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Dwivedi R, Kaushik M, Tripathi M, Dada R, Tiwari P. Unraveling the genetic basis of epilepsy: Recent advances and implications for diagnosis and treatment. Brain Res 2024; 1843:149120. [PMID: 39032529 DOI: 10.1016/j.brainres.2024.149120] [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: 05/20/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/23/2024]
Abstract
Epilepsy, affecting approximately 1% of the global population, manifests as recurring seizures and is heavily influenced by genetic factors. Recent advancements in genetic technologies have revolutionized our understanding of epilepsy's genetic landscape. Key studies, such as the discovery of mutations in ion channels (e.g., SCN1A and SCN2A), neurotransmitter receptors (e.g., GABRA1), and synaptic proteins (e.g., SYNGAP1, KCNQ2), have illuminated critical pathways underlying epilepsy susceptibility and pathogenesis. Genome-wide association studies (GWAS) have identified specific genetic variations linked to epilepsy risk, such as variants near SCN1A and PCDH7, enhancing diagnostic accuracy and enabling personalized treatment strategies. Moreover, epigenetic mechanisms, including DNA methylation (e.g., MBD5), histone modifications (e.g., HDACs), and non-coding RNAs (e.g., miR-134), play pivotal roles in altering gene expression and synaptic plasticity, contributing to epileptogenesis. These discoveries offer promising avenues for therapeutic interventions aimed at improving outcomes for epilepsy patients. Genetic testing has become essential in clinical practice, facilitating precise diagnosis and tailored management approaches based on individual genetic profiles. Furthermore, insights into epigenetic regulation suggest novel therapeutic targets for developing more effective epilepsy treatments. In summary, this review highlights significant progress in understanding the genetic and epigenetic foundations of epilepsy. By integrating findings from key studies and specifying genes involved in epigenetic modifications, we underscore the potential for advanced therapeutic strategies in this complex neurological disorder, emphasizing the importance of personalized medicine approaches in epilepsy management.
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Affiliation(s)
- Rekha Dwivedi
- Department of Neurology, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Meenakshi Kaushik
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Manjari Tripathi
- Department of Neurology, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Rima Dada
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Prabhakar Tiwari
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India.
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2
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Iyer SH, Hinman JE, Warren T, Matthews SA, Simeone TA, Simeone KA. Altered ventilatory responses to hypercapnia-hypoxia challenges in a preclinical SUDEP model involve orexin neurons. Neurobiol Dis 2024; 199:106592. [PMID: 38971479 DOI: 10.1016/j.nbd.2024.106592] [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: 12/22/2023] [Revised: 06/25/2024] [Accepted: 07/02/2024] [Indexed: 07/08/2024] Open
Abstract
Failure to recover from repeated hypercapnia and hypoxemia (HH) challenges caused by severe GCS and postictal apneas may contribute to sudden unexpected death in epilepsy (SUDEP). Our previous studies found orexinergic dysfunction contributes to respiratory abnormalities in a preclinical model of SUDEP, Kcna1-/- mice. Here, we developed two gas challenges consisting of repeated HH exposures and used whole body plethysmography to determine whether Kcna1-/- mice have detrimental ventilatory responses. Kcna1-/- mice exhibited an elevated ventilatory response to a mild repeated hypercapnia-hypoxia (HH) challenge compared to WT. Moreover, 71% of Kcna1-/- mice failed to survive a severe repeated HH challenge, whereas all WT mice recovered. We next determined whether orexin was involved in these differences. Pretreating Kcna1-/- mice with a dual orexin receptor antagonist rescued the ventilatory response during the mild challenge and all subjects survived the severe challenge. In ex vivo extracellular recordings in the lateral hypothalamus of coronal brain slices, we found reducing pH either inhibits or stimulates putative orexin neurons similar to other chemosensitive neurons; however, a significantly greater percentage of putative orexin neurons from Kcna1-/-mice were stimulated and the magnitude of stimulation was increased resulting in augmentation of the calculated chemosensitivity index relative to WT. Collectively, our data suggest that increased chemosensitive activity of orexin neurons may be pathologic in the Kcna1-/- mouse model of SUDEP, and contribute to elevated ventilatory responses. Our preclinical data suggest that those at high risk for SUDEP may be more sensitive to HH challenges, whether induced by seizures or other means; and the depth and length of the HH exposure could dictate the probability of survival.
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Affiliation(s)
- Shruthi H Iyer
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Jillian E Hinman
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Ted Warren
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Stephanie A Matthews
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Timothy A Simeone
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Kristina A Simeone
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA.
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Gu J, Shao W, Liu L, Wang Y, Yang Y, Zhang Z, Wu Y, Xu Q, Gu L, Zhang Y, Shen Y, Zhao H, Zeng C, Zhang H. Challenges and future directions of SUDEP models. Lab Anim (NY) 2024; 53:226-243. [PMID: 39187733 DOI: 10.1038/s41684-024-01426-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 08/02/2024] [Indexed: 08/28/2024]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among patients with epilepsy, causing a global public health burden. The underlying mechanisms of SUDEP remain elusive, and effective prevention or treatment strategies require further investigation. A major challenge in current SUDEP research is the lack of an ideal model that maximally mimics the human condition. Animal models are important for revealing the potential pathogenesis of SUDEP and preventing its occurrence; however, they have potential limitations due to species differences that prevent them from precisely replicating the intricate physiological and pathological processes of human disease. This Review provides a comprehensive overview of several available SUDEP animal models, highlighting their pros and cons. More importantly, we further propose the establishment of an ideal model based on brain-computer interfaces and artificial intelligence, hoping to offer new insights into potential advancements in SUDEP research. In doing so, we hope to provide valuable information for SUDEP researchers, offer new insights into the pathogenesis of SUDEP and open new avenues for the development of strategies to prevent SUDEP.
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Affiliation(s)
- JiaXuan Gu
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - WeiHui Shao
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Lu Liu
- Department of Anesthesiology, Zhejiang University School of Medicine, Hangzhou, China
| | - YuLing Wang
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yue Yang
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - ZhuoYue Zhang
- Department of Anesthesiology, Zhejiang University School of Medicine, Hangzhou, China
| | - YaXuan Wu
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Qing Xu
- Department of Anesthesiology, Zhejiang University School of Medicine, Hangzhou, China
| | - LeYuan Gu
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - YuanLi Zhang
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yue Shen
- Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Westlake University School of Medicine, Hangzhou, China
| | - HaiTing Zhao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Chang Zeng
- Health Management Center, Xiangya Hospital, Central South University, Changsha, China
| | - HongHai Zhang
- Department of Anesthesiology, the Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, China.
- Department of Anesthesiology, Zhejiang University School of Medicine, Hangzhou, China.
- Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Westlake University School of Medicine, Hangzhou, China.
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Baylie T, Ayelgn T, Tiruneh M, Tesfa KH. Effect of Ketogenic Diet on Obesity and Other Metabolic Disorders: Narrative Review. Diabetes Metab Syndr Obes 2024; 17:1391-1401. [PMID: 38529169 PMCID: PMC10962461 DOI: 10.2147/dmso.s447659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 03/06/2024] [Indexed: 03/27/2024] Open
Abstract
Obesity is defined as an abnormal or excessive accumulation of fat that increases the burden of different chronic diseases in the population. It has reached epidemic proportions and is a major risk factor for a variety of diseases, including hypertension, cardiovascular disease, type 2 diabetes, dyslipidaemia, atherosclerosis, and some malignancies. Weight gain is a result of excessive energy intake compared to energy expenditure (energy loss from metabolism and physical exercise). A ketogenic diet has a more useful effect on obesity than other diets. A ketogenic diet is a low-carbohydrate, high-fat, moderate-protein diet that induces the production of ketone bodies by mimicking the breakdown of a fasting state. The mechanism behind the ketogenic diet is still unknown, although it obviously helps people with obesity lose weight. Several pathways for the ketogenic diet effect on weight loss have been hypothesized by researchers, including reduced appetite due to effects on appetite control hormones and a possible direct appetite suppressant action of ketone bodies; reduced lipogenesis and increased lipolysis; greater metabolic efficiency; and increased metabolic costs.
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Affiliation(s)
- Temesgen Baylie
- Department of Biomedical Science, School of Medicine, Debre Markos University, Debre Markos, Ethiopia
| | - Tiget Ayelgn
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Markeshaw Tiruneh
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Kibur Hunie Tesfa
- Department of Biochemistry, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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Simeone T, Simeone K. The Unconventional Effects of the Ketogenic Diet (KD) in Preclinical Epilepsy. Epilepsy Curr 2024; 24:117-122. [PMID: 39280056 PMCID: PMC11394414 DOI: 10.1177/15357597231216916] [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: 09/18/2024] Open
Abstract
The integration of metabolic therapeutics in the available clinical armory is becoming more commonplace in health care as our understanding about the dependence of disease on metabolism continues to deepen and evolve. In the epilepsy field, we often think about the ketogenic diet (KD, high fat: carbohydrate ratio) in terms of its anti-seizure efficacy. The aim of this article is to review what we've learned from preclinical studies about the KD's more unconventional effects, including its neuroprotective effects, anti-epileptogenic and disease-modifying effects, and how the KD influences comorbidities associated with epilepsy. As time moves us into the future and metabolic therapies become more common place, the effects of the KD considered unconventional herein, may end up being referred to as traditional.
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Affiliation(s)
- Timothy Simeone
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Kristina Simeone
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
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Iyer SH, Yeh MY, Netzel L, Lindsey MG, Wallace M, Simeone KA, Simeone TA. Dietary and Metabolic Approaches for Treating Autism Spectrum Disorders, Affective Disorders and Cognitive Impairment Comorbid with Epilepsy: A Review of Clinical and Preclinical Evidence. Nutrients 2024; 16:553. [PMID: 38398876 PMCID: PMC10893388 DOI: 10.3390/nu16040553] [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: 12/24/2023] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 02/25/2024] Open
Abstract
Epilepsy often occurs with other neurological disorders, such as autism, affective disorders, and cognitive impairment. Research indicates that many neurological disorders share a common pathophysiology of dysfunctional energy metabolism, neuroinflammation, oxidative stress, and gut dysbiosis. The past decade has witnessed a growing interest in the use of metabolic therapies for these disorders with or without the context of epilepsy. Over one hundred years ago, the high-fat, low-carbohydrate ketogenic diet (KD) was formulated as a treatment for epilepsy. For those who cannot tolerate the KD, other diets have been developed to provide similar seizure control, presumably through similar mechanisms. These include, but are not limited to, the medium-chain triglyceride diet, low glycemic index diet, and calorie restriction. In addition, dietary supplementation with ketone bodies, polyunsaturated fatty acids, or triheptanoin may also be beneficial. The proposed mechanisms through which these diets and supplements work to reduce neuronal hyperexcitability involve normalization of aberrant energy metabolism, dampening of inflammation, promotion of endogenous antioxidants, and reduction of gut dysbiosis. This raises the possibility that these dietary and metabolic therapies may not only exert anti-seizure effects, but also reduce comorbid disorders in people with epilepsy. Here, we explore this possibility and review the clinical and preclinical evidence where available.
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Affiliation(s)
| | | | | | | | | | | | - Timothy A. Simeone
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA; (S.H.I.); (K.A.S.)
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Kodirov SA. Adam, amigo, brain, and K channel. Biophys Rev 2023; 15:1393-1424. [PMID: 37975011 PMCID: PMC10643815 DOI: 10.1007/s12551-023-01163-5] [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: 05/02/2023] [Accepted: 09/28/2023] [Indexed: 11/19/2023] Open
Abstract
Voltage-dependent K+ (Kv) channels are diverse, comprising the classical Shab - Kv2, Shaker - Kv1, Shal - Kv4, and Shaw - Kv3 families. The Shaker family alone consists of Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5, Kv1.6, and Kv1.7. Moreover, the Shab family comprises two functional (Kv2.1 and Kv2.2) and several "silent" alpha subunits (Kv2.3, Kv5, Kv6, Kv8, and Kv9), which do not generate K current. However, e.g., Kv8.1, via heteromerization, inhibits outward currents of the same family or even that of Shaw. This property of Kv8.1 is similar to those of designated beta subunits or non-selective auxiliary elements, including ADAM or AMIGO proteins. Kv channels and, in turn, ADAM may modulate the synaptic long-term potentiation (LTP). Prevailingly, Kv1.1 and Kv1.5 are attributed to respective brain and heart pathologies, some of which may occur simultaneously. The aforementioned channel proteins are apparently involved in several brain pathologies, including schizophrenia and seizures.
