Electronic supplementary material The online version of this article (doi:10.1186/s12858-015-0045-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John M Spear
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL, 32306, USA.
| | - Dolly Al Koborssy
- Program in Neuroscience, Florida State University, 1107 West Call Street, Tallahassee, FL, 32306, USA.
| | - Austin B Schwartz
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL, 32306, USA.
| | - Adam J Johnson
- Biomolecular Chemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA.
| | - Anjon Audhya
- Biomolecular Chemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA.
| | - Debra A Fadool
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL, 32306, USA. .,Program in Neuroscience, Florida State University, 1107 West Call Street, Tallahassee, FL, 32306, USA. .,Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL, 32306, USA.
| | - Scott M Stagg
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL, 32306, USA. .,Department of Chemistry and Biochemistry, Florida State University, 91 Chieftan Way, Tallahassee, FL, 32306, USA.
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19
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Soria-Gomez E, Bellocchio L, Marsicano G. New insights on food intake control by olfactory processes: the emerging role of the endocannabinoid system. Mol Cell Endocrinol 2014; 397:59-66. [PMID: 25261796 DOI: 10.1016/j.mce.2014.09.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/22/2014] [Accepted: 09/22/2014] [Indexed: 01/06/2023]
Abstract
The internal state of the organism is an important modulator of perception and behavior. The link between hunger, olfaction and feeding behavior is one of the clearest examples of these connections. At the neurobiological level, olfactory circuits are the targets of several signals (i.e. hormones and nutrients) involved in energy balance. This indicates that olfactory areas are potential sensors of the internal state of the organism. Thus, the aim of this manuscript is to review the literature showing the interplay between metabolic signals in olfactory circuits and its impact on food intake.
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Affiliation(s)
- Edgar Soria-Gomez
- INSERM, U862 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France.
| | - Luigi Bellocchio
- Dept. of Biochemistry and Molecular Biology I, Sch. of Biology, Complutense Univ. and CIBERNED, Madrid, Spain
| | - Giovanni Marsicano
- INSERM, U862 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France
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20
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Al Koborssy D, Palouzier-Paulignan B, Salem R, Thevenet M, Romestaing C, Julliard AK. Cellular and molecular cues of glucose sensing in the rat olfactory bulb. Front Neurosci 2014; 8:333. [PMID: 25400540 PMCID: PMC4212682 DOI: 10.3389/fnins.2014.00333] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 10/03/2014] [Indexed: 11/13/2022] Open
Abstract
In the brain, glucose homeostasis of extracellular fluid is crucial to the point that systems specifically dedicated to glucose sensing are found in areas involved in energy regulation and feeding behavior. Olfaction is a major sensory modality regulating food consumption. Nutritional status in turn modulates olfactory detection. Recently it has been proposed that some olfactory bulb (OB) neurons respond to glucose similarly to hypothalamic neurons. However, the precise molecular cues governing glucose sensing in the OB are largely unknown. To decrypt these molecular mechanisms, we first used immunostaining to demonstrate a strong expression of two neuronal markers of glucose-sensitivity, insulin-dependent glucose transporter type 4 (GLUT4), and sodium glucose co-transporter type 1 (SGLT1) in specific OB layers. We showed that expression and mapping of GLUT4 but not SGLT1 were feeding state-dependent. In order to investigate the impact of metabolic status on the delivery of blood-borne glucose to the OB, we measured extracellular fluid glucose concentration using glucose biosensors simultaneously in the OB and cortex of anesthetized rats. We showed that glucose concentration in the OB is higher than in the cortex, that metabolic steady-state glucose concentration is independent of feeding state in the two brain areas, and that acute changes in glycemic conditions affect bulbar glucose concentration alone. These data provide new evidence of a direct relationship between the OB and peripheral metabolism, and emphasize the importance of glucose for the OB network, providing strong arguments toward establishing the OB as a glucose-sensing organ.
