The critical role of the immune system in brain function and dysfunction is well recognized, yet development of immune therapies for psychiatric diseases has been slow due to concerns about iatrogenic immune deficiencies. These concerns are emphasized by the lack of objective diagnostic tools in psychiatry. A promise to resolve this conundrum lies in the exploitation of extracellular vesicles (EVs) that are physiologically produced or can be synthetized. EVs regulate recipient cell functions and offer potential for EVs-based therapies. Intranasal EVs administration enables the targeting of specific brain regions and functions, thereby facilitating the design of precise treatments for psychiatric diseases. The development of such therapies requires navigating four dynamically interacting networks: neuronal, glial, immune, and EVs. These networks are profoundly influenced by brain fluid distribution. They are crucial for homeostasis, cellular functions, and intercellular communication. Fluid abnormalities, like edema or altered cerebrospinal fluid (CSF) dynamics, disrupt these networks, thereby negatively impacting brain health. A deeper understanding of the above-mentioned four dynamically interacting networks is vital for creating diagnostic biomarker panels to identify distinct patient subsets with similar neuro-behavioral symptoms. Testing the functional pathways of these biomarkers could lead to new therapeutic tools. Regulatory approval will depend on robust preclinical data reflecting progress in these interdisciplinary areas, which could pave the way for the design of innovative and precise treatments. Highly collaborative interdisciplinary teams will be needed to achieve these ambitious goals.

• MeSH
• Biomarkers MeSH
• Mental Disorders * therapy   immunology   metabolism   MeSH
• Extracellular Vesicles * immunology   metabolism   transplantation   MeSH
• Precision Medicine * methods   MeSH
• Humans MeSH
• Cell Communication MeSH
• Brain immunology   metabolism   MeSH
• Neuroglia * metabolism   immunology   MeSH
• Neurons * metabolism   immunology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Accumulation of misfolded α-synuclein (α-Syn) leads to the formation of Lewy bodies and is a major hallmark of Parkinson's disease (PD). The accumulation of α-Syn involves several post-translational modifications. Recently, though, glycation of α-Syn (advanced glycation end products) and activation of the receptor for advanced glycation end products (RAGE) have been linked to neuroinflammation, which leads to oxidative stress and accumulation of α-Syn. The present study aims to detect the effect of glycated α-Syn (gly-α-Syn)-induced synucleinopathy and loss of dopaminergic (DAergic) neurons in the development of PD. We isolated, purified, and prepared glycated recombinant human α-Syn using d-ribose. Gly-α-Syn was characterized by SDS-PAGE, intact mass analysis, and bottom-up peptide sequence through LC-HRMS/MS. The aggregation propensity of gly-α-Syn has been verified by morphological and shape analysis through Bio-AFM. The gly-α-Syn (2 μg/μL) was injected stereotaxically in the substantia nigra (SN) of ICR mice (3-4 months) and compared with the normal α-Syn, d ribose, and Tris-HCl/artificial CSF groups. 56 days postsurgery (DPS), an immunohistochemical examination was conducted to investigate gly-α-Syn-induced α-Syn accumulation, neuroinflammation, and neurodegeneration. The glycation of α-Syn led to the expression of transglutaminase 2 (TGM2), an enzyme that cross-linked with AGEs and may have caused the accumulation of α-Syn. Significant RAGE activation was also observed in gly-α-Syn, which might have induced glial cell activation, resulting in oxidative stress and, ultimately, apoptosis of dopaminergic neurons. It is important to note that TGM2, phosphorylated α-Syn, RAGE expression, and glial cell activation were only found in the gly-α-Syn group and not in the other groups. This suggests that gly-α-Syn plays a major role in synucleinopathy, neuroinflammation, and neurodegeneration. Overall, the present study demonstrated glycation of α-Syn as one of the important age-associated post-translational modifications that are involved in the degeneration of dopaminergic neurons, at least in a subset of the diabetic patients susceptible to developing PD.

