1
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Zhou YS, Tao HB, Lv SS, Liang KQ, Shi WY, Liu KY, Li YY, Chen LY, Zhou L, Yin SJ, Zhao QR. Effects of Kv1.3 knockout on pyramidal neuron excitability and synaptic plasticity in piriform cortex of mice. Acta Pharmacol Sin 2024:10.1038/s41401-024-01275-y. [PMID: 38862816 DOI: 10.1038/s41401-024-01275-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 03/24/2024] [Indexed: 06/13/2024] Open
Abstract
Kv1.3 belongs to the voltage-gated potassium (Kv) channel family, which is widely expressed in the central nervous system and associated with a variety of neuropsychiatric disorders. Kv1.3 is highly expressed in the olfactory bulb and piriform cortex and involved in the process of odor perception and nutrient metabolism in animals. Previous studies have explored the function of Kv1.3 in olfactory bulb, while the role of Kv1.3 in piriform cortex was less known. In this study, we investigated the neuronal changes of piriform cortex and feeding behavior after smell stimulation, thus revealing a link between the olfactory sensation and body weight in Kv1.3 KO mice. Coronal slices including the anterior piriform cortex were prepared, whole-cell recording and Ca2+ imaging of pyramidal neurons were conducted. We showed that the firing frequency evoked by depolarization pulses and Ca2+ influx evoked by high K+ solution were significantly increased in pyramidal neurons of Kv1.3 knockout (KO) mice compared to WT mice. Western blotting and immunofluorescence analyses revealed that the downstream signaling molecules CaMKII and PKCα were activated in piriform cortex of Kv1.3 KO mice. Pyramidal neurons in Kv1.3 KO mice exhibited significantly reduced paired-pulse ratio and increased presynaptic Cav2.1 expression, proving that the presynaptic vesicle release might be elevated by Ca2+ influx. Using Golgi staining, we found significantly increased dendritic spine density of pyramidal neurons in Kv1.3 KO mice, supporting the stronger postsynaptic responses in these neurons. In olfactory recognition and feeding behavior tests, we showed that Kv1.3 conditional knockout or cannula injection of 5-(4-phenoxybutoxy) psoralen, a Kv1.3 channel blocker, in piriform cortex both elevated the olfactory recognition index and altered the feeding behavior in mice. In summary, Kv1.3 is a key molecule in regulating neuronal activity of the piriform cortex, which may lay a foundation for the treatment of diseases related to piriform cortex and olfactory detection.
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Affiliation(s)
- Yong-Sheng Zhou
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Hao-Bo Tao
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Si-Si Lv
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Ke-Qin Liang
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Wen-Yi Shi
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Ke-Yi Liu
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Yun-Yun Li
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Lv-Yi Chen
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Ling Zhou
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China
| | - Shi-Jin Yin
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China.
| | - Qian-Ru Zhao
- Department of Chemical Biology, School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan, 430074, China.
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2
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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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3
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Cheng S, Jiang D, Lan X, Liu K, Fan C. Voltage-gated potassium channel 1.3: A promising molecular target in multiple disease therapy. Biomed Pharmacother 2024; 175:116651. [PMID: 38692062 DOI: 10.1016/j.biopha.2024.116651] [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: 02/20/2024] [Revised: 04/21/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024] Open
Abstract
Voltage-gated potassium channel 1.3 (Kv1.3) has emerged as a pivotal player in numerous biological processes and pathological conditions, sparking considerable interest as a potential therapeutic target across various diseases. In this review, we present a comprehensive examination of Kv1.3 channels, highlighting their fundamental characteristics and recent advancements in utilizing Kv1.3 inhibitors for treating autoimmune disorders, neuroinflammation, and cancers. Notably, Kv1.3 is prominently expressed in immune cells and implicated in immune responses and inflammation associated with autoimmune diseases and chronic inflammatory conditions. Moreover, its aberrant expression in certain tumors underscores its role in cancer progression. While preclinical studies have demonstrated the efficacy of Kv1.3 inhibitors, their clinical translation remains pending. Molecular imaging techniques offer promising avenues for tracking Kv1.3 inhibitors and assessing their therapeutic efficacy, thereby facilitating their development and clinical application. Challenges and future directions in Kv1.3 inhibitor research are also discussed, emphasizing the significant potential of targeting Kv1.3 as a promising therapeutic strategy across a spectrum of diseases.
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Affiliation(s)
- Sixuan Cheng
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; Hubei Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Dawei Jiang
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; Hubei Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Xiaoli Lan
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; Hubei Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Kun Liu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
| | - Cheng Fan
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
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4
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Kim H, Choi MR, Jeon SH, Jang Y, Yang YD. Pathophysiological Roles of Ion Channels in Epidermal Cells, Immune Cells, and Sensory Neurons in Psoriasis. Int J Mol Sci 2024; 25:2756. [PMID: 38474002 DOI: 10.3390/ijms25052756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 02/23/2024] [Accepted: 02/25/2024] [Indexed: 03/14/2024] Open
Abstract
Psoriasis is a chronic inflammatory skin disease characterized by the rapid abnormal growth of skin cells in the epidermis, driven by an overactive immune system. Consequently, a complex interplay among epidermal cells, immune cells, and sensory neurons contributes to the development and progression of psoriasis. In these cellular contexts, various ion channels, such as acetylcholine receptors, TRP channels, Ca2+ release-activated channels, chloride channels, and potassium channels, each serve specific functions to maintain the homeostasis of the skin. The dysregulation of ion channels plays a major role in the pathophysiology of psoriasis, affecting various aspects of epidermal cells, immune responses, and sensory neuron signaling. Impaired function of ion channels can lead to altered calcium signaling, inflammation, proliferation, and sensory signaling, all of which are central features of psoriasis. This overview summarizes the pathophysiological roles of ion channels in epidermal cells, immune cells, and sensory neurons during early and late psoriatic processes, thereby contributing to a deeper understanding of ion channel involvement in the interplay of psoriasis and making a crucial advance toward more precise and personalized approaches for psoriasis treatment.
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Affiliation(s)
- Hyungsup Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Mi Ran Choi
- Laboratory Animal Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Seong Ho Jeon
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon 11160, Republic of Korea
| | - Yongwoo Jang
- Department of Pharmacology, College of Medicine, Hanyang University, Seoul 04736, Republic of Korea
| | - Young Duk Yang
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon 11160, Republic of Korea
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5
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Chandy KG, Sanches K, Norton RS. Structure of the voltage-gated potassium channel K V1.3: Insights into the inactivated conformation and binding to therapeutic leads. Channels (Austin) 2023; 17:2253104. [PMID: 37695839 PMCID: PMC10496531 DOI: 10.1080/19336950.2023.2253104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/13/2023] Open
Abstract
The voltage-gated potassium channel KV1.3 is an important therapeutic target for the treatment of autoimmune and neuroinflammatory diseases. The recent structures of KV1.3, Shaker-IR (wild-type and inactivating W434F mutant) and an inactivating mutant of rat KV1.2-KV2.1 paddle chimera (KVChim-W362F+S367T+V377T) reveal that the transition of voltage-gated potassium channels from the open-conducting conformation into the non-conducting inactivated conformation involves the rupture of a key intra-subunit hydrogen bond that tethers the selectivity filter to the pore helix. Breakage of this bond allows the side chains of residues at the external end of the selectivity filter (Tyr447 and Asp449 in KV1.3) to rotate outwards, dilating the outer pore and disrupting ion permeation. Binding of the peptide dalazatide (ShK-186) and an antibody-ShK fusion to the external vestibule of KV1.3 narrows and stabilizes the selectivity filter in the open-conducting conformation, although K+ efflux is blocked by the peptide occluding the pore through the interaction of ShK-Lys22 with the backbone carbonyl of KV1.3-Tyr447 in the selectivity filter. Electrophysiological studies on ShK and the closely-related peptide HmK show that ShK blocks KV1.3 with significantly higher potency, even though molecular dynamics simulations show that ShK is more flexible than HmK. Binding of the anti-KV1.3 nanobody A0194009G09 to the turret and residues in the external loops of the voltage-sensing domain enhances the dilation of the outer selectivity filter in an exaggerated inactivated conformation. These studies lay the foundation to further define the mechanism of slow inactivation in KV channels and can help guide the development of future KV1.3-targeted immuno-therapeutics.
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Affiliation(s)
- K. George Chandy
- LKCMedicine-ICESing Ion Channel Platform, Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Singapore
| | - Karoline Sanches
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, Australia
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6
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López M, Fernández-Real JM, Tomarev SI. Obesity wars: may the smell be with you. Am J Physiol Endocrinol Metab 2023; 324:E569-E576. [PMID: 37166265 PMCID: PMC10259866 DOI: 10.1152/ajpendo.00040.2023] [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: 02/07/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/12/2023]
Abstract
Classically, the regulation of energy balance has been based on central and peripheral mechanisms sensing energy, nutrients, metabolites, and hormonal cues. Several cellular mechanisms at central level, such as hypothalamic AMP-activated protein kinase (AMPK), integrate this information to elicit counterregulatory responses that control feeding, energy expenditure, and glucose homeostasis, among other processes. Recent data have added more complexity to the homeostatic regulation of metabolism by introducing, for example, the key role of "traditional" senses and sensorial information in this complicated network. In this regard, current evidence is showing that olfaction plays a key and bidirectional role in energy homeostasis. Although nutritional status dynamically and profoundly impacts olfactory sensitivity, the sense of smell is involved in food appreciation and selection, as well as in brown adipose tissue (BAT) thermogenesis and substrate utilization, with some newly described actors, such as olfactomedin 2 (OLFM2), likely playing a major role. Thus, olfactory inputs are contributing to the regulation of both sides of the energy balance equation, namely, feeding and energy expenditure (EE), as well as whole body metabolism. Here, we will review the current knowledge and advances about the role of olfaction in the regulation of energy homeostasis.
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Affiliation(s)
- Miguel López
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Spain
| | - José Manuel Fernández-Real
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Spain
- Service of Diabetes, Endocrinology and Nutrition (UDEN), Institut d'Investigació Biomédica de Girona (IDIBGI), Department of Medical Sciences, University of Girona, Girona, Spain
| | - Stanislav I Tomarev
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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7
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Varanita T, Angi B, Scattolini V, Szabo I. Kv1.3 K + Channel Physiology Assessed by Genetic and Pharmacological Modulation. Physiology (Bethesda) 2023; 38:0. [PMID: 35998249 DOI: 10.1152/physiol.00010.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Potassium channels are widespread over all kingdoms and play an important role in the maintenance of cellular ionic homeostasis. Kv1.3 is a voltage-gated potassium channel of the Shaker family with a wide tissue expression and a well-defined pharmacology. In recent decades, experiments mainly based on pharmacological modulation of Kv1.3 have highlighted its crucial contribution to different fundamental processes such as regulation of proliferation, apoptosis, and metabolism. These findings link channel function to various pathologies ranging from autoimmune diseases to obesity and cancer. In the present review, we briefly summarize studies employing Kv1.3 knockout animal models to confirm such roles and discuss the findings in comparison to the results obtained by pharmacological modulation of Kv1.3 in various pathophysiological settings. We also underline how these studies contributed to our understanding of channel function in vivo and propose possible future directions.
