GNA14 and GNAQ somatic mutations cause spinal and intracranial extra-axial cavernous hemangiomas.

Extra-axial cavernous hemangiomas (ECHs) are complex vascular lesions mainly found in the spine and cavernous sinus. Their removal poses significant risk due to their vascularity and diffuse nature, and their genetic underpinnings remain incompletely understood. Our approach involved genetic analyses on 31 tissue samples of ECHs employing whole-exome sequencing and targeted deep sequencing. We explored downstream signaling pathways, gene expression changes, and resultant phenotypic shifts induced by these mutations, both in vitro and in vivo. In our cohort, 77.4% of samples had somatic missense variants in GNA14, GNAQ, or GJA4. Transcriptomic analysis highlighted significant pathway upregulation, with the GNAQ c.626A>G (p.Gln209Arg) mutation elevating PI3K-AKT-mTOR and angiogenesis-related pathways, while GNA14 c.614A>T (p.Gln205Leu) mutation led to MAPK and angiogenesis-related pathway upregulation. Using a mouse xenograft model, we observed enlarged vessels from these mutations. Additionally, we initiated rapamycin treatment in a 14-year-old individual harboring the GNAQ c.626A>G (p.Gln209Arg) variant, resulting in gradual regression of cutaneous cavernous hemangiomas and improved motor strength, with minimal side effects. Understanding these mutations and their pathways provides a foundation for developing therapies for ECHs resistant to current therapies. Indeed, the administration of rapamycin in an individual within this study highlights the promise of targeted treatments in treating these complex lesions.

Treatment of Syringomyelia Characterized by Focal Dilatation of the Central Canal Using Mesenchymal Stem Cells and Neural Stem Cells.

BACKGROUND: Syringomyelia is a progressive chronic disease that leads to nerve pain, sensory dissociation, and dyskinesia. Symptoms often do not improve after surgery. Stem cells have been widely explored for the treatment of nervous system diseases due to their immunoregulatory and neural replacement abilities. METHODS: In this study, we used a rat model of syringomyelia characterized by focal dilatation of the central canal to explore an effective transplantation scheme and evaluate the effect of mesenchymal stem cells and induced neural stem cells for the treatment of syringomyelia. RESULTS: The results showed that cell transplantation could not only promote syrinx shrinkage but also stimulate the proliferation of ependymal cells, and the effect of this result was related to the transplantation location. These reactions appeared only when the cells were transplanted into the cavity. Additionally, we discovered that cell transplantation transformed activated microglia into the M2 phenotype. IGF1-expressing M2 microglia may play a significant role in the repair of nerve pain. CONCLUSION: Cell transplantation can promote cavity shrinkage and regulate the local inflammatory environment. Moreover, the proliferation of ependymal cells may indicate the activation of endogenous stem cells, which is important for the regeneration and repair of spinal cord injury.

Corrigendum: Proteomic profiling reveals the potential mechanisms and regulatory targets of sirtuin 4 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's mouse model.

[This corrects the article DOI: 10.3389/fnins.2022.1035444.].

Self-Powered, Implantable, and Wirelessly Controlled NO Generation System for Intracranial Neuroglioma Therapy.

Gas therapy is an emerging technology for improving cancer therapy with high efficiency and low side effects. However, due to the existence of the gatekeeper of the blood-brain barrier (BBB) and the limited availability of current drug delivery systems, there still have been no reports on gas therapy for intracranial neuroglioma. Herein, an integrated, self-powered, and wirelessly controlled gas-therapy system is reported, which is composed of a self-powered triboelectric nanogenerator (TENG) and an implantable nitric oxide (NO) releasing device for intracranial neuroglioma therapy. In the system, the patient self-driven TENG converts the mechanical energy of body movements into electricity as a sustainable and self-controlled power source. When delivering energy to light a light-emitting diode in the implantable NO releasing device via wireless control, the encapsulated NO donor s-nitrosoglutathione (GSNO) can generate NO gas to locally kill the glioma cells. The efficacy of the proof-of-concept system in subcutaneous 4T1 breast cancer model in mice and intracranial glioblastoma multiforme in rats is verified. This self-powered gas-therapy system has great potential to be an effective adjuvant treatment modality to inhibit tumor growth, relapse, and invasion via teletherapy.