• MeSH
• alpha-Synuclein * metabolism   MeSH
• Dopaminergic Neurons * metabolism   pathology   drug effects   MeSH
• Glycosylation MeSH
• Humans MeSH
• Mice, Inbred ICR MeSH
• Mice MeSH
• Neuroglia * metabolism   pathology   drug effects   MeSH
• Oxidative Stress MeSH
• Parkinson Disease * metabolism   pathology   MeSH
• Glycation End Products, Advanced metabolism   MeSH
• Receptor for Advanced Glycation End Products metabolism   MeSH
• Substantia Nigra metabolism   pathology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Glial cells expressing neuron-glial antigen 2 (NG2), also known as oligodendrocyte progenitor cells (OPCs), play a critical role in maintaining brain health. However, their ability to differentiate after ischemic injury is poorly understood. The aim of this study was to investigate the properties and functions of NG2 glia in the ischemic brain. Using transgenic mice, we selectively labeled NG2-expressing cells and their progeny in both healthy brain and after focal cerebral ischemia (FCI). Using single-cell RNA sequencing, we classified the labeled glial cells into five distinct subpopulations based on their gene expression patterns. Additionally, we examined the membrane properties of these cells using the patch-clamp technique. Of the identified subpopulations, three were identified as OPCs, whereas the fourth subpopulation had characteristics indicative of cells likely to develop into oligodendrocytes. The fifth subpopulation of NG2 glia showed astrocytic markers and had similarities to neural progenitor cells. Interestingly, this subpopulation was present in both healthy and post-ischemic tissue; however, its gene expression profile changed after ischemia, with increased numbers of genes related to neurogenesis. Immunohistochemical analysis confirmed the temporal expression of neurogenic genes and showed an increased presence of NG2 cells positive for Purkinje cell protein-4 at the periphery of the ischemic lesion 12 days after FCI, as well as NeuN-positive NG2 cells 28 and 60 days after injury. These results suggest the potential development of neuron-like cells arising from NG2 glia in the ischemic tissue. Our study provides insights into the plasticity of NG2 glia and their capacity for neurogenesis after stroke.

• MeSH
• Antigens metabolism   MeSH
• Astrocytes metabolism   MeSH
• Brain Ischemia * metabolism   MeSH
• Brain metabolism   MeSH
• Mice, Transgenic MeSH
• Mice MeSH
• Neural Stem Cells * metabolism   MeSH
• Neuroglia metabolism   MeSH
• Oligodendroglia metabolism   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Naringin inhibits inflammation and oxidative stress, the P2 purinoreceptor X4 receptor (P2X4R) is associated with glial cell activation and inflammation, the purpose of this study is to investigate the effects of naringin on P2X4 receptor expression on satellite glial cells (SGCs) and its possible mechanisms. ATP promoted the SGC activation and upregulated P2X4R expression; naringin inhibited SGC activation, decreased expression of P2X4R, P38 MAPK/ERK, and NF-κB, and reduced levels of Ca2+, TNF-α, and IL-1β in SGCs in an ATP-containing environment. These findings suggest that naringin attenuates the ATP-induced SGC activation and reduces P2X4R expression via the Ca2+-P38 MAPK/ERK-NF-κB pathway.

• MeSH
• Adenosine Triphosphate metabolism   pharmacology   MeSH
• Rats MeSH
• p38 Mitogen-Activated Protein Kinases metabolism   pharmacology   MeSH
• Neuroglia metabolism   MeSH
• NF-kappa B * metabolism   MeSH
• Animals, Newborn MeSH
• Rats, Sprague-Dawley MeSH
• Receptors, Purinergic P2X4 * genetics   metabolism   MeSH
• Ganglia, Spinal metabolism   MeSH
• Calcium metabolism   pharmacology   MeSH
• Inflammation MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Ependymal cells, a dormant population of ciliated progenitors found within the central canal of the spinal cord, undergo significant alterations after spinal cord injury (SCI). Understanding the molecular events that induce ependymal cell activation after SCI represents the first step toward controlling the response of the endogenous regenerative machinery in damaged tissues. This response involves the activation of specific signaling pathways in the spinal cord that promotes self-renewal, proliferation, and differentiation. We review our current understanding of the signaling pathways and molecular events that mediate the SCI-induced activation of ependymal cells by focusing on the roles of some cell adhesion molecules, cellular membrane receptors, ion channels (and their crosstalk), and transcription factors. An orchestrated response regulating the expression of receptors and ion channels fine-tunes and coordinates the activation of ependymal cells after SCI or cell transplantation. Understanding the major players in the activation of ependymal cells may help us to understand whether these cells represent a critical source of cells contributing to cellular replacement and tissue regeneration after SCI. A more complete understanding of the role and function of individual signaling pathways in endogenous spinal cord progenitors may foster the development of novel targeted therapies to induce the regeneration of the injured spinal cord.