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Affiliation(s)
| | - Beatrice Angi
- Department of Biology, University of Padova, Padova, Italy
| | | | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy
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8
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Perszyk EE, Davis XS, Small DM. Olfactory decoding is positively associated with ad libitum food intake in sated humans. Appetite 2023; 180:106351. [PMID: 36270421 DOI: 10.1016/j.appet.2022.106351] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/06/2022]
Abstract
The role of olfaction in eating behavior and body weight regulation is controversial. Here we reanalyzed data from a previous functional magnetic resonance imaging study to test whether central olfactory coding is associated with hunger/satiety state, food intake, and change in body weight over one year in healthy human adults. Since odor quality and category are coded across distributed neural patterns that are not discernible with traditional univariate analyses, we used multi-voxel pattern analyses to decode patterns of brain activation to food versus nonfood odors. We found that decoding accuracies in the piriform cortex and amygdala were greater in the sated compared to hungry state. Sated decoding accuracies in these and other regions were also associated with post-scan ad libitum food intake, but not with weight change. These findings demonstrate that the fidelity of olfactory decoding is influenced by meal consumption and is associated with immediate food intake, but not longer-term body weight regulation.
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Affiliation(s)
- Emily E Perszyk
- Modern Diet and Physiology Research Center, New Haven, CT, 06510, USA; Yale University School of Medicine, Department of Psychiatry, New Haven, CT, 06510, USA.
| | - Xue S Davis
- Modern Diet and Physiology Research Center, New Haven, CT, 06510, USA; Yale University School of Medicine, Department of Psychiatry, New Haven, CT, 06510, USA
| | - Dana M Small
- Modern Diet and Physiology Research Center, New Haven, CT, 06510, USA; Yale University School of Medicine, Department of Psychiatry, New Haven, CT, 06510, USA; Yale University, Department of Psychology, New Haven, CT, 06510, USA.
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9
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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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10
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Tsuneki H, Sugiyama M, Ito T, Sato K, Matsuda H, Onishi K, Yubune K, Matsuoka Y, Nagai S, Yamagishi T, Maeda T, Honda K, Okekawa A, Watanabe S, Yaku K, Okuzaki D, Otsubo R, Nomoto M, Inokuchi K, Nakagawa T, Wada T, Yasui T, Sasaoka T. Food odor perception promotes systemic lipid utilization. Nat Metab 2022; 4:1514-1531. [PMID: 36376564 DOI: 10.1038/s42255-022-00673-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 09/30/2022] [Indexed: 11/16/2022]
Abstract
Food cues during fasting elicit Pavlovian conditioning to adapt for anticipated food intake. However, whether the olfactory system is involved in metabolic adaptations remains elusive. Here we show that food-odor perception promotes lipid metabolism in male mice. During fasting, food-odor stimulation is sufficient to increase serum free fatty acids via adipose tissue lipolysis in an olfactory-memory-dependent manner, which is mediated by the central melanocortin and sympathetic nervous systems. Additionally, stimulation with a food odor prior to refeeding leads to enhanced whole-body lipid utilization, which is associated with increased sensitivity of the central agouti-related peptide system, reduced sympathetic activity and peripheral tissue-specific metabolic alterations, such as an increase in gastrointestinal lipid absorption and hepatic cholesterol turnover. Finally, we show that intermittent fasting coupled with food-odor stimulation improves glycemic control and prevents insulin resistance in diet-induced obese mice. Thus, olfactory regulation is required for maintaining metabolic homeostasis in environments with either an energy deficit or energy surplus, which could be considered as part of dietary interventions against metabolic disorders.
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Affiliation(s)
- Hiroshi Tsuneki
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan.
| | - Masanori Sugiyama
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Toshihiro Ito
- Laboratory of Proteome Research, National Institutes of Biomedical Innovation, Health, and Nutrition, Osaka, Japan
| | - Kiyofumi Sato
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Hiroki Matsuda
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Kengo Onishi
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Koharu Yubune
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Yukina Matsuoka
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Sanaka Nagai
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Towa Yamagishi
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Takahiro Maeda
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Kosuke Honda
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Akira Okekawa
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Shiro Watanabe
- Division of Nutritional Biochemistry, University of Toyama, Toyama, Japan
| | - Keisuke Yaku
- Department of Molecular and Medical Pharmacology, University of Toyama, Toyama, Japan
| | - Daisuke Okuzaki
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Ryota Otsubo
- Laboratory of Infectious Diseases and Immunity, National Institutes of Biomedical Innovation, Health, and Nutrition, Osaka, Japan
- Laboratory of Immunobiologics Evaluation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health, and Nutrition, Osaka, Japan
| | - Masanori Nomoto
- Department of Biochemistry, University of Toyama, Toyama, Japan
- Research Centre for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Kaoru Inokuchi
- Department of Biochemistry, University of Toyama, Toyama, Japan
- Research Centre for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Takashi Nakagawa
- Department of Molecular and Medical Pharmacology, University of Toyama, Toyama, Japan
| | - Tsutomu Wada
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan
| | - Teruhito Yasui
- Laboratory of Infectious Diseases and Immunity, National Institutes of Biomedical Innovation, Health, and Nutrition, Osaka, Japan.
- Laboratory of Immunobiologics Evaluation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health, and Nutrition, Osaka, Japan.
- Laboratory of Pharmaceutical Integrated Omics, Department of Pharmaceutical Engineering, Facility of Engineering, Toyama Prefectural University, Toyama, Japan.
| | - Toshiyasu Sasaoka
- Department of Clinical Pharmacology, University of Toyama, Toyama, Japan.
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11
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Sarkar S. Microglial ion channels: Key players in non-cell autonomous neurodegeneration. Neurobiol Dis 2022; 174:105861. [PMID: 36115552 PMCID: PMC9617777 DOI: 10.1016/j.nbd.2022.105861] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/26/2022] [Accepted: 09/12/2022] [Indexed: 12/03/2022] Open
Abstract
Neuroinflammation is a critical pathophysiological hallmark of neurodegenerative disorders, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and traumatic brain injury (TBI). Microglia, the first responders of the brain, are the drivers of this neuroinflammation. Microglial activation, leading to induction of pro-inflammatory factors, like Interleukin 1-β (IL-1β), Tumor necrosis factor-α (TNFα), nitrites, and others, have been shown to induce neurodegeneration. Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce the risk of developing PD, but the mechanism underlying the microglial activation is still under active research. Recently, microglial ion channels have come to the forefront as potential drug targets in multiple neurodegenerative disorders, including AD and PD. Microglia expresses a variety of ion channels, including potassium channels, calcium channels, chloride channels, sodium channels, and proton channels. The diversity of channels present on microglia is responsible for the dynamic nature of these immune cells of the brain. These ion channels regulate microglial proliferation, chemotaxis, phagocytosis, antigen recognition and presentation, apoptosis, and cell signaling leading to inflammation, among other critical functions. Understanding the role of these ion channels and the signaling mechanism these channels regulate under pathological conditions is an active area of research. This review will be focusing on the roles of different microglial ion channels, and their potential role in regulating microglial functions in neurodegenerative disorders.
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Affiliation(s)
- Souvarish Sarkar
- Dept. of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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12
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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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13
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Wright JR, Jones S, Parvathy S, Kaczmarek LK, Forsythe I, Farndale RW, Gibbins JM, Mahaut-Smith MP. The voltage-gated K + channel Kv1.3 modulates platelet motility and α 2β 1 integrin-dependent adhesion to collagen. Platelets 2022; 33:451-461. [PMID: 34348571 PMCID: PMC8935947 DOI: 10.1080/09537104.2021.1942818] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/03/2021] [Accepted: 06/03/2021] [Indexed: 12/13/2022]
Abstract
Kv1.3 is a voltage-gated K+-selective channel with roles in immunity, insulin-sensitivity, neuronal excitability and olfaction. Despite being one of the largest ionic conductances of the platelet surface membrane, its contribution to platelet function is poorly understood. Here we show that Kv1.3-deficient platelets display enhanced ADP-evoked platelet aggregation and secretion, and an increased surface expression of platelet integrin αIIb. In contrast, platelet adhesion and thrombus formation in vitro under arterial shear conditions on surfaces coated with collagen were reduced for samples from Kv1.3-/- compared to wild type mice. Use of collagen-mimetic peptides revealed a specific defect in the engagement with α2β1. Kv1.3-/- platelets developed significantly fewer, and shorter, filopodia than wild type platelets during adhesion to collagen fibrils. Kv1.3-/- mice displayed no significant difference in thrombus formation within cremaster muscle arterioles using a laser-induced injury model, thus other pro-thrombotic pathways compensate in vivo for the adhesion defect observed in vitro. This may include the increased platelet counts of Kv1.3-/- mice, due in part to a prolonged lifespan. The ability of Kv1.3 to modulate integrin-dependent platelet adhesion has important implications for understanding its contribution to normal physiological platelet function in addition to its reported roles in auto-immune diseases and thromboinflammatory models of stroke.
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Affiliation(s)
- Joy R Wright
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Sarah Jones
- Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- Department of Life Sciences, Manchester Metropolitan University, Manchester, UK
| | - Sasikumar Parvathy
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK
| | - Leonard K Kaczmarek
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, USA
| | - Ian Forsythe
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | | | - Jonathan M Gibbins
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK
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14
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Jovanovic P, Riera CE. Olfactory system and energy metabolism: a two-way street. Trends Endocrinol Metab 2022; 33:281-291. [PMID: 35177346 DOI: 10.1016/j.tem.2022.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/11/2022] [Accepted: 01/16/2022] [Indexed: 12/31/2022]
Abstract
Olfactory perception guides daily decisions regarding food consumption, social interactions, and predator avoidance in all mammalian species. Volatile inputs, comprising odorants and pheromones, are relayed to the olfactory bulb (OB) from nasal sensory neurons cells and transferred to secondary processing regions within the brain. Olfaction has recently been shown to shape homeostatic and maladaptive processes of energy intake and expenditure through neuronal circuits involving the medial basal hypothalamus. Reciprocally, gastrointestinal hormones, such as ghrelin and leptin, the secretion of which depends on satiety and adiposity levels, might also influence olfactory sensitivity to alter food-seeking behaviors. Here, in addition to reviewing recent updates on identifying these neuronal networks, we also discuss how bidirectional neurocircuits existing between olfactory and energy processing centers can become dysregulated during obesity.