Induced neural stem cells from Macaca fascicularis show potential of dopaminergic neuron specification and efficacy in a mouse Parkinson's disease model.

Induced neural stem cells (iNSCs) can be reprogrammed from somatic cells and have shown potentials in treatment of various neurological diseases/disorders. Obtaining iNSCs of nonhuman primates serves as an important bridge for clinical translation using iNSCs. In the current study, cynomolgus (Macaca fascicularis) bone marrow mesenchymal stromal cells (MSCs) were reprogrammed into iNSCs by transduction of non-integrative Sendai virus encoding transgenes OCT4, SOX2, KLF4 and C-MYC. The obtained iNSCs showed characteristics of normal neural stem cells (NSCs) and could differentiate into neurons, astrocytes and oligodendrocytes. Furthermore, iNSCs could give rise to dopaminergic neural cells in vitro, which showed safety and efficacy after transplantation into the striatum of an immunodeficient mouse Parkinson's disease (PD) model.

Prognostic Biomarker KIF18A and Its Correlations With Immune Infiltrates and Mitosis in Glioma.

Background: Glioma is globally recognised as one of the most frequently occurring primary malignant brain tumours, making the identification of glioma biomarkers critically significant. The protein KIF18A (Kinesin Family Member 18A) is a member of the kinesin superfamily of microtubule-associated molecular motors and has been shown to participate in cell cycle and mitotic metaphase and anaphase. This is the first investigation into the expression of KIF18A and its prognostic value, potential biological functions, and effects on the immune system and mitosis in glioma patients. Methods: Gene expression and clinicopathological analysis, enrichment analysis, and immune infiltration analysis were based on data obtained from The Cancer Genome Atlas (TCGA), with additional bioinformatics analyses performed. Statistical analysis was conducted in R software. Clinical samples were used to evaluate the expression of KIF18A via immunohistochemical staining. In addition, the expression level of KIF18A was validated on U87 cell line. Results: Our results highlighted that KIF18A plays a key role as an independent prognostic factor in patients with glioma. KIF18A was highly expressed in glioma tissues, and KIF18A expression was associated with age, World Health Organization grade, isocitrate dehydrogenase (IDH) status, 1p/19q codeletion, primary therapy outcome, and overall survival (OS). Enrichment analysis revealed that KIF18A is closely correlated with the cell cycle and mitosis. Single sample gene set enrichment analysis (ssGSEA) analysis revealed that KIF18A expression was related to the immune microenvironment. The increased expression of KIF18A in glioma was verified in clinical samples and U87 cell line. Conclusion: The identification of KIF18A as a new biomarker for glioma could help elucidate how changes in the glioma cell and immune microenvironment promote glioma malignancy. With further analysis, KIF18A may serve as an independent prognostic indicator for human glioma.

Identification of CD101 in Glioma: A Novel Prognostic Indicator Expressed on M2 Macrophages.

Glioma represents the most common primary intracranial malignancy worldwide, with low overall survival rates and limited therapeutic options. The protein CD101, mainly expressed on several immune cells, has been demonstrated to exert potent effects on blunting T cell immune responses across infectious and autoimmunity diseases. Nevertheless, the prognostic value of CD101 expression and its role in the immune microenvironment of various malignancies currently remains elusive. Herein, by adopting bioinformatics methodology, we comprehensively illustrated the potential function and predictive value of CD101 in stratifying clinical prognosis among patients with glioma, for which a high CD101 level predicted an unfavorable clinical outcome in glioma patients. Results from enrichment analyses manifested that CD101 predominantly expressed on the tumor-associated macrophages and was significantly associated with the immune regulatory processes, as evidenced by its positive correlation with immune-related genes and the putative infiltration of immune cells. Evidence provided by in-situ multicolor immunofluorescence staining further validated our findings at the protein level. Taken together, CD101 may serve as a novel biomarker in predicting clinical prognosis and immune status for glioma patients.

Proteomic profiling reveals the potential mechanisms and regulatory targets of sirtuin 4 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's mouse model.