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Affiliation(s)
- Dolly Al Koborssy
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Brigitte Palouzier-Paulignan
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Rita Salem
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Marc Thevenet
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Caroline Romestaing
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés CNRS 5023, University Lyon 1, Bâtiments Darwin C and Forel Villeurbanne, France
| | - A Karyn Julliard
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
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21
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Aimé P, Palouzier-Paulignan B, Salem R, Al Koborssy D, Garcia S, Duchamp C, Romestaing C, Julliard AK. Modulation of olfactory sensitivity and glucose-sensing by the feeding state in obese Zucker rats. Front Behav Neurosci 2014; 8:326. [PMID: 25278856 PMCID: PMC4166364 DOI: 10.3389/fnbeh.2014.00326] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 09/01/2014] [Indexed: 12/13/2022] Open
Abstract
The Zucker fa/fa rat has been widely used as an animal model to study obesity, since it recapitulates most of its behavioral and metabolic dysfunctions, such as hyperphagia, hyperglycemia and insulin resistance. Although it is well established that olfaction is under nutritional and hormonal influences, little is known about the impact of metabolic dysfunctions on olfactory performances and glucose-sensing in the olfactory system of the obese Zucker rat. In the present study, using a behavioral paradigm based on a conditioned olfactory aversion, we have shown that both obese and lean Zucker rats have a better olfactory sensitivity when they are fasted than when they are satiated. Interestingly, the obese Zucker rats displayed a higher olfactory sensitivity than their lean controls. By investigating the molecular mechanisms involved in glucose-sensing in the olfactory system, we demonstrated that sodium-coupled glucose transporters 1 (SGLT1) and insulin dependent glucose transporters 4 (GLUT4) are both expressed in the olfactory bulb (OB). By comparing the expression of GLUT4 and SGLT1 in OB of obese and lean Zucker rats, we found that only SGLT1 is regulated in genotype-dependent manner. Next, we used glucose oxidase biosensors to simultaneously measure in vivo the extracellular fluid glucose concentrations ([Gluc]ECF) in the OB and the cortex. Under metabolic steady state, we have determined that the OB contained twice the amount of glucose found in the cortex. In both regions, the [Gluc]ECF was 2 fold higher in obese rats compared to their lean controls. Under induced dynamic glycemia conditions, insulin injection produced a greater decrease of [Gluc]ECF in the OB than in the cortex. Glucose injection did not affect OB [Gluc]ECF in Zucker fa/fa rats. In conclusion, these results emphasize the importance of glucose for the OB network function and provide strong arguments towards establishing the OB glucose-sensing as a key factor for sensory olfactory processing.
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Affiliation(s)
- Pascaline Aimé
- Team "Olfaction: From Coding to Memory", Lyon Neuroscience Center, INSERM U1028-CNRS 5292- Université Lyon1 Lyon, France
| | - Brigitte Palouzier-Paulignan
- Team "Olfaction: From Coding to Memory", Lyon Neuroscience Center, INSERM U1028-CNRS 5292- Université Lyon1 Lyon, France
| | - Rita Salem
- Team "Olfaction: From Coding to Memory", Lyon Neuroscience Center, INSERM U1028-CNRS 5292- Université Lyon1 Lyon, France
| | - Dolly Al Koborssy
- Team "Olfaction: From Coding to Memory", Lyon Neuroscience Center, INSERM U1028-CNRS 5292- Université Lyon1 Lyon, France
| | - Samuel Garcia
- Team "Olfaction: From Coding to Memory", Lyon Neuroscience Center, INSERM U1028-CNRS 5292- Université Lyon1 Lyon, France
| | - Claude Duchamp
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés CNRS 5023, Villeurbanne, France
| | - Caroline Romestaing
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés CNRS 5023, Villeurbanne, France
| | - A Karyn Julliard
- Team "Olfaction: From Coding to Memory", Lyon Neuroscience Center, INSERM U1028-CNRS 5292- Université Lyon1 Lyon, France
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22