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Affiliation(s)
- Sodikdjon A. Kodirov
- Department of Biological Sciences, University of Texas at Brownsville, Brownsville, TX 78520 USA
- Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, Russia
- Instituto de Medicina Molecular, Universidade de Lisboa, 1649-028 Lisbon, Portugal
- Almazov Federal Heart, Blood and Endocrinology Centre, Saint Petersburg, 197341 Russia
- Institute for Physiology and Pathophysiology, Johannes Kepler University, Linz, Austria
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Berteotti C, Calvello C, Liguori C. Role of the orexin system in the bidirectional relation between sleep and epilepsy: New chances for patients with epilepsy by the antagonism to orexin receptors? Epilepsia 2023; 64:1991-2005. [PMID: 37212716 DOI: 10.1111/epi.17661] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 05/19/2023] [Accepted: 05/19/2023] [Indexed: 05/23/2023]
Abstract
Epilepsy is a common neurological disorder, affecting patients of all ages, reducing the quality of life, and associated with several comorbidities. Sleep impairment is a frequent condition in patients with epilepsy (PWE), and the relation between sleep and epilepsy has been considered bidirectional, as one can significantly influence the other, and vice versa. The orexin system was described more than 20 years ago and is implicated in several neurobiological functions other than in controlling the sleep-wake cycle. Considering the relation between epilepsy and sleep, and the significant contribution of the orexin system in regulating the sleep-wake cycle, it is conceivable that the orexin system may be affected in PWE. Preclinical studies investigated the impact of the orexin system on epileptogenesis and the effect of orexin antagonism on seizures in animal models. Conversely, clinical studies are few and propose heterogeneous results also considering the different methodological approaches to orexin levels quantification (cerebrospinal-fluid or blood samples). Because orexin system activity can be modulated by sleep, and considering the sleep impairment documented in PWE, the recently approved dual orexin receptor antagonists (DORAs) have been suggested for treating sleep impairment and insomnia in PWE. Accordingly, sleep improvement can be a therapeutic strategy for reducing seizures and better managing epilepsy. The present review analyzes the preclinical and clinical evidence linking the orexin system to epilepsy, and hypothesizes a model in which the antagonism to the orexin system by DORAs can improve epilepsy by both a direct and a sleep-mediated (indirect) effect.
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Affiliation(s)
- Chiara Berteotti
- Physiological Regulation in Sleeping Mice Lab, Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Carmen Calvello
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Claudio Liguori
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
- Epilepsy Center, Neurology Unit, University Hospital Tor Vergata, Rome, Italy
- Sleep Medicine Center, Neurology Unit, University Hospital Tor Vergata, Rome, Italy
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Zhang LM, Chen L, Zhao YF, Duan WM, Zhong LM, Liu MW. Identification of key potassium channel genes of temporal lobe epilepsy by bioinformatics analyses and experimental verification. Front Neurol 2023; 14:1175007. [PMID: 37483435 PMCID: PMC10361730 DOI: 10.3389/fneur.2023.1175007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/16/2023] [Indexed: 07/25/2023] Open
Abstract
One of the most prevalent types of epilepsy is temporal lobe epilepsy (TLE), which has unknown etiological factors and drug resistance. The detailed mechanisms underlying potassium channels in human TLE have not yet been elucidated. Hence, this study aimed to mine potassium channel genes linked to TLE using a bioinformatic approach. The results found that Four key TLE-related potassium channel genes (TERKPCGs) were identified: potassium voltage-gated channel subfamily E member (KCNA) 1, KCNA2, potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11), and KCNS1. A protein-protein interaction (PPI) network was constructed to analyze the relationship between TERKPCGs and other key module genes. The results of gene set enrichment analysis (GSEA) for a single gene indicated that the four TERKPCGs were highly linked to the cation channel, potassium channel, respiratory chain, and oxidative phosphorylation. The mRNA-TF network was established using four mRNAs and 113 predicted transcription factors. A ceRNA network containing seven miRNAs, two mRNAs, and 244 lncRNAs was constructed based on the TERKPCGs. Three common small-molecule drugs (enflurane, promethazine, and miconazole) target KCNA1, KCNA2, and KCNS1. Ten small-molecule drugs (glimepiride, diazoxide, levosimendan, and thiamylal et al.) were retrieved for KCNJ11. Compared to normal mice, the expression of KCNA1, KCNA2, KCNJ11, and KCNS1 was downregulated in the brain tissue of the epilepsy mouse model at both the transcriptional and translational levels, which was consistent with the trend of human data from the public database. The results indicated that key potassium channel genes linked to TLE were identified based on bioinformatics analysis to investigate the potential significance of potassium channel genes in the development and treatment of TLE.
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Affiliation(s)
- Lin-ming Zhang
- Department of Neurology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
- Yunnan Provincial Clinical Research Center for Neurological Disease, Kunming, Yunnan, China
| | - Ling Chen
- Department of Neurology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
- Yunnan Provincial Clinical Research Center for Neurological Disease, Kunming, Yunnan, China
| | - Yi-fei Zhao
- Department of Neurology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
- Yunnan Provincial Clinical Research Center for Neurological Disease, Kunming, Yunnan, China
| | - Wei-mei Duan
- Department of Neurology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
- Yunnan Provincial Clinical Research Center for Neurological Disease, Kunming, Yunnan, China
| | - Lian-mei Zhong
- Department of Neurology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
- Yunnan Provincial Clinical Research Center for Neurological Disease, Kunming, Yunnan, China
| | - Ming-wei Liu
- Department of Emergency, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
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Paulhus K, Glasscock E. Novel Genetic Variants Expand the Functional, Molecular, and Pathological Diversity of KCNA1 Channelopathy. Int J Mol Sci 2023; 24:8826. [PMID: 37240170 PMCID: PMC10219020 DOI: 10.3390/ijms24108826] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/11/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
The KCNA1 gene encodes Kv1.1 voltage-gated potassium channel α subunits, which are crucial for maintaining healthy neuronal firing and preventing hyperexcitability. Mutations in the KCNA1 gene can cause several neurological diseases and symptoms, such as episodic ataxia type 1 (EA1) and epilepsy, which may occur alone or in combination, making it challenging to establish simple genotype-phenotype correlations. Previous analyses of human KCNA1 variants have shown that epilepsy-linked mutations tend to cluster in regions critical for the channel's pore, whereas EA1-associated mutations are evenly distributed across the length of the protein. In this review, we examine 17 recently discovered pathogenic or likely pathogenic KCNA1 variants to gain new insights into the molecular genetic basis of KCNA1 channelopathy. We provide the first systematic breakdown of disease rates for KCNA1 variants in different protein domains, uncovering potential location biases that influence genotype-phenotype correlations. Our examination of the new mutations strengthens the proposed link between the pore region and epilepsy and reveals new connections between epilepsy-related variants, genetic modifiers, and respiratory dysfunction. Additionally, the new variants include the first two gain-of-function mutations ever discovered for KCNA1, the first frameshift mutation, and the first mutations located in the cytoplasmic N-terminal domain, broadening the functional and molecular scope of KCNA1 channelopathy. Moreover, the recently identified variants highlight emerging links between KCNA1 and musculoskeletal abnormalities and nystagmus, conditions not typically associated with KCNA1. These findings improve our understanding of KCNA1 channelopathy and promise to enhance personalized diagnosis and treatment for individuals with KCNA1-linked disorders.
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Affiliation(s)
| | - Edward Glasscock
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, USA;
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George AG, Farrell JS, Colangeli R, Wall AK, Gom RC, Kesler MT, Rodriguez de la Hoz C, Villa BR, Perera T, Rho JM, Kurrasch D, Teskey GC. Sudden unexpected death in epilepsy is prevented by blocking postictal hypoxia. Neuropharmacology 2023; 231:109513. [PMID: 36948357 DOI: 10.1016/j.neuropharm.2023.109513] [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: 10/19/2022] [Revised: 02/21/2023] [Accepted: 03/18/2023] [Indexed: 03/24/2023]
Abstract
Epilepsy is at times a fatal disease. Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related mortality in people with intractable epilepsy and is defined by exclusion; non-accidental, non-toxicologic, and non-anatomic causes of death. While SUDEP often follows a bilateral tonic-clonic seizure, the mechanisms that ultimately lead to terminal apnea and then asystole remain elusive and there is a lack of preventative treatments. Based on the observation that discrete seizures lead to local and postictal vasoconstriction, resulting in hypoperfusion, hypoxia and behavioural disturbances in the forebrain we reasoned those similar mechanisms may play a role in SUDEP when seizures invade the brainstem. Here we tested this neurovascular-based hypothesis of SUDEP in awake non-anesthetized mice by pharmacologically preventing seizure-induced vasoconstriction, with cyclooxygenase-2 or L-type calcium channel antagonists. In both acute and chronic mouse models of seizure-induced premature mortality, ibuprofen and nicardipine extended life while systemic drug levels remained high enough to be effective. We also examined the potential role of spreading depolarization in the acute model of seizure-induced premature mortality. These data provide a proof-of-principle for the neurovascular hypothesis of SUDEP rather than spreading depolarization and the use of currently available drugs to prevent it.
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Affiliation(s)
- Antis G George
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Jordan S Farrell
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Neurosurgery, Stanford University, Palo Alto, CA, 94305, USA
| | - Roberto Colangeli
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada; Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Alexandra K Wall
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Renaud C Gom
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Mitchell T Kesler
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | | | - Bianca R Villa
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Tefani Perera
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Jong M Rho
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Neurosciences, Pediatrics and Pharmacology, University of California, San Diego and Rady Children's Hospital, San Diego, CA, USA
| | - Deborah Kurrasch
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - G Campbell Teskey
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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12
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Yu C, Deng XJ, Xu D. Gene mutations in comorbidity of epilepsy and arrhythmia. J Neurol 2023; 270:1229-1248. [PMID: 36376730 DOI: 10.1007/s00415-022-11430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022]
Abstract
Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China.
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13
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Teran FA, Bravo E, Richerson GB. Sudden unexpected death in epilepsy: Respiratory mechanisms. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:153-176. [PMID: 36031303 PMCID: PMC10191258 DOI: 10.1016/b978-0-323-91532-8.00012-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Epilepsy is one of the most common chronic neurologic diseases, with a prevalence of 1% in the US population. Many people with epilepsy live normal lives, but are at risk of sudden unexpected death in epilepsy (SUDEP). This mysterious comorbidity of epilepsy causes premature death in 17%-50% of those with epilepsy. Most SUDEP occurs after a generalized seizure, and patients are typically found in bed in the prone position. Until recently, it was thought that SUDEP was due to cardiovascular failure, but patients who died while being monitored in hospital epilepsy units revealed that most SUDEP is due to postictal central apnea. Some cases may occur when seizures invade the amygdala and activate projections to the brainstem. Evidence suggests that the pathophysiology is linked to defects in the serotonin system and central CO2 chemoreception, and that there is considerable overlap with mechanisms thought to be involved in sudden infant death syndrome (SIDS). Future work is needed to identify biomarkers for patients at highest risk, improve ascertainment, develop methods to alert caregivers when SUDEP is imminent, and find effective approaches to prevent these fatal events.
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Affiliation(s)
- Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States.