Introduction: Parkinson's disease (PD), as a common neurodegenerative disease, currently has no effective therapeutic approaches to delay or stop its progression. There is an urgent need to further define its pathogenesis and develop new therapeutic targets. An increasing number of studies have shown that members of the sirtuin (SIRT) family are differentially involved in neurodegenerative diseases, indicating their potential to serve as targets in therapeutic strategies. Mitochondrial SIRT4 possesses multiple enzymatic activities, such as deacetylase, ADP ribosyltransferase, lipoamidase, and deacylase activities, and exhibits different enzymatic activities and target substrates in different tissues and cells; thus, mitochondrial SIRT4 plays an integral role in regulating metabolism. However, the role and mechanism of SIRT4 in PD are not fully understood. This study aimed to investigate the potential mechanism and possible regulatory targets of SIRT4 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice. Methods: The expression of the SIRT4 protein in the MPTP-induced PD mouse mice or key familial Parkinson disease protein 7 knockout (DJ-1 KO) rat was compared against the control group by western blot assay. Afterwards, quantitative proteomics and bioinformatics analyses were performed to identify altered proteins in the vitro model and reveal the possible functional role of SIRT4. The most promising molecular target of SIRT4 were screened and validated by viral transfection, western blot assay and reverse transcription quantitative PCR (RT-qPCR) assays. Results: The expression of the SIRT4 protein was found to be altered both in the MPTP-induced PD mouse mice and DJ-1KO rats. Following the viral transfection of SIRT4, a quantitative proteomics analysis identified 5,094 altered proteins in the vitro model, including 213 significantly upregulated proteins and 222 significantly downregulated proteins. The results from bioinformatics analyses indicated that SIRT4 mainly affected the ribosomal pathway, propionate metabolism pathway, peroxisome proliferator-activated receptor (PPAR) signaling pathway and peroxisome pathway in cells, and we screened 25 potential molecular targets. Finally, only fatty acid binding protein 4 (FABP4) in the PPAR signaling pathway was regulated by SIRT4 among the 25 molecules. Importantly, the alterations in FABP4 and PPARγ were verified in the MPTP-induced PD mouse model. Discussion: Our results indicated that FABP4 in the PPAR signaling pathway is the most promising molecular target of SIRT4 in an MPTP-induced mouse model and revealed the possible functional role of SIRT4. This study provides a reference for future drug development and mechanism research with SIRT4 as a target or biomarker.

Astrocytes constitute the major TNF-α-producing cell population in the infarct cortex in dMCAO rats receiving intravenous MSC infusion.

Recent studies report that inhibiting TNF-α might be a novel therapeutic strategy for managing brain ischemia. Our previous study reported that mesenchymal stem cell (MSC) transplantation could suppress TNF-α level in both serum and brain. However, the cell type(s) that contribute to the production of TNF-α during ischemia following MSC transplantation has not been well studied. In the present study, we found by fluorescent immunohistochemistry, that 7.95 ± 6.17% of TNF-α+ cells co-expressed Iba-1 in the infarct area of dMCAO rats, a majority of which were found to be CD68+ (activated microglia), suggesting that resident microglial population were not the major source of TNF-α expression. 68.49 ± 5.12% of the TNF-α+ cells in the infarct area could be labeled by GFAP, a specific marker for astrocytes, indicating that resident GFAP+ astrocytes might be the major source of TNF-α expression in the infarct area. In addition to the infarct area, the GFAP+/TNF-α+ double-positive astrocytes accounted for 73.68 ± 7.48% of the TNF-α+ cells in striatum and corpus callosum. The infiltrating cells, including monocytes and lymphocytes, were not the main source of TNF-α either. In response to MSC transplantation, the total TNF-α+ cells as well as the percentage of TNF-α-expressing astrocytes were significantly reduced in the infarct area, suggesting that MSC transplantation could suppress the expression of TNF-α by astrocytes. Taken together, the results demonstrated that resident astrocytes, but not microglia, were the major source of TNF-α expression and could be suppressed by MSC infusion.

