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Sümer Coşkun A, Bülbül M, Çeker T, Özak A, Tanrıöver G, Elif Gürer İ, Tuzcu Balaban H, Göksu E, Aslan M. Protective Effects of Adropin in Experimental Subarachnoid Hemorrhage. Neuroscience 2024; 551:307-315. [PMID: 38851381 DOI: 10.1016/j.neuroscience.2024.05.037] [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: 03/21/2024] [Revised: 05/01/2024] [Accepted: 05/27/2024] [Indexed: 06/10/2024]
Abstract
PURPOSE We aimed to investigate early effects of exogenously administered adropin (AD) on neurological function, endothelial nitric oxide synthase (eNOS) expression, nitrite/nitrate levels, oxidative stress, and apoptosis in subarachnoid hemorrhage (SAH). METHODS Following intracerebroventricular AD administration (10 µg/5 µl at a rate of 1 µl/min) SAH model was carried out in Sprague-Dawley rats by injection of autologous blood into the prechiasmatic cistern. The effects of AD were assessed 24 h following SAH. The modified Garcia score was employed to evaluate functional insufficiencies. Adropin and caspase-3 proteins were measured by ELISA, while nitrite/nitrate levels, total antioxidant capacity (TAC) and reactive oxygen/nitrogen species (ROS/RNS) were assayed by standard kits. eNOS expression and apoptotic neurons were detected by immunohistochemical analysis. RESULTS The SAH group performed notably lower on the modified Garcia score compared to sham and SAH + AD groups. Adropin administration increased brain eNOS expression, nitrite/nitrate and AD levels compared to SHAM and SAH groups. SAH produced enhanced ROS/RNS generation and reduced antioxidant capacity in the brain. Adropin boosted brain TAC and diminished ROS/RNS production in SAH rats and no considerable change amongst SHAM and SAH + AD groups were detected. Apoptotic cells were notably increased in intensity and number after SAH and were reduced by AD administration. CONCLUSIONS Adropin increases eNOS expression and reduces neurobehavioral deficits, oxidative stress, and apoptotic cell death in SAH model. Presented results indicate that AD provides protection in early brain injury associated with SAH.
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Affiliation(s)
- Ayşenur Sümer Coşkun
- Division of Anesthesia and Reanimation, Kepez State Hospital, 07320 Antalya, Turkey.
| | - Mehmet Bülbül
- Department of Physiology, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - Tuğçe Çeker
- Department of Medical Biochemistry, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - Ahmet Özak
- Department of Neurosurgery, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - Gamze Tanrıöver
- Department of Histology, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - İnanç Elif Gürer
- Department Pathology, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - Hazal Tuzcu Balaban
- Department Pathology, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - Ethem Göksu
- Department of Neurosurgery, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
| | - Mutay Aslan
- Department of Medical Biochemistry, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey.
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Qian X, Zhang C, Zhou Z, Cao X, Zhang C, Chen T, Wang Y. Controlled decompression attenuates brain damage in a rat model of epidural extreme intracranial hypertension: Partially via inhibiting necroptosis and inflammatory response. Neurochem Int 2021; 153:105257. [PMID: 34952103 DOI: 10.1016/j.neuint.2021.105257] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 11/19/2022]
Abstract
Intracranial hypertension (IH) remains a common symptom of neurological diseases, and requires stepwise treatments to release intracranial pressure (ICP). In the present study, we built a rat model of epidural extreme intracranial hypertension (EEIH) and verified the effectiveness of a surgery method called controlled decompression on attenuating brain injury induced by EEIH. For the model part, we determined the level of EEIH of rats via recording ICP and cerebral perfusion pressure (CPP) and the variation tendency of survival rates, mean blood artery pressure and mean velocity (Vm) of left middle cerebral artery (LMCA) as ICP ascending. SD rats were assigned into 4 groups: Sham group, Controlled decompression group (Con group), Rapid decompression group (Rap group) and Rapid decompression + Necrostatin-1 (Nec-1) group (Rap+Nec-1 group). The results suggested that controlled decompression lowered cerebral water content, improved neurological function, and attenuated EEIH-induced inflammation response and ROS generation to a greater extent than rapid decompression. Meanwhile, controlled decompression functioned to preserve more Nissl bodies, indicating alleviated neuron injury after EEIH. Additionally, the permeability of blood brain barrier (BBB) was also safeguarded in the Con group. Western blotting (WB) and Real-time Polymerase Chain Reaction (rt-PCR) assays consistently determined lower protein and mRNA levels of necroptosis-related molecules receptor interacting protein kinase 1 (RIPK1), interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL) (WB only) in the Con and Rap+Nec-1 group. Double immunofluorescent staining found weaker fluorescence intensity of RIPK3 in the compressed cortex of the Con and Rap+Nec-1 group.
