Human-Derived Induced GABAergic Progenitor Cells Improve Cognitive Function in Mice and Inhibit Astrocyte Activation with Anti-Inflammatory Exosomes.

OBJECTIVE: The role of gamma-aminobutyric acid-ergic (GABAergic) neuron impairment in Alzheimer's disease (AD), and if and how transplantation of healthy GABAergic neurons can improve AD, remain unknown. METHODS: Human-derived medial ganglionic eminence progenitors (hiMGEs) differentiated from programmed induced neural precursor cells (hiNPCs) were injected into the dentate gyrus region of the hippocampus (HIP). RESULTS: We showed that grafts migrate to the whole brain and form functional synaptic connections in amyloid precursor protein gene/ presenilin-1 (APP/PS1) chimeric mice. Following transplantation of hiMGEs, behavioral deficits and AD-related pathology were alleviated and defective neurons were repaired. Notably, exosomes secreted from hiMGEs, which are rich in anti-inflammatory miRNA, inhibited astrocyte activation in vitro and in vivo, and the mechanism was related to regulation of CD4+ Th1 cells mediated tumor necrosis factor (TNF) pathway. INTERPRETATION: Taken together, these findings support the hypothesis that hiMGEs transplantation is an alternative treatment for neuronal loss in AD and demonstrate that exosomes with anti-inflammatory activity derived from hiMGEs are important factors for graft survival. ANN NEUROL 2024.

Estimating Flow Direction of Circle of Willis Using Dynamic Arterial Spin Labeling Magnetic Resonance Angiography.

BACKGROUND AND PURPOSE: The Circle of Willis (COW) is a crucial mechanism for cerebral collateral circulation. This proof-ofconcept study aims to develop and assess an analysis method to characterize the hemodynamics of the arterial segments in COW using arterial spin labeling (ASL) based non-contrast enhanced dynamic magnetic resonance angiography (dMRA). MATERIALS AND METHODS: The developed analysis method uses a graph model, bootstrap strategy, and ensemble learning methodologies to determine the time-curve shift from ASL dMRA to estimate the flow direction within the COW. The performance of the method was assessed on 52 subjects, using the flow direction, either antegrade or retrograde, derived from 3D phase contrast (PC) MRI as the reference. RESULTS: A total of 340 arterial segments in COW were evaluated, among which 30 (8.8%) had retrograde flow according to 3D PC. The ASL dMRA-based flow direction estimation has an accuracy, sensitivity, and specificity of 95.47%, 80%, and 96.34%, respectively. CONCLUSIONS: Using ASL dMRA and the developed image analysis method to estimate the flow direction in COW is feasible. This study provides a new method to assess the hemodynamics of the COW, which could be useful for the diagnosis and study of cerebrovascular diseases. ABBREVIATIONS: COW = Circle of Willis; ASL = arterial spin labeling; dMRA =dynamic magnetic resonance angiography; PC = phase contrast.

Accurate and robust segmentation of cerebral vasculature on four-dimensional arterial spin labeling magnetic resonance angiography using machine-learning approach.

Segmentation of cerebral vasculature on MR vascular images is of great significance for clinical application and research. However, the existing cerebrovascular segmentation approaches are limited due to insufficient image contrast and complicated algorithms. This study aims to explore the potential of the emerging four-dimensional arterial spin labeling magnetic resonance angiography (4D ASL-MRA) technique for fast and accurate cerebrovascular segmentation with a simple machine-learning approach. Nine temporal features were extracted from the intensity-time signal of each voxel, and eight spatial features from the neighboring voxels. Then, the unsupervised outlier detection algorithm, i.e. Isolation Forest, is used for segmentation of the vascular voxels based on the extracted features. The total length of the centerlines of the intracranial arterial vasculature, the dice similarity coefficient (DSC), and the average Hausdorff Distance (AVGHD) on the cross-sections of small- to large-sized vessels were calculated to evaluate the performance of the segmentation approach on 4D ASL-MRA of 18 subjects. Experiments show that the temporal information on 4D ASL-MRA can largely improve the segmentation performance. In addition, the proposed segmentation approach outperforms the traditional methods that were performed on the 3D image (i.e. the temporal average intensity projection of 4D ASL-MRA) and the previously proposed frame-wise approach. In conclusion, this study demonstrates that accurate and robust segmentation of cerebral vasculature is achievable on 4D ASL-MRA by using a simple machine-learning approach with appropriate features.

Therapeutic effects against high-grade glioblastoma mediated by engineered induced neural stem cells combined with GD2-specific CAR-NK.