Bone marrow mesenchymal stem cell transplantation downregulates plasma level and the microglia expression of transforming growth factor ß1 in the acute phase of cerebral cortex ischemia.

BACKGROUND: Both bone marrow mesenchymal stem cell (BM-MSC) and transforming growth factor-ß1 (TGF-ß1) have a strong anti-inflammatory capacity in stroke. But their relationship has not been well addressed. In this study, we investigated how intravenous BM-MSC transplantation in rats effected the expression of TGF-ß1 48 h post cerebral ischemia, and we analyzed the main cells that produce TGF-ß1. METHODS: We used a distal middle cerebral artery occlusion (dMCAO) model in twenty Sprague-Dawley (SD) rats. The rats were randomly divided into two groups: the ischemic control group and the postischemic BM-MSC transplantation group. One hour after the dMCAO model was established, the rats were injected in the tail vein with either 1 ml saline or 1 × 106 BM-MSCs suspended in 1 ml saline. ELISAs were used to detect TGF-ß1 content in the brain infarct core area, striatum and the plasma at 48 h after cerebral infarction. Immunofluorescent staining of brain tissue sections for TGF-ß1, Iba-1, CD68 and NeuN was performed to determine the number and the proportion of double stained cells and to detect possible TGF-ß1 producing cells in the brain tissue. RESULTS: Forty-eight hours after ischemia, the TGF-ß1 content in the infarcted area of the BM-MSC transplantation group (23.94 ± 4.48 pg/ml) was significantly lower than it was in the ischemic control group (34.18 ± 4.32 pg/ml) (F = 13.534, P = 0.006). The TGF-ß1 content in the rat plasma in the BM-MSC transplantation group (75.91 ± 12.53 pg/ml) was significantly lower than it was in the ischemic control group (131.18 ± 16.07 pg/ml) (F = 36.779, P = 0.0002), suggesting that after transplantation of BM-MSCs, TGF-ß1 levels in the plasma decreased, but there was no significant change in the striatum area. Immunofluorescence staining showed that the total number of nucleated cells (1037.67 ± 222.16 cells/mm2) in the infarcted area after transplantation was significantly higher than that in the ischemic control group (391.67 ± 69.50 cells/mm2) (F = 92.421, P < 0.01); the number of TGF-ß1+ cells after transplantation (35.00 ± 13.66 cells/mm2) was significantly reduced in comparison to that in the ischemic control group (72.33 ± 32.08 cells/mm2) (F = 37.680, P < 0.01). The number of TGF-ß1+/Iba-1+ microglia cells in the transplantation group (3.67 ± 3.17 cells/mm2) was significantly reduced in comparison to that of the ischemic control group (13.67 ± 5.52 cells/mm2) (F = 29.641, P < 0.01). The proportion of TGF-ß1+/Iba-1+ microglia cells out of all Iba-1+ microglia cells after transplantation (4.38 ± 3.18%) was significantly decreased compared with that in the ischemic control group (12.81 ± 4.86%) (F = 28.125, P < 0.01). CONCLUSIONS: Iba-1+ microglia is one of the main cell types that express TGF-ß1. Intravenous transplantation of BM-MSCs does not cooperate with TGF-ß1+ cells in immune-regulation, but reduces the TGF-ß1 content in the infarcted area and in the plasma at 48 h after cerebral infarction.

Peripheral Circulation and Astrocytes Contribute to the MSC-Mediated Increase in IGF-1 Levels in the Infarct Cortex in a dMCAO Rat Model.

