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Rice CA, Stackman RW. The small conductance Ca 2+-activated K + channel activator GW542573X impairs hippocampal memory in C57BL/6J mice. Neuropharmacology 2024; 252:109960. [PMID: 38631563 DOI: 10.1016/j.neuropharm.2024.109960] [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: 01/30/2024] [Revised: 03/22/2024] [Accepted: 04/12/2024] [Indexed: 04/19/2024]
Abstract
Small conductance Ca2+-activated K+ (SK) channels, expressed throughout the CNS, are comprised of SK1, SK2 and SK3 subunits, assembled as homotetrameric or heterotetrameric proteins. SK channels expressed somatically modulate the excitability of neurons by mediating the medium component of the afterhyperpolarization. Synaptic SK channels shape excitatory postsynaptic potentials and synaptic plasticity. Such SK-mediated effects on neuronal excitability and activity-dependent synaptic strength likely underlie the modulatory influence of SK channels on memory encoding. Converging evidence indicates that several forms of long-term memory are facilitated by administration of the SK channel blocker, apamin, and impaired by administration of the pan-SK channel activator, 1-EBIO, or by overexpression of the SK2 subunit. The selective knockdown of dendritic SK2 subunits facilitates memory to a similar extent as that observed after systemic apamin. SK1 subunits co-assemble with SK2; yet the functional significance of SK1 has not been clearly defined. Here, we examined the effects of GW542573X, a drug that activates SK1 containing SK channels, as well as SK2/3, on several forms of long-term memory in male C57BL/6J mice. Our results indicate that pre-training, but not post-training, systemic GW542573X impaired object memory and fear memory in mice tested 24 h after training. Pre-training direct bilateral infusion of GW542573X into the CA1 of hippocampus impaired object memory encoding. These data suggest that systemic GW542573X impairs long-term memory. These results add to growing evidence that SK2 subunit-, and SK1 subunit-, containing SK channels can regulate behaviorally triggered synaptic plasticity necessary for encoding hippocampal-dependent memory.
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Affiliation(s)
- Claire A Rice
- Department of Psychology, Jupiter Life Science Initiative and the Stiles-Nicholson Brain Institute, Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL, 33458, USA
| | - Robert W Stackman
- Department of Psychology, Jupiter Life Science Initiative and the Stiles-Nicholson Brain Institute, Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL, 33458, USA.
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2
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Nageeb Hasan SM, Clarke CL, McManamon Strand TP, Bambico FR. Putative pathological mechanisms of late-life depression and Alzheimer's Disease. Brain Res 2023:148423. [PMID: 37244602 DOI: 10.1016/j.brainres.2023.148423] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by progressive impairment in cognition and memory. AD is accompanied by several neuropsychiatric symptoms, with depression being the most prominent. Although depression has long been known to be associated with AD, controversial findings from preclinical and clinical studies have obscured the precise nature of this association. However recent evidence suggests that depression could be a prodrome or harbinger of AD. Evidence indicates that the major central serotonergic nucleus-the dorsal raphe nucleus (DRN)-shows very early AD pathology: neurofibrillary tangles made of hyperphosphorylated tau protein and degenerated neurites. AD and depression share common pathophysiologies, including functional deficits of the serotonin (5-HT) system. 5-HT receptors have modulatory effects on the progression of AD pathology i.e., reduction in Aβ load, increased hyper-phosphorylation of tau, decreased oxidative stress etc. Moreover, preclinical models show a role for specific channelopathies that result in abnormal regional activational and neuroplasticity patterns. One of these concerns the pathological upregulation of the small conductance calcium-activated potassium (SK) channel in corticolimbic structure. This has also been observed in the DRN in both diseases. The SKC is a key regulator of cell excitability and long-term potentiation (LTP). SKC over-expression is positively correlated with aging and cognitive decline, and is evident in AD. Pharmacological blockade of SKCs has been reported to reverse symptoms of depression and AD. Thus, aberrant SKC functioning could be related to depression pathophysiology and diverts its late-life progression towards the development of AD. We summarize findings from preclinical and clinical studies suggesting a molecular linkage between depression and AD pathology. We also provide a rationale for considering SKCs as a novel pharmacological target for the treatment of AD-associated symptoms.
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Affiliation(s)
- S M Nageeb Hasan
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada.