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Ng SF, Lin RCY, Maloney CA, Youngson NA, Owens JA, Morris MJ. Paternal high-fat diet consumption induces common changes in the transcriptomes of retroperitoneal adipose and pancreatic islet tissues in female rat offspring. FASEB J 2014; 28:1830-41. [PMID: 24421403 DOI: 10.1096/fj.13-244046] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We previously showed that paternal high-fat diet (HFD) consumption programs β-cell dysfunction in female rat offspring, together with transcriptome alterations in islets. Here we investigated the retroperitoneal white adipose tissue (RpWAT) transcriptome using gene and pathway enrichment and pathway analysis to determine whether commonly affected network topologies exist between these two metabolically related tissues. In RpWAT, 5108 genes were differentially expressed due to a paternal HFD; the top 5 significantly enriched networks identified by pathway analysis in offspring of HFD fathers compared with those of fathers fed control diet were: mitochondrial and cellular response to stress, telomerase signaling, cell death and survival, cell cycle, cellular growth and proliferation, and cancer. A total of 187 adipose olfactory receptor genes were down-regulated. Interrogation against the islet transcriptome identified specific gene networks and pathways, including olfactory receptor genes that were similarly affected in both tissues (411 common genes, P<0.05). In particular, we highlight a common molecular network, cell cycle and cancer, with the same hub gene, Myc, suggesting early onset developmental changes that persist, shared responses to programmed systemic factors, or crosstalk between tissues. Thus, paternal HFD consumption triggers unique gene signatures, consistent with premature aging and chronic degenerative disorders, in both RpWAT and pancreatic islets of daughters.
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Affiliation(s)
- Sheau-Fang Ng
- 1Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia, 2052.
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23
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Ishii T, Warabi E, Siow RCM, Mann GE. Sequestosome1/p62: a regulator of redox-sensitive voltage-activated potassium channels, arterial remodeling, inflammation, and neurite outgrowth. Free Radic Biol Med 2013; 65:102-116. [PMID: 23792273 DOI: 10.1016/j.freeradbiomed.2013.06.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/06/2013] [Accepted: 06/07/2013] [Indexed: 12/14/2022]
Abstract
Sequestosome1/p62 (SQSTM1) is an oxidative stress-inducible protein regulated by the redox-sensitive transcription factor Nrf2. It is not an antioxidant but known as a multifunctional regulator of cell signaling with an ability to modulate targeted or selective degradation of proteins through autophagy. SQSTM1 implements these functions through physical interactions with different types of proteins including atypical PKCs, nonreceptor-type tyrosine kinase p56(Lck) (Lck), polyubiquitin, and autophagosomal factor LC3. One of the notable physiological functions of SQSTM1 is the regulation of redox-sensitive voltage-gated potassium (Kv) channels which are composed of α and β subunits: (Kvα)4 (Kvβ)4. Previous studies have established that SQSTM1 scaffolds PKCζ, enhancing phosphorylation of Kvβ which induces inhibition of pulmonary arterial Kv1.5 channels under acute hypoxia. Recent studies reveal that Lck indirectly interacts with Kv1.3 α subunits and plays a key role in acute hypoxia-induced Kv1.3 channel inhibition in T lymphocytes. Kv1.3 channels provide a signaling platform to modulate the migration and proliferation of arterial smooth muscle cells and activation of T lymphocytes, and hence have been recognized as a therapeutic target for treatment of restenosis and autoimmune diseases. In this review, we focus on the functional interactions of SQSTM1 with Kv channels through two key partners aPKCs and Lck. Furthermore, we provide molecular insights into the functions of SQSTM1 in suppression of proliferation of arterial smooth muscle cells and neointimal hyperplasia following carotid artery ligation, in T lymphocyte differentiation and activation, and in NGF-induced neurite outgrowth in PC12 cells.
