Neuroglia, Volume 5, Issue 4 (December 2024) – 9 articles

Background: Chronic hypoperfusion is a risk factor for neurodegenerative diseases. However, the sequence of events driving ischemia-induced functional changes in a cell-specific manner is unclear. Methods: To address this gap in knowledge, we used the bilateral common carotid artery stenosis (BCAS) mouse model, and evaluated progressive functional changes to neurons, arterioles, astrocytes, and microglial cells at 14 and 28 days post-BCAS surgery. To assess the neuro-glio-vascular response to an acute ischemic insult, brain slices were superfused with low O₂ conditions. Using whole-cell patch-clamp electrophysiology, we measured basic membrane properties (e.g., resting membrane potential, capacitance, input resistance) in cortical pyramidal neurons. The activity of astrocytes was evaluated by monitoring Ca²⁺ from Aldh1l1-CreERT2; R26-lsl-GCaMP6f mice. Vascular reactivity to low O₂ from the BCAS mice was also assessed ex vivo. Results: Our data showed no changes to the basic membrane properties of cortical pyramidal neurons. On the other hand, astrocyte activity was characterized by a progressive increase in the resting Ca²⁺. Notably, at 14 and 28 days post-BCAS, there was an increased expression of anti-inflammatory-related markers (IL-10, S100A10, TRPA1, and Nrf2). These data suggest that, in young mice, BCAS-induced increases in resting Ca²⁺ were associated with the expression of neuroprotective signals. Contrary to observations in glial cells, vascular function was impaired post-BCAS surgery, as shown by a blunted vasodilatory response to low O₂ and the vasodilatory signal, adenosine. Conclusions: Together, these data suggest that, in young mice, BCAS leads to vascular dysfunction (e.g., impaired vasodilation in parenchymal arterioles), and in the absence of neuronal dysfunction, mild ischemia is associated with the activation of glial-derived neuroprotective signals. Full article

Neurodegenerative diseases represent a significant global health burden, characterized by progressive loss of neuronal function and structure. While traditionally viewed as primarily neuronal disorders, recent research has highlighted the crucial roles of neuroglia-astrocytes, microglia, and oligodendrocytes in the pathogenesis and progression of these diseases. This review explores the dual nature of glial cells in neurodegenerative processes, focusing on their protective and potentially harmful functions in Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and other neurodegenerative disorders. We examine the complex interactions between different glial cell types and neurons, highlighting recent discoveries in glial-neuronal metabolic coupling, neuroinflammation, and protein aggregation. Advanced technologies, such as single-cell RNA sequencing and spatial transcriptomics, have revealed unprecedented glial heterogeneity and disease-specific glial states, reshaping our understanding of these cells’ roles in health and disease. The review also discusses emerging concepts in neuroglial research, including the role of extracellular vesicles in disease propagation, epigenetic regulation of glial function, and the application of artificial intelligence in glial biology. Finally, we explore the therapeutic implications of targeting glia in neurodegenerative diseases, addressing both the promising avenues and challenges in developing glial-focused interventions. By integrating recent advances in neuroglial research, this review provides a comprehensive overview of the field and highlights future directions for research and therapeutic development. Understanding the complex roles of neuroglia in neurodegenerative diseases is crucial for developing more effective treatments and ultimately improving patient outcomes. Full article

Parkinsonism is a clinical syndrome characterized by akinesia/bradykinesia, muscle rigidity, resting tremor, and postural instability. Within the group of parkinsonisms is Parkinson’s disease, also known as neurodegenerative parkinsonian syndrome. The group of atypical parkinsonisms was established due to the existence of sporadic parkinsonisms that do not share the exact etiology of Parkinson’s disease. Additionally, parkinsonisms that arise from causes other than neurodegeneration have been classified as secondary parkinsonisms. With this in mind, given the diversity of etiologies that can trigger parkinsonism, it is crucial to understand the symptomatology and its relationship with the basal ganglia (including damage to the nigrostriatal pathway, neuroinflammation, and neuronal damage). Only then will it be possible to propose appropriate treatments for each variant of parkinsonism. Full article