• MeSH
• Ependyma metabolism   MeSH
• Ion Channels metabolism   MeSH
• Humans MeSH
• Spinal Cord MeSH
• Neuroglia metabolism   MeSH
• Spinal Cord Injuries * therapy   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

NG2 glia display wide proliferation and differentiation potential under physiological and pathological conditions. Here, we examined these two features following different types of brain disorders such as focal cerebral ischemia (FCI), cortical stab wound (SW), and demyelination (DEMY) in 3-month-old mice, in which NG2 glia are labeled by tdTomato under the Cspg4 promoter. To compare NG2 glia expression profiles following different CNS injuries, we employed single-cell RT-qPCR and self-organizing Kohonen map analysis of tdTomato-positive cells isolated from the uninjured cortex/corpus callosum and those after specific injury. Such approach enabled us to distinguish two main cell populations (NG2 glia, oligodendrocytes), each of them comprising four distinct subpopulations. The gene expression profiling revealed that a subpopulation of NG2 glia expressing GFAP, a marker of reactive astrocytes, is only present transiently after FCI. However, following less severe injuries, namely the SW and DEMY, subpopulations mirroring different stages of oligodendrocyte maturation markedly prevail. Such injury-dependent incidence of distinct subpopulations was also confirmed by immunohistochemistry. To characterize this unique subpopulation of transient astrocyte-like NG2 glia, we used single-cell RNA-sequencing analysis and to disclose their basic membrane properties, the patch-clamp technique was employed. Overall, we have proved that astrocyte-like NG2 glia are a specific subpopulation of NG2 glia emerging transiently only following FCI. These cells, located in the postischemic glial scar, are active in the cell cycle and display a current pattern similar to that identified in cortical astrocytes. Astrocyte-like NG2 glia may represent important players in glial scar formation and repair processes, following ischemia.

• MeSH
• Astrocytes * metabolism   MeSH
• Gliosis pathology   MeSH
• Brain Ischemia * metabolism   MeSH
• Mice MeSH
• Neuroglia metabolism   MeSH
• Oligodendroglia pathology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Schwann cell grafts support axonal growth following spinal cord injury, but a boundary forms between the implanted cells and host astrocytes. Axons are reluctant to exit the graft tissue in large part due to the surrounding inhibitory environment containing chondroitin sulphate proteoglycans (CSPGs). We use a lentiviral chondroitinase ABC, capable of being secreted from mammalian cells (mChABC), to examine the repercussions of CSPG digestion upon Schwann cell behaviour in vitro. We show that mChABC transduced Schwann cells robustly secrete substantial quantities of the enzyme causing large-scale CSPG digestion, facilitating the migration and adhesion of Schwann cells on inhibitory aggrecan and astrocytic substrates. Importantly, we show that secretion of the engineered enzyme can aid the intermingling of cells at the Schwann cell-astrocyte boundary, enabling growth of neurites over the putative graft/host interface. These data were echoed in vivo. This study demonstrates the profound effect of the enzyme on cellular motility, growth and migration. This provides a cellular mechanism for mChABC induced functional and behavioural recovery shown in in vivo studies. Importantly, we provide in vitro evidence that mChABC gene therapy is equally or more effective at producing these effects as a one-time application of commercially available ChABC.

• MeSH
• Astrocytes metabolism   MeSH
• Axons metabolism   MeSH
• Cell Adhesion MeSH
• Central Nervous System metabolism   MeSH
• Chondroitin ABC Lyase metabolism   MeSH
• Chondroitin Sulfate Proteoglycans metabolism   MeSH
• Genetic Therapy MeSH
• Integrins metabolism   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Lentivirus enzymology   MeSH
• Neurites metabolism   MeSH
• Neuroglia metabolism   MeSH
• Neurons metabolism   MeSH
• Peripheral Nervous System metabolism   MeSH
• Cell Movement MeSH
• Spinal Cord Injuries physiopathology   MeSH
• Rats, Sprague-Dawley MeSH
• Nerve Regeneration drug effects   MeSH
• Schwann Cells metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Glial cells activated by peripheral nerve injury contribute to the induction and maintenance of neuropathic pain by releasing neuromodulating cytokines and chemokines. We investigated the activation of microglia and astrocytes as well as the cellular distribution of the chemokine CCL2 and its receptor CCR2 in the trigeminal subnucleus caudalis (TSC) ipsilateral and contralateral to infraorbital nerve ligature (IONL). The left infraorbital nerve was ligated under aseptic conditions, and sham controls were operated without nerve ligature. Tactile hypersensitivity was significantly increased bilaterally in vibrissal pads of both sham- and IONL-operated animals from day 1 to 7 and tended to normalize in sham controls surviving for 14 days. Activated microglial cells significantly increased bilaterally in the TSC of both sham- and IONL-operated animals with a marked but gradual increase in the ipsilateral TSC from 1 to 7 days followed by a decrease by day 14. In contrast, robust activation of astrocytes was found bilaterally in the TSC of IONL-operated rats from 3 to 14 days with a transient activation in the ipsilateral TSC of sham-operated animals. Cellular distribution of CCL2 varied with survival time. CCL2 immunofluorescence was detected in neurons within 3 days and in astrocytes at later time points. In contrast, CCR2 was found only in astrocytes at all time points with CCR2 intensity being dominant in the ipsilateral TSC. In summary, our results reveal bilateral activation of microglial cells and astrocytes as well as changes in the cellular distribution of CCL2 and its receptor CCR2 in the TSC during the development and maintenance of orofacial neuropathic pain.

