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McDouall A, Wassink G, Ranasinghe S, Zhou KQ, Karunasinghe RN, Dean JM, Davidson JO. Blockade of connexin hemichannels with tonabersat protects against mild hypoxic ischemic brain injury in neonatal rats. Exp Neurol 2024; 371:114611. [PMID: 37944882 DOI: 10.1016/j.expneurol.2023.114611] [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: 07/30/2023] [Revised: 10/15/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
BACKGROUND AND PURPOSE There is growing evidence that infants with mild hypoxic-ischemic (HI) encephalopathy have increased risk of brain injury and adverse neurodevelopmental outcomes. Currently, there is no approved treatment for these infants. It was previously shown that blocking connexin 43 hemichannels is neuroprotective in models of moderate to severe HI injury. However, it is yet to be established whether these channels play a role in the evolution of mild HI brain injury, and whether blocking these channels after mild HI is neuroprotective. METHODS HI was induced in postnatal day 10 rats of both sexes by right carotid artery ligation followed by 80 min of hypoxia in 8% oxygen. Pups receiving HI were randomised to receive intraperitoneal injections of either saline, vehicle (2-hydroxypropyl-beta-cyclodextrin polyethylene glycol-400), or tonabersat (2 mg/kg), at 60 min, 24 h, and 48 h after hypoxia. Seven days after HI, brains were harvested for measurement of volume loss and histological analysis. RESULTS HI resulted in a significant reduction in hemispheric, hippocampal, and white matter volumes, which were significantly attenuated after treatment with tonabersat. HI was also associated with a significant reduction in numbers of neurons in the CA1 and CA3 hippocampal regions, a reduction in the numbers of oligodendrocytes in the corpus callosum, and an increase in the number of astrocytes in both regions, which were significantly attenuated by tonabersat treatment. There were no differences in rectal temperatures between tonabersat- and vehicle-treated rat pups. CONCLUSIONS Blockade of connexin hemichannels with tonabersat significantly reduced mild HI injury in the hippocampus and white matter, without causing hypothermia.
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Affiliation(s)
- Alice McDouall
- Department of Physiology, the University of Auckland, New Zealand
| | - Guido Wassink
- Department of Physiology, the University of Auckland, New Zealand
| | | | - Kelly Q Zhou
- Department of Physiology, the University of Auckland, New Zealand
| | | | - Justin M Dean
- Department of Physiology, the University of Auckland, New Zealand
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Senger S, Fischer G, Mühl-Benninghaus R, Backens M, Reisel JR, Fritz T, Brack A, Reith W, Oertel J. Development and Evaluation of an MRI Artifact-Free Aneurysm Clip. Oper Neurosurg (Hagerstown) 2023:01787389-990000000-01002. [PMID: 38112448 DOI: 10.1227/ons.0000000000001031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/24/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND AND OBJECTIVES The digital subtraction angiography is still the gold standard in the follow-up after aneurysm surgery, although it remains a repeating invasive technique with accumulating X-ray exposure. An alternative magnetic resonance angiography has the disadvantage of metal-related artifacts. A metal-free aneurysm clip could overcome this problem. Recent advances in manufacturing technologies of fiber-reinforced plastics might allow developing a prototype of a metal-free clip. METHODS The prototype was formed out of carbon fiber-reinforced polyetheretherketone (CF-PEEK) in accordance with the standard clip design. In vivo and in vitro studies were performed to analyze the central nervous system biocompatibility. The prototype was tested in a phantom in a 3 T MRI scanner and microtomography scanner. For in vivo assessment, the left renal artery of rats was either ligated with a suture, clipped with a regular titanium clip or with the CF-PEEK prototype clip. The animals underwent standard MRI sequences and magnetic resonance angiography and assessment by a blinded neuroradiologist. RESULTS Phantom studies showed no signs of artifacts. The prototype showed a reliable clamping and reopening after clip application, although the clamping force was reduced. In vivo studies showed a successful occlusion of the renal artery in all cases in the magnetic resonance angiography. Clip artifacts were statistically significant reduced in the prototype group (P < .01). CF-PEEK showed no signs of impaired biocompatibility compared with the titanium samples in vitro and in vivo. CONCLUSION Former attempts of metal-free aneurysm clips did not meet the criteria of the standard clip design. In this study, the practicability of this new CF-PEEK artifact-free aneurysm clip has been proven. The further fabrication developments should overcome the problem of a reduced clamping force in the future. After clinical approval, it will improve the magnetic resonance image quality and might help to reduce the amount of digital subtraction angiography in the follow-up.