| | - Courtney Leigh Clarke
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada
| | | | - Francis Rodriguez Bambico
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada; Behavioural Neurobiology Laboratory, Centre for Addiction and Mental Health, Toronto, ON, M5T1R8, Canada
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3
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Nam YW, Downey M, Rahman MA, Cui M, Zhang M. Channelopathy of small- and intermediate-conductance Ca 2+-activated K + channels. Acta Pharmacol Sin 2023; 44:259-267. [PMID: 35715699 PMCID: PMC9889811 DOI: 10.1038/s41401-022-00935-1] [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: 05/01/2022] [Accepted: 05/31/2022] [Indexed: 02/04/2023] Open
Abstract
Small- and intermediate-conductance Ca2+-activated K+ (KCa2.x/KCa3.1 also called SK/IK) channels are gated exclusively by intracellular Ca2+. The Ca2+ binding protein calmodulin confers sub-micromolar Ca2+ sensitivity to the channel-calmodulin complex. The calmodulin C-lobe is constitutively associated with the proximal C-terminus of the channel. Interactions between calmodulin N-lobe and the channel S4-S5 linker are Ca2+-dependent, which subsequently trigger conformational changes in the channel pore and open the gate. KCNN genes encode four subtypes, including KCNN1 for KCa2.1 (SK1), KCNN2 for KCa2.2 (SK2), KCNN3 for KCa2.3 (SK3), and KCNN4 for KCa3.1 (IK). The three KCa2.x channel subtypes are expressed in the central nervous system and the heart. The KCa3.1 subtype is expressed in the erythrocytes and the lymphocytes, among other peripheral tissues. The impact of dysfunctional KCa2.x/KCa3.1 channels on human health has not been well documented. Human loss-of-function KCa2.2 mutations have been linked with neurodevelopmental disorders. Human gain-of-function mutations that increase the apparent Ca2+ sensitivity of KCa2.3 and KCa3.1 channels have been associated with Zimmermann-Laband syndrome and hereditary xerocytosis, respectively. This review article discusses the physiological significance of KCa2.x/KCa3.1 channels, the pathophysiology of the diseases linked with KCa2.x/KCa3.1 mutations, the structure-function relationship of the mutant KCa2.x/KCa3.1 channels, and potential pharmacological therapeutics for the KCa2.x/KCa3.1 channelopathy.
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Affiliation(s)
- Young-Woo Nam
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, 92618, USA
| | - Myles Downey
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, 92618, USA
| | - Mohammad Asikur Rahman
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, 92618, USA
| | - Meng Cui
- Department of Pharmaceutical Sciences, Northeastern University School of Pharmacy, Boston, MA, 02115, USA
| | - Miao Zhang
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, 92618, USA.
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4
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Jahangir M, Li L, Zhou JS, Lang B, Wang XP. L1 Retrotransposons: A Potential Endogenous Regulator for Schizophrenia. Front Genet 2022; 13:878508. [PMID: 35832186 PMCID: PMC9271560 DOI: 10.3389/fgene.2022.878508] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
The long interspersed nuclear elements 1 (LINE-1/L1s) are the only active autonomous retrotransposons found in humans which can integrate anywhere in the human genome. They can expand the genome and thus bring good or bad effects to the host cells which really depends on their integration site and associated polymorphism. LINE-1 retrotransposition has been found participating in various neurological disorders such as autism spectrum disorder, Alzheimer’s disease, major depression disorder, post-traumatic stress disorder and schizophrenia. Despite the recent progress, the roles and pathological mechanism of LINE-1 retrotransposition in schizophrenia and its heritable risks, particularly, contribution to “missing heritability” are yet to be determined. Therefore, this review focuses on the potentially etiological roles of L1s in the development of schizophrenia, possible therapeutic choices and unaddressed questions in order to shed lights on the future research.
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Affiliation(s)
| | | | | | - Bing Lang
- *Correspondence: Bing Lang, ; Xiao-Ping Wang,
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5
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Channelopathy-causing mutations in the S 45A/S 45B and HA/HB helices of K Ca2.3 and K Ca3.1 channels alter their apparent Ca 2+ sensitivity. Cell Calcium 2022; 102:102538. [PMID: 35030515 PMCID: PMC8844225 DOI: 10.1016/j.ceca.2022.102538] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 12/11/2022]
Abstract
Small- and intermediate-conductance Ca2+-activated potassium (KCa2.x and KCa3.1, also called SK and IK) channels are activated exclusively by a Ca2+-calmodulin gating mechanism. Wild-type KCa2.3 channels have a Ca2+ EC50 value of ∼0.3 μM, while the apparent Ca2+ sensitivity of wild-type KCa3.1 channels is ∼0.27 μM. Heterozygous genetic mutations of KCa2.3 channels have been associated with Zimmermann-Laband syndrome and idiopathic noncirrhotic portal hypertension, while KCa3.1 channel mutations were reported in hereditary xerocytosis patients. KCa2.3_S436C and KCa2.3_V450L channels with mutations in the S45A/S45B helices exhibited hypersensitivity to Ca2+. The corresponding mutations in KCa3.1 channels also elevated the apparent Ca2+ sensitivity. KCa3.1_S314P, KCa3.1_A322V and KCa3.1_R352H channels with mutations in the HA/HB helices are hypersensitive to Ca2+, whereas KCa2.3 channels with the equivalent mutations are not. The different effects of the equivalent mutations in the HA/HB helices on the apparent Ca2+ sensitivity of KCa2.3 and KCa3.1 channels may imply distinct modulation of the two channel subtypes by the HA/HB helices. AP14145 reduced the apparent Ca2+ sensitivity of the hypersensitive mutant KCa2.3 channels, suggesting the potential therapeutic usefulness of negative gating modulators.
