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Lambert PM, Salvatore SV, Lu X, Shu HJ, Benz A, Rensing N, Yuede CM, Wong M, Zorumski CF, Mennerick S. A role for δ subunit-containing GABA A receptors on parvalbumin positive neurons in maintaining electrocortical signatures of sleep states. bioRxiv 2024:2024.03.25.586604. [PMID: 38585911 PMCID: PMC10996536 DOI: 10.1101/2024.03.25.586604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
GABA A receptors containing δ subunits have been shown to mediate tonic/slow inhibition in the CNS. These receptors are typically found extrasynaptically and are activated by relatively low levels of ambient GABA in the extracellular space. In the mouse neocortex, δ subunits are expressed on the surface of some pyramidal cells as well as on parvalbumin positive (PV+) interneurons. An important function of PV+ interneurons is the organization of coordinated network activity that can be measured by EEG; however, it remains unclear what role tonic/slow inhibitory control of PV+ neurons may play in shaping oscillatory activity. After confirming a loss of functional δ mediated tonic currents in PV cells in cortical slices from mice lacking Gabrd in PV+ neurons (PV δcKO), we performed EEG recordings to survey network activity across wake and sleep states. PV δcKO mice showed altered spectral content of EEG during NREM and REM sleep that was a result of increased oscillatory activity in NREM and the emergence of transient high amplitude bursts of theta frequency activity during REM. Viral reintroduction of Gabrd to PV+ interneurons in PV δcKO mice rescued REM EEG phenotypes, supporting an important role for δ subunit mediated inhibition of PV+ interneurons for maintaining normal REM cortical oscillations. Significance statement The impact on cortical EEG of inhibition on PV+ neurons was studied by deleting a GABA A receptor subunit selectively from these neurons. We discovered unexpected changes at low frequencies during sleep that were rescued by viral reintroduction.
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Foutz TJ, Rensing N, Han L, Durand DM, Wong M. Spatial and amplitude dynamics of neurostimulation: Insights from the acute intrahippocampal kainate seizure mouse model. Epilepsia Open 2024; 9:210-222. [PMID: 37926917 PMCID: PMC10839372 DOI: 10.1002/epi4.12861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/24/2023] [Indexed: 11/07/2023] Open
Abstract
OBJECTIVE Neurostimulation is an emerging treatment for patients with drug-resistant epilepsy, which is used to suppress, prevent, and terminate seizure activity. Unfortunately, after implantation and despite best clinical practice, most patients continue to have persistent seizures even after years of empirical optimization. The objective of this study is to determine optimal spatial and amplitude properties of neurostimulation in inhibiting epileptiform activity in an acute hippocampal seizure model. METHODS We performed high-throughput testing of high-frequency focal brain stimulation in the acute intrahippocampal kainic acid mouse model of status epilepticus. We evaluated combinations of six anatomic targets and three stimulus amplitudes. RESULTS We found that the spike-suppressive effects of high-frequency neurostimulation are highly dependent on the stimulation amplitude and location, with higher amplitude stimulation being significantly more effective. Epileptiform spiking activity was significantly reduced with ipsilateral 250 μA stimulation of the CA1 and CA3 hippocampal regions with 21.5% and 22.2% reductions, respectively. In contrast, we found that spiking frequency and amplitude significantly increased with stimulation of the ventral hippocampal commissure. We further found spatial differences with broader effects from CA1 versus CA3 stimulation. SIGNIFICANCE These findings demonstrate that the effects of therapeutic neurostimulation in an acute hippocampal seizure model are highly dependent on the location of stimulation and stimulus amplitude. We provide a platform to optimize the anti-seizure effects of neurostimulation, and demonstrate that an exploration of the large electrical parameter and location space can improve current modalities for treating epilepsy. PLAIN LANGUAGE SUMMARY In this study, we tested how electrical pulses in the brain can help control seizures in mice. We found that the electrode's placement and the stimulation amplitude had a large effect on outcomes. Some brain regions, notably nearby CA1 and CA3, responded positively with reduced seizure-like activities, while others showed increased activity. These findings emphasize that choosing the right spot for the electrode and adjusting the strength of electrical pulses are both crucial when considering neurostimulation treatments for epilepsy.
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Affiliation(s)
- Thomas J. Foutz
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Nicholas Rensing
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Lirong Han
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Dominique M. Durand
- Department of Biomedical EngineeringCase Western Reserve UniversityClevelandOhioUSA
| | - Michael Wong
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
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Tsuji S, Brace CS, Yao R, Tanie Y, Tada H, Rensing N, Mizuno S, Almunia J, Kong Y, Nakamura K, Furukawa T, Ogiso N, Toyokuni S, Takahashi S, Wong M, Imai SI, Satoh A. Sleep-wake patterns are altered with age, Prdm13 signaling in the DMH, and diet restriction in mice. Life Sci Alliance 2023; 6:e202301992. [PMID: 37045472 PMCID: PMC10105329 DOI: 10.26508/lsa.202301992] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/17/2023] [Accepted: 03/17/2023] [Indexed: 04/14/2023] Open
Abstract
Old animals display significant alterations in sleep-wake patterns such as increases in sleep fragmentation and sleep propensity. Here, we demonstrated that PR-domain containing protein 13 (Prdm13)+ neurons in the dorsomedial hypothalamus (DMH) are activated during sleep deprivation (SD) in young mice but not in old mice. Chemogenetic inhibition of Prdm13+ neurons in the DMH in young mice promotes increase in sleep attempts during SD, suggesting its involvement in sleep control. Furthermore, DMH-specific Prdm13-knockout (DMH-Prdm13-KO) mice recapitulated age-associated sleep alterations such as sleep fragmentation and increased sleep attempts during SD. These phenotypes were further exacerbated during aging, with increased adiposity and decreased physical activity, resulting in shortened lifespan. Dietary restriction (DR), a well-known anti-aging intervention in diverse organisms, ameliorated age-associated sleep fragmentation and increased sleep attempts during SD, whereas these effects of DR were abrogated in DMH-Prdm13-KO mice. Moreover, overexpression of Prdm13 in the DMH ameliorated increased sleep attempts during SD in old mice. Therefore, maintaining Prdm13 signaling in the DMH might play an important role to control sleep-wake patterns during aging.