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Affiliation(s)
- Xiao Qian
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China
| | - Chonghui Zhang
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China
| | - Zhaopeng Zhou
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China
| | - Xinyi Cao
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China
| | - Chunlei Zhang
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China
| | - Tao Chen
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China.
| | - Yuhai Wang
- Department of Neurosurgery, The 904th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, Jiangsu, 214044, China.
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Oberdier MT, Antaki JF, Kharlamov A, Jones SC. Closed cranial window rodent model for investigating hemodynamic response to elevated intracranial pressure. Animal Model Exp Med 2021; 4:391-397. [PMID: 34977490 PMCID: PMC8690993 DOI: 10.1002/ame2.12187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 09/24/2021] [Accepted: 10/24/2021] [Indexed: 11/08/2022] Open
Abstract
Background Elevated intracranial pressure (ICP) occurs in several physiological and pathological conditions, yet long-term sequellae are not common, which implies that blood flow is preserved above ischemic thresholds. Methods This pilot study sought to confirm this hypothesis using a closed cranial window model in a rat in which ICP was elevated to 120 mmHg for 12 min, and superficial cortical perfusion was measured by laser Doppler flowmetry and laser speckle flowmetry. Results Following a transient increase, cortical blood flow decreased to between 25% and 75% of baseline. These levels correspond to disrupted metabolism and decreased protein synthesis but did not exceed thresholds for electrical signaling or membrane integrity. This may partially explain how some episodes of elevated ICP remain benign. Conclusion The closed cranial window model provides a platform for prospective study of physiologic responses to artificially elevated ICP during neurosurgery to promote hemostasis.
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Affiliation(s)
- Matt T. Oberdier
- Department of Biomedical EngineeringCarnegie Mellon UniversityPittsburghPennsylvaniaUSA
| | - James F. Antaki
- Department of Biomedical EngineeringCarnegie Mellon UniversityPittsburghPennsylvaniaUSA
| | - Alexander Kharlamov
- Department of AnesthesiologyAllegheny‐Singer Research InstitutePittsburghPennsylvaniaUSA
| | - Stephen C. Jones
- Department of AnesthesiologyAllegheny‐Singer Research InstitutePittsburghPennsylvaniaUSA
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Gu M, Mei XL, Zhao YN. Sepsis and Cerebral Dysfunction: BBB Damage, Neuroinflammation, Oxidative Stress, Apoptosis and Autophagy as Key Mediators and the Potential Therapeutic Approaches. Neurotox Res 2020; 39:489-503. [PMID: 32876918 DOI: 10.1007/s12640-020-00270-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023]
Abstract
Sepsis-associated cerebral dysfunction is complex pathophysiology, generated from primary infections that are developed elsewhere in the body. The neonates, elderly population and chronically ill and long-term hospitalized patients are predominantly vulnerable to sepsis and related cerebral damage. Generally, electrophysiological recordings, severity and sedation scales, computerized imaging and spectroscopy techniques are used for its detection and diagnosis. About the underlying mechanisms, enhanced blood-brain barrier permeability and metalloprotease activity, tight junction protein loss and endothelial cell degeneration promote the influx of inflammatory and toxic mediators into the brain, triggering cerebrovascular damage. An altered neutrophil count and phenotype further dysregulate the normal neuroimmune responses and neuroendocrine stability via modulated activation of protein kinase C-delta, nuclear factor kappa-B and sphingolipid signaling. Glial activation, together with pro-inflammatory cytokines and chemokines and the Toll-like receptor, destabilize the immune system. Moreover, superoxides and hydroperoxides generate oxidative stress and perturb mitochondrial dynamics and ATP synthesis, propagating neuronal injury cycle. Activated mitochondrial apoptotic pathway, characterized by increased caspase-3 and caspase-9 cleavage and Bax/Bcl2 ratio in the hippocampal and cortical neurons, stimulate neurocognitive impairments. Additionally, altered LC3-II/I and P62/SQSTM1, p-mTOR, p-AMPK1 and p-ULK1 levels and dysregulated autophagosome-lysosome fusion decrease neuronal and glial energy homeostasis. The therapies and procedures for attenuating sepsis-induced brain damage include early resuscitation, cerebral blood flow autoregulation, implantable electric vagus nerve stimulation, antioxidants, statins, glucocorticoids, neuroimmune axis modulators and PKCδ inhibitors. The current review enumerates the pathophysiology of sepsis-induced brain damage, its diagnosis, the role of critical inducers and mediators and, ultimately, therapeutic measures attenuating cerebrovascular degeneration.
