Differential effects of the cell cycle inhibitor, olomoucine, on functional recovery and on responses of peri-infarct microglia and astrocytes following photothrombotic stroke in rats

Abstract Background Following stroke, changes in neuronal connectivity in tissue surrounding the infarct play an important role in both spontaneous recovery of neurological function and in treatment-induced improvements in function. Microglia and astrocytes influence this process through direct interactions with the neurons and as major determinants of the local tissue environment. Subpopulations of peri-infarct glia proliferate early after stroke providing a possible target to modify recovery. Treatment with cell cycle inhibitors can reduce infarct volume and improve functional recovery. However, it is not known whether these inhibitors can influence neurological function or alter the responses of peri-infarct glia without reducing infarction. The present study aimed to address these issues by testing the effects of the cell cycle inhibitor, olomoucine, on recovery and peri-infarct changes following photothrombotic stroke. Methods Stroke was induced by photothrombosis in the forelimb sensorimotor cortex in Sprague-Dawley rats. Olomoucine was administered at 1 h and 24 h after stroke induction. Forelimb function was monitored up to 29 days. The effects of olomoucine on glial cell responses in peri-infarct tissue were evaluated using immunohistochemistry and Western blotting. Results Olomoucine treatment did not significantly affect maximal infarct volume. Recovery of the affected forelimb on a placing test was impaired in olomoucine-treated rats, whereas recovery in a skilled reaching test was substantially improved. Olomoucine treatment produced small changes in aspects of Iba1 immunolabelling and in the number of CD68-positive cells in cerebral cortex but did not selectively modify responses in peri-infarct tissue. The content of the astrocytic protein, vimentin, was reduced by 30% in the region of the lesion in olomoucine-treated rats. Conclusions Olomoucine treatment modified functional recovery in the absence of significant changes in infarct volume. The effects on recovery were markedly test dependent, adding to evidence that skilled tasks requiring specific training and general measures of motor function can be differentially modified by some interventions. The altered recovery was not associated with specific changes in key responses of peri-infarct microglia, even though these cells were considered a likely target for early olomoucine treatment. Changes detected in peri-infarct reactive astrogliosis could contribute to the altered patterns of functional recovery.

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Suppression of astroglial scar formation and enhanced axonal regeneration associated with functional recovery in a spinal cord injury rat model by the cell cycle inhibitor olomoucine

Journal of Neuroscience Research ◽

10.1002/jnr.20999 ◽

2006 ◽

Vol 84 (5) ◽

pp. 1053-1063 ◽

Cited By ~ 68

Author(s):

Dai-Shi Tian ◽

Zhi-Yuan Yu ◽

Min-Jie Xie ◽

Bi-Tao Bu ◽

Otto W. Witte ◽

...

Keyword(s):

Cell Cycle ◽

Spinal Cord ◽

Spinal Cord Injury ◽

Functional Recovery ◽

Rat Model ◽

Axonal Regeneration ◽

Scar Formation ◽

Cell Cycle Inhibitor ◽

Cord Injury

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Abstract W P89: Functional Recovery Depends on Donor Age after Stem Cell Transplantation for Stroke

Stroke ◽

10.1161/str.46.suppl_1.wp89 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Susumu Yamaguchi ◽

Nobutaka Horie ◽

Katsuya Satoh ◽

Noriyuki Nishida ◽

Izumi Nagata

Keyword(s):

Stem Cell ◽

Cerebral Ischemia ◽

Cell Transplantation ◽

Functional Recovery ◽

Cell Activation ◽

Histological Analysis ◽

Infarct Volume ◽

Human Mesenchymal Stem Cells ◽

Donor Age ◽

Sprague Dawley

Introduction: Cell transplantation therapy hold great potential to improve impairments after cerebral ischemia. However, it is still unclear whether the donor age affects functional recovery after cerebral ischemia. Here, we investigate the hypothesis that donor age (young vs. old) drastically affects the repair mechanism after cell transplantation for stroke. Materials and methods: Male Sprague Dawley rats were subjected to transient middle cerebral artery occlusion. At 24 hours after stroke, rats were randomly assigned to receive PBS (control), human mesenchymal stem cells (MSC) derived from 24 years old man (young MSC) and MSC derived from 64 years old man (old MSC) via internal carotid artery. Behavioral recovery was assessed with modified Neurological severity score (mNSS) until 21 days after stroke. Animals were euthanized at 21 days, and histological analysis was performed regarding inflammatory reaction, neovascularization and endogenous stem cell activation. Result: Young MSC showed an significant recovery in mNSS (3.7±0.6) compared with control (6.1±0.5) and old MSC (5.2±0.7) at 21 days after stroke (P<0.01). In histological analysis, infarct volume was not significantly different among the groups. However, IBA-1 positive microglia was significantly inhibited in young MSC (9.3±5.9%) compared with control (22.1±13.1%) and old MSC (15.2%±14.2%) both in the peri-infarct cortex and striatum (P<0.01). Moreover, RECA-1 positive vessels significantly increased in young MSC (5.4±1.1%) compared with control (5.0±1.6%) and old MSC (4.6%±1.5%) in the peri-infarct cortex (P<0.01). Interestingly, Young MSC showed massive GFAP positive reactive astrocyte running radially into the peri-infarct area with Musashi-1 (Msi-1) positive neural progenitor cells. Conclusion: Donor age drastically affect the host environment, endogenous progenitor cell activation and functional recovery after cell transplantation for stroke.