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Affiliation(s)
- Tetsuro Ishii
- School of Medicine, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki, 305-8575, Japan.
| | - Eiji Warabi
- School of Medicine, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki, 305-8575, Japan
| | - Richard C M Siow
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence, School of Medicine, King's College London, London SE1 9NH, UK
| | - Giovanni E Mann
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence, School of Medicine, King's College London, London SE1 9NH, UK
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Duque A, Gazula VR, Kaczmarek LK. Expression of Kv1.3 potassium channels regulates density of cortical interneurons. Dev Neurobiol 2013; 73:841-55. [PMID: 23821603 DOI: 10.1002/dneu.22105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 06/19/2013] [Accepted: 06/21/2013] [Indexed: 01/27/2023]
Abstract
The Kv1.3 protein is a member of the large family of voltage-dependent K+ subunits (Kv channels), which assemble to form tetrameric membrane-spanning channels that provide a selective pore for the conductance of K+ across the cell membrane. Kv1.3 differs from most other Kv channels in that deletion of Kv1.3 gene produces very striking changes in development and structure of the olfactory bulb, where Kv1.3 is expressed at high levels, resulting in a lower threshold for detection of odors, an increased number of synaptic glomeruli and alterations in the levels of a variety of neuronal signaling molecules. Because Kv1.3 is also expressed in the cerebral cortex, we have now examined the effects of deletion of the Kv1.3 gene on the expression of interneuron populations of the cerebral cortex. Using unbiased stereology we found an increase in the number of parvalbumin (PV) cells in whole cerebral cortex of Kv1.3-/- mice relative to that in wild-type mice, and a decrease in the number of calbindin (CB), calretinin (CR), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), and somatostatin (SOM) interneurons. These changes are accompanied by a decrease in the cortical volume such that the cell density of PV interneurons is significantly increased and that of SOM neurons is decreased in Kv1.3-/- animals. Our studies suggest that, as in the olfactory bulb, Kv1.3 plays a unique role in neuronal differentiation and/or survival of interneuron populations and that expression of Kv1.3 is required for normal cortical function.
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Affiliation(s)
- Alvaro Duque
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, 06520
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25
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Woods SC. From conditioned hypoglycemia to obesity: following the data. Physiol Behav 2013; 121:19-24. [PMID: 23352822 DOI: 10.1016/j.physbeh.2013.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/03/2013] [Indexed: 01/24/2023]
Abstract
While a graduate student in the late 1960s I trained rats to lower their blood glucose in response to an arbitrary cue, a phenomenon called conditioned hypoglycemia. Over many years as my colleagues and I attempted to understand the underlying physiology of conditioned insulin secretion and conditioned hypoglycemia, it became clear that there were many implications that were highly important, including the entry of insulin into the brain, the existence of insulin receptors in certain brain areas, neural reflexes that project to insulin-secreting B-cells in the pancreas, the entrainment of those reflexes to improve the efficiency of meal-taking, and the possibility of adiposity signals from the body to the brain that influence behavior and metabolism. This article summarizes how we tackled each of these areas of research.
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Affiliation(s)
- Stephen C Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, 2170 East Galbraith Road, Cincinnati, OH 45237, USA.
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Palouzier-Paulignan B, Lacroix MC, Aimé P, Baly C, Caillol M, Congar P, Julliard AK, Tucker K, Fadool DA. Olfaction under metabolic influences. Chem Senses 2012; 37:769-97. [PMID: 22832483 PMCID: PMC3529618 DOI: 10.1093/chemse/bjs059] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Recently published work and emerging research efforts have suggested that the olfactory system is intimately linked with the endocrine systems that regulate or modify energy balance. Although much attention has been focused on the parallels between taste transduction and neuroendocrine controls of digestion due to the novel discovery of taste receptors and molecular components shared by the tongue and gut, the equivalent body of knowledge that has accumulated for the olfactory system, has largely been overlooked. During regular cycles of food intake or disorders of endocrine function, olfaction is modulated in response to changing levels of various molecules, such as ghrelin, orexins, neuropeptide Y, insulin, leptin, and cholecystokinin. In view of the worldwide health concern regarding the rising incidence of diabetes, obesity, and related metabolic disorders, we present a comprehensive review that addresses the current knowledge of hormonal modulation of olfactory perception and how disruption of hormonal signaling in the olfactory system can affect energy homeostasis.