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Affiliation(s)
- Ming Gu
- Department of Emergency and Critical Care Medicine, The Second Hospital of Jilin University, Changchun, China
| | - Xiang-Lin Mei
- Department of Pathology, The Second Hospital of Jilin University, Changchun, China
| | - Ya-Nan Zhao
- Neurology Department, China-Japan Union Hospital of Jilin University, Changchun, 130000, People's Republic of China.
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Zeiler FA, Beqiri E, Cabeleira M, Hutchinson PJ, Stocchetti N, Menon DK, Czosnyka M, Smielewski P, Ercole A. Brain Tissue Oxygen and Cerebrovascular Reactivity in Traumatic Brain Injury: A Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury Exploratory Analysis of Insult Burden. J Neurotrauma 2020; 37:1854-1863. [PMID: 32253987 PMCID: PMC7484893 DOI: 10.1089/neu.2020.7024] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Pressure reactivity index (PRx) and brain tissue oxygen (PbtO2) are associated with outcome in traumatic brain injury (TBI). This study explores the relationship between PRx and PbtO2 in adult moderate/severe TBI. Using the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) high resolution intensive care unit (ICU) sub-study cohort, we evaluated those patients with archived high-frequency digital intraparenchymal intracranial pressure (ICP) and PbtO2 monitoring data of, a minimum of 6 h in duration, and the presence of a 6 month Glasgow Outcome Scale -Extended (GOSE) score. Digital physiological signals were processed for ICP, PbtO2, and PRx, with the % time above/below defined thresholds determined. The duration of ICP, PbtO2, and PRx derangements was characterized. Associations with dichotomized 6-month GOSE (alive/dead, and favorable/unfavorable outcome; ≤ 4 = unfavorable), were assessed. A total of 43 patients were included. Severely impaired cerebrovascular reactivity was seen during elevated ICP and low PbtO2 episodes. However, most of the acute ICU physiological derangements were impaired cerebrovascular reactivity, not ICP elevations or low PbtO2 episodes. Low PbtO2 without PRx impairment was rarely seen. % time spent above PRx threshold was associated with mortality at 6 months for thresholds of 0 (area under the curve [AUC] 0.734, p = 0.003), > +0.25 (AUC 0.747, p = 0.002) and > +0.35 (AUC 0.745, p = 0.002). Similar relationships were not seen for % time with ICP >20 mm Hg, and PbtO2 < 20 mm Hg in this cohort. Extreme impairment in cerebrovascular reactivity is seen during concurrent episodes of elevated ICP and low PbtO2. However, the majority of the deranged cerebral physiology seen during the acute ICU phase is impairment in cerebrovascular reactivity, with most impairment occurring in the presence of normal PbtO2 levels. Measures of cerebrovascular reactivity appear to display the most consistent associations with global outcome in TBI, compared with ICP and PbtO2.