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Notoginsenoside R1 Improves Cerebral Ischemia/Reperfusion Injury by Promoting Neurogenesis via the BDNF/Akt/CREB Pathway

Frontiers in Pharmacology ◽

10.3389/fphar.2021.615998 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ting Zhu ◽

Lei Wang ◽

Weijie Xie ◽

Xiangbao Meng ◽

Yicheng Feng ◽

...

Keyword(s):

Ischemic Stroke ◽

Functional Recovery ◽

Ischemia Reperfusion Injury ◽

Infarct Volume ◽

Ischemia Reperfusion ◽

Neurological Function ◽

Long Term Effects ◽

Bdnf Expression ◽

Neuroprotective Effects

Notoginsenoside R1 (R1), a major component isolated from P. notoginseng, is a phytoestrogen that exerts many neuroprotective effects in a rat model of ischemic stroke. However, its long-term effects on neurogenesis and neurological restoration after ischemic stroke have not been investigated. The aim of this study was to evaluate the effects of R1 on neurogenesis and long-term functional recovery after ischemic stroke. We used male Sprague-Dawley rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). R1 was administered by intraperitoneal (i.p.) injection immediately postischemia. We showed that R1 significantly decreased infarct volume and neuronal loss, restored neurological function, and stimulated neurogenesis and oligodendrogenesis in rats subjected to MCAO/R. More importantly, R1 promoted neuronal proliferation in PC12 cells in vitro. The proneurogenic effects of R1 were associated with the activation of Akt/cAMP responsive element-binding protein, as shown by the R1-induced increase in brain-derived neurotrophic factor (BDNF) expression, and with the activation of neurological function, which was partially eliminated by selective inhibitors of BDNF and PI3K. We demonstrated that R1 is a promising compound that exerts neuroprotective and proneurogenic effects, possibly via the activation of BDNF/Akt/CREB signaling. These findings offer insight into exploring new mechanisms in long-term functional recovery after R1 treatment of ischemic stroke.

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Combined Therapy With Hyperbaric Oxygen and Melatonin Effectively Reduce Brain Infarct Volume and Preserve Neurological Function After Acute Ischemic Infarct in Rat

Journal of Neuropathology & Experimental Neurology ◽

10.1093/jnen/nlz076 ◽

2019 ◽

Vol 78 (10) ◽

pp. 949-960 ◽

Cited By ~ 3

Author(s):

Kun-Chen Lin ◽

Kuan-Hung Chen ◽

Christopher Glenn Wallace ◽

Yi-Ling Chen ◽

Sheung-Fat Ko ◽

...

Keyword(s):

Hyperbaric Oxygen ◽

Infarct Volume ◽

Combined Therapy ◽

Neurological Function ◽

Sprague Dawley ◽

Brain Infarct ◽

Opposite Pattern ◽

Small Vessels ◽

Group 5 ◽

The Brain

Abstract This study tested the hypothesis that combined hyperbaric oxygen (HBO) and melatonin (Mel) was superior to either one for protecting the brain functional and parenchymal integrity from acute ischemic stroke (IS) injury. Adult-male Sprague-Dawley rats were divided into groups 1 (sham-operated control), 2 (IS), 3 (IS + HBO), 4 (IS + Mel), and 5 (IS + HBO-Mel). By day 28 after IS, the brain infarct area (BIA) was lowest in group 1, highest in group 2, significantly higher in groups 3 and 4 than in group 5, but not different between groups 3 and 4. The neurological function at day 7, 14, and 28 exhibited an opposite pattern to BIA among the 5 groups. The protein expressions of inflammatory (IL-1β/IL-6/iNOS/TNF-α/p-NF-κB), apoptotic (cleaved-caspase3/cleaved-PARP/mitochondrial Bax), mitochondrial/DNA-damaged (cytochrome-C/γ-H2AX), oxidative stress (NOX-1/NOX-2), and autophagy (i.e. ratio of CL3B-II/CL3B-I) biomarkers displayed an identical pattern of BIA among 5 groups. Cellular expressions of inflammation (F4/80+/GFAP+) and DNA-damaged biomarker (γ-H2AX+) exhibited an identical pattern, whereas the integrities of myelin sheath/neuron (MPB+/NeuN+), endothelial cell (CD31+/vWF+), and number of small vessels exhibited an opposite pattern of BIA among the 5 groups. Combined HBO-Mel therapy offered an additional benefit in protecting the brain against IS injury.

