scholarly journals The Impact of Fixation on the Detection of Oligodendrocyte Precursor Cell Morphology and Vascular Associations

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1302
Author(s):  
Friederike Pfeiffer ◽  
Amin Sherafat ◽  
Akiko Nishiyama
Keyword(s):  
Growth Factor Receptor ◽  
Fluorescence Signal ◽  
Oligodendrocyte Precursor Cells ◽  
Oligodendrocyte Precursor Cell ◽  
Brain Vasculature ◽  
Factor Receptor Alpha ◽  
Oligodendrocyte Precursor ◽  
The Impact ◽  
The Brain ◽  
Surrounding Parenchyma

Oligodendrocyte precursor cells (OPCs) display numerous protrusions that extend into the surrounding parenchyma in the brain. Depending on the preparation of the tissue analyzed, these protrusions are more or less visible. We applied six different fixation methods and compared the effect of prolonged and stronger fixation on fluorescence intensity of platelet-derived growth factor receptor alpha, a surface marker of OPCs. Importantly, the fluorescence signal is mostly lost on protrusions as compared to the cell body, which has to be considered for specific analyses. Additionally, we show numerous contacts established between OPCs and the brain vasculature, which will contribute to the understanding of the interactions between these two elements.

scholarly journals Expression of Oligodendrocyte Precursor Cell Markers in Canine Oligodendrogliomas

2018 ◽  
Vol 55 (5) ◽  
pp. 634-644 ◽  
Author(s):  
Takuya E. Kishimoto ◽  
Kazuyuki Uchida ◽  
Atigan Thongtharb ◽  
Tokuhiro Shibato ◽  
James K. Chambers ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Cyst Formation ◽  
Precursor Cell ◽  
Platelet Derived Growth Factor ◽  
Oligodendrocyte Precursor Cells ◽  
Oligodendrocyte Precursor Cell ◽  
Myxoid Matrix ◽  
Oligodendrocyte Precursor ◽  
French Bulldog ◽  
Potential Origin

Oligodendroglioma is a common brain tumor in dogs, particularly brachycephalic breeds. Oligodendrocyte precursor cells (OPCs) are suspected to be a possible origin of oligodendroglioma, although it has not been well elucidated. In the present study, 27 cases of canine brain oligodendrogliomas were histologically and immunohistochemically examined. The most commonly affected breed was the French Bulldog ( n = 19 of 27, 70%). Seizure was the most predominant clinical sign ( n = 17 of 25, 68%). The tumors were located mainly in the cerebrum, particularly in the frontal lobe ( n = 10 of 27, 37%). All cases were diagnosed as anaplastic oligodendroglioma (AO) and had common histologic features characterized by the proliferation of round to polygonal cells with pronounced atypia and conspicuous mitotic activity (average, 10.7 mitoses per 10 high-power fields). Honeycomb pattern ( n = 5 of 27, 19%), myxoid matrix ( n = 10, 37%), cyst formation ( n = 6, 22%), necrosis ( n = 19, 70%), pseudopalisading ( n = 5, 18.5%), glomeruloid vessels ( n = 16, 59%), and microcalcification ( n = 5, 19%) were other histopathologic features of the present tumors. Immunohistochemically, the tumor cells were positive for Olig2 in all cases and for other markers of OPCs in most cases, including SOX10 ( n = 24 of 27, 89%), platelet-derived growth factor receptor α ( n = 24, 89%), and NG2 ( n = 23, 85%). The present AO also consisted of heterogeneous cell populations that were positive for nestin ( n = 13 of 27, 48%), glial fibrillary acidic protein ( n = 5, 19%), doublecortin ( n = 22, 82%), and βIII-tubulin ( n = 15, 56%). Moreover, cultured AO cells obtained from 1 case retained expression of OPC markers and exhibited multipotent characteristics in a serum culture condition. Overall, the findings suggest that transformed multipotent OPCs may be a potential origin of canine AO.

Abstract TMP30: M2 Microglia Derived Exosomes Promote White Matter Repair and Long-Term Functional Recovery After Focal Cerebral Ischemia in Mice

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Yongfang Li ◽  
Longlong Luo ◽  
Zhijun Zhang ◽  
Yaohui Tang ◽  
Guo-Yuan Yang
Keyword(s):  
White Matter ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Oligodendrocyte Precursor Cells ◽  
Oligodendrocyte Precursor Cell ◽  
M2 Microglia ◽  
Oligodendrocyte Precursor ◽  
White Matter Repair ◽  
Exosomal Mirna

Objectives: White matter injury aggravates neurological and cognitive impairment in experimental ischemic stroke. M2 microglia promote oligodendrocyte precursor cells survival and differentiation, and further enhance white matter repair. However, the molecular mechanism is unclear. Here, we explored the effect and mechanism of M2 microglia-derived exosomes on white matter repair after focal cerebral ischemia in mice. Methods: Microglia BV2 cells were polarized to M2 phenotype by IL-4 stimulation. Exosomes were isolated from M2 microglia (M2-Exo) and unstimulated microglia as a control (M0-Exo). M2-Exo and M0-Exo (100 μg) were intravenously injected after 90-minute middle cerebral artery occlusion in mice (n=72). Brain atrophy volume and neuro behavioral outcomes were examined in 28 days following focal cerebral ischemia. Oligodendrocyte precursor cells survival, differentiation and white matter integrity were evaluated. Exosomal miRNA and target gene were further examined to explore molecular mechanism. Results: M2-Exo treatment promoted sensorimotor and memory function recovery ( p <0.05), and further reduced brain atrophy compared to the M0-Exo control group ( p <0.001). Immunostaining showed that M2-Exo increased the number of BrdU + /Pdgfr-α + and BrdU + /adenomatous polyposis coli + cells, enhanced myelin basic protein fluorescence-intensity compared to the control ( p <0.05). M2-Exo increased oligodendrocyte precursor cell survival under OGD in vi tro , ( p <0.05) and differentiation ( p <0.05). Exosomal miRNA sequencing and PCR identified that miR-23a-5p was enriched in M2-Exo. Conclusion: Our results showed that M2-Exo treatment enhanced oligodendrocyte precursor cell survival and differentiation, further promoted white matter repair and long-term functional recovery, suggesting that M2-Exo is a novel therapeutic strategy for the white matter repair after ischemic brain injury.

scholarly journals Oligodendrocyte precursor cells transplantation protects blood–brain barrier in a mouse model of brain ischemia via Wnt/β-catenin signaling

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Liping Wang ◽  
Jieli Geng ◽  
Meijie Qu ◽  
Fang Yuan ◽  
Yuyang Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Blood Brain Barrier ◽  
Precursor Cells ◽  
Precursor Cell ◽  
Brain Barrier ◽  
Oligodendrocyte Precursor Cells ◽  
Oligodendrocyte Precursor Cell ◽  
Blood Brain ◽  
Oligodendrocyte Precursor ◽  
Blood Brain Barrier Integrity

AbstractBlood–brain barrier damage is a critical pathological feature of ischemic stroke. Oligodendrocyte precursor cells are involved in maintaining blood–brain barrier integrity during the development. However, whether oligodendrocyte precursor cell could sustain blood–brain barrier permeability during ischemic brain injury is unknown. Here, we investigate whether oligodendrocyte precursor cell transplantation protects blood–brain barrier integrity and promotes ischemic stroke recovery. Adult male ICR mice (n = 68) underwent 90 min transient middle cerebral artery occlusion. After ischemic assault, these mice received stereotactic injection of oligodendrocyte precursor cells (6 × 105). Oligodendrocyte precursor cells transplantation alleviated edema and infarct volume, and promoted neurological recovery after ischemic stroke. Oligodendrocyte precursor cells reduced blood–brain barrier leakage via increasing claudin-5, occludin and β-catenin expression. Administration of β-catenin inhibitor blocked the beneficial effects of oligodendrocyte precursor cells. Wnt7a protein treatment increased β-catenin and claudin-5 expression in endothelial cells after oxygen–glucose deprivation, which was similar to the results of the conditioned medium treatment of oligodendrocyte precursor cells on endothelial cells. We demonstrated that oligodendrocyte precursor cells transplantation protected blood–brain barrier in the acute phase of ischemic stroke via activating Wnt/β-catenin pathway. Our results indicated that oligodendrocyte precursor cells transplantation was a novel approach to the ischemic stroke therapy.

scholarly journals Vitamins D3 and D2 have marked but different global effects on gene expression in a rat oligodendrocyte precursor cell line

2019 ◽  
Author(s):  
Manuela Mengozzi ◽  
Andrew Hesketh ◽  
Giselda Bucca ◽  
Pietro Ghezzi ◽  
Colin P. Smith
Keyword(s):  
Gene Expression ◽  
Vitamin D ◽  
Clinical Course ◽  
Notch Pathway ◽  
Vitamin D2 ◽  
Oligodendrocyte Precursor Cells ◽  
Oligodendrocyte Precursor Cell ◽  
Ras Pathway ◽  
Precursor Cell Line ◽  
Oligodendrocyte Precursor

AbstractVitamin D deficiency increases the risk of developing multiple sclerosis (MS) but there is uncertainty about what dose and form of vitamin D could improve the clinical course of MS. The mechanisms underlying the effects of vitamin D in MS are not clear. Vitamin D3 increases the rate of differentiation of primary oligodendrocyte precursor cells (OPCs), suggesting that it might help remyelination in addition to modulating the immune response. Here we analyzed the transcriptome of differentiating rat CG4 OPCs treated with vitamin D2 or with D3 at 24 h and 72 h following onset of differentiation. Differentiation alone changed the expression of about 10% of the genes at 72 h compared to 24 h. Vitamin D2 and D3 exerted different effects on gene expression, with D3 influencing 1,272 genes and D2 574 at 24 h. The expression of the vast majority of these genes was either not changed in differentiating cells not exposed to vitamin D or followed the same trajectory as the latter. D3-repressed genes were enriched for gene ontology categories including transcription factors and the Notch pathway, while D3-induced genes were enriched for the Ras pathway. These findings should help to identify mechanisms mediating D3 action in MS.

scholarly journals Impact of Tau on Neurovascular Pathology in Alzheimer's Disease

2021 ◽  
Vol 11 ◽  
Author(s):  
Elisa Canepa ◽  
Silvia Fossati
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Neurovascular Unit ◽  
Amyloid Angiopathy ◽  
Brain Vasculature ◽  
Mitochondrial Alterations ◽  
Species Production ◽  
The Impact ◽  
The Brain

Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the most prevalent cause of dementia. The main cerebral histological hallmarks are represented by parenchymal insoluble deposits of amyloid beta (Aβ plaques) and neurofibrillary tangles (NFT), intracellular filamentous inclusions of tau, a microtubule-associated protein. It is well-established that cerebrovascular dysfunction is an early feature of AD pathology, but the detrimental mechanisms leading to blood vessel impairment and the associated neurovascular deregulation are not fully understood. In 90% of AD cases, Aβ deposition around the brain vasculature, known as cerebral amyloid angiopathy (CAA), alters blood brain barrier (BBB) essential functions. While the effects of vascular Aβ accumulation are better documented, the scientific community has only recently started to consider the impact of tau on neurovascular pathology in AD. Emerging compelling evidence points to transmission of neuronal tau to different brain cells, including astrocytes, as well as to the release of tau into brain interstitial fluids, which may lead to perivascular neurofibrillar tau accumulation and toxicity, affecting vessel architecture, cerebral blood flow (CBF), and vascular permeability. BBB integrity and functionality may therefore be impacted by pathological tau, consequentially accelerating the progression of the disease. Tau aggregates have also been shown to induce mitochondrial damage: it is known that tau impairs mitochondrial localization, distribution and dynamics, alters ATP and reactive oxygen species production, and compromises oxidative phosphorylation systems. In light of this previous knowledge, we postulate that tau can initiate neurovascular pathology in AD through mitochondrial dysregulation. In this review, we will explore the literature investigating tau pathology contribution to the malfunction of the brain vasculature and neurovascular unit, and its association with mitochondrial alterations and caspase activation, in cellular, animal, and human studies of AD and tauopathies.

scholarly journals Study on the Safety of Human Oligodendrocyte Precursor Cells Transplantation in Young Animals and Its Efficacy on Myelination

2021 ◽  
Author(s):  
Haipeng Zhou ◽  
Siliang Lu ◽  
Ke Li ◽  
Yinxiang Yang ◽  
Caiyan Hu ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Vital Signs ◽  
Precursor Cells ◽  
Tumor Formation ◽  
Oligodendrocyte Precursor Cells ◽  
Sprague Dawley ◽  
Tissue Proliferation ◽  
Developmental Indicators ◽  
Oligodendrocyte Precursor ◽  
The Brain

Abstract Oligodendrocyte precursor cells (OPCs), which can differentiate into myelinating oligodendrocytes during embryonic development, are an important potential source for myelin repair or regeneration. To date, OPCs from human sources (hOPCs) remain limited. In this study, we aimed to evaluate the safety and remyelination capacity of hOPCs developed in our laboratory by transplanting them into the lateral ventricles of Sprague–Dawley rats of different ages. The toxicity, biodistribution, and tumor formation abilities of the injected hOPCs were examined by evaluating rats’ vital signs, developmental indicators, neural reflexes, along with hematological, immunological, and pathological assessments. In addition, the hOPCs were transplanted into the corpus callosum of shiverer mice to verify cell myelination efficacy. Overall, our results showed that transplanted hOPCs into young mice showed no toxicity against their organ function or immune system, engrafted only in the brain, and caused no tissue proliferation or tumor formation. In terms of efficacy, the transplanted hOPCs formed myelin in the corpus callosum, alleviated the trembling phenotype of shiverer mice, and promoted normal development. The transplantation of hOPCs is safe and can effectively form myelin in the brain, thereby providing a theoretical basis for the future clinical transplantation of hOPCs.

Oligodendrocyte precursor cell transplantation promotes angiogenesis and remyelination via Wnt/β-catenin pathway in a mouse model of middle cerebral artery occlusion

2021 ◽  
pp. 0271678X2110653
Author(s):  
Li-Ping Wang ◽  
Jiaji Pan ◽  
Yongfang Li ◽  
Jieli Geng ◽  
Chang Liu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Cell Transplantation ◽  
Artery Occlusion ◽  
Precursor Cells ◽  
Precursor Cell ◽  
Oligodendrocyte Precursor Cells ◽  
Oligodendrocyte Precursor Cell ◽  
Oligodendrocyte Precursor ◽  
Cerebral Artery Occlusion

White matter injury is a critical pathological characteristic during ischemic stroke. Oligodendrocyte precursor cells participate in white matter repairing and remodeling during ischemic brain injury. Since oligodendrocyte precursor cells could promote Wnt-dependent angiogenesis and migrate along vasculature for the myelination during the development in the central nervous system, we explore whether exogenous oligodendrocyte precursor cell transplantation promotes angiogenesis and remyelination after middle cerebral artery occlusion in mice. Here, oligodendrocyte precursor cell transplantation improved motor and cognitive function, and alleviated brain atrophy. Furthermore, oligodendrocyte precursor cell transplantation promoted functional angiogenesis, and increased myelin basic protein expression after ischemic stroke. The further study suggested that white matter repairing after oligodendrocyte precursor cell transplantation depended on angiogenesis induced by Wnt/β-catenin signal pathway. Our results demonstrated a novel pathway that Wnt7a from oligodendrocyte precursor cells acting on endothelial β-catenin promoted angiogenesis and improved neurobehavioral outcomes, which facilitated white matter repair and remodeling during ischemic stroke.

scholarly journals Connecting Neuroinflammation and Neurodegeneration in Multiple Sclerosis: Are Oligodendrocyte Precursor Cells a Nexus of Disease?

2021 ◽  
Vol 15 ◽  
Author(s):  
Morgan W. Psenicka ◽  
Brandon C. Smith ◽  
Rachel A. Tinkey ◽  
Jessica L. Williams
Keyword(s):  
Multiple Sclerosis ◽  
Animal Models ◽  
Active Role ◽  
Precursor Cells ◽  
Oligodendrocyte Precursor Cells ◽  
Secreted Factors ◽  
Autoimmune Pathology ◽  
The Central Nervous System ◽  
Oligodendrocyte Precursor ◽  
The Impact

The pathology in neurodegenerative diseases is often accompanied by inflammation. It is well-known that many cells within the central nervous system (CNS) also contribute to ongoing neuroinflammation, which can promote neurodegeneration. Multiple sclerosis (MS) is both an inflammatory and neurodegenerative disease in which there is a complex interplay between resident CNS cells to mediate myelin and axonal damage, and this communication network can vary depending on the subtype and chronicity of disease. Oligodendrocytes, the myelinating cell of the CNS, and their precursors, oligodendrocyte precursor cells (OPCs), are often thought of as the targets of autoimmune pathology during MS and in several animal models of MS; however, there is emerging evidence that OPCs actively contribute to inflammation that directly and indirectly contributes to neurodegeneration. Here we discuss several contributors to MS disease progression starting with lesion pathology and murine models amenable to studying particular aspects of disease. We then review how OPCs themselves can play an active role in promoting neuroinflammation and neurodegeneration, and how other resident CNS cells including microglia, astrocytes, and neurons can impact OPC function. Further, we outline the very complex and pleiotropic role(s) of several inflammatory cytokines and other secreted factors classically described as solely deleterious during MS and its animal models, but in fact, have many neuroprotective functions and promote a return to homeostasis, in part via modulation of OPC function. Finally, since MS affects patients from the onset of disease throughout their lifespan, we discuss the impact of aging on OPC function and CNS recovery. It is becoming clear that OPCs are not simply a bystander during MS progression and uncovering the active roles they play during different stages of disease will help uncover potential new avenues for therapeutic intervention.

scholarly journals Acute and chronic stage adaptations of vascular architecture and cerebral blood flow in a mouse model of TBI

2018 ◽  
Author(s):  
Joe Steinman ◽  
Lindsay S. Cahill ◽  
Margaret M. Koletar ◽  
Bojana Stefanovic ◽  
John G. Sled
Keyword(s):  
Blood Flow ◽  
Ex Vivo ◽  
Vessel Density ◽  
Vascular Architecture ◽  
Two Photon ◽  
Brain Vasculature ◽  
The Impact ◽  
The Brain ◽  
Time Point

AbstractThe 3D organization of cerebral blood vessels determines the overall capacity of the cerebral circulation to meet the metabolic requirements of the brain. This study used Arterial Spin Labeling (ASL) MRI with a hypercapnic challenge and ex vivo Serial Two-Photon Tomography (STPT) to examine the relationship between blood flow and 3D microvascular structure following traumatic brain injury (TBI) in a mouse. Mice were exposed to a controlled cortical impact TBI and allowed to recover for either 1 day or 4 weeks. At each time point, ASL MRI was performed to quantify cerebral perfusion and the brain vasculature was imaged in 3D with STPT. Registration of ASL to STPT enabled flow changes to be related to the underlying microvascular structure in each ASL voxel. Hypoperfusion under rest and hypercapnia was observed both 1 day and 4 weeks post-TBI. Vessel density and vascular volume were reduced 1 day post-TBI, recovering by 4 weeks; however, the reorganized vasculature at the latter time point possessed an abnormal radial pattern. Our findings demonstrate functionally significant long-term changes in the vascular architecture following injury and illustrate why metrics beyond traditional measures of vessel density are required to understand the impact of vascular structure on function.

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