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Nashed MG, Waye S, Hasan SMN, Nguyen D, Wiseman M, Zhang J, Lau H, Dinesh OC, Raymond R, Greig IR, Bambico FR, Nobrega JN. Antidepressant activity of pharmacological and genetic deactivation of the small-conductance calcium-activated potassium channel subtype-3. Psychopharmacology (Berl) 2022; 239:253-266. [PMID: 34982171 DOI: 10.1007/s00213-021-06045-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 12/13/2021] [Indexed: 11/25/2022]
Abstract
RATIONALE The voltage-insensitive, small-conductance calcium-activated potassium (SK) channel is a key regulator of neuronal depolarization and is implicated in the pathophysiology of depressive disorders. OBJECTIVE We ascertained whether the SK channel is impaired in the chronic unpredictable stress (CUS) model and whether it can serve as a molecular target of antidepressant action. METHODS We assessed the depressive-like behavioral phenotype of CUS-exposed rats and performed post-mortem SK channel binding and activity-dependent zif268 mRNA analyses on their brains. To begin an assessment of SK channel subtypes involved, we examined the effects of genetic and pharmacological inhibition of the SK3 channel using conditional knockout mice and selective SK3 channel negative allosteric modulators (NAMs). RESULTS We found that [125I]apamin binding to SK channels is increased in the prefrontal cortex and decreased in the hippocampus, an effect that was associated with reciprocal levels of zif268 mRNA transcripts indicating abnormal regional cell activity in this model. We found that genetic and pharmacological manipulations significantly decreased immobility in the forced swim test without altering general locomotor activity, a hallmark of antidepressant-like activity. CONCLUSIONS Taken together, these findings link depression-related neural and behavioral pathophysiology with abnormal SK channel functioning and suggest that this can be reversed by the selective inhibition of SK3 channels.
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Affiliation(s)
- Mina G Nashed
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
| | - Shannon Waye
- Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland & Labrador, A1B 3X9, Canada
| | - S M Nageeb Hasan
- Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland & Labrador, A1B 3X9, Canada
| | - Diana Nguyen
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
| | - Micaela Wiseman
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
| | - Jing Zhang
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
| | - Harry Lau
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
| | - O Chandani Dinesh
- Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland & Labrador, A1B 3X9, Canada
| | - Roger Raymond
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
| | - Iain R Greig
- Institute of Medical Sciences, University of Aberdeen, King's College, Aberdeen, AB25 2ZD, Scotland
| | - Francis Rodriguez Bambico
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada. .,Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland & Labrador, A1B 3X9, Canada.
| | - José N Nobrega
- Behavioural Neurobiology Laboratory, Research Imaging Center, Centre for Addiction and Mental Health (CAMH), Toronto, ON, M5T 1R8, Canada
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7
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Xiao X, Zhang CY, Zhang Z, Hu Z, Li M, Li T. Revisiting tandem repeats in psychiatric disorders from perspectives of genetics, physiology, and brain evolution. Mol Psychiatry 2022; 27:466-475. [PMID: 34650204 DOI: 10.1038/s41380-021-01329-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 09/16/2021] [Accepted: 09/28/2021] [Indexed: 01/28/2023]
Abstract
Genome-wide association studies (GWASs) have revealed substantial genetic components comprised of single nucleotide polymorphisms (SNPs) in the heritable risk of psychiatric disorders. However, genetic risk factors not covered by GWAS also play pivotal roles in these illnesses. Tandem repeats, which are likely functional but frequently overlooked by GWAS, may account for an important proportion in the "missing heritability" of psychiatric disorders. Despite difficulties in characterizing and quantifying tandem repeats in the genome, studies have been carried out in an attempt to describe impact of tandem repeats on gene regulation and human phenotypes. In this review, we have introduced recent research progress regarding the genomic distribution and regulatory mechanisms of tandem repeats. We have also summarized the current knowledge of the genetic architecture and biological underpinnings of psychiatric disorders brought by studies of tandem repeats. These findings suggest that tandem repeats, in candidate psychiatric risk genes or in different levels of linkage disequilibrium (LD) with psychiatric GWAS SNPs and haplotypes, may modulate biological phenotypes related to psychiatric disorders (e.g., cognitive function and brain physiology) through regulating alternative splicing, promoter activity, enhancer activity and so on. In addition, many tandem repeats undergo tight natural selection in the human lineage, and likely exert crucial roles in human brain evolution. Taken together, the putative roles of tandem repeats in the pathogenesis of psychiatric disorders is strongly implicated, and using examples from previous literatures, we wish to call for further attention to tandem repeats in the post-GWAS era of psychiatric disorders.