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Affiliation(s)
- Predrag Jovanovic
- Center for Neural Science and Medicine, Biomedical Sciences Department and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 127 South San Vicente Boulevard, Los Angeles, CA 90048, USA
| | - Celine E Riera
- Center for Neural Science and Medicine, Biomedical Sciences Department and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 127 South San Vicente Boulevard, Los Angeles, CA 90048, USA; Department of Neurology, Cedars-Sinai Medical Center, Movement Disorder Program, 127 South San Vicente Boulevard, Los Angeles, CA 90048, USA; David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
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15
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Zucco GM, Doty RL. Multiple Chemical Sensitivity. Brain Sci 2021; 12:46. [PMID: 35053790 PMCID: PMC8773480 DOI: 10.3390/brainsci12010046] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 01/09/2023] Open
Abstract
Multiple Chemical Sensitivity (MCS), a condition also known as Chemical Sensitivity (CS), Chemical Intolerance (CI), Idiopathic Environmental Illness (IEI) and Toxicant Induced Loss of Tolerance (TILT), is an acquired multifactorial syndrome characterized by a recurrent set of debilitating symptoms. The symptoms of this controversial disorder are reported to be induced by environmental chemicals at doses far below those usually harmful to most persons. They involve a large spectrum of organ systems and typically disappear when the environmental chemicals are removed. However, no clear link has emerged among self-reported MCS symptoms and widely accepted objective measures of physiological dysfunction, and no clear dose-response relationship between exposure and symptom reactions has been observed. In addition, the underlying etiology and pathogenic processes of the disorder remain unknown and disputed, although biologic and psychologic hypotheses abound. It is currently debated whether MCS should be considered a clinical entity at all. Nevertheless, in the last few decades MCS has received considerable scientific and governmental attention in light of the many persons reporting this illness. In this review, we provide a general overview of the history, definition, demographics, prevalence, and etiologic challenges in defining and understanding MCS.
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Affiliation(s)
- Gesualdo M Zucco
- Department of Philosophy, Sociology, Education and Applied Psychology, University of Padova, 35100 Padova, Italy
| | - Richard L Doty
- Smell and Taste Center, Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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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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17
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Cocozza G, Garofalo S, Capitani R, D’Alessandro G, Limatola C. Microglial Potassium Channels: From Homeostasis to Neurodegeneration. Biomolecules 2021; 11:1774. [PMID: 34944418 PMCID: PMC8698630 DOI: 10.3390/biom11121774] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/21/2022] Open
Abstract
The growing interest in the role of microglia in the progression of many neurodegenerative diseases is developing in an ever-expedited manner, in part thanks to emergent new tools for studying the morphological and functional features of the CNS. The discovery of specific biomarkers of the microglia phenotype could find application in a wide range of human diseases, and creates opportunities for the discovery and development of tailored therapeutic interventions. Among these, recent studies highlight the pivotal role of the potassium channels in regulating microglial functions in physiological and pathological conditions such as Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis. In this review, we summarize the current knowledge of the involvement of the microglial potassium channels in several neurodegenerative diseases and their role as modulators of microglial homeostasis and dysfunction in CNS disorders.
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Affiliation(s)
- Germana Cocozza
- Instituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, 86077 Pozzilli, Italy; (G.C.); (G.D.)
| | - Stefano Garofalo
- Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Rome, Italy; (S.G.); (R.C.)
| | - Riccardo Capitani
- Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Rome, Italy; (S.G.); (R.C.)
| | - Giuseppina D’Alessandro
- Instituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, 86077 Pozzilli, Italy; (G.C.); (G.D.)
- Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Rome, Italy; (S.G.); (R.C.)
| | - Cristina Limatola
- Instituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, 86077 Pozzilli, Italy; (G.C.); (G.D.)
- Department of Physiology and Pharmacology, Laboratory Affiliated to Istituto Pasteur Italia, Sapienza University of Rome, 00185 Rome, Italy
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18
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Chelette BM, Loeven AM, Gatlin DN, Landi Conde DR, Huffstetler CM, Qi M, Fadool DA. Consumption of dietary fat causes loss of olfactory sensory neurons and associated circuitry that is not mitigated by voluntary exercise in mice. J Physiol 2021; 600:1473-1495. [PMID: 34807463 PMCID: PMC10102708 DOI: 10.1113/jp282112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/05/2021] [Indexed: 12/12/2022] Open
Abstract
Excess nutrition causes loss of olfactory sensory neurons (OSNs) and reduces odour discrimination and odour perception in mice. To separate diet-induced obesity from the consumption of dietary fat, we designed pair-feeding experiments whereby mice were maintained on isocaloric diets for 5 months, which prevented increased fat storage. To test our hypothesis that adiposity was not a prerequisite for loss of OSNs and bulbar projections, we used male and female mice with an odorant receptor-linked genetic reporter (M72tauLacZ; Olfr160) to visualize neural circuitry changes resulting from elevated fat in the diet. Simultaneously we monitored glucose clearance (diagnostic for prediabetes), body fat deposition, ingestive behaviours, select inflammatory markers and energy metabolism. Axonal projections to defined olfactory glomeruli were visualized in whole-mount brains, and the number of OSNs was manually counted across whole olfactory epithelia. After being pair fed a moderately high-fat (MHF) diet, mice of both sexes had body weight, adipose deposits, energy expenditure, respiratory exchange ratios and locomotor activity that were unchanged from control-fed mice. Despite this, they were still found to lose OSNs and associated bulbar projections. Even with unchanged adipocyte storage, pair-fed animals had an elevation in TNF cytokines and an intermediate ability for glucose clearance. Albeit improving health metrics, access to voluntary running while consuming an ad libitum fatty diet still precipitated a loss of OSNs and associated axonal projections for male mice. Our results support that long-term macronutrient imbalance can drive anatomical loss in the olfactory system regardless of total energy expenditure. KEY POINTS: Obesity can disrupt the structure and function of organ systems, including the olfactory system that is important for food selection and satiety. We designed dietary treatments in mice such that mice received fat, but the total calories provided were the same as in control diets so that they would not gain weight or increase adipose tissue. Mice that were not obese but consumed isocaloric fatty diets still lost olfactory neuronal circuits, had fewer numbers of olfactory neurons, had an elevation in inflammatory signals and had an intermediate ability to clear glucose (prediabetes). Mice were allowed access to running wheels while consuming fatty diets, yet still lost olfactory structures. We conclude that a long-term imbalance in nutrition that favours fat in the diet disrupts the olfactory system of mice in the absence of obesity.
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Affiliation(s)
- Brandon M Chelette
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Programs in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Ashley M Loeven
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Destinee N Gatlin
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Programs in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Daniel R Landi Conde
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Programs in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Carley M Huffstetler
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Meizhu Qi
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Programs in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Debra Ann Fadool
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Programs in Neuroscience, Florida State University, Tallahassee, FL, USA.,Molecular Biophysics, Florida State University, Tallahassee, FL, USA
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19
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Causton HC. SARS-CoV2 Infection and the Importance of Potassium Balance. Front Med (Lausanne) 2021; 8:744697. [PMID: 34778307 PMCID: PMC8578622 DOI: 10.3389/fmed.2021.744697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/30/2021] [Indexed: 01/05/2023] Open
Abstract
SARS-CoV2 infection results in a range of symptoms from mild pneumonia to cardiac arrhythmias, hyperactivation of the immune response, systemic organ failure and death. However, the mechanism of action has been hard to establish. Analysis of symptoms associated with COVID-19, the activity of repurposed drugs associated with lower death rates or antiviral activity in vitro and a small number of studies describing interventions, point to the importance of electrolyte, and particularly potassium, homeostasis at both the cellular, and systemic level. Elevated urinary loss of potassium is associated with disease severity, and the response to electrolyte replenishment correlates with progression toward recovery. These findings suggest possible diagnostic opportunities and therapeutic interventions. They provide insights into comorbidities and mechanisms associated with infection by SARS-CoV2 and other RNA viruses that target the ACE2 receptor, and/or activate cytokine-mediated immune responses in a potassium-dependent manner.
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Affiliation(s)
- Helen C Causton
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, United States
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20
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Martelli C, Storace DA. Stimulus Driven Functional Transformations in the Early Olfactory System. Front Cell Neurosci 2021; 15:684742. [PMID: 34413724 PMCID: PMC8369031 DOI: 10.3389/fncel.2021.684742] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/06/2021] [Indexed: 11/17/2022] Open
Abstract
Olfactory stimuli are encountered across a wide range of odor concentrations in natural environments. Defining the neural computations that support concentration invariant odor perception, odor discrimination, and odor-background segmentation across a wide range of stimulus intensities remains an open question in the field. In principle, adaptation could allow the olfactory system to adjust sensory representations to the current stimulus conditions, a well-known process in other sensory systems. However, surprisingly little is known about how adaptation changes olfactory representations and affects perception. Here we review the current understanding of how adaptation impacts processing in the first two stages of the vertebrate olfactory system, olfactory receptor neurons (ORNs), and mitral/tufted cells.
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Affiliation(s)
- Carlotta Martelli
- Institute of Developmental Biology and Neurobiology, University of Mainz, Mainz, Germany
| | - Douglas Anthony Storace
- Department of Biological Science, Florida State University, Tallahassee, FL, United States
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States
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21
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Light-regulated voltage-gated potassium channels for acute interrogation of channel function in neurons and behavior. PLoS One 2021; 16:e0248688. [PMID: 33755670 PMCID: PMC7987177 DOI: 10.1371/journal.pone.0248688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 03/03/2021] [Indexed: 01/02/2023] Open
Abstract
Voltage-gated potassium (Kv) channels regulate the membrane potential and conductance of excitable cells to control the firing rate and waveform of action potentials. Even though Kv channels have been intensely studied for over 70 year, surprisingly little is known about how specific channels expressed in various neurons and their functional properties impact neuronal network activity and behavior in vivo. Although many in vivo genetic manipulations of ion channels have been tried, interpretation of these results is complicated by powerful homeostatic plasticity mechanisms that act to maintain function following perturbations in excitability. To better understand how Kv channels shape network function and behavior, we have developed a novel optogenetic technology to acutely regulate Kv channel expression with light by fusing the light-sensitive LOV domain of Vaucheria frigida Aureochrome 1 to the N-terminus of the Kv1 subunit protein to make an Opto-Kv1 channel. Recording of Opto-Kv1 channels expressed in Xenopus oocytes, mammalian cells, and neurons show that blue light strongly induces the current expression of Opto-Kv1 channels in all systems tested. We also find that an Opto-Kv1 construct containing a dominant-negative pore mutation (Opto-Kv1(V400D)) can be used to down-regulate Kv1 currents in a blue light-dependent manner. Finally, to determine whether Opto-Kv1 channels can elicit light-dependent behavioral effect in vivo, we targeted Opto-Kv1 (V400D) expression to Kv1.3-expressing mitral cells of the olfactory bulb in mice. Exposure of the bulb to blue light for 2–3 hours produced a significant increase in sensitivity to novel odors after initial habituation to a similar odor, comparable to behavioral changes seen in Kv1.3 knockout animals. In summary, we have developed novel photoactivatable Kv channels that provide new ways to interrogate neural circuits in vivo and to examine the roles of normal and disease-causing mutant Kv channels in brain function and behavior.
