1
|
Uzay B, Bahadır-Varol A, Hökelekli FÖ, Yılmaz M, Esen EC, Başar K, Ayhan Y, Dalkara T, Eren-Koçak E. FGF2 gene's antisense protein, NUDT6, plays a depressogenic role by promoting inflammation and suppressing neurogenesis without altering FGF2 signalling. J Physiol 2024; 602:1427-1442. [PMID: 38468384 DOI: 10.1113/jp285479] [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: 08/14/2023] [Accepted: 02/21/2024] [Indexed: 03/13/2024] Open
Abstract
Fibroblast growth factor-2 (FGF2) is involved in the regulation of affective behaviour and shows antidepressant effects through the Akt and extracellular signal regulated kinase (ERK) 1/2 pathways. Nudix hydrolase 6 (NUDT6) protein is encoded from FGF2 gene's antisense strand and its role in the regulation of affective behaviour is unknown. Here, we overexpressed NUDT6 in the hippocampus and investigated its behavioural effects and the underlying molecular mechanisms affecting the behaviour. We showed that increasing hippocampal NUDT6 results in depression-like behaviour in rats without changing FGF2 levels or activating its downstream effectors, Akt and ERK1/2. Instead, NUDT6 acted by inducing inflammatory signalling, specifically by increasing S100 calcium binding protein A9 (S100A9) levels, activating nuclear factor-kappa B-p65 (NF-κB-p65), and elevating microglia numbers along with a reduction in neurogenesis. Our results suggest that NUDT6 could play a role in major depression by inducing a proinflammatory state. This is the first report of an antisense protein acting through a different mechanism of action than regulation of its sense protein. The opposite effects of NUDT6 and FGF2 on depression-like behaviour may serve as a mechanism to fine-tune affective behaviour. Our findings open up new venues for studying the differential regulation and functional interactions of sense and antisense proteins in neural function and behaviour, as well as in neuropsychiatric disorders. KEY POINTS: Hippocampal overexpression of nudix hydrolase 6 (NUDT6), the antisense protein of fibroblast growth factor-2 (FGF2), increases depression-like behaviour in rats. Hippocampal NUDT6 overexpression triggers a neuroinflammatory cascade by increasing S100 calcium binding proteinA9 (S100A9) expression and nuclear NF-κB-p65 translocation in neurons, in addition to microglial recruitment and activation. Hippocampal NUDT6 overexpression suppresses neurogenesis. NUDT6 exerts its actions without altering the levels or downstream signalling pathways of FGF2.
Collapse
Affiliation(s)
- Burak Uzay
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Brain Institute, Vanderbilt University, Nashville, Tennessee, United States
| | - Aslıhan Bahadır-Varol
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Fatma Özlem Hökelekli
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
- Department of Psychiatry, University of Texas Southwestern, Dallas, TX, USA
| | - Murat Yılmaz
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
- Department of Biology, Faculty of Science, Hacettepe University, Ankara, Turkey
| | - Emre Cem Esen
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Koray Başar
- Department of Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Yavuz Ayhan
- Department of Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Emine Eren-Koçak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
- Department of Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| |
Collapse
|
2
|
Kaya Z, Belder N, Sever-Bahcekapili M, Donmez-Demir B, Erdener ŞE, Bozbeyoglu N, Bagci C, Eren-Kocak E, Yemisci M, Karatas H, Erdemli E, Gursel I, Dalkara T. Vesicular HMGB1 release from neurons stressed with spreading depolarization enables confined inflammatory signaling to astrocytes. J Neuroinflammation 2023; 20:295. [PMID: 38082296 PMCID: PMC10712196 DOI: 10.1186/s12974-023-02977-6] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
The role of high mobility group box 1 (HMGB1) in inflammation is well characterized in the immune system and in response to tissue injury. More recently, HMGB1 was also shown to initiate an "inflammatory signaling cascade" in the brain parenchyma after a mild and brief disturbance, such as cortical spreading depolarization (CSD), leading to headache. Despite substantial evidence implying a role for inflammatory signaling in prevalent neuropsychiatric disorders such as migraine and depression, how HMGB1 is released from healthy neurons and how inflammatory signaling is initiated in the absence of apparent cell injury are not well characterized. We triggered a single cortical spreading depolarization by optogenetic stimulation or pinprick in naïve Swiss albino or transgenic Thy1-ChR2-YFP and hGFAP-GFP adult mice. We evaluated HMGB1 release in brain tissue sections prepared from these mice by immunofluorescent labeling and immunoelectron microscopy. EzColocalization and Costes thresholding algorithms were used to assess the colocalization of small extracellular vesicles (sEVs) carrying HMGB1 with astrocyte or microglia processes. sEVs were also isolated from the brain after CSD, and neuron-derived sEVs were captured by CD171 (L1CAM). sEVs were characterized with flow cytometry, scanning electron microscopy, nanoparticle tracking analysis, and Western blotting. We found that HMGB1 is released mainly within sEVs from the soma of stressed neurons, which are taken up by surrounding astrocyte processes. This creates conditions for selective communication between neurons and astrocytes bypassing microglia, as evidenced by activation of the proinflammatory transcription factor NF-ĸB p65 in astrocytes but not in microglia. Transmission immunoelectron microscopy data illustrated that HMGB1 was incorporated into sEVs through endosomal mechanisms. In conclusion, proinflammatory mediators released within sEVs can induce cell-specific inflammatory signaling in the brain without activating transmembrane receptors on other cells and causing overt inflammation.
Collapse
Affiliation(s)
- Zeynep Kaya
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Nevin Belder
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
- Biotechnology Institute, Ankara University, Ankara, Turkey
| | - Melike Sever-Bahcekapili
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Buket Donmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Şefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Naz Bozbeyoglu
- Department of Molecular Biology and Genetics, Science Faculty, Bilkent University, Ankara, Turkey
| | - Canan Bagci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
- Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Bahçeşehir University, Istanbul, Turkey
| | - Emine Eren-Kocak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Hulya Karatas
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Esra Erdemli
- Department of Histology and Embryology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Ihsan Gursel
- Department of Molecular Biology and Genetics, Science Faculty, Bilkent University, Ankara, Turkey
- Izmir Biomedicine and Genome Center, Dokuz Eylul University, İzmir, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey.
| |
Collapse
|
3
|
Dönmez-Demir B, Yemisci M, Uruk G, Söylemezoğlu F, Bolbos R, Kazmi S, Dalkara T. Cortical spreading depolarization-induced constriction of penetrating arteries can cause watershed ischemia: A potential mechanism for white matter lesions. J Cereb Blood Flow Metab 2023; 43:1951-1966. [PMID: 37435741 PMCID: PMC10676143 DOI: 10.1177/0271678x231186959] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 07/13/2023]
Abstract
Periventricular white matter lesions (WMLs) are common MRI findings in migraine with aura (MA). Although hemodynamic disadvantages of vascular supply to this region create vulnerability, the pathophysiological mechanisms causing WMLs are unclear. We hypothesize that prolonged oligemia, a consequence of cortical spreading depolarization (CSD) underlying migraine aura, may lead to ischemia/hypoxia at hemodynamically vulnerable watershed zones fed by long penetrating arteries (PAs). For this, we subjected mice to KCl-triggered single or multiple CSDs. We found that post-CSD oligemia was significantly deeper at medial compared to lateral cortical areas, which induced ischemic/hypoxic changes at watershed areas between the MCA/ACA, PCA/anterior choroidal and at the tip of superficial and deep PAs, as detected by histological and MRI examination of brains 2-4 weeks after CSD. BALB-C mice, in which MCA occlusion causes large infarcts due to deficient collaterals, exhibited more profound CSD-induced oligemia and were more vulnerable compared to Swiss mice such that a single CSD was sufficient to induce ischemic lesions at the tip of PAs. In conclusion, CSD-induced prolonged oligemia has potential to cause ischemic/hypoxic injury at hemodynamically vulnerable brain areas, which may be one of the mechanisms underlying WMLs located at the tip of medullary arteries seen in MA patients.
Collapse
Affiliation(s)
- Buket Dönmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Gökhan Uruk
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Figen Söylemezoğlu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Radu Bolbos
- CERMEP – imagerie du vivant, Groupement Hospitalier Est, Bron, France
| | - Shams Kazmi
- Biomedical Engineering Department, The University of Texas at Austin, Austin, Texas, USA
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
4
|
Erk EE, Demir BN, Kurşun HK, Özkan MY, Dalkara T, Koçak EE. The Effect of Inhibition of Perisynaptic Astrocyte Glycogen Utilization on Depression-Like Behavior. Turk Psikiyatri Derg 2023; 34:272-281. [PMID: 38173328 PMCID: PMC10786353 DOI: 10.5080/u27208] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 12/19/2022] [Indexed: 01/05/2024]
Abstract
OBJECTIVE Under physiological conditions, astrocytes produce lactate to meet the increased synaptic energy demand due to neuronal activity. In the light of the findings showing that this process is disrupted in the pathophysiology of major depression, the aim of this study is to investigate the effect of pharmacological inhibition of perisynaptic astrocyte glycogen utilization on anxiety-like behavior and depression-like behavior in female and male mice. METHODS In this study, DAB (1,4-dideoxy-1,4-imino-D-arabinitol), which is an inhibitor of glycogen breaking enzyme glycogen phosphorylase, was intrahippocampally administered to 15 female and 14 male Swiss albino mice, while 15 female and 12 male Swiss albino mice received intrahippocampal saline injections. Three and five days after the injections, the anxiety-like and depression-like behaviors of the mice were assessed by locomotor activity, open-field test, light-dark box test, tail suspension test and sucrose preference test. RESULTS Three days after injection, neither depression-like nor anxietylike significant behavioral changes were detected in the male experimental group mice compared to the control group; but an increase in locomotor activity (p=0.05) and time spent in the open-field (p=0.01) were observed on the fifth day. In evaluations of the female experimental group mice on the third and fifth days, depression-like and anxiety-like behaviors were found similar to the control group, as seen in the male mice. The only significant difference in the experimental group female mice was found in the sucrose preference test, which revealed an increased tendency to prefer sucrose (p=0.003) compared to the control group. CONCLUSION The inhibition of glycogen use in the hippocampus by DAB did not affect anxiety-like and depression-like behaviors 3 and 5 days after injection in both female and male mice. The increase in the time spent in the open-field by male experimental group mice was associated not with anxiety, but with increase in the locomotor activity. The fact that no significant difference was observed in the light-dark box test, which is another test used to evaluate anxiety, supported this opinion. The increase seen in the sucrose preference test in female experimental group mice was not interpreted as an increase in hedonic behavior because prevention of glycogen breakdown in the hypothalamus might have homeostatically increased sugar-craving and therefore resulted in an increase in sucrose preference. Different set of tests better targeting the energy and glucose metabolism and applied at farther time points than surgery are recommended for future studies.
Collapse
Affiliation(s)
- Erknaz Ecehan Erk
- DrHacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Buket Nebiye Demir
- Lecturer, Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Hülya Karataş Kurşun
- Prof., Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Müge Yemişçi Özkan
- Prof., Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Turgay Dalkara
- Prof., Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Emine Eren Koçak
- Prof., Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| |
Collapse
|
5
|
Hanalioglu S, Taskiran-Sag A, Karatas H, Donmez-Demir B, Yilmaz-Ozcan S, Eren-Kocak E, Gursoy-Ozdemir Y, Dalkara T. Cortical spreading depression can be triggered by sensory stimulation in primed wild type mouse brain: a mechanistic insight to migraine aura generation. J Headache Pain 2022; 23:107. [PMID: 35986251 PMCID: PMC9392331 DOI: 10.1186/s10194-022-01474-0] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/09/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Unlike the spontaneously appearing aura in migraineurs, experimentally, cortical spreading depression (CSD), the neurophysiological correlate of aura is induced by non-physiological stimuli. Consequently, neural mechanisms involved in spontaneous CSD generation, which may provide insight into how migraine starts in an otherwise healthy brain, remain largely unclear. We hypothesized that CSD can be physiologically induced by sensory stimulation in primed mouse brain.
Methods
Cortex was made susceptible to CSD with partial inhibition of Na+/K+-ATPase by epidural application of a low concentration of Na+/K+-ATPase blocker ouabain, allowing longer than 30-min intervals between CSDs or by knocking-down α2 subunit of Na+/K+-ATPase, which is crucial for K+ and glutamate re-uptake, with shRNA. Stimulation-triggered CSDs and extracellular K+ changes were monitored in vivo electrophysiologically and a K+-sensitive fluoroprobe (IPG-4), respectively.