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Affiliation(s)
- Shogo Tsuji
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology (NCGG), Obu, Japan
| | - Cynthia S Brace
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Ruiqing Yao
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology (NCGG), Obu, Japan
| | - Yoshitaka Tanie
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology (NCGG), Obu, Japan
| | - Hirobumi Tada
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology (NCGG), Obu, Japan
- Department of Nutrition, Faculty of Wellness, Shigakkan University, Obu, Japan
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Seiya Mizuno
- Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Japan
| | - Julio Almunia
- Laboratory of Experimental Animals, NCGG, Obu, Japan
| | - Yingyi Kong
- Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kazuhiro Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takahisa Furukawa
- Laboratories for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Noboru Ogiso
- Laboratory of Experimental Animals, NCGG, Obu, Japan
| | - Shinya Toyokuni
- Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Satoru Takahashi
- Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Japan
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Shin-Ichiro Imai
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Gerontology, Laboratory of Molecular Life Science, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Akiko Satoh
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology (NCGG), Obu, Japan
- Department of Integrative Physiology, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan
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Parhizkar S, Gent G, Chen Y, Rensing N, Gratuze M, Strout G, Sviben S, Tycksen E, Zhang Q, Gilmore PE, Sprung R, Malone J, Chen W, Remolina Serrano J, Bao X, Lee C, Wang C, Landsness E, Fitzpatrick J, Wong M, Townsend R, Colonna M, Schmidt RE, Holtzman DM. Sleep deprivation exacerbates microglial reactivity and Aβ deposition in a TREM2-dependent manner in mice. Sci Transl Med 2023; 15:eade6285. [PMID: 37099634 PMCID: PMC10449561 DOI: 10.1126/scitranslmed.ade6285] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 04/07/2023] [Indexed: 04/28/2023]
Abstract
Sleep loss is associated with cognitive decline in the aging population and is a risk factor for Alzheimer's disease (AD). Considering the crucial role of immunomodulating genes such as that encoding the triggering receptor expressed on myeloid cells type 2 (TREM2) in removing pathogenic amyloid-β (Aβ) plaques and regulating neurodegeneration in the brain, our aim was to investigate whether and how sleep loss influences microglial function in mice. We chronically sleep-deprived wild-type mice and the 5xFAD mouse model of cerebral amyloidosis, expressing either the humanized TREM2 common variant, the loss-of-function R47H AD-associated risk variant, or without TREM2 expression. Sleep deprivation not only enhanced TREM2-dependent Aβ plaque deposition compared with 5xFAD mice with normal sleeping patterns but also induced microglial reactivity that was independent of the presence of parenchymal Aβ plaques. We investigated lysosomal morphology using transmission electron microscopy and found abnormalities particularly in mice without Aβ plaques and also observed lysosomal maturation impairments in a TREM2-dependent manner in both microglia and neurons, suggesting that changes in sleep modified neuro-immune cross-talk. Unbiased transcriptome and proteome profiling provided mechanistic insights into functional pathways triggered by sleep deprivation that were unique to TREM2 and Aβ pathology and that converged on metabolic dyshomeostasis. Our findings highlight that sleep deprivation directly affects microglial reactivity, for which TREM2 is required, by altering the metabolic ability to cope with the energy demands of prolonged wakefulness, leading to further Aβ deposition, and underlines the importance of sleep modulation as a promising future therapeutic approach.
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Affiliation(s)
- Samira Parhizkar
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Grace Gent
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Yun Chen
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
- Department of Pathology and Immunology, Washington University, St. Louis, MO, USA
| | - Nicholas Rensing
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Maud Gratuze
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Gregory Strout
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO, USA
| | - Sanja Sviben
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO, USA
| | - Eric Tycksen
- Genome Technology Access Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Qiang Zhang
- Department of Medicine, Washington University Medical School, St. Louis, MO, USA
| | | | - Robert Sprung
- Department of Medicine, Washington University Medical School, St. Louis, MO, USA
| | - Jim Malone
- Department of Medicine, Washington University Medical School, St. Louis, MO, USA
| | - Wei Chen
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Javier Remolina Serrano
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Xin Bao
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Choonghee Lee
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Chanung Wang
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Eric Landsness
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - James Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO, USA
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Biomedical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Michael Wong
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Reid Townsend
- Department of Medicine, Washington University Medical School, St. Louis, MO, USA
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University, St. Louis, MO, USA
| | - Robert E Schmidt
- Department of Pathology and Immunology, Washington University, St. Louis, MO, USA
| | - David M Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
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Foutz TJ, Rensing N, Han L, Durand DM, Wong M. Spatial and Amplitude Dynamics of Neurostimulation: Insights from the Acute Intrahippocampal Kainate Seizure Mouse Model. bioRxiv 2023:2023.03.07.531440. [PMID: 36945383 PMCID: PMC10028881 DOI: 10.1101/2023.03.07.531440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Objective Neurostimulation is an emerging treatment for patients with medically refractory epilepsy, which is used to suppress, prevent, and terminate seizure activity. Unfortunately, after implantation and despite best clinical practice, most patients continue to have persistent seizures even after years of empirical optimization. The objective of this study is to determine optimal spatial and amplitude properties of neurostimulation in inhibiting epileptiform activity in an acute hippocampal seizure model. Methods We performed high-throughput testing of high-frequency focal brain stimulation in the acute intrahippocampal kainic acid mouse model of temporal lobe epilepsy. We evaluated combinations of six anatomic targets and three stimulus amplitudes. Results We found that the spike-suppressive effects of high-frequency neurostimulation are highly dependent on the stimulation amplitude and location, with higher amplitude stimulation being significantly more effective. Epileptiform spiking activity was significantly reduced with ipsilateral 250 μA stimulation of the CA1 and CA3 hippocampal regions with 21.5% and 22.2% reductions, respectively. In contrast, we found that spiking frequency and amplitude significantly increased with stimulation of the ventral hippocampal commissure. We further found spatial differences with broader effects from CA1 versus CA3 stimulation. Significance These findings demonstrate that the effects of therapeutic neurostimulation in an acute hippocampal seizure model are highly dependent on the location of stimulation and stimulus amplitude. We provide a platform to optimize the anti-seizure effects of neurostimulation, and demonstrate that an exploration of the large electrical parameter and location space can improve current modalities for treating epilepsy. Key Points Evaluated spatial and temporal parameters of neurostimulation in a mouse model of acute seizuresBrief bursts of high-frequency (100 Hz) stimulation effectively interrupted epileptiform activity.The suppressive effect was highly dependent on stimulation amplitude and was maximal at the ipsilateral CA1 and CA3 regions.Pro-excitatory effects were identified with high-amplitude high-frequency stimulation at the ventral hippocampal commissure and contralateral CA1.