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22
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Noterman MF, Chaubey K, Lin-Rahardja K, Rajadhyaksha AM, Pieper AA, Taylor EB. Dual-process brain mitochondria isolation preserves function and clarifies protein composition. Proc Natl Acad Sci U S A 2021; 118:e2019046118. [PMID: 33836587 PMCID: PMC7980376 DOI: 10.1073/pnas.2019046118] [Citation(s) in RCA: 3] [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] [Indexed: 12/12/2022] Open
Abstract
The brain requires continuously high energy production to maintain ion gradients and normal function. Mitochondria critically undergird brain energetics, and mitochondrial abnormalities feature prominently in neuropsychiatric disease. However, many unique aspects of brain mitochondria composition and function are poorly understood. Developing improved neuroprotective therapeutics thus requires more comprehensively understanding brain mitochondria, including accurately delineating protein composition and channel-transporter functional networks. However, obtaining pure mitochondria from the brain is especially challenging due to its distinctive lipid and cell structure properties. As a result, conflicting reports on protein localization to brain mitochondria abound. Here we illustrate this problem with the neuropsychiatric disease-associated L-type calcium channel Cav1.2α1 subunit previously observed in crude mitochondria. We applied a dual-process approach to obtain functionally intact versus compositionally pure brain mitochondria. One branch utilizes discontinuous density gradient centrifugation to isolate semipure mitochondria suitable for functional assays but unsuitable for protein localization because of endoplasmic reticulum (ER) contamination. The other branch utilizes self-forming density gradient ultracentrifugation to remove ER and yield ultrapure mitochondria that are suitable for investigating protein localization but functionally compromised. Through this process, we evaluated brain mitochondria protein content and observed the absence of Cav1.2α1 and other previously reported mitochondrial proteins, including the NMDA receptor, ryanodine receptor 1, monocarboxylate transporter 1, excitatory amino acid transporter 1, and glyceraldehyde 3-phosphate dehydrogenase. Conversely, we confirmed mitochondrial localization of several plasma membrane proteins previously reported to also localize to mitochondria. We expect this dual-process isolation procedure will enhance understanding of brain mitochondria in both health and disease.
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Affiliation(s)
- Maria F Noterman
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242
| | - Kalyani Chaubey
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH 44106
- Department of Psychiatry, Case Western Reserve University, Cleveland, OH 44106
| | - Kristi Lin-Rahardja
- Department of Systems Biology and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106
| | - Anjali M Rajadhyaksha
- Weill Cornell Autism Research Program, Weill Cornell Medicine of Cornell University, New York, NY 10065
- Pediatric Neurology, Pediatrics, Weill Cornell Medicine of Cornell University, New York, NY 10065
| | - Andrew A Pieper
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH 44106;
- Department of Psychiatry, Case Western Reserve University, Cleveland, OH 44106
- Weill Cornell Autism Research Program, Weill Cornell Medicine of Cornell University, New York, NY 10065
- Geriatric Research Education and Clinical Centers, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106
- Department of Neuroscience, School of Medicine, Case Western Reserve University, Cleveland, OH 44106
| | - Eric B Taylor
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242;
- Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA 52242
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242
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23
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Honmou O, Yamashita T, Morita T, Oshigiri T, Hirota R, Iyama S, Kato J, Sasaki Y, Ishiai S, Ito YM, Namioka A, Namioka T, Nakazaki M, Kataoka-Sasaki Y, Onodera R, Oka S, Sasaki M, Waxman SG, Kocsis JD. Intravenous infusion of auto serum-expanded autologous mesenchymal stem cells in spinal cord injury patients: 13 case series. Clin Neurol Neurosurg 2021; 203:106565. [PMID: 33667953 DOI: 10.1016/j.clineuro.2021.106565] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 11/12/2020] [Accepted: 02/16/2021] [Indexed: 01/24/2023]
Abstract
BACKGROUND Although spinal cord injury (SCI) is a major cause of disability, current therapeutic options remain limited. Recent progress in cellular therapy with mesenchymal stem cells (MSCs) has provided improved function in animal models of SCI. We investigated the safety and feasibility of intravenous infusion of MSCs for SCI patients and assessed functional status after MSC infusion. METHODS In this phase 2 study of intravenous infusion of autologous MSCs cultured in auto-serum, a single infusion of MSCs under Good Manufacturing Practice (GMP) production was delivered in 13 SCI patients. In addition to assessing feasibility and safety, neurological function was assessed using the American Spinal Injury Association Impairment Scale (ASIA), International Standards for Neurological and Functional Classification of Spinal Cord (ISCSCI-92). Ability of daily living was assessed using Spinal Cord Independence Measure (SCIM-III). The study protocol was based on advice provided by the Pharmaceuticals and Medical Devices Agency in Japan. The trial was registered with the Japan Medical Association (JMA-IIA00154). RESULTS No serious adverse events were associated with MSC injection. There was neurologic improvement based on ASIA grade in 12 of the 13 patients at six months post-MSC infusion. Five of six patients classified as ASIA A prior to MSC infusion improved to ASIA B (3/6) or ASIA C (2/6), two ASIA B patients improved to ASIA C (1/2) or ASIA D (1/2), five ASIA C patients improved and reached a functional status of ASIA D (5/5). Notably, improvement from ASIA C to ASIA D was observed one day following MSC infusion for all five patients. Assessment of both ISCSCI-92, SCIM-III also demonstrated functional improvements at six months after MSC infusion, compared to the scores prior to MSC infusion in all patients. CONCLUSION While we emphasize that this study was unblinded, and does not exclude placebo effects or a contribution of endogenous recovery or observer bias, our observations provide evidence supporting the feasibility, safety and functional improvements of infused MSCs into patients with SCI.
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Affiliation(s)
- Osamu Honmou
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Advanced Regenerative Therapeutics, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Toshihiko Yamashita
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Tomonori Morita
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Tsutomu Oshigiri
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Ryosuke Hirota
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Satoshi Iyama
- Department of Hematology, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Junji Kato
- Department of Medical Oncology, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Yuichi Sasaki
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Rehabilitation, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Sumio Ishiai
- Department of Rehabilitation, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Yoichi M Ito
- Biostatistics Division, Hokkaido University Hospital Clinical Research and Medical Innovation Center, Sapporo, Hokkaido, 060-8648, Japan
| | - Ai Namioka
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Takahiro Namioka
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Masahito Nakazaki
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Yuko Kataoka-Sasaki
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Advanced Regenerative Therapeutics, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Rie Onodera
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Shinichi Oka
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Advanced Regenerative Therapeutics, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan
| | - Masanori Sasaki
- Department of Neural Regenerative Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Advanced Regenerative Therapeutics, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Hokkaido, Japan; Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA.
| | - Stephen G Waxman
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Jeffery D Kocsis
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06510, USA
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24
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Sarkar S, Nguyen HM, Malovic E, Luo J, Langley M, Palanisamy BN, Singh N, Manne S, Neal M, Gabrielle M, Abdalla A, Anantharam P, Rokad D, Panicker N, Singh V, Ay M, Charli A, Harischandra D, Jin LW, Jin H, Rangaraju S, Anantharam V, Wulff H, Kanthasamy AG. Kv1.3 modulates neuroinflammation and neurodegeneration in Parkinson's disease. J Clin Invest 2021; 130:4195-4212. [PMID: 32597830 DOI: 10.1172/jci136174] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Characterization of the key cellular targets contributing to sustained microglial activation in neurodegenerative diseases, including Parkinson's disease (PD), and optimal modulation of these targets can provide potential treatments to halt disease progression. Here, we demonstrated that microglial Kv1.3, a voltage-gated potassium channel, was transcriptionally upregulated in response to aggregated α-synuclein (αSynAgg) stimulation in primary microglial cultures and animal models of PD, as well as in postmortem human PD brains. Patch-clamp electrophysiological studies confirmed that the observed Kv1.3 upregulation translated to increased Kv1.3 channel activity. The kinase Fyn, a risk factor for PD, modulated transcriptional upregulation and posttranslational modification of microglial Kv1.3. Multiple state-of-the-art analyses, including Duolink proximity ligation assay imaging, revealed that Fyn directly bound to Kv1.3 and posttranslationally modified its channel activity. Furthermore, we demonstrated the functional relevance of Kv1.3 in augmenting the neuroinflammatory response by using Kv1.3-KO primary microglia and the Kv1.3-specific small-molecule inhibitor PAP-1, thus highlighting the importance of Kv1.3 in neuroinflammation. Administration of PAP-1 significantly inhibited neurodegeneration and neuroinflammation in multiple animal models of PD. Collectively, our results imply that Fyn-dependent regulation of Kv1.3 channels plays an obligatory role in accentuating the neuroinflammatory response in PD and identify Kv1.3 as a potential therapeutic target for PD.
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Affiliation(s)
- Souvarish Sarkar
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Hai M Nguyen
- Department of Pharmacology, School of Medicine, UCD, Davis, California, USA
| | - Emir Malovic
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Jie Luo
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Monica Langley
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Bharathi N Palanisamy
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Neeraj Singh
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Sireesha Manne
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Matthew Neal
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Michelle Gabrielle
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Ahmed Abdalla
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Poojya Anantharam
- Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Medicine Building, ISU, Ames, Iowa, USA
| | - Dharmin Rokad
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Nikhil Panicker
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Vikrant Singh
- Department of Pharmacology, School of Medicine, UCD, Davis, California, USA
| | - Muhammet Ay
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Adhithiya Charli
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Dilshan Harischandra
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Lee-Way Jin
- M.I.N.D. Institute, Alzheimer's Disease Center, Department of Pathology and Laboratory Medicine, UCD, Davis, California, USA
| | - Huajun Jin
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Srikant Rangaraju
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Vellareddy Anantharam
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
| | - Heike Wulff
- Department of Pharmacology, School of Medicine, UCD, Davis, California, USA
| | - Anumantha G Kanthasamy
- Parkinson Disorders Research Laboratory, Department of Biomedical Sciences, Iowa State University (ISU), Ames, Iowa, USA
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25
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Timely Inhibitory Circuit Formation Controlled by Abl1 Regulates Innate Olfactory Behaviors in Mouse. Cell Rep 2021; 30:187-201.e4. [PMID: 31914386 DOI: 10.1016/j.celrep.2019.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 10/16/2019] [Accepted: 11/27/2019] [Indexed: 12/15/2022] Open
Abstract
More than one-half of the interneurons in a mouse olfactory bulb (OB) develop during the first week after birth and predominantly connect to excitatory tufted cells near the superficial granule cell layer (sGCL), unlike late-born interneurons. However, the molecular mechanisms underlying the temporal specification are yet to be identified. In this study, we determined the role of Abelson tyrosine-protein kinase 1 (Abl1) in the temporal development of early-born OB interneurons. Lentiviral knockdown of Abl1 disrupts the sGCL circuit of early-born interneurons through defects in function and circuit integration, resulting in olfactory hyper-sensitivity. We show that doublecortin (Dcx) is phosphorylated by Abl1, which contributes to the stabilization of Dcx, thereby regulating microtubule dynamics. Finally, Dcx overexpression rescues Abl1 knockdown-induced anatomic or functional defects. In summary, specific signaling by Abl1-Dcx in early-born interneurons facilitates the temporal development of the sGCL circuit to regulate innate olfactory functions, such as detection and sensitivity.