Results
After priming with ouabain, photic stimulation significantly increased the CSD incidence compared with non-stimulated animals (44.0 vs. 4.9%, p < 0.001). Whisker stimulation also significantly increased the CSD incidence, albeit less effectively (14.9 vs. 2.4%, p = 0.02). Knocking-down Na+/K+-ATPase (50% decrease in mRNA) lowered the CSD threshold in all mice tested with KCl but triggered CSDs in 14.3% and 16.7% of mice with photic and whisker stimulation, respectively. Confirming Na+/K+-ATPase hypofunction, extracellular K+ significantly rose during sensory stimulation after ouabain or shRNA treatment unlike controls. In line with the higher CSD susceptibility observed, K+ rise was more prominent after ouabain. To gain insight to preventive mechanisms reducing the probability of stimulus-evoked CSDs, we applied an A1-receptor antagonist (DPCPX) to the occipital cortex, because adenosine formed during stimulation from ATP can reduce CSD susceptibility. DPCPX induced spontaneous CSDs but only small-DC shifts along with suppression of EEG spikes during photic stimulation, suggesting that the inhibition co-activated with sensory stimulation could limit CSD ignition when K+ uptake was not sufficiently suppressed as with ouabain.
Conclusions
Normal brain is well protected against CSD generation. For CSD to be ignited under physiological conditions, priming and predisposing factors are required as seen in migraine patients. Intense sensory stimulation has potential to trigger CSD when co-existing conditions bring extracellular K+ and glutamate concentrations over CSD-ignition threshold and stimulation-evoked inhibitory mechanisms are overcome.
Collapse
|
6
|
Bağcı C, Sever-Bahcekapili M, Belder N, Bennett APS, Erdener ŞE, Dalkara T. Overview of extracellular vesicle characterization techniques and introduction to combined reflectance and fluorescence confocal microscopy to distinguish extracellular vesicle subpopulations. Neurophotonics 2022; 9:021903. [PMID: 35386596 PMCID: PMC8978261 DOI: 10.1117/1.nph.9.2.021903] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 03/04/2022] [Indexed: 05/20/2023]
Abstract
Extracellular vesicles (EVs) are nanoparticles (30 to 1000 nm in diameter) surrounded by a lipid-bilayer which carry bioactive molecules between local and distal cells and participate in intercellular communication. Because of their small size and heterogenous nature they are challenging to characterize. Here, we discuss commonly used techniques that have been employed to yield information about EV size, concentration, mechanical properties, and protein content. These include dynamic light scattering, nanoparticle tracking analysis, flow cytometry, transmission electron microscopy, atomic force microscopy, western blotting, and optical methods including super-resolution microscopy. We also introduce an innovative technique for EV characterization which involves immobilizing EVs on a microscope slide before staining them with antibodies targeting EV proteins, then using the reflectance mode on a confocal microscope to locate the EV plane. By then switching to the microscope's fluorescence mode, immunostained EVs bearing specific proteins can be identified and the heterogeneity of an EV preparation can be determined. This approach does not require specialist equipment beyond the confocal microscopes that are available in many cell biology laboratories, and because of this, it could become a complementary approach alongside the aforementioned techniques to identify molecular heterogeneity in an EV preparation before subsequent analysis requiring specialist apparatus.
Collapse
Affiliation(s)
- Canan Bağcı
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
- Bahçeşehir University, Department of Biomedical Engineering, İstanbul, Turkey
| | | | - Nevin Belder
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
- Ankara University, Institute of Biotechnology, Ankara, Turkey
| | - Adam P. S. Bennett
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Şefik Evren Erdener
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
- Address all correspondence to Şefik Evren Erdener, ; Turgay Dalkara,
| | - Turgay Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
- Address all correspondence to Şefik Evren Erdener, ; Turgay Dalkara,
| |
Collapse
|
7
|
Abstract
Significance: Whether or not capillary pericytes contribute to blood flow regulation in the brain and retina has long been debated. This was partly caused by failure of detecting the contractile protein α -smooth muscle actin ( α -SMA) in capillary pericytes. Aim: The aim of this review is to summarize recent developments in detecting α -SMA and contractility in capillary pericytes and the relevant literature on the biology of actin filaments. Results: Evidence suggests that for visualization of the small amounts of α -SMA in downstream mid-capillary pericytes, actin depolymerization must be prevented during tissue processing. Actin filaments turnover is mainly based on de/re-polymerization rather than transcription of the monomeric form, hence, small amounts of α -SMA mRNA may evade detection by transcriptomic studies. Similarly, transgenic mice expressing fluorescent reporters under the α -SMA promoter may yield low fluorescence due to limited transcriptional activity in mid-capillary pericytes. Recent studies show that pericytes including mid-capillary ones express several actin isoforms and myosin heavy chain type 11, the partner of α -SMA in mediating contraction. Emerging evidence also suggests that actin polymerization in pericytes may have a role in regulating the tone of downstream capillaries. Conclusions: With guidance of actin biology, innovative labeling and imaging techniques can reveal the molecular machinery of contraction in pericytes.
Collapse
Affiliation(s)
- Şefik E. Erdener
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Gülce Küreli
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Turgay Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| |
Collapse
|
8
|
Cakir-Aktas C, Erdener SE, Teke B, Bozdag Pehlivan S, Zeybek ND, Taskiran-Sag A, Kaya Z, Dalkara T, Mut M. Confocal reflectance microscopy for metal and lipid nanoparticle visualization in the brain. Nanomedicine (Lond) 2022; 17:447-460. [PMID: 35142565 DOI: 10.2217/nnm-2021-0350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background: A requirement for nanoparticle (NP) research is visualization of particles within cells and tissues. Limitations of electron microscopy and low yields of NP fluorescent tagging warrant the identification of alternative imaging techniques. Method: Confocal reflectance microscopy (CRM) in combination with fluorescence imaging was assessed for visualizing rhodamine B-conjugated silver and fluorescein isothiocyanate-conjugated lipid core-stearylamine NP uptake in vitro and in vivo. Results: CRM successfully identified cellular uptake and blood-brain barrier penetration of NPs owing to their distinguishing refractive indices. NP-dependent reflectance signals in vitro were dose and incubation time dependent. Finally, CRM facilitated the distinction between nonspecific fluorescence signals and NPs. Conclusion: These findings demonstrate the value of CRM for NP visualization in tissues, which can be performed with a standard confocal microscope.
Collapse
Affiliation(s)
- Canan Cakir-Aktas
- Hacettepe University, Institute of Neurological Sciences & Psychiatry, Ankara, 06230, Turkey
| | - Sefik Evren Erdener
- Hacettepe University, Institute of Neurological Sciences & Psychiatry, Ankara, 06230, Turkey
| | - Büşra Teke
- Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, Ankara, 06230, Turkey
| | - Sibel Bozdag Pehlivan
- Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, Ankara, 06230, Turkey
| | - Naciye Dilara Zeybek
- Department of Histology & Embryology, Hacettepe University, Faculty of Medicine, Ankara, 06230, Turkey
| | - Aslihan Taskiran-Sag
- Hacettepe University, Institute of Neurological Sciences & Psychiatry, Ankara, 06230, Turkey
| | - Zeynep Kaya
- Hacettepe University, Institute of Neurological Sciences & Psychiatry, Ankara, 06230, Turkey
| | - Turgay Dalkara
- Hacettepe University, Institute of Neurological Sciences & Psychiatry, Ankara, 06230, Turkey
| | - Melike Mut
- Hacettepe University, Institute of Neurological Sciences & Psychiatry, Ankara, 06230, Turkey.,Department of Neurosurgery, Hacettepe University, Faculty of Medicine, Ankara, 06230, Turkey
| |
Collapse
|
9
|
Abstract
Migraine and major depression are debilitating disorders with high lifetime prevalence rates. Interestingly these disorders are highly comorbid and show significant heritability, suggesting shared pathophysiological mechanisms. Non-homeostatic function of ion channels and neuroinflammation may be common mechanisms underlying both disorders: The excitation-inhibition balance of microcircuits and their modulation by monoaminergic systems, which depend on the expression and function of membrane located K+, Na+, and Ca+2 channels, have been reported to be disturbed in both depression and migraine. Ion channels and energy supply to synapses not only change excitability of neurons but can also mediate the induction and maintenance of inflammatory signaling implicated in the pathophysiology of both disorders. In this respect, Pannexin-1 and P2X7 large-pore ion channel receptors can induce inflammasome formation that triggers release of pro-inflammatory mediators from the cell. Here, the role of ion channels involved in the regulation of excitation-inhibition balance, synaptic energy homeostasis as well as inflammatory signaling in migraine and depression will be reviewed.
Collapse
Affiliation(s)
- Emine Eren-Koçak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Psychiatry, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
10
|
Erdener ŞE, Kaya Z, Dalkara T. Parenchymal neuroinflammatory signaling and dural neurogenic inflammation in migraine. J Headache Pain 2021; 22:138. [PMID: 34794382 PMCID: PMC8600694 DOI: 10.1186/s10194-021-01353-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [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: 10/03/2021] [Accepted: 11/05/2021] [Indexed: 12/12/2022] Open
Abstract
Background Pain is generally concomitant with an inflammatory reaction at the site where the nociceptive fibers are activated. Rodent studies suggest that a sterile meningeal inflammatory signaling cascade may play a role in migraine headache as well. Experimental studies also suggest that a parenchymal inflammatory signaling cascade may report the non-homeostatic conditions in brain to the meninges to induce headache. However, how these signaling mechanisms function in patients is unclear and debated. Our aim is to discuss the role of inflammatory signaling in migraine pathophysiology in light of recent developments. Body Rodent studies suggest that a sterile meningeal inflammatory reaction can be initiated by release of peptides from active trigeminocervical C-fibers and stimulation of resident macrophages and dendritic/mast cells. This inflammatory reaction might be needed for sustained stimulation and sensitization of meningeal nociceptors after initial activation along with ganglionic and central mechanisms. Most migraines likely have cerebral origin as suggested by prodromal neurologic symptoms. Based on rodent studies, a parenchymal inflammatory signaling cascade has been proposed as a potential mechanism linking cortical spreading depolarization (CSD) to meningeal nociception. A recent PET/MRI study using a sensitive inflammation marker showed the presence of meningeal inflammatory activity in migraine with aura patients over the occipital cortex generating the visual aura. These studies also suggest the presence of a parenchymal inflammatory activity, supporting the experimental findings. In rodents, parenchymal inflammatory signaling has also been shown to be activated by migraine triggers such as sleep deprivation without requiring a CSD because of the resultant transcriptional changes, predisposing to inadequate synaptic energy supply during intense excitatory transmission. Thus, it may be hypothesized that neuronal stress created by either CSD or synaptic activity-energy mismatch could both initiate a parenchymal inflammatory signaling cascade, propagating to the meninges, where it is converted to a lasting headache with or without aura. Conclusion Experimental studies in animals and emerging imaging findings from patients warrant further research to gain deeper insight to the complex role of inflammatory signaling in headache generation in migraine.
Collapse
Affiliation(s)
- Şefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Zeynep Kaya
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sıhhiye, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, and Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
11
|
Dehghani A, Phisonkunkasem T, Yilmaz Ozcan S, Dalkara T, van den Maagdenberg AMJM, Tolner EA, Karatas H. Widespread brain parenchymal HMGB1 and NF-κB neuroinflammatory responses upon cortical spreading depolarization in familial hemiplegic migraine type 1 mice. Neurobiol Dis 2021; 156:105424. [PMID: 34118418 DOI: 10.1016/j.nbd.2021.105424] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 12/07/2020] [Revised: 04/04/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
Neuroinflammatory changes involving neuronal HMGB1 release and astrocytic NF-κB nuclear translocation occur following cortical spreading depolarization (CSD) in wildtype (WT) mice but it is unknown to what extent this occurs in the migraine brain. We therefore investigated in familial hemiplegic migraine type 1 (FHM1) knock-in mice, which express an intrinsic hyperexcitability phenotype, the extent of neuroinflammation without and after CSD. CSD was evoked in one hemisphere by pinprick (single CSD) or topical KCl application (multiple CSDs). Neuroinflammatory (HMGB1, NF-κB) and neuronal activation (pERK) markers were investigated by immunohistochemistry in the brains of WT and FHM1 mutant mice without and after CSD. Effects of NMDA receptor antagonism on basal and CSD-induced neuroinflammatory changes were examined by, respectively, systemically administered MK801 and ifenprodil or topical MK801 application. In FHM1 mutant mice, CSD caused enhanced neuronal HMGB1 release and astrocytic NF-κB nuclear translocation in the cortex and subcortical areas that were equally high in both hemispheres. In WT mice such effects were only pronounced in the hemisphere in which CSD was induced. Neuroinflammatory responses were associated with pERK expression indicating neuronal activation. Upon CSD, contralateral cortical and striatal HMGB1 release was reduced by topical application of MK801 in the hemisphere contralateral to the one in which CSD was induced. This study reveals that neuroinflammatory activation after CSD is widespread and extends to the contralateral hemisphere, particularly in brains of FHM1 mutant mice. Effective blockade of CSD-induced neuroinflammatory responses in the contralateral hemisphere in FHM1 mice by local NMDA receptor antagonism suggests that neuronal hyperexcitability-related neuroinflammation is relevant in migraine pathophysiology, but possibly also other neurological disorders in which spreading depolarization is involved.