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Affiliation(s)
- Frederick A. Zeiler
- Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
- Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
- Centre on Aging, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Erta Beqiri
- Brain Physics Laboratory, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Manuel Cabeleira
- Brain Physics Laboratory, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Peter J. Hutchinson
- Department of Clinical Neurosciences, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Nino Stocchetti
- Neuro ICU Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Physiopathology and Transplantation, Milan University, Milan, Italy
| | - David K. Menon
- Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
- Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Ari Ercole
- Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
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Using computerized tomography perfusion to measure cerebral hemodynamics following treatment of traumatic brain injury in rabbits. Exp Ther Med 2019; 18:2104-2110. [PMID: 31410165 PMCID: PMC6676178 DOI: 10.3892/etm.2019.7785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 05/16/2019] [Indexed: 11/09/2022] Open
Abstract
The present study aimed to investigate the use of computerized tomography (CT) perfusion for evaluating cerebral hemodynamics following traumatic brain injury (TBI) in rabbits. The animals were randomly assigned into four groups (n=10 animals/group): i) Control, ii) TBI, iii) TBI + common decompression and iv) TBI + controlled decompression groups. A TBI model was established in rabbits using epidural balloon inflation. In the groups receiving intervention, animals were provided common decompression or controlled decompression treatments. Conventional CT and CT perfusion scanning were performed, with cerebral hemodynamic indices, including regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV) and mean transit time (MTT) being measured. Blood-brain barrier (BBB) permeability was evaluated using Evans blue staining. Compared with those in the control group, rCBF and rCBV values of the bilateral temporal lobes and basal ganglion in the TBI, TBI + common decompression and TBI + controlled decompression groups were significantly lower, whereas the MTT values were markedly prolonged and Evans blue dye content was greatly increased (P<0.01). Controlled decompression was demonstrated to be more potent than common decompression for preventing TBI-induced decline in rCBF and rCBV values in the bilateral temporal lobes and basal ganglion, as well as reversing TBI-induced extension of MTT in the bilateral temporal lobes (P<0.01 vs. TBI group). However, neither common nor controlled decompression could reduce TBI-induced increase in BBB permeability. In conclusion, these findings indicate that CT perfusion may be used to monitor cerebral hemodynamics following TBI in rabbits. Controlled decompression was deduced to be more potent than common decompression for preventing abnormalities in cerebral hemodynamics after TBI.
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Bragin DE, Statom GL, Nemoto EM. Induced Dynamic Intracranial Pressure and Cerebrovascular Reactivity Assessment of Cerebrovascular Autoregulation After Traumatic Brain Injury with High Intracranial Pressure in Rats. ACTA NEUROCHIRURGICA. SUPPLEMENT 2018; 126:309-312. [PMID: 29492580 DOI: 10.1007/978-3-319-65798-1_60] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE In previous work we showed that high intracranial pressure (ICP) in the rat brain induces a transition from capillary (CAP) to pathological microvascular shunt (MVS) flow, resulting in brain hypoxia, edema, and blood-brain barrier (BBB) damage. This transition was correlated with a loss of cerebral blood flow (CBF) autoregulation undetected by static autoregulatory curves but identified by induced dynamic ICP (iPRx) and cerebrovascular (iCVRx) reactivity. We hypothesized that loss of CBF autoregulation as correlated with MVS flow would be identified by iPRx and iCVRx in traumatic brain injury (TBI) with elevated ICP. METHODS TBI was induced by lateral fluid percussion (LFP) using a gas-driven device in rats. Using in vivo two-photon laser scanning microscopy, cortical microcirculation, tissue oxygenation (NADH autofluoresence), and BBB permeability (fluorescein dye extravasation) were measured before and for 4 h after TBI. Laser Doppler cortical flux, rectal and brain temperature, ICP and mean arterial pressure (MAP), blood gases, and electrolytes were monitored. Every 30 min, a transient 10 mmHg rise in MAP was induced by i.v. bolus of dopamine. iPRx = ΔICP/ΔMAP and iCVRx = ΔCBF/ΔMAP. RESULTS We demonstrated that iPRx and iCVRx correctly identified more severe loss of CBF autoregulation correlated with a transition of blood flow to MVS after TBI with high ICP compared to TBI without an increase in ICP. CONCLUSIONS In TBI with high ICP, high-velocity MVS flow is responsible for the loss of CBF autoregulation identified by iPRx and iCVRx.