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Johnson KJ, Moy B, Rensing N, Robinson A, Ly M, Chengalvala R, Wong M, Galindo R. Functional neuropathology of neonatal hypoxia-ischemia by single-mouse longitudinal electroencephalography. Epilepsia 2022; 63:3037-3050. [PMID: 36054439 PMCID: PMC10176800 DOI: 10.1111/epi.17403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/26/2022] [Accepted: 08/26/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Neonatal cerebral hypoxia-ischemia (HI) results in symptomatic seizures and long-term neurodevelopmental disability. The Rice-Vannucci model of rodent neonatal HI has been used extensively to examine and translate the functional consequences of acute and chronic HI-induced encephalopathy. Yet, longitudinal electrophysiological characterization of this brain injury model has been limited by the size of the neonatal mouse's head and postnatal maternal dependency. We overcome this challenge by employing a novel method of longitudinal single-mouse electroencephalography (EEG) using chronically implanted subcranial electrodes in the term-equivalent mouse pup. We characterize the neurophysiological disturbances occurring during awake and sleep states in the acute and chronic phases following newborn brain injury. METHODS C57BL/6 mice underwent long-term bilateral subcranial EEG and electromyographic electrode placement at postnatal day 9 followed by unilateral carotid cauterization and exposure to 40 minutes of hypoxia the following day. EEG recordings were obtained prior, during, and intermittently after the HI procedure from postnatal day 10 to weaning age. Quantitative EEG and fast Fourier transform analysis were used to evaluate seizures, cortical cerebral dysfunction, and disturbances in vigilance states. RESULTS We observed neonatal HI-provoked electrographic focal and bilateral seizures during or immediately following global hypoxia and most commonly contralateral to the ischemic injury. Spontaneous chronic seizures were not seen. Injured mice developed long-term asymmetric EEG background attenuation in all frequencies and most prominently during non-rapid eye movement (NREM) sleep. HI mice also showed transient impairments in vigilance state duration and transitions during the first 2 days following injury. SIGNIFICANCE The functional burden of mouse neonatal HI recorded by EEG resembles closely that of the injured human newborn. The use of single-mouse longitudinal EEG in this immature model can advance our understanding of the developmental and pathophysiological mechanisms of neonatal cerebral injury and help translate novel therapeutic strategies against this devastating condition.
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Affiliation(s)
- Kevin J Johnson
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Brianna Moy
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nicholas Rensing
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alexia Robinson
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael Ly
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Ramya Chengalvala
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael Wong
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rafael Galindo
- Department of Neurology, Division of Pediatric & Developmental Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
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Rensing N, Johnson KJ, Foutz TJ, Friedman JL, Galindo R, Wong M. Early developmental electroencephalography abnormalities, neonatal seizures, and induced spasms in a mouse model of tuberous sclerosis complex. Epilepsia 2020; 61:879-891. [PMID: 32274803 DOI: 10.1111/epi.16495] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Tuberous sclerosis complex (TSC) is one of the most common genetic causes of epilepsy. Seizures in TSC typically first present in infancy or early childhood, including focal seizures and infantile spasms. Infantile spasms in TSC are particularly characteristic in its strong responsiveness to vigabatrin. Although a number of mouse models of epilepsy in TSC have been described, there are very limited electroencephalographic (EEG) or seizure data during the preweanling neonatal and infantile-equivalent mouse periods. Tsc1GFAP CKO mice are a well-characterized mouse model of epilepsy in TSC, but whether these mice have seizures during early development has not been documented. The objective of this study was to determine whether preweanling Tsc1GFAP CKO mice have developmental EEG abnormalities or seizures, including spasms. METHODS Longitudinal video-EEG and electromyographic recordings were performed serially on Tsc1GFAP CKO and control mice from postnatal days 9-21 and analyzed for EEG background abnormalities, sleep-wake vigilance states, and spontaneous seizures. Spasms were also induced with varying doses of N-methyl-D-aspartate (NMDA). RESULTS The interictal EEG of Tsc1GFAP CKO mice had excessive discontinuity and slowing, suggesting a delayed developmental progression compared with control mice. Tsc1GFAP CKO mice also had increased vigilance state transitions and fragmentation. Tsc1GFAP CKO mice had spontaneous focal seizures in the early neonatal period and a reduced threshold for NMDA-induced spasms, but no spontaneous spasms were observed. SIGNIFICANCE Neonatal Tsc1GFAP CKO mice recapitulate early developmental aspects of EEG abnormalities, focal seizures, and an increased propensity for spasms. This mouse model may be useful for early mechanistic and therapeutic studies of epileptogenesis in TSC.
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Affiliation(s)
- Nicholas Rensing
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Kevin J Johnson
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Thomas J Foutz
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Joseph L Friedman
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Rafael Galindo
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Michael Wong
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
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Yoshida M, Satoh A, Lin JB, Mills KF, Sasaki Y, Rensing N, Wong M, Apte RS, Imai SI. Extracellular Vesicle-Contained eNAMPT Delays Aging and Extends Lifespan in Mice. Cell Metab 2019; 30:329-342.e5. [PMID: 31204283 PMCID: PMC6687560 DOI: 10.1016/j.cmet.2019.05.015] [Citation(s) in RCA: 213] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 03/02/2019] [Accepted: 05/17/2019] [Indexed: 01/07/2023]
Abstract
Aging is a significant risk factor for impaired tissue functions and chronic diseases. Age-associated decline in systemic NAD+ availability plays a critical role in regulating the aging process across many species. Here, we show that the circulating levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT) significantly decline with age in mice and humans. Increasing circulating eNAMPT levels in aged mice by adipose-tissue-specific overexpression of NAMPT increases NAD+ levels in multiple tissues, thereby enhancing their functions and extending healthspan in female mice. Interestingly, eNAMPT is carried in extracellular vesicles (EVs) through systemic circulation in mice and humans. EV-contained eNAMPT is internalized into cells and enhances NAD+ biosynthesis. Supplementing eNAMPT-containing EVs isolated from young mice significantly improves wheel-running activity and extends lifespan in aged mice. Our findings have revealed a novel EV-mediated delivery mechanism for eNAMPT, which promotes systemic NAD+ biosynthesis and counteracts aging, suggesting a potential avenue for anti-aging intervention in humans.
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Affiliation(s)
- Mitsukuni Yoshida
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA; MD-PhD Program, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Akiko Satoh
- Sleep and Aging Research Regulation Project Team, National Center for Geriatrics and Gerontology, Aichi, Japan
| | - Jonathan B Lin
- Department of Ophthalmology & Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; MD-PhD Program, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kathryn F Mills
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yo Sasaki
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rajendra S Apte
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Ophthalmology & Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shin-Ichiro Imai
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Gerontology, Laboratory of Molecular Life Science, Institute of Biomedical Research and Innovation, Kobe, Japan.