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA, United States
| | - George B Richerson
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA, United States
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Deodhar M, Matthews SA, Thomas B, Adamian L, Mattes S, Wells T, Zieba B, Simeone KA, Simeone TA. Pharmacoresponsiveness of spontaneous recurrent seizures and the comorbid sleep disorder of epileptic Kcna1-null mice. Eur J Pharmacol 2021; 913:174656. [PMID: 34838797 DOI: 10.1016/j.ejphar.2021.174656] [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: 08/18/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 11/24/2022]
Abstract
Drug resistant epilepsy affects ∼30% of people with epilepsy and is associated with epilepsy syndromes with frequent and multiple types of seizures, lesions or cytoarchitectural abnormalities, increased risk of mortality and comorbidities such as cognitive impairment and sleep disorders. A limitation of current preclinical models is that spontaneous seizures with comorbidities take time to induce and test, thus making them low-throughput. Kcna1-null mice exhibit all the characteristics of drug resistant epilepsy with spontaneous seizures and comorbidities occurring naturally; thus, we aimed to determine whether they also demonstrate pharmacoresistanct seizures and the impact of medications on their sleep disorder comorbidity. In this exploratory study, Kcna1-null mice were treated with one of four conventional antiseizure medications, carbamazepine, levetiracetam, phenytoin, and phenobarbital using a moderate throughput protocol (vehicle for 2 days followed by 2 days of treatment with high therapeutic doses selected based on published data in the 6 Hz model of pharmacoresistant seizures). Spontaneous recurrent seizures and vigilance states were recorded with video-EEG/EMG. Carbamazepine, levetiracetam and phenytoin had partial efficacy (67%, 75% and 33% were seizure free, respectively), whereas phenobarbital was fully efficacious and conferred seizure freedom to all mice. Thus, seizures of Kcna1-null mice appear to be resistant to three of the drugs tested. Levetiracetam failed to affect sleep architecture, carbamazepine and phenytoin had moderate effects, and phenobarbital, as predicted, restored sleep architecture. Data suggest Kcna1-null mice may be a moderate throughput model of drug resistant epilepsy useful in determining mechanisms of pharmacoresistance and testing novel therapeutic strategies.
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Affiliation(s)
- Malavika Deodhar
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Stephanie A Matthews
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Brittany Thomas
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Leena Adamian
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Sarah Mattes
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Tabitha Wells
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Brianna Zieba
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Kristina A Simeone
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Timothy A Simeone
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE, USA.
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15
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Crotts MS, Kim Y, Bravo E, Richerson GB, Teran FA. A ketogenic diet protects DBA/1 and Scn1a R1407X/+ mice against seizure-induced respiratory arrest independent of ketosis. Epilepsy Behav 2021; 124:108334. [PMID: 34600281 PMCID: PMC8960470 DOI: 10.1016/j.yebeh.2021.108334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/02/2021] [Accepted: 09/07/2021] [Indexed: 10/20/2022]
Abstract
Patients with uncontrolled epilepsy have a high risk of sudden unexpected death in epilepsy (SUDEP). Seizure-induced respiratory arrest (S-IRA) is thought to be the determining cause of death in many cases of SUDEP. The goal of the present study was to use Scn1aR1407X/+ (Dravet Syndrome, DS) and DBA/1 mice to determine: (1) the effect of a ketogenic diet (KD) on S-IRA and (2) the relationship between serum ketones and the protective effect of a KD. Ketogenic diet treatment significantly decreased spontaneous seizure-induced mortality in DS mice compared to control (8% vs 39%, p = 0.0021). This protective effect was not abolished when ketosis was prevented by supplementing the KD with glucose (10% mortality, p = 0.0007). In DBA/1 mice, the latency to onset of S-IRA due to audiogenic seizures was delayed from 7.6 to 20.8 seconds by a KD on treatment day (TD) 7 compared to control (p < 0.0001), an effect that was reversed on TD14 when mice were crossed over to a control diet on TD7. β-Hydroxybutyrate (BHB) levels were significantly decreased in DBA/1 mice on a KD supplemented with glucose (p = 0.0038), but the protective effect was maintained. Our findings show that a KD decreases SUDEP in DS mice and increases the latency to audiogenic S-IRA in DBA/1 mice. In both mouse models, a KD was protective against S-IRA. This effect may be due in part to specific dietary components rather than generation of ketone bodies.
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Affiliation(s)
- Megan S Crotts
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, United States
| | - YuJaung Kim
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States
| | - George B Richerson
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, United States; Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA 52242, United States; Neurology, Veterans Affairs Medical Center, Iowa City, IA 52242, United States
| | - Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, United States; Medical Scientist Training Program, University of Iowa, Iowa City, IA 52242, United States.
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16
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Calcaterra V, Verduci E, Pascuzzi MC, Magenes VC, Fiore G, Di Profio E, Tenuta E, Bosetti A, Todisco CF, D'Auria E, Zuccotti G. Metabolic Derangement in Pediatric Patient with Obesity: The Role of Ketogenic Diet as Therapeutic Tool. Nutrients 2021; 13:2805. [PMID: 34444964 PMCID: PMC8400548 DOI: 10.3390/nu13082805] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/22/2021] [Accepted: 08/12/2021] [Indexed: 12/11/2022] Open
Abstract
Obesity is defined as a condition characterized by an excessive fat accumulation that has negative health consequences. Pediatric obesity is associated with an increased risk for many diseases, including impaired glycemic and lipidic control that may lead to the development of chronic, and potentially disabling, pathologies, such as type 2 diabetes mellitus (T2DM) and cardiovascular events, in adult life. The therapeutic strategy initially starts with interventions that are aimed at changing lifestyle and eating behavior, to prevent, manage, and potentially reverse metabolic disorders. Recently, the ketogenic diet (KD) has been proposed as a promising dietary intervention for the treatment of metabolic and cardiovascular risk factors related to obesity in adults, and a possible beneficial role has also been proposed in children. KD is very low in carbohydrate, high in fat, and moderate to high in protein that may have the potential to promote weight loss and improve lipidic derangement, glycemic control, and insulin sensitivity. In this review, we present metabolic disorders on glycemic and lipidic control in children and adolescents with obesity and indication of KD in pediatrics, discussing the role of KD as a therapeutic tool for metabolic derangement. The results of this review may suggest the validity of KD and the need to further research its potential to address metabolic risk factors in pediatric obesity.
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Affiliation(s)
- Valeria Calcaterra
- Pediatric and Adolescent Unit, Department of Internal Medicine, University of Pavia, 27100 Pavia, Italy
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
| | - Elvira Verduci
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Health Sciences, University of Milano, 20142 Milano, Italy
| | - Martina Chiara Pascuzzi
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Biomedical and Clinical Science "L. Sacco", University of Milan, 20157 Milan, Italy
| | - Vittoria Carlotta Magenes
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Biomedical and Clinical Science "L. Sacco", University of Milan, 20157 Milan, Italy
| | - Giulia Fiore
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Health Sciences, University of Milano, 20142 Milano, Italy
| | - Elisabetta Di Profio
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Biomedical and Clinical Science "L. Sacco", University of Milan, 20157 Milan, Italy
| | - Elisavietta Tenuta
- Pediatric and Adolescent Unit, Department of Internal Medicine, University of Pavia, 27100 Pavia, Italy
| | - Alessandra Bosetti
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
| | - Carolina Federica Todisco
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Biomedical and Clinical Science "L. Sacco", University of Milan, 20157 Milan, Italy
| | - Enza D'Auria
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Biomedical and Clinical Science "L. Sacco", University of Milan, 20157 Milan, Italy
| | - Gianvincenzo Zuccotti
- Pediatric Department, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy
- Department of Biomedical and Clinical Science "L. Sacco", University of Milan, 20157 Milan, Italy
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17
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Simeone KA, Wilke JC, Matthews SA, Simeone TA, Rho JM. Ketogenic diet-mediated seizure reduction preserves CA1 cell numbers in epileptic Kcna1-null mice: An unbiased stereological assessment. Epilepsia 2021; 62:e123-e128. [PMID: 34231878 DOI: 10.1111/epi.16983] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 10/20/2022]
Abstract
There is growing evidence for the disease-modifying potential of metabolic therapies, including the ketogenic diet (KD), which is used to treat medically intractable epilepsy. However, it remains unclear whether the KD exerts direct effects on histopathological changes in epileptic brain, or whether the changes are a consequence of diet-induced reduction in seizure activity. Here, we used unbiased stereological techniques to quantify the seizure-induced reduction in cell number in the CA1 region of the hippocampus of epileptic Kcna1-null mice and compared the effects of the KD with that of phenobarbital (PB), a widely employed anti-seizure drug. Our data suggest that the anti-seizure activity of the KD or PB was similar. However, CA1 cell numbers of KD-treated hippocampi were not significantly different from those seen in wild-type (WT) mice, whereas CA1 cell counts in standard diet and PB-treated Kcna1-null mice were 23% and 31% lower than WT animals, respectively. These results support the notion that structural protection of cells may involve more than seizure attenuation, and that the KD engages mechanisms that also promote or restore hippocampal morphological integrity.
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Affiliation(s)
- Kristina A Simeone
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Julianne C Wilke
- Department of Pediatrics, University of California San Diego, San Diego, CA, USA.,Rady Children's Hospital San Diego, San Diego, CA, USA
| | - Stephanie A Matthews
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Timothy A Simeone
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, USA
| | - Jong M Rho
- Department of Pediatrics, University of California San Diego, San Diego, CA, USA.,Rady Children's Hospital San Diego, San Diego, CA, USA.,Department of Neurosciences, University of California San Diego, San Diego, CA, USA
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18
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Ketogenic diets and the nervous system: a scoping review of neurological outcomes from nutritional ketosis in animal studies. Nutr Res Rev 2021; 35:268-281. [PMID: 34180385 DOI: 10.1017/s0954422421000214] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Ketogenic diets have reported efficacy for neurological dysfunctions; however, there are limited published human clinical trials elucidating the mechanisms by which nutritional ketosis produces therapeutic effects. The purpose of this present study was to investigate animal models that report variations in nervous system function by changing from a standard animal diet to a ketogenic diet, synthesise these into broad themes, and compare these with mechanisms reported as targets in pain neuroscience to inform human chronic pain trials. METHODS An electronic search of seven databases was conducted in July 2020. Two independent reviewers screened studies for eligibility, and descriptive outcomes relating to nervous system function were extracted for a thematic analysis, then synthesised into broad themes. RESULTS In total, 170 studies from eighteen different disease models were identified and grouped into fourteen broad themes: alterations in cellular energetics and metabolism, biochemical, cortical excitability, epigenetic regulation, mitochondrial function, neuroinflammation, neuroplasticity, neuroprotection, neurotransmitter function, nociception, redox balance, signalling pathways, synaptic transmission and vascular supply. DISCUSSION The mechanisms presented centred around the reduction of inflammation and oxidative stress as well as a reduction in nervous system excitability. Given the multiple potential mechanisms presented, it is likely that many of these are involved synergistically and undergo adaptive processes within the human body, and controlled animal models that limit the investigation to a particular pathway in isolation may reach differing conclusions. Attention is required when translating this information to human chronic pain populations owing to the limitations outlined from the animal research.
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19
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Kovács Z, Brunner B, Ari C. Beneficial Effects of Exogenous Ketogenic Supplements on Aging Processes and Age-Related Neurodegenerative Diseases. Nutrients 2021; 13:nu13072197. [PMID: 34206738 PMCID: PMC8308443 DOI: 10.3390/nu13072197] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
Life expectancy of humans has increased continuously up to the present days, but their health status (healthspan) was not enhanced by similar extent. To decrease enormous medical, economical and psychological burden that arise from this discrepancy, improvement of healthspan is needed that leads to delaying both aging processes and development of age-related diseases, thereby extending lifespan. Thus, development of new therapeutic tools to alleviate aging processes and related diseases and to increase life expectancy is a topic of increasing interest. It is widely accepted that ketosis (increased blood ketone body levels, e.g., β-hydroxybutyrate) can generate neuroprotective effects. Ketosis-evoked neuroprotective effects may lead to improvement in health status and delay both aging and the development of related diseases through improving mitochondrial function, antioxidant and anti-inflammatory effects, histone and non-histone acetylation, β-hydroxybutyrylation of histones, modulation of neurotransmitter systems and RNA functions. Administration of exogenous ketogenic supplements was proven to be an effective method to induce and maintain a healthy state of nutritional ketosis. Consequently, exogenous ketogenic supplements, such as ketone salts and ketone esters, may mitigate aging processes, delay the onset of age-associated diseases and extend lifespan through ketosis. The aim of this review is to summarize the main hallmarks of aging processes and certain signaling pathways in association with (putative) beneficial influences of exogenous ketogenic supplements-evoked ketosis on lifespan, aging processes, the most common age-related neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis), as well as impaired learning and memory functions.
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Affiliation(s)
- Zsolt Kovács
- Department of Biology, Savaria University Centre, ELTE Eötvös Loránd University, Károlyi Gáspár tér 4., 9700 Szombathely, Hungary; (Z.K.); (B.B.)
| | - Brigitta Brunner
- Department of Biology, Savaria University Centre, ELTE Eötvös Loránd University, Károlyi Gáspár tér 4., 9700 Szombathely, Hungary; (Z.K.); (B.B.)
- Faculty of Sciences, Institute of Biology, University of Pécs, Ifjúság Str. 6, 7624 Pécs, Hungary
| | - Csilla Ari
- Behavioral Neuroscience Research Laboratory, Department of Psychology, University of South Florida, 4202 E. Fowler Ave, PCD 3127, Tampa, FL 33620, USA
- Ketone Technologies LLC, 2780 E. Fowler Ave. #226, Tampa, FL 33612, USA
- Correspondence: ; Tel.: +1-(813)-2409925
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20
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Obesity and aging: Molecular mechanisms and therapeutic approaches. Ageing Res Rev 2021; 67:101268. [PMID: 33556548 DOI: 10.1016/j.arr.2021.101268] [Citation(s) in RCA: 94] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 01/19/2021] [Accepted: 02/02/2021] [Indexed: 02/08/2023]
Abstract
The epidemic of obesity is a major challenge for health policymakers due to its far-reaching effects on population health and potentially overwhelming financial burden on healthcare systems. Obesity is associated with an increased risk of developing acute and chronic diseases, including hypertension, stroke, myocardial infarction, cardiovascular disease, diabetes, and cancer. Interestingly, the metabolic dysregulation associated with obesity is similar to that observed in normal aging, and substantial evidence suggests the potential of obesity to accelerate aging. Therefore, understanding the mechanism of fat tissue dysfunction in obesity could provide insights into the processes that contribute to the metabolic dysfunction associated with the aging process. Here, we review the molecular and cellular mechanisms underlying both obesity and aging, and how obesity and aging can predispose individuals to chronic health complications. The potential of lifestyle and pharmacological interventions to counter obesity and obesity-related pathologies, as well as aging, is also addressed.
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21
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Abstract
Voltage-gated Kv1.1 potassium channel α-subunits are broadly expressed in the nervous system where they act as critical regulators of neuronal excitability. Mutations in the KCNA1 gene, which encodes Kv1.1, are associated with the neurological diseases episodic ataxia and epilepsy. Studies in mouse models have shown that Kv1.1 is important for neural control of the heart and that Kcna1 deletion leads to cardiac dysfunction that appears to be brain-driven. Traditionally, KCNA1 was not believed to be expressed in the heart. However, recent studies have revealed that Kv1.1 subunits are not only present in cardiomyocytes, but that they also make an important heart-intrinsic functional contribution to outward K+ currents and action potential repolarization. This review recounts the winding history of discovery of KCNA1 gene expression and neurocardiac function from fruit flies to mammals and from brain to heart and looks at some of the salient questions that remain to be answered regarding emerging cardiac roles of Kv1.1.
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Affiliation(s)
- Edward Glasscock
- a Department of Biological Sciences , Southern Methodist University , Dallas , TX , USA
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22
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Boison D, Rho JM. Epigenetics and epilepsy prevention: The therapeutic potential of adenosine and metabolic therapies. Neuropharmacology 2020; 167:107741. [PMID: 31419398 PMCID: PMC7220211 DOI: 10.1016/j.neuropharm.2019.107741] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/08/2019] [Accepted: 08/13/2019] [Indexed: 12/20/2022]
Abstract
Prevention of epilepsy and its progression remains the most urgent need for epilepsy research and therapy development. Novel conceptual advances are required to meaningfully address this fundamental challenge. Maladaptive epigenetic changes, which include methylation of DNA and acetylation of histones - among other mechanisms, are now well recognized to play a functional role in the development of epilepsy and its progression. The methylation hypothesis of epileptogenesis suggests that changes in DNA methylation are implicated in the progression of the disease. In this context, global DNA hypermethylation is particularly associated with chronic epilepsy. Likewise, acetylation changes of histones have been linked to epilepsy development. Clinical as well as experimental evidence demonstrate that epilepsy and its progression can be prevented by metabolic and biochemical manipulations that target previously unrecognized epigenetic functions contributing to epilepsy development and maintenance of the epileptic state. This review will discuss epigenetic mechanisms implicated in epilepsy development as well as metabolic and biochemical interactions thought to drive epileptogenesis. Therefore, metabolic and biochemical mechanisms are identified as novel targets for epilepsy prevention. We will specifically discuss adenosine biochemistry as a novel therapeutic strategy to reconstruct the DNA methylome as antiepileptogenic strategy as well as metabolic mediators, such as beta-hydroxybutyrate, which affect histone acetylation. Finally, metabolic dietary interventions (such as the ketogenic diet) which have the unique potential to prevent epileptogenesis through recently identified epigenetic mechanisms will be reviewed. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Detlev Boison
- Dept. of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA.
| | - Jong M Rho
- Depts. of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, CA, 92117, USA
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23
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D’Adamo MC, Liantonio A, Rolland JF, Pessia M, Imbrici P. Kv1.1 Channelopathies: Pathophysiological Mechanisms and Therapeutic Approaches. Int J Mol Sci 2020; 21:ijms21082935. [PMID: 32331416 PMCID: PMC7215777 DOI: 10.3390/ijms21082935] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 12/27/2022] Open
Abstract
Kv1.1 belongs to the Shaker subfamily of voltage-gated potassium channels and acts as a critical regulator of neuronal excitability in the central and peripheral nervous systems. KCNA1 is the only gene that has been associated with episodic ataxia type 1 (EA1), an autosomal dominant disorder characterized by ataxia and myokymia and for which different and variable phenotypes have now been reported. The iterative characterization of channel defects at the molecular, network, and organismal levels contributed to elucidating the functional consequences of KCNA1 mutations and to demonstrate that ataxic attacks and neuromyotonia result from cerebellum and motor nerve alterations. Dysfunctions of the Kv1.1 channel have been also associated with epilepsy and kcna1 knock-out mouse is considered a model of sudden unexpected death in epilepsy. The tissue-specific association of Kv1.1 with other Kv1 members, auxiliary and interacting subunits amplifies Kv1.1 physiological roles and expands the pathogenesis of Kv1.1-associated diseases. In line with the current knowledge, Kv1.1 has been proposed as a novel and promising target for the treatment of brain disorders characterized by hyperexcitability, in the attempt to overcome limited response and side effects of available therapies. This review recounts past and current studies clarifying the roles of Kv1.1 in and beyond the nervous system and its contribution to EA1 and seizure susceptibility as well as its wide pharmacological potential.
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Affiliation(s)
- Maria Cristina D’Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
| | - Antonella Liantonio
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
| | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain Po Box 17666, UAE
| | - Paola Imbrici
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
- Correspondence:
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24
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Clinical Spectrum of KCNA1 Mutations: New Insights into Episodic Ataxia and Epilepsy Comorbidity. Int J Mol Sci 2020; 21:ijms21082802. [PMID: 32316562 PMCID: PMC7215408 DOI: 10.3390/ijms21082802] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the KCNA1 gene, which encodes voltage-gated Kv1.1 potassium channel α-subunits, cause a variety of human diseases, complicating simple genotype–phenotype correlations in patients. KCNA1 mutations are primarily associated with a rare neurological movement disorder known as episodic ataxia type 1 (EA1). However, some patients have EA1 in combination with epilepsy, whereas others have epilepsy alone. KCNA1 mutations can also cause hypomagnesemia and paroxysmal dyskinesia in rare cases. Why KCNA1 variants are associated with such phenotypic heterogeneity in patients is not yet understood. In this review, literature databases (PubMed) and public genetic archives (dbSNP and ClinVar) were mined for known pathogenic or likely pathogenic mutations in KCNA1 to examine whether patterns exist between mutation type and disease manifestation. Analyses of the 47 deleterious KCNA1 mutations that were identified revealed that epilepsy or seizure-related variants tend to cluster in the S1/S2 transmembrane domains and in the pore region of Kv1.1, whereas EA1-associated variants occur along the whole length of the protein. In addition, insights from animal models of KCNA1 channelopathy were considered, as well as the possible influence of genetic modifiers on disease expressivity and severity. Elucidation of the complex relationship between KCNA1 variants and disease will enable better diagnostic risk assessment and more personalized therapeutic strategies for KCNA1 channelopathy.
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Iyer SH, Aggarwal A, Warren TJ, Hallgren J, Abel PW, Simeone TA, Simeone KA. Progressive cardiorespiratory dysfunction in Kv1.1 knockout mice may provide temporal biomarkers of pending sudden unexpected death in epilepsy (SUDEP): The contribution of orexin. Epilepsia 2020; 61:572-588. [PMID: 32030748 DOI: 10.1111/epi.16434] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 12/19/2019] [Accepted: 01/06/2020] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Immediately preceding sudden unexpected death in epilepsy (SUDEP), patients experienced a final generalized tonic-clonic seizure (GTCS), rapid ventilation, apnea, bradycardia, terminal apnea, and asystole. Whether a progressive pathophysiology develops and increases risk of SUDEP remains unknown. Here, we determined (a) heart rate, respiratory rate, and blood oxygen saturation (SaO2 ) in low-risk and high-risk knockout (KO) mice; and (b) whether blocking receptors for orexin, a cardiorespiratory neuromodulator, influences cardiorespiratory function mice or longevity in high-risk KO mice. METHODS Heart rate and SaO2 were determined noninvasively with ECGenie and pulse oximetry. Respiration was determined with noninvasive airway mechanics technology. The role of orexin was determined within subject following acute treatment with a dual orexin receptor antagonist (DORA, 100 mg/kg). The number of orexin neurons in the lateral hypothalamus was determined with immunohistochemistry. RESULTS Intermittent bradycardia was more prevalent in high-risk KO mice, an effect that may be the result of increased parasympathetic drive. High-risk KO mice had more orexin neurons in the lateral hypothalamus. Blocking of orexin receptors differentially influenced heart rate in KO, but not wild-type (WT) mice. When DORA administration increased heart rate, it also decreased heart rate variability, breathing frequency, and/or hypopnea-apnea. Blocking orexin receptors prevented the methacholine (MCh)-induced increase in breathing frequency in KO mice and reduced MCh-induced seizures, via a direct or indirect mechanism. DORA improved oxygen saturation in KO mice with intermittent hypoxia. Daily administration of DORA to high-risk KO mice increased longevity. SIGNIFICANCE High-risk KO mice have a unique cardiorespiratory phenotype that is characterized by progressive changes in five interdependent endpoints. Blocking of orexin receptors attenuates some of these endpoints and increases longevity, supporting the notion that windows of opportunity for intervention exist in this preclinical SUDEP model.
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Affiliation(s)
- Shruthi H Iyer
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Ankita Aggarwal
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Ted J Warren
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Jodi Hallgren
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Peter W Abel
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
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Trosclair K, Dhaibar HA, Gautier NM, Mishra V, Glasscock E. Neuron-specific Kv1.1 deficiency is sufficient to cause epilepsy, premature death, and cardiorespiratory dysregulation. Neurobiol Dis 2020; 137:104759. [PMID: 31978607 DOI: 10.1016/j.nbd.2020.104759] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/03/2020] [Accepted: 01/20/2020] [Indexed: 12/14/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related mortality, but the precise cellular substrates involved remain elusive. Epilepsy-associated ion channel genes with co-expression in brain and heart have been proposed as SUDEP candidate genes since they provide a singular unifying link between seizures and lethal cardiac arrhythmias. Here, we generated a conditional knockout (cKO) mouse with neuron-specific deletion of Kcna1, a SUDEP-associated gene with brain-heart co-expression, to test whether seizure-evoked cardiac arrhythmias and SUDEP require the absence of Kv1.1 in both brain and heart or whether ablation in neurons is sufficient. To obtain cKO mice, we developed a floxed Kcna1 mouse which we crossed to mice with the Synapsin1-Cre transgene, which selectively deletes Kcna1 in most neurons. Molecular analyses confirmed neuron-specific Kcna1 deletion in cKO mice and corresponding loss of Kv1.1 except in cerebellum where Synapsin1-Cre is not highly expressed. Survival studies and electroencephalography, electrocardiography, and plethysmography recordings showed that cKO mice exhibit premature death, epilepsy, and cardiorespiratory dysregulation but to a lesser degree than global knockouts. Heart rate variability (HRV) was increased in cKO mice with peaks during daytime suggesting disturbed diurnal HRV patterns as a SUDEP biomarker. Residual Kv1.1 expression in cKO cerebellum suggests it may play an unexpected role in regulating ictal cardiorespiratory dysfunction and SUDEP risk. This work demonstrates the principle that channelopathies with brain-heart expression patterns can increase death risk by brain-driven mechanisms alone without a functionally compromised heart, reinforcing seizure control as a primary clinical strategy for SUDEP prevention.
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Affiliation(s)
- Krystle Trosclair
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, LA 71103, United States of America.
| | - Hemangini A Dhaibar
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, LA 71103, United States of America.
| | - Nicole M Gautier
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, LA 71103, United States of America.
| | - Vikas Mishra
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, LA 71103, United States of America.
| | - Edward Glasscock
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, LA 71103, United States of America; Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, United States of America.
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Binder DK, Boison D, Eid T, Frankel WN, Mingorance A, Smith BN, Dacks PA, Whittemore V, Poduri A. Epilepsy Benchmarks Area II: Prevent Epilepsy and Its Progression. Epilepsy Curr 2020; 20:14S-22S. [PMID: 31937124 PMCID: PMC7031802 DOI: 10.1177/1535759719895274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Area II of the 2014 Epilepsy Research Benchmarks aims to establish goals for preventing the development and progression of epilepsy. In this review, we will highlight key advances in Area II since the last summary of research progress and opportunities was published in 2016. We also highlight areas of investigation that began to develop before 2016 and in which additional progress has been made more recently.
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Affiliation(s)
- Devin K Binder
- Division of Biomedical Sciences, School of Medicine, Center for Glial-Neuronal Interactions, University of California, Riverside, CA, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson and New Jersey Medical Schools, Rutgers University, Piscataway, NJ, USA
| | - Tore Eid
- Department of Laboratory Medicine, Neurosurgery and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Wayne N Frankel
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | | | - Bret N Smith
- Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY, USA
| | | | - Vicky Whittemore
- Division of Neuroscience, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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Li R, Buchanan GF. Scurrying to Understand Sudden Expected Death in Epilepsy: Insights From Animal Models. Epilepsy Curr 2019; 19:390-396. [PMID: 31526023 PMCID: PMC6891182 DOI: 10.1177/1535759719874787] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy, accounting for up to 17% of deaths in patients with epilepsy. The pathophysiology of SUDEP has remained unclear, largely because it is unpredictable and commonly unwitnessed. This poses a great challenge to studies in patients. Recently, there has been an increase in animal studies to try to better understand the pathophysiology of SUDEP. In this current review, we focus on developments through seizure-induced death models and the preventative strategies they may reveal.
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Affiliation(s)
- Rui Li
- Department of Neurology, Carver College of Medicine, University of Iowa, IA, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, IA, USA
| | - Gordon F. Buchanan
- Department of Neurology, Carver College of Medicine, University of Iowa, IA, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, IA, USA
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Ren Y, Chang J, Li C, Jia C, Li P, Wang Y, Chu XP. The Effects of Ketogenic Diet Treatment in Kcna1-Null Mouse, a Model of Sudden Unexpected Death in Epilepsy. Front Neurol 2019; 10:744. [PMID: 31354612 PMCID: PMC6635472 DOI: 10.3389/fneur.2019.00744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/26/2019] [Indexed: 12/16/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a leading cause of abrupt death in patient with epilepsy. It represents 5-30% of all rapid deaths in individuals with epilepsy. Ketogenic diet (KD) has been used in clinic for treatment of epilepsy for many decades. However, the cellular and molecular mechanisms underlying the SUDEP and the relationship between KD and SUDEP remain uncertain. Kcna1-null (Kcna1-/-) mouse, an animal model of SUDEP, is frequently used to study mechanisms underlying SUDEP. The current mini-review focus on risk factors for SUDEP and their relationship with KD treatment in Kcna1-/- mice. Emerging data suggest that factors including seizure frequency, longevity, rest, age, and gender both in Kcna1-/- mice and KD treated Kcna1-/-mice are involved in SUDEP. This provides valuable prediction for clinical application of KD for treatment of SUDEP.
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Affiliation(s)
- Yandong Ren
- School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Jinlong Chang
- School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Chengchong Li
- School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Cuicui Jia
- School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Ping Li
- School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Yuhua Wang
- School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Xiang-Ping Chu
- School of Mental Health, Qiqihar Medical University, Qiqihar, China.,Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
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30
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Teran FA, Kim Y, Crotts MS, Bravo E, Emaus KJ, Richerson GB. Time of Day and a Ketogenic Diet Influence Susceptibility to SUDEP in Scn1a R1407X/+ Mice. Front Neurol 2019; 10:278. [PMID: 30984098 PMCID: PMC6449461 DOI: 10.3389/fneur.2019.00278] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/04/2019] [Indexed: 01/02/2023] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a major cause of mortality in patients with drug-resistant epilepsy. Most SUDEP cases occur in bed at night and are preceded by a generalized tonic-clonic seizure (GTCS). Dravet syndrome (DS) is a severe childhood-onset epilepsy commonly caused by mutations in the SCN1A gene. Affected individuals suffer from refractory seizures and an increased risk of SUDEP. Here, we demonstrate that mice with the Scn1aR1407X/+ loss-of-function mutation (DS) experience more spontaneous seizures and SUDEP during the early night. We also evaluate effects of long-term ketogenic diet (KD) treatment on mortality and seizure frequency. DS mice showed high premature mortality (44% survival by P60) that was associated with increased spontaneous GTCSs 1–2 days prior to SUDEP. KD treated mice had a significant reduction in mortality (86% survival by P60) compared to mice fed a control diet. Interestingly, increased survival was not associated with a decrease in seizure frequency. Further studies are needed to determine how KD confers protection from SUDEP. Moreover, our findings implicate time of day as a factor influencing the occurrence of seizures and SUDEP. DS mice, though nocturnal, are more likely to have SUDEP at night, suggesting that the increased incidence of SUDEP at night in may not be solely due to sleep.
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Affiliation(s)
- Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA, United States.,Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States.,Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States
| | - YuJaung Kim
- Department of Neurology, University of Iowa, Iowa City, IA, United States.,Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States
| | - Megan S Crotts
- Department of Neurology, University of Iowa, Iowa City, IA, United States
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA, United States.,Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States
| | - Katlynn J Emaus
- Department of Neurology, University of Iowa, Iowa City, IA, United States
| | - George B Richerson
- Department of Neurology, University of Iowa, Iowa City, IA, United States.,Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States.,Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA, United States.,Neurology, Veterans Affairs Medical Center, Iowa City, IA, United States
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Chen F, He X, Luan G, Li T. Role of DNA Methylation and Adenosine in Ketogenic Diet for Pharmacoresistant Epilepsy: Focus on Epileptogenesis and Associated Comorbidities. Front Neurol 2019; 10:119. [PMID: 30863356 PMCID: PMC6399128 DOI: 10.3389/fneur.2019.00119] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/29/2019] [Indexed: 01/02/2023] Open
Abstract
Epilepsy is a neurological disorder characterized by a long term propensity to produce unprovoked seizures and by the associated comorbidities including neurological, cognitive, psychiatric, and impairment the quality of life. Despite the clinic availability of several novel antiepileptic drugs (AEDs) with different mechanisms of action, more than one-third of patients with epilepsy suffer with pharmacoresistant epilepsy. Until now, no AEDs have been proven to confer the efficacy in alteration of disease progression or inhibition of the development of epilepsy. The ketogenic diet, the high-fat, low-carbohydrate composition is an alternative metabolic therapy for epilepsy, especially for children with drug-resistant epilepsy. Recently clinical and experimental results demonstrate its efficacy in ameliorating both seizures and comorbidities associated with epilepsy, such as cognitive/psychiatric concerns for the patients with refractory epilepsy. Of importance, ketogenic diet demonstrates to be a promising disease-modifying or partial antiepileptogenesis therapy for epilepsy. The mechanisms of action of ketogenic diet in epilepsy have been revealed recently, such as epigenetic mechanism for increase the adenosine level in the brain and inhibition of DNA methylation. In the present review, we will focus on the mechanisms of ketogenic diet therapies underlying adenosine system in the prevention of epileptogenesis and disease modification. In addition, we will review the role of ketogenic diet therapy in comorbidities associated epilepsy and the underlying mechanisms of adenosine.
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Affiliation(s)
- Fan Chen
- Beijing Key Laboratory of Epilepsy Research, Department of Neurology, Beijing Institute for Brain Disorders, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Xinghui He
- Beijing Key Laboratory of Epilepsy Research, Department of Neurosurgery, Beijing Institute for Brain Disorders, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Guoming Luan
- Beijing Key Laboratory of Epilepsy Research, Department of Neurosurgery, Beijing Institute for Brain Disorders, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Tianfu Li
- Beijing Key Laboratory of Epilepsy Research, Department of Neurology, Beijing Institute for Brain Disorders, Sanbo Brain Hospital, Capital Medical University, Beijing, China
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Goswami JN, Sharma S. Current Perspectives On The Role Of The Ketogenic Diet In Epilepsy Management. Neuropsychiatr Dis Treat 2019; 15:3273-3285. [PMID: 31819454 PMCID: PMC6883945 DOI: 10.2147/ndt.s201862] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 10/18/2019] [Indexed: 12/31/2022] Open
Abstract
Drug-refractory epilepsy is a commonly prevalent pediatric neurological illness of global significance. Ketogenic diet (KD) is a time-tested therapeutic modality for refractory epilepsy, which has reemerged as a robust alternative to anti-epileptic pharmacotherapy. There is a growing body of evidence which supports the anti-seizure efficacy, safety profile and feasibility of KD use in childhood epilepsy. In addition, this modality has been recognized to reduce anti-epileptic exposure, improve cognition and behavioral profile of patients as well as improve the quality-of-life of care-givers. Current indications of KD include refractory epilepsy syndromes, selected metabolic disorders (such as pyruvate dehydrogenase deficiency) and a host of varied neurological entities. KD research has broadened the knowledge-base about its mechanisms of action. Four types of KD are in vogue currently with varying nutritional constitution, palatability, administration protocols and comparable efficacy. KD initiation and maintenance are the result of concerted effort of a team of pediatric neurologist/epileptologist, nutritionist and patient's primary care-giver. Consensus is being formulated about various practical aspects of KD such as patient-selection, parental counseling, baseline work-up, dietary prescription, nutritional supplementation, concurrent anti-epileptic drug administration, follow-up and treatment-duration. Novel applications of KD include its use in neonatal epilepsy and super-refractory status epilepticus and tailor-made formulations such as cooking oil-based KD in predominantly rice-fed populations. Increasing body of clinical experience, improved nutritional designs and translational research are promoting KD as a major therapeutic modality. Currently, KD forms a core essence in the armamentarium against refractory epilepsy. In this review, we summarize the recent advances and current perspectives in the use of KD in refractory epilepsy.
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Affiliation(s)
| | - Suvasini Sharma
- Neurology Division, Department of Pediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children's Hospital, New Delhi 110001, India
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Ketogenic diet regulates the antioxidant catalase via the transcription factor PPARγ2. Epilepsy Res 2018; 147:71-74. [PMID: 30261354 DOI: 10.1016/j.eplepsyres.2018.09.009] [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: 07/05/2018] [Revised: 08/29/2018] [Accepted: 09/18/2018] [Indexed: 12/20/2022]
Abstract
We have previously found that the transcription factor PPARγ2 contributes to the mechanism of action of the ketogenic diet (KD), an established treatment for pediatric refractory epilepsy. Among the wide-array of genes regulated by PPARγ, previous studies have suggested that antioxidants such as catalase may have prominent roles in KD neuroprotective and antiseizure effects. Here, we tested the hypothesis that the KD increases catalase through activation of PPARγ2, and that this action is part of the mechanism of antiseizure efficacy of the KD. We determined catalase mRNA and protein expression in hippocampal tissue from epileptic Kcna1-/- mice, Pparγ2+/+ mice and Pparγ2-/- mice. We found that a KD increases hippocampal catalase expression in Kcna1-/- and Pparγ2+/+ mice, but not Pparγ2-/- mice. Next, we determined whether catalase contributes to KD seizure protection. We found that the KD reduces pentylenetetrazole (PTZ)-induced seizures; however, pretreatment with a catalase inhibitor occluded KD effects on PTZ seizures. These results suggest that the KD regulates catalase expression through PPARγ2 activation, and that catalase may contribute to the KD antiseizure efficacy.
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Sada N, Inoue T. Electrical Control in Neurons by the Ketogenic Diet. Front Cell Neurosci 2018; 12:208. [PMID: 30061816 PMCID: PMC6054928 DOI: 10.3389/fncel.2018.00208] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/26/2018] [Indexed: 01/01/2023] Open
Abstract
The ketogenic diet is used as a diet treatment for drug-resistant epilepsy, but there are no antiepileptic drugs based on the ketogenic diet. The ketogenic diet changes energy metabolites (ketone bodies, glucose and lactate) in the brain, which consequently changes electrical activities in neurons and ultimately suppresses seizures in epileptic patients. In order to elucidate the antiseizure effects of the ketogenic diet, it is important to clarify the mechanism by which these metabolic changes are converted to electrical changes in neurons. In this review, we summarize electrophysiological studies focusing on electrical control in neurons by the ketogenic diet. Recent studies have identified electrical regulators driven by the ketogenic diet: ion channels (ATP-sensitive K+ channels and voltage-dependent Ca2+ channels), synaptic receptors (AMPA-type glutamate receptors and adenosine A1 receptors), neurotransmitter transporters (vesicular glutamate transporters), and others (BCL-2-associated agonist of cell death and lactate dehydrogenase). Thus, the ketogenic diet presumably elicits neuronal inhibition via the combined actions of these molecules. From the viewpoint of drug development, these molecules are valuable as targets for the development of new antiepileptic drugs. Drug therapy to mimic the ketogenic diet may be feasible in the future, through the combination of multiple antiepileptic drugs targeting these molecules.
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Affiliation(s)
- Nagisa Sada
- Department of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
- Department of Hygiene, Kawasaki Medical School, Kurashiki, Japan
| | - Tsuyoshi Inoue
- Department of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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Olson CA, Vuong HE, Yano JM, Liang QY, Nusbaum DJ, Hsiao EY. The Gut Microbiota Mediates the Anti-Seizure Effects of the Ketogenic Diet. Cell 2018; 173:1728-1741.e13. [PMID: 29804833 PMCID: PMC6003870 DOI: 10.1016/j.cell.2018.04.027] [Citation(s) in RCA: 555] [Impact Index Per Article: 92.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/02/2018] [Accepted: 04/19/2018] [Indexed: 01/16/2023]
Abstract
The ketogenic diet (KD) is used to treat refractory epilepsy, but the mechanisms underlying its neuroprotective effects remain unclear. Here, we show that the gut microbiota is altered by the KD and required for protection against acute electrically induced seizures and spontaneous tonic-clonic seizures in two mouse models. Mice treated with antibiotics or reared germ free are resistant to KD-mediated seizure protection. Enrichment of, and gnotobiotic co-colonization with, KD-associated Akkermansia and Parabacteroides restores seizure protection. Moreover, transplantation of the KD gut microbiota and treatment with Akkermansia and Parabacteroides each confer seizure protection to mice fed a control diet. Alterations in colonic lumenal, serum, and hippocampal metabolomic profiles correlate with seizure protection, including reductions in systemic gamma-glutamylated amino acids and elevated hippocampal GABA/glutamate levels. Bacterial cross-feeding decreases gamma-glutamyltranspeptidase activity, and inhibiting gamma-glutamylation promotes seizure protection in vivo. Overall, this study reveals that the gut microbiota modulates host metabolism and seizure susceptibility in mice.
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Affiliation(s)
- Christine A Olson
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Helen E Vuong
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jessica M Yano
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Qingxing Y Liang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - David J Nusbaum
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elaine Y Hsiao
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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Abstract
PURPOSE OF REVIEW High-fat, low-carbohydrate ketogenic diets have been used for almost a century for the treatment of epilepsy. Used traditionally for the treatment of refractory pediatric epilepsies, in recent years the use of ketogenic diets has experienced a revival to include the treatment of adulthood epilepsies as well as conditions ranging from autism to chronic pain and cancer. Despite the ability of ketogenic diet therapy to suppress seizures refractory to antiepileptic drugs and reports of lasting seizure freedom, the underlying mechanisms are poorly understood. This review explores new insights into mechanisms mobilized by ketogenic diet therapies. RECENT FINDINGS Ketogenic diets act through a combination of mechanisms, which are linked to the effects of ketones and glucose restriction, and to interactions with receptors, channels, and metabolic enzymes. Decanoic acid, a component of medium-chain triclycerides, contributes to seizure control through direct α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor inhibition, whereas drugs targeting lactate dehydrogenase reduce seizures through inhibition of a metabolic pathway. Ketogenic diet therapy also affects DNA methylation, a novel epigenetic mechanism of the diet. SUMMARY Ketogenic diet therapy combines several beneficial mechanisms that provide broad benefits for the treatment of epilepsy with the potential to not only suppress seizures but also to modify the course of the epilepsy.
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Simeone TA, Simeone KA, Stafstrom CE, Rho JM. Do ketone bodies mediate the anti-seizure effects of the ketogenic diet? Neuropharmacology 2018; 133:233-241. [PMID: 29325899 PMCID: PMC5858992 DOI: 10.1016/j.neuropharm.2018.01.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 11/27/2017] [Accepted: 01/07/2018] [Indexed: 01/01/2023]
Abstract
Although the mechanisms underlying the anti-seizure effects of the high-fat ketogenic diet (KD) remain unclear, a long-standing question has been whether ketone bodies (i.e., β-hydroxybutyrate, acetoacetate and acetone), either alone or in combination, contribute mechanistically. The traditional belief has been that while ketone bodies reflect enhanced fatty acid oxidation and a general shift toward intermediary metabolism, they are not likely to be the key mediators of the KD's clinical effects, as blood levels of β-hydroxybutyrate do not correlate consistently with improved seizure control. Against this unresolved backdrop, new data support ketone bodies as having anti-seizure actions. Specifically, β-hydroxybutyrate has been shown to interact with multiple novel molecular targets such as histone deacetylases, hydroxycarboxylic acid receptors on immune cells, and the NLRP3 inflammasome. Clearly, as a diet-based therapy is expected to render a broad array of biochemical, molecular, and cellular changes, no single mechanism can explain how the KD works. Specific metabolic substrates or enzymes are only a few of many important factors influenced by the KD that can collectively influence brain hyperexcitability and hypersynchrony. This review summarizes recent novel experimental findings supporting the anti-seizure and neuroprotective properties of ketone bodies.
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Affiliation(s)
- Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Carl E Stafstrom
- Department of Neurology, and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jong M Rho
- Department of Pediatrics, Department of Clinical Neurosciences, and Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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Warren TJ, Simeone TA, Smith DD, Grove R, Adamec J, Samson KK, Roundtree HM, Madhavan D, Simeone KA. Adenosine has two faces: Regionally dichotomous adenosine tone in a model of epilepsy with comorbid sleep disorders. Neurobiol Dis 2018; 114:45-52. [PMID: 29409952 DOI: 10.1016/j.nbd.2018.01.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/29/2017] [Accepted: 01/24/2018] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE Adenosine participates in maintaining the excitatory/inhibitory balance in neuronal circuits. Studies indicate that adenosine levels in the cortex and hippocampus increase and exert sleep pressure in sleep-deprived and control animals, whereas in epilepsy reduced adenosine tone promotes hyperexcitability. To date, the role of adenosine in pathological conditions that result in both seizures and sleep disorders is unknown. Here, we determined adenosine tone in sleep and seizure regulating brain regions of Kv1.1 knockout (KO) mice, a model of temporal epilepsy with comorbid sleep disorders. METHODS 1) Reverse phase-high performance liquid chromatography (RP-HPLC) was performed on brain tissue to determine levels of adenosine and adenine nucleotides. 2) Multi-electrode array extracellular electrophysiology was used to determine adenosine tone in the hippocampal CA1 region and the lateral hypothalamus (LH). RESULTS RP-HPLC indicated a non-significant decrease in adenosine (~50%, p = 0.23) in whole brain homogenates of KO mice. Regional examination of relative levels of adenine nucleotides indicated decreased ATP and increased AMP in the cortex and hippocampus and increased adenosine in cortical tissue. Using electrophysiological and pharmacological techniques, estimated adenosine levels were ~35% lower in the KO hippocampal CA1 region, and 1-2 fold higher in the KO LH. Moreover, the increased adenosine in KO LH contributed to lower spontaneous firing rates of putative wake-promoting orexin/hypocretin neurons. INTERPRETATION This is the first study to demonstrate a direct correlation of regionally distinct dichotomous adenosine levels in a single model with both epilepsy and comorbid sleep disorders. The weaker inhibitory tone in the dorsal hippocampus is consistent with lower seizure threshold, whereas increased adenosine in the LH is consistent with chronic partial sleep deprivation. This work furthers our understanding of how adenosine may contribute to pathological conditions that underlie sleep disorders within the epileptic brain.
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Affiliation(s)
- Ted J Warren
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE 68178, United States
| | - Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE 68178, United States
| | - D David Smith
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, United States
| | - Ryan Grove
- Department of Biochemistry and Redox Biology Center, University of Nebraska - Lincoln, Lincoln, NE 68588, United States
| | - Jiri Adamec
- Department of Biochemistry and Redox Biology Center, University of Nebraska - Lincoln, Lincoln, NE 68588, United States
| | - Kaeli K Samson
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE 68178, United States; Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Harrison M Roundtree
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE 68178, United States
| | - Deepak Madhavan
- Department of Neurological Sciences, Nebraska Comprehensive Epilepsy Program, University of Nebraska Medical Center, Omaha, NE 68198, United States
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE 68178, United States.
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Simeone KA, Hallgren J, Bockman CS, Aggarwal A, Kansal V, Netzel L, Iyer SH, Matthews SA, Deodhar M, Oldenburg PJ, Abel PW, Simeone TA. Respiratory dysfunction progresses with age in Kcna1-null mice, a model of sudden unexpected death in epilepsy. Epilepsia 2018; 59:345-357. [PMID: 29327348 DOI: 10.1111/epi.13971] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Increased breathing rate, apnea, and respiratory failure are associated with sudden unexpected death in epilepsy (SUDEP). We recently demonstrated the progressive nature of epilepsy and mortality in Kcna1-/- mice, a model of temporal lobe epilepsy and SUDEP. Here we tested the hypothesis that respiratory dysfunction progresses with age in Kcna1-/- mice, thereby increasing risk of respiratory failure and sudden death (SD). METHODS Respiratory parameters were determined in conscious mice at baseline and following increasing doses of methacholine (MCh) using noninvasive airway mechanics (NAM) systems. Kcna1+/+ , Kcna1+/- , and Kcna1-/- littermates were assessed during 3 age ranges when up to ~30%, ~55%, and ~90% of Kcna1-/- mice have succumbed to SUDEP: postnatal day (P) 32-36, P40-46, and P48-56, respectively. Saturated arterial O2 (SaO2 ) was determined with pulse oximetry. Lung and brain tissues were isolated and Kcna1 gene and protein expression were evaluated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and Western blot techniques. Airway smooth muscle responsiveness was assessed in isolated trachea exposed to MCh. RESULTS Kcna1-/- mice experienced an increase in basal respiratory drive, chronic oxygen desaturation, frequent apnea-hypopnea (A-H), an atypical breathing sequence of A-H-tachypnea-A-H, increased tidal volume, and hyperventilation induced by MCh. The MCh-provoked hyperventilation was dramatically attenuated with age. Of interest, only Kcna1-/- mice developed seizures following exposure to MCh. Seizures were provoked by lower concentrations of MCh as Kcna1-/- mice approached SD. MCh-induced seizures experienced by a subset of younger Kcna1-/- mice triggered death. Respiratory parameters of these younger Kcna1-/- mice resembled older near-SD Kcna1-/- mice. Kcna1 gene and protein were not expressed in Kcna1+/+ and Kcna1+/- lungs, and MCh-mediated airway smooth muscle contractions exhibited similar half-maximal effective concentration( EC50 ) in isolated Kcna1+/+ and Kcna1-/- trachea. SIGNIFICANCE The Kcna1-/- model of SUDEP exhibits progressive respiratory dysfunction, which suggests a potential increased susceptibility for respiratory failure during severe seizures that may result in sudden death.
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Affiliation(s)
- Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Jodi Hallgren
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Charles S Bockman
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Ankita Aggarwal
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Vikash Kansal
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Lauren Netzel
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Shruthi H Iyer
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Stephanie A Matthews
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Malavika Deodhar
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Peter J Oldenburg
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Peter W Abel
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
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Oyrer J, Maljevic S, Scheffer IE, Berkovic SF, Petrou S, Reid CA. Ion Channels in Genetic Epilepsy: From Genes and Mechanisms to Disease-Targeted Therapies. Pharmacol Rev 2018; 70:142-173. [PMID: 29263209 DOI: 10.1124/pr.117.014456] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
Epilepsy is a common and serious neurologic disease with a strong genetic component. Genetic studies have identified an increasing collection of disease-causing genes. The impact of these genetic discoveries is wide reaching-from precise diagnosis and classification of syndromes to the discovery and validation of new drug targets and the development of disease-targeted therapeutic strategies. About 25% of genes identified in epilepsy encode ion channels. Much of our understanding of disease mechanisms comes from work focused on this class of protein. In this study, we review the genetic, molecular, and physiologic evidence supporting the pathogenic role of a number of different voltage- and ligand-activated ion channels in genetic epilepsy. We also review proposed disease mechanisms for each ion channel and highlight targeted therapeutic strategies.
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Affiliation(s)
- Julia Oyrer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Ingrid E Scheffer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Samuel F Berkovic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Christopher A Reid
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
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Iyer SH, Matthews SA, Simeone TA, Maganti R, Simeone KA. Accumulation of rest deficiency precedes sudden death of epileptic Kv1.1 knockout mice, a model of sudden unexpected death in epilepsy. Epilepsia 2017; 59:92-105. [PMID: 29193044 DOI: 10.1111/epi.13953] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2017] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Chronic sleep deficiency is associated with early mortality. In the epileptic population, there is a higher prevalence of sleep disorders, and individuals with severe refractory epilepsy are at greater risk of premature mortality than the general population. Sudden unexpected death in epilepsy affects 1:1000 cases of epilepsy each year. Ketogenic diet (KD) treatment is one of the few effective options for refractory seizures. Despite KD reducing seizures and increasing longevity in Kv1.1 knockout (KO) mice, they still succumb to sudden death. This study aims to determine whether (1) the rest profiles of KO and KD-treated KO (KOKD) mice resemble each other as a function of either age or proximity to death and (2) the timing of death correlates with acute or chronic changes in rest. METHODS Noninvasive actimetry was used to monitor rest throughout the lives of KO and wild-type (WT) littermates administered standard diet or KD. RESULTS As KO mice age, rest is reduced (P < .0001). Rest is significantly improved in KDKO mice (P < .0001), resembling WT values at several ages. When age is removed as a variable and data are realigned to the day of death, the rest profiles of KO and KOKD groups worsen to similar degrees as a function of proximity to death. The amount of rest acutely is not sensitive to the timing of death, whereas chronic rest deficiency profiles (10-15 days prior to death) of both groups were indistinguishable. Chronic accumulation of rest deficiency over the final 15 days was associated with 75% of deaths. SIGNIFICANCE Our data suggest that the accumulated rest deficiency is associated with sudden death in Kv1.1 KO mice. These data (1) support the proposed clinical hypothesis that chronic sleep deficiency may be associated with early mortality in epileptic patients and (2) warrant future preclinical and clinical studies on sleep monitoring in epileptic patients.
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Affiliation(s)
- Shruthi H Iyer
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Stephanie A Matthews
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Rama Maganti
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
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Foley J, Burnham V, Tedoldi M, Danial NN, Yellen G. BAD knockout provides metabolic seizure resistance in a genetic model of epilepsy with sudden unexplained death in epilepsy. Epilepsia 2017; 59:e1-e4. [PMID: 29171006 DOI: 10.1111/epi.13960] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2017] [Indexed: 12/30/2022]
Abstract
Metabolic alteration, either through the ketogenic diet (KD) or by genetic alteration of the BAD protein, can produce seizure protection in acute chemoconvulsant models of epilepsy. To assess the seizure-protective role of knocking out (KO) the Bad gene in a chronic epilepsy model, we used the Kcna1-/- model of epilepsy, which displays progressively increased seizure severity and recapitulates the early death seen in sudden unexplained death in epilepsy (SUDEP). Beginning on postnatal day 24 (P24), we continuously video monitored Kcna1-/- and Kcna1-/- Bad-/- double knockout mice to assess survival and seizure severity. We found that Kcna1-/- Bad-/- mice outlived Kcna1-/- mice by approximately 2 weeks. Kcna1-/- Bad-/- mice also spent significantly less time in seizure than Kcna1-/- mice on P24 and the day of death, showing that BadKO provides seizure resistance in a genetic model of chronic epilepsy.
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Affiliation(s)
- Jeannine Foley
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Veronica Burnham
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Meghan Tedoldi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Nika N Danial
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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Chun KC, Ma SC, Oh H, Rho JM, Kim DY. Ketogenic diet-induced extension of longevity in epileptic Kcna1-null mice is influenced by gender and age at treatment onset. Epilepsy Res 2017; 140:53-55. [PMID: 29245026 DOI: 10.1016/j.eplepsyres.2017.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 11/07/2017] [Accepted: 11/16/2017] [Indexed: 02/03/2023]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a leading cause of premature mortality in patients with epilepsy, and has been linked to multiple risk factors, including gender and early age at seizure onset. Despite the lack of a targeted therapy for SUDEP, it has recently been shown that a high-fat, low carbohydrate ketogenic diet (KD) enhances longevity in the epileptic Kcna1-null (KO) mouse, a validated model of SUDEP. Here, we asked whether the KD-driven prolongation of lifespan in KO mice is dependent on sex and/or age at treatment onset. We found that as KO mice aged, their daily seizure frequency steadily increased, but had early demise by postnatal day (PD) 46.9±0.8. In KO mice started on the KD at PD30, longevity was extended to a mean of PD69.8±1.7, accompanied with improved seizure control. Interestingly, while seizure control on the KD was similar between male and female mice, KD-fed female KO mice survived longer than their male counterparts. Further, epileptic mice initiated on the KD at PD25 had longer lifespans compared to those placed on the KD starting at PD35. Collectively, these data further support the notion that the KD can retard disease progression and sudden death in KO mice, but that this beneficial action is influenced by gender and age at the start of treatment.
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Affiliation(s)
- Kyoung-Chul Chun
- Departments of Neurobiology and Neurology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, AZ, USA; Departments of Obstetrics and Gynecology, College of Medicine, Inje University, Ilsan-Paik Hospital, Gyeonggi, Korea
| | - Shun-Chieh Ma
- Departments of Neurobiology and Neurology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, AZ, USA
| | - Hyoungil Oh
- Departments of Neurobiology and Neurology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, AZ, USA
| | - Jong M Rho
- Departments of Pediatrics, Clinical Neurosciences, Physiology & Pharmacology, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Do Young Kim
- Departments of Neurobiology and Neurology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, AZ, USA.
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Boison D, Steinhäuser C. Epilepsy and astrocyte energy metabolism. Glia 2017; 66:1235-1243. [PMID: 29044647 DOI: 10.1002/glia.23247] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/29/2017] [Accepted: 10/02/2017] [Indexed: 12/17/2022]
Abstract
Epilepsy is a complex neurological syndrome characterized by neuronal hyperexcitability and sudden, synchronized electrical discharges that can manifest as seizures. It is now increasingly recognized that impaired astrocyte function and energy homeostasis play key roles in the pathogenesis of epilepsy. Excessive neuronal discharges can only happen, if adequate energy sources are made available to neurons. Conversely, energy depletion during seizures is an endogenous mechanism of seizure termination. Astrocytes control neuronal energy homeostasis through neurometabolic coupling. In this review, we will discuss how astrocyte dysfunction in epilepsy leads to distortion of key metabolic and biochemical mechanisms. Dysfunctional glutamate metabolism in astrocytes can directly contribute to neuronal hyperexcitability. Closure of astrocyte intercellular gap junction coupling as observed early during epileptogenesis limits activity-dependent trafficking of energy metabolites, but also impairs clearance of the extracellular space from accumulation of K+ and glutamate. Dysfunctional astrocytes also increase the metabolism of adenosine, a metabolic product of ATP degradation that broadly inhibits energy-consuming processes as an evolutionary adaptation to conserve energy. Due to the critical role of astroglial energy homeostasis in the control of neuronal excitability, metabolic therapeutic approaches that prevent the utilization of glucose might represent a potent antiepileptic strategy. In particular, high fat low carbohydrate "ketogenic diets" as well as inhibitors of glycolysis and lactate metabolism are of growing interest for the therapy of epilepsy.
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Affiliation(s)
- Detlev Boison
- R.S. Dow Neurobiology Laboratories, Legacy Research Institute, Portland, Oregon
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Mishra V, Karumuri BK, Gautier NM, Liu R, Hutson TN, Vanhoof-Villalba SL, Vlachos I, Iasemidis L, Glasscock E. Scn2a deletion improves survival and brain-heart dynamics in the Kcna1-null mouse model of sudden unexpected death in epilepsy (SUDEP). Hum Mol Genet 2017; 26:2091-2103. [PMID: 28334922 DOI: 10.1093/hmg/ddx104] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/13/2017] [Indexed: 12/20/2022] Open
Abstract
People with epilepsy have greatly increased probability of premature mortality due to sudden unexpected death in epilepsy (SUDEP). Identifying which patients are most at risk of SUDEP is hindered by a complex genetic etiology, incomplete understanding of the underlying pathophysiology and lack of prognostic biomarkers. Here we evaluated heterozygous Scn2a gene deletion (Scn2a+/-) as a protective genetic modifier in the Kcna1 knockout mouse (Kcna1-/-) model of SUDEP, while searching for biomarkers of SUDEP risk embedded in electroencephalography (EEG) and electrocardiography (ECG) recordings. The human epilepsy gene Kcna1 encodes voltage-gated Kv1.1 potassium channels that act to dampen neuronal excitability whereas Scn2a encodes voltage-gated Nav1.2 sodium channels important for action potential initiation and conduction. SUDEP-prone Kcna1-/- mice with partial genetic ablation of Nav1.2 channels (i.e. Scn2a+/-; Kcna1-/-) exhibited a two-fold increase in survival. Classical analysis of EEG and ECG recordings separately showed significantly decreased seizure durations in Scn2a+/-; Kcna1-/- mice compared with Kcna1-/- mice, without substantial modification of cardiac abnormalities. Novel analysis of the EEG and ECG together revealed a significant reduction in EEG-ECG association in Kcna1-/- mice compared with wild types, which was partially restored in Scn2a+/-; Kcna1-/- mice. The degree of EEG-ECG association was also proportional to the survival rate of mice across genotypes. These results show that Scn2a gene deletion acts as protective genetic modifier of SUDEP and suggest measures of brain-heart association as potential indices of SUDEP susceptibility.
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Affiliation(s)
- Vikas Mishra
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Bharat K Karumuri
- Biomedical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
| | - Nicole M Gautier
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Rui Liu
- Department of Mathematics and Statistics, Louisiana Tech University, Ruston, LA 71272, USA
| | - Timothy N Hutson
- Biomedical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
| | - Stephanie L Vanhoof-Villalba
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Ioannis Vlachos
- Department of Mathematics and Statistics, Louisiana Tech University, Ruston, LA 71272, USA
| | - Leonidas Iasemidis
- Biomedical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
| | - Edward Glasscock
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
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Kephart WC, Mumford PW, Mao X, Romero MA, Hyatt HW, Zhang Y, Mobley CB, Quindry JC, Young KC, Beck DT, Martin JS, McCullough DJ, D'Agostino DP, Lowery RP, Wilson JM, Kavazis AN, Roberts MD. The 1-Week and 8-Month Effects of a Ketogenic Diet or Ketone Salt Supplementation on Multi-Organ Markers of Oxidative Stress and Mitochondrial Function in Rats. Nutrients 2017; 9:nu9091019. [PMID: 28914762 PMCID: PMC5622779 DOI: 10.3390/nu9091019] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 11/16/2022] Open
Abstract
We determined the short- and long-term effects of a ketogenic diet (KD) or ketone salt (KS) supplementation on multi-organ oxidative stress and mitochondrial markers. For short-term feedings, 4 month-old male rats were provided isocaloric amounts of KD (n = 10), standard chow (SC) (n = 10) or SC + KS (~1.2 g/day, n = 10). For long-term feedings, 4 month-old male rats were provided KD (n = 8), SC (n = 7) or SC + KS (n = 7) for 8 months and rotarod tested every 2 months. Blood, brain (whole cortex), liver and gastrocnemius muscle were harvested from all rats for biochemical analyses. Additionally, mitochondria from the brain, muscle and liver tissue of long-term-fed rats were analyzed for mitochondrial quantity (maximal citrate synthase activity), quality (state 3 and 4 respiration) and reactive oxygen species (ROS) assays. Liver antioxidant capacity trended higher in short-term KD- and SC + KS-fed versus SC-fed rats, and short-term KD-fed rats exhibited significantly greater serum ketones compared to SC + KS-fed rats indicating that the diet (not KS supplementation) induced ketonemia. In long term-fed rats: (a) serum ketones were significantly greater in KD- versus SC- and SC + KS-fed rats; (b) liver antioxidant capacity and glutathione peroxidase protein was significantly greater in KD- versus SC-fed rats, respectively, while liver protein carbonyls were lowest in KD-fed rats; and (c) gastrocnemius mitochondrial ROS production was significantly greater in KD-fed rats versus other groups, and this paralleled lower mitochondrial glutathione levels. Additionally, the gastrocnemius pyruvate-malate mitochondrial respiratory control ratio was significantly impaired in long-term KD-fed rats, and gastrocnemius mitochondrial quantity was lowest in these animals. Rotarod performance was greatest in KD-fed rats versus all other groups at 2, 4 and 8 months, although there was a significant age-related decline in performance existed in KD-fed rats which was not evident in the other two groups. In conclusion, short- and long-term KD improves select markers of liver oxidative stress compared to SC feeding, although long-term KD feeding may negatively affect skeletal muscle mitochondrial physiology.
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Affiliation(s)
- Wesley C Kephart
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - Petey W Mumford
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - Xuansong Mao
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - Matthew A Romero
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - Hayden W Hyatt
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
| | - Yufeng Zhang
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA.
| | | | - John C Quindry
- Department of Human Health Performance, University of Montana, Missoula, MT 59812, USA.
| | - Kaelin C Young
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
- Department of Cell Biology and Physiology, Edward via College of Osteopathic Medicine-Auburn Campus, Auburn, AL 36849, USA.
| | - Darren T Beck
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
- Department of Cell Biology and Physiology, Edward via College of Osteopathic Medicine-Auburn Campus, Auburn, AL 36849, USA.
| | - Jeffrey S Martin
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
- Department of Cell Biology and Physiology, Edward via College of Osteopathic Medicine-Auburn Campus, Auburn, AL 36849, USA.
| | - Danielle J McCullough
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
- Department of Cell Biology and Physiology, Edward via College of Osteopathic Medicine-Auburn Campus, Auburn, AL 36849, USA.
| | - Dominic P D'Agostino
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL 33620, USA.
| | - Ryan P Lowery
- Applied Sports Performance Institute, Tampa, FL 33607, USA.
| | - Jacob M Wilson
- Applied Sports Performance Institute, Tampa, FL 33607, USA.
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
- Department of Cell Biology and Physiology, Edward via College of Osteopathic Medicine-Auburn Campus, Auburn, AL 36849, USA.
| | - Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
- Department of Cell Biology and Physiology, Edward via College of Osteopathic Medicine-Auburn Campus, Auburn, AL 36849, USA.
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Qu J, Lu SH, Lu ZL, Xu P, Xiang DX, Qu Q. Pharmacogenetic and case-control study on potassium channel related gene variants and genetic generalized epilepsy. Medicine (Baltimore) 2017; 96:e7321. [PMID: 28658141 PMCID: PMC5500063 DOI: 10.1097/md.0000000000007321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Potassium channels are the targets of antiepileptic drugs (AEDs), which play important roles in the etiology of epilepsy. KCNA1 and KCNA2 encode mammalian Kv1.1 and Kv1.2 channels, which are essential roles in the initiation and shaping of action potentials. KCNV2 encodes Kv8.2, which is a regional overlap with Kv2 subunits as functional heterotetramers. In our study, we aim to investigate whether variants of KCNA1, KCNA2, and KCNV2 genes influence susceptibility to genetic generalized epilepsies (GGEs) and the efficacy of AEDs. Seven hundred sixty-seven subjects (284 healthy controls, 279 drug-responsive, and 204 drug-resistant GGE patients) were enrolled in our study. Eight variants of KCNA1, KCNA2, and KCNV2 were assessed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry method. Results showed that there were no statistically significant correlations between the 8 variants of KCNA1, KCNA2, and KCNV2 and the risk/drug resistance of GGEs. In conclusion, our study suggests that KCNA1, KCNA2, and KCNV2 variants may not be involved in the risk/drug resistance of GGEs. Further multicenter, multiethnic, and large sample size pharmacogenetic and case-control studies are warranted to confirm our negative results.
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Affiliation(s)
- Jian Qu
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Institute of Clinical Pharmacy
| | - Shao-Hua Lu
- Department of Neurosurgery, the Third Xiangya Hospital
| | - Zhi-Li Lu
- Department of Pathology, the Affiliated Cancer Hospital of Xiangya School of Medicine
| | - Ping Xu
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Institute of Clinical Pharmacy
| | - Da-Xiong Xiang
- Department of Pharmacy, the Second Xiangya Hospital, Central South University, Institute of Clinical Pharmacy
| | - Qiang Qu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, P. R. China
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Simeone TA, Matthews SA, Simeone KA. Synergistic protection against acute flurothyl-induced seizures by adjuvant treatment of the ketogenic diet with the type 2 diabetes drug pioglitazone. Epilepsia 2017; 58:1440-1450. [PMID: 28555877 DOI: 10.1111/epi.13809] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2017] [Indexed: 12/26/2022]
Abstract
OBJECTIVE We have previously found that the transcription factor peroxisome proliferator-activated receptor γ (PPARγ) contributes to the mechanism of action of the ketogenic diet (KD), an established treatment for pediatric refractory epilepsy. We have found that the KD increases brain PPARγ and that inhibition or genetic loss of PPARγ prevents the antiseizure effects of the KD on (1) acutely induced seizures in nonepileptic mice and (2) spontaneous recurrent seizures in epileptic mice. Here, we tested the hypothesis that adjuvant treatment of KD-treated mice with a PPARγ agonist, pioglitazone, would result in an additive effect. METHODS Acute seizures were induced in three groups of C57Bl/6 mice by inhalation exposure to flurothyl gas. In Group 1, mice were weaned onto either a standard diet or KD comprised of a fat:carbohydrate/protein ratio of either 6:1, 3:1, or 1:1 for 2 weeks. In Group 2, vehicle or pioglitazone (0.1, 1, 10, 80 mg/kg) was administered 4 h prior to flurothyl exposure. In Group 3, vehicle or increasing doses of pioglitazone were administered to KD-treated mice 4 h prior to flurothyl exposure. Latency times to clonic seizures and generalized tonic-clonic (GTC) seizures were recorded, and isobolographic analysis was used to determine combinatorial interactions. RESULTS Neither KD treatment nor pioglitazone alone or in combination affected clonic seizures. However, the latency to GTC seizures was dose-dependently and significantly increased by both KD (~57%, p < 0.05) and pioglitazone (~28%, p < 0.05). Coadministration of an ineffective 1:1 KD and pioglitazone resulted in ~47-55% (p < 0.05) increase in latency to GTC. Isobolographic analysis indicated a synergistic interaction of the KD and pioglitazone. SIGNIFICANCE These results suggest coadministration may enable reduction of the KD ratio without loss of seizure protection. Such adjuvant treatment could improve quality of life and limit adverse effects of a classic KD or high-dose pioglitazone.
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Affiliation(s)
- Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska, U.S.A
| | - Stephanie A Matthews
- Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska, U.S.A
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska, U.S.A
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Simeone TA, Matthews SA, Samson KK, Simeone KA. Regulation of brain PPARgamma2 contributes to ketogenic diet anti-seizure efficacy. Exp Neurol 2016; 287:54-64. [PMID: 27527983 DOI: 10.1016/j.expneurol.2016.08.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 08/05/2016] [Accepted: 08/11/2016] [Indexed: 12/23/2022]
Abstract
The ketogenic diet (KD) is an effective therapy primarily used in pediatric patients whom are refractory to current anti-seizure medications. The mechanism of the KD is not completely understood, but is thought to involve anti-inflammatory and anti-oxidant processes. The nutritionally-regulated transcription factor peroxisome proliferator activated receptor gamma, PPARγ, regulates genes involved in anti-inflammatory and anti-oxidant pathways. Moreover, endogenous ligands of PPARγ include fatty acids suggesting a potential role in the effects of the KD. Here, we tested the hypothesis that PPARγ contributes to the anti-seizure efficacy of the KD. We found that the KD increased nuclear protein content of the PPARγ2 splice variant by 2-4 fold (P<0.05) in brain homogenates from wild-type (WT) and epileptic Kv1.1 knockout (KO) mice, while not affecting PPARγ1. The KD reduced the frequency of seizures in Kv1.1KO mice by ~70% (P<0.01). GW9662, a PPARγ antagonist, prevented KD-mediated changes in PPARγ2 expression and prevented the anti-seizure efficacy of the KD in Kv1.1KO mice. Further supporting the association of PPARγ2 in mediating KD actions, the KD significantly prolonged the latency to flurothyl-induced seizure in WT mice by ~20-35% (P<0.01), but was ineffective in PPARγ2KO mice and neuron-specific PPARγKO mice. Finally, administering the PPARγ agonist pioglitazone increased PPARγ2 expression by 2-fold (P<0.01) and reduced seizures in Kv1.1KO mice by ~80% (P<0.01). Our findings implicate brain PPARγ2 among the mechanisms by which the KD reduces seizures and strongly support the development of PPARγ2 as a therapeutic target for severe, refractory epilepsy.
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Affiliation(s)
- Timothy A Simeone
- Creighton University, School of Medicine, Department of Pharmacology, Omaha, NE 68174, USA.
| | - Stephanie A Matthews
- Creighton University, School of Medicine, Department of Pharmacology, Omaha, NE 68174, USA
| | - Kaeli K Samson
- Creighton University, School of Medicine, Department of Pharmacology, Omaha, NE 68174, USA
| | - Kristina A Simeone
- Creighton University, School of Medicine, Department of Pharmacology, Omaha, NE 68174, USA
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