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Affiliation(s)
- Sebastian Senger
- Department of Neurosurgery, Medical School Saarland University, Homburg, Germany
| | - Gerrit Fischer
- Department of Neurosurgery, Medical School Saarland University, Homburg, Germany
| | | | - Martin Backens
- Department of Neuroradiology, Medical School Saarland University, Homburg, Germany
| | - Jan René Reisel
- Department of Neurosurgery, Medical School Saarland University, Homburg, Germany
| | - Tobias Fritz
- Department for Trauma, Hand and Reconstructive Surgery, Saarland University Medical Center, Homburg, Germany
| | - Alexander Brack
- Fraunhofer Institute for Production Technology IPT, Aachen, Germany
| | - Wolfgang Reith
- Department of Neuroradiology, Medical School Saarland University, Homburg, Germany
| | - Joachim Oertel
- Department of Neurosurgery, Medical School Saarland University, Homburg, Germany
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Xie Y, Yang Y, Yuan T. Brain Damage in the Preterm Infant: Clinical Aspects and Recent Progress in the Prevention and Treatment. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2023; 22:27-40. [PMID: 35209835 DOI: 10.2174/1871527321666220223092905] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/16/2022] [Accepted: 01/16/2022] [Indexed: 12/16/2022]
Abstract
Although the prevalence of brain injury and related neurodevelopmental disabilities resulting from preterm birth are major public health concerns, there are no definite neuroprotective strategies to prevent or reduce brain injury. The pattern of brain injury seen in preterm infants has evolved into more subtle lesions that are still essential to diagnose regarding neurodevelopmental outcomes. There is no specific effective method for the treatment of premature infant brain injury, and the focus of clinical treatment is still on prevention. Prevention of this injury requires insight into the pathogenesis, but many gaps exist in our understanding of how neonatal treatment procedures and medications impact cerebral hemodynamics and preterm brain injury. Many studies provide evidence about the prevention of premature infant brain injury, which is related to some drugs (such as erythropoietin, melatonin, mesenchymal stem cells, etc.). However, there are still some controversies about the quality of research and the effectiveness of therapy. This review aims to recapitulate the results of preclinical studies and provide an update on the latest developments around etiological pathways, prevention, and treatment.
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Affiliation(s)
- Yixuan Xie
- Department of Neonatology, Children\'s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, Zhejiang, P.R. China
| | - Yue Yang
- Department of Neonatology, Children\'s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, Zhejiang, P.R. China
| | - Tianming Yuan
- Department of Neonatology, Children\'s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, Zhejiang, P.R. China
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Zhou C, Wang J, Shao G, Xia X, Wu L, Yu A, Yang Z. Mild Hypothermia Protects Brain Injury After Intracerebral Hemorrhage in Mice Via Enhancing the Nrdp1/MyD88 Signaling Pathway. Neurotox Res 2022; 40:1664-1672. [PMID: 36125699 DOI: 10.1007/s12640-022-00576-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 08/02/2022] [Accepted: 08/29/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND Mild hypothermia has been identified to reduce brain injury following intracerebral hemorrhage (ICH) by protecting neuron cells through several pathways. However, the role of hypothermia in brain function following ICH and the related mechanisms have not been well identified. Ubiquitination-mediated inflammation plays important roles in the pathogenesis of immune diseases. The experiment analyzed anti-inflammatory effects of mild hypothermia following ICH. METHODS The model of ICH was induced by injecting autologous blood. Neuregulin receptor degradation protein-1 (Nrdp1) and downstream molecule were analyzed. In addition, brain inflammatory response, brain edema, and neurological functions of ICH mice were also assessed. RESULTS We found that mild hypothermia attenuated proinflammatory factors production after ICH. Mild hypothermia significantly inhibited BBB injury, water content, and neurological damage following ICH in vivo. Moreover, mild hypothermia also increased Nrdp1/MyD88 levels and thus affect neuronal apoptosis and inflammation. CONCLUSIONS Taken together, these results suggest that mild hypothermia can attenuate the neuroinflammatory response and neuronal apoptosis after ICH through the regulation of the Nrdp1 levels.