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Anastasaki C, Rensing N, Johnson KJ, Wong M, Gutmann DH. Neurofibromatosis type 1 (Nf1)-mutant mice exhibit increased sleep fragmentation. J Sleep Res 2019; 28:e12816. [PMID: 30609083 DOI: 10.1111/jsr.12816] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 11/21/2018] [Accepted: 11/22/2018] [Indexed: 12/16/2022]
Abstract
Neurofibromatosis type 1 (NF1) is a neurodevelopmental disorder in which affected children and adults are at a higher risk of sleep disorders. In an effort to identify potential sleep disturbances in a small animal model, we used a previously reported Nf1 conditional knockout (Nf1CKO ) mouse strain. In contrast to Nf1 mutant flies, the distribution of vigilance states was intact in Nf1CKO mice. However, Nf1CKO mice exhibited increased non-REM sleep (NREM)-to-wake and wake-to-NREM transitions. This sleep disruption was accompanied by decreased bout durations during awake and NREM sleep states under both light and dark conditions. Moreover, Nf1CKO mice have higher percentage delta power during awake and NREM sleep states under all light conditions. Taken together, Nf1CKO mice phenocopy some of the sleep disturbances observed in NF1 patients and provide a tractable platform to explore the molecular mechanisms governing sleep abnormalities in NF1.
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Affiliation(s)
- Corina Anastasaki
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | - Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | - Kevin J Johnson
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
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Cheng C, Deng PY, Ikeuchi Y, Yuede C, Li D, Rensing N, Huang J, Baldridge D, Maloney SE, Dougherty JD, Constantino J, Jahani-Asl A, Wong M, Wozniak DF, Wang T, Klyachko VA, Bonni A. Characterization of a Mouse Model of Börjeson-Forssman-Lehmann Syndrome. Cell Rep 2018; 25:1404-1414.e6. [PMID: 30403997 PMCID: PMC6261530 DOI: 10.1016/j.celrep.2018.10.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 09/18/2018] [Accepted: 10/11/2018] [Indexed: 01/10/2023] Open
Abstract
Mutations of the transcriptional regulator PHF6 cause the X-linked intellectual disability disorder Börjeson-Forssman-Lehmann syndrome (BFLS), but the pathogenesis of BFLS remains poorly understood. Here, we report a mouse model of BFLS, generated using a CRISPR-Cas9 approach, in which cysteine 99 within the PHD domain of PHF6 is replaced with phenylalanine (C99F). Mice harboring the patient-specific C99F mutation display deficits in cognitive functions, emotionality, and social behavior, as well as reduced threshold to seizures. Electrophysiological studies reveal that the intrinsic excitability of entorhinal cortical stellate neurons is increased in PHF6 C99F mice. Transcriptomic analysis of the cerebral cortex in C99F knockin mice and PHF6 knockout mice show that PHF6 promotes the expression of neurogenic genes and represses synaptic genes. PHF6-regulated genes are also overrepresented in gene signatures and modules that are deregulated in neurodevelopmental disorders of cognition. Our findings advance our understanding of the mechanisms underlying BFLS pathogenesis.
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Affiliation(s)
- Cheng Cheng
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Pan-Yue Deng
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110, USA
| | - Yoshiho Ikeuchi
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carla Yuede
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daofeng Li
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA
| | - Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ju Huang
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Dustin Baldridge
- Department of Pediatrics, Division of Newborn Medicine, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Susan E Maloney
- Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Joseph D Dougherty
- Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - John Constantino
- Department of Psychiatry, Division of Child Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Arezu Jahani-Asl
- Department of Oncology, Faculty of Medicine, McGill University, Montreal, QC H3T 1E2, Canada; Lady Davis Research Institute, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David F Wozniak
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Ting Wang
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA
| | - Vitaly A Klyachko
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110, USA
| | - Azad Bonni
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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11
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Rensing N, Moy B, Friedman JL, Galindo R, Wong M. Longitudinal analysis of developmental changes in electroencephalography patterns and sleep-wake states of the neonatal mouse. PLoS One 2018; 13:e0207031. [PMID: 30399187 PMCID: PMC6219806 DOI: 10.1371/journal.pone.0207031] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/23/2018] [Indexed: 11/19/2022] Open
Abstract
The neonatal brain undergoes rapid maturational changes that facilitate the normal development of the nervous system and also affect the pathological response to brain injury. Electroencephalography (EEG) and analysis of sleep-wake vigilance states provide important insights into the function of the normal and diseased immature brain. While developmental changes in EEG and vigilance states are well-described in people, less is known about the normal maturational properties of rodent EEG, including the emergence and evolution of sleep-awake vigilance states. In particular, a number of developmental EEG studies have been performed in rats, but there is limited comparable research in neonatal mice, especially as it pertains to longitudinal EEG studies performed within the same mouse. In this study, we have attempted to provide a relatively comprehensive assessment of developmental changes in EEG background activity and vigilance states in wild-type mice from postnatal days 9-21. A novel EEG and EMG method allowed serial recording from the same mouse pups. EEG continuity and power and vigilance states were analyzed by quantitative assessment and fast Fourier transforms. During this developmental period, we demonstrate the timing of maturational changes in EEG background continuity, frequencies, and power and the emergence of identifiable wake, NREM, and REM sleep states. These results should serve as important control data for physiological studies of mouse models of normal brain development and neurological disease.
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Affiliation(s)
- Nicholas Rensing
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Brianna Moy
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Joseph L. Friedman
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Rafael Galindo
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, United States of America
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12
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Heida KA, Waterman B, Tatro E, Bader J, McCoy AC, Rensing N, Orr J. Short-Term Perioperative Complications and Mortality After Total Ankle Arthroplasty in the United States. Foot Ankle Spec 2018; 11:123-132. [PMID: 28580856 DOI: 10.1177/1938640017709912] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED This study sought to identify patient and operative demographics associated with 30-day perioperative complications in patients undergoing total ankle arthroplasty as recorded in the National Surgical Quality Improvement Project database. Complications were divided into local and systemic and further subcategorized as major and minor. A total of 404 patients underwent total ankle arthroplasty between 2007 and 2014 as captured in the National Surgical Quality Improvement Project database. The overall complication rate was 2.4% with 0.5% mortality and 0.2% infection rate. Length of hospital stay, both as an end point at >5 days and as a continuous variable, was associated with overall complications (odds ratio [OR] = 9.90, P = .002 and OR = 1.52, P = .006, respectively). Patient characteristics that predicted perioperative morbidity included presence of 3 or comorbidities (OR = 8.48, P = 0.038), American Society of Anesthesiologists class III, and history of previous cardiac surgery (OR = 12.22, P = .033). Correct patient selection is imperative in achieving improved outcomes and those that are at risk for complications should be counseled as such. LEVELS OF EVIDENCE Level III: Database case control study.