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26
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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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27
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Fan C, Yang X, Wang WW, Wang J, Li W, Guo M, Huang S, Wang Z, Liu K. Role of Kv1.3 Channels in Platelet Functions and Thrombus Formation. Arterioscler Thromb Vasc Biol 2020; 40:2360-2375. [PMID: 32787516 DOI: 10.1161/atvbaha.120.314278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective:
Platelet activation by stimulatory factors leads to an increase in intracellular calcium concentration ([Ca
2+
]
i
), which is essential for almost all platelet functions. Modulation of Ca
2+
influx and [Ca
2+
]
i
in platelets has been emerging as a possible strategy for preventing and treating platelet-dependent thrombosis. Voltage-gated potassium 1.3 channels (Kv1.3) are highly expressed in platelets and able to regulate agonist-evoked [Ca
2+
]
i
increase. However, the role of Kv1.3 channels in regulating platelet functions and thrombosis has not yet been elucidated. In addition, it is difficult to obtain a specific blocker for this channel, since Kv1.3 shares identical drug-binding sites with other K
+
channels. Here, we investigate whether specific blockade of Kv1.3 channels by monoclonal antibodies affects platelet functions and thrombosis.
Approach and Results:
In this study, we produced the anti-Kv1.3 monoclonal antibody 6E12#15, which could specifically recognize both human and mouse Kv1.3 proteins and sufficiently block Kv1.3 channel currents. We found Kv1.3 blockade by 6E12#15 inhibited platelet aggregation, adhesion, and activation upon agonist stimulation. In vivo treatment with 6E12#15 alleviated thrombus formation in a mesenteric arteriole thrombosis mouse model and protected mice from collagen/epinephrine-induced pulmonary thromboembolism. Furthermore, we observed Kv1.3 regulated platelet functions by modulating Ca
2+
influx and [Ca
2+
]
i
elevation, and that this is mediated in part by P2X
1
. Interestingly,
Kv1.3
−/−
mice showed impaired platelet aggregation while displayed no abnormalities in in vivo thrombus formation. This phenomenon was related to more megakaryocytes and platelets produced in
Kv1.3
−/−
mice compared with wild-type mice.
Conclusions:
We showed specific inhibition of Kv1.3 by the novel monoclonal antibody 6E12#15 suppressed platelet functions and platelet-dependent thrombosis through modulating platelet [Ca
2+
]
i
elevation. These results indicate that Kv1.3 could act as a promising therapeutic target for antiplatelet therapies.
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Affiliation(s)
- Cheng Fan
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (C.F., M.G., S.H., Z.W.)
| | - Xiaofang Yang
- Center for Cardiac Intensive Care, Beijing Anzhen Hospital, Capital Medical University, China (X.Y.)
| | | | - Jue Wang
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (J.W.)
| | - Wenzhu Li
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (W.L.)
| | - Mengyuan Guo
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (C.F., M.G., S.H., Z.W.)
| | - Shiyuan Huang
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (C.F., M.G., S.H., Z.W.)
| | - Zhaohui Wang
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (C.F., M.G., S.H., Z.W.)
| | - Kun Liu
- Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (K.L.)
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28
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Chelette BM, Thomas AM, Fadool DA. Long-term obesogenic diet and targeted deletion of potassium channel K v 1.3 have differing effects on voluntary exercise in mice. Physiol Rep 2020; 7:e14254. [PMID: 31646751 PMCID: PMC6811687 DOI: 10.14814/phy2.14254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 09/03/2019] [Indexed: 12/27/2022] Open
Abstract
Voluntary exercise is frequently employed as an intervention for obesity. The voltage‐gated potassium channel Kv1.3 is also receiving attention as a therapeutic target for obesity, in addition to potential therapeutic capabilities for neuroinflammatory diseases. To investigate the combinatorial effects of these two therapies, we have compared the metabolic status and voluntary exercise behavior of both wild‐type mice and a transgenic line of mice that are genetic knockouts for Kv1.3 when provided with a running wheel and maintained on diets of differing fat content and caloric density. We tracked the metabolic parameters and wheel running behavior while maintaining the mice on their assigned treatment for 6 months. Wild‐type mice maintained on the fatty diet gain a significant amount of bodyweight and adipose tissue and display significantly impaired glucose tolerance, though all these effects were partially reduced with provision of a running wheel. Similar to previous studies, the Kv1.3‐null mice were resistant to obesity, increased adiposity, and impaired glucose tolerance. Both wild‐type and Kv1.3‐null mice maintained on the fatty diet displayed increased wheel running activity compared to control‐fed mice, which was caused primarily by a significant increase in the amount of time spent running as opposed to an increase in running velocity. Interestingly, the patterns of running behavior differed between wild‐type and Kv1.3‐null mice. Kv1.3‐null mice spent significantly less time running during the light phase and displayed a decrease in running 1–2 h before the onset of the light phase, seemingly in anticipation of the dark‐to‐light phase transition. These studies indicate that voluntary exercise combats metabolic maladies and running behavior is modified by both consumption of an obesogenic diet and deletion of the Kv1.3 channel.
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Affiliation(s)
- Brandon M Chelette
- Department of Biological Science, The Florida State University, Tallahassee, Florida.,Programs in Neuroscience, The Florida State University, Tallahassee, Florida
| | - Abigail M Thomas
- Department of Biological Science, The Florida State University, Tallahassee, Florida
| | - Debra Ann Fadool
- Department of Biological Science, The Florida State University, Tallahassee, Florida.,Programs in Neuroscience, The Florida State University, Tallahassee, Florida.,Molecular Biophysics, The Florida State University, Tallahassee, Florida
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29
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Tajti G, Wai DCC, Panyi G, Norton RS. The voltage-gated potassium channel K V1.3 as a therapeutic target for venom-derived peptides. Biochem Pharmacol 2020; 181:114146. [PMID: 32653588 DOI: 10.1016/j.bcp.2020.114146] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 02/07/2023]
Abstract
The voltage-gated potassium channel KV1.3 is a well-established therapeutic target for a range of autoimmune diseases, in addition to being the site of action of many venom-derived peptides. Numerous studies have documented the efficacy of venom peptides that target KV1.3, in particular from sea anemones and scorpions, in animal models of autoimmune diseases such as rheumatoid arthritis, psoriasis and multiple sclerosis. Moreover, an analogue of the sea anemone peptide ShK (known as dalazatide) has successfully completed Phase 1 clinical trials in mild-to-moderate plaque psoriasis. In this article we consider other potential therapeutic applications of inhibitors of KV1.3, including in inflammatory bowel disease and neuroinflammatory conditions such as Alzheimer's and Parkinson's diseases, as well as fibrotic diseases. We also summarise strategies for facilitating the entry of peptides to the central nervous system, given that this will be a pre-requisite for the treatment of most neuroinflammatory diseases. Venom-derived peptides that have been reported recently to target KV1.3 are also described. The increasing number of autoimmune and other conditions in which KV1.3 is upregulated and is therefore a potential therapeutic target, combined with the fact that many venom-derived peptides are potent inhibitors of KV1.3, suggests that venoms are likely to continue to serve as a rich source of new pharmacological tools and therapeutic leads targeting this channel.
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Affiliation(s)
- Gabor Tajti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Dorothy C C Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, VIC 3052, Australia.
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30
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Blocking Kv1.3 potassium channels prevents postoperative neuroinflammation and cognitive decline without impairing wound healing in mice. Br J Anaesth 2020; 125:298-307. [PMID: 32624183 DOI: 10.1016/j.bja.2020.05.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/15/2020] [Accepted: 05/06/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Postoperative cognitive decline (PCD) requires microglial activation. Voltage-gated Kv1.3 potassium channels are involved in microglial activation. We determined the role of Kv1.3 in PCD and the efficacy and safety of inhibiting Kv1.3 with phenoxyalkoxypsoralen-1 (PAP-1) in preventing PCD in a mouse model. METHODS After institutional approval, we assessed whether Kv1.3-deficient mice (Kv1.3-/-) exhibited PCD, evidenced by tibial-fracture surgery-induced decline in aversive freezing behaviour, and whether PAP-1 could prevent PCD and postoperative neuroinflammation in PCD-vulnerable diet-induced obese (DIO) mice. We also evaluated whether PAP-1 altered either postoperative peripheral inflammation or tibial-fracture healing. RESULTS Freezing behaviour was unaltered in postoperative Kv1.3-/- mice. In DIO mice, PAP-1 prevented postoperative (i) attenuation of freezing behaviour (54 [17.3]% vs 33.4 [12.7]%; P=0.03), (ii) hippocampal microglial activation by size (130 [31] pixels vs 249 [49]; P<0.001) and fluorescence intensity (12 000 [2260] vs 20 800 [5080] absorbance units; P<0.001), and (iii) hippocampal upregulation of interleukin-6 (IL-6) (14.9 [5.7] vs 25.6 [10.4] pg mg-1; P=0.011). Phenoxyalkoxypsoralen-1 neither affected surgery-induced upregulation of plasma IL-6 nor cartilage and bone components of the surgical fracture callus. CONCLUSIONS Microglial-mediated PCD requires Kv1.3 activity, determined by genetic and pharmacological targeting approaches. Phenoxyalkoxypsoralen-1 blockade of Kv1.3 prevented surgery-induced hippocampal microglial activation and neuroinflammation in mice known to be vulnerable to PCD. Regarding perioperative safety, these beneficial effects of PAP-1 treatment occurred without impacting fracture healing. Kv1.3 blockers, currently undergoing clinical trials for other conditions, may represent an effective and safe intervention to prevent PCD.