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Affiliation(s)
- Changlong Zhou
- Department of Neurosurgery, Yongchuan Hospital, Chongqing Medical University, Chongqing, 402160, China
| | - Jinping Wang
- Department of Neurology, Chongqing Emergency Medical Center, Chongqing University Central Hospital, Chongqing, 400014, China
| | - Gaohai Shao
- Department of Neurosurgery, Yongchuan Hospital, Chongqing Medical University, Chongqing, 402160, China
| | - Xiaohui Xia
- Department of Neurosurgery, Yongchuan Hospital, Chongqing Medical University, Chongqing, 402160, China
| | - Lirong Wu
- Department of Neurosurgery, Yongchuan Hospital, Chongqing Medical University, Chongqing, 402160, China
| | - Anyong Yu
- Department of Emergency, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, 563003, China.
| | - Zhao Yang
- Department of Neurosurgery, Yongchuan Hospital, Chongqing Medical University, Chongqing, 402160, China.
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Davidson JO, Gonzalez F, Gressens P, Gunn AJ. Update on mechanisms of the pathophysiology of neonatal encephalopathy. Semin Fetal Neonatal Med 2021; 26:101267. [PMID: 34274259 DOI: 10.1016/j.siny.2021.101267] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Therapeutic hypothermia is now well established to significantly improve survival without disability after neonatal encephalopathy (NE). To further improve outcomes, we need to better understand the mechanisms of brain injury. The central finding, which offers the potential for neuroprotective and neurorestorative interventions, is that brain damage after perinatal hypoxia-ischemia evolves slowly over time. Although brain cells may die during profound hypoxia-ischemia, even after surprisingly severe insults many cells show transient recovery of oxidative metabolism during a "latent" phase characterized by actively suppressed neural metabolism and activity. Critically, after moderate to severe hypoxia-ischemia, this transient recovery is followed after ~6 h by a phase of secondary deterioration, with delayed seizures, failure of mitochondrial function, cytotoxic edema, and cell death over ~72 h. This is followed by a tertiary phase of remodeling and recovery. This review discusses the mechanisms of injury that occur during the primary, latent, secondary and tertiary phases of injury and potential treatments that target one or more of these phases. By analogy with therapeutic hypothermia, treatment as early as possible in the latent phase is likely to have the greatest potential to prevent injury ("neuroprotection"). In the secondary phase of injury, anticonvulsants can attenuate seizures, but show limited neuroprotection. Encouragingly, there is now increasing preclinical evidence that late, neurorestorative interventions have potential to improve long-term outcomes.
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Affiliation(s)
- Joanne O Davidson
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
| | - Fernando Gonzalez
- Department of Pediatrics, University of California, San Francisco, CA, USA.
| | | | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
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Joseph A, Nyambura CW, Bondurant D, Corry K, Beebout D, Wood TR, Pfaendtner J, Nance E. Formulation and Efficacy of Catalase-Loaded Nanoparticles for the Treatment of Neonatal Hypoxic-Ischemic Encephalopathy. Pharmaceutics 2021; 13:1131. [PMID: 34452092 PMCID: PMC8400001 DOI: 10.3390/pharmaceutics13081131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 01/23/2023] Open
Abstract
Neonatal hypoxic-ischemic encephalopathy is the leading cause of permanent brain injury in term newborns and currently has no cure. Catalase, an antioxidant enzyme, is a promising therapeutic due to its ability to scavenge toxic reactive oxygen species and improve tissue oxygen status. However, upon in vivo administration, catalase is subject to a short half-life, rapid proteolytic degradation, immunogenicity, and an inability to penetrate the brain. Polymeric nanoparticles can improve pharmacokinetic properties of therapeutic cargo, although encapsulation of large proteins has been challenging. In this paper, we investigated hydrophobic ion pairing as a technique for increasing the hydrophobicity of catalase and driving its subsequent loading into a poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) nanoparticle. We found improved formation of catalase-hydrophobic ion complexes with dextran sulfate (DS) compared to sodium dodecyl sulfate (SDS) or taurocholic acid (TA). Molecular dynamics simulations in a model system demonstrated retention of native protein structure after complexation with DS, but not SDS or TA. Using DS-catalase complexes, we developed catalase-loaded PLGA-PEG nanoparticles and evaluated their efficacy in the Vannucci model of unilateral hypoxic-ischemic brain injury in postnatal day 10 rats. Catalase-loaded nanoparticles retained enzymatic activity for at least 24 h in serum-like conditions, distributed through injured brain tissue, and delivered a significant neuroprotective effect compared to saline and blank nanoparticle controls. These results encourage further investigation of catalase and PLGA-PEG nanoparticle-mediated drug delivery for the treatment of neonatal brain injury.