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Affiliation(s)
- Denis E Bragin
- Department of Neurosurgery, University of New Mexico School of Medicine, University of New Mexico, Albuquerque, NM, USA.
| | - Gloria L Statom
- Department of Neurosurgery, University of New Mexico School of Medicine, University of New Mexico, Albuquerque, NM, USA
| | - Edwin M Nemoto
- Department of Neurosurgery, University of New Mexico School of Medicine, University of New Mexico, Albuquerque, NM, USA
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Bragin DE, Lara DA, Bragina OA, Kameneva MV, Nemoto EM. Resuscitation Fluid with Drag Reducing Polymer Enhances Cerebral Microcirculation and Tissue Oxygenation After Traumatic Brain Injury Complicated by Hemorrhagic Shock. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1072:39-43. [PMID: 30178321 PMCID: PMC6314472 DOI: 10.1007/978-3-319-91287-5_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Traumatic brain injury (TBI) is frequently accompanied by hemorrhagic shock (HS) which significantly worsens morbidity and mortality. Existing resuscitation fluids (RF) for volume expansion inadequately mitigate impaired microvascular cerebral blood flow (mvCBF) and hypoxia after TBI/HS. We hypothesized that nanomolar quantities of drag reducing polymers in resuscitation fluid (DRP-RF), would improve mvCBF by rheological modulation of hemodynamics. METHODS TBI was induced in rats by fluid percussion (1.5 atm, 50 ms) followed by controlled hemorrhage to a mean arterial pressure (MAP) = 40 mmHg. DRP-RF or lactated Ringer (LR-RF) was infused to MAP of 60 mmHg for 1 h (pre-hospital), followed by blood re-infusion to a MAP = 70 mmHg (hospital). Temperature, MAP, blood gases and electrolytes were monitored. In vivo 2-photon laser scanning microscopy was used to monitor microvascular blood flow, hypoxia (NADH) and necrosis (i.v. propidium iodide) for 5 h after TBI/HS followed by MRI for CBF and lesion volume. RESULTS TBI/HS compromised brain microvascular flow leading to capillary microthrombosis, tissue hypoxia and neuronal necrosis. DRP-RF compared to LR-RF reduced microthrombosis, restored collapsed capillary flow and improved mvCBF (82 ± 9.7% vs. 62 ± 9.7%, respectively, p < 0.05, n = 10). DRP-RF vs LR-RF decreased tissue hypoxia (77 ± 8.2% vs. 60 ± 10.5%, p < 0.05), and neuronal necrosis (21 ± 7.2% vs. 36 ± 7.3%, respectively, p < 0.05). MRI showed reduced lesion volumes with DRP-RF. CONCLUSIONS DRP-RF effectively restores mvCBF, reduces hypoxia and protects neurons compared to conventional volume expansion with LR-RF after TBI/HS.
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Affiliation(s)
- D E Bragin
- Department of Neurosurgery, University of New Mexico School of Medicine, Albuquerque, NM, USA.