Collapse
Affiliation(s)
- Anisa Dehghani
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands.
| | - Thas Phisonkunkasem
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Sinem Yilmaz Ozcan
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Arn M J M van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands; Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
| | - Else A Tolner
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands; Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
| | - Hulya Karatas
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
12
|
Abstract
The proper delivery of blood is essential for healthy neuronal function. The anatomical substrate for this precise mechanism is the neurovascular unit, which is formed by neurons, glial cells, endothelia, smooth muscle cells, and pericytes. Based on their particular location on the vessel wall, morphology, and protein expression, pericytes have been proposed as cells capable of regulating capillary blood flow. Pericytes are located around the microvessels, wrapping them with their processes. Their morphology and protein expression substantially vary along the vascular tree. Their contractibility is mediated by a unique cytoskeleton organization formed by filaments of actin that allows pericyte deformability with the consequent mechanical force transferred to the extracellular matrix for changing the diameter. Pericyte ultrastructure is characterized by large mitochondria likely to provide energy to regulate intracellular calcium concentration and fuel contraction. Accordingly, pericytes with compromised energy show a sustained intracellular calcium increase that leads to persistent microvascular constriction. Pericyte morphology is highly plastic and adapted for varying contractile capability along the microvascular tree, making pericytes ideal cells to regulate the capillary blood flow in response to local neuronal activity. Besides the vascular regulation, pericytes also play a role in the maintenance of the blood-brain/retina barrier, neovascularization and angiogenesis, and leukocyte transmigration. Here, we review the morphological and functional features of the pericytes as well as potential specific markers for the study of pericytes in the brain and retina.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, QC, Canada.
| | - Muge Yemisci
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
13
|
Petit JM, Eren-Koçak E, Karatas H, Magistretti P, Dalkara T. Brain glycogen metabolism: A possible link between sleep disturbances, headache and depression. Sleep Med Rev 2021; 59:101449. [PMID: 33618186 DOI: 10.1016/j.smrv.2021.101449] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 06/23/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/27/2022]
Abstract
The functions of sleep and its links with neuropsychiatric diseases have long been questioned. Among the numerous hypotheses on sleep function, early studies proposed that sleep helps to replenish glycogen stores consumed during waking. Later studies found increased brain glycogen after sleep deprivation, leading to "glycogenetic" hypothesis, which states that there is a parallel increase in synthesis and utilization of glycogen during wakefulness, whereas decrease in the excitatory transmission creates an imbalance causing accumulation of glycogen during sleep. Glycogen is a vital energy reservoir to match the synaptic demand particularly for re-uptake of potassium and glutamate during intense glutamatergic transmission. Therefore, sleep deprivation-induced transcriptional changes may trigger migraine by reducing glycogen availability, which slows clearance of extracellular potassium and glutamate, hence, creates susceptibility to cortical spreading depolarization, the electrophysiological correlate of migraine aura. Interestingly, chronic stress accompanied by increased glucocorticoid levels and locus coeruleus activity and leading to mood disorders in which sleep disturbances are prevalent, also affects brain glycogen turnover via glucocorticoids, noradrenaline, serotonin and adenosine. These observations altogether suggest that inadequate astrocytic glycogen turnover may be one of the mechanisms linking migraine, mood disorders and sleep.
Collapse
Affiliation(s)
- J-M Petit
- Lausanne University Hospital, Center for Psychiatric Neuroscience, Prilly, Switzerland.
| | - E Eren-Koçak
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, and Faculty of Medicine, Department of Psychiatry, Ankara, Turkey.
| | - H Karatas
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey.
| | - P Magistretti
- King Abdullah University of Science and Technology, Saudi Arabia.
| | - T Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey.
| |
Collapse
|
14
|
Kureli G, Yilmaz-Ozcan S, Erdener SE, Donmez-Demir B, Yemisci M, Karatas H, Dalkara T. F-actin polymerization contributes to pericyte contractility in retinal capillaries. Exp Neurol 2020; 332:113392. [DOI: 10.1016/j.expneurol.2020.113392] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/15/2020] [Accepted: 06/25/2020] [Indexed: 01/24/2023]
|
15
|
Taskiran-Sag A, Iversen NK, Gutiérrez-Jiménez E, Østergaard L, Dalkara T. Abstract WP326: Cortical Border Zones Are More Vulnerable to Spreading Depression-Induced Capillary Flow Disturbances. Stroke 2020. [DOI: 10.1161/str.51.suppl_1.wp326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cortical spreading depression (SD) is a major metabolic challenge to the brain and is followed by a unique hemodynamic response. It has been suggested that the oligemic phase of this response is accompanied by a mild to moderate capillary dysfunction. To test this hypothesis, we directly investigated microcirculatory flow changes during and after SD at the territory of major arteries as well as their hemodynamically vulnerable watershed zones. Swiss mice (n=6) under isoflurane anesthesia were tracheotomized, mechanically ventilated, and imaged under two-photon microscopy through a closed cranial window. Mean transit time (MTT), capillary transit time heterogeneity (CTH) and relative transit time heterogeneity (RTH) were calculated based on an indicator-dilution method using intravenous boluses of Texas-red dextran fluorescent dye (70,000 MW; 0.5%). Boluses were performed at the steady-state and 1 min, 5 min and 30 minutes after potassium chloride-induced SD. MTT, CTH, and RTH were estimated within the territory and border zone of major arteries to reveal any regional differences. Physiological parameters were monitored and kept within normal limits throughout the experiments. Both MTT and CTH increased following SD in the territorial zone from 1.07±0.03 to 1.67±0.15 s (mean±SEM;p<0.01) and from 0.51±0.03 to 0.94±0.07 s (mean±SEM;p<0.01), respectively. However, RTH was only mildly increased in this region from 0.49±0.04 to 0.59±0.06 (p=0.03). In the watershed area, all three parameters showed a more prominent increase following SD and RTH rose from 0.64±0.06 to 1.25±0.22 at 30 minutes (p=0.04). These findings provide direct experimental evidence for prolonged capillary flow disturbances induced by cortical SD, which may account for some lasting neurological symptoms after aura. The particular vulnerability of border zones to SD-induced flow disturbances may be involved in the pathogenesis of some of the white matter MRI lesions observed in migraineurs.
Collapse
Affiliation(s)
- Aslihan Taskiran-Sag
- Institute of Neurological Sciences and Psychiatry, Hacettepe Univ, Ankara, Turkey
| | - Nina Kerting Iversen
- Dept of Clinical Medicine, Cntr of Functionally Integrative Neuroscience (CFIN), Aarhus Univ, Aarhus, Denmark
| | - Eugenio Gutiérrez-Jiménez
- Dept of Clinical Medicine, Cntr of Functionally Integrative Neuroscience (CFIN), Aarhus Univ, Aarhus, Denmark
| | - Leif Østergaard
- Dept of Clinical Medicine, Cntr of Functionally Integrative Neuroscience (CFIN), Aarhus Univ, Aarhus, Denmark
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe Univ, Ankara, Turkey
| |
Collapse
|
16
|
Caban-Toktas S, Sahin A, Lule S, Esendagli G, Vural I, Karlı Oguz K, Soylemezoglu F, Mut M, Dalkara T, Khan M, Capan Y. Combination of Paclitaxel and R-flurbiprofen loaded PLGA nanoparticles suppresses glioblastoma growth on systemic administration. Int J Pharm 2020; 578:119076. [PMID: 31988035 DOI: 10.1016/j.ijpharm.2020.119076] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 08/12/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/22/2022]
Abstract
Malignant gliomas are highly lethal. Delivering chemotherapeutic drugs to the brain in sufficient concentration is the major limitation in their treatment due to the blood-brain barrier (BBB). Drug delivery systems may overcome this limitation and can improve the transportation through the BBB. Paclitaxel is an antimicrotubule agent with effective anticancer activity but limited BBB permeability. R-Flurbiprofen is a nonsteroidal antienflammatory drug and has potential anticancer activity. Accordingly, we designed an approach combining R-flurbiprofen and paclitaxel and positively-charged chitosan-modified poly-lactide-co-glycolic acid (PLGA) nanoparticles (NPs) and to transport them to glioma tissue. NPs were characterized and, cytotoxicity and cellular uptake studies were carried out in vitro. The in vivo efficacy of the combination and formulations were evaluated using a rat RG2 glioma tumor model. Polyethylene glycol (PEG) modified and chitosan-coated PLGA NPs demonstrated efficient cytotoxic activity and were internalized by the tumor cells in RG2 cell culture. In vivo studies showed that the chitosan-coated and PEGylated NPs loaded with paclitaxel and R-flurbiprofen exhibited significantly higher therapeutic activity against glioma. In conclusion, PLGA NPs can efficiently carry their payloads to glioma tissue and the combined use of anticancer and anti-inflammatory drugs may exert additional anti-tumor activity.
Collapse
Affiliation(s)
- Secil Caban-Toktas
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Adem Sahin
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Sevda Lule
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Gunes Esendagli
- Department of Basic Oncology, Hacettepe University Cancer Institute, Ankara, Turkey.
| | - Imran Vural
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey.
| | - Kader Karlı Oguz
- Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey; National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Figen Soylemezoglu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| | - Melike Mut
- Department of Neurosurgery, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| | - Turgay Dalkara
- Department of Neurology, Faculty of Medicine and Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| | - Mansoor Khan
- Texas A&M Health Science Center, Irma Lerma Rangel College of Pharmacy, Texas, USA.
| | - Yilmaz Capan
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
17
|
Karatas H, Yemisci M, Eren-Kocak E, Dalkara T. Brain Peptides for the Treatment of Neuropsychiatric Disorders. Curr Pharm Des 2019; 24:3905-3917. [PMID: 30417776 DOI: 10.2174/1381612824666181112112309] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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: 09/26/2018] [Revised: 10/28/2018] [Accepted: 11/05/2018] [Indexed: 11/22/2022]
Abstract
The realization of the importance of growth factors in adult CNS led to several studies investigating their roles in neuropsychiatric disorders. Based on the observations that chronic stress decreases brain-derived neurotrophic factor (BDNF) and antidepressant treatments reverse BDNF to normal levels, "neurotrophic hypothesis of depression" was proposed. Subsequent studies found that several other growth factors, including fibroblast growth factor (FGF), vascular endothelial growth factor, nerve growth factor were also decreased by chronic stress. Growth factors promote stem cell survival, angiogenesis and neurogenesis in addition to having anti-apoptotic and anti-inflammatory effects, all of which make them potential drug candidates as neuroprotective or neurorestorative agents. Indeed, certain peptides have consistently been shown to improve stroke outcome in experimental models of cerebral ischemia. Recent developments in nanotechnology appear promising in overcoming the blood-brain barrier and in delivering sufficient amounts of these large peptides to the brain after systemic administration. In addition to the translational potential resulting from application of nanotechnical approaches for delivering these large peptide growth factors, recent success obtained with small molecule and peptide antagonists of calcitonin gene-related peptide has created renewed enthusiasm to elucidate the role of neuropeptides in migraine headache, one of the most common health problems in the world. In this review, we will first focus on the role of FGF2 in mood disorders as well as in ischemic stroke. We will also introduce the nanomedicines developed to efficiently deliver FGF2 to the brain. In the last section, we will explore roles of the neuropeptides in migraine and its acute and prophylactic treatment.