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Affiliation(s)
- Andrea Joseph
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA; (A.J.); (C.W.N.); (D.B.); (D.B.); (J.P.)
| | - Chris W. Nyambura
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA; (A.J.); (C.W.N.); (D.B.); (D.B.); (J.P.)
| | - Danielle Bondurant
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA; (A.J.); (C.W.N.); (D.B.); (D.B.); (J.P.)
| | - Kylie Corry
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA; (K.C.); (T.R.W.)
| | - Denise Beebout
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA; (A.J.); (C.W.N.); (D.B.); (D.B.); (J.P.)
| | - Thomas R. Wood
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA; (K.C.); (T.R.W.)
| | - Jim Pfaendtner
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA; (A.J.); (C.W.N.); (D.B.); (D.B.); (J.P.)
| | - Elizabeth Nance
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA; (A.J.); (C.W.N.); (D.B.); (D.B.); (J.P.)
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Zhou KQ, McDouall A, Drury PP, Lear CA, Cho KHT, Bennet L, Gunn AJ, Davidson JO. Treating Seizures after Hypoxic-Ischemic Encephalopathy-Current Controversies and Future Directions. Int J Mol Sci 2021; 22:ijms22137121. [PMID: 34281174 PMCID: PMC8268683 DOI: 10.3390/ijms22137121] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 12/20/2022] Open
Abstract
Seizures are common in newborn infants with hypoxic-ischemic encephalopathy and are highly associated with adverse neurodevelopmental outcomes. The impact of seizure activity on the developing brain and the most effective way to manage these seizures remain surprisingly poorly understood, particularly in the era of therapeutic hypothermia. Critically, the extent to which seizures exacerbate brain injury or merely reflect the underlying evolution of injury is unclear. Current anticonvulsants, such as phenobarbital and phenytoin have poor efficacy and preclinical studies suggest that most anticonvulsants are associated with adverse effects on the developing brain. Levetiracetam seems to have less potential neurotoxic effects than other anticonvulsants but may not be more effective. Given that therapeutic hypothermia itself has significant anticonvulsant effects, randomized controlled trials of anticonvulsants combined with therapeutic hypothermia, are required to properly determine the safety and efficacy of these drugs. Small clinical studies suggest that prophylactic phenobarbital administration may improve neurodevelopmental outcomes compared to delayed administration; however, larger high-quality studies are required to confirm this. In conclusion, there is a distinct lack of high-quality evidence for whether and to what extent neonatal seizures exacerbate brain damage after hypoxia-ischemia and how best to manage them in the era of therapeutic hypothermia.
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What is the Best Predictor of Phenobarbital Pharmacokinetics to Use for Initial Dosing in Neonates? Pharmaceutics 2021; 13:pharmaceutics13030301. [PMID: 33668911 PMCID: PMC7996486 DOI: 10.3390/pharmaceutics13030301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 02/21/2021] [Accepted: 02/22/2021] [Indexed: 11/17/2022] Open
Abstract
Phenobarbital is a first-line treatment of various seizure types in newborns. Dosage individualization maximizing the proportion of patients with drug levels in therapeutic range or sufficient treatment response is still challenging. The aim of this review was to summarize the available evidence on phenobarbital pharmacokinetics in neonates and to identify its possible covariates suitable for individualization of initial drug dosing. Several covariates have been considered: body weight and height, body surface area, gestational and postnatal age, laboratory parameters of renal and hepatic functions, asphyxia, therapeutic hypothermia, extracorporeal membrane oxygenation (ECMO), drug interactions, and genetic polymorphisms. The most frequently studied and well-founded covariate for the estimation of phenobarbital dosing is actual body weight. Loading dose of 15-20 mg/kg followed by a maintenance dose of 3-5 mg/kg/day seems to be accurate. However, the evidence for the other covariates with respect to dosing individualization is not sufficient. Doses at the lower limit of suggested range should be preferred in patients with severe asphyxia, while the upper limit of the range should be targeted in neonates receiving ECMO support.