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31
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Mitf Links Neuronal Activity and Long-Term Homeostatic Intrinsic Plasticity. eNeuro 2020; 7:ENEURO.0412-19.2020. [PMID: 32193365 PMCID: PMC7174873 DOI: 10.1523/eneuro.0412-19.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 02/07/2020] [Accepted: 03/02/2020] [Indexed: 12/25/2022] Open
Abstract
Neuroplasticity forms the basis for neuronal circuit complexity and differences between otherwise similar circuits. We show that the microphthalmia-associated transcription factor (Mitf) plays a central role in intrinsic plasticity of olfactory bulb (OB) projection neurons. Mitral and tufted (M/T) neurons from Mitf mutant mice are hyperexcitable, have a reduced A-type potassium current (IA) and exhibit reduced expression of Kcnd3, which encodes a potassium voltage-gated channel subunit (Kv4.3) important for generating the IA Furthermore, expression of the Mitf and Kcnd3 genes is activity dependent in OB projection neurons and the MITF protein activates expression from Kcnd3 regulatory elements. Moreover, Mitf mutant mice have changes in olfactory habituation and have increased habituation for an odorant following long-term exposure, indicating that regulation of Kcnd3 is pivotal for long-term olfactory adaptation. Our findings show that Mitf acts as a direct regulator of intrinsic homeostatic feedback and links neuronal activity, transcriptional changes and neuronal function.
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32
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Serrano-Albarrás A, Cirera-Rocosa S, Sastre D, Estadella I, Felipe A. Fighting rheumatoid arthritis: Kv1.3 as a therapeutic target. Biochem Pharmacol 2019; 165:214-220. [DOI: 10.1016/j.bcp.2019.03.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/12/2019] [Indexed: 01/18/2023]
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33
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Maezawa I, Nguyen HM, Di Lucente J, Jenkins DP, Singh V, Hilt S, Kim K, Rangaraju S, Levey AI, Wulff H, Jin LW. Kv1.3 inhibition as a potential microglia-targeted therapy for Alzheimer's disease: preclinical proof of concept. Brain 2019; 141:596-612. [PMID: 29272333 DOI: 10.1093/brain/awx346] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/30/2017] [Indexed: 12/14/2022] Open
Abstract
Microglia significantly contribute to the pathophysiology of Alzheimer's disease but an effective microglia-targeted therapeutic approach is not yet available clinically. The potassium channels Kv1.3 and Kir2.1 play important roles in regulating immune cell functions and have been implicated by in vitro studies in the 'M1-like pro-inflammatory' or 'M2-like anti-inflammatory' state of microglia, respectively. We here found that amyloid-β oligomer-induced expression of Kv1.3 and Kir2.1 in cultured primary microglia. Likewise, ex vivo microglia acutely isolated from the Alzheimer's model 5xFAD mice co-expressed Kv1.3 and Kir2.1 as well as markers traditionally associated with M1 and M2 activation suggesting that amyloid-β oligomer induces a microglial activation state that is more complex than previously thought. Using the orally available, brain penetrant small molecule Kv1.3 blocker PAP-1 as a tool, we showed that pro-inflammatory and neurotoxic microglial responses induced by amyloid-β oligomer required Kv1.3 activity in vitro and in hippocampal slices. Since we further observed that Kv1.3 was highly expressed in microglia of transgenic Alzheimer's mouse models and human Alzheimer's disease brains, we hypothesized that pharmacological Kv1.3 inhibition could mitigate the pathology induced by amyloid-β aggregates. Indeed, treating APP/PS1 transgenic mice with a 5-month oral regimen of PAP-1, starting at 9 months of age, when the animals already manifest cognitive deficits and amyloid pathology, reduced neuroinflammation, decreased cerebral amyloid load, enhanced hippocampal neuronal plasticity, and improved behavioural deficits. The observed decrease in cerebral amyloid deposition was consistent with the in vitro finding that PAP-1 enhanced amyloid-β uptake by microglia. Collectively, these results provide proof-of-concept data to advance Kv1.3 blockers to Alzheimer's disease clinical trials.
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Affiliation(s)
- Izumi Maezawa
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, 2805 50th Street, Sacramento, CA 95817, USA
| | - Hai M Nguyen
- Department of Pharmacology, University of California Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Jacopo Di Lucente
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, 2805 50th Street, Sacramento, CA 95817, USA
| | - David Paul Jenkins
- Department of Pharmacology, University of California Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Vikrant Singh
- Department of Pharmacology, University of California Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Silvia Hilt
- Department of Biochemistry and Molecular Medicine, University of California Davis, 2700 Stockton Blvd, Sacramento, CA 95817, USA
| | - Kyoungmi Kim
- Department of Public Health Sciences, University of California Davis, One Shields Avenue, Med Sci 1-C, Davis, CA 95616, USA
| | - Srikant Rangaraju
- Department of Neurology and Alzheimer's Disease Research Center, Emory University, 201 Dowman Drive, Atlanta, GA 30322, USA
| | - Allan I Levey
- Department of Neurology and Alzheimer's Disease Research Center, Emory University, 201 Dowman Drive, Atlanta, GA 30322, USA
| | - Heike Wulff
- Department of Pharmacology, University of California Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, 2805 50th Street, Sacramento, CA 95817, USA.,Alzheimer's Disease Center, University of California Davis Medical Center, 4860 Y Street, Suite 3900, Sacramento, CA 95817, USA
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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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Al Koborssy D, Palouzier-Paulignan B, Canova V, Thevenet M, Fadool DA, Julliard AK. Modulation of olfactory-driven behavior by metabolic signals: role of the piriform cortex. Brain Struct Funct 2018; 224:315-336. [PMID: 30317390 DOI: 10.1007/s00429-018-1776-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/08/2018] [Indexed: 12/25/2022]
Abstract
Olfaction is one of the major sensory modalities that regulates food consumption and is in turn regulated by the feeding state. Given that the olfactory bulb has been shown to be a metabolic sensor, we explored whether the anterior piriform cortex (aPCtx)-a higher olfactory cortical processing area-had the same capacity. Using immunocytochemical approaches, we report the localization of Kv1.3 channel, glucose transporter type 4, and the insulin receptor in the lateral olfactory tract and Layers II and III of the aPCtx. In current-clamped superficial pyramidal (SP) cells, we report the presence of two populations of SP cells: glucose responsive and non-glucose responsive. Using varied glucose concentrations and a glycolysis inhibitor, we found that insulin modulation of the instantaneous and spike firing frequency are both glucose dependent and require glucose metabolism. Using a plethysmograph to record sniffing frequency, rats microinjected with insulin failed to discriminate ratiometric enantiomers; considered a difficult task. Microinjection of glucose prevented discrimination of odorants of different chain-lengths, whereas injection of margatoxin increased the rate of habituation to repeated odor stimulation and enhanced discrimination. These data suggest that metabolic signaling pathways that are present in the aPCtx are capable of neuronal modulation and changing complex olfactory behaviors in higher olfactory centers.
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Affiliation(s)
- Dolly Al Koborssy
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.,Department of Biological Science, The Florida State University, Tallahassee, FL, USA
| | - Brigitte Palouzier-Paulignan
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/CNRS UMR5292 Team Olfaction: From Coding to Memory, 50 Av. Tony Garnier, 69366, Lyon, France
| | - Vincent Canova
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/CNRS UMR5292 Team Olfaction: From Coding to Memory, 50 Av. Tony Garnier, 69366, Lyon, France
| | - Marc Thevenet
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/CNRS UMR5292 Team Olfaction: From Coding to Memory, 50 Av. Tony Garnier, 69366, Lyon, France
| | - Debra Ann Fadool
- Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.,Institute of Molecular Biophysics, The Florida State University, Tallahassee, FL, USA.,Department of Biological Science, The Florida State University, Tallahassee, FL, USA
| | - Andrée Karyn Julliard
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/CNRS UMR5292 Team Olfaction: From Coding to Memory, 50 Av. Tony Garnier, 69366, Lyon, France.
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36
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Bagnoli E, FitzGerald U. Mitral cells and the glucagon-like peptide 1 receptor: The sweet smell of success? Eur J Neurosci 2018; 49:422-439. [PMID: 30120857 DOI: 10.1111/ejn.14115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 07/19/2018] [Accepted: 08/03/2018] [Indexed: 12/11/2022]
Abstract
The olfactory bulb (OB) is often affected at very early stages of neurodegenerative disorders, in the so-called "prodromal" phase. In Parkinson's disease (PD), olfactory disturbances appear years before motor symptoms arise. Additionally, pathological alpha-synuclein aggregates are found in olfactory regions before spreading to other areas of the brain. Being positioned at the frontier between the brain and a potentially hostile environment, could explain the particular vulnerability of the OB. Mitral cells (MCs), the principal projecting neurons of the olfactory system, are involved in the pathogenesis and in the prion-like progression of PD. They are affected by Lewy pathology and are thought to contribute to the axonal transport of misfolded alpha-synuclein to other regions of the brain. Here, we first describe the main markers reported to distinguish MCs from other olfactory neurons. We focus on the glucagon-like peptide 1 receptor (GLP-1R), a membrane protein specifically expressed in MCs. After summarizing OB pathology, we explore the idea of targeting specifically MCs with GLP-1 or its analogues. Exenatide has shown great promise as a neuroprotective and neurorestorative agent and has been used in a clinical trial for clinical PD. Since GLP-1R activation has the ability to mitigate many facets of prodromal PD pathology, we postulate that once a robust biomarker is in place that is capable of identifying individuals in the prodromal phase of PD, homing in on GLP-1R could assist in deferring, or eradicating to a significant degree, the clinical manifestation of this debilitating human disorder.