| | - D A Lara
- Department of Neurosurgery, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - O A Bragina
- Department of Neurosurgery, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - M V Kameneva
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - E M Nemoto
- Department of Neurosurgery, University of New Mexico School of Medicine, Albuquerque, NM, USA
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Qaiser MZ, Dolman DEM, Begley DJ, Abbott NJ, Cazacu-Davidescu M, Corol DI, Fry JP. Uptake and metabolism of sulphated steroids by the blood-brain barrier in the adult male rat. J Neurochem 2017; 142:672-685. [PMID: 28665486 PMCID: PMC5601180 DOI: 10.1111/jnc.14117] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/21/2017] [Accepted: 06/26/2017] [Indexed: 01/08/2023]
Abstract
Little is known about the origin of the neuroactive steroids dehydroepiandrosterone sulphate (DHEAS) and pregnenolone sulphate (PregS) in the brain or of their subsequent metabolism. Using rat brain perfusion in situ, we have found 3H‐PregS to enter more rapidly than 3H‐DHEAS and both to undergo extensive (> 50%) desulphation within 0.5 min of uptake. Enzyme activity for the steroid sulphatase catalysing this deconjugation was enriched in the capillary fraction of the blood–brain barrier and its mRNA expressed in cultures of rat brain endothelial cells and astrocytes. Although permeability measurements suggested a net efflux, addition of the efflux inhibitors GF120918 and/or MK571 to the perfusate reduced rather than enhanced the uptake of 3H‐DHEAS and 3H‐PregS; a further reduction was seen upon the addition of unlabelled steroid sulphate, suggesting a saturable uptake transporter. Analysis of brain fractions after 0.5 min perfusion with the 3H‐steroid sulphates showed no further metabolism of PregS beyond the liberation of free steroid pregnenolone. By contrast, DHEAS underwent 17‐hydroxylation to form androstenediol in both the steroid sulphate and the free steroid fractions, with some additional formation of androstenedione in the latter. Our results indicate a gain of free steroid from circulating steroid sulphates as hormone precursors at the blood–brain barrier, with implications for ageing, neurogenesis, neuronal survival, learning and memory. ![]()
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Affiliation(s)
- M Zeeshan Qaiser
- Blood-Brain Barrier Research Group, Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Diana E M Dolman
- Blood-Brain Barrier Research Group, Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - David J Begley
- Blood-Brain Barrier Research Group, Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - N Joan Abbott
- Blood-Brain Barrier Research Group, Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Mihaela Cazacu-Davidescu
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
| | - Delia I Corol
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
| | - Jonathan P Fry
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
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Abstract
OBJECTIVES We recently showed that increased intracranial pressure to 50 mm Hg in the healthy rat brain results in microvascular shunt flow characterized by tissue hypoxia, edema, and increased blood-brain barrier permeability. We now determined whether increased intracranial pressure results in neuronal injury by Fluoro-Jade stain and whether changes in cerebral blood flow and cerebral metabolic rate for oxygen suggest nonnutritive microvascular shunt flow. DESIGN Intracranial pressure was elevated by a reservoir of artificial cerebrospinal fluid connected to the cisterna magna. Arterial blood gases, cerebral arterial-venous oxygen content difference, and cerebral blood flow by MRI were measured. Fluoro-Jade stain neurons were counted in histologic sections of the right and left dorsal and lateral cortices and hippocampus. SETTING University laboratory. SUBJECTS Male Sprague Dawley rats. INTERVENTIONS Arterial pressure support if needed by IV dopamine infusion and base deficit corrected by sodium bicarbonate. MEASUREMENTS AND MAIN RESULTS Fluoro-Jade stain neurons increased 2.5- and 5.5-fold at intracranial pressures of 30 and 50 mm Hg and cerebral perfusion pressures of 57 ± 4 (mean ± SEM) and 47 ± 6 mm Hg, respectively (p < 0.001) (highest in the right and left cortices). Voxel frequency histograms of cerebral blood flow showed a pattern consistent with microvascular shunt flow by dispersion to higher cerebral blood flow at high intracranial pressure and decreased cerebral metabolic rate for oxygen. CONCLUSIONS High intracranial pressure likely caused neuronal injury because of a transition from normal capillary flow to nonnutritive microvascular shunt flow resulting in tissue hypoxia and edema, and it is manifest by a reduction in the cerebral metabolic rate for oxygen.