MATERIALS AND METHODS: Ischemic brain injury was induced by dMCAO in Sprague-Dawley rats. The transplantation group received MSC infusion 1 h after dMCAO. Expression of IGF-1 in GFAP+ astrocytes, Iba-1+ microglia/macrophages, CD3+ lymphocytes, Ly6C+ monocytes/macrophages, and neutrophil elastase (NE)+ neutrophils was examined to determine the contribution of these cells to the increase of IGF-1. ELISA was performed to examine IGF-1 levels in blood plasma at days 2, 4, and 7 after ischemia onset. RESULTS: In total, only 5-6% of Iba-1+ microglia were colabeled with IGF-1 in the infarct cortex, corpus callosum, and striatum at day 2 post-dMCAO. MSC transplantation did not lead to a higher proportion of Iba-1+ cells that coexpressed IGF-1. In the infarct cortex, all Iba-1+/IGF-1+ double-positive cells were also positive for CD68. In the infarct, corpus callosum, and striatum, the majority (50-80%) of GFAP+ cells were colabeled with ramified IGF-1 signals. The number of GFAP+/IGF-1+ cells was further increased following MSC treatment. In the infarct cortex, approximately 15% of IGF-1+ cells were double-positive for CD3. MSC treatment reduced the number of infiltrated CD3+/IGF-1+ cells by 70%. In the infarct, few Ly6C+ monocytes/macrophages or NE+ neutrophils expressed IGF-1, and MSC treatment did not induce a higher percentage of these cells that coexpressed IGF-1. The IGF-1 level in peripheral blood plasma was significantly higher in the MSC group than in the ischemia control group. CONCLUSION: The MSC-mediated increase in IGF-1 levels in the infarct cortex mainly derives from two sources, astrocytes in brain and blood plasma in periphery. Manipulating the IGF-1 level in the peripheral circulation may lead to a higher level of IGF-1 in brain, which could be conducive to recovery at the early stage of dMCAO.

Plasma RANTES level is correlated with cardio-cerebral atherosclerosis burden in patients with ischemic cerebrovascular disease.

BACKGROUND: Regulated upon activation, normal T-cell expressed, and secreted (RANTES) is a chemokine actively involved in the initiation and progression of atherosclerosis (AS), which is the major cause of ischemic cerebrovascular disease (ICVD). This study aimed to determine the associations between circulating RANTES level and overall AS conditions of cardiac and cerebral vessel beds in patients with ICVD. METHODS: Patients with ICVD admitted to the department of neurology of Xuanwu Hospital from April 1, 2019 to June 30, 2019 were prospectively enrolled in the study. Plasma RANTES level was measured by enzyme-linked immunosorbent assay to represent the circulating RANTES level. The integrated AS burden of the cervicocephalic and coronary arteries was examined using computed tomography angiography and reflected by "cardio-cerebral AS burden (CCAB)" as a continuous variable. Then, the relationship of plasma RANTES level and CCAB in patients with ICVD was analyzed by correlation analyses and general linear models. RESULTS: A total of 40 patients with ICVD were included in the study. There was a significant positive correlation between CCAB and plasma RANTES level in ICVD (r = 0.786, P < 0.001), independent of age, sex, acute or chronic phase of ICVD, and mono or dual antiplatelet therapy (adjusted B for ln RANTES, 12.063; 95% confidence interval, 7.572-16.533). The association of plasma RANTES level with AS conditions (burden, severity, and extent) in single cardiac or cerebral vessel bed was similar to that with CCAB, but the correlation coefficient for CCAB was higher (increment ranged from 0.126 to 0.397). CONCLUSIONS: Plasma RANTES level was an independent indicator for the integrated AS burden of the cervicocephalic and coronary arteries in ICVD. Comprehensive evaluation of AS conditions using the novel continuous index CCAB might be important in revealing the systematic relationship between circulating RANTES and AS in patients with ICVD.

The Effect of Human Umbilical Cord Mesenchymal Stromal Cells in Protection of Dopaminergic Neurons from Apoptosis by Reducing Oxidative Stress in the Early Stage of a 6-OHDA-Induced Parkinson's Disease Model.

Oxidative stress is an important cause of dopaminergic (DA) neuron apoptosis in Parkinson's disease (PD). Mesenchymal stromal cells (MSCs) possess antioxidative features. In this study, we investigated whether MSCs could reduce oxidative stress and protect DA neurons from apoptosis by intravenous (I.V.) injection in the early stage of a 6-hydroxydopamine (6-OHDA)-induced PD model. MSCs were injected into the tail vein of mice, and behavioral tests, immunofluorescence staining, western blot, and oxidative stress levels were assessed at different time points. After 6-OHDA exposure, DA neuron apoptosis was detected, together with severe oxidative stress in brain and periphery. Compared with the non-transplanted sham controls, motor function in the 6-OHDA-lesioned group after I.V. injection of MSCs was significantly improved, and the levels of DA neuron apoptosis and oxidative stress decreased. The results demonstrate that MSCs can rescue DA neurons from ongoing apoptosis by reducing oxidative stress, and provide insights on developing new therapeutic strategies to offset the degenerative process of PD.