PURPOSE: High-grade glioblastoma is extremely challenging to treat because of its aggressiveness and resistance to conventional chemo- and radio-therapies. On the contrary, genetic and cellular immunotherapeutic strategies based on the stem and immune cells are emerging as promising treatments against glioblastoma (GBM). We aimed to developed a novel combined immunotherapeutic strategy to improve the treatment efficacy using genetically engineered PBMC-derived induced neural stem cells (iNSCs) expressing HSV-TK and second-generation CAR-NK cells against GBM. METHODS: iNSCs cells expressing HSV-TK (iNSCsTK) and GD2-specific CAR-NK92 (GD2NK92) were generated from PBMC-derived iNSCs and NK92 cell lines, respectively. The anti-tumor effect of iNSCsTK and the combinational therapeutics of iNSCsTK and GD2NK92 were evaluated by GBM cell line using in vitro and in vivo experiments. RESULTS: PBMC-derived iNSCsTK possessed tumor-tropism migration ability in vitro and in vivo, which exhibited considerable anti-tumor activity via bystander effect in the presence of ganciclovir (GCV). iNSCsTK/GCV could slow GBM progression and prolong median survival in tumor-bearing mice. However, the anti-tumor effect was limited to single therapy. Therefore, the combinational therapeutic effect of iNSCsTK/GCV and GD2NK92 against GBM was investigated. This approach displayed a more significant anti-tumor effect in vitro and in xenograft tumor mice. CONCLUSIONS: PBMC-derived iNSCsTK showed a significant tumor-tropic migration and an effective anti-tumor activity with GCV in vitro and in vivo. In addition, combined with GD2NK92, iNSCsTK therapeutic efficacy improved dramatically to prolong the tumor-bearing animal model's median survival.

GABAergic signaling abnormalities in a novel CLU mutation Alzheimer's disease mouse model.

The CLU rs11136000C mutation (CLUC) is the third most common risk factor for Alzheimer's disease (AD). However, the mechanism by which CLUC leads to abnormal GABAergic signaling in AD is unclear. To address this question, this study establishes the first chimeric mouse model of CLUC AD. Examination of grafted CLUC medial ganglionic eminence progenitors (CLUC hiMGEs) revealed increased GAD65/67 and a high frequency of spontaneous releasing events. CLUC hiMGEs also impaired cognition in chimeric mice and caused AD-related pathologies. The expression of GABA A receptor, subunit alpha 2 (Gabrα2) was higher in chimeric mice. Interestingly, cognitive impairment in chimeric mice was reversed by treatment with pentylenetetrazole, which is a GABA A receptor inhibitor. Taken together, these findings shed light on the pathogenesis of CLUC AD using a novel humanized animal model and suggest sphingolipid signaling over-activation as a potential mechanism of GABAergic signaling disorder.

Rosai-Dorfman disease with spinal and multiple intracranial involvement: a case report and literature review.

Rosai-Dorfman disease (RDD) is a condition of unknown etiology, and characterized by the proliferation of histiocytes. RDD most commonly affects lymph nodes, and central nervous system (CNS) involvement is rare. Here, we describe the case of a 43-year-old man who presented with an intradural tumour of the thoracic spine. The patient underwent a laminectomy for tumour resection and pathology results diagnosed the tumour as a RDD. Two years later, brain magnetic resonance imaging (MRI) revealed multiple intracranial dural-based lesions. Prednisolone treatment was initiated and led to resolution of the disease. We reviewed the literature to the investigate clinical characteristics, imaging features, diagnosis and treatment protocols pertaining to such cases.

LOX-1 Deletion Attenuates Myocardial Fibrosis in the Aged Mice, Particularly Those With Hypertension.

Background: Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a transmembrane glycoprotein that mediates uptake of oxidized low-density lipoprotein (ox-LDL) into cells. Previous studies had shown that LOX-1 deletion had a potential to inhibit cardiac fibrosis in mouse models of hypertension and myocardial infarction. Whether LOX-1 deletion also affects cardiac fibrosis associated with aging still remains unknown. The aim of this study was to investigate the effect of LOX-1 deletion on myocardial fibrosis in the aged mice. Methods: C57BL/6 mice and LOX-1 knockout (KO) mice with C57BL/6 background were studied to the age of 60 weeks. Both genotypes of aged mice were exposed to angiotensin II (Ang II) or saline for additional 4 weeks. The mice were then sacrificed, and myocardial fibrosis, reactive oxygen species (ROS) and expression of LOX-1, fibronectin, collagens, p22phox, and gp91phox were measured. Results: LOX-1 deletion markedly reduced Ang II-mediated rise of blood pressure in the aged mice (vs. saline-treated mice). LOX-1 deletion also limited fibrosis and decreased fibronectin and collagen-3 expression in the hearts of aged mice, but not the expression of collagen-1 and collagen-4. LOX-1 deletion also inhibited ROS production and p22phox expression. As the aged mice were exposed to Ang II for 4 weeks (resulting in hypertension), LOX-1 deletion more pronounced inhibiting myocardial fibrosis and ROS production, and decreasing expression of fibronectin, collagen-1, collagen-2, collagen-3, p22phox, and gp91phox. Conclusion: LOX-1 deletion limited fibrosis and ROS production in the hearts of aged mice. This effect was more pronounced in the aged mice with hypertension induced by Ang II infusion.