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Arani A, Min HK, Fattahi N, Wetjen NM, Trzasko JD, Manduca A, Jack CR, Lee KH, Ehman RL, Huston J. Acute pressure changes in the brain are correlated with MR elastography stiffness measurements: initial feasibility in an in vivo large animal model. Magn Reson Med 2017; 79:1043-1051. [PMID: 28488326 PMCID: PMC5811891 DOI: 10.1002/mrm.26738] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/08/2017] [Accepted: 04/05/2017] [Indexed: 11/08/2022]
Abstract
PURPOSE The homeostasis of intracranial pressure (ICP) is of paramount importance for maintaining normal brain function. A noninvasive technique capable of making direct measurements of ICP currently does not exist. MR elastography (MRE) is capable of noninvasively measuring brain tissue stiffness in vivo, and may act as a surrogate to measure ICP. The objective of this study was to investigate the impact of changing ICP on brain stiffness using MRE in a swine model. METHODS Baseline MRE measurements were obtained, and then catheters were surgically placed into the left and right lateral ventricles of three animals. ICP was systematically increased over the range of 0 to 55 millimeters mercury (mmHg), and stiffness measurements were made using brain MRE at vibration frequencies of 60 hertz (Hz), 90 Hz, 120 Hz, and 150 Hz. RESULTS A significant linear correlation between stiffness and ICP in the cross-subject comparison was observed for all tested vibrational frequencies (P ≤ 0.01). The 120 Hz (0.030 ± 0.004 kilopascal (kPa)/mmHg, P < 0.0001) and 150 Hz (0.031 ± 0.008 kPa/mmHg, P = 0.01) vibrational frequencies had nearly identical slopes, which were approximately two- to three-fold higher than the 90 Hz (0.017 ± 0.002 kPa/mmHg, P < 0.0001) and 60 Hz (0.009 ± 0.002 kPa/mmHg, P = 0.001) slopes, respectively. CONCLUSION In this study, MRE demonstrated the potential for noninvasive measurement of changes in ICP. Magn Reson Med 79:1043-1051, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
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Affiliation(s)
- Arvin Arani
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Hoon-Ki Min
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.,Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Nikoo Fattahi
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Clifford R Jack
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Kendall H Lee
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Richard L Ehman
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - John Huston
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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12
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Donnelly J, Czosnyka M, Harland S, Varsos GV, Cardim D, Robba C, Liu X, Ainslie PN, Smielewski P. Cerebral haemodynamics during experimental intracranial hypertension. J Cereb Blood Flow Metab 2017; 37:694-705. [PMID: 26994043 PMCID: PMC5381462 DOI: 10.1177/0271678x16639060] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intracranial hypertension is a common final pathway in many acute neurological conditions. However, the cerebral haemodynamic response to acute intracranial hypertension is poorly understood. We assessed cerebral haemodynamics (arterial blood pressure, intracranial pressure, laser Doppler flowmetry, basilar artery Doppler flow velocity, and vascular wall tension) in 27 basilar artery-dependent rabbits during experimental (artificial CSF infusion) intracranial hypertension. From baseline (∼9 mmHg; SE 1.5) to moderate intracranial pressure (∼41 mmHg; SE 2.2), mean flow velocity remained unchanged (47 to 45 cm/s; p = 0.38), arterial blood pressure increased (88.8 to 94.2 mmHg; p < 0.01), whereas laser Doppler flowmetry and wall tension decreased (laser Doppler flowmetry 100 to 39.1% p < 0.001; wall tension 19.3 to 9.8 mmHg, p < 0.001). From moderate to high intracranial pressure (∼75 mmHg; SE 3.7), both mean flow velocity and laser Doppler flowmetry decreased (45 to 31.3 cm/s p < 0.001, laser Doppler flowmetry 39.1 to 13.3%, p < 0.001), arterial blood pressure increased still further (94.2 to 114.5 mmHg; p < 0.001), while wall tension was unchanged (9.7 to 9.6 mmHg; p = 0.35).This animal model of acute intracranial hypertension demonstrated two intracranial pressure-dependent cerebroprotective mechanisms: with moderate increases in intracranial pressure, wall tension decreased, and arterial blood pressure increased, while with severe increases in intracranial pressure, an arterial blood pressure increase predominated. Clinical monitoring of such phenomena could help individualise the management of neurocritical patients.
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Affiliation(s)
- Joseph Donnelly
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
| | - Marek Czosnyka
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK.,2 Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | | | - Georgios V Varsos
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
| | - Danilo Cardim
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
| | - Chiara Robba
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
| | - Xiuyun Liu
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
| | - Philip N Ainslie
- 4 Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, British Columbia, Canada
| | - Peter Smielewski
- 1 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
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