Background: Neuroinflammation has long been implicated in the progression of amyloid beta (Aβ) accumulation and the decline of cognitive function in Alzheimer’s disease (AD). The phenotype balance between A1 (toxic) and A2 (safe) microglial phenotypes to toxic illness in AD has become a hot research topic at present. Currently, many transcription factors, downstream signaling pathways, and molecular mechanisms that regulate the polarization of microglia are being explored. Furthermore, microglia may also exert a complex role in AD through the transformation of Aβ plaques or debris clearance, reflected in Aβ phagocytosis. One of the mediators of neuroinflammation in AD is the activated microglia. Therefore, the regulation of microglial function may be the key to successfully treating AD. Methods: This paper is a review article. PubMed, Embase, Scopus, and research meeting abstracts were searched up to 2024 for studies of microglia and neuroinflammation in Alzheimer’s Disease. Systematic information retrieval was performed, and appropriate studies were isolated based on important information available in the studies. The information from each of the articles was understood and extracted to form a database. Results: The similar neuropathological results between several animals and AD cases show the possibility of implementing microglia-related changes as an earlier diagnostic marker for AD in humans. The gene sets identified in various transcriptomic studies further foster this avenue of research by offering potential targets for therapeutic development. Substantial evidence, both in vitro and in vivo, has suggested that the loss of the normal A2 phenotype and the activation of toxic A1 microglia contribute to neurodegeneration in AD. Conclusions: Promoting or restoring the polarization of microglia towards the A2 phenotype may thus represent an effective therapeutic strategy for ameliorating neuroinflammation and progressive neurocognitive impairments. Multiple studies suggest that microglia-associated neuroinflammation at a special stage could also be protective, and, therefore, intervention should be delicate so that a beneficial response is retained. Full article

Background/Objectives: Wnt signaling pathways are essential in various biological processes, including embryonic development and tissue homeostasis, and are implicated in many diseases. The R-Spondin (RSpo) family, particularly RSpo1, plays a significant role in modulating Wnt signaling. This study aims to explore how RSpo1 binding to astrocytic LGR6 receptors influences central nervous system (CNS) homeostasis, particularly in the context of inflammation. Methods: Human-induced pluripotent stem cell-derived astrocytes were treated with RSpo1 to assess its impact on inflammatory cytokine release. A proteomic analysis was conducted using a Human Cytokine Array Kit to measure differential protein expression. Pathway enrichment analysis was performed to identify affected signaling pathways. Results: RSpo1 treatment led to a suppression of inflammatory cytokines such as IL-10, IFN-γ, and IL-23 in astrocytes, while TNF-α and CXCL12 levels were increased. Pathway analysis revealed significant alterations in key signaling pathways, including cytokine–cytokine receptor interaction, chemokine signaling, and TNF signaling pathways, suggesting RSpo1’s role in modulating immune responses within the CNS. Conclusions: RSpo1 significantly influences inflammatory responses in astrocytes by modulating cytokine release and altering key signaling pathways. These findings enhance our understanding of the interaction between cell-specific Wnt signaling and CNS inflammation, suggesting potential therapeutic applications of RSpo1 in neuroinflammatory and neurodegenerative diseases. Full article

Microglia, the unique and motile immune cells of the central nervous system (CNS), function as a security guard in maintaining CNS homeostasis, primarily through calcium signaling. The calcium dynamics in microglia control important functions such as phagocytosis, cytokine release, and migration. Calcium dysregulation in microglia has been linked to several CNS disorders, like Alzheimer’s disease (AD), Parkinson’s disease (PD), multiple sclerosis (MS), and ischemic stroke (IS). Calcium entering through channels such as voltage-gated calcium channels (VGCCs), store-operated calcium entry (SOCE), and transient receptor potential (TRP) channels is essential for microglial activation and pro-inflammatory responses. Under pathological conditions, like the formation of amyloid-β plaques in AD, aggregation of α-synuclein in PD, and oxidative stress in MS, calcium dysregulation exacerbates neuroinflammation, mitochondrial dysfunction, and neurodegeneration. Therapeutic strategies targeting calcium signaling pathways, using calcium channel blockers and antioxidant interventions, show promise for alleviating microglial activation and slowing down disease progression. This review summarizes the underlying mechanisms of microglial calcium dysregulation and potential therapeutic benefits for restoring microglial calcium balance in CNS disorders. Full article