• MeSH
• Chemokine CCL2 metabolism   MeSH
• Rats MeSH
• Disease Models, Animal MeSH
• Neuralgia metabolism   MeSH
• Neuroglia metabolism   MeSH
• Rats, Wistar MeSH
• Receptors, CCR2 metabolism   MeSH
• Substantia Gelatinosa metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

A highly water soluble, nano-formulated curcumin was used for the treatment of the experimental model of spinal cord injury (SCI) in rats. Nanocurcumin and a vehicle nanocarrier as a control, were delivered both locally, immediately after the spinal cord injury, and intraperitoneally during the 4 consecutive weeks after SCI. The efficacy of the treatment was assessed using behavioral tests, which were performed during the experiment, weekly for 9 weeks. The behavioral tests (BBB, flat beam test, rotarod, motoRater) revealed a significant improvement in the nanocurcumin treated group, compared to the nanocarrier control. An immunohistochemical analysis of the spinal cord tissue was performed at the end of the experiment and this proved a significant preservation of the white matter tissue, a reduced area of glial scaring and a higher amount of newly sprouted axons in the nanocurcumin treated group. The expression of endogenous genes (Sort1, Fgf2, Irf5, Mrc1, Olig2, Casp3, Gap43, Gfap, Vegf, Nfkβ) and interleukins (IL-1β, TNF-α, IL-6, IL-12, CCL-5, IL-11, IL-10, IL-13) was evaluated by qPCR and showed changes in the expression of the inflammatory cytokines in the first two weeks after SCI.

• MeSH
• White Matter drug effects   metabolism   pathology   MeSH
• Cicatrix drug therapy   metabolism   pathology   MeSH
• Rats MeSH
• Curcumin administration & dosage   MeSH
• Inflammation Mediators antagonists & inhibitors   metabolism   MeSH
• Nanoparticles administration & dosage   MeSH
• Neuroglia drug effects   metabolism   pathology   MeSH
• Spinal Cord Injuries drug therapy   metabolism   pathology   MeSH
• Rats, Wistar MeSH
• Drug Compounding MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Polycomb repressive complexes maintain transcriptional repression of genes encoding crucial developmental regulators through chromatin modification. Here we investigated the role of Polycomb repressive complex 2 (PRC2) in retinal development by inactivating its key components Eed and Ezh2. Conditional deletion of Ezh2 resulted in a partial loss of PRC2 function and accelerated differentiation of Müller glial cells. In contrast, inactivation of Eed led to the ablation of PRC2 function at early postnatal stage. Cell proliferation was reduced and retinal progenitor cells were significantly decreased in this mutant, which subsequently caused depletion of Müller glia, bipolar, and rod photoreceptor cells, primarily generated from postnatal retinal progenitor cells. Interestingly, the proportion of amacrine cells was dramatically increased at postnatal stages in the Eed-deficient retina. In accordance, multiple transcription factors controlling amacrine cell differentiation were upregulated. Furthermore, ChIP-seq analysis showed that these deregulated genes contained bivalent chromatin (H3K27me3+ H3K4me3+). Our results suggest that PRC2 is required for proliferation in order to maintain the retinal progenitor cells at postnatal stages and for retinal differentiation by controlling amacrine cell generation.

• MeSH
• Cell Differentiation physiology   MeSH
• Chromatin metabolism   MeSH
• Enhancer of Zeste Homolog 2 Protein metabolism   MeSH
• Histones metabolism   MeSH
• Stem Cells cytology   metabolism   MeSH
• Methylation MeSH
• Mice MeSH
• Neurogenesis MeSH
• Neuroglia metabolism   MeSH
• Polycomb Repressive Complex 2 metabolism   MeSH
• Cell Proliferation MeSH
• Retina metabolism   physiology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH