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1.
Transl Stroke Res ; 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32378028

RESUMO

Adipose-derived mesenchymal stem cells markedly attenuated brain infarct size and improved neurological function in rats. The mechanisms for neuronal cell death have previously been defined in stress states to suggest that an influx of calcium ions into the neurons activates calpain cleavage of p35 into p25 forming a hyperactive complex that induces cell death. Now we report that p5, a 24-residue peptide derived from p35, offers protection to neurons and endothelial cells in vitro. In vivo administration of human adipose-derived mesenchymal stem cells (hADMSCs) loaded with this therapeutic peptide to post-stroke rats had no effect on the infarct volume. Nevertheless, the treatment led to improvement in functional recovery in spatial learning and memory (water maze), bilateral coordination and sensorimotor function (rotating pole), and asymmetry of forelimb usage (cylinder test). However, the treatment may not impact on cutaneous sensitivity (adhesive tape removal test). In addition, the double immunofluorescence with human cell-specific antibodies revealed that the number of surviving transplanted cells was higher in the peri-infarcted area of animals treated with hADMSCs + P5 than that in hADMSC-treated or control animals, concomitant with reduced number of phagocytic, annexin3-positive cells in the peri-infarcted region. However, the combination therapy did not increase the vascular density in the peri-infarcted area after stroke. In conclusion, administration of hADMSC-loaded p5 peptide to post-stroke rats created conditions that supported survival of drug-loaded hADMSCs after cerebral ischemia, suggesting its therapeutic potential in patients with stroke.

2.
Acta Biomater ; 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32413579

RESUMO

The neurovascular unit (NVU) is a complex functional and anatomical structure composed of endothelial cells and their blood-brain barrier (BBB) forming tight junctions. It represents an efficient barrier for molecules and drugs. However, it also prevents a targeted transport for the treatment of cerebral diseases. The uptake of ultrasmall nanoparticles as potential drug delivery agents was studied in a three-dimensional co-culture cell model (3D spheroid) composed of primary human cells (astrocytes, pericytes, endothelial cells). Multicellular 3D spheroids show reproducible NVU features and functions. The spheroid core is composed mainly of astrocytes, covered with pericytes, while brain endothelial cells form the surface layer, establishing the NVU that regulates the transport of molecules. After 120 h cultivation, the cells self-assemble into a 350 µm spheroid as shown by confocal laser scanning microscopy. The passage of different types of fluorescent ultrasmall gold nanoparticles (core diameter 2 nm) both into the spheroid and into three constituting cell types was studied by confocal laser scanning microscopy. Three kinds of covalently fluorophore-conjugated gold nanoparticles were used: One with fluorescein (FAM), one with Cy3, and one with the peptide CGGpTPAAK-5,6-FAM-NH2. In 2D cell co-culture experiments, it was found that all three kinds of nanoparticles readily entered all three cell types. FAM- and Cy3-labelled nanoparticles were able to enter the cell nucleus as well. The three dissolved dyes alone were not taken up by any cell type. A similar situation evolved with 3D spheroids: The three kinds of nanoparticles entered the spheroid, but the dissolved dyes did not. The presence of a functional blood-brain barrier was demonstrated by adding histamine to the spheroids. In that case, the blood-brain barrier opened, and dissolved dyes like a FITC-labelled antibody and FITC alone entered the spheroid. In summary, our results qualify ultrasmall gold nanoparticles as suitable carriers for imaging or drug delivery into brain cells (sometimes including the nucleus), brain cell spheroids, and probably also into the brain. Statement of Significance 3D brain spheroid model and its permeability by ultrasmall gold nanoparticles. We demonstrate that ultrasmall gold nanoparticles can easily penetrate the constituting cells and sometimes even enter the cell nucleus. They can also enter the interior of the blood-brain barrier model. In contrast, small molecules like fluorescing dyes are not able to do that. Thus, ultrasmall gold nanoparticles can serve as carriers of drugs or for imaging inside the brain.

4.
Geroscience ; 2020 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-32285289

RESUMO

Let alone calorie restriction, life span extension in higher organisms has proven to be difficult to achieve using simple drugs. Previous studies have shown that the polyamine spermidine increased the maximum life span in C. elegans and the median life span in mice. However, younger subjects (< 40 years of age) are infrequently prescribed nor self-medicating with antiaging drugs. Therefore, in the present study, we aimed at assessing the effect of long-term treatment with spermidine given in the drinking water on behavioral performance and longevity of male, middle-aged Sprague-Dawley rats. We report that spermidine given in the drinking water did not extend neither the median nor the maximum life span of the middle-aged male Sprague-Dawley rats. However, spermidine treatment had a beneficial effect on the body weight and the kidney tubules, liver, and heart morphology. Behaviorally, spermidine led to a reduction in anxiety and an increase in curiosity, as assessed by exploratory behavior. Moreover, long-term treatment with spermidine enhanced autophagy in the brain and led to a diminished expression of the inflammatory markers, Tgfb, CD11b, Fcgr1, Stat1, CR3, and GFAP mRNAs in several cortical region and hippocampus of the treated rats suggesting that one beneficial effect of the long-term treatment with spermidine is an attenuated proinflammatory state in the aged brain. Our results suggest that long-term treatment with spermidine increases health span of middle-aged rats by attenuating neuroinflammation and improving anxiety and exploratory behavior.

5.
Stroke ; : STROKEAHA119028012, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32312217

RESUMO

Background and Purpose- Small extracellular vesicles (sEVs) obtained from mesenchymal stromal cells (MSCs) were shown to induce neurological recovery after focal cerebral ischemia in rodents and to reverse postischemic lymphopenia in peripheral blood. Since peripheral blood cells, especially polymorphonuclear neutrophils (PMNs), contribute to ischemic brain injury, we analyzed brain leukocyte responses to sEVs and investigated the role of PMNs in sEV-induced neuroprotection. Methods- Male C57Bl6/j mice were exposed to transient intraluminal middle cerebral artery occlusion. After reperfusion, vehicle or sEVs prepared from conditioned media of MSCs raised from bone marrow samples of 3 randomly selected healthy human donors were intravenously administered. sEVs obtained from normoxic and hypoxic MSCs were applied. PMNs were depleted in vehicle and MSC-sEV-treated mice. Neurological deficits, ischemic injury, blood-brain barrier integrity, peripheral blood leukocyte responses, and brain leukocyte infiltration were evaluated over 72 hours. Results- sEV preparations of all 3 donors collected from normoxic MSCs significantly reduced neurological deficits. Preparations of 2 of these donors significantly decreased infarct volume and neuronal injury. sEV-induced neuroprotection was consistently associated with a decreased brain infiltration of leukocytes, namely of PMNs, monocytes/macrophages, and lymphocytes. sEVs obtained from hypoxic MSCs (1% O2) had similar effects on neurological deficits and ischemic injury as MSC-sEVs obtained under regular conditions (21% O2) but also reduced serum IgG extravasation-a marker of blood-brain barrier permeability. PMN depletion mimicked the effects of MSC-sEVs on neurological recovery, ischemic injury, and brain PMN, monocyte, and lymphocyte counts. Combined MSC-sEV administration and PMN depletion did not have any effects superior to PMN depletion in any of the readouts examined. Conclusions- Leukocytes and specifically PMNs contribute to MSC-sEV-induced ischemic neuroprotection. Individual MSC-sEV preparations may differ in their neuroprotective activities. Potency assays are urgently needed to identify their therapeutic efficacy before clinical application.