Introduction: Mitophagy, the selective degradation of damaged mitochondria, is essential for maintaining cellular health and function, particularly in high-energy demanding post-mitotic cells like neurons and in microglial cells. Aging results in impaired mitophagy, leading to mitochondrial dysfunction, oxidative stress, the release of damage-associated proteins (DAMPs), and neuroinflammation, which contribute to neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Mitochondrial dysfunction also contributes to the pathophysiology of depression by affecting synaptic plasticity, increasing neuroinflammation, and heightening oxidative stress. Aim: In this review, we summarize the recent developments on mechanisms of mitophagy, its therapeutic role in neuroprotection, and its implications in aging and neuroinflammation, complemented by future research requirements and implications. Result/Discussion: Therapeutic strategies that promote mitochondrial health, including enhancing mitophagy and mitochondrial biogenesis, show promise in treating neurodegenerative diseases and depression. Recent findings have emphasized therapeutic strategies to modulate mitophagy, such as pharmacological agents like urolithin A and rapamycin, genetic interventions such as PINK1/Parkin gene therapy, mitochondrial transplantation, and lifestyle and dietary interventions such as caloric restriction, exercise, and dietary supplements such as resveratrol and CoQ10. Key regulators of mitophagy, including the PINK1/Parkin pathway and various proteins like BNIP3, NIX, and FUNDC1, which facilitate the removal of damaged mitochondria, play a crucial role. Conclusions: These results highlight the importance of understanding the interplay between mitophagy and neuroinflammation and show that modulation of mitophagy can reduce oxidative stress and improve neuroinflammatory outcomes and depression in age-related neurodegenerative diseases. However, despite significant progress, challenges remain in understanding the underlying molecular mechanisms of mitophagy and its therapeutic regulation in aging disorders. Full article

Central nervous system (CNS) neoplasms are a vast and diverse group of tumors in adults with variable prognoses depending on histology and increasingly understood molecular features. There has been a major paradigm shift in the approach towards these neoplasms ever since the implications of these molecular features have been recognized. Gliomas are the major group of primary CNS neoplasms in adults, and glioblastomas are a significant cause of morbidity and mortality, especially in older patients. Apart from gliomas, meningiomas and pituitary tumors are other major groups. This review aims to elucidate the role of imaging in the screening, diagnosis, management, and follow-up of major primary CNS neoplasms, with an elaborate discussion on the role of artificial intelligence and advanced imaging techniques and future directions likely to play a pivotal role in this ever-evolving subspecialty of oncology. Full article

Introduction: Acute brain injury is one of the most important causes of morbidity, mortality and disability worldwide. Time is the most important aspect of acute brain injury management. In this context, biomarkers could mitigate the limitations of neuroimaging. Neuro-biomarkers could be used both to diagnose intracranial pathology and to predict the effectiveness of treatment applications. Aim: The aim of this review is to describe the role of various and specific markers of brain damage with particular emphasis on acute brain injury and stroke. Results/discussion: The diagnostic and prognostic value of modern biomarkers remains relatively questionable, although grouping biomarkers into panels is improving their usefulness. The groups of biomarkers that will be analyzed include astrocytic, axonal, neuronal as well as extracellular biomarkers. Conclusion: Future studies will demonstrate the utility of neuro-biomarkers in the diagnosis, prognosis and therapeutic monitoring of patients with acute brain injury in the intensive care unit. Full article