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Affiliation(s)
- Xiao Xiao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Chu-Yi Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Zhuohua Zhang
- Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Zhonghua Hu
- Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China. .,Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, Hunan, China. .,Eye Center of Xiangya Hospital and Hunan Key Laboratory of Ophthalmology, Central South University, Changsha, Hunan, China. .,National Clinical Research Center on Mental Disorders, Changsha, Hunan, China.
| | - Ming Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China. .,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China. .,KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
| | - Tao Li
- Affiliated Mental Health Center & Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. .,Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China.
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8
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Trombetta-Lima M, Krabbendam IE, Dolga AM. Calcium-activated potassium channels: implications for aging and age-related neurodegeneration. Int J Biochem Cell Biol 2020; 123:105748. [PMID: 32353429 DOI: 10.1016/j.biocel.2020.105748] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/11/2020] [Accepted: 04/14/2020] [Indexed: 12/16/2022]
Abstract
Population aging, as well as the handling of age-associated diseases, is a worldwide increasing concern. Among them, Alzheimer's disease stands out as the major cause of dementia culminating in full dependence on other people for basic functions. However, despite numerous efforts, in the last decades, there was no new approved therapeutic drug for the treatment of the disease. Calcium-activated potassium channels have emerged as a potential tool for neuronal protection by modulating intracellular calcium signaling. Their subcellular localization is determinant of their functional effects. When located on the plasma membrane of neuronal cells, they can modulate synaptic function, while their activation at the inner mitochondrial membrane has a neuroprotective potential via the attenuation of mitochondrial reactive oxygen species in conditions of oxidative stress. Here we review the dual role of these channels in the aging phenotype and Alzheimer's disease pathology and discuss their potential use as a therapeutic tool.
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Affiliation(s)
- Marina Trombetta-Lima
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands; Medical School, Neurology Department, University of São Paulo (USP), 01246903 São Paulo, Brazil
| | - Inge E Krabbendam
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands
| | - Amalia M Dolga
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands.
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9
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Meng L, Zhao Y, Qu D, Xie Z, Guo X, Zhu Z, Chen Z, Zhang L, Li W, Cao Z, Tian C, Wu Y. Ion channel modulation by scorpion hemolymph and its defensin ingredients highlights origin of neurotoxins in telson formed in Paleozoic scorpions. Int J Biol Macromol 2020; 148:351-363. [PMID: 31954123 DOI: 10.1016/j.ijbiomac.2020.01.133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 12/27/2022]
Abstract
An increasing number of scorpion fossils indicate that the venomous telson developed from the sharp telson in sea scorpions into the extant scorpion-like telson in aquatic scorpions in the Paleozoic Era and then further evolved into the fetal venom system. This hypothesis led us to evaluate the inhibition of scorpion venom-sensitive potassium channels by hemolymph from the scorpion Mesobuthus martensii. Scorpion hemolymph diluted 1:10 inhibited Kv1.1, Kv1.2, Kv1.3 and SK3 potassium channel currents by 76.4%, 90.2%, 85.8%, and 52.8%, respectively. These discoveries encouraged us to investigate the functional similarity between the more ancient defensin ingredients in hemolymph and the evolved neurotoxins in the venom. In addition to the expression of the representative defensin BmKDfsin3 and BmKDfsin5 in both venomous and non-venomous tissues, NMR analysis revealed structural similarities between scorpion defensin and neurotoxin. Functional experiments further indicated that scorpion defensin used the same mechanism as classical neurotoxin to block the neurotoxin-sensitive Kv1.1, Kv1.2, Kv1.3 and SK3 channels. These findings emphasize the likelihood that scorpion defensins evolved into neurotoxins that were adapted to the emergence of the scorpion telson from the sharp telson of sea scorpions into the extant scorpion-like telson in aquatic scorpions in the Paleozoic Era.
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Affiliation(s)
- Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yonghui Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Daliang Qu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China; School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Zili Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xingchen Guo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhanyong Zhu
- Department of Plastic Surgery, Renmin Hospital of Wuhan University, Wuhan 430072, China
| | - Zongyun Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Longhua Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China; School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Changlin Tian
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China; School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China.
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10
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Mi Z, Yang J, He Q, Zhang X, Xiao Y, Shu Y. Alterations of Electrophysiological Properties and Ion Channel Expression in Prefrontal Cortex of a Mouse Model of Schizophrenia. Front Cell Neurosci 2019; 13:554. [PMID: 31920555 PMCID: PMC6927988 DOI: 10.3389/fncel.2019.00554] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/02/2019] [Indexed: 11/13/2022] Open
Abstract
Maternal immune activation (MIA) and juvenile social isolation (SI) are two most prevalent and widely accepted environmental insults that could increase the propensity of psychiatric illnesses. Using a two-hit mouse model, we examined the impact of the combination of these two factors on animal behaviors, neuronal excitability and expressions of voltage-gated sodium (Nav) and small conductance calcium-activated potassium (SK) channels in the prefrontal cortex (PFC). We found that MIA-SI induced a number of schizophrenia-related behavioral deficits. Patch clamp recordings revealed alterations in electrophysiological properties of PFC layer-5 pyramidal cells, including hyperpolarized resting membrane potential (RMP), increased input resistance and enhanced medium after-hyperpolarization (mAHP). MIA-SI also increased the ratio of the maximal slope of somatodendritic potential to the peak slope of action potential upstroke, indicating a change in perisomatic Nav availability. Consistently, MIA-SI significantly increased the expression level of Nav1.2 and SK3 channels that contribute to the somatodendritic potential and the mAHP, respectively. Together, these changes may alter neuronal signaling in the PFC and behavioral states, representing a molecular imprint of environmental insults associated with neuropsychiatric illnesses.