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Affiliation(s)
- Brigitte Palouzier-Paulignan
- Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028/CNRS 5292, Université de Lyon150 Ave. Tony Garnier, 69366, Lyon, Cedex 07,France
- Equal contribution
| | - Marie-Christine Lacroix
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
- Equal contribution
| | - Pascaline Aimé
- Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028/CNRS 5292, Université de Lyon150 Ave. Tony Garnier, 69366, Lyon, Cedex 07,France
| | - Christine Baly
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
| | - Monique Caillol
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
| | - Patrice Congar
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
| | - A. Karyn Julliard
- Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028/CNRS 5292, Université de Lyon150 Ave. Tony Garnier, 69366, Lyon, Cedex 07,France
| | - Kristal Tucker
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of MedicinePittsburgh, PA 15261USAand
| | - Debra Ann Fadool
- Department of Biological Science, Programs in Neuroscience and Molecular Biophysics, The Florida State UniversityTallahassee, FL 32306-4295USA
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Tucker KR, Godbey SJ, Thiebaud N, Fadool DA. Olfactory ability and object memory in three mouse models of varying body weight, metabolic hormones, and adiposity. Physiol Behav 2012; 107:424-32. [PMID: 22995978 PMCID: PMC3513555 DOI: 10.1016/j.physbeh.2012.09.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 06/18/2012] [Accepted: 09/11/2012] [Indexed: 01/15/2023]
Abstract
Physiological and nutritional state can modify sensory ability and perception through hormone signaling. Obesity and related metabolic disorders present a chronic imbalance in hormonal signaling that could impact sensory systems. In the olfactory system, external chemical cues are transduced into electrical signals to encode information. It is becoming evident that this system can also detect internal chemical cues in the form of molecules of energy homeostasis and endocrine hormones, whereby neurons of the olfactory system are modulated to change animal behavior towards olfactory cues. We hypothesized that chronic imbalance in hormonal signaling and energy homeostasis due to obesity would thereby disrupt olfactory behaviors in mice. To test this idea, we utilized three mouse models of varying body weight, metabolic hormones, and visceral adiposity - 1) C57BL6/J mice maintained on a condensed-milk based, moderately high-fat diet (MHF) of 32% fat for 6 months as the diet-induced obesity model, 2) an obesity-resistant, lean line of mice due to a gene-targeted deletion of a voltage-dependent potassium channel (Kv 1.3-null), and 3) a genetic model of obesity as a result of a gene-targeted deletion of the melanocortin 4 receptor (MC4R-null). Diet-induced obese (DIO) mice failed to find a fatty-scented hidden peanut butter cracker, based solely on olfactory cues, any faster than an unscented hidden marble, initially suggesting general anosmia. However, when these DIO mice were challenged to find a sweet-scented hidden chocolate candy, they had no difficulty. Furthermore, DIO mice were able to discriminate between fatty acids that differ by a single double bond and are components of the MHF diet (linoleic and oleic acid) in a habituation-dishabituation paradigm. Obesity-resistant, Kv1.3-null mice exhibited no change in scented object retrieval when placed on the MHF-diet, nor did they perform differently than wild-type mice in parallel habituation-dishabituation paradigms of fatty food-related odor components. Genetically obese, MC4R-null mice successfully found hidden scented objects, but did so more slowly than lean, wild-type mice, in an object-dependent fashion. In habituation-dishabituation trials of general odorants, MC4R-null mice failed to discriminate a novel odor, but were able to distinguish two fatty acids. Object memory recognition tests for short- and long-term memory retention demonstrated that maintenance on the MHF diet did not modify the ability to perform these tasks independent of whether mice became obese or were resistant to weight gain (Kv1.3-null), however, the genetically predisposed obese mice (MC4R-null) failed the long-term object memory recognition performed at 24h. These results demonstrate that even though both the DIO mice and genetically predisposed obese mice are obese, they vary in the degree to which they exhibit behavioral deficits in odor detection, odor discrimination, and long-term memory.
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Affiliation(s)
- Kristal R Tucker
- Department of Biological Science, 319 Stadium Drive, Suite 3008, King Life Sciences Building, The Florida State University, Tallahassee, FL 32306-4295, United States; Program in Neuroscience, 319 Stadium Drive, Suite 3008, King Life Sciences Building, The Florida State University, Tallahassee, FL 32306-4295, United States.