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Affiliation(s)
- Kenneth A Heida
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
| | - Brian Waterman
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
| | - Eric Tatro
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
| | - Julia Bader
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
| | - Andrew C McCoy
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
| | - Nicholas Rensing
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
| | - Justin Orr
- William Beaumont Army Medical Center, El Paso, Texas.,Jackson Memorial Hospital, Miami, Florida (ACM)
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13
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Woodford MR, Sager RA, Marris E, Dunn DM, Blanden AR, Murphy RL, Rensing N, Shapiro O, Panaretou B, Prodromou C, Loh SN, Gutmann DH, Bourboulia D, Bratslavsky G, Wong M, Mollapour M. Tumor suppressor Tsc1 is a new Hsp90 co-chaperone that facilitates folding of kinase and non-kinase clients. EMBO J 2017; 36:3650-3665. [PMID: 29127155 PMCID: PMC5730846 DOI: 10.15252/embj.201796700] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 09/15/2017] [Accepted: 10/02/2017] [Indexed: 12/29/2022] Open
Abstract
The tumor suppressors Tsc1 and Tsc2 form the tuberous sclerosis complex (TSC), a regulator of mTOR activity. Tsc1 stabilizes Tsc2; however, the precise mechanism involved remains elusive. The molecular chaperone heat‐shock protein 90 (Hsp90) is an essential component of the cellular homeostatic machinery in eukaryotes. Here, we show that Tsc1 is a new co‐chaperone for Hsp90 that inhibits its ATPase activity. The C‐terminal domain of Tsc1 (998–1,164 aa) forms a homodimer and binds to both protomers of the Hsp90 middle domain. This ensures inhibition of both subunits of the Hsp90 dimer and prevents the activating co‐chaperone Aha1 from binding the middle domain of Hsp90. Conversely, phosphorylation of Aha1‐Y223 increases its affinity for Hsp90 and displaces Tsc1, thereby providing a mechanism for equilibrium between binding of these two co‐chaperones to Hsp90. Our findings establish an active role for Tsc1 as a facilitator of Hsp90‐mediated folding of kinase and non‐kinase clients—including Tsc2—thereby preventing their ubiquitination and proteasomal degradation.
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Affiliation(s)
- Mark R Woodford
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Rebecca A Sager
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Elijah Marris
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Diana M Dunn
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Adam R Blanden
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Ryan L Murphy
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Oleg Shapiro
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Barry Panaretou
- Institute of Pharmaceutical Science, King's College London, London, UK
| | | | - Stewart N Loh
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Dimitra Bourboulia
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Gennady Bratslavsky
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Mehdi Mollapour
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA .,Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY, USA.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
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Abstract
INTRODUCTION Historically, Achilles tendon repairs and other surgeries about the hindfoot have demonstrated a significantly higher rate of wound healing complications and surgical site morbidity. The purpose of this study was to evaluate the comprehensive complication profile and risk factors for adverse short-term, clinical outcomes after primary repair of Achilles tendon ruptures. METHODS Between the years 2005 and 2014, all cases of primary Achilles tendon repair (Current Procedural Terminology code 27650) entered into the National Surgical Quality Improvement Project (NSQIP) database were extracted for analysis. Primary outcomes of interest were rates of total complication, reoperation, and rerupture within 30 days of index surgery. Independent risk factors associated with these selected endpoints were assessed with chi-square and logistic regression analysis and odds ratios with 95% confidence intervals were used to express relative risk. RESULTS Of 1626 patients with an average age of 44 years (SD 13.3), the average ASA classification was 1.69 and hypertension (20.7%), morbid obesity (8.3%), and diabetes (4.9%) were among the most common medical comorbidities. A total of 28 (1.7%) patients sustained perioperative complications, including 1.3% with local complications (0.7% superficial wound infection, 0.4% wound disruption) and no cases of peripheral nerve injury or early repair failure. Systemic complications occurred in 0.4%, most commonly with deep venous thrombosis or nonfatal thromboembolism. Preoperative albumin was independently associated with an increased risk of local wound complications (odds ratio [OR] 28.67; 95% CI 1.42-579.40; P = .029). Chronic obstructive pulmonary disease (OR 22.33, 95% CI 2.49-199.81; P = .006) and bleeding disorder (OR 14.83, 95% CI 1.70-129.50; P = .015) were more likely to result in a systemic complication, and preoperative creatinine correlated with an increased risk of any complication (OR 6.11, 95% CI 1.15-32.34; P = .033). In total there were 5 (0.3%) readmissions with 2 (0.1%) unplanned reoperations attributed to local wound complications. CONCLUSION Among a broad-based demographic of the United States, the rate of local wound complications was exceedingly low in the short-term perioperative period, although this risk may be significantly magnified with subtle decreases in albumin levels. Preoperative risk stratifications should carefully scrutinize for subtle abnormalities in nutritional parameters and renal function prior to undergoing Achilles surgery. LEVELS OF EVIDENCE Therapeutic, Level II: Prospective, comparative trial.
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Affiliation(s)
- Nicholas Rensing
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas (NR, BRW, KAH, JDO).,Rush University Medical Center, Chicago, Illinois (RMF)
| | - Brian R Waterman
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas (NR, BRW, KAH, JDO).,Rush University Medical Center, Chicago, Illinois (RMF)
| | - Rachel M Frank
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas (NR, BRW, KAH, JDO).,Rush University Medical Center, Chicago, Illinois (RMF)
| | - Kenneth A Heida
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas (NR, BRW, KAH, JDO).,Rush University Medical Center, Chicago, Illinois (RMF)
| | - Justin D Orr
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas (NR, BRW, KAH, JDO).,Rush University Medical Center, Chicago, Illinois (RMF)
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15
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Abstract
Astrocytes play important roles in normal brain function and neurological diseases. In vivo two-photon excitation laser scanning microscopy has the potential to reveal rapid, dynamic structural changes in cells in a variety of physiological and pathological conditions. The type of in vivo imaging method has been shown to affect the plasticity of dendritic spines of neurons, but the optimal in vivo imaging methods of astrocytes have not been established. We compared open-skull and thinned-skull imaging methods for two-photon laser microscopy of live astrocytes in neocortex of GFAP-GFP transgenic mice. The thinned-skull method provided stable image intensity and morphological features of astrocytes in vivo over at least one week, with no evidence of astrogliosis. In contrast, the open-skull method resulted in significant changes in image intensity and induced astrogliosis. The thinned-skull method is the preferred approach for in vivo imaging of astrocytes under most conditions involving gross astrocyte modulation or causing astrogliosis.
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Affiliation(s)
- Dongjun Guo
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Jia Zou
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Nicholas Rensing
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States of America
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16
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Zhang B, Zou J, Han L, Rensing N, Wong M. Microglial activation during epileptogenesis in a mouse model of tuberous sclerosis complex. Epilepsia 2016; 57:1317-25. [PMID: 27263494 DOI: 10.1111/epi.13429] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2016] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Tuberous sclerosis complex (TSC) is a genetic disorder, characterized by tumor formation in multiple organs and severe neurologic manifestations, including epilepsy, intellectual disability, and autism. Abnormalities of both neurons and astrocytes have been implicated in contributing to the neurologic phenotype of TSC, but the role of microglia in TSC has not been investigated. The objectives of this study were to characterize microglial activation in a mouse model of TSC, involving conditional inactivation of the Tsc1 gene predominantly in glial cells (Tsc1(GFAP) CKO mice), and to test the hypothesis that microglial activation contributes to epileptogenesis in this mouse model. METHODS Microglial and astrocyte activation was examined in Tsc1(GFAP) CKO mice by ionized calcium binding adaptor molecule 1 and glial fibrillary acidic protein immunohistochemistry. Cytokine and chemokine expression was evaluated with quantitative polymerase chain reaction. Seizures were monitored by video-electroencephalography (EEG). The effect of minocycline in inhibiting microglial and astrocyte activation, cytokine expression, and seizures was tested. RESULTS Microglial cell number and size were increased in cortex and hippocampus of 3- to 4-week-old Tsc1(GFAP) CKO mice, which correlated with the onset of seizures. Minocycline treatment prevented the increase in number and cell size of microglia in 4-week-old Tsc1(GFAP) CKO mice. However, minocycline treatment had no effect on astrocyte proliferation and cytokine/chemokine expression and the progression of seizures in Tsc1(GFAP) CKO mice. SIGNIFICANCE Microglia cell number and size are abnormal in Tsc1(GFAP) CKO mice, and minocycline treatment inhibits this microglia activation, but does not suppress seizures. Microglia may play a role in the neurologic manifestations of TSC, but additional studies are needed in other models and human studies to determine whether microglia are critical for epileptogenesis in TSC.
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Affiliation(s)
- Bo Zhang
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Jia Zou
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Lirong Han
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Nicholas Rensing
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
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Abstract
BACKGROUND There are limited data evaluating the clinical outcomes of meniscal allograft transplantation (MAT) in physically active cohorts. PURPOSE To determine the survivorship, complication rates, and functional outcomes of MAT in an active military population. STUDY DESIGN Case series; Level of evidence, 4. METHODS All military patients undergoing MAT between 2007 and 2013 were identified from the Military Health System. Previous/concomitant procedures, perioperative complications, reoperation rate, revision, and initiation of medical discharge for persistent knee disability were recorded. Univariate analysis was performed to identify associations between patient-based and surgical variables on selected endpoints. RESULTS A total of 230 MATs (227 patients; 228 knees) were identified; the mean patient age was 27.2 years (range, 18-46 years), and the cohort was predominately male (89%). Approximately half (51%) of the patients had undergone prior, nonmeniscal knee procedures. Medial MATs were performed in 160 (69%) cases, and isolated MATs were most common (60%). A total of 51 complications occurred in 46 (21.1%) patients, including a secondary tear or extrusion (9%). At a mean clinical follow-up of 2.14 years, 10 (4.4%) patients required secondary meniscal debridement, while 1 (0.4%) patient required revision MAT and 2 (0.9%) patients underwent total knee arthroplasty. After MAT, 50 (22%) patients underwent knee-related military discharge at a mean of 2.49 years postoperatively. Tobacco use (P = .028) was associated with significantly increased risk of failure, and operation by fellowship-trained surgeons trended toward significance as a protective factor (P = .078). Furthermore, high-volume surgeons (≥1 MAT/year; range, 9-35) had significantly reduced rates of failure (P = .046). CONCLUSION While reporting low reoperation and revision rates, this investigation indicates that 22% of patients with MAT were unable to return to military duty due to persistent knee limitations at short-term follow-up. Increased surgical experience may decrease rates of failure after MAT. Careful patient selection and referral to subspecialty-trained, higher-volume surgeons should be considered to optimize clinical outcomes after MAT.
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Affiliation(s)
- Brian R Waterman
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas, USA
| | - Nicholas Rensing
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas, USA
| | - Kenneth L Cameron
- The John A. Feagin Jr Sports Medicine Fellowship, Keller Army Hospital, US Military Academy, West Point, New York, USA
| | - Brett D Owens
- The John A. Feagin Jr Sports Medicine Fellowship, Keller Army Hospital, US Military Academy, West Point, New York, USA
| | - Mark Pallis
- Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas, USA
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18
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Guo D, Zeng L, Zou J, Chen L, Rensing N, Wong M. Rapamycin prevents acute dendritic injury following seizures. Ann Clin Transl Neurol 2016; 3:180-90. [PMID: 27042678 PMCID: PMC4774262 DOI: 10.1002/acn3.284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/18/2015] [Indexed: 12/29/2022] Open
Abstract
Objective Seizures cause acute structural changes in dendrites, which may contribute to cognitive deficits that occur in epilepsy patients. Disruption of the actin cytoskeleton of dendrites likely mediates the structural changes following seizures, but the upstream signaling mechanisms activated by synchronized physiological activity to cause seizure‐induced dendritic injury are not known. In this study, we test the hypothesis that the mechanistic target of rapamycin complex 1 (mTORC1) pathway triggers structural changes in dendrites in response to seizures. Methods In vivo multiphoton imaging was performed in transgenic mice expressing green fluorescent protein in cortical neurons. The effect of rapamycin pre‐ and posttreatment was tested on kainate‐induced dendritic injury and cofilin‐mediated actin depolymerization. Results Kainate‐induced seizures caused acute activation of mTORC1 activity, which was prevented by the mTORC1 inhibitor, rapamycin. Rapamycin pretreatment, and to a lesser degree, posttreatment attenuated acute seizure‐induced dendritic injury and correspondingly decreased LIM kinase and cofilin‐mediated depolymerization of actin. Interpretation The mTORC1 pathway mediates seizure‐induced dendritic injury via depolymerization of actin. These findings have important mechanistic and translational applications for management of seizure‐induced brain injury.