6.
Heart ; 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165451

RESUMO

OBJECTIVE: To examine how different aspects of social relationships are associated with incident cardiovascular events and all-cause mortality. METHODS: In 4139 participants from the population-based Heinz Nixdorf Recall study without previous cardiovascular disease (mean (SD) age 59.1 (7.7) years, 46.7% men), the association of self-reported instrumental, emotional and financial support and social integration at baseline with incident fatal and non-fatal cardiovascular events and all-cause mortality during 13.4-year follow-up was assessed in five different multivariable Cox proportional hazards regression models: minimally adjusted model (adjusting for age, sex, social integration or social support, respectively); biological model (minimally adjusted+systolic blood pressure, low-density and high-density lipoprotein cholesterol, glycated haemoglobin, body mass index, antihypertensive medication, lipid-lowering medication and antidiabetic medication); health behaviour model (minimally adjusted+alcohol consumption, smoking and physical activity); socioeconomic model (minimally adjusted+income, education and employment); and depression model (minimally adjusted+depression, antidepressants and anxiolytics). RESULTS: 339 cardiovascular events and 530 deaths occurred during follow-up. Lack of financial support was associated with an increased cardiovascular event risk (minimally adjusted HR=1.30(95% CI 1.01 to 1.67)). Lack of social integration (social isolation) was associated with increased mortality (minimally adjusted HR=1.47 (95% CI 1.09 to 1.97)). Effect estimates did not decrease to a relevant extent in any regression model. CONCLUSIONS: Perceiving a lack of financial support is associated with a higher cardiovascular event incidence, and being socially isolated is associated with increased all-cause mortality. Future studies should investigate how persons with deficient social relationships could benefit from targeted interventions.

7.
J Neuroimmunol ; 342: 577216, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32199198

RESUMO

Regulatory T cells (Treg) maintain immunological self-tolerance and their functional or numerical deficits are associated with progression of several neurological diseases. We examined the effects of Treg absence on the structure and integrity of the unchallenged murine brain. When compared to control, Treg-deficient FoxP3sf mutant mice showed no differences in brain size, myelin amount and oligodendrocyte numbers. FoxP3sf strain displayed no variations in quantity of neurons and astrocytes, whereas microglia numbers were slightly reduced. We demonstrate lack of neuroinflammation and parenchymal responses in the brains of Treg-deficient mice, suggesting a minor Treg role in absence of blood-brain barrier breakdown.

8.
Trials ; 21(1): 136, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32014032

RESUMO

BACKGROUND: The GABAA-α5 receptor antagonist S44819 is a promising candidate to enhance functional recovery after acute ischemic stroke (IS). S44819 is currently evaluated in this indication; RESTORE brain study started in Dec 2016 and was completed in March 2019. METHODS/DESIGN: The study is a 3-month international, randomized, double-blind, parallel group, placebo-controlled phase II multicentre study. Patients in 14 countries who suffered an IS leading to a moderate or severe deficit defined by NIHSS score ranging from 7 to 20 and are aged between 18 to 85 years are included between 3 and 8 days after the stroke onset. Approximately 580 patients are to be included. The primary objective of the study is to demonstrate the superiority of at least one of the two doses of S44819 (150 or 300 mg bid) compared to placebo on top of usual care on functional recovery measured with the modified Rankin scale at 3 months. Comparisons between two doses of S44819 and placebo are assessed with ordinal logistic regression evaluating the odds of shifting from one category to the next in the direction of a better outcome at day 90. Secondary objectives include the evaluation of S44819 effects on neurological examination using the National Institute of Health Stroke Scale total score, activities of daily living using the Barthel Index total score, and cognitive performance using the Montreal Cognitive Assessment scale total score and Trail Making Test times. Safety and tolerability of the two doses of S44819 will also be analyzed. DISCUSSION: The RESTORE BRAIN study might represent the first proof of concept study of an innovative therapeutic approach that is primarily based on enhancing functional recovery after IS. TRIAL REGISTRATION: Randomized Efficacy and Safety Trial with Oral S 44819 after Recent ischemic cerebral Event, an international, multi-centre, randomized, double-blind placebo-controlled phase II study. ClinicalTrials.gov, NCT02877615; Eudract 2016-001005-16. Registered 24 August 2016.

9.
Lancet Neurol ; 19(3): 226-233, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32085836

RESUMO

BACKGROUND: S44819, a selective GABAA α5 receptor antagonist, reduces tonic post-ischaemic inhibition of the peri-infarct cortex. S44819 improved stroke recovery in rodents and increased cortical excitability in a transcranial magnetic stimulation study in healthy volunteers. The Randomized Efficacy and Safety Trial of Oral GABAA α5 antagonist S44819 after Recent ischemic Event (RESTORE BRAIN) aimed to evaluate the safety and efficacy of S44819 for enhancing clinical recovery of patients with ischaemic stroke. METHODS: RESTORE BRAIN was an international, randomised, double-blind, parallel-group, placebo-controlled, multicentre phase 2 trial that evaluated the safety and efficacy of oral S44189 in patients with recent ischaemic stroke. The study was done in specialised stroke units in 92 actively recruiting centres in 14 countries: ten were European countries (Belgium, Czech Republic, France, Germany, Hungary, Italy, Netherlands, Poland, Spain, and the UK) and four were non-European countries (Australia, Brazil, Canada, and South Korea). Patients aged 18-85 years with acute ischaemic stroke involving cerebral cortex (National Institute of Health Stroke Scale [NIHSS] score 7-20) without previous disability were eligible for inclusion. Participants were randomly assigned to receive 150 mg S44819 twice a day, 300 mg S44819 twice a day, or placebo twice a day by a balanced, non-adaptive randomisation method with a 1:1:1 ratio. Treatment randomisation and allocation were centralised via the interactive web response system using computer-generated random sequences with a block size of 3. Blinding of treatment was achieved by identical appearance and taste of all sachets. Patients, investigators and individuals involved in the analysis of the trial were masked to group assignment. The primary endpoint was the modified Rankin Scale (mRS) score 90 days from onset of treatment, evaluated by shift analysis (predefined main analysis) or by dichotomised analyses using 0-1 versus 2-6 and 0-2 versus 3-6 cutoffs (predefined secondary analysis). Secondary endpoints were the effects of S44819 on the NIHSS and Montreal Cognitive Assessment (MoCA) scores, time needed to complete parts A and B of the Trail Making Test, and the Barthel index. Efficacy analyses were done on all patients who received at least one dose of treatment and had at least one mRS score taken after day 5 (specifically, on or after day 30). Safety was compared across treatment groups for all patients who received at least one dose of treatment. The study was registered at ClinicalTrials.gov, NCT02877615. FINDINGS: Between Dec 19, 2016, and Nov 16, 2018, 585 patients were enrolled in the study. Of these, 197 (34%) were randomly assigned to receive 150 mg S44819 twice a day, 195 (33%) to receive 300 mg S44819 twice a day, and 193 (33%) to receive placebo twice a day. 189 (96%) of 197 patients in the 150 mg S44819 group, 188 (96%) of 195 patients in the 300 mg S44819 group, and 191 (99%) patients in the placebo group received at least one dose of treatment and had at least one mRS score taken after day 5, and were included in efficacy analyses. 195 (99%) of 197 patients in the 150 mg S44819 group, 194 (99%) of 195 patients in the 300 mg S44819 group, and 193 (100%) patients in the placebo group received at least one dose of treatment, and were included in safety analyses. The primary endpoint of mRS at day 90 did not differ between each of the two S44819 groups and the placebo group (OR 0·91 [95% CI 0·64-1·31]; p=0·80 for 150 mg S44819 compared with placebo and OR 1·17 [95% CI 0·81-1·67]; p=0·80 for 300 mg S44819 compared with placebo). Likewise, dichotomised mRS scores at day 90 (mRS 0-2 vs 3-6 or mRS 0-1 vs 2-6) did not differ between groups. Secondary endpoints did not reveal any significant group differences. The median NIHSS score at day 90 did not differ between groups (4 [IQR 2-8] in 150 mg S44819 group, 4 [2-7] in 300 mg S44819 group, and 4 [2-6] in placebo group), nor did the number of patients at day 90 with an NIHSS score of up to 5 (95 [61%] of 156 in 150 mg S44819 group, 106 [66%] of 161 in 300 mg S44819 group, and 104 [66%] of 157 in placebo group) versus more than 5 (61 [39%] in 150 mg S44819 group, 55 [34%] in 300 mg S44819 group, and 53 [34%] in placebo group). Likewise, the median MoCA score (22·0 [IQR 17·0-26·0] in 150 mg S44819 group, 23·0 [19·0-26·5] in 300 mg S44819 group, and 22·0 [17·0-26·0] in placebo group), time needed to complete parts A (50 s [IQR 42-68] in 150 mg S44819 group, 49 s [36-63] in 300 mg S44819 group, and 50 s [38-68] in placebo group) and B (107 s [81-144] in 150 mg S44819 group, 121 s [76-159] in 300 mg S44819 group, and 130 s [86-175] in placebo group) of the Trail Making Test, and the Barthel index (90 [IQR 60-100] in 150 mg S44819 group, 90 [70-100] in 300 mg S44819 group, and 90 [70-100] in placebo group) were similar in all groups. Number and type of adverse events were similar between the three groups. There were no drug-related adverse events and no drug-related deaths. INTERPRETATION: There was no evidence that S44819 improved clinical outcome in patients after ischaemic stroke, and thus S44819 cannot be recommended for stroke therapy. The concept of tonic inhibition after stroke should be re-evaluated in humans. FUNDING: Servier.

10.
BMC Geriatr ; 20(1): 75, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32085737

RESUMO

BACKGROUND: The rising number of older multimorbid in-patients has implications for medical care. There is a growing need for the identification of factors predicting the needs of older patients in hospital environments. Our aim was to evaluate the use of clinical and functional patient characteristics for the prediction of medical needs in older hospitalized patients. METHODS: Two hundred forty-two in-patients (57.4% male) aged 78.4 ± 6.4 years, who were consecutively admitted to internal medicine departments of the University Hospital Essen between July 2015 and February 2017, were prospectively enrolled. Patients were assessed upon admission using the Identification of Seniors at Risk (ISAR) screening followed by comprehensive geriatric assessment (CGA). The CGA included standardized instruments for the assessment of activities of daily living (ADL), cognition, mobility, and signs of depression upon admission. In multivariable regressions we evaluated the association of clinical patient characteristics, the ISAR score and CGA results with length of hospital stay, number of nursing hours and receiving physiotherapy as indicators for medical needs. We identified clinical characteristics and risk factors associated with higher medical needs. RESULTS: The 242 patients spent [median(Q1;Q3)]:9.0(4.0;16.0) days in the hospital, needed 2.0(1.5;2.7) hours of nursing each day, and 34.3% received physiotherapy. In multivariable regression analyses including clinical patient characteristics, ISAR and CGA domains, the factors age (ß = - 0.19, 95% confidence interval (CI) = - 0.66;-0.13), number of admission diagnoses (ß = 0.28, 95% CI = 0.16;0.41), ADL impairment (B = 6.66, 95% CI = 3.312;10.01), and signs of depression (B = 6.69, 95% CI = 1.43;11.94) independently predicted length of hospital stay. ADL impairment (B = 1.14, 95%CI = 0.67;1.61), cognition impairment (B = 0.57, 95% CI = 0.07;1.07) and ISAR score (ß =0.26, 95% CI = 0.01;0.28) independently predicted nursing hours. The number of admission diagnoses (risk ratio (RR) = 1.06, 95% CI = 1.04;1.08), ADL impairment (RR = 3.54, 95% CI = 2.29;5.47), cognition impairment (RR = 1.77, 95% CI = 1.20;2.62) and signs of depression (RR = 1.99, 95% CI = 1.39;2.85) predicted receiving physiotherapy. CONCLUSION: Among older in-patients at risk for functional decline, the number of comorbidities, reduced ADL, cognition impairment and signs of depression are important predictors of length of hospital stay, nursing hours, and receiving physiotherapy during hospital stay.

11.
J Neuroinflammation ; 17(1): 9, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31915017

RESUMO

BACKGROUND: The multi-drug resistance transporter ABCG2, a member of the ATP-binding cassette (ABC) transporter family, mediates the efflux of different immunotherapeutics used in multiple sclerosis (MS), e.g., teriflunomide (teri), cladribine, and mitoxantrone, across cell membranes and organelles. Hence, the modulation of ABCG2 activity could have potential therapeutic implications in MS. In this study, we aimed at investigating the functional impact of abcg2 modulation on teri-induced effects in vitro and in vivo. METHODS: T cells from C57BL/6 J wild-type (wt) and abcg2-knockout (KO) mice were treated with teri at different concentrations with/without specific abcg2-inhibitors (Ko143; Fumitremorgin C) and analyzed for intracellular teri concentration (HPLC; LS-MS/MS), T cell apoptosis (annexin V/PI), and proliferation (CSFE). Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6J by active immunization with MOG35-55/CFA. Teri (10 mg/kg body weight) was given orally once daily after individual disease onset. abcg2-mRNA expression (spinal cord, splenic T cells) was analyzed using qRT-PCR. RESULTS: In vitro, intracellular teri concentration in T cells was 2.5-fold higher in abcg2-KO mice than in wt mice. Teri-induced inhibition of T cell proliferation was two fold increased in abcg2-KO cells compared to wt cells. T cell apoptosis demonstrated analogous results with 3.1-fold increased apoptosis after pharmacological abcg2-inhibition in wt cells. abcg2-mRNA was differentially regulated during different phases of EAE within the central nervous system and peripheral organs. In vivo, at a dosage not efficacious in wt animals, teri treatment ameliorated clinical EAE in abcg2-KO mice which was accompanied by higher spinal cord tissue concentrations of teri. CONCLUSION: Functional relevance of abcg2 modulation on teri effects in vitro and in vivo warrants further investigation as a potential determinant of interindividual treatment response in MS, with potential implications for other immunotherapies.

12.
Transl Stroke Res ; 11(1): 135-146, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30887279

RESUMO

Malnutrition predisposes to poor stroke outcome. In animal models, undernutrition protected against ischemic injury in some, but not in other studies. In view of diverse stroke models and food restriction paradigms, the consequences of undernutrition are poorly understood. Herein, we exposed mice to energy-reduced and protein-energy-reduced diets for 7-30 days and subsequently induced intraluminal middle cerebral artery occlusion. Undernutrition phase dependently influenced ischemic injury. Short-lasting 7 days of protein-energy undernutrition, but not energy undernutrition, decreased post-ischemic brain leukocyte infiltration and microglial activation and reduced brain Il-1ß mRNA, but did not protect against ischemic injury. Fourteen days of energy and protein-energy undernutrition, on the other hand, reduced ischemic injury despite absence of anti-inflammatory effects. Anti-oxidant genes (Sod-1, Sod-2, and Cat mRNAs) were regulated in the liver and, to a lesser extent, the ischemic brain, indicating an adapted, compensated stage. Conversely, 30 days of energy and protein-energy undernutrition caused progressive animal exhaustion associated with post-ischemic hypoperfusion, rise of metabolic markers (Sirt-1 and Glut-1 mRNAs, Sirt-1 protein) in the ischemic brain, and reregulation of pro- and anti-oxidant markers (now also Nox-4 and Gpx-3 mRNAs) in the liver. In the latter condition, no neuroprotection was noted. Our study suggests an adaptation of metabolic systems that provides neuroprotection in a circumscribed time window.

13.
Geroscience ; 42(1): 373, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31776884

RESUMO

Unfortunately, the name of the second author was incorrectly captured in the published online paper.

14.
Neurobiol Aging ; 85: 154.e5-154.e7, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31500908

RESUMO

In the present study, a novel mutation in the presenilin 1 gene was discovered in an Iraq-native patient with early-onset Alzheimer's disease, who presented with speech impairment and memory decline at age 46 years. Magnetic resonance imaging showed a frontotemporal atrophy. Sanger sequencing identified a heterozygous T to A transversion at position 815 (c.815T>A) in the presenilin 1 gene (PSEN1), resulting in a novel missense mutation at codon 272 from valine to aspartate (V272D). We tested this PSEN1 mutation in vitro and found V272D resulted in an altered Aß42/40 ratio.

15.
Int J Mol Sci ; 20(23)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31795466

RESUMO

Following the failure of acute neuroprotection therapies, major efforts are currently made worldwide to promote neurological recovery and brain plasticity in the subacute and post-acute phases of stroke. Currently, there is hope that stroke recovery might be promoted by cell-based therapies. The field of stem cell therapy for cerebral ischemia has made significant progress in the last five years. A variety of stem cells have been tested in animal models and humans including adipose stem cells, human umbilical cord blood-derived mesenchymal stem cells, human amnion epithelial cells, human placenta amniotic membrane-derived mesenchymal stem cells, adult human pluripotent-like olfactory stem cells, human bone marrow endothelial progenitor cells, electrically-stimulated human neuronal progenitor cells, or induced pluripotent stem cells (iPSCs) of human origin. Combination therapies in animal models include a mix of two or more therapeutic factors consisting of bone marrow stromal cells, exercise and thyroid hormones, endothelial progenitor cells overexpressing the chemokine CXCL12. Mechanisms underlying the beneficial effects of transplanted cells include the "bystander" effects, paracrine mechanisms, or extracellular vesicles-mediated restorative effects. Mitochondria transfer also appears to be a powerful strategy for regenerative processes. Studies in humans are currently limited to a small number of studies using autologous stem cells mainly aimed to assess tolerability and side-effects of human stem cells in the clinic.

16.
Neural Plast ; 2019: 1071036, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31814819

RESUMO

Worldwide, millions of individuals suffer an ischemic stroke each year, causing major disability, especially in the elderly, where stroke is the number one cause of disability. However, to date, no effective therapy exists that targets the functional recovery after stroke. After necrosis, neuroinflammation is a common feature of the acute stroke and a major obstacle to tissue restoration. In the lesioned area, the dying neurons release chemotactic signals, such as fractalkine/CX3CL1, which evoke "eat-me" signals that are recognized by microglia expressing complement C3a receptor (C3aR), resulting in phagocytosis of the dying but still viable neurons, known as secondary phagocytosis. Using a mouse model of stroke and two-photon microscopy, we aimed to attenuate poststroke phagocytosis of the dying but still viable neurons by using SB 290157, an antagonist of C3aR. We found that intracortical administration of SB 290157 reduced the number of inflammatory microglial cells expressing ED1 and Iba1 antigens at the lesion site. We could show, in vivo, that two days after a needle-induced cortical lesion there were less microglial cells present around the injury site, displaying less high-order branches and an increase in the lower order ones, suggesting an attenuated phagocytic phenotype in treated animals as compared with controls. We conclude that the C3aR antagonist, SB 290157, may be used in the future to limit the neuronal death by limiting secondary phagocytosis after stroke.

17.
Neural Plast ; 2019: 9785476, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827502

RESUMO

Major efforts are currently made promoting neuronal plasticity and brain remodeling in the postacute stroke phase. Experimental studies evaluating new stroke therapies are mostly performed in rodents, which compared to humans exhibit a short lifespan. These studies widely employ young, otherwise healthy, rodents that lack the vascular risk factors and comorbidities of stroke patients. These risk factors compromise postischemic neurological recovery and brain plasticity and in several contexts reduce the brain responsiveness to recovery-inducing plasticity-promoting treatments. By examining risk factor models, which have hitherto been used for studying experimentally induced ischemic stroke, this review outlines the possibilities and limitations of risk factor models in the evaluation of plasticity-promoting and restorative stroke treatments.

18.
Neurosignals ; 27(S1): 32-43, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31778304

RESUMO

In this review, we summarize implications of the acid sphingomyelinase/ ceramide system in ischemic stroke. Acid sphingomyelinase catalyzes the formation of the bioactive sphingolipid ceramide which coalesces into membrane platforms and has a pivotal role in inflammation, cell signaling and death. Cerebral ischemia increases acid sphingomyelinase activity and elevates brain ceramide levels, which has been associated with the exacerbation of ischemic injury and deterioration of stroke outcome. In view of the fact that lowering acid sphingomyelinase activity and ceramide level was shown to protect against ischemic injury and ameliorate neurological deficits, the acid sphingomyelinase/ ceramide system might represent a promising target for stroke therapies.

19.
Hypertension ; 74(6): 1436-1447, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31679426

RESUMO

Arterial hypertension promotes atherosclerosis and cardiovascular events. We evaluated how cardiovascular risk and atherosclerosis progression are associated with blood pressure, antihypertensive treatment, and treatment efficacy. In 3555 participants of the population-based Heinz Nixdorf Recall study without previous cardiovascular disease (mean±SD; age, 58.9±7.6 years, 46.9% men), we analyzed associations of baseline antihypertensive treatment efficacy (normotension without antihypertensives, normotension with antihypertensives, hypertension without antihypertensives, hypertension with antihypertensives, based on 140/90 mmHg cutoffs) with incident coronary artery calcification (CAC) and CAC progression during 5-year-follow-up and with incident cardiovascular events during 13.5-year-follow-up. We further evaluated associations of incident arterial hypertension and efficacy of new antihypertensive treatment at the 5-year-follow-up with subsequent cardiovascular events. At baseline, 1706 participants had normotension without antihypertensives, 553 normotension with antihypertensives, 786 hypertension without antihypertensives, and 510 hypertension with antihypertensives. Six hundred forty-seven participants experienced rapid CAC progression. One hundred seven, 132, and 249 had incident stroke, coronary event, and cardiovascular event, respectively. Compared with normotensives without antihypertensives, normotensives with antihypertensives had an elevated stroke (hazard ratio, 2.33 [95% CI, 1.19-4.55]), coronary (2.04 [95% CI, 1.20-3.45]), and cardiovascular (2.23 [95% CI, 1.48-3.36]) risk, and increased baseline CAC, but not increased CAC progression. Participants without hypertension at baseline, who were newly hypertensive but achieved normotension with antihypertensives at the 5-year-follow-up, again exhibited elevated stroke (4.80 [95% CI, 1.38-16.70]) and cardiovascular (2.99 [95% CI, 1.25-7.16]) risk, whereas coronary risk was less elevated (2.24 [95% CI, 0.70-7.18]). Normotensives with antihypertensives have an elevated cardiovascular risk. They are characterized by elevated baseline CAC but show no signs of increased CAC progression.

20.
Front Cell Neurosci ; 13: 412, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31572128

RESUMO

ATP-binding cassette (ABC) transporters prevent the access of pharmacological compounds to the ischemic brain, thereby impeding the efficacy of stroke therapies. ABC transporters can be deactivated by selective inhibitors, which potently increase the brain accumulation of drugs. Concerns have been raised that long-term ABC transporter deactivation may promote neuronal degeneration and, under conditions of ischemic stroke, compromise neurological recovery. To elucidate this issue, we exposed male C57BL/6 mice to transient intraluminal middle cerebral artery occlusion (MCAO) and examined the effects of the selective ABCB1 inhibitor tariquidar (8 mg/kg/day) or ABCC1 inhibitor MK-571 (10 mg/kg/day), which were administered alone or in combination with each other over up to 28 days, on neurological recovery and brain injury. Mice were sacrificed after 14, 28, or 56 days. The Clark score, RotaRod, tight rope, and open field tests revealed reproducible motor-coordination deficits in mice exposed to intraluminal MCAO, which were not influenced by ABCB1, ABCC1, or combined ABCB1 and ABCC1 deactivation. Brain volume, striatum volume, and corpus callosum thickness were not altered by ABCB1, ABCC1 or ABCB1, and ABCC1 inhibitors. Similarly, neuronal survival and reactive astrogliosis, evaluated by NeuN and GFAP immunohistochemistry in the ischemic striatum, were unchanged. Iba1 immunohistochemistry revealed no changes of the overall density of activated microglia in the ischemic striatum of ABC transporter inhibitor treated mice, but subtle changes of microglial morphology, that is, reduced microglial cell volume by ABCB1 deactivation after 14 and 28 days and reduced microglial ramification by ABCB1, ABCC1 and combined ABCB1 and ABCC1 deactivation after 56 days. Endogenous neurogenesis, assessed by BrdU incorporation analysis, was not influenced by ABCB1, ABCC1 or combined ABCB1 and ABCC1 deactivation. Taken together, this study could not detect any exacerbation of neurological deficits or brain injury after long-term ABC transporter deactivation in this preclinical stroke model.

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