Glioblastoma extracellular vesicles induce the tumour-promoting transformation of neural stem cells.

Recurrent glioblastomas are frequently found near subventricular zone (SVZ) areas of the brain where neural stem cells (NSCs) reside, and glioblastoma-derived extracellular vesicles (EVs) are reported to play important roles in tumour micro-environment, but the details are not clear. Here, we investigated the possibility that NSCs are involved in glioblastoma relapse mediated by glioblastoma-derived EVs. We studied changes to NSCs by adding glioblastoma-derived EVs into a culture system of NSCs, and found that NSCs differentiated into a type of tumour-promoting cell. These transformed cells had distinguished proliferation activity, a high migration rate, and clone-forming ability revealed by CCK-8, wound healing and soft agar clone formation assays, respectively. In vivo assays indicated that these cells could accelerate tumour formation by Ln229 cells in nude mice. Moreover, to explore the mechanisms underlying NSC transformation, single cell transcriptome sequencing was performed; our results suggest that several key genes such as S100B, CXCL14, EFEMP1, SCRG1, GLIPR1, HMGA1 and CD44 and dysregulated signalling may be important for the transformation of NSCs. It is also indicated that NSCs may be involved in glioblastoma recurrence through EV release by glioblastoma in this work. This could help to illuminate the mechanism of glioblastoma relapse, which occurs in a brief period after surgical excision, and contribute to finding new ways to treat this disease.

Aging, rather than Parkinson's disease, affects the responsiveness of PBMCs to the immunosuppression of bone marrow mesenchymal stem cells.

Whether aging or Parkinson's disease (PD) affects the responses of peripheral blood mononuclear cells (PBMCs) to immunosuppression by bone marrow­derived mesenchymal stem cell (BM­MSCs) and which cytokines are more effective in inducing BM­MSCs to be immunosuppressive remains to be elucidated. PBMCs were isolated from healthy young (age 26­35), healthy middle­aged (age 56­60) and middle­aged PD­affected individuals. All the recruits were male. The mitogen­stimulated PBMCs and proinflammatory cytokine­pretreated BM­MSCs were co­cultured. The PBMC proliferation was measured using Cell Counting Kit­8, while the cytokine secretion was assayed by cytometric bead array technology. The immunosuppressive ability of BM­MSCs was confirmed in young healthy, middle­aged healthy and middle­aged PD­affected individuals. Among the three groups, the PBMC proliferation and cytokine secretion of the young healthy group were suppressed more significantly compared with those of the middle­aged healthy and middle­aged PD­affected group. No significant differences were identified in the PBMC proliferation and cytokine secretion between the patients with PD and the middle­aged healthy subjects. Interferon (IFN)­Î³ synergized with tumor necrosis factor (TNF)­α, interleukin (IL)­1α or IL­1ß was more effective than either one alone, and the combinations of IFN­Î³ + IL­1α and IFN­Î³ + IL­1ß were more effective than IFN­Î³ + TNF­α in inducing BM­MSCs to inhibit PBMC proliferation. The results of the present study suggested that aging, rather than PD, affects the response of PBMCs toward the suppression of BM­MSC, at least in middle­aged males. Patients with PD aged 56­60 remain eligible for anti­inflammatory BM­MSC­based therapy. Treatment of BM­MSCs with IFN­Î³ + IL­1α or IFN­Î³ + IL­1ß prior to transplantation may result in improved immunosuppressive effects.

Intravenous Transplantation of Mesenchymal Stem Cells Reduces the Number of Infiltrated Ly6C+ Cells but Enhances the Proportions Positive for BDNF, TNF-1α, and IL-1ß in the Infarct Cortices of dMCAO Rats.