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Affiliation(s)
- Zhen Mi
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Jun Yang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Quansheng He
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Xiaowen Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Yujie Xiao
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Yousheng Shu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.,IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
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11
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Gain-of-Function Mutations in KCNN3 Encoding the Small-Conductance Ca 2+-Activated K + Channel SK3 Cause Zimmermann-Laband Syndrome. Am J Hum Genet 2019; 104:1139-1157. [PMID: 31155282 DOI: 10.1016/j.ajhg.2019.04.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/15/2019] [Indexed: 01/16/2023] Open
Abstract
Zimmermann-Laband syndrome (ZLS) is characterized by coarse facial features with gingival enlargement, intellectual disability (ID), hypertrichosis, and hypoplasia or aplasia of nails and terminal phalanges. De novo missense mutations in KCNH1 and KCNK4, encoding K+ channels, have been identified in subjects with ZLS and ZLS-like phenotype, respectively. We report de novo missense variants in KCNN3 in three individuals with typical clinical features of ZLS. KCNN3 (SK3/KCa2.3) constitutes one of three members of the small-conductance Ca2+-activated K+ (SK) channels that are part of a multiprotein complex consisting of the pore-forming channel subunits, the constitutively bound Ca2+ sensor calmodulin, protein kinase CK2, and protein phosphatase 2A. CK2 modulates Ca2+ sensitivity of the channels by phosphorylating SK-bound calmodulin. Patch-clamp whole-cell recordings of KCNN3 channel-expressing CHO cells demonstrated that disease-associated mutations result in gain of function of the mutant channels, characterized by increased Ca2+ sensitivity leading to faster and more complete activation of KCNN3 mutant channels. Pretreatment of cells with the CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole revealed basal inhibition of wild-type and mutant KCNN3 channels by CK2. Analogous experiments with the KCNN3 p.Val450Leu mutant previously identified in a family with portal hypertension indicated basal constitutive channel activity and thus a different gain-of-function mechanism compared to the ZLS-associated mutant channels. With the report on de novo KCNK4 mutations in subjects with facial dysmorphism, hypertrichosis, epilepsy, ID, and gingival overgrowth, we propose to combine the phenotypes caused by mutations in KCNH1, KCNK4, and KCNN3 in a group of neurological potassium channelopathies caused by an increase in K+ conductance.
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12
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Pan JX, Deng FL, Zeng BH, Zheng P, Liang WW, Yin BM, Wu J, Dong MX, Luo YY, Wang HY, Wei H, Xie P. Absence of gut microbiota during early life affects anxiolytic Behaviors and monoamine neurotransmitters system in the hippocampal of mice. J Neurol Sci 2019; 400:160-168. [PMID: 30954660 DOI: 10.1016/j.jns.2019.03.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 02/17/2019] [Accepted: 03/28/2019] [Indexed: 12/21/2022]
Abstract
The gut microbiome is composed of an enormous number of microorganisms, generally regarded as commensal bacteria. Resident gut bacteria are an important contributor to health and significant evidence suggests that the presence of healthy and diverse gut microbiota is important for normal cognitive and emotional processing. Here we measured the expression of monoamine neurotransmitter-related genes in the hippocampus of germ-free (GF) mice and specific-pathogen-free (SPF) mice to explore the effect of gut microbiota on hippocampal monoamine functioning. In total, 19 differential expressed genes (Htr7, Htr1f, Htr3b, Drd3, Ddc, Maob, Tdo2, Fos, Creb1, Akt1, Gsk3a, Pik3ca, Pla2g5, Cyp2d22, Grk6, Ephb1, Slc18a1, Nr4a1, Gdnf) that could discriminate between the two groups were identified. Interestingly, GF mice displayed anxiolytic-like behavior compared to SPF mice, which were not reversed by colonization with gut microbiota from SPF mice. Besides, colonization of adolescent GF mice by gut microbiota was not sufficient to reverse the altered gene expression associated with their GF status. Taking these findings together, the absence of commensal microbiota during early life markedly affects hippocampal monoamine gene-regulation, which was associated with anxiolytic behaviors and monoamine neurological signs.