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Wu Z, Xie C, Kuang H, Wu J, Chen X, Liu H, Liu T. Oxytocin mediates neuroprotection against hypoxic-ischemic injury in hippocampal CA1 neuron of neonatal rats. Neuropharmacology 2021; 187:108488. [PMID: 33556384 DOI: 10.1016/j.neuropharm.2021.108488] [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: 08/12/2020] [Revised: 01/26/2021] [Accepted: 01/31/2021] [Indexed: 12/13/2022]
Abstract
Neonatal hypoxic-ischemic encephalopathy (NHIE) is one of the most prevalent causes of death during the perinatal period. The lack of exposure to oxytocin is associated with NHIE-mediated severe brain injury. However, the underlying mechanism is not fully understood. This study combined immunohistochemistry with electrophysiological recordings of hippocampal CA1 neurons to investigate the role of oxytocin in an in vitro model of hypoxic-ischemic (HI) injury (oxygen and glucose deprivation, OGD) in postnatal day 7-10 rats. Immunohistochemical analysis showed that oxytocin largely reduced the relative intensity of TOPRO-3 staining following OGD in the hippocampal CA1 region. Whole-cell patch-clamp recording revealed that the OGD-induced onset time of anoxic depolarization (AD) was significantly delayed by oxytocin. This protective effect of oxytocin was blocked by pretreatment with [d(CH2)51, Tyr (Me)2, Thr4, Orn8, des-Gly-NH29] vasotocin (dVOT, an oxytocin receptor antagonist) or bicuculline (a GABAA receptor antagonist). Interestingly, oxytocin enhanced inhibitory postsynaptic currents in CA1 pyramidal neurons, which were abolished by tetrodotoxin or dVOT. In contrast, oxytocin had no effect on excitatory postsynaptic currents but induced an inward current in 86% of the pyramidal neurons tested. Taken together, these results demonstrate that oxytocin receptor signaling plays a critical role in attenuating neonatal neural death by facilitating GABAergic transmission, which may help to regulate the excitatory-inhibitory balance in local neuronal networks in NHIE patients.
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Affiliation(s)
- Zhihong Wu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, 17 St. Yongwaizheng, Nanchang, Jiangxi, 330006, PR China
| | - Changning Xie
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, 17 St. Yongwaizheng, Nanchang, Jiangxi, 330006, PR China
| | - Haixia Kuang
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, 17 St. Yongwaizheng, Nanchang, Jiangxi, 330006, PR China
| | - Jian Wu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, 17 St. Yongwaizheng, Nanchang, Jiangxi, 330006, PR China
| | - Xiao Chen
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, 17 St. Yongwaizheng, Nanchang, Jiangxi, 330006, PR China
| | - Huibao Liu
- Department of Pediatrics, Xinyu Maternal and Child Health Hospital, 292 S. Laodong, Xinyu, Jiangxi, 338025, PR China.
| | - Tao Liu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, 17 St. Yongwaizheng, Nanchang, Jiangxi, 330006, PR China.
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Adjunctive Neuroprotective Therapies for Treatment of Hypoxic-Ischemic Encephalopathy (HIE). CURRENT PEDIATRICS REPORTS 2020. [DOI: 10.1007/s40124-020-00231-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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High-Dose Melatonin and Ethanol Excipient Combined with Therapeutic Hypothermia in a Newborn Piglet Asphyxia Model. Sci Rep 2020; 10:3898. [PMID: 32127612 PMCID: PMC7054316 DOI: 10.1038/s41598-020-60858-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/17/2020] [Indexed: 01/13/2023] Open
Abstract
With the current practice of therapeutic hypothermia for neonatal encephalopathy, disability rates and the severity spectrum of cerebral palsy are reduced. Nevertheless, safe and effective adjunct therapies are needed to optimize outcomes. This study's objective was to assess if 18 mg/kg melatonin given rapidly over 2 h at 1 h after hypoxia-ischemia with cooling from 1-13 h was safe, achieved therapeutic levels within 3 h and augmented hypothermic neuroprotection. Following hypoxia-ischemia, 20 newborn piglets were randomized to: (i) Cooling 1-13 h (HT; n = 6); (ii) HT+ 2.5% ethanol vehicle (HT+V; n = 7); (iii) HT + Melatonin (HT+M; n = 7). Intensive care was maintained for 48 h; aEEG was acquired throughout, brain MRS acquired at 24 and 48 h and cell death (TUNEL) evaluated at 48 h. There were no differences for insult severity. Core temperature was higher in HT group for first hour after HI. Comparing HT+M to HT, aEEG scores recovered more quickly by 19 h (p < 0.05); comparing HT+V to HT, aEEG recovered from 31 h (p < 0.05). Brain phosphocreatine/inorganic phosphate and NTP/exchangeable phosphate were higher at 48 h in HT+M versus HT (p = 0.036, p = 0.049 respectively). Including both 24 h and 48 h measurements, the rise in Lactate/N-acetyl aspartate was reduced in white (p = 0.030) and grey matter (p = 0.038) after HI. Reduced overall TUNEL positive cells were observed in HT+M (47.1 cells/mm2) compared to HT (123.8 cells/mm2) (p = 0.0003) and HT+V (97.5 cells/mm2) compared to HT (p = 0.012). Localized protection was seen in white matter for HT+M versus HT (p = 0.036) and internal capsule for HT+M compared to HT (p = 0.001) and HT+V versus HT (p = 0.006). Therapeutic melatonin levels (15-30mg/l) were achieved at 2 h and were neuroprotective following HI, but ethanol vehicle was partially protective.