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Affiliation(s)
- Enrico Bagnoli
- CÚRAM, Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland.,Galway Neuroscience Centre, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Una FitzGerald
- CÚRAM, Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland.,Galway Neuroscience Centre, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
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Peripheral Gene Therapeutic Rescue of an Olfactory Ciliopathy Restores Sensory Input, Axonal Pathfinding, and Odor-Guided Behavior. J Neurosci 2018; 38:7462-7475. [PMID: 30061191 DOI: 10.1523/jneurosci.0084-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 01/08/2023] Open
Abstract
Cilia of olfactory sensory neurons (OSNs) are the primary site of odor binding; hence, their loss results in anosmia, a clinical manifestation of pleiotropic ciliopathies for which there are no curative therapies. We used OSN-specific Ift88 knock-out mice (Ift88osnKO) of both sexes to examine the mechanisms of ciliopathy-induced olfactory dysfunction and the potential for gene replacement to rescue odorant detection, restore olfactory circuitry, and restore odor-guided behaviors. Loss of OSN cilia in Ift88osnKO mice resulted in substantially reduced odor detection and odor-driven synaptic activity in the olfactory bulb (OB). Defects in OSN axon targeting to the OB were also observed in parallel with aberrant odor-guided behavior. Intranasal gene delivery of wild-type IFT88 to Ift88osnKO mice rescued OSN ciliation and peripheral olfactory function. Importantly, this recovery of sensory input in a limited number of mature OSNs was sufficient to restore axonal targeting in the OB of juvenile mice, and with delayed onset in adult mice. In addition, restoration of sensory input re-established course odor-guided behaviors. These findings highlight the spare capacity of the olfactory epithelium and the plasticity of primary synaptic input into the central olfactory system. The restoration of peripheral and central neuronal function supports the potential for treatment of ciliopathy-related anosmia using gene therapy.SIGNIFICANCE STATEMENT Ciliopathies, for which there are no curative therapies, are genetic disorders that alter cilia morphology and/or function in numerous tissue types, including the olfactory system, leading to sensory dysfunction. We show that in vivo intranasal gene delivery restores peripheral olfactory function in a ciliopathy mouse model, including axonal targeting in the juvenile and adult olfactory bulb. Gene therapy also demonstrated restoration of olfactory perception by rescuing odor-guided behaviors. Understanding the therapeutic window and viability for gene therapy to restore odor detection and perception may facilitate translation of therapies to ciliopathy patients with olfactory dysfunctions.
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38
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Di Lucente J, Nguyen HM, Wulff H, Jin LW, Maezawa I. The voltage-gated potassium channel Kv1.3 is required for microglial pro-inflammatory activation in vivo. Glia 2018; 66:1881-1895. [PMID: 30043400 DOI: 10.1002/glia.23457] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 04/26/2018] [Accepted: 05/02/2018] [Indexed: 11/09/2022]
Abstract
Microglia show a rich repertoire of activation patterns regulated by a complex ensemble of surface ion channels, receptors, and transporters. We and others have investigated whether microglia vary their K+ channel expression as a means to achieve functional diversity. However, most of the prior studies were conducted using in vitro models such as BV2 cells, primary microglia, or brain slices in culture, which may not accurately reflect microglia physiology in adult individuals. Here we employed an in vivo mouse model of selective innate immune activation by intracerebroventricular injection of lipopolysaccharides (ICV-LPS) to determine the role of the voltage-gated Kv1.3 channel in LPS-induced M1-like microglial activation. Using microglia acutely isolated from adult brains, we detected Kv1.3 and Kir2.1 currents, and found that ICV-LPS increased the current density and RNA expression of Kv1.3 but did not affect those of Kir2.1. Genetic knockout of Kv1.3 abolished LPS-induced microglial activation exemplified by Iba-1 immunoreactivity and expression of pro-inflammatory mediators such as IL-1β, TNF-α, IL-6, and iNOS. Moreover, Kv1.3 knockout mitigated the LPS-induced impairment of hippocampal long-term potentiation (hLTP), suggesting that Kv1.3 activity regulates pro-inflammatory microglial neurotoxicity. Pharmacological intervention using PAP-1, a small molecule that selectively blocks homotetrameric Kv1.3 channels, achieved anti-inflammatory and hLTP-recovery effects similar to Kv1.3 knockout. We conclude that Kv1.3 is required for microglial M1-like pro-inflammatory activation in vivo. A significant implication of our in vivo data is that Kv1.3 blockers could be therapeutic candidates for neurological diseases where microglia-mediated neurotoxicity is implicated in the pathogenesis.
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Affiliation(s)
- Jacopo Di Lucente
- From the Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California
| | - Hai M Nguyen
- Department of Pharmacology, University of California, Davis, California
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, California
| | - Lee-Way Jin
- From the Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California
| | - Izumi Maezawa
- From the Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California
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39
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Kv1.3 activity perturbs the homeostatic properties of astrocytes in glioma. Sci Rep 2018; 8:7654. [PMID: 29769580 PMCID: PMC5955950 DOI: 10.1038/s41598-018-25940-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 05/02/2018] [Indexed: 01/06/2023] Open
Abstract
Glial cells actively maintain the homeostasis of brain parenchyma, regulating neuronal excitability and preserving the physiological composition of the extracellular milieu. Under pathological conditions, some functions of glial cells could be compromised, exacerbating the neurotoxic processes. We investigated if the homeostatic activities of astrocytes and microglia could be modulated by the voltage-gated K+ channel Kv1.3. To this end we used in vitro and in vivo systems to model cell-to-cell interactions in tumoral conditions, using a specific inhibitor of Kv1.3 channels, 5-(4-phenoxybutoxy) psoralen (PAP-1). We demonstrated that PAP-1 increases astrocytic glutamate uptake, reduces glioma-induced neurotoxicity, and decreases microglial migration and phagocytosis. We also found in a tumor blood brain barrier model that Kv1.3 activity is required for its integrity. The crucial role of Kv1.3 channels as modulators of glial cell activity was confirmed in a mouse model of glioma, where PAP-1 treatment reduces tumor volume only in the presence of active glutamate transporters GLT-1. In the same mouse model, PAP-1 reduces astrogliosis and microglial infiltration. PAP-1 also reduces tumor cell invasion. All these findings point to Kv1.3 channels as potential targets to re-instruct glial cells toward their homeostatic functions, in the context of brain tumors.
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40
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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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41
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Rotermund N, Winandy S, Fischer T, Schulz K, Fregin T, Alstedt N, Buchta M, Bartels J, Carlström M, Lohr C, Hirnet D. Adenosine A 1 receptor activates background potassium channels and modulates information processing in olfactory bulb mitral cells. J Physiol 2018; 596:717-733. [PMID: 29274133 DOI: 10.1113/jp275503] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/07/2017] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Adenosine is a widespread neuromodulator in the mammalian brain, but whether it affects information processing in sensory system(s) remains largely unknown. Here we show that adenosine A1 receptors hyperpolarize mitral cells, one class of principal neurons that propagate odour information from the olfactory bulb to higher brain areas, by activation of background K+ channels. The adenosine-modulated background K+ channels belong to the family of two-pore domain K+ channels. Adenosine reduces spontaneous activity of mitral cells, whereas action potential firing evoked by synaptic input upon stimulation of sensory neurons is not affected, resulting in a higher ratio of evoked firing (signal) over spontaneous firing (noise) and hence an improved signal-to-noise ratio. The study shows for the first time that adenosine influences fine-tuning of the input-output relationship in sensory systems. ABSTRACT Neuromodulation by adenosine is of critical importance in many brain regions, but the role of adenosine in olfactory information processing has not been studied so far. We investigated the effects of adenosine on mitral cells, which are projection neurons of the olfactory bulb. Significant expression of A1 and A2A receptors was found in mitral cells, as demonstrated by in situ hybridization. Application of adenosine in acute olfactory bulb slices hyperpolarized mitral cells in wild-type but not in adenosine A1 receptor knockout mice. Adenosine-induced hyperpolarization was mediated by background K+ currents that were reduced by halothane and bupivacaine, which are known to inhibit two-pore domain K+ (K2P) channels. In mitral cells, electrical stimulation of axons of olfactory sensory neurons evoked synaptic currents, which can be considered as input signals, while spontaneous firing independent of sensory input can be considered as noise. Synaptic currents were not affected by adenosine, while adenosine reduced spontaneous firing, leading to an increase in the signal-to-noise ratio of mitral cell firing. Our findings demonstrate that A1 adenosine receptors activate two-pore domain K+ channels, which increases the signal-to-noise ratio of the input-output relationship in mitral cells and thereby modulates information processing in the olfactory bulb.
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Affiliation(s)
- Natalie Rotermund
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Svenja Winandy
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Timo Fischer
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Kristina Schulz
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Torsten Fregin
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Nadine Alstedt
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Melanie Buchta
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Janick Bartels
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, Nanna Svartz Väg 2, Stockholm, 17177, Sweden
| | - Christian Lohr
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Daniela Hirnet
- Division of Neurophysiology, Institute of Zoology, University of Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
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42
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Zaghloul H, Pallayova M, Al-Nuaimi O, Hovis KR, Taheri S. Association between diabetes mellitus and olfactory dysfunction: current perspectives and future directions. Diabet Med 2018; 35:41-52. [PMID: 29108100 DOI: 10.1111/dme.13542] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/31/2017] [Indexed: 12/28/2022]
Abstract
The increasing global prevalence of diabetes mellitus presents a significant challenge to healthcare systems today. Although diabetic retinopathy, nephropathy and neuropathy are well-established complications of diabetes, there is a paucity of research examining the impact of dysglycaemia on the olfactory system. Olfaction is an important sense, playing a role in the safety, nutrition and quality of life of an individual, but its importance is often overlooked when compared with the other senses. As a result, olfactory dysfunction is often underdiagnosed. The present review article aims to present and discuss the available evidence on the relationship between diabetes and olfaction. It also explores the associations between olfactory dysfunction and diabetes complications that could explain the underlying pathogenesis. Finally, it summarizes the putative pathological mechanisms underlying olfactory dysfunction in diabetes that require further investigation.
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Affiliation(s)
- H Zaghloul
- Clinical Research Core, Weill Cornell Medicine, Doha, Qatar
- Department of Medicine, Weill Cornell Medicine, Doha, Qatar
- Weill Cornell Medicine, New York, NY, USA
| | - M Pallayova
- Clinical Research Core, Weill Cornell Medicine, Doha, Qatar
- Department of Medicine, Weill Cornell Medicine, Doha, Qatar
- Weill Cornell Medicine, New York, NY, USA
| | - O Al-Nuaimi
- Carnegie Mellon University, Doha, Qatar
- Carnegie Mellon University, Pittsburgh, PA, USA
| | - K R Hovis
- Carnegie Mellon University, Doha, Qatar
- Carnegie Mellon University, Pittsburgh, PA, USA
| | - S Taheri
- Clinical Research Core, Weill Cornell Medicine, Doha, Qatar
- Department of Medicine, Weill Cornell Medicine, Doha, Qatar
- Weill Cornell Medicine, New York, NY, USA
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43
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Chen YJ, Nguyen HM, Maezawa I, Jin LW, Wulff H. Inhibition of the potassium channel Kv1.3 reduces infarction and inflammation in ischemic stroke. Ann Clin Transl Neurol 2017; 5:147-161. [PMID: 29468176 PMCID: PMC5817832 DOI: 10.1002/acn3.513] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/10/2017] [Accepted: 11/20/2017] [Indexed: 12/26/2022] Open
Abstract
Objective Inhibitors of the voltage‐gated K+ channel Kv1.3 are currently in development as immunomodulators for the treatment of autoimmune diseases. As Kv1.3 is also expressed on microglia and has been shown to be specifically up‐regulated on “M1‐like” microglia, we here tested the therapeutic hypothesis that the brain‐penetrant small‐molecule Kv1.3‐inhibitor PAP‐1 reduces secondary inflammatory damage after ischemia/reperfusion. Methods We studied microglial Kv1.3 expression using electrophysiology and immunohistochemistry, and evaluated PAP‐1 in hypoxia‐exposed organotypic hippocampal slices and in middle cerebral artery occlusion (MCAO) with 8 days of reperfusion in both adult male C57BL/6J mice (60 min MCAO) and adult male Wistar rats (90 min MCAO). In both models, PAP‐1 administration was started 12 h after reperfusion. Results We observed Kv1.3 staining on activated microglia in ischemic infarcts in mice, rats, and humans and found higher Kv1.3 current densities in acutely isolated microglia from the infarcted hemisphere than in microglia isolated from the contralateral hemisphere of MCAO mice. PAP‐1 reduced microglia activation and increased neuronal survival in hypoxia‐exposed hippocampal slices as effectively as minocycline. In mouse MCAO, PAP‐1 dose‐dependently reduced infarct area, improved neurological deficit score, and reduced brain levels of IL‐1β and IFN‐γ without affecting IL‐10 and brain‐derived nerve growth factor (BDNF) levels or inhibiting ongoing phagocytosis. The beneficial effects on infarct area and neurological deficit score were reproduced in rats providing confirmation in a second species. Interpretation Our findings suggest that Kv1.3 constitutes a promising therapeutic target for preferentially inhibiting “M1‐like” inflammatory microglia/macrophage functions in ischemic stroke.