Increased risk of Ventriculostomy-Associated hemorrhage in patients treated with antiplatelet agents for stent-assisted coiling of ruptured intracranial aneurysms.

PURPOSE: The aim of this study is to evaluate the impact of antiplatelet agents for stent-assisted coiling, including intravenous (IV) tirofiban as an antiplatelet premedication, on rates of external ventricular drain (EVD)-related hemorrhage in acutely ruptured intracranial aneurysms. The impact of IV tirofiban in particular was also evaluated. METHODS: Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who received an antiplatelet agent for stent-assisted coil embolization (SACE), and patients who did not receive an antiplatelet agent between June 2013 and June 2019. RESULTS: 78 patients treated for a ruptured aneurysm which required an EVD were included. A total of 46 patients who underwent stent-assisted coiling and received IV tirofiban and oral asipirin and clopidogrel (DAPT) were included in the antiplatelet group, while 32 who underwent single coiling and received no antiplatelet therapy were included in the control group. Overall, EVD-related hemorrhage occurred in 13 patients (16.67%): 11 (23.91%) in the antiplatelet group and 2 (6.25%) in the control group (p = 0.040). Of 37 patients who underwent computed tomography after SACE, but before the use of DAPT, 8 (21.62%) exhibited EVD-related hemorrhage after IV tirofiban therapy (p = 0.070 vs. control group). EVD-related hemorrhage was not significantly different between patients with EVD placement after coil embolization versus before coil embolization (p = 0.124). In the subgroup analysis for the antiplatelet group, we did not observed increased EVD-related hemorrhage in patients receiving EVD placement after administration of antiplatelet agents (8/27 [29.63%]) versus before administration of antiplatelet agents (3/19 [15.79%]). CONCLUSION: Patients with ruptured aneurysm who receive an antiplatelet agent for stent-assisted coiling are at a higher risk for EVD-related hemorrhage. The order of EVD placement and EVT, as well as the order of EVD placement and antiplatelet initiation do not appear to be significantly different regarding the outcome of EVD-related hemorrhage.HighlightsPatients with ruptured aneurysm who receive an antiplatelet agent for stent-assisted coiling are at a higher risk for EVD-related hemorrhage.There was a trend towards higher EVD related haemorrhage when tirofiban was used but it did not reach statisitical significance.The order of EVD-whether before vs after endovascular treatment, or before vs after antiplatelet therapy did not influence the EVD-related hemorrhage rates.

Induced neural stem cells-derived spinal cord progenitor cells as stable stage for rapid and efficient generation of human oligodendrocytes and motor neurons.

Purpose: Previous studies have shown that oligodendrocytes and motor neurons have the same progenitors in the ventral spinal cord called spinal cord progenitor cells marked by oligodendrocyte lineage transcription factor 2 (Olig2). However, it is difficult to identify the spinal cord progenitor cell in vitro as they are present transiently and further transform into other neuronal (interneuron) and glial (oligodendrocyte) lineages during development. In the present study, we try to generated Olig2+ spinal cord progenitor cells from human induced neural stem cells (iNSCs) and identify those spinal cord progenitor cells in vitro Materials and Methods: Human peripheral blood mononuclear cells (PBMCs) were converted into induced neural stem cells (iNSCs), after they were identified by immunostaining using neural stem cell markers such as Nestin, Sox1, Sox2, iNSCs were transformed into Olig2+ spinal cord progenitor cells in 3 weeks by using small molecules. Results: Olig2+ spinal cord progenitor cells could expand for at least five passages and remained in a dividing state over a considerable period of time; in addition, the Olig2+ progenitor cells could mature into O4 and MBP positive oligodendrocytes and HB9 positive motor neurons in a short period. Conclusion: Our research provides a useful protocol for rapid generation of human oligodendrocytes and motor neurons from human iNSCs and demonstrates a progenitor cell model for exploring the origin of motor neurons and oligodendrocyte in vitro, which will contribute to research on the development of spinal cord and regenerative medicine.