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Repurposing azithromycin for neonatal neuroprotection. Pediatr Res 2019; 86:444-451. [PMID: 31100754 PMCID: PMC6764891 DOI: 10.1038/s41390-019-0408-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 04/10/2019] [Accepted: 04/11/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Inflammation contributes to neonatal hypoxic-ischemic brain injury pathogenesis. We evaluated the neuroprotective efficacy of azithromycin, a safe, widely available antibiotic with anti-inflammatory properties, in a neonatal rodent hypoxic-ischemic brain injury model. METHODS Seven-day-old rats underwent right carotid artery ligation followed by 90-min 8% oxygen exposure; this procedure elicits quantifiable left forepaw functional impairment and right cerebral hemisphere damage. Sensorimotor function (vibrissae-stimulated forepaw placing, grip strength) and brain damage were compared in azithromycin- and saline-treated littermates 2-4 weeks later. Multiple treatment protocols were evaluated (variables included doses ranging from 15 to 45 mg/kg; treatment onset 15 min to 4 h post-hypoxia, and comparison of 1 vs. 3 injections). RESULTS All azithromycin doses improved function and reduced brain damage; efficacy was dose dependent, and declined with increasing treatment delay. Three azithromycin injections, administered over 48 h, improved performance on both function measures and reduced brain damage more than a single dose. CONCLUSION In this neonatal rodent model, azithromycin improved functional and neuropathology outcomes. If supported by confirmatory studies in complementary neonatal brain injury models, azithromycin could be an attractive candidate drug for repurposing and evaluation for neonatal neuroprotection in clinical trials.
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Martinello KA, Meehan C, Avdic-Belltheus A, Lingam I, Ragab S, Hristova M, Tann CJ, Peebles D, Hagberg H, Wolfs TGAM, Klein N, Tachtsidis I, Golay X, Kramer BW, Fleiss B, Gressens P, Robertson NJ. Acute LPS sensitization and continuous infusion exacerbates hypoxic brain injury in a piglet model of neonatal encephalopathy. Sci Rep 2019; 9:10184. [PMID: 31308390 PMCID: PMC6629658 DOI: 10.1038/s41598-019-46488-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 06/29/2019] [Indexed: 12/12/2022] Open
Abstract
Co-existing infection/inflammation and birth asphyxia potentiate the risk of developing neonatal encephalopathy (NE) and adverse outcome. In a newborn piglet model we assessed the effect of E. coli lipopolysaccharide (LPS) infusion started 4 h prior to and continued for 48 h after hypoxia on brain cell death and systemic haematological changes compared to LPS and hypoxia alone. LPS sensitized hypoxia resulted in an increase in mortality and in brain cell death (TUNEL positive cells) throughout the whole brain, and in the internal capsule, periventricular white matter and sensorimotor cortex. LPS alone did not increase brain cell death at 48 h, despite evidence of neuroinflammation, including the greatest increases in microglial proliferation, reactive astrocytosis and cleavage of caspase-3. LPS exposure caused splenic hypertrophy and platelet count suppression. The combination of LPS and hypoxia resulted in the highest and most sustained systemic white cell count increase. These findings highlight the significant contribution of acute inflammation sensitization prior to an asphyxial insult on NE illness severity.
