scholarly journals Three-dimensional cultured mesenchymal stem cells enhance repair of ischemic stroke through inhibition of microglia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuejiao Li ◽  
Yankai Dong ◽  
Ye Ran ◽  
Yanan Zhang ◽  
Boyao Wu ◽  
...  

Abstract Background We show previously that three-dimensional (3D) spheroid cultured mesenchymal stem cells (MSCs) exhibit reduced cell size thus devoid of lung entrapment following intravenous (IV) infusion. In this study, we determined the therapeutic effect of 3D-cultured MSCs on ischemic stroke and investigated the mechanisms involved. Methods Rats underwent middle cerebral artery occlusion (MCAO) and reperfusion. 1 × 106 of 3D- or 2D-cultured MSCs, which were pre-labeled with GFP, were injected through the tail vain three and seven days after MCAO. Two days after infusion, MSC engraftment into the ischemic brain tissues was assessed by histological analysis for GFP-expressing cells, and infarct volume was determined by MRI. Microglia in the lesion were sorted and subjected to gene expressional analysis by RNA-seq. Results We found that infusion of 3D-cultured MSCs significantly reduced the infarct volume of the brain with increased engraftment of the cells into the ischemic tissue, compared to 2D-cultured MSCs. Accordingly, in the brain lesion of 3D MSC-treated animals, there were significantly reduced numbers of amoeboid microglia and decreased levels of proinflammatory cytokines, indicating attenuated activation of the microglia. RNA-seq of microglia derived from the lesions suggested that 3D-cultured MSCs decreased the response of microglia to the ischemic insult. Interestingly, we observed a decreased expression of mincle, a damage-associated molecular patterns (DAMPs) receptor, which induces the production of proinflammatory cytokines, suggestive of a potential mechanism in 3D MSC-mediated enhanced repair to ischemic stroke. Conclusions Our data indicate that 3D-cultured MSCs exhibit enhanced repair to ischemic stroke, probably through a suppression to ischemia-induced microglial activation.

2021 ◽  
Author(s):  
Qi Zhang ◽  
Chang Liu ◽  
Rubing Shi ◽  
Huimin Shan ◽  
Lidong Deng ◽  
...  

Abstract Background Astrocytes play an essential role in the modulation of blood-brain barrier function. Neurological diseases induce astrocytes to transform into a neurotoxic A1 phenotype, thus exacerbating brain injury. However, the effect of A1 astrocyte on the function of BBB after stroke is unknown. Method: Adult male ICR mice (n = 78) were subjected to 90-minute transient middle cerebral artery occlusion. Immunohistochemical staining of A1 (C3d) and A2 (S100A10) was performed to characterize phenotypic changes of astrocytes overtime after stroke. Glucagon-like peptide-1 receptor agonist semaglutide was intraperitoneally injected into the mice to inhibit A1 astrocyte. Infarct volume, atrophy volume, neurobehavioral outcomes, and BBB permeability were examined. RNA-seq was adopted to explore the potential targets and signaling pathways of A1 astrocytes induced BBB dysfunction. Results Astrocytes assumed the A2 phenotype at the early stage of ischemic stroke but gradually transformed to the A1 phenotype. Semaglutide treatment reduced M1 microglia polarization and A1 astrocytes conversion after ischemic stroke (p < 0.05). Ischemia induced brain infarct volume, atrophy volume and neuroinflammation were reduced in the semaglutide treated mice. Neurobehavioral outcomes were improved compared to the control mice (p < 0.05). Further study demonstrated that semaglutide treatment reduced the gap formation of tight junction proteins ZO-1, claudin-5 and occludin, as well as IgG leakage following three days of ischemic stroke (p < 0.05). In vitro experiments revealed that A1 astrocyte-conditioned medium disrupted BBB integrity. RNA-seq further showed that A1 astrocytes were enriched in inflammatory factors and chemokines, as well as significantly modulating TNF and chemokine signaling pathways, which are closely related to barrier damage. Conclusion We concluded that astrocytes undergo a conversion from A2 phenotype to A1 phenotype overtime after ischemic stroke. A1 astrocytes aggravated BBB disruption, suggesting that block of A1 astrocytes conversion provides a novel strategy for the treatment of ischemic stroke.


2021 ◽  
Vol 20 (2) ◽  
pp. 77-86
Author(s):  
V. V. Andrianov ◽  
V. A. Kulchitsky ◽  
G. G. Yafarova ◽  
Yu. P. Tokalchik ◽  
A. S. Zamaro ◽  
...  

Introduction. With a decrease in the oxygen content in the inhaled air, violations of the cerebral blood flow, brain ischemia occurs, which can end in an ischemic stroke. Aim. Comparative analysis of the intensity of nitric oxide (NO) production and the copper content in the olfactory bulb tissues of the brain of male Wistar rats after modeling an ischemic stroke. Materials and methods. Modeling of ischemic stroke by ligation at the bifurcation level of both common carotid arteries and measuring the content of NO and copper by EPR spectroscopy. Results. The relative changes in the number of NO-containing complexes and the copper content were estimated from the integrated signal intensity of the complexes (DETC)2-Fe2+-NO and (DETC)2- Cu. A significant decrease by 47 % after 1 and 57 % after 2 days, respectively, in the NO content in the olfactory bulb of the rat brain was found after the ischemia modeling. The level of NO production in rats that underwent ischemia simulation with simultaneous intranasal administration of mesenchymal stem cells (MSCs) was also reduced by 51 % after 1 and 70 % after 2 days, respectively, after ischemia modeling. There was no significant difference in the NO content in the rats after ischemia modeling with simultaneous intranasal administration of MSCs compared to the ischemic rats. The copper content, which corresponds to the level of superoxide dismutase 1 and 3, in the rat’s olfactory bulb tended to increase after ischemia modeling and it persisted for two days of observation (an increase of 50 % in both cases). Intranasal administration of MSCs was accompanied by a significant increase in the Cu content (by 89 %) 1 day after the ischemia modeling, and 2 days later – by a decrease in its content by 36 % (compared to the control). In the control animals that were not subjected to surgical operations, no changes in the content of NO or copper were observed. Conclusion. The experiments showed a 2-fold decrease in the NO content in the olfactory bulb of the rat brain 1 and 2 days after the ischemia modeling, and demonstrated that the intranasal administration of MSCs did not affect the intensity of NO production on the 1st and 2nd days after the brain ischemia modeling, but was accompanied by an increase in the antioxidant protection of the nervous tissue one day after ischemia.


2020 ◽  
Vol 76 (12) ◽  
pp. 10090-10121
Author(s):  
Yung-Kuan Chan ◽  
Chun-Fu Hong ◽  
Meng-Hsiun Tsai ◽  
Ya-Lan Chang ◽  
Ping-Hsuan Sun

Abstract Stroke is one of the leading causes of death as well as results in a massive economic burden for society. Stroke is a cerebrovascular disease mainly divided into two types: ischemic stroke and hemorrhagic stroke, which, respectively, refer to the partial blockage and bleeding inside brain blood vessels. Both stroke types lead to nutrient and oxygen deprivation in the brain, which ultimately cause brain damage or death. This study focuses on ischemic stroke in rats with middle cerebral artery occlusion (MCAO) as experimental subjects, and the volumes of infarct and atrophy are calculated based on the brain slice images of rat brains stained with 2,3,5-triphenyl tetrazolium chloride. In this study, a stroke rat brain infarct and atrophy volumes computation system (SRBIAVC system) is developed to segment the infarcts and atrophies from the rat brain slice images. Based on the segmentation results, the infarct and atrophy volumes of a rat brain can be computed. In this study, 168 images of brain slices cut from 28 rat brains with MCAO are used as the test samples. The experimental results show that the segmentation results obtained by the SRBIAVC system are close to those obtained by experts.


2021 ◽  
Author(s):  
Jun Yan ◽  
Te Liu ◽  
Jun Zhang ◽  
Bo Shi ◽  
Fuqiang Zhang ◽  
...  

Abstract Mesenchymal stem cells are a potential therapeutic candidate for cerebral infarction due to their anti-inflammatory proprieties. However, ensuring the engraftment of sufficient cells into the affected brain area remains a challenge. Herein, magnetic targeting techniques were used for the noninvasive transplantation of a large number of cells noninvasively. Mice subjected to permanent middle cerebral artery occlusion surgery were administered mesenchymal stem cells labeled or not with iron oxide@polydopamine nanoparticles by tail vein injection. Iron oxide@polydopamine particles were characterized by transmission electron microscopy, and labeled mesenchymal stem cells were characterized by flow cytometry and their differentiation potential was assessed in vitro . Following the systemic injection of iron oxide@polydopamine-labeled mesenchymal stem cells into permanent transient middle cerebral artery occlusion-induced mice, magnetic navigation increased the MSCs localization to the brain lesion site and reduced the lesion volume. Treatment with iron oxide@polydopamine-labeled mesenchymal stem cells also significantly inhibited M1 microglia polarization and increased M2 microglia cell infiltration. Furthermore, western blotting and immunohistochemical analysis demonstrated that microtubule-associated protein 2 and NeuN levels were upregulated the brain tissue of mice treated with iron oxide@polydopamine-labeled mesenchymal stem cells. Thus, iron oxide@polydopamine-labeled mesenchymal stem cells attenuated brain injury and protected neurons by preventing pro-inflammatory microglia activation. Overall, the proposed iron oxide@polydopamine-labeled mesenchymal stem cells approach may overcome the major drawback of the conventional MSCs therapy for the treatment of cerebral infarction.


2018 ◽  
Vol 46 (5) ◽  
pp. 1951-1970 ◽  
Author(s):  
XiaoBo Li ◽  
Min Huang ◽  
RenChao Zhao ◽  
ChunSong Zhao ◽  
Yao Liu ◽  
...  

Background/Aims: Neurotrophic effects and immunosuppression are the main therapeutic mechanisms of mesenchymal stem cells (MSCs) in stroke treatment. Neurotrophins are produced by graft cells, host neurons, astrocytes, and even microglia/macrophages. Meanwhile, MSCs can increase inflammation if they are not sufficiently induced by pro-inflammatory cytokines. We examined whether intravenously transplanted bone marrow MSCs (BM-MSCs) increase inflammation in distal middle cerebral artery occlusion (dMCAO) rats, how long the increased inflammation effect persists for, and what the final therapeutic outcomes will be. We also tested the neurotrophic role of BM-MSCs and attempted to identify the neurotrophin-producing cells. Methods: At 1 h after dMCAO was performed on Sprague-Dawley rats, allogeneic BM-MSCs were transplanted intravenously. The infarct volume was examined by Tetrazolium Red staining at 2 days (day 2), and the behavioral tests (cylinder test and grid walking test) were performed at 2, 4 (day 4) and 7 days (day 7) after transplantation. The concentrations of inflammation related cytokines and neurotrophins in the ischemic cortex, ipsilateral striatum, and serum, were measured using ELISA at days 2-7. The cell source of neurotrophins was observed by immunohistochemistry. Results: The transplanted cells were mainly found in the infarct border zone (IBZ) of the brain. Infarct volume was reduced and behavioral outcomes were improved at 2 days after ischemia. In the striatum and circulation, BM-MSC transplantation increased inflammation at day 2 and decreased it at day 7. At days 2-7, insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF) concentrations in the ischemic core of the cortex were significantly higher in the BM-MSC group than in the ischemia vehicle group. IGF-1 and BDNF were derived mainly from host microglia/macrophages in the ischemic core, and transplanted cells in the IBZ. At day 2, BM-MSC transplantation significantly increased the number of IGF-1+CD68+ and BDNF+Iba-1+ double positive cells in the ischemic core cortex. Conclusions: Although increased inflammation, BM-MSCs were still beneficial to dMCAO recovery at day 2. The immunopromoting effect of MSCs was transient and shifted to an immunosuppressive action at day 7. The neurotrophic factors IGF-1 and BDNF, which were mainly derived from transplanted BM-MSCs and host microglia/macrophages, contributed to the therapeutic effects from day 2 to day 7.


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