Collapse
Affiliation(s)
- Hulya Karatas
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Emine Eren-Kocak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
18
|
Affiliation(s)
- Turgay Dalkara
- From the Department of Neurology, Faculty of Medicine and Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; and Department of Radiology, Massachusetts General Hospital, Harvard University, Boston
| |
Collapse
|
19
|
Alarcon-Martinez L, Yilmaz-Ozcan S, Yemisci M, Schallek J, Kılıç K, Villafranca-Baughman D, Can A, Di Polo A, Dalkara T. Retinal ischemia induces α-SMA-mediated capillary pericyte contraction coincident with perivascular glycogen depletion. Acta Neuropathol Commun 2019; 7:134. [PMID: 31429795 PMCID: PMC6701129 DOI: 10.1186/s40478-019-0761-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [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: 05/09/2019] [Accepted: 06/26/2019] [Indexed: 12/21/2022] Open
Abstract
Increasing evidence indicates that pericytes are vulnerable cells, playing pathophysiological roles in various neurodegenerative processes. Microvascular pericytes contract during cerebral and coronary ischemia and do not relax after re-opening of the occluded artery, causing incomplete reperfusion. However, the cellular mechanisms underlying ischemia-induced pericyte contraction, its delayed emergence, and whether it is pharmacologically reversible are unclear. Here, we investigate i) whether ischemia-induced pericyte contractions are mediated by alpha-smooth muscle actin (α-SMA), ii) the sources of calcium rise in ischemic pericytes, and iii) if peri-microvascular glycogen can support pericyte metabolism during ischemia. Thus, we examined pericyte contractility in response to retinal ischemia both in vivo, using adaptive optics scanning light ophthalmoscopy and, ex vivo, using an unbiased stereological approach. We found that microvascular constrictions were associated with increased calcium in pericytes as detected by a genetically encoded calcium indicator (NG2-GCaMP6) or a fluoroprobe (Fluo-4). Knocking down α-SMA expression with RNA interference or fixing F-actin with phalloidin or calcium antagonist amlodipine prevented constrictions, suggesting that constrictions resulted from calcium- and α-SMA-mediated pericyte contractions. Carbenoxolone or a Cx43-selective peptide blocker also reduced calcium rise, consistent with involvement of gap junction-mediated mechanisms in addition to voltage-gated calcium channels. Pericyte calcium increase and capillary constrictions became significant after 1 h of ischemia and were coincident with depletion of peri-microvascular glycogen, suggesting that glucose derived from glycogen granules could support pericyte metabolism and delay ischemia-induced microvascular dysfunction. Indeed, capillary constrictions emerged earlier when glycogen breakdown was pharmacologically inhibited. Constrictions persisted despite recanalization but were reversible with pericyte-relaxant adenosine administered during recanalization. Our study demonstrates that retinal ischemia, a common cause of blindness, induces α-SMA- and calcium-mediated persistent pericyte contraction, which can be delayed by glucose driven from peri-microvascular glycogen. These findings clarify the contractile nature of capillary pericytes and identify a novel metabolic collaboration between peri-microvascular end-feet and pericytes.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Sinem Yilmaz-Ozcan
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| | - Jesse Schallek
- Flaum Eye Institute and Center for Visual Science, University of Rochester, Rochester, New York, USA
| | - Kıvılcım Kılıç
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
| | - Deborah Villafranca-Baughman
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Alp Can
- Department of Histology and Embryology, School of Medicine, Ankara University, Ankara, Turkey
| | - Adriana Di Polo
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
20
|
Abstract
The cerebral microcirculation holds a critical position to match the high metabolic demand by neuronal activity. Functionally, microcirculation is virtually inseparable from other nervous system cells under both physiological and pathological conditions. For successful bench-to-bedside translation of neuroprotection research, the role of microcirculation in acute and chronic neurodegenerative disorders appears to be under-recognized, which may have contributed to clinical trial failures with some neuroprotectants. Increasing data over the last decade suggest that microcirculatory impairments such as endothelial or pericyte dysfunction, morphological irregularities in capillaries or frequent dynamic stalls in blood cell flux resulting in excessive heterogeneity in capillary transit may significantly compromise tissue oxygen availability. We now know that ischemia-induced persistent abnormalities in capillary flow negatively impact restoration of reperfusion after recanalization of occluded cerebral arteries. Similarly, microcirculatory impairments can accompany or even precede neural loss in animal models of several neurodegenerative disorders including Alzheimer's disease. Macrovessels are relatively easy to evaluate with radiological or experimental imaging methods but they cannot faithfully reflect the downstream microcirculatory disturbances, which may be quite heterogeneous across the tissue at microscopic scale and/or happen fast and transiently. The complexity and size of the elements of microcirculation, therefore, require utilization of cutting-edge imaging techniques with high spatiotemporal resolution as well as multidisciplinary team effort to disclose microvascular-neurodegenerative connection and to test treatment approaches to advance the field. Developments in two photon microscopy, ultrafast ultrasound, and optical coherence tomography provide valuable experimental tools to reveal those microscopic events with high resolution. Here, we review the up-to-date advances in understanding of the primary microcirculatory abnormalities that can result in neurodegenerative processes and the combined neurovascular protection approaches that can prevent acute as well as chronic neurodegeneration.
Collapse
Affiliation(s)
- Şefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| |
Collapse
|
21
|
Kilic K, Karatas H, Dönmez-Demir B, Eren-Kocak E, Gursoy-Ozdemir Y, Can A, Petit JM, Magistretti PJ, Dalkara T. Inadequate brain glycogen or sleep increases spreading depression susceptibility. Ann Neurol 2019; 83:61-73. [PMID: 29244233 DOI: 10.1002/ana.25122] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/23/2017] [Accepted: 12/12/2017] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Glycogen in astrocyte processes contributes to maintenance of low extracellular glutamate and K+ concentrations around excitatory synapses. Sleep deprivation (SD), a common migraine trigger, induces transcriptional changes in astrocytes, reducing glycogen breakdown. We hypothesize that when glycogen utilization cannot match synaptic energy demand, extracellular K+ can rise to levels that activate neuronal pannexin-1 channels and downstream inflammatory pathway, which might be one of the mechanisms initiating migraine headaches. METHODS We suppressed glycogen breakdown by inhibiting glycogen phosphorylation with 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and by SD. RESULTS DAB caused neuronal pannexin-1 large pore opening and activation of the downstream inflammatory pathway as shown by procaspase-1 cleavage and HMGB1 release from neurons. Six-hour SD induced pannexin-1 mRNA. DAB and SD also lowered the cortical spreading depression (CSD) induction threshold, which was reversed by glucose or lactate supplement, suggesting that glycogen-derived energy substrates are needed to prevent CSD generation. Supporting this, knocking down the neuronal lactate transporter MCT2 with an antisense oligonucleotide or inhibiting glucose transport from vessels to astrocytes with intracerebroventricularly delivered phloretin reduced the CSD threshold. In vivo recordings with a K+ -sensitive/selective fluoroprobe, Asante Potassium Green-4, revealed that DAB treatment or SD caused a significant rise in extracellular K+ during whisker stimulation, illustrating the critical role of glycogen in extracellular K+ clearance. INTERPRETATION Synaptic metabolic stress caused by insufficient glycogen-derived energy substrate supply can activate neuronal pannexin-1 channels as well as lower the CSD threshold. Therefore, conditions that limit energy supply to synapses (eg, SD) may predispose to migraine attacks, as suggested by genetic studies associating glucose or lactate transporter deficiency with migraine. Ann Neurol 2018;83:61-73.
Collapse
Affiliation(s)
- Kivilcim Kilic
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Hulya Karatas
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Buket Dönmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Emine Eren-Kocak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Yasemin Gursoy-Ozdemir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Current address for Dr Gursoy-Ozdemir: Department of Neurology, School of Medicine, Koç University, Istanbul, Turkey
| | - Alp Can
- Department of Histology and Embryology, School of Medicine, Ankara University, Ankara, Turkey
| | - Jean-Marie Petit
- Center for Psychiatric Neuroscience, Department of Psychiatry, University Hospital of the Canton of Vaud (CHUV), Prilly, Switzerland
| | - Pierre J Magistretti
- King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Brain Mind Institute, Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Turgay Dalkara
- Department of Neurology, Faculty of Medicine and Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
22
|
Dehghani A, Karatas H, Can A, Erdemli E, Yemisci M, Eren-Kocak E, Dalkara T. Nuclear expansion and pore opening are instant signs of neuronal hypoxia and can identify poorly fixed brains. Sci Rep 2018; 8:14770. [PMID: 30282977 PMCID: PMC6170374 DOI: 10.1038/s41598-018-32878-1] [Citation(s) in RCA: 3] [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: 05/25/2018] [Accepted: 09/11/2018] [Indexed: 11/09/2022] Open
Abstract
The initial phase of neuronal death is not well characterized. Here, we show that expansion of the nuclear membrane without losing its integrity along with peripheralization of chromatin are immediate signs of neuronal injury. Importantly, these changes can be identified with commonly used nuclear stains and used as markers of poor perfusion-fixation. Although frozen sections are widely used, no markers are available to ensure that the observed changes were not confounded by perfusion-induced hypoxia/ischemia. Moreover, HMGB1 was immediately released and p53 translocated to mitochondria in hypoxic/ischemic neurons, whereas nuclear pore complex inhibitors prevented the nuclear changes, identifying novel neuroprotection targets.
Collapse
Affiliation(s)
- Anisa Dehghani
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, 06100, Turkey
| | - Hulya Karatas
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, 06100, Turkey
| | - Alp Can
- Ankara University, School of Medicine, Department of Histology and Embryology, Ankara, 06100, Turkey
| | - Esra Erdemli
- Ankara University, School of Medicine, Department of Histology and Embryology, Ankara, 06100, Turkey
| | - Muge Yemisci
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, 06100, Turkey.,Hacettepe University, Faculty of Medicine, Department of Neurology, Ankara, 06100, Turkey
| | - Emine Eren-Kocak
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, 06100, Turkey.,Hacettepe University, Faculty of Medicine, Department of Psychiatry, Ankara, 06100, Turkey
| | - Turgay Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, 06100, Turkey. .,Hacettepe University, Faculty of Medicine, Department of Neurology, Ankara, 06100, Turkey.
| |
Collapse
|
23
|
Dönmez-Demir B, Yemisci M, Dalkara T. Data of ascending cortical vein occlusion induced spreading depression. Data Brief 2018; 18:1462-1465. [PMID: 29900326 PMCID: PMC5997957 DOI: 10.1016/j.dib.2018.04.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 01/22/2018] [Accepted: 04/12/2018] [Indexed: 11/01/2022] Open
Abstract
The data presented in this article are related to the research article entitled "Microembolism of single cortical arterioles can induce spreading depression and ischemic injury; a potential trigger for migraine and related MRI lesions" (Donmez-Demir et al., 2018) [1]. This article presents data showing that thrombosis of a small ascending cortical vein (25 µm) in the mouse may also trigger spreading depression as does penetrating arteriole occlusion, although less frequently (22% vs. 100%).
Collapse
Affiliation(s)
- Buket Dönmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| |
Collapse
|
24
|
Yapıcı-Eser H, Dönmez-Demir B, Kılıç K, Eren-Koçak E, Dalkara T. Stress modulates cortical excitability via α-2 adrenergic and glucocorticoid receptors: As assessed by spreading depression. Exp Neurol 2018; 307:45-51. [PMID: 29856967 DOI: 10.1016/j.expneurol.2018.05.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [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: 04/05/2018] [Revised: 05/15/2018] [Accepted: 05/27/2018] [Indexed: 12/29/2022]
Abstract
An increase in cortical excitability may be one of the factors mediating stress-induced vulnerability to neuropsychiatric disorders. Since stress increases extracellular glutamate and predisposes to migraine with aura attacks, we aimed to study the effect of stress on cortical spreading depression (CSD), the biological substrate of migraine aura and a measure of cortical excitability. CSD was induced by increasing concentrations of KCl applied over the dura with 5-minute intervals and recorded from parieto-occipital cortex to assess the CSD-induction threshold in acutely-stressed, chronically-stressed and naive mice. To study the mechanisms of acute stress-induced decrease in CSD threshold, we systemically administered clonidine, yohimbine, propranolol, CRH1 receptor antagonist NBI27914, mifepristone and spironolactone at doses shown to be effective on stress as well as a central noradrenergic neurotoxin (DSP-4) before acute stress. CSD threshold was significantly lowered by acute and chronic stress as well as central noradrenergic denervation. Clonidine and mifepristone further decreased the CSD threshold below the acute stress-induced levels, whereas yohimbine reversed the acute stress-induced decrease in CSD threshold compared to the saline-injected and stressed control groups. Propranolol, NBI27914 and spironolactone did not modify the effect of acute stress on CSD threshold. Stress increases cortical excitability as illustrated by a decrease in CSD-induction threshold. This action of acute stress is mediated by α2-adrenergic and glucocorticoid receptors. The decrease in CSD threshold may account for the stress-induced susceptibility to migraine. CSD may be used as a tool to study the link between stress-related disorders and cortical excitability.
Collapse
Affiliation(s)
- Hale Yapıcı-Eser
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; School of Medicine, Department of Psychiatry, Koç University & Research Center for Translational Medicine (KUTTAM), Koç University, İstanbul, Turkey
| | - Buket Dönmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Kıvılcım Kılıç
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; Neurophotonics Center, Boston University, Boston, MA, United States
| | - Emine Eren-Koçak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
25
|
Arsava EM, Hansen MB, Kaplan B, Peker A, Gocmen R, Arat A, Oguz KK, Topcuoglu MA, Østergaard L, Dalkara T. The effect of carotid artery stenting on capillary transit time heterogeneity in patients with carotid artery stenosis. Eur Stroke J 2018; 3:263-271. [PMID: 31008357 DOI: 10.1177/2396987318772686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 11/30/2017] [Accepted: 04/01/2018] [Indexed: 11/17/2022] Open
Abstract
Introduction Carotid revascularisation improves haemodynamic compromise in cerebral circulation as an additional benefit to the primary goal of reducing future thromboembolic risk. We determined the effect of carotid artery stenting on cerebral perfusion and oxygenation using a perfusion-weighted MRI algorithm that is based on assessment of capillary transit-time heterogeneity together with other perfusion and metabolism-related metrics. Patients and methods A consecutive series of 33 patients were evaluated by dynamic susceptibility contrast perfusion-weighted MRI prior to and within 24 h of the endovascular procedure. The level of relative change induced by stenting, and relationship of these changes with respect to baseline stenosis degree were analysed. Results Stenting led to significant increase in cerebral blood flow (p < 0.001), and decrease in cerebral blood volume (p = 0.001) and mean transit time (p < 0.001); this was accompanied by reduction in oxygen extraction fraction (p < 0.001) and capillary transit-time heterogeneity (p < 0.001), but an overall increase in relative capillary transit-time heterogeneity (RTH: CTH divided by MTT; p = 0.008). No significant change was observed with respect to cerebral metabolic rate of oxygen. The median volume of tissue with MTT > 2s decreased from 24 ml to 12 ml (p = 0.009), with CTH > 2s from 29 ml to 19 ml (p = 0.041), and with RTH < 0.9 from 61 ml to 39 ml (p = 0.037) following stenting. These changes were correlated with the baseline degree of stenosis.Discussion: Stenting improved the moderate stage of haemodynamic compromise at baseline in our cohort. The decreased relative transit-time heterogeneity, which increases following stenting, is probably a reflection of decreased functional capillary density secondary to chronic hypoperfusion induced by the proximal stenosis.Conclusion: Carotid artery stenting, is not only important for prophylaxis of future vascular events, but also is critical for restoration of microvascular function in the cerebral tissue.
Collapse
Affiliation(s)
- Ethem M Arsava
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey
| | - Mikkel B Hansen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience, Aarhus University, Denmark
| | - Berkan Kaplan
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey
| | - Ahmet Peker
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Rahsan Gocmen
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Anil Arat
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Kader K Oguz
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Mehmet A Topcuoglu
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey
| | - Leif Østergaard
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience, Aarhus University, Denmark.,Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Turgay Dalkara
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey.,Institute of Neurological Sciences and Psychiatry, Hacettepe University, Turkey
| |
Collapse
|
26
|
Taskiran-Sag A, Yemisci M, Gursoy-Ozdemir Y, Erdener SE, Karatas H, Yuce D, Dalkara T. Improving Microcirculatory Reperfusion Reduces Parenchymal Oxygen Radical Formation and Provides Neuroprotection. Stroke 2018; 49:1267-1275. [PMID: 29669868 DOI: 10.1161/strokeaha.118.020711] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [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: 09/05/2017] [Revised: 03/17/2018] [Accepted: 03/20/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE Reperfusion is the most significant determinant of good outcome after ischemic stroke. However, complete reperfusion often cannot be achieved, despite satisfactory recanalization. We hypothesized that microvascular protection was essential for achieving effective reperfusion and, hence, neuroprotection. To test this hypothesis, we have developed an in vivo model to differentially monitor parenchymal and vascular reactive oxygen species (ROS) formation. By comparing the ROS-suppressing effect of N-tert-butyl-α-phenylnitrone (PBN) with its blood-brain barrier impermeable analog 2-sulfo-phenyl-N-tert-butylnitrone (S-PBN), we assessed the impact of vascular ROS suppression alone on reperfusion and stroke outcome after recanalization. METHODS The distal middle cerebral artery was occluded for 1 hour by compressing with a micropipette and then recanalized (n=60 Swiss mice). ROS formation was monitored for 1 hour after recanalization by intravital fluorescence microscopy in pial vasculature and cortical parenchyma with topically applied hydroethidine through a cranial window. PBN (100 mg/kg) or S-PBN (156 mg/kg) was administered shortly before recanalization, and suppression of the vascular and parenchymal hydroethidine fluorescence was examined (n=22). Microcirculatory patency, reperfusion, ischemic tissue size, and neurological outcome were also assessed in a separate group of mice 1 to 72 hours after recanalization (n=30). RESULTS PBN and S-PBN completely suppressed the reperfusion-induced increase in ROS signal within vasculature. PBN readily suppressed ROS produced in parenchyma by 88%. S-PBN also suppressed the parenchymal ROS by 64% but starting 40 minutes later. Intriguingly, PBN and S-PBN comparably reduced the size of ischemic area by 65% and 48% (P>0.05), respectively. S-PBN restored the microvascular patency and perfusion after recanalization, suggesting that its delayed parenchymal antioxidant effect could be secondary to improved microcirculatory reperfusion. CONCLUSIONS Promoting microvascular reperfusion by protecting vasculature can secondarily reduce parenchymal ROS formation and provide neuroprotection. The model presented can be used to directly assess pharmacological end points postulated in brain parenchyma and vasculature in vivo.
Collapse
Affiliation(s)
- Aslihan Taskiran-Sag
- From the Institute of Neurological Sciences and Psychiatry (A.T.-S., M.Y., Y.G.-O., S.E.E., H.K., T.D.)
| | - Muge Yemisci
- From the Institute of Neurological Sciences and Psychiatry (A.T.-S., M.Y., Y.G.-O., S.E.E., H.K., T.D.).,Department of Neurology (M.Y., Y.G.-O., T.D.)
| | - Yasemin Gursoy-Ozdemir
- From the Institute of Neurological Sciences and Psychiatry (A.T.-S., M.Y., Y.G.-O., S.E.E., H.K., T.D.).,Department of Neurology (M.Y., Y.G.-O., T.D.)
| | - Sefik Evren Erdener
- From the Institute of Neurological Sciences and Psychiatry (A.T.-S., M.Y., Y.G.-O., S.E.E., H.K., T.D.)
| | - Hulya Karatas
- From the Institute of Neurological Sciences and Psychiatry (A.T.-S., M.Y., Y.G.-O., S.E.E., H.K., T.D.)
| | - Deniz Yuce
- Institute of Cancer (D.Y.), Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- From the Institute of Neurological Sciences and Psychiatry (A.T.-S., M.Y., Y.G.-O., S.E.E., H.K., T.D.) .,Department of Neurology (M.Y., Y.G.-O., T.D.)
| |
Collapse
|
27
|
Alarcon-Martinez L, Yilmaz-Ozcan S, Yemisci M, Schallek J, Kılıç K, Can A, Di Polo A, Dalkara T. Capillary pericytes express α-smooth muscle actin, which requires prevention of filamentous-actin depolymerization for detection. eLife 2018; 7:e34861. [PMID: 29561727 PMCID: PMC5862523 DOI: 10.7554/elife.34861] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [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: 01/08/2018] [Accepted: 02/12/2018] [Indexed: 01/12/2023] Open
Abstract
Recent evidence suggests that capillary pericytes are contractile and play a crucial role in the regulation of microcirculation. However, failure to detect components of the contractile apparatus in capillary pericytes, most notably α-smooth muscle actin (α-SMA), has questioned these findings. Using strategies that allow rapid filamentous-actin (F-actin) fixation (i.e. snap freeze fixation with methanol at -20°C) or prevent F-actin depolymerization (i.e. with F-actin stabilizing agents), we demonstrate that pericytes on mouse retinal capillaries, including those in intermediate and deeper plexus, express α-SMA. Junctional pericytes were more frequently α-SMA-positive relative to pericytes on linear capillary segments. Intravitreal administration of short interfering RNA (α-SMA-siRNA) suppressed α-SMA expression preferentially in high order branch capillary pericytes, confirming the existence of a smaller pool of α-SMA in distal capillary pericytes that is quickly lost by depolymerization. We conclude that capillary pericytes do express α-SMA, which rapidly depolymerizes during tissue fixation thus evading detection by immunolabeling.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
- Centre de Recherche du Centre Hospitalier de l’Université de MontréalUniversité de Montréal, MontréalQuébecCanada
- Department of NeuroscienceUniversité de Montréal, MontréalQuébecCanada
| | - Sinem Yilmaz-Ozcan
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
| | - Muge Yemisci
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
- Department of NeurologyFaculty of Medicine, Hacettepe UniversityAnkaraTurkey
| | - Jesse Schallek
- Center for Visual ScienceUniversity of RochesterNew YorkUnited States
- Flaum Eye InstituteUniversity of RochesterNew YorkUnited States
| | - Kıvılcım Kılıç
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
| | - Alp Can
- Department of Histology and EmbryologySchool of Medicine, Ankara UniversityAnkaraTurkey
| | - Adriana Di Polo
- Centre de Recherche du Centre Hospitalier de l’Université de MontréalUniversité de Montréal, MontréalQuébecCanada
- Department of NeuroscienceUniversité de Montréal, MontréalQuébecCanada
| | - Turgay Dalkara
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
- Department of NeurologyFaculty of Medicine, Hacettepe UniversityAnkaraTurkey
| |
Collapse
|
28
|
Yemisci M, Caban S, Fernandez-Megia E, Capan Y, Couvreur P, Dalkara T. Preparation and Characterization of Biocompatible Chitosan Nanoparticles for Targeted Brain Delivery of Peptides. Methods Mol Biol 2018; 1727:443-454. [PMID: 29222804 DOI: 10.1007/978-1-4939-7571-6_36] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Here, we describe a nanocarrier system that can transfer chitosan nanoparticles loaded with either small peptides such as the caspase inhibitor Z-DEVD-FMK or a large peptide like basic fibroblast growth factor across the blood-brain barrier. The nanoparticles are selectively directed to the brain and are not measurably taken up by the liver and spleen. Intravital fluorescent microscopy provides an opportunity to study the penetration kinetics of nanoparticles loaded with fluorescent agents such as Nile red. Nanoparticles functionalized with anti-transferrin antibody and loaded with peptides efficiently provided neuroprotection when systemically administered either as a formulation bearing a single peptide or a mixture of them. Failure of brain permeation of the nanoparticles after inhibition of vesicular transcytosis by imatinib as well as when nanoparticles were not functionalized with anti-transferrin antibody indicates that this nanomedicine formulation is rapidly transported across the blood-brain barrier by receptor-mediated transcytosis.
Collapse
Affiliation(s)
- Muge Yemisci
- Faculty of Medicine, Department of Neurology, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Secil Caban
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Hacettepe University, Ankara, Turkey
| | - Eduardo Fernandez-Megia
- Departamento de Química Orgánica, Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Yilmaz Capan
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Hacettepe University, Ankara, Turkey
| | - Patrick Couvreur
- Faculté de Pharmacie, Institut Galien Paris-Sud, UMR 8612, CNRS, Univ Paris-Sud, Université Paris-Saclay, Châtenay-Malabry Cedex, France
| | - Turgay Dalkara
- Faculty of Medicine, Department of Neurology, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| |
Collapse
|
29
|
Dönmez-Demir B, Yemisci M, Kılıç K, Gürsoy-Özdemir Y, Söylemezoğlu F, Moskowitz M, Dalkara T. Microembolism of single cortical arterioles can induce spreading depression and ischemic injury; a potential trigger for migraine and related MRI lesions. Brain Res 2017; 1679:84-90. [PMID: 29183666 DOI: 10.1016/j.brainres.2017.11.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 12/13/2022]
Abstract
Increasing epidemiological evidence suggests an association between migraine with aura (MA) and cardiovascular events. There is experimental as well as clinical evidence implying cerebral microembolism as a potential trigger for MA attacks. Microembolism may also account for some of the ischemic MRI lesions more commonly observed in MA than in general population. Limited size of clinically-silent MRI lesions suggests isolated occlusion of a small vessel. However, it is not known whether selective thrombosis of a small arteriole (e.g. single mouse penetrating arteriole - PA), can induce cortical spreading depression (CSD), the putative cause of migraine aura and, hence, trigger an MA attack. For this, we mimiced thrombosis of a small vessel caused by microembolism by selectively occluding a PA just before diving into the cortex (radius; 10-25 µm) in the mouse. Clotting was induced with FeCl3 applied focally over the PA by a glass micropipette for 3 min. DC potential changes were recorded and the alterations in cortical blood flow were monitored by laser speckle contrast imaging. Mice were kept alive for 1-4 weeks and brain sections were stained with H&E or luxol-fast blue to evaluate changes induced by PA occlusion. We found that single PA occlusion consistently triggered a CSD originating from the tissue around the PA soon after occlusion and induced delayed, small ischemic lesions within territory of the affected vessel a few weeks later. These findings suggest that cerebral microembolism can lead to MA attacks and may account for some of the silent brain lesions.
Collapse
Affiliation(s)
- Buket Dönmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Kıvılcım Kılıç
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Yasemin Gürsoy-Özdemir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey; Department of Neurology, School of Medicine, Koç University, İstanbul, Turkey
| | - Figen Söylemezoğlu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Michael Moskowitz
- Neuroscience Center, Massachusetts General Hospital, Harvard University, Boston, USA
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey; Neuroscience Center, Massachusetts General Hospital, Harvard University, Boston, USA.
| |
Collapse
|
30
|
Lule S, Colpak A, Balci-Peynircioglu B, Gursoy-Ozdemir Y, Peker S, Kalyoncu U, Can A, Tekin N, Demiralp D, Dalkara T. Behçet Disease serum is immunoreactive to neurofilament medium which share common epitopes to bacterial HSP-65, a putative trigger. J Autoimmun 2017; 84:87-96. [DOI: 10.1016/j.jaut.2017.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/28/2017] [Accepted: 08/01/2017] [Indexed: 01/01/2023]
|
31
|
Colpak AI, Balci-Peynircioglu B, Can A, Gursoy-Ozdemir Y, Lule S, Kalyoncu U, Dalkara T. Data of indirect immunofluorescence labeling of the mouse brain sections with sera from SLE and MS patients. Data Brief 2017; 15:170-173. [PMID: 29034286 PMCID: PMC5633813 DOI: 10.1016/j.dib.2017.09.027] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/07/2017] [Accepted: 09/13/2017] [Indexed: 11/28/2022] Open
Abstract
The data presented in this article are related to the research article entitled "Behcet Disease serum is immunoreactive to neurofilament medium which share common epitopes to bacterial HSP-65, a putative trigger" (Lule et a. 2017) [1]. The immunoreactivity to self-antigens is well characterized for systemic lupus erythematosus (SLE) and multiple sclerosis (MS) (Magro Checa et al., 2013) [2]. Indirect immunofluorescence labeling of the mouse tissue sections with patient sera has recently been popular to discover novel epitopes and gain mechanistic insight to diseases with dysregulated immunity (Lennon et al., 2004) [3]. The present article demonstrates widespread labeling of cell nuclei with SLE patient sera and sporadic filamentous labeling along the axons with MS patient sera on mouse brain sections. The filamentous immunolabeling was sometimes associated with cytoplasmic staining of cells, which sent processes along the axon bundles, suggesting that they were oligodendrocytes. Since the mouse brain tissue has little autofluorescence and limited connective tissue causing non-specific immunolabeling, it appears superior to peripheral tissues for searching serum immunoreactivity.
Collapse
Affiliation(s)
- Ayse Ilksen Colpak
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Banu Balci-Peynircioglu
- Institute of Neurological Sciences and Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Current affiliation: Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Alp Can
- Department of Histology and Embryology, School of Medicine, Ankara University, Ankara, Turkey
| | - Yasemin Gursoy-Ozdemir
- Institute of Neurological Sciences and Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Current affiliation: Department of Neurology, School of Medicine (KUSOM), Koç University, İstanbul, Turkey
| | - Sevda Lule
- Institute of Neurological Sciences and Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Umut Kalyoncu
- Department of Internal Medicine, Division of Rheumatology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Institute of Neurological Sciences and Psychiatry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| |
Collapse
|
32
|
Yilmaz-Ozcan S, Alarcon-Martinez L, Donmez-Demir B, Dalkara T, Yemisci M. In vivo alpha-smooth muscle actin down regulation by small interfering RNA reduces pericyte contraction in the brain and retina of mice. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.3177] [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: 10/18/2022]
|
33
|
Seyrantepe V, Demir SA, Timur ZK, Von Gerichten J, Marsching C, Erdemli E, Oztas E, Takahashi K, Yamaguchi K, Ates N, Dönmez Demir B, Dalkara T, Erich K, Hopf C, Sandhoff R, Miyagi T. Murine Sialidase Neu3 facilitates GM2 degradation and bypass in mouse model of Tay-Sachs disease. Exp Neurol 2017; 299:26-41. [PMID: 28974375 DOI: 10.1016/j.expneurol.2017.09.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [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: 07/13/2017] [Revised: 09/14/2017] [Accepted: 09/28/2017] [Indexed: 12/29/2022]
Abstract
Tay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal β-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa-/- mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by β-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa-/-Neu3-/- mice were healthy at birth, but died at 1.5 to 4.5months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa-/-Neu3-/- mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa-/-Neu3-/- mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa-/-Neu3-/- mice. Thus, the Hexa-/-Neu3-/- mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition.
Collapse
Affiliation(s)
- Volkan Seyrantepe
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey.
| | - Secil Akyildiz Demir
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Zehra Kevser Timur
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Johanna Von Gerichten
- Lipid Pathobiochemistry Group (G131) German Cancer Research Center, INF 280, 69120 Heidelberg, Germany
| | - Christian Marsching
- Lipid Pathobiochemistry Group (G131) German Cancer Research Center, INF 280, 69120 Heidelberg, Germany; Center for Applied Research in Applied Biomedical Mass Spectrometry (ABIMAS), Mannheim, Germany; Institute of Medical Technology (IMT) of Heidelberg University and Mannheim University of Applied Sciences, Paul-Wittsach-Str.10, 68163 Mannheim, Germany
| | - Esra Erdemli
- Departments of Histology and Embryology, Ankara University, Medical School, 06100, Sihhiye, Ankara, Turkey
| | - Emin Oztas
- Departments of Histology and Embryology, GATA Medical School, 06100 Ankara, Turkey
| | - Kohta Takahashi
- Cell Recognition Study, Tohoku Pharmaceutical University, Sendai, Japan
| | | | - Nurselin Ates
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Buket Dönmez Demir
- Institutes of Neurological Science and Psychiatry, University of Hacettepe, 06100 Ankara, Turkey
| | - Turgay Dalkara
- Institutes of Neurological Science and Psychiatry, University of Hacettepe, 06100 Ankara, Turkey
| | - Katrin Erich
- Center for Applied Research in Applied Biomedical Mass Spectrometry (ABIMAS), Mannheim, Germany; Institute of Medical Technology (IMT) of Heidelberg University and Mannheim University of Applied Sciences, Paul-Wittsach-Str.10, 68163 Mannheim, Germany
| | - Carsten Hopf
- Center for Applied Research in Applied Biomedical Mass Spectrometry (ABIMAS), Mannheim, Germany; Institute of Medical Technology (IMT) of Heidelberg University and Mannheim University of Applied Sciences, Paul-Wittsach-Str.10, 68163 Mannheim, Germany
| | - Roger Sandhoff
- Lipid Pathobiochemistry Group (G131) German Cancer Research Center, INF 280, 69120 Heidelberg, Germany
| | - Taeko Miyagi
- Miyagi Cancer Center Research Institute, Natori, Japan
| |
Collapse
|
34
|
Arsava EM, Arat A, Topcuoglu MA, Peker A, Yemisci M, Dalkara T. Angiographic Microcirculatory Obstructions Distal to Occlusion Signify Poor Outcome after Endovascular Treatment for Acute Ischemic Stroke. Transl Stroke Res 2017; 9:44-50. [DOI: 10.1007/s12975-017-0562-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/18/2017] [Accepted: 08/08/2017] [Indexed: 11/29/2022]
|
35
|
Abstract
Although progress has been made for recanalization therapies after ischemic stroke, post-treatment imaging studies show that tissue reperfusion cannot be attained despite satisfactory recanalization in a significant percentage of patients. Hence, investigation of microcirculatory changes in both surface and deep cortical levels after ischemia reperfusion is important for understanding the post-stroke blood flow dynamics. In this study, we applied optical coherence tomography (OCT) imaging of cerebral blood flow for the quantification of the microcirculatory changes. We obtained OCT microangiogram of the brain cortex in a mouse stroke model and analyzed the data to trace changes in the capillary perfusion level (CPL) before, during, and after the stroke. The CPL changes were estimated in 1 and 2 h ischemia groups as well as in a non-ischemic sham-operated group. For the estimation of CPL, a decorrelation amplitude-based algorithm was implemented and used. As a result, the CPL considerably decreased during ischemia but recovered to the baseline when recanalization was performed 1 h after ischemia; however, the CPL was significantly reduced when recanalization was delayed to 2 h after ischemia. These data demonstrate that ischemia causes microcirculation dysfunction, leading to a decreased capillary reperfusion after recanalization. Microcirculatory no-reflow warrants more rigorous assessment in clinical trials, whereas advanced optical imaging techniques may provide mechanistic insight and solutions in experimental studies.
Collapse
Affiliation(s)
- Jonghwan Lee
- School of Engineering, Institute for Brain Science, Brown University, Providence, Rhode Island 02912, USA
- Corresponding author:
| | - Yasemin Gursoy-Ozdemir
- Currently at Koc University School of Medicine, Department of Neurology, Istanbul, Turkey
- Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Buyin Fu
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - David A. Boas
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| |
Collapse
|
36
|
Kutluk K, Kaya D, Afsar N, Arsava EM, Ozturk V, Uzuner N, Giray S, Topcuoglu MA, Gungor L, Sirin H, Yaka E, Ozdemir O, Dalkara T. Analyses of the Turkish National Intravenous Thrombolysis Registry. J Stroke Cerebrovasc Dis 2016; 25:1041-1047. [PMID: 26853139 DOI: 10.1016/j.jstrokecerebrovasdis.2016.01.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/30/2015] [Accepted: 01/05/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The relatively late approval of use of recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke in Turkey has resulted in obvious underuse of this treatment. Here we present the analyses of the nationwide registry, which was created to prompt wider use of intravenous thrombolysis, as well as to monitor safe implementation of the treatment in our country. METHODS Patients were registered prospectively in our database between 2006 and 2013. Admission and 24-hour National Institutes of Health Stroke Scale and 3-month modified Rankin Scale scores were recorded. A "high-volume center" was defined as a center treating 10 or more patients with rt-PA per year. RESULTS A total of 1133 patients were enrolled into the registry by 38 centers in 18 cities. A nearly 4-fold increase in the study population and in the number of participating centers was observed over the 6 years of the study. The mean baseline NIHSS score was 14.5 ± 5.7, and the prevalence of symptomatic hemorrhage was 4.9%. Mortality at 3 months decreased from 22% to 11% in the 6 years of enrollment, and 65% of cases were functionally independent. Age older than 70 years, an NIHSS score higher than 14 upon hospital admission, and intracranial hemorrhage were independently associated with mortality, and being treated in a high-volume center was related to good outcome. CONCLUSIONS We observed a decreasing trend in mortality and an acceptable prevalence of symptomatic hemorrhage over 6 years with continuous addition of new centers to the registry. The first results of this prospective study are encouraging and will stimulate our efforts at increasing the use of intravenous thrombolysis in Turkey.
Collapse
Affiliation(s)
- Kursad Kutluk
- Department of Neurology, University of Dokuz Eylul, Izmir, Turkey.
| | - Dilaver Kaya
- Department of Neurology, University of Acibadem, Istanbul, Turkey
| | - Nazire Afsar
- Department of Neurology, University of Bahcesehir, Istanbul, Turkey
| | | | - Vesile Ozturk
- Department of Neurology, University of Dokuz Eylul, Izmir, Turkey
| | - Nevzat Uzuner
- Department of Neurology, University of Osman Gazi, Eskisehir, Turkey
| | - Semih Giray
- Department of Neurology, University of Gaziantep, Gaziantep, Turkey
| | | | - Levent Gungor
- Department of Neurology, University of Ondokuz Mayis, Samsun, Turkey
| | - Hadiye Sirin
- Department of Neurology, University of Ege, Izmir, Turkey
| | - Erdem Yaka
- Department of Neurology, University of Dokuz Eylul, Izmir, Turkey
| | - Ozcan Ozdemir
- Department of Neurology, University of Osman Gazi, Eskisehir, Turkey
| | - Turgay Dalkara
- Department of Neurology, University of Hacettepe, Ankara, Turkey
| |
Collapse
|
37
|
Østergaard L, Engedal TS, Moreton F, Hansen MB, Wardlaw JM, Dalkara T, Markus HS, Muir KW. Cerebral small vessel disease: Capillary pathways to stroke and cognitive decline. J Cereb Blood Flow Metab 2016; 36:302-25. [PMID: 26661176 PMCID: PMC4759673 DOI: 10.1177/0271678x15606723] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 07/30/2015] [Indexed: 01/18/2023]
Abstract
Cerebral small vessel disease (SVD) gives rise to one in five strokes worldwide and constitutes a major source of cognitive decline in the elderly. SVD is known to occur in relation to hypertension, diabetes, smoking, radiation therapy and in a range of inherited and genetic disorders, autoimmune disorders, connective tissue disorders, and infections. Until recently, changes in capillary patency and blood viscosity have received little attention in the aetiopathogenesis of SVD and the high risk of subsequent stroke and cognitive decline. Capillary flow patterns were, however, recently shown to limit the extraction efficacy of oxygen in tissue and capillary dysfunction therefore proposed as a source of stroke-like symptoms and neurodegeneration, even in the absence of physical flow-limiting vascular pathology. In this review, we examine whether capillary flow disturbances may be a shared feature of conditions that represent risk factors for SVD. We then discuss aspects of capillary dysfunction that could be prevented or alleviated and therefore might be of general benefit to patients at risk of SVD, stroke or cognitive decline.
Collapse
Affiliation(s)
- Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark
| | - Thorbjørn S Engedal
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Fiona Moreton
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
| | - Mikkel B Hansen
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Hugh S Markus
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Keith W Muir
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
| |
Collapse
|
38
|
Abstract
Pericytes, spatially isolated contractile cells on capillaries, have been reported to control cerebral blood flow physiologically, and to limit blood flow after ischaemia by constricting capillaries and then dying. Paradoxically, a recent paper dismisses the idea of pericytes controlling cerebral blood flow, despite confirming earlier data showing a role for pericytes. We show that these discrepancies are apparent rather than real, and depend on the new paper defining pericytes differently from previous reports. An objective definition of different sub-classes of pericyte along the capillary bed is needed to develop novel therapeutic approaches for stroke and disorders caused by pericyte malfunction.
Collapse
Affiliation(s)
- David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Anusha Mishra
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Catherine N Hall
- School of Psychology, University of Sussex, Falmer, Brighton, UK
| | - Fergus M O'Farrell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, and Department of Neurology, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara, Turkey
| |
Collapse
|
39
|
Dalkara T, Alarcon-Martinez L. Cerebral microvascular pericytes and neurogliovascular signaling in health and disease. Brain Res 2015; 1623:3-17. [DOI: 10.1016/j.brainres.2015.03.047] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/10/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023]
|
40
|
Østergaard L, Dreier JP, Hadjikhani N, Jespersen SN, Dirnagl U, Dalkara T. Neurovascular coupling during cortical spreading depolarization and -depression. Stroke 2015; 46:1392-401. [PMID: 25882051 DOI: 10.1161/strokeaha.114.008077] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/17/2015] [Indexed: 01/03/2023]
Affiliation(s)
- Leif Østergaard
- From the Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Denmark (L.Ø., S.N.J.); Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark (L.Ø.); Center for Stroke Research and Departments of Experimental Neurology and Neurology, Charité Universitätsmedizin, Berlin, Germany (J.P.D., U.D.); Pathophysiology and Cognition Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School (N.H.); Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark (S.N.J.); and Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (T.D.).
| | - Jens Peter Dreier
- From the Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Denmark (L.Ø., S.N.J.); Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark (L.Ø.); Center for Stroke Research and Departments of Experimental Neurology and Neurology, Charité Universitätsmedizin, Berlin, Germany (J.P.D., U.D.); Pathophysiology and Cognition Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School (N.H.); Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark (S.N.J.); and Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (T.D.)
| | - Nouchine Hadjikhani
- From the Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Denmark (L.Ø., S.N.J.); Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark (L.Ø.); Center for Stroke Research and Departments of Experimental Neurology and Neurology, Charité Universitätsmedizin, Berlin, Germany (J.P.D., U.D.); Pathophysiology and Cognition Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School (N.H.); Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark (S.N.J.); and Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (T.D.)
| | - Sune Nørhøj Jespersen
- From the Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Denmark (L.Ø., S.N.J.); Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark (L.Ø.); Center for Stroke Research and Departments of Experimental Neurology and Neurology, Charité Universitätsmedizin, Berlin, Germany (J.P.D., U.D.); Pathophysiology and Cognition Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School (N.H.); Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark (S.N.J.); and Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (T.D.)
| | - Ulrich Dirnagl
- From the Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Denmark (L.Ø., S.N.J.); Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark (L.Ø.); Center for Stroke Research and Departments of Experimental Neurology and Neurology, Charité Universitätsmedizin, Berlin, Germany (J.P.D., U.D.); Pathophysiology and Cognition Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School (N.H.); Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark (S.N.J.); and Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (T.D.)
| | - Turgay Dalkara
- From the Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Denmark (L.Ø., S.N.J.); Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark (L.Ø.); Center for Stroke Research and Departments of Experimental Neurology and Neurology, Charité Universitätsmedizin, Berlin, Germany (J.P.D., U.D.); Pathophysiology and Cognition Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School (N.H.); Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark (S.N.J.); and Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey (T.D.)
| |
Collapse
|
41
|
Yemisci M, Caban S, Gursoy-Ozdemir Y, Lule S, Novoa-Carballal R, Riguera R, Fernandez-Megia E, Andrieux K, Couvreur P, Capan Y, Dalkara T. Systemically administered brain-targeted nanoparticles transport peptides across the blood-brain barrier and provide neuroprotection. J Cereb Blood Flow Metab 2015; 35:469-75. [PMID: 25492116 PMCID: PMC4348388 DOI: 10.1038/jcbfm.2014.220] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/07/2014] [Accepted: 11/11/2014] [Indexed: 11/09/2022]
Abstract
Although growth factors and anti-apoptotic peptides have been shown to be neuroprotective in stroke models, translation of these experimental findings to clinic is hampered by limited penetration of peptides to the brain. Here, we show that a large peptide like the basic fibroblast growth factor (bFGF) and a small peptide inhibitor of caspase-3 (z-DEVD-FMK) can effectively be transported to the brain after systemic administration by incorporating these peptides to brain-targeted nanoparticles (NPs). Chitosan NPs were loaded with peptides and then functionalized by conjugating with antibodies directed against the transferrin receptor-1 on brain endothelia to induce receptor-mediated transcytosis across the blood-brain barrier (BBB). Pre-ischemic systemic administration of bFGF- or z-DEVD-FMK-loaded NPs significantly decreased the infarct volume after 2-hour middle cerebral artery occlusion and 22-hour reperfusion in mice. Co-administration of bFGF- or z-DEVD-FMK-loaded NPs reduced the infarct volume further and provided a 3-hour therapeutic window. bFGF-loaded NPs were histologically detected in the brain parenchyma and also restored ischemia-induced Akt dephosphorylation. The neuroprotection was not observed when receptor-mediated transcytosis was inhibited with imatinib or when bFGF-loaded NPs were not conjugated with the targeting antibody, which enables them to cross the BBB. Nanoparticles targeted to brain are promising drug carriers to transport large as well as small BBB-impermeable therapeutics for neuroprotection against stroke.
Collapse
Affiliation(s)
- Muge Yemisci
- Department of Neurology, Faculty of Medicine, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Secil Caban
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Yasemin Gursoy-Ozdemir
- Department of Neurology, Faculty of Medicine, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Sevda Lule
- Department of Neurology, Faculty of Medicine, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Ramon Novoa-Carballal
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Ricardo Riguera
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Eduardo Fernandez-Megia
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Karine Andrieux
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, Chátenay-Malabry, France
| | - Partick Couvreur
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, Chátenay-Malabry, France
| | - Yilmaz Capan
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Department of Neurology, Faculty of Medicine, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
42
|
Gaudin A, Yemisci M, Eroglu H, Lepetre-Mouelhi S, Turkoglu OF, Dönmez-Demir B, Caban S, Sargon MF, Garcia-Argote S, Pieters G, Loreau O, Rousseau B, Tagit O, Hildebrandt N, Dantec YL, Mougin J, Valetti S, Chacun H, Nicolas V, Desmaële D, Andrieux K, Capan Y, Dalkara T, Couvreur P. Erratum: Squalenoyl adenosine nanoparticles provide neuroprotection after stroke and spinal cord injury. Nat Nanotechnol 2015; 10:99. [PMID: 25559969 DOI: 10.1038/nnano.2014.312] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
|
43
|
Yıldırım T, Eylen A, Lule S, Erdener SE, Vural A, Karatas H, Ozveren MF, Dalkara T, Gursoy-Ozdemir Y. Poloxamer-188 and citicoline provide neuronal membrane integrity and protect membrane stability in cortical spreading depression. Int J Neurosci 2014; 125:941-6. [PMID: 25340256 DOI: 10.3109/00207454.2014.979289] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Under pathological conditions such as brain trauma, subarachnoid hemorrhage and stroke, cortical spreading depression (CSD) or peri-infarct depolarizations contribute to brain damage in animal models of neurological disorders as well as in human neurological diseases. CSD causes transient megachannel opening on the neuronal membrane, which may compromise neuronal survival under pathological conditions. Poloxamer-188 (P-188) and citicoline are neuroprotectants with membrane sealing properties. The aim of this study is to investigate the effect of P-188 and citicoline on the neuronal megachannel opening induced by CSD in the mouse brain. We have monitored megachannel opening with propidium iodide, a membrane impermeable fluorescent dye and, demonstrate that P-188 and citicoline strikingly decreased CSD-induced neuronal PI influx in cortex and hippocampal dentate gyrus. Therefore, these agents may be providing neuroprotection by blocking megachannel opening, which may be related to their membrane sealing action and warrant further investigation for treatment of traumatic brain injury and ischemic stroke.
Collapse
Affiliation(s)
- Timur Yıldırım
- a Department of Neurosurgery, Ankara Atatürk Education and Research Hospital , Ankara , Turkey
| | - Alpaslan Eylen
- b Department of Neurosurgery, Konya Numune Hospital , Konya , Turkey
| | - Sevda Lule
- c Institute of Neurological Sciences and Psychiatry, Hacettepe University , Ankara , Turkey
| | - Sefik Evren Erdener
- c Institute of Neurological Sciences and Psychiatry, Hacettepe University , Ankara , Turkey.,d Department of Neurology, Faculty of Medicine, Hacettepe University , Ankara , Turkey
| | - Atay Vural
- c Institute of Neurological Sciences and Psychiatry, Hacettepe University , Ankara , Turkey.,d Department of Neurology, Faculty of Medicine, Hacettepe University , Ankara , Turkey
| | - Hulya Karatas
- c Institute of Neurological Sciences and Psychiatry, Hacettepe University , Ankara , Turkey.,d Department of Neurology, Faculty of Medicine, Hacettepe University , Ankara , Turkey
| | - Mehmet Faik Ozveren
- e Department of Neurosurgery, Faculty of Medicine, Ordu University , Ordu , Turkey
| | - Turgay Dalkara
- c Institute of Neurological Sciences and Psychiatry, Hacettepe University , Ankara , Turkey.,d Department of Neurology, Faculty of Medicine, Hacettepe University , Ankara , Turkey
| | - Yasemin Gursoy-Ozdemir
- c Institute of Neurological Sciences and Psychiatry, Hacettepe University , Ankara , Turkey.,d Department of Neurology, Faculty of Medicine, Hacettepe University , Ankara , Turkey
| |
Collapse
|
44
|
Erdener SE, Dalkara T. Modelling headache and migraine and its pharmacological manipulation. Br J Pharmacol 2014; 171:4575-94. [PMID: 24611635 DOI: 10.1111/bph.12651] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/13/2014] [Accepted: 02/14/2014] [Indexed: 12/22/2022] Open
Abstract
Similarities between laboratory animals and humans in anatomy and physiology of the cephalic nociceptive pathways have allowed scientists to create successful models that have significantly contributed to our understanding of headache. They have also been instrumental in the development of novel anti-migraine drugs different from classical pain killers. Nevertheless, modelling the mechanisms underlying primary headache disorders like migraine has been challenging due to limitations in testing the postulated hypotheses in humans. Recent developments in imaging techniques have begun to fill this translational gap. The unambiguous demonstration of cortical spreading depolarization (CSD) during migraine aura in patients has reawakened interest in studying CSD in animals as a noxious brain event that can activate the trigeminovascular system. CSD-based models, including transgenics and optogenetics, may more realistically simulate pain generation in migraine, which is thought to originate within the brain. The realization that behavioural correlates of headache and migrainous symptoms like photophobia can be assessed quantitatively in laboratory animals, has created an opportunity to directly study the headache in intact animals without the confounding effects of anaesthetics. Headache and migraine-like episodes induced by administration of glyceryltrinitrate and CGRP to humans and parallel behavioural and biological changes observed in rodents create interesting possibilities for translational research. Not unexpectedly, species differences and model-specific observations have also led to controversies as well as disappointments in clinical trials, which, in return, has helped us improve the models and advance our understanding of headache. Here, we review commonly used headache and migraine models with an emphasis on recent developments.
Collapse
Affiliation(s)
- S E Erdener
- Department of Neurology, Faculty of Medicine, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | | |
Collapse
|
45
|
Kozlu S, Caban S, Yerlikaya F, Fernandez-Megia E, Novoa-Carballal R, Riguera R, Yemisci M, Gursoy-Ozdemir Y, Dalkara T, Couvreur P, Capan Y. An aquaporin 4 antisense oligonucleotide loaded, brain targeted nanoparticulate system design. Pharmazie 2014; 69:340-345. [PMID: 24855824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Aquaporins (AQPs), members of the water-channel protein family, are highly expressed in brain tissue especially in astrocytic end-feet. They are important players for water hemostasis during development of cytotoxic as well as vasogenic edema. Increased expression of AQPs is important in pathophysiology of neurological diseases such as neuroinflammation and ischemia. Unfortunately, there are a few pharmacological inhibitors of AQP4 with several side effects limiting their translation as a drug for use in clinical conditions. Another therapeutic approach is using antisense oligonucleotides (ASOs) to block AQP4 activity. These are short, synthetic, modified nucleic acids that bind RNA to modulate its function. However, they cannot pass the blood brain barrier (BBB). To overcome this obstacle we designed a nanoparticulate system made up of chitosan nanoparticles surface modified with PEG and conjugated with monoclonal anti transferrin receptor-1 antibody via streptavidin-biotin binding. The nanocarrier system could be targeted to the transferrin receptor-1 at the brain endothelial capillaries through monoclonal antibodies. It is hypothesized that the nanoparticles could pass the BBB via receptor mediated transcytosis and reach brain parenchyma. Particle size, zeta potential, loading capacity and release profiles of nanoparticles were investigated. It was observed that all types of chitosau (CS) nanoparticles had positive zeta potential values and nanoparticle particle size distribution varied between 100 and 800 nm. The association efficiency of ASOs into the nanoparticles was between 80-97% and the release profiles of the nanoparticles exhibited an initial burst effect followed by a controlled release. The results showed that the designed chitosan based nanocarriers could be a promising carrier system to transport nucleic acid based drugs to brain parenchyma.
Collapse
|
46
|
Gaudin A, Yemisci M, Eroglu H, Lepêtre-Mouelhi S, Turkoglu OF, Dönmez-Demir B, Caban S, Fevzi Sargon M, Garcia-Argote S, Pieters G, Loreau O, Rousseau B, Tagit O, Hildebrandt N, Le Dantec Y, Mougin J, Valetti S, Chacun H, Nicolas V, Desmaële D, Andrieux K, Capan Y, Dalkara T, Couvreur P. Squalenoyl adenosine nanoparticles provide neuroprotection after stroke and spinal cord injury. Nat Nanotechnol 2014; 9:1054-1062. [PMID: 25420034 PMCID: PMC4351925 DOI: 10.1038/nnano.2014.274] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/21/2014] [Indexed: 05/19/2023]
Abstract
There is an urgent need to develop new therapeutic approaches for the treatment of severe neurological trauma, such as stroke and spinal cord injuries. However, many drugs with potential neuropharmacological activity, such as adenosine, are inefficient upon systemic administration because of their fast metabolization and rapid clearance from the bloodstream. Here, we show that conjugation of adenosine to the lipid squalene and the subsequent formation of nanoassemblies allows prolonged circulation of this nucleoside, providing neuroprotection in mouse stroke and rat spinal cord injury models. The animals receiving systemic administration of squalenoyl adenosine nanoassemblies showed a significant improvement of their neurologic deficit score in the case of cerebral ischaemia, and an early motor recovery of the hindlimbs in the case of spinal cord injury. Moreover, in vitro and in vivo studies demonstrated that the nanoassemblies were able to extend adenosine circulation and its interaction with the neurovascular unit. This Article shows, for the first time, that a hydrophilic and rapidly metabolized molecule such as adenosine may become pharmacologically efficient owing to a single conjugation with the lipid squalene.
Collapse
Affiliation(s)
- Alice Gaudin
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Müge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara 06100, Turkey
| | - Hakan Eroglu
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara 06100, Turkey
| | - Sinda Lepêtre-Mouelhi
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Omer Faruk Turkoglu
- Department of Neurosurgery, Ankara Ataturk Research & Education Hospital, 06800 Bilkent Ankara, Turkey
| | - Buket Dönmez-Demir
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara 06100, Turkey
| | - Seçil Caban
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara 06100, Turkey
| | - Mustafa Fevzi Sargon
- Department of Anatomy, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | | | - Grégory Pieters
- CEA Saclay, iBiTecS-S/SCBM, Labex LERMIT, 91191 Gif-sur-Yvette, France
| | - Olivier Loreau
- CEA Saclay, iBiTecS-S/SCBM, Labex LERMIT, 91191 Gif-sur-Yvette, France
| | - Bernard Rousseau
- CEA Saclay, iBiTecS-S/SCBM, Labex LERMIT, 91191 Gif-sur-Yvette, France
| | - Oya Tagit
- NanoBioPhotonics, Institut d’Electronique Fondamentale, University of Paris-Sud XI, 91405, Orsay Cedex, France
| | - Niko Hildebrandt
- NanoBioPhotonics, Institut d’Electronique Fondamentale, University of Paris-Sud XI, 91405, Orsay Cedex, France
| | - Yannick Le Dantec
- EA3544, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Julie Mougin
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Sabrina Valetti
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Hélène Chacun
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Valérie Nicolas
- Institut d’Innovation Thérapeutique, IFR141 ITFM, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Didier Desmaële
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
| | - Karine Andrieux
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
- Correspondence and requests for materials should be adressed to P.C. and K.A. ,
| | - Yilmaz Capan
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara 06100, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara 06100, Turkey
| | - Patrick Couvreur
- Institut Galien Paris-Sud UMR CNRS 8612, Faculty of Pharmacy, University of Paris-Sud XI, 92296 Châtenay-Malabry, France
- Correspondence and requests for materials should be adressed to P.C. and K.A. ,
| |
Collapse
|
47
|
|
48
|
Karatas H, Erdener SE, Gursoy-Ozdemir Y, Lule S, Eren-Koçak E, Sen ZD, Dalkara T. Spreading depression triggers headache by activating neuronal Panx1 channels. Science 2013; 339:1092-5. [PMID: 23449592 DOI: 10.1126/science.1231897] [Citation(s) in RCA: 337] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The initial phase in the development of a migraine is still poorly understood. Here, we describe a previously unknown signaling pathway between stressed neurons and trigeminal afferents during cortical spreading depression (CSD), the putative cause of migraine aura and headache. CSD caused neuronal Pannexin1 (Panx1) megachannel opening and caspase-1 activation followed by high-mobility group box 1 (HMGB1) release from neurons and nuclear factor κB activation in astrocytes. Suppression of this cascade abolished CSD-induced trigeminovascular activation, dural mast cell degranulation, and headache. CSD-induced neuronal megachannel opening may promote sustained activation of trigeminal afferents via parenchymal inflammatory cascades reaching glia limitans. This pathway may function to alarm an organism with headache when neurons are stressed.
Collapse
Affiliation(s)
- Hulya Karatas
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | | | | | | | | | | | | |
Collapse
|
49
|
Sevgi EB, Erdener SE, Demirci M, Topcuoglu MA, Dalkara T. Paradoxical air microembolism induces cerebral bioelectrical abnormalities and occasionally headache in patent foramen ovale patients with migraine. J Am Heart Assoc 2012; 1:e001735. [PMID: 23316313 PMCID: PMC3540661 DOI: 10.1161/jaha.112.001735] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 09/18/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although controversial, paradoxical embolism via patent foramen ovale (PFO) may account for some of the migraine attacks in a subset of migraine with aura (MA) patients. Induction of MA attacks with air bubble injection during transcranial Doppler ultrasound in MA patients with PFO supports this view. It is likely that cerebral embolism in patients with right-to-left shunt induces bioelectrical abnormalities to initiate MA under some conditions. METHODS AND RESULTS We investigated changes in cerebral bioelectrical activity after intravenous microbubble injection in 10 MA patients with large PFO and right-to-left cardiac shunt. Eight PFO patients without migraine but with large right-to-left shunt and 12 MA patients without PFO served as controls. Four MA patients with PFO were reexamined with sham injections of saline without microbubbles. Bioelectrical activity was evaluated using spectral electroencephalography and, passage of microbubbles through cerebral arteries was monitored with transcranial Doppler ultrasound. Microbubble embolism caused significant electroencephalographic power increase in MA+PFO patients but not in control groups including the sham-injected MA+PFO patients. Headache developed in 2 MA with PFO patients after microbubble injection. CONCLUSIONS These findings demonstrate that air microembolism through large PFOs may cause cerebral bioelectrical disturbances and, occasionally, headache in MA patients, which may reflect an increased reactivity of their brain to transient subclinical hypoxia-ischemia, and suggest that paradoxical embolism is not a common cause of migraine but may induce headache in the presence of a large PFO and facilitating conditions.
Collapse
Affiliation(s)
- Eser Başak Sevgi
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | | | | | | | | |
Collapse
|
50
|
Dalkara T, Arsava EM. Can restoring incomplete microcirculatory reperfusion improve stroke outcome after thrombolysis? J Cereb Blood Flow Metab 2012; 32:2091-9. [PMID: 23047270 PMCID: PMC3519416 DOI: 10.1038/jcbfm.2012.139] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/31/2012] [Accepted: 09/03/2012] [Indexed: 12/27/2022]
Abstract
Substantial experimental data and recent clinical evidence suggesting that tissue reperfusion is a better predictor of outcome after thrombolysis than recanalization necessitate that patency of microcirculation after recanalization should be reevaluated. If indeed microcirculatory blood flow cannot be sufficiently reinstituted despite complete recanalization as commonly observed in coronary circulation, it may be one of the factors contributing to low efficacy of thrombolysis in stroke. Although microvascular no-reflow is considered an irreversible process that prevents tissue recovery from injury, emerging evidence suggests that it might be reversed with pharmacological agents administered early during recanalization. Therefore, therapeutic approaches aiming at reducing microvascular obstructions may improve success rate of recanalization therapies. Importantly, promoting oxygen delivery to the tissue, where entrapped erythrocytes cannot circulate in capillaries, with ongoing serum flow may improve survival of the underreperfused tissue. Altogether, these developments bring about the exciting possibility that benefit of reperfusion therapies can be further improved by restoring microcirculatory function because survival in the penumbra critically depends on adequate blood supply. Here, we review the available evidence suggesting presence of an 'incomplete microcirculatory reperfusion' (IMR) after focal cerebral ischemia and discuss potential means that may help investigate IMR in stroke patients after recanalization therapies despite technical limitations.
Collapse
Affiliation(s)
- Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| | | |
Collapse
|