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28
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Abstract
Gene-targeted deletion of the voltage-gated potassium channel, Kv1.3 (Kv1.3-/-), increases olfactory sensitivity and discriminatory ability, and causes resistance to diet-induced obesity (DIO) in mice. The present study aimed to determine whether the enhanced olfactory ability of the Kv1.3-/- mouse contributes to the resistance to DIO. Kv1.3+/+ and Kv1.3-/- mice were subject to bilateral olfactory bulbectomy (OBX) or sham surgery at 9 weeks of age and placed on either a control chow diet or a 32% moderately high-fat diet (MHF). Caloric and water intake, locomotor activity and oxygen consumption were monitored after 5 weeks of diet treatment. At the end of 26 weeks of diet treatment, fat pad weight and blood chemistry were evaluated. Kv1.3+/+ mice exhibited a significant increase in weight, adiposity, fasting glucose and fasting leptin in response to the MHF-diet, with or without OBX. When treated with a MHF-diet, Kv1.3-/- mice gained significantly less weight than Kv1.3+/+ mice and exhibited a significant increase in light phase metabolism. OBX of Kv1.3-/- mice prevented the resistance to DIO and concomitant up-regulation of light phase metabolism at the same time as decreasing dark phase metabolism and total energy expenditure. These findings suggest that pathways activated in Kv1.3-/- that increased energy expenditure and led to resistance to DIO are olfactory bulb dependent. Thus, these findings add to a growing body of evidence suggesting that the olfactory system can modulate the pathways involved in the regulation of energy balance.
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Affiliation(s)
- K Tucker
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.
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29
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Corthell JT, Fadool DA, Trombley PQ. Connexin and AMPA receptor expression changes over time in the rat olfactory bulb. Neuroscience 2012; 222:38-48. [PMID: 22813997 DOI: 10.1016/j.neuroscience.2012.06.070] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/21/2012] [Accepted: 06/29/2012] [Indexed: 11/30/2022]
Abstract
Circadian rhythms affect olfaction by an unknown molecular mechanism. Independent of the suprachiasmatic nuclei, the mammalian olfactory bulb (OB) has recently been identified as a circadian oscillator. The electrical activity in the OB was reported to be synchronized to a daily rhythm and the clock gene, Period1, was oscillatory in its expression pattern. Because gap junctions composed of connexin36 and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) have been reported to work together to synchronize firing of action potentials in the OB, we hypothesized that circadian electrical oscillations could be synchronized by daily changes in the expression of connexins and AMPAR subunits (GluR1-4). We examined the OB for the presence of clock genes by polymerase chain reaction (PCR) and whether Period2, connexins, and AMPARs fluctuated across the light/dark cycle by quantitative PCR or SDS-PAGE/Western blot analysis. We observed significant changes in the messenger RNA and protein expression of our targets across 24 or 48 h. Whereas most targets were rhythmic by some measures, only GluR1 mRNA and protein were both rhythmic by the majority of our tests of rhythmicity across all time scales. Differential expression of these synaptic proteins over the light/dark cycle may underlie circadian synchronization of action potential firing in the OB or modify synaptic interactions that would be predicted to impact olfactory coding, such as alteration of granule cell inhibition, increased number of available AMPARs to bind glutamate, or an increased gap junction conductance between mitral/tufted cells.
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Affiliation(s)
- J T Corthell
- Department of Biological Science, The Florida State University, Tallahassee, FL 32306-4340, United States.