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Affiliation(s)
- Dongjun Guo
- Department of Neurology and the Hope Center for Neurological Disorders Washington University School of Medicine St. Louis Missouri 63110
| | - Linghui Zeng
- Department of Pharmacy School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Jia Zou
- Department of Neurology and the Hope Center for Neurological Disorders Washington University School of Medicine St. Louis Missouri 63110
| | - Linglin Chen
- Department of Pharmacy School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Nicholas Rensing
- Department of Neurology and the Hope Center for Neurological Disorders Washington University School of Medicine St. Louis Missouri 63110
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders Washington University School of Medicine St. Louis Missouri 63110
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19
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Rensing N, Westermann A, Möller D, von Piekartz H. [Effects of Reactive Jump Training in Handball Players Regarding Jump Height and Power Development in the Triceps Surae Muscle]. Sportverletz Sportschaden 2015; 29:236-43. [PMID: 26579625 DOI: 10.1055/s-0041-106947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Studies have shown changes in the technical and physical demands in modern handball. The game has increased considerably in speed, power and dynamics. Jump training has, therefore, become ever more important in the training of the athletes. These developments contribute to the fact that handball is now one of the most injury-prone types of sport, with the lower extremities being most frequently affected. Reactive jump training is not only used in training by now, but also increasingly in injury prevention. The aim of this study was to investigate the effectiveness of reactive jump training with handball players. MATERIAL AND METHODS 21 regional league handball players were randomly divided into an intervention group (n = 12) and a control group (n = 9). The intervention group completed a six-week reactive jump training programme while the control group went through a non-specific training programme. Jump height (squat and counter movement jump), isokinetic and isometric maximum power as well as muscle activity served as measuring parameters. RESULTS A comparison of the intervention and control groups revealed that the reactive jump training led to significant improvements in jump height. The isometric and isokinetic maximum power measurements and the electromyographic activities of the triceps surae muscle demonstrated an improvement in the values within the intervention group. However, this improvement was not significant compared with the control group. Likewise both jumps correlated with the muscle activity of the soleus muscle as shown by electromyography. A moderate correlation was noticed between the isokinetic maximum power measurement and the electromyographic activity of the soleus and gastrocnemius medialis muscles. Furthermore, the correlations of the isometric and isokinetic maximum power meas-urements resulted in a strong correlation coefficient. CONCLUSION This study revealed a significant increase in jump height after reactive jump training. There was no significant difference in power development between the two groups. However, we were able to demonstrate correlations which would make it seem reasonable and interesting to investigate the question more closely. An interesting field of research could be the question of the effectiveness of reactive jump training in the areas of rehabilitation and injury prevention.
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Rensing N, Han L, Wong M. Intermittent dosing of rapamycin maintains antiepileptogenic effects in a mouse model of tuberous sclerosis complex. Epilepsia 2015; 56:1088-97. [PMID: 26122303 DOI: 10.1111/epi.13031] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2015] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Inhibitors of the mechanistic target of rapamycin (mTOR) pathway have antiepileptogenic effects in preventing epilepsy and pathologic and molecular mechanisms of epileptogenesis in mouse models of tuberous sclerosis complex (TSC). However, long-term treatment with mTOR inhibitors may be required to maintain efficacy and potentially has chronic side effects, such as immunosuppression. Attempts to minimize drug exposure will facilitate translational efforts to develop mTOR inhibitors as antiepileptogenic agents for patients with TSC. In this study, we tested intermittent dosing paradigms of mTOR inhibitors for antiepileptogenic properties in a TSC mouse model. METHODS Western blot analysis of phosphorylation of S6 protein was used to assess the dose- and time-dependence of mTOR inhibition by rapamycin in control mice and conditional knockout mice with inactivation of the Tsc1 gene in glial fibrillary acidic protein (GFAP)-expressing cells (Tsc1(GFAP)CKO mice). Based on the Western blot studies, different dosing paradigms of rapamycin starting at postnatal day 21 were tested for their ability to prevent epilepsy or pathologic abnormalities in Tsc1(GFAP)CKO mice: 4 days of rapamycin only (4-∞), 4 days on-24 days off (4-24), and 4 days on-10 days off (4-10). RESULTS mTOR activity was inhibited by rapamycin in a dose-dependent fashion and recovered to baseline by about 10 days after the last rapamycin dose. The 4-10 and 4-24 dosing paradigms almost completely prevented epilepsy and the 4-10 paradigm inhibited glial proliferation and megalencephaly in Tsc1(GFAP)CKO mice. SIGNIFICANCE Intermittent dosing of rapamycin, with drug holidays of more than 3 weeks, maintains significant antiepileptogenic properties in mouse models of TSC. These findings have important translational applications in developing mTOR inhibitors as antiepileptogenic agents in TSC patients by minimizing drug exposure and potential side effects.
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Affiliation(s)
- Nicholas Rensing
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Lirong Han
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, U.S.A
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Abstract
The effect of the ketogenic diet on behavior and cognition is unclear. We addressed this issue in rats behaviorally and electrophysiologically.We fed postnatal day 21 rats a standard diet (SD), ketogenic diet (KD), or calorie-restricted diet (CR) for 2–3 weeks. CR controlled for the slower weight gain experienced by KD-fed rats. We assessed behavioral performance with a locomotor activity and a conditioned fear test. To evaluate possible parallel effects of diet on synaptic function, we examined paired-pulse modulation (PPM) and long-term potentiation (LTP) in the medial perforant path in vivo. KD-fed rats performed similarly to SD-fed rats on the behavioral tests and electrophysiologic assays. These data suggest that the KD does not alter behavioral performance or synaptic plasticity.
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Affiliation(s)
- Liu Lin Thio
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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Rensing N, Balsara N, Wilhelm J, Eickelberg O, Königshoff M. Microarray analysis reveals NFIB as a potential target of the matricellular protein WISP1 in alveolar epithelial cells in idiopathic pulmonary fibrosis. Pneumologie 2009. [DOI: 10.1055/s-0029-1214116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Xu L, Rensing N, Yang XF, Zhang HX, Thio LL, Rothman SM, Weisenfeld AE, Wong M, Yamada KA. Leptin inhibits 4-aminopyridine- and pentylenetetrazole-induced seizures and AMPAR-mediated synaptic transmission in rodents. J Clin Invest 2008; 118:272-80. [PMID: 18097472 DOI: 10.1172/jci33009] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Accepted: 10/24/2007] [Indexed: 12/23/2022] Open
Abstract
Leptin is a hormone that reduces excitability in some hypothalamic neurons via leptin receptor activation of the JAK2 and PI3K intracellular signaling pathways. We hypothesized that leptin receptor activation in other neuronal subtypes would have anticonvulsant activity and that intranasal leptin delivery would be an effective route of administration. We tested leptin's anticonvulsant action in 2 rodent seizure models by directly injecting it into the cortex or by administering it intranasally. Focal seizures in rats were induced by neocortical injections of 4-aminopyridine, an inhibitor of voltage-gated K+ channels. These seizures were briefer and less frequent upon coinjection of 4-aminopyridine and leptin. In mice, intranasal administration of leptin produced elevated brain and serum leptin levels and delayed the onset of chemical convulsant pentylenetetrazole-induced generalized convulsive seizures. Leptin also reduced neuronal spiking in an in vitro seizure model. Leptin inhibited alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA) receptor-mediated synaptic transmission in mouse hippocampal slices but failed to inhibit synaptic responses in slices from leptin receptor-deficient db/db mice. JAK2 and PI3K antagonists prevented leptin inhibition of AMPAergic synaptic transmission. We conclude that leptin receptor activation and JAK2/PI3K signaling may be novel targets for anticonvulsant treatments. Intranasal leptin administration may have potential as an acute abortive treatment for convulsive seizures in emergency situations.