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Affiliation(s)
- Yi-Je Chen
- Department of Pharmacology University of California Davis 95616 California
| | - Hai M Nguyen
- Department of Pharmacology University of California Davis 95616 California
| | - Izumi Maezawa
- Department of Pathology and Laboratory Medicine University of California Davis, Sacramento 95817 California.,M.I.N.D. Institute University of California Davis 95817 California
| | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine University of California Davis, Sacramento 95817 California.,M.I.N.D. Institute University of California Davis 95817 California
| | - Heike Wulff
- Department of Pharmacology University of California Davis 95616 California
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44
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Blakemore LJ, Trombley PQ. Zinc as a Neuromodulator in the Central Nervous System with a Focus on the Olfactory Bulb. Front Cell Neurosci 2017; 11:297. [PMID: 29033788 PMCID: PMC5627021 DOI: 10.3389/fncel.2017.00297] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/06/2017] [Indexed: 12/19/2022] Open
Abstract
The olfactory bulb (OB) is central to the sense of smell, as it is the site of the first synaptic relay involved in the processing of odor information. Odor sensations are first transduced by olfactory sensory neurons (OSNs) before being transmitted, by way of the OB, to higher olfactory centers that mediate olfactory discrimination and perception. Zinc is a common trace element, and it is highly concentrated in the synaptic vesicles of subsets of glutamatergic neurons in some brain regions including the hippocampus and OB. In addition, zinc is contained in the synaptic vesicles of some glycinergic and GABAergic neurons. Thus, zinc released from synaptic vesicles is available to modulate synaptic transmission mediated by excitatory (e.g., N-methyl-D aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)) and inhibitory (e.g., gamma-aminobutyric acid (GABA), glycine) amino acid receptors. Furthermore, extracellular zinc can alter the excitability of neurons through effects on a variety of voltage-gated ion channels. Consistent with the notion that zinc acts as a regulator of neuronal activity, we and others have shown zinc modulation (inhibition and/or potentiation) of amino acid receptors and voltage-gated ion channels expressed by OB neurons. This review summarizes the locations and release of vesicular zinc in the central nervous system (CNS), including in the OB. It also summarizes the effects of zinc on various amino acid receptors and ion channels involved in regulating synaptic transmission and neuronal excitability, with a special emphasis on the actions of zinc as a neuromodulator in the OB. An understanding of how neuroactive substances such as zinc modulate receptors and ion channels expressed by OB neurons will increase our understanding of the roles that synaptic circuits in the OB play in odor information processing and transmission.
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Affiliation(s)
- Laura J Blakemore
- Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Department of Biological Science, Florida State UniversityTallahassee, FL, United States
| | - Paul Q Trombley
- Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Department of Biological Science, Florida State UniversityTallahassee, FL, United States
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45
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Pérez-García MT, Cidad P, López-López JR. The secret life of ion channels: Kv1.3 potassium channels and proliferation. Am J Physiol Cell Physiol 2017; 314:C27-C42. [PMID: 28931540 DOI: 10.1152/ajpcell.00136.2017] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Kv1.3 channels are involved in the switch to proliferation of normally quiescent cells, being implicated in the control of cell cycle in many different cell types and in many different ways. They modulate membrane potential controlling K+ fluxes, sense changes in potential, and interact with many signaling molecules through their intracellular domains. From a mechanistic point of view, we can describe the role of Kv1.3 channels in proliferation with at least three different models. In the "membrane potential model," membrane hyperpolarization resulting from Kv1.3 activation provides the driving force for Ca2+ influx required to activate Ca2+-dependent transcription. This model explains most of the data obtained from several cells from the immune system. In the "voltage sensor model," Kv1.3 channels serve mainly as sensors that transduce electrical signals into biochemical cascades, independently of their effect on membrane potential. Kv1.3-dependent proliferation of vascular smooth muscle cells (VSMCs) could fit this model. Finally, in the "channelosome balance model," the master switch determining proliferation may be related to the control of the Kv1.3 to Kv1.5 ratio, as described in glial cells and also in VSMCs. Since the three mechanisms cannot function independently, these models are obviously not exclusive. Nevertheless, they could be exploited differentially in different cells and tissues. This large functional flexibility of Kv1.3 channels surely gives a new perspective on their functions beyond their elementary role as ion channels, although a conclusive picture of the mechanisms involved in Kv1.3 signaling to proliferation is yet to be reached.
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Affiliation(s)
- M Teresa Pérez-García
- Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas , Valladolid , Spain
| | - Pilar Cidad
- Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas , Valladolid , Spain
| | - José R López-López
- Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas , Valladolid , Spain
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46
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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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47
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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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48
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Schwartz AB, Kapur A, Wang W, Huang Z, Fardone E, Palui G, Mattoussi H, Fadool DA. Margatoxin-bound quantum dots as a novel inhibitor of the voltage-gated ion channel Kv1.3. J Neurochem 2016; 140:404-420. [PMID: 27861889 DOI: 10.1111/jnc.13891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 10/24/2016] [Accepted: 10/31/2016] [Indexed: 01/01/2023]
Abstract
Venom-derived ion channel inhibitors have strong channel selectivity, potency, and stability; however, tracking delivery to their target can be challenging. Herein, we utilized luminescent quantum dots (QDs) conjugated to margatoxin (MgTx) as a traceable vehicle to target a voltage-dependent potassium channel, Kv1.3, which has a select distribution and well-characterized role in immunity, glucose metabolism, and sensory ability. We screened both unconjugated (MgTx) and conjugated MgTx (QD-MgTx) for their ability to inhibit Shaker channels Kv1.1 to Kv1.7 using patch-clamp electrophysiology in HEK293 cells. Our data indicate that MgTx inhibits 79% of the outward current in Kv1.3-transfected cells and that the QD-MgTx conjugate is able to achieve a similar level of block, albeit a slightly reduced efficacy (66%) and at a slower time course (50% block by 10.9 ± 1.1 min, MgTx; vs. 15.3 ± 1.2 min, QD-MgTx). Like the unbound peptide, the QD-MgTx conjugate inhibits both Kv1.3 and Kv1.2 at a 1 nM concentration, whereas it does not inhibit other screened Shaker channels. We tested the ability of QD-MgTx to inhibit native Kv1.3 expressed in the mouse olfactory bulb (OB). In brain slices of the OB, the conjugate acted similarly to MgTx to inhibit Kv1.3, causing an increased action potential firing frequency attributed to decreased intraburst duration rather than interspike interval. Our data demonstrate a retention of known biophysical properties associated with block of the vestibule of Kv1.3 by QD-MgTx conjugate compared to that of MgTx, inferring QDs could provide a useful tool to deliver ion channel inhibitors to targeted tissues in vivo.
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Affiliation(s)
- Austin B Schwartz
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, USA
| | - Anshika Kapur
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| | - Wentao Wang
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| | - Zhenbo Huang
- Program in Neuroscience, Florida State University, Tallahassee, Florida, USA
| | - Erminia Fardone
- Program in Neuroscience, Florida State University, Tallahassee, Florida, USA.,Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Goutam Palui
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| | - Hedi Mattoussi
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| | - Debra Ann Fadool
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, USA.,Program in Neuroscience, Florida State University, Tallahassee, Florida, USA.,Department of Biological Science, Florida State University, Tallahassee, Florida, USA
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49
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Reeves TM, Trimmer PA, Colley BS, Phillips LL. Targeting Kv1.3 channels to reduce white matter pathology after traumatic brain injury. Exp Neurol 2016; 283:188-203. [PMID: 27302680 PMCID: PMC4992637 DOI: 10.1016/j.expneurol.2016.06.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/31/2016] [Accepted: 06/10/2016] [Indexed: 02/07/2023]
Abstract
Axonal injury is present in essentially all clinically significant cases of traumatic brain injury (TBI). While no effective treatment has been identified to date, experimental TBI models have shown promising axonal protection using immunosuppressants FK506 and Cyclosporine-A, with treatment benefits attributed to calcineurin inhibition or protection of mitochondrial function. However, growing evidence suggests neuroprotective efficacy of these compounds may also involve direct modulation of ion channels, and in particular Kv1.3. The present study tested whether blockade of Kv1.3 channels, using Clofazimine (CFZ), would alleviate TBI-induced white matter pathology in rodents. Postinjury CFZ administration prevented suppression of compound action potential (CAP) amplitude in the corpus callosum of adult rats following midline fluid percussion TBI, with injury and treatment effects primarily expressed in unmyelinated CAPs. Kv1.3 protein levels in callosal tissue extracts were significantly reduced postinjury, but this loss was prevented by CFZ treatment. In parallel, CFZ also attenuated the injury-induced elevation in pro-inflammatory cytokine IL1-β. The effects of CFZ on glial function were further studied using mixed microglia/astrocyte cell cultures derived from P3-5 mouse corpus callosum. Cultures of callosal glia challenged with lipopolysaccharide exhibited a dramatic increase in IL1-β levels, accompanied by reactive morphological changes in microglia, both of which were attenuated by CFZ treatment. These results support a cell specific role for Kv1.3 signaling in white matter pathology after TBI, and suggest a treatment approach based on the blockade of these channels. This therapeutic strategy may be especially efficacious for normalizing neuro-glial interactions affecting unmyelinated axons after TBI.
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Affiliation(s)
- Thomas M Reeves
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
| | - Patricia A Trimmer
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
| | - Beverly S Colley
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
| | - Linda L Phillips
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
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50
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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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