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30
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Fadool DA, Tucker K, Pedarzani P. Mitral cells of the olfactory bulb perform metabolic sensing and are disrupted by obesity at the level of the Kv1.3 ion channel. PLoS One 2011; 6:e24921. [PMID: 21966386 PMCID: PMC3178571 DOI: 10.1371/journal.pone.0024921] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 08/19/2011] [Indexed: 12/12/2022] Open
Abstract
Sixty-five percent of Americans are over-weight. While the neuroendocrine controls of energy homeostasis are well known, how sensory systems respond to and are impacted by obesity is scantily understood. The main accepted function of the olfactory system is to provide an internal depiction of our external chemical environment, starting from the detection of chemosensory cues. We hypothesized that the system additionally functions to encode internal chemistry via the detection of chemicals that are important indicators of metabolic state. We here uncovered that the olfactory bulb (OB) subserves as an internal sensor of metabolism via insulin-induced modulation of the potassium channel Kv1.3. Using an adult slice preparation of the olfactory bulb, we found that evoked neural activity in Kv1.3-expressing mitral cells is enhanced following acute insulin application. Insulin mediated changes in mitral cell excitability are predominantly due to the modulation of Kv1.3 channels as evidenced by the lack of effect in slices from Kv1.3-null mice. Moreover, a selective Kv1.3 peptide blocker (ShK186) inhibits more than 80% of the outward current in parallel voltage-clamp studies, whereby insulin significantly decreases the peak current magnitude without altering the kinetics of inactivation or deactivation. Mice that were chronically administered insulin using intranasal delivery approaches exhibited either an elevation in basal firing frequency or fired a single cluster of action potentials. Following chronic administration of the hormone, mitral cells were inhibited by application of acute insulin rather than excited. Mice made obese through a diet of ∼32% fat exhibited prominent changes in mitral cell action potential shape and clustering behavior, whereby the subsequent response to acute insulin stimulation was either attenuated or completely absent. Our results implicate an inappropriate neural function of olfactory sensors following exposure to chronic levels of the hormone insulin (diabetes) or increased body weight (obesity).
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Affiliation(s)
- Debra Ann Fadool
- Program in Neuroscience, The Florida State University, Tallahassee, Florida, United States of America
- Department of Biological Sciences, The Florida State University, Tallahassee, Florida, United States of America
- Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida, United States of America
- * E-mail:
| | - Kristal Tucker
- Program in Neuroscience, The Florida State University, Tallahassee, Florida, United States of America
| | - Paola Pedarzani
- Research Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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Straub SV, Perez SM, Tan B, Coughlan KA, Trebino CE, Cosgrove P, Buxton JM, Kreeger JM, Jackson VM. Pharmacological inhibition of Kv1.3 fails to modulate insulin sensitivity in diabetic mice or human insulin-sensitive tissues. Am J Physiol Endocrinol Metab 2011; 301:E380-90. [PMID: 21586699 DOI: 10.1152/ajpendo.00076.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Genetic ablation of the voltage-gated potassium channel Kv1.3 improves insulin sensitivity and increases metabolic rate in mice. Inhibition of Kv1.3 in mouse adipose and skeletal muscle is reported to increase glucose uptake through increased GLUT4 translocation. Since Kv1.3 represents a novel target for the treatment of diabetes, the present study investigated whether Kv1.3 is functionally expressed in human adipose and skeletal muscle and whether specific pharmacological inhibition of the channel is capable of modulating insulin sensitivity in diabetic mouse models. Voltage-gated K(+) channel currents in human skeletal muscle cells (SkMC) were insensitive to block by the specific Kv1.3 blockers 5-(4-phenoxybutoxy)psoralen (PAP-1) and margatoxin (MgTX). Glucose uptake into SkMC and mouse 3T3-L1 adipocytes was also unaffected by treatment with PAP-1 or MgTX. Kv1.3 protein expression was not observed in human adipose or skeletal muscle from normal and type 2 diabetic donors. To investigate the effect of specific Kv1.3 inhibition on insulin sensitivity in vivo, PAP-1 was administered to hyperglycemic mice either acutely or for 5 days prior to an insulin tolerance test. No effect on insulin sensitivity was observed at free plasma PAP-1 concentrations that are specific for inhibition of Kv1.3. Insulin sensitivity was increased only when plasma concentrations of PAP-1 were sufficient to inhibit other Kv1 channels. Surprisingly, acute inhibition of Kv1.3 in the brain was found to decrease insulin sensitivity in ob/ob mice. Overall, these findings are not supportive of a role for Kv1.3 in the modulation of peripheral insulin sensitivity.
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Affiliation(s)
- Stephen V Straub
- Cardiovascular, Metabolic, and Endocrine Diseases Research Unit, Pfizer, Eastern Point Rd., Groton, CT 06340, USA.
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