The resident microglial and infiltrating cells from peripheral circulation are involved in the pathological processes of ischemia stroke and may be regulated by mesenchymal stem/stromal cell (MSC) transplantation. The present study is aimed at differentiating the neurotrophic and inflammatory roles played by microglial vs. infiltrating circulation-derived cells in the acute phase in rat ischemic brains and explore the influences of intravenously infused allogeneic MSCs. The ischemic brain injury was induced by distal middle cerebral artery occlusion (dMCAO) in SD rats, with or without MSC infusion in the same day following dMCAO. Circulation-derived infiltrating cells in the brain were identified by Ly6C, a majority of which were monocytes/macrophages. Without MSC transplantation, among the infiltrated Ly6C+ cells, some were positive for BDNF, IL-1ß, or TNF-α. Following MSC infusion, the overall number of Ly6C+ infiltrated cells was reduced by 50%. In contrast, the proportions of infiltrated Ly6C+ cells coexpressing BDNF, IL-1ß, or TNF-α were significantly enhanced. Interestingly, Ly6C+ cells in the infarct area could produce either neurotrophic factor BDNF or inflammatory cytokines (IL-1ß or TNF-α), but not both. This suggests that the Ly6C+ cells may constitute heterogeneous populations which react differentially to the microenvironments in the infarct area. The changes in cellular composition in the infarct area may have contributed to the beneficial effect of MSC transplantation.

Intravenously Delivered Allogeneic Mesenchymal Stem Cells Bidirectionally Regulate Inflammation and Induce Neurotrophic Effects in Distal Middle Cerebral Artery Occlusion Rats Within the First 7 Days After Stroke.

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.

EphB4 Regulates Self-Renewal, Proliferation and Neuronal Differentiation of Human Embryonic Neural Stem Cells in Vitro.

BACKGROUND/AIMS: EphB4 belongs to the largest family of Eph receptor tyrosine kinases. It contributes to a variety of pathological progresses of cancer malignancy. However, little is known about its role in neural stem cells (NSCs). This study examined whether EphB4 is required for proliferation and differentiation of human embryonic neural stem cells (hNSCs) in vitro. METHODS: We up- and down-regulated EphB4 expression in hNSCs using lentiviral over-expression and shRNA knockdown constructs and then investigated the influence of EphB4 on the properties of hNSCs. RESULTS: Our results show that shRNA-mediated EphB4 reduction profoundly impaired hNSCs self-renewal and proliferation. Furthermore, detection of differentiation revealed that knockdown of EphB4 inhibited hNSCs differentiation towards a neuronal lineage and promoted hNSCs differentiation to glial cells. In contrast, EphB4 overexpression promoted hNSCs self-renewal and proliferation, further induced hNSCs differentiation towards a neuronal lineage and inhibited hNSCs differentiation to glial cells. Moreover, we found that EphB4 regulates cell proliferation mediated by the Abl-CyclinD1 pathway. CONCLUSION: These studies provide strong evidence that fine tuning of EphB4 expression is crucial for the proliferation and neuronal differentiation of hNSCs, suggesting that EphB4 might be an interesting target for overcoming some of the therapeutic limitations of neuronal loss in brain diseases.

Comparsion between Intravenous Delivered Human Fetal Bone Marrow Mesenchymal Stromal Cells and Mononuclear Cells in the Treatment of Rat Cerebral Infarct.

Objective To compare the effecacy of human mesenchymal stromal cell (hMSC) with human mononuclear cell (hMNC) in treating rat cerebral infarct.Methods The SD rat models of cerebral infarct were established by distal middle cerebral artery occlusion (dMCAO). Rats were divided into four groups: sham,ischemia vehicle,MSC,and MNC transplantation groups. For the transplantation group,1×106 hMSCs or hMNCs were intravascularly transplanted into the tail vein 1 hour after the ischemia onset. The ischemia vehicle group received dMCAO surgery and intravascular saline injection 1,3,5,and 7 days after the ischemia onset,and then behavioral tests were performed. At 48 h after the ischemia onset,the abundance of Iba- 1,the symbol of activated microglia,was evaluated in the peri-ischemia striatum area; meanwhile,the neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) in ipsilateral peri-ischemia striatum area were also measured. Results The relative infarct volume in ischemia vehicle group,hMSC group,and hMNC transplantation group were (37.85±4.40)%,(33.41±3.82)%,and (30.23±3.63)%,respectively. The infarct volumes of MSC group (t=2.100,P=0.034) and MNC group (t=2.109,P=0.0009) were significantly smaller than that of ischemia vehicle group,and that of MNC group was significantly smaller than that of MSC group (t=1.743,P=0.043). One day after transplantation,the score of ischemia vehicle group in limb placing test was (4.32±0.71)%,which was significantly lower than that in sham group (9.73±0.36)% (t=2.178,P=8.61×10-11). The scores of MSC and MNC group,which were (5.09±0.62)% (t=2.1009,P=0.024) and (5.90±0.68)% (t=2.1008,P=0.0001),respectively,were significantly higher than that of ischemia vehicle group; also,the score of MNC group was significantly higher than that of MSC group(t=2.1009,P=0.0165). The contralateral forelimb scores of MSC and MNC groups in beam walking test were (5.56±0.86)% (t=2.120,P=0.020) and (5.13±0.95)% (t=2.131,P=0.003),were both significantly lower than that of ischemia vehicle group [(6.47±0.61)%]. Three days after the transplantation,the limb placing test score of MNC group [(6.91±1.10)%] was significantly higher than that of ischemia vehicle group (5.80±0.82)% (t=2.110,P=0.027). The score of MSC group [(6.30±0.77)%] showed no statistic difference with that of ischemia vehicle group(t=2.101,P=0.199).The contralateral forelimb scores of MNC group in beam walking test [(4.34±0.58)%] was significantly lower than that of ischemia vehicle group [(5.31±0.65)%] (t=2.100,P=0.006) and MSC group [(4.92±0.53)%] (t=2.100,P=0.041); there was no statistic difference between MSC group and ischemia vehicle group (t=2.109,P=0.139). The relative abundance of Iba- 1 in sham,ischemia vehicle,MSC,and MNC groups was 1.00+0.00,1.72±0.21,1.23±0.08,and 1.48±0.06,respectively. The Iba-1 relative abundance of ischemia vehicle group was significantly higher than that of sham group (t=2.262,P=2.9×10-6). The Iba-1 relative abundances of both MSC (t=2.178,P=3.91×10-5)and MNC (t=2.200,P=0.007)groups were significantly lower than that of ischemia vehicle group. It was also significantly lower in MNC group than in MSC group also (t=2.120,P=7.09×10-6). Three days after transplantation,the BDNF and GDNF levels of MSC group,which were (531.127±73.176)pg/mg (t=2.109,P=0.003)and(127.780±16.733)pg/mg(t=2.100,P=2.76×10-5),respectively,were significantly higher than those of ischemia vehicle group,which were (401.988±89.006)pg/mg and (86.278±14.832) pg/mg,respectively. The BDNF and GDNF levels of MNC group,which were (627.429±65.646)pg/mg (t=2.144,P=0.017) and (153.117±20.443)pg/mg (t=2.109,P=0.010),respectively,were all significantly higher than that of MSC group. At day 7,the BDNF and GDNF levels of MSC group,which were (504.776±83.282)pg/mg (t=2.101,P=0.005) and (81.641±11.019)pg/mg (t=2.100,P=0.002),respectively,were significantly higher than those of ischemia vehicle group,which were (389.257±70.440)pg/mg and (64.322±9.855) pg/mg,respectively. The BDNF and GDNF levels of MNC group,which were (589.068±63.323)pg/mg (t=2.100,P=0.027) and (102.161±19.932)pg/mg (t=2.144,P=0.017),respectively,were all significantly higher than that of MSC group. Conclusions Both hMSC and hMNC are beneficial to the ischemia-damaged brain when they are intravascularly transplanted within 1 h after the onset of ischemia. The anti-inflammation ability and secretion of neurotrophic factors are the underlying mechanisms of the therapeutic effects. MNC is more effective than MSC in reducing infarct area and improving behaviors,which might be explained by the fact that MNC induces more GDNF and BDNF in brain than MSC.