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Affiliation(s)
- Lin Xu
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Abstract
The ketogenic diet (KD) is an efficacious therapy for medically refractory childhood epilepsy that also slows weight gain. We tested the hypothesis that the KD slows weight gain via neurohormones involved in energy homeostasis. We found that juvenile rodents fed a KD had slower weight gain than those fed a standard diet (SD). Rats fed a KD had higher serum leptin levels and lower insulin levels compared with those fed an SD. We investigated the increase in leptin further because this change was the only one consistent with slower weight gain. Although rats fed the SD experienced slower weight gain when calorie restricted, they had serum leptin levels similar to those fed the SD ad libitum. Furthermore, leptin deficient (ob/ob) and leptin receptor deficient (db/db) mice did not show slower weight gain on the KD. All animals on the KD had elevated serum beta-hydroxybutyrate (betaHB) levels. Thus, ketosis is insufficient and a functioning leptin signaling system appears necessary for the KD to slow weight gain. The increase in leptin may contribute to the anticonvulsant effects of the KD.
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Affiliation(s)
- Liu Lin Thio
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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Yamada KA, Rensing N, Thio LL. Ketogenic diet reduces hypoglycemia-induced neuronal death in young rats. Neurosci Lett 2005; 385:210-4. [PMID: 15975714 DOI: 10.1016/j.neulet.2005.05.038] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 04/29/2005] [Accepted: 05/14/2005] [Indexed: 12/29/2022]
Abstract
Hypoglycemia is an important complication of insulin treatment in diabetic children and may contribute to lasting cognitive impairment. Previous studies demonstrated that 21-day-old rats (P21) subjected to brief, repetitive episodes of hypoglycemia sustain cortical neuronal death. The developing brain is capable of utilizing alternative energy substrates acetoacetate and beta-hydroxybutyrate. In these studies we tested the hypothesis that the developing brain adapted to ketone utilization and provided with ketones during hypoglycemia by eating a ketogenic diet would sustain less brain injury compared to littermates fed a standard diet. Supporting this hypothesis, P21 rats weaned to a ketogenic diet and subjected to insulin-induced hypoglycemia at P25 had significantly less neuronal death than rats on a standard diet. This animal model may provide insight into the determinants influencing the brain's susceptibility to hypoglycemic injury.
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Affiliation(s)
- Kelvin A Yamada
- Department of Neurology, Box 8111, Washington University School of Medicine, 660 South Euclid Ave, St Louis, MO 63110, USA.
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26
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Abstract
Epilepsy is associated with significant neurological morbidity, including learning disabilities, motor deficits, and behavioral problems. Although the causes of neurological dysfunction in epilepsy are multifactorial, accumulating evidence indicates that seizures in themselves may directly cause brain injury. Although it is clear that seizures can result in neuronal death, it is likely that under some circumstances seizures can induce more subtle functional or structural alterations in neurons. We induced focal neocortical seizures with 4-aminopyridine in transgenic mice expressing green fluorescent protein in cortical neurons and sequentially imaged individual dendrites in living animals with two-photon laser-scanning microscopy to determine whether these seizures caused acute alterations in dendritic spine morphology. No dendritic alterations were observed in anesthetized animals during electrographic seizures over a 3-hour period. Similarly, in unanesthetized mice, low-stage, clinical electrographic seizures had minimal effect on dendritic spines. More severe, high-stage seizures in unanesthetized mice were associated with a moderate loss of spines and dendritic swelling, but this effect may have been contingent on a synergistic action of phototoxicity from the imaging method itself. Overall, our results suggest that most neocortical seizures have minimal acute effects on dendrites over several hours, but may predispose to dendritic injury under extreme conditions.
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Affiliation(s)
- Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Abstract
Mechanisms underlying cognitive dysfunction in young diabetic children are poorly understood, and may include synaptic dysfunction from insulin-induced hypoglycemia. We developed a model of repetitive insulin-induced hypoglycemia in young rats and examined hippocampal long-term potentiation, an electrophysiologic assay of synaptic plasticity, 3-5 d after the last hypoglycemic event. Three hypoglycemic events between postnatal d 21-25 produced modest cortical (17 +/- 2.9 dead neurons per section in parasagittal cortex), but not hippocampal, neuron death quantified by Fluoro-Jade B staining. There was no change in neurogenesis in the hippocampal dentate granule cell region by quantification of bromodeoxyuridine incorporation. Although normal baseline hippocampal synaptic responses were elicited from hippocampal slices from hypoglycemic animals, long-term synaptic potentiation could not be induced in hippocampal slices from rats subjected to hypoglycemia. These results suggest that repetitive hypoglycemia in the developing brain can cause selective impairment of synaptic plasticity in the absence of cell death, and without complete disruption of basal synaptic transmission. We speculate that impaired synaptic plasticity in the hippocampus caused by repetitive hypoglycemia could underlie memory and cognitive deficits observed in young diabetic children, and that cortical neuron death caused by repetitive hypoglycemia in the developing brain may contribute to other neurologic, cognitive, and psychological problems sometimes encountered in diabetic children.
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Affiliation(s)
- Kelvin A Yamada
- Department of Neurology, Box 8111, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Schelo C, Kröger K, Hinrichs A, Rensing N, Rudofsky G. [Ischemia of the arm with finger necroses: differential carpal tunnel syndrome and thoracic outlet syndrome diagnosis]. VASA 1997; 26:311-3. [PMID: 9454458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Upper extremity ischemia with finger necrosis: carpal-tunnel syndrome or thoracic outlet syndrome? A 26-year-old male patient complained of pain paraesthesia in the right upper extremity while working with the arm elevated. After electrophysiological diagnosis of a carpal-tunnel-syndrome the patient received surgical treatment. Following this treatment he developed acral necrosis at the fingers. Additional diagnostic effort let to the diagnosis of a thoracic-outlet-syndrome due to a cervical rib. This case report and a review of the literature show that electrophysiological investigations alone can not differentiate the carpal-tunnel-syndrome from the thoracic-outlet-syndrome. Thus an operative release of a carpal-tunnel should not be performed until the arterial perfusion of the upper extremity has been judged.
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Affiliation(s)
- C Schelo
- Klinik für Angiologie, Universitätsklinikum Essen
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