Dopaminergic precursors differentiated from human blood-derived induced neural stem cells improve symptoms of a mouse Parkinson's disease model.

Autologous neural stem cells (NSCs) may offer a promising source for deriving dopaminergic (DA) cells for treatment of Parkinson's disease (PD). Methods: By using Sendai virus, human peripheral blood mononuclear cells (PBMNCs) were reprogrammed to induced NSCs (iNSCs), which were then differentiated to dopaminergic neurons in vitro. Whole-genome deep sequencing was performed to search for mutations that had accumulated during the reprogramming and expansion processes. To find the optimal differentiation stage of cells for transplantation, DA precursors obtained at various differentiation time points were tested by engraftment into brains of naïve immunodeficient mice. At last, the safety and efficacy of iNSC-derived DA precursors were tested by transplantation into the striatum of immunodeficient PD mouse models. Results: PBMNC-derived iNSCs showed similar characteristics to fetal NSCs, and were able to specifically differentiate to DA neurons with high efficiency in vitro. The sequencing data proved that no harmful SNVs, Indels and CNVs were generated during the reprogramming and expansion processes. DA precursors obtained between differentiation day 10 to 13 in vitro were most suitable for transplantation when a balanced graft survival and maturation were taken into account. Two weeks after transplantation of DA precursors into mouse PD models, the motor functions of PD mice started to improve, and continued to improve until the end of the experiments. No graft overgrowth or tumor was observed, and a significant number of A9-specific midbrain DA neurons were surviving in the striatum. Conclusion: This study confirmed the efficacy of iNSC-derived DA precursors in a mouse PD model, and emphasized the necessity of genomic sequencing and vigorous safety assessment before any clinical translation using iNSCs.

Accelerated generation of oligodendrocyte progenitor cells from human induced pluripotent stem cells by forced expression of Sox10 and Olig2.

Oligodendrocyte progenitor cells (OPCs) hold great promise for treatment of dysmyelinating disorders, such as multiple sclerosis and cerebral palsy. Recent studies on generation of human OPCs mainly use human embryonic stem cells (hESCs) or neural stem cells (NSCs) as starter cell sources for the differentiation process. However, NSCs are restricted in availability and the present method for generation of oligodendrocytes (OLs) from ESCs often requires a lengthy period of time. Here, we demonstrated a protocol to efficiently derive OPCs from human induced pluripotent stem cells (hiPSCs) by forced expression of two transcription factors (2TFs), Sox10 and Olig2. With this method, PDGFRα+ OPCs can be obtained in 14 days and O4+ OPCs in 56 days. Furthermore, OPCs may be able to differentiate to mature OLs that could ensheath axons when co-cultured with rat cortical neurons. The results have implications in the development of autologous cell therapies.

Conversion of adult human peripheral blood mononuclear cells into induced neural stem cell by using episomal vectors.

Human neural stem cells (NSCs) hold great promise for research and therapy in neural diseases. Many studies have shown direct induction of NSCs from human fibroblasts, which require an invasive skin biopsy and a prolonged period of expansion in cell culture prior to use. Peripheral blood (PB) is routinely used in medical diagnoses, and represents a noninvasive and easily accessible source of cells. Here we show direct derivation of NSCs from adult human PB mononuclear cells (PB-MNCs) by employing episomal vectors for transgene delivery. These induced NSCs (iNSCs) can expand more than 60 passages, can exhibit NSC morphology, gene expression, differentiation potential, and self-renewing capability and can give rise to multiple functional neural subtypes and glial cells in vitro. Furthermore, the iNSCs carry a specific regional identity and have electrophysiological activity upon differentiation. Our findings provide an easily accessible approach for generating human iNSCs which will facilitate disease modeling, drug screening, and possibly regenerative medicine.

Autologous iPSC-derived dopamine neuron transplantation in a nonhuman primate Parkinson's disease model.

Autologous dopamine (DA) neurons are a new cell source for replacement therapy of Parkinson's disease (PD). In this study, we tested the safety and efficacy of autologous induced pluripotent stem cell (iPSC)-derived DA cells for treatment of a cynomolgus monkey PD model. Monkey bone marrow mesenchymal cells were isolated and induced to iPSCs, followed by differentiation into DA cells using a method with high efficiency. Autologous DA cells were introduced into the brain of a cynomolgus monkey PD model without immunosuppression; three PD monkeys that had received no grafts served as controls. The PD monkey that had received autologous grafts experienced behavioral improvement compared with that of controls. Histological analysis revealed no overgrowth of grafts and a significant number of surviving A9 region-specific graft-derived DA neurons. The study provided a proof-of-principle to employ iPSC-derived autologous DA cells for PD treatment using a nonhuman primate PD model.