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Affiliation(s)
- Jun-Xi Pan
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China; Department of Clinical Laboratory, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Feng-Li Deng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China; School of Public Health and Management, Chongqing Medical University, Chongqing 400016, China; Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ben-Hua Zeng
- Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China; Department of Laboratory Animal Science, College of Basic Medical Sciences, Third Military Medical University, 400038 Chongqing, China
| | - Peng Zheng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Wei-Wei Liang
- Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Bang-Min Yin
- Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Jing Wu
- Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Mei-Xue Dong
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Yuan-Yuan Luo
- Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Hai-Yang Wang
- Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China
| | - Hong Wei
- Department of Laboratory Animal Science, College of Basic Medical Sciences, Third Military Medical University, 400038 Chongqing, China.
| | - Peng Xie
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing 400016, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016, China.
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Albers J, Pacilé S, Markus MA, Wiart M, Vande Velde G, Tromba G, Dullin C. X-ray-Based 3D Virtual Histology-Adding the Next Dimension to Histological Analysis. Mol Imaging Biol 2019; 20:732-741. [PMID: 29968183 DOI: 10.1007/s11307-018-1246-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Histology and immunohistochemistry of thin tissue sections have been the standard diagnostic procedure in many diseases for decades. This method is highly specific for particular tissue regions or cells, but mechanical sectioning of the specimens is required, which destroys the sample in the process and can lead to non-uniform tissue deformations. In addition, regions of interest cannot be located beforehand and the analysis is intrinsically two-dimensional. Micro X-ray computed tomography (μCT) on the other hand can provide 3D images at high resolution and allows for quantification of tissue structures, as well as the localization of small regions of interest. These advantages advocate the use of μCT for virtual histology tool with or without subsequent classical histology. This review summarizes the most recent examples of virtual histology and provides currently known possibilities of improving contrast and resolution of μCT. Following a background in μCT imaging, ex vivo staining procedures for contrast enhancement are presented as well as label-free virtual histology approaches and the technologies, which could rapidly advance it, such as phase-contrast CT. Novel approaches such as zoom tomography and nanoparticulate contrast agents will also be considered. The current evidence suggests that virtual histology may present a valuable addition to the workflow of histological analysis, potentially reducing the workload in pathology, refining tissue classification, and supporting the detection of small malignancies.
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Affiliation(s)
- J Albers
- Institute for Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany
| | - S Pacilé
- Department of Engineering and Architecture, University of Trieste, Trieste, Italy.,Elettra Sincrotrone Trieste, Trieste, Italy
| | - M A Markus
- Translational Molecular Imaging, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - M Wiart
- Univ Lyon, CarMeN Laboratory, INSERM, INRA, INSA Lyon, Université Claude Bernard Lyon 1, 69500, Bron, France
| | - G Vande Velde
- Department of Imaging and Pathology, Faculty of Medicine, KU Leuven-University of Leuven, Leuven, Belgium
| | - G Tromba
- Elettra Sincrotrone Trieste, Trieste, Italy
| | - C Dullin
- Institute for Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany. .,Elettra Sincrotrone Trieste, Trieste, Italy. .,Translational Molecular Imaging, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany.
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Koç MM, Aslan N, Kao AP, Barber AH. Evaluation of X-ray tomography contrast agents: A review of production, protocols, and biological applications. Microsc Res Tech 2019; 82:812-848. [PMID: 30786098 DOI: 10.1002/jemt.23225] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/02/2019] [Accepted: 01/12/2019] [Indexed: 12/25/2022]
Abstract
X-ray computed tomography is a strong tool that finds many applications both in medical applications and in the investigation of biological and nonbiological samples. In the clinics, X-ray tomography is widely used for diagnostic purposes whose three-dimensional imaging in high resolution helps physicians to obtain detailed image of investigated regions. Researchers in biological sciences and engineering use X-ray tomography because it is a nondestructive method to assess the structure of their samples. In both medical and biological applications, visualization of soft tissues and structures requires special treatment, in which special contrast agents are used. In this detailed report, molecule-based and nanoparticle-based contrast agents used in biological applications to enhance the image quality were compiled and reported. Special contrast agent applications and protocols to enhance the contrast for the biological applications and works to develop nanoparticle contrast agents to enhance the contrast for targeted drug delivery and general imaging applications were also assessed and listed.
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Affiliation(s)
- Mümin Mehmet Koç
- School of Engineering, University of Portsmouth, Portsmouth, United Kingdom.,Department of Physics, Kirklareli University, Kirklareli, Turkey
| | - Naim Aslan
- Department of Metallurgical and Materials Engineering, Munzur University, Tunceli, Turkey
| | - Alexander P Kao
- School of Engineering, University of Portsmouth, Portsmouth, United Kingdom
| | - Asa H Barber
- School of Engineering, London South Bank University, London, United Kingdom
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Tamadon H, Ghasemi Z, Ghasemi F, Hosseinmardi N, Vatanpour H, Janahmadi M. Characterization of Functional Effects of Two New Active Fractions Isolated From Scorpion Venom on Neuronal Ca 2+ Spikes: A Possible Action on Ca 2+-Dependent Dependent K + Channels. Basic Clin Neurosci 2019. [PMID: 31031893 PMCID: PMC6484188 DOI: 10.32598/bcn.9.10.352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION It is a long time that natural toxin research is conducted to unlock the medical potential of toxins. Although venoms-toxins cause pathophysiological conditions, they may be effective to treat several diseases. Since toxins including scorpion toxins target voltage-gated ion channels, they may have profound effects on excitable cells. Therefore, elucidating the cellular and electrophysiological impacts of toxins, particularly scorpion toxins would be helpful in future drug development opportunities. METHODS Intracellular recording was made from F1 cells of Helix aspersa in the presence of calcium Ringer solution in which Na+ and K+ channels were blocked. Then, the modulation of channel function in the presence of extracellular application of F4 and F6 toxins and kaliotoxin (KTX; 50 nM and 1 μM) was examined by assessing the electrophysiological characteristics of calcium spikes. RESULTS The two active toxin fractions, similar to KTX, a known Ca2+-activated K+ channel blocker, reduced the amplitude of AHP, enhanced the firing frequency of calcium spikes and broadened the duration of Ca2+ spikes. Therefore, it might be inferred that these two new fractions induce neuronal hyperexcitability possibly, in part, by blocking calcium-activated potassium channel current. However, this supposition requires further investigation using voltage clamping technique. CONCLUSION These toxin fractions may act as blocker of calcium-activated potassium channels.
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Affiliation(s)
- Hanieh Tamadon
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Ghasemi
- Department of Physiology, School of Medicine, Tarbiat
Modares University, Tehran, Iran
| | - Fatemeh Ghasemi
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Vatanpour
- Department of Toxicology and Pharmacology, School of
Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Corresponding Author: Mahyar
Janahmadi, PhD.Address: Department of Physiology, Neuroscience Research
Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Tel: +98 (21) 22439971
E-mail:;
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X-ray based virtual histology allows guided sectioning of heavy ion stained murine lungs for histological analysis. Sci Rep 2018; 8:7712. [PMID: 29769600 PMCID: PMC5955938 DOI: 10.1038/s41598-018-26086-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/01/2018] [Indexed: 01/10/2023] Open
Abstract
Examination of histological or immunohistochemically stained 2D sections of embedded tissue is one of the most frequently used tools in biomedical research and clinical routine. Since to date, targeted sectioning of specific regions of interest (ROI) in the sample is not possible, we aimed at developing a guided sectioning approach based on x-ray 3D virtual histology for heavy ion stained murine lung samples. For this purpose, we increased the contrast to noise ratio of a standard benchtop microCT by 5–10-fold using free-propagation phase contrast imaging and thus substantially improved image quality. We then show that microCT 3D datasets deliver more precise anatomical information and quantification of the sample than traditional histological sections, which display deformations of the tissue. To quantify these deformations caused by sectioning we developed the “Displacement Index (DI)”, which combines block-matching with the calculation of the local mutual information. We show that the DI substantially decreases when a femtosecond laser microtome is used for sections as opposed to a traditional microtome. In conclusion, our microCT based virtual histology approach can be used as a supplement and a guidance tool for traditional histology, providing 3D measurement capabilities and offering the ability to perform sectioning directly at an ROI.
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3D virtual histology of murine kidneys -high resolution visualization of pathological alterations by micro computed tomography. Sci Rep 2018; 8:1407. [PMID: 29362427 PMCID: PMC5780475 DOI: 10.1038/s41598-018-19773-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/27/2017] [Indexed: 12/18/2022] Open
Abstract
The increasing number of patients with end stage chronic kidney disease not only calls for novel therapeutics but also for pioneering research using convincing preclinical disease models and innovative analytical techniques. The aim of this study was to introduce a virtual histology approach using micro computed tomography (µCT) for the entire murine kidney in order to close the gap between single slice planar histology and a 3D high resolution dataset. An ex vivo staining protocol based on phosphotungstic acid diffusion was adapted to enhance renal soft tissue x-ray attenuation. Subsequent CT scans allowed (i) the detection of the renal cortex, medulla and pelvis in greater detail, (ii) the analysis of morphological alterations, (iii) the quantification of the volume as well as the radio-opacity of these portions and (iv) the quantification of renal fibrotic remodeling based on altered radio-opacity using the unilateral ureteral obstruction model. Thus, virtual histology based on PTA contrast enhanced CT will in future help to refine the outcome of preclinical research on kidney associated murine disease models.
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18
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Lázaro J, Hertel M, LaPoint S, Wikelski M, Stiehler M, Dechmann DKN. Cognitive skills of common shrews ( Sorex araneus) vary with seasonal changes in skull size and brain mass. ACTA ACUST UNITED AC 2018; 221:jeb.166595. [PMID: 29170257 DOI: 10.1242/jeb.166595] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/17/2017] [Indexed: 02/01/2023]
Abstract
In a rare phenomenon, shrews and a few other species cope with seasonal environments by reducing and regrowing brain size, potentially at the cost of changes in cognitive abilities. Here, we confirm an extensive seasonal shrinkage (21.4%) and regrowth (17.0%) of brain mass in winter and spring, respectively, in the common shrew (Sorex araneus L.) in Southern Germany. In a spatial learning task experiment, individuals with reduced winter brain size covered larger distances to find food, compared with the relatively large-brained summer juveniles and regrown spring adults. By reducing their brain mass, these shrews may reduce their energetic demands, but at the cost of cognitive performance, implying a complex trade-off for coping with seasonally fluctuating resources. These results are relevant for our understanding of evolution and the dynamics of mammalian nervous systems in response to environmental changes.
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Affiliation(s)
- Javier Lázaro
- Max Planck Institute for Ornithology, Department of Migration and Immuno-Ecology, 78315 Radolfzell, Germany .,University of Konstanz, Department of Biology, 78457 Konstanz, Germany
| | - Moritz Hertel
- Max Planck Institute for Ornithology, Department of Behavioural Neurobiology, 82319 Seewiesen, Germany
| | - Scott LaPoint
- Max Planck Institute for Ornithology, Department of Migration and Immuno-Ecology, 78315 Radolfzell, Germany.,Lamont-Doherty Earth Observatory, Columbia University, Department of Earth and Environmental Sciences, Palisades, New York 10964, USA
| | - Martin Wikelski
- Max Planck Institute for Ornithology, Department of Migration and Immuno-Ecology, 78315 Radolfzell, Germany.,University of Konstanz, Department of Biology, 78457 Konstanz, Germany
| | - Matthias Stiehler
- University of Konstanz, Department of Biology, 78457 Konstanz, Germany
| | - Dina K N Dechmann
- Max Planck Institute for Ornithology, Department of Migration and Immuno-Ecology, 78315 Radolfzell, Germany.,University of Konstanz, Department of Biology, 78457 Konstanz, Germany
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Dullin C, Ufartes R, Larsson E, Martin S, Lazzarini M, Tromba G, Missbach-Guentner J, Pinkert-Leetsch D, Katschinski DM, Alves F. μCT of ex-vivo stained mouse hearts and embryos enables a precise match between 3D virtual histology, classical histology and immunochemistry. PLoS One 2017; 12:e0170597. [PMID: 28178293 PMCID: PMC5298245 DOI: 10.1371/journal.pone.0170597] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/06/2017] [Indexed: 12/13/2022] Open
Abstract
The small size of the adult and developing mouse heart poses a great challenge for imaging in preclinical research. The aim of the study was to establish a phosphotungstic acid (PTA) ex-vivo staining approach that efficiently enhances the x-ray attenuation of soft-tissue to allow high resolution 3D visualization of mouse hearts by synchrotron radiation based μCT (SRμCT) and classical μCT. We demonstrate that SRμCT of PTA stained mouse hearts ex-vivo allows imaging of the cardiac atrium, ventricles, myocardium especially its fibre structure and vessel walls in great detail and furthermore enables the depiction of growth and anatomical changes during distinct developmental stages of hearts in mouse embryos. Our x-ray based virtual histology approach is not limited to SRμCT as it does not require monochromatic and/or coherent x-ray sources and even more importantly can be combined with conventional histological procedures. Furthermore, it permits volumetric measurements as we show for the assessment of the plaque volumes in the aortic valve region of mice from an ApoE-/- mouse model. Subsequent, Masson-Goldner trichrome staining of paraffin sections of PTA stained samples revealed intact collagen and muscle fibres and positive staining of CD31 on endothelial cells by immunohistochemistry illustrates that our approach does not prevent immunochemistry analysis. The feasibility to scan hearts already embedded in paraffin ensured a 100% correlation between virtual cut sections of the CT data sets and histological heart sections of the same sample and may allow in future guiding the cutting process to specific regions of interest. In summary, since our CT based virtual histology approach is a powerful tool for the 3D depiction of morphological alterations in hearts and embryos in high resolution and can be combined with classical histological analysis it may be used in preclinical research to unravel structural alterations of various heart diseases.
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Affiliation(s)
- Christian Dullin
- Institute for Diagnostic and Interventional Radiology, University Medical Center, Goettingen, Germany
- Synchrotron Light Source ‘Elettra,’ Trieste, Italy
- * E-mail:
| | - Roser Ufartes
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | | | - Sabine Martin
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Goettingen, Germany
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Goettingen, Germany
| | - Marcio Lazzarini
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | | | - Jeannine Missbach-Guentner
- Institute for Diagnostic and Interventional Radiology, University Medical Center, Goettingen, Germany
- Clinic for Haematology and Medical Oncology, University Medical Center, Goettingen, Germany
| | - Diana Pinkert-Leetsch
- Clinic for Haematology and Medical Oncology, University Medical Center, Goettingen, Germany
| | - Dörthe M. Katschinski
- Institute of Cardiovascular Physiology, University Medical Center, Goettingen, Germany
| | - Frauke Alves
- Institute for Diagnostic and Interventional Radiology, University Medical Center, Goettingen, Germany
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Goettingen, Germany
- Clinic for Haematology and Medical Oncology, University Medical Center, Goettingen, Germany
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