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Affiliation(s)
- Kathryn A Martinello
- Institute for Women's Health, University College London, London, United Kingdom
- Robinson Research Institute, University of Adelaide, Adelaide, Australia
| | - Christopher Meehan
- Institute for Women's Health, University College London, London, United Kingdom
| | | | - Ingran Lingam
- Institute for Women's Health, University College London, London, United Kingdom
| | - Sara Ragab
- Institute for Women's Health, University College London, London, United Kingdom
| | - Mariya Hristova
- Institute for Women's Health, University College London, London, United Kingdom
| | - Cally J Tann
- Institute for Women's Health, University College London, London, United Kingdom
- Maternal, Adolescent, Reproductive and Child Health Centre, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Donald Peebles
- Institute for Women's Health, University College London, London, United Kingdom
| | - Henrik Hagberg
- Centre of Perinatal Medicine & Health, Department of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
- Centre for the Developing Brain, Department of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Tim G A M Wolfs
- Department of Paediatrics, University of Maastricht, Maastricht, Netherlands
| | - Nigel Klein
- Infection, Inflammation and Rheumatology, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Xavier Golay
- Institute of Neurology, University College London, London, United Kingdom
| | - Boris W Kramer
- Department of Paediatrics, University of Maastricht, Maastricht, Netherlands
| | - Bobbi Fleiss
- Centre for the Developing Brain, Department of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Pierre Gressens
- Centre for the Developing Brain, Department of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Nicola J Robertson
- Institute for Women's Health, University College London, London, United Kingdom.
- Division of Neonatology, Sidra Medicine, Doha, Qatar.
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14
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Davidson JO, Bennet L, Gunn AJ. Evaluating anti-epileptic drugs in the era of therapeutic hypothermia. Pediatr Res 2019; 85:931-933. [PMID: 30742031 DOI: 10.1038/s41390-019-0319-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 01/09/2019] [Accepted: 01/21/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Joanne O Davidson
- The Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
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15
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Quinlan SMM, Rodriguez-Alvarez N, Molloy EJ, Madden SF, Boylan GB, Henshall DC, Jimenez-Mateos EM. Complex spectrum of phenobarbital effects in a mouse model of neonatal hypoxia-induced seizures. Sci Rep 2018; 8:9986. [PMID: 29968748 PMCID: PMC6030182 DOI: 10.1038/s41598-018-28044-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/11/2018] [Indexed: 11/09/2022] Open
Abstract
Seizures in neonates, mainly caused by hypoxic-ischemic encephalopathy, are thought to be harmful to the brain. Phenobarbital remains the first line drug therapy for the treatment of suspected neonatal seizures but concerns remain with efficacy and safety. Here we explored the short- and long-term outcomes of phenobarbital treatment in a mouse model of hypoxia-induced neonatal seizures. Seizures were induced in P7 mice by exposure to 5% O2 for 15 minutes. Immediately after hypoxia, pups received a single dose of phenobarbital (25 mg.kg-1) or saline. We observed that after administration of phenobarbital seizure burden and number of seizures were reduced compared to the hypoxic period; however, PhB did not suppress acute histopathology. Behavioural analysis of mice at 5 weeks of age previously subjected to hypoxia-seizures revealed an increase in anxiety-like behaviour and impaired memory function compared to control littermates, and these effects were not normalized by phenobarbital. In a seizure susceptibility test, pups previously exposed to hypoxia, with or without phenobarbital, developed longer and more severe seizures in response to kainic acid injection compared to control mice. Unexpectedly, mice treated with phenobarbital developed less hippocampal damage after kainic acid than untreated counterparts. The present study suggests phenobarbital treatment in immature mice does not improve the long lasting functional deficits induces by hypoxia-induced seizures but, unexpectedly, may reduce neuronal death caused by exposure to a second seizure event in later life.
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Affiliation(s)
- Sean M M Quinlan
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland
| | - Natalia Rodriguez-Alvarez
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland
| | - Eleanor J Molloy
- Paediatrics, Academic Centre, Tallaght Hospital, Trinity College, The University of Dublin, Dublin, Ireland.,Neonatology, Coombe Women and Infants' University Hospital, Dublin, Ireland.,Neonatology, Our Lady's Children's Hospital Crumlin, Dublin, Ireland
| | - Stephen F Madden
- Data Science Centre, Beaux Lane House, Royal College of Surgeons in Ireland, Dublin, 2, Ireland
| | - Geraldine B Boylan
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland.,Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland.,Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland.
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16
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