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Abstract WP263: Protective Role Of Microglial Alpha7 Nicotinic Receptor In Ischemia

Stroke ◽

10.1161/str.44.suppl_1.awp263 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Esther Parada ◽

Javier Egea ◽

Pilar Negredo ◽

Izaskun Buendia ◽

Manuela G Ló

Keyword(s):

Cell Death ◽

Motor Activity ◽

Nicotinic Acetylcholine Receptors ◽

Infarct Volume ◽

Dependent Manner ◽

Walk Test ◽

Sprague Dawley ◽

Experimental Conditions ◽

Α7 Nachr ◽

Photothrombotic Stroke

Background and Purpose: It is well known that activation of α7 nicotinic acetylcholine receptors (nAChR) protects neurons against neurotoxic and neuro-inflammatory stimuli. However, little is known about the importance of this receptor in microglia. This study was planned to evaluate the contribution of microglial α7 nAChRs in controlling inflammation and affording neuroprotection in brain ischemia models. Methods: Organotypic hippocampal cultures (OHCs) were conducted on 8-10 day-old Sprague Dawley rats. Oxygen-glucose deprivation (OGD) was used as an in vitro model of cerebral ischemia. Viability assays with PNU282987 (a selective α7 agonist) were performed 24 hours after the OGD period. Focal ischemia was induced in C57BL/6J mice by photothrombotic stroke; PNU 282987 was administered i.p. 1 h after the ischemia onset. We performed the beam walk test as a measured of motor activity. Infarct volume and beam walk assay were measured 24 hours after the ischemia . Results: In OHCs, 15 minutes of OGD followed by 24 hours of reoxygenation increased cell death (180 ± 2.13, n=6, p<0.001) with respect to the basal slices (100%). Under these experimental conditions, 10μM-PNU282987 administered after the OGD period significantly reduced cell death (110.1 ± 10.41, n=6, p≤0.001). In microglia-depleted slices, we observed that the same period of OGD increased cell death compared to control slices (p<0.05). In addition, the protective effect of PNU282987 was significantly lower (p<0.001). In the phototrombotic stroke model, PNU282987 administered at 1 and 10 mg/kg, reduced the infarct volume in a dose-dependent manner (12.22 ± 0.52, n=8, p<0.05 and 9.28 ± 0.58, n=8, p<0.001, respectively) with respect to the saline animals (15.93 ± 1.2, n=7). In the beam walk test, 10 mg/kg-PNU282987 reduced the studied parameters compared with the saline-mice: freezing time (2.36±0.43 vs 7.29±0.87) time to cross (10.53 ± 0.85 vs 16.95 ± 1.65) and paw slips (5.41 ± 0.77 vs 10.83 ± 0.53). Conclusion: Activation of microglial α7 nAChR contributes to neuroprotection against OGD in OHCs and to reduction of infarct volume and improvement of motor activity in mice subjected to photothrombotic stroke. Taken all together, α7 nicotinic modulation could be a good target for stroke.

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Tbx2 Controls Lung Growth by Direct Repression of the Cell Cycle Inhibitor Genes Cdkn1a and Cdkn1b

Pneumologie ◽

10.1055/s-0034-1376844 ◽

2014 ◽

Vol 68 (06) ◽

Author(s):

T Lüdtke ◽

H Farin ◽

C Rudat ◽

K Schuster-Gossler ◽

M Petry ◽

...

Keyword(s):

Cell Cycle ◽

Lung Growth ◽

Cell Cycle Inhibitor ◽

Inhibitor Genes

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Follicle-Stimulating Hormone Inhibits Adenosine 5′-Monophosphate-Activated Protein Kinase Activation and Promotes Cell Proliferation of Primary Granulosa Cells in Culture through an Akt-Dependent Pathway

Endocrinology ◽

10.1210/en.2008-1032 ◽

2009 ◽

Vol 150 (2) ◽

pp. 929-935 ◽

Cited By ~ 55

Author(s):

Pradeep P. Kayampilly ◽

K. M. J. Menon

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Protein Kinase ◽

Mrna Expression ◽

Granulosa Cell ◽

Granulosa Cells ◽

Ampk Activation ◽

Cyclin D2 ◽

Cell Cycle Inhibitor ◽

Dependent Pathway

FSH, acting through multiple signaling pathways, regulates the proliferation and growth of granulosa cells, which are critical for ovulation. The present study investigated whether AMP-activated protein kinase (AMPK), which controls the energy balance of the cell, plays a role in FSH-mediated increase in granulosa cell proliferation. Cells isolated from immature rat ovaries were grown in serum-free, phenol red free DMEM-F12 and were treated with FSH (50 ng/ml) for 0, 5, and 15 min. Western blot analysis showed a significant reduction in AMPK activation as observed by a reduction of phosphorylation at thr 172 in response to FSH treatment at all time points tested. FSH also reduced AMPK phosphorylation in a dose-dependent manner with maximum inhibition at 100 ng/ml. The chemical activator of AMPK (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, 0.5 mm) increased the cell cycle inhibitor p27 kip expression significantly, whereas the AMPK inhibitor (compound C, 20 μm) and FSH reduced p27kip expression significantly compared with control. FSH treatment resulted in an increase in the phosphorylation of AMPK at ser 485/491 and a reduction in thr 172 phosphorylation. Inhibition of Akt phosphorylation using Akt inhibitor VIII reversed the inhibitory effect of FSH on thr 172 phosphorylation of AMPK, whereas ERK inhibitor U0126 had no effect. These results show that FSH, through an Akt-dependent pathway, phosphorylates AMPK at ser 481/495 and inhibits its activation by reducing thr 172 phosphorylation. AMPK activation by 5-amino-imidazole-4-carboxamide-1-β-d-ribofuranoside treatment resulted in a reduction of cell cycle regulatory protein cyclin D2 mRNA expression, whereas FSH increased the expression by 2-fold. These results suggest that FSH promotes granulosa cell proliferation by increasing cyclin D2 mRNA expression and by reducing p27 kip expression by inhibiting AMPK activation through an Akt-dependent pathway. FSH stimulates granulosa cell proliferation by reducing cell cycle inhibitor p27 kip through AMP kinase inhibition.

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Remote Ischemic Postconditioning vs. Physical Exercise After Stroke: an Alternative Rehabilitation Strategy?

Molecular Neurobiology ◽

10.1007/s12035-021-02329-6 ◽

2021 ◽

Author(s):

Xiaokun Geng ◽

Qingzhu Wang ◽

Hangil Lee ◽

Christian Huber ◽

Melissa Wills ◽

...

Keyword(s):

Physical Exercise ◽

Treadmill Exercise ◽

Infarct Volume ◽

Ischemic Postconditioning ◽

Synaptic Proteins ◽

Neurological Deficits ◽

Sprague Dawley ◽

Neurobehavioral Function ◽

Remote Ischemic Postconditioning ◽

Function Tests

AbstractThere remain debates on neuroprotection and rehabilitation techniques for acute ischemic stroke patients. Therapeutic physical exercise following stroke has shown promise but is challenging to apply clinically. Ischemic conditioning, which has several clinical advantages, is a potential neuroprotective method for stroke rehabilitation that is less understood. In the present study, the rehabilitative properties and mechanisms of physical exercise and remote ischemic postconditioning (RIPostC) after stroke were compared and determined. A total of 248 adult male Sprague-Dawley rats were divided into five groups: (1) sham, (2) stroke, (3) stroke with intense treadmill exercise, (4) stroke with mild treadmill exercise, and (5) stroke with RIPostC. Focal ischemia was evaluated by infarct volume and neurological deficit. Long-term functional outcomes were represented through neurobehavioral function tests: adhesive removal, beam balance, forelimb placing, grid walk, rota-rod, and Morris water maze. To further understand the mechanisms underlying neurorehabilitation and verify the presence thereof, we measured mRNA and protein levels of neuroplasticity factors, synaptic proteins, angiogenesis factors, and regulation molecules, including HIF-1α, BDNF, TrkB, and CREB. The key role of HIF-1α was elucidated by using the inhibitor, YC-1. Both exercise intensities and RIPostC significantly decreased infarct volumes and neurological deficits and outperformed the stroke group in the neurobehavioral function tests. All treatment groups showed significant increases in mRNA and protein expression levels of the target molecules for neurogenesis, synaptogenesis, and angiogenesis, with intermittent further increases in the RIPostC group. HIF-1α inhibition nullified most beneficial effects and indicative molecule expressions, including HIF-1α, BDNF, TrkB, and CREB, in both procedures. RIPostC is equally, or superiorly, effective in inducing neuroprotection and rehabilitation compared to exercise in ischemic rats. HIF-1α likely plays an important role in the efficacy of neuroplasticity conditioning, possibly through HIF-1α/BDNF/